Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Resizable virtual memory filesystem for Linux. |
| 3 | * |
| 4 | * Copyright (C) 2000 Linus Torvalds. |
| 5 | * 2000 Transmeta Corp. |
| 6 | * 2000-2001 Christoph Rohland |
| 7 | * 2000-2001 SAP AG |
| 8 | * 2002 Red Hat Inc. |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 9 | * Copyright (C) 2002-2011 Hugh Dickins. |
| 10 | * Copyright (C) 2011 Google Inc. |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 11 | * Copyright (C) 2002-2005 VERITAS Software Corporation. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | * Copyright (C) 2004 Andi Kleen, SuSE Labs |
| 13 | * |
| 14 | * Extended attribute support for tmpfs: |
| 15 | * Copyright (c) 2004, Luke Kenneth Casson Leighton <lkcl@lkcl.net> |
| 16 | * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> |
| 17 | * |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 18 | * tiny-shmem: |
| 19 | * Copyright (c) 2004, 2008 Matt Mackall <mpm@selenic.com> |
| 20 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | * This file is released under the GPL. |
| 22 | */ |
| 23 | |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 24 | #include <linux/fs.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/vfs.h> |
| 27 | #include <linux/mount.h> |
Andrew Morton | 250297e | 2013-04-29 15:06:12 -0700 | [diff] [blame] | 28 | #include <linux/ramfs.h> |
Hugh Dickins | caefba1 | 2009-04-13 14:40:12 -0700 | [diff] [blame] | 29 | #include <linux/pagemap.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 30 | #include <linux/file.h> |
| 31 | #include <linux/mm.h> |
Ingo Molnar | 174cd4b | 2017-02-02 19:15:33 +0100 | [diff] [blame] | 32 | #include <linux/sched/signal.h> |
Paul Gortmaker | b95f1b31 | 2011-10-16 02:01:52 -0400 | [diff] [blame] | 33 | #include <linux/export.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 34 | #include <linux/swap.h> |
Christoph Hellwig | e2e40f2 | 2015-02-22 08:58:50 -0800 | [diff] [blame] | 35 | #include <linux/uio.h> |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 36 | #include <linux/khugepaged.h> |
Mike Kravetz | 749df87 | 2017-09-06 16:24:16 -0700 | [diff] [blame] | 37 | #include <linux/hugetlb.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 38 | |
Andrea Arcangeli | 95cc09d | 2017-02-22 15:43:31 -0800 | [diff] [blame] | 39 | #include <asm/tlbflush.h> /* for arch/microblaze update_mmu_cache() */ |
| 40 | |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 41 | static struct vfsmount *shm_mnt; |
| 42 | |
| 43 | #ifdef CONFIG_SHMEM |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | /* |
| 45 | * This virtual memory filesystem is heavily based on the ramfs. It |
| 46 | * extends ramfs by the ability to use swap and honor resource limits |
| 47 | * which makes it a completely usable filesystem. |
| 48 | */ |
| 49 | |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 50 | #include <linux/xattr.h> |
Christoph Hellwig | a569425 | 2007-07-17 04:04:28 -0700 | [diff] [blame] | 51 | #include <linux/exportfs.h> |
Christoph Hellwig | 1c7c474 | 2009-11-03 16:44:44 +0100 | [diff] [blame] | 52 | #include <linux/posix_acl.h> |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 53 | #include <linux/posix_acl_xattr.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | #include <linux/mman.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | #include <linux/string.h> |
| 56 | #include <linux/slab.h> |
| 57 | #include <linux/backing-dev.h> |
| 58 | #include <linux/shmem_fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | #include <linux/blkdev.h> |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 61 | #include <linux/pagevec.h> |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 62 | #include <linux/percpu_counter.h> |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 63 | #include <linux/falloc.h> |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 64 | #include <linux/splice.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | #include <linux/security.h> |
| 66 | #include <linux/swapops.h> |
| 67 | #include <linux/mempolicy.h> |
| 68 | #include <linux/namei.h> |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 69 | #include <linux/ctype.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 70 | #include <linux/migrate.h> |
Christoph Lameter | c1f60a5 | 2006-09-25 23:31:11 -0700 | [diff] [blame] | 71 | #include <linux/highmem.h> |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 72 | #include <linux/seq_file.h> |
Mimi Zohar | 9256292 | 2008-10-07 14:00:12 -0400 | [diff] [blame] | 73 | #include <linux/magic.h> |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 74 | #include <linux/syscalls.h> |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 75 | #include <linux/fcntl.h> |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 76 | #include <uapi/linux/memfd.h> |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 77 | #include <linux/userfaultfd_k.h> |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 78 | #include <linux/rmap.h> |
Amir Goldstein | 2b4db79 | 2017-05-18 15:29:33 +0300 | [diff] [blame] | 79 | #include <linux/uuid.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 80 | |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 81 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | #include <asm/pgtable.h> |
| 83 | |
Mel Gorman | dd56b04 | 2015-11-06 16:28:43 -0800 | [diff] [blame] | 84 | #include "internal.h" |
| 85 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 86 | #define BLOCKS_PER_PAGE (PAGE_SIZE/512) |
| 87 | #define VM_ACCT(size) (PAGE_ALIGN(size) >> PAGE_SHIFT) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | /* Pretend that each entry is of this size in directory's i_size */ |
| 90 | #define BOGO_DIRENT_SIZE 20 |
| 91 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 92 | /* Symlink up to this size is kmalloc'ed instead of using a swappable page */ |
| 93 | #define SHORT_SYMLINK_LEN 128 |
| 94 | |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 95 | /* |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 96 | * shmem_fallocate communicates with shmem_fault or shmem_writepage via |
| 97 | * inode->i_private (with i_mutex making sure that it has only one user at |
| 98 | * a time): we would prefer not to enlarge the shmem inode just for that. |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 99 | */ |
| 100 | struct shmem_falloc { |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 101 | wait_queue_head_t *waitq; /* faults into hole wait for punch to end */ |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 102 | pgoff_t start; /* start of range currently being fallocated */ |
| 103 | pgoff_t next; /* the next page offset to be fallocated */ |
| 104 | pgoff_t nr_falloced; /* how many new pages have been fallocated */ |
| 105 | pgoff_t nr_unswapped; /* how often writepage refused to swap out */ |
| 106 | }; |
| 107 | |
Andrew Morton | b76db73 | 2008-02-08 04:21:49 -0800 | [diff] [blame] | 108 | #ifdef CONFIG_TMPFS |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 109 | static unsigned long shmem_default_max_blocks(void) |
| 110 | { |
| 111 | return totalram_pages / 2; |
| 112 | } |
| 113 | |
| 114 | static unsigned long shmem_default_max_inodes(void) |
| 115 | { |
| 116 | return min(totalram_pages - totalhigh_pages, totalram_pages / 2); |
| 117 | } |
Andrew Morton | b76db73 | 2008-02-08 04:21:49 -0800 | [diff] [blame] | 118 | #endif |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 119 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 120 | static bool shmem_should_replace_page(struct page *page, gfp_t gfp); |
| 121 | static int shmem_replace_page(struct page **pagep, gfp_t gfp, |
| 122 | struct shmem_inode_info *info, pgoff_t index); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 123 | static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 124 | struct page **pagep, enum sgp_type sgp, |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 125 | gfp_t gfp, struct vm_area_struct *vma, |
| 126 | struct vm_fault *vmf, int *fault_type); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 127 | |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 128 | int shmem_getpage(struct inode *inode, pgoff_t index, |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 129 | struct page **pagep, enum sgp_type sgp) |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 130 | { |
| 131 | return shmem_getpage_gfp(inode, index, pagep, sgp, |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 132 | mapping_gfp_mask(inode->i_mapping), NULL, NULL, NULL); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 133 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb) |
| 136 | { |
| 137 | return sb->s_fs_info; |
| 138 | } |
| 139 | |
| 140 | /* |
| 141 | * shmem_file_setup pre-accounts the whole fixed size of a VM object, |
| 142 | * for shared memory and for shared anonymous (/dev/zero) mappings |
| 143 | * (unless MAP_NORESERVE and sysctl_overcommit_memory <= 1), |
| 144 | * consistent with the pre-accounting of private mappings ... |
| 145 | */ |
| 146 | static inline int shmem_acct_size(unsigned long flags, loff_t size) |
| 147 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 148 | return (flags & VM_NORESERVE) ? |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 149 | 0 : security_vm_enough_memory_mm(current->mm, VM_ACCT(size)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | } |
| 151 | |
| 152 | static inline void shmem_unacct_size(unsigned long flags, loff_t size) |
| 153 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 154 | if (!(flags & VM_NORESERVE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | vm_unacct_memory(VM_ACCT(size)); |
| 156 | } |
| 157 | |
Konstantin Khlebnikov | 7714251 | 2014-08-06 16:06:34 -0700 | [diff] [blame] | 158 | static inline int shmem_reacct_size(unsigned long flags, |
| 159 | loff_t oldsize, loff_t newsize) |
| 160 | { |
| 161 | if (!(flags & VM_NORESERVE)) { |
| 162 | if (VM_ACCT(newsize) > VM_ACCT(oldsize)) |
| 163 | return security_vm_enough_memory_mm(current->mm, |
| 164 | VM_ACCT(newsize) - VM_ACCT(oldsize)); |
| 165 | else if (VM_ACCT(newsize) < VM_ACCT(oldsize)) |
| 166 | vm_unacct_memory(VM_ACCT(oldsize) - VM_ACCT(newsize)); |
| 167 | } |
| 168 | return 0; |
| 169 | } |
| 170 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | /* |
| 172 | * ... whereas tmpfs objects are accounted incrementally as |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 173 | * pages are allocated, in order to allow large sparse files. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | * shmem_getpage reports shmem_acct_block failure as -ENOSPC not -ENOMEM, |
| 175 | * so that a failure on a sparse tmpfs mapping will give SIGBUS not OOM. |
| 176 | */ |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 177 | static inline int shmem_acct_block(unsigned long flags, long pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 179 | if (!(flags & VM_NORESERVE)) |
| 180 | return 0; |
| 181 | |
| 182 | return security_vm_enough_memory_mm(current->mm, |
| 183 | pages * VM_ACCT(PAGE_SIZE)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | } |
| 185 | |
| 186 | static inline void shmem_unacct_blocks(unsigned long flags, long pages) |
| 187 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 188 | if (flags & VM_NORESERVE) |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 189 | vm_unacct_memory(pages * VM_ACCT(PAGE_SIZE)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | } |
| 191 | |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 192 | static inline bool shmem_inode_acct_block(struct inode *inode, long pages) |
| 193 | { |
| 194 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 195 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
| 196 | |
| 197 | if (shmem_acct_block(info->flags, pages)) |
| 198 | return false; |
| 199 | |
| 200 | if (sbinfo->max_blocks) { |
| 201 | if (percpu_counter_compare(&sbinfo->used_blocks, |
| 202 | sbinfo->max_blocks - pages) > 0) |
| 203 | goto unacct; |
| 204 | percpu_counter_add(&sbinfo->used_blocks, pages); |
| 205 | } |
| 206 | |
| 207 | return true; |
| 208 | |
| 209 | unacct: |
| 210 | shmem_unacct_blocks(info->flags, pages); |
| 211 | return false; |
| 212 | } |
| 213 | |
| 214 | static inline void shmem_inode_unacct_blocks(struct inode *inode, long pages) |
| 215 | { |
| 216 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 217 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
| 218 | |
| 219 | if (sbinfo->max_blocks) |
| 220 | percpu_counter_sub(&sbinfo->used_blocks, pages); |
| 221 | shmem_unacct_blocks(info->flags, pages); |
| 222 | } |
| 223 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 224 | static const struct super_operations shmem_ops; |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 225 | static const struct address_space_operations shmem_aops; |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 226 | static const struct file_operations shmem_file_operations; |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 227 | static const struct inode_operations shmem_inode_operations; |
| 228 | static const struct inode_operations shmem_dir_inode_operations; |
| 229 | static const struct inode_operations shmem_special_inode_operations; |
Alexey Dobriyan | f0f37e2 | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 230 | static const struct vm_operations_struct shmem_vm_ops; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 231 | static struct file_system_type shmem_fs_type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | |
Mike Rapoport | b0506e4 | 2017-02-22 15:43:28 -0800 | [diff] [blame] | 233 | bool vma_is_shmem(struct vm_area_struct *vma) |
| 234 | { |
| 235 | return vma->vm_ops == &shmem_vm_ops; |
| 236 | } |
| 237 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | static LIST_HEAD(shmem_swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 239 | static DEFINE_MUTEX(shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 241 | static int shmem_reserve_inode(struct super_block *sb) |
| 242 | { |
| 243 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 244 | if (sbinfo->max_inodes) { |
| 245 | spin_lock(&sbinfo->stat_lock); |
| 246 | if (!sbinfo->free_inodes) { |
| 247 | spin_unlock(&sbinfo->stat_lock); |
| 248 | return -ENOSPC; |
| 249 | } |
| 250 | sbinfo->free_inodes--; |
| 251 | spin_unlock(&sbinfo->stat_lock); |
| 252 | } |
| 253 | return 0; |
| 254 | } |
| 255 | |
| 256 | static void shmem_free_inode(struct super_block *sb) |
| 257 | { |
| 258 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 259 | if (sbinfo->max_inodes) { |
| 260 | spin_lock(&sbinfo->stat_lock); |
| 261 | sbinfo->free_inodes++; |
| 262 | spin_unlock(&sbinfo->stat_lock); |
| 263 | } |
| 264 | } |
| 265 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 266 | /** |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 267 | * shmem_recalc_inode - recalculate the block usage of an inode |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | * @inode: inode to recalc |
| 269 | * |
| 270 | * We have to calculate the free blocks since the mm can drop |
| 271 | * undirtied hole pages behind our back. |
| 272 | * |
| 273 | * But normally info->alloced == inode->i_mapping->nrpages + info->swapped |
| 274 | * So mm freed is info->alloced - (inode->i_mapping->nrpages + info->swapped) |
| 275 | * |
| 276 | * It has to be called with the spinlock held. |
| 277 | */ |
| 278 | static void shmem_recalc_inode(struct inode *inode) |
| 279 | { |
| 280 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 281 | long freed; |
| 282 | |
| 283 | freed = info->alloced - info->swapped - inode->i_mapping->nrpages; |
| 284 | if (freed > 0) { |
| 285 | info->alloced -= freed; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 286 | inode->i_blocks -= freed * BLOCKS_PER_PAGE; |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 287 | shmem_inode_unacct_blocks(inode, freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | } |
| 289 | } |
| 290 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 291 | bool shmem_charge(struct inode *inode, long pages) |
| 292 | { |
| 293 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 294 | unsigned long flags; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 295 | |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 296 | if (!shmem_inode_acct_block(inode, pages)) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 297 | return false; |
Mike Rapoport | b1cc94a | 2017-09-06 16:22:56 -0700 | [diff] [blame] | 298 | |
Hugh Dickins | 98f1ae1 | 2018-11-30 14:10:29 -0800 | [diff] [blame] | 299 | /* nrpages adjustment first, then shmem_recalc_inode() when balanced */ |
| 300 | inode->i_mapping->nrpages += pages; |
| 301 | |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 302 | spin_lock_irqsave(&info->lock, flags); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 303 | info->alloced += pages; |
| 304 | inode->i_blocks += pages * BLOCKS_PER_PAGE; |
| 305 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 306 | spin_unlock_irqrestore(&info->lock, flags); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 307 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 308 | return true; |
| 309 | } |
| 310 | |
| 311 | void shmem_uncharge(struct inode *inode, long pages) |
| 312 | { |
| 313 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 314 | unsigned long flags; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 315 | |
Hugh Dickins | 98f1ae1 | 2018-11-30 14:10:29 -0800 | [diff] [blame] | 316 | /* nrpages adjustment done by __delete_from_page_cache() or caller */ |
| 317 | |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 318 | spin_lock_irqsave(&info->lock, flags); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 319 | info->alloced -= pages; |
| 320 | inode->i_blocks -= pages * BLOCKS_PER_PAGE; |
| 321 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 322 | spin_unlock_irqrestore(&info->lock, flags); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 323 | |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 324 | shmem_inode_unacct_blocks(inode, pages); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 325 | } |
| 326 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 327 | /* |
| 328 | * Replace item expected in radix tree by a new item, while holding tree lock. |
| 329 | */ |
| 330 | static int shmem_radix_tree_replace(struct address_space *mapping, |
| 331 | pgoff_t index, void *expected, void *replacement) |
| 332 | { |
Johannes Weiner | f794243 | 2016-12-12 16:43:41 -0800 | [diff] [blame] | 333 | struct radix_tree_node *node; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 334 | void **pslot; |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 335 | void *item; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 336 | |
| 337 | VM_BUG_ON(!expected); |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 338 | VM_BUG_ON(!replacement); |
Johannes Weiner | f794243 | 2016-12-12 16:43:41 -0800 | [diff] [blame] | 339 | item = __radix_tree_lookup(&mapping->page_tree, index, &node, &pslot); |
| 340 | if (!item) |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 341 | return -ENOENT; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 342 | if (item != expected) |
| 343 | return -ENOENT; |
Johannes Weiner | 4d693d0 | 2016-12-12 16:43:49 -0800 | [diff] [blame] | 344 | __radix_tree_replace(&mapping->page_tree, node, pslot, |
| 345 | replacement, NULL, NULL); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 346 | return 0; |
| 347 | } |
| 348 | |
| 349 | /* |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 350 | * Sometimes, before we decide whether to proceed or to fail, we must check |
| 351 | * that an entry was not already brought back from swap by a racing thread. |
| 352 | * |
| 353 | * Checking page is not enough: by the time a SwapCache page is locked, it |
| 354 | * might be reused, and again be SwapCache, using the same swap as before. |
| 355 | */ |
| 356 | static bool shmem_confirm_swap(struct address_space *mapping, |
| 357 | pgoff_t index, swp_entry_t swap) |
| 358 | { |
| 359 | void *item; |
| 360 | |
| 361 | rcu_read_lock(); |
| 362 | item = radix_tree_lookup(&mapping->page_tree, index); |
| 363 | rcu_read_unlock(); |
| 364 | return item == swp_to_radix_entry(swap); |
| 365 | } |
| 366 | |
| 367 | /* |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 368 | * Definitions for "huge tmpfs": tmpfs mounted with the huge= option |
| 369 | * |
| 370 | * SHMEM_HUGE_NEVER: |
| 371 | * disables huge pages for the mount; |
| 372 | * SHMEM_HUGE_ALWAYS: |
| 373 | * enables huge pages for the mount; |
| 374 | * SHMEM_HUGE_WITHIN_SIZE: |
| 375 | * only allocate huge pages if the page will be fully within i_size, |
| 376 | * also respect fadvise()/madvise() hints; |
| 377 | * SHMEM_HUGE_ADVISE: |
| 378 | * only allocate huge pages if requested with fadvise()/madvise(); |
| 379 | */ |
| 380 | |
| 381 | #define SHMEM_HUGE_NEVER 0 |
| 382 | #define SHMEM_HUGE_ALWAYS 1 |
| 383 | #define SHMEM_HUGE_WITHIN_SIZE 2 |
| 384 | #define SHMEM_HUGE_ADVISE 3 |
| 385 | |
| 386 | /* |
| 387 | * Special values. |
| 388 | * Only can be set via /sys/kernel/mm/transparent_hugepage/shmem_enabled: |
| 389 | * |
| 390 | * SHMEM_HUGE_DENY: |
| 391 | * disables huge on shm_mnt and all mounts, for emergency use; |
| 392 | * SHMEM_HUGE_FORCE: |
| 393 | * enables huge on shm_mnt and all mounts, w/o needing option, for testing; |
| 394 | * |
| 395 | */ |
| 396 | #define SHMEM_HUGE_DENY (-1) |
| 397 | #define SHMEM_HUGE_FORCE (-2) |
| 398 | |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 399 | #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 400 | /* ifdef here to avoid bloating shmem.o when not necessary */ |
| 401 | |
| 402 | int shmem_huge __read_mostly; |
| 403 | |
Jérémy Lefaure | f1f5929 | 2016-12-12 16:43:23 -0800 | [diff] [blame] | 404 | #if defined(CONFIG_SYSFS) || defined(CONFIG_TMPFS) |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 405 | static int shmem_parse_huge(const char *str) |
| 406 | { |
| 407 | if (!strcmp(str, "never")) |
| 408 | return SHMEM_HUGE_NEVER; |
| 409 | if (!strcmp(str, "always")) |
| 410 | return SHMEM_HUGE_ALWAYS; |
| 411 | if (!strcmp(str, "within_size")) |
| 412 | return SHMEM_HUGE_WITHIN_SIZE; |
| 413 | if (!strcmp(str, "advise")) |
| 414 | return SHMEM_HUGE_ADVISE; |
| 415 | if (!strcmp(str, "deny")) |
| 416 | return SHMEM_HUGE_DENY; |
| 417 | if (!strcmp(str, "force")) |
| 418 | return SHMEM_HUGE_FORCE; |
| 419 | return -EINVAL; |
| 420 | } |
| 421 | |
| 422 | static const char *shmem_format_huge(int huge) |
| 423 | { |
| 424 | switch (huge) { |
| 425 | case SHMEM_HUGE_NEVER: |
| 426 | return "never"; |
| 427 | case SHMEM_HUGE_ALWAYS: |
| 428 | return "always"; |
| 429 | case SHMEM_HUGE_WITHIN_SIZE: |
| 430 | return "within_size"; |
| 431 | case SHMEM_HUGE_ADVISE: |
| 432 | return "advise"; |
| 433 | case SHMEM_HUGE_DENY: |
| 434 | return "deny"; |
| 435 | case SHMEM_HUGE_FORCE: |
| 436 | return "force"; |
| 437 | default: |
| 438 | VM_BUG_ON(1); |
| 439 | return "bad_val"; |
| 440 | } |
| 441 | } |
Jérémy Lefaure | f1f5929 | 2016-12-12 16:43:23 -0800 | [diff] [blame] | 442 | #endif |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 443 | |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 444 | static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, |
| 445 | struct shrink_control *sc, unsigned long nr_to_split) |
| 446 | { |
| 447 | LIST_HEAD(list), *pos, *next; |
Kirill A. Shutemov | 253fd0f | 2017-02-03 13:13:15 -0800 | [diff] [blame] | 448 | LIST_HEAD(to_remove); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 449 | struct inode *inode; |
| 450 | struct shmem_inode_info *info; |
| 451 | struct page *page; |
| 452 | unsigned long batch = sc ? sc->nr_to_scan : 128; |
| 453 | int removed = 0, split = 0; |
| 454 | |
| 455 | if (list_empty(&sbinfo->shrinklist)) |
| 456 | return SHRINK_STOP; |
| 457 | |
| 458 | spin_lock(&sbinfo->shrinklist_lock); |
| 459 | list_for_each_safe(pos, next, &sbinfo->shrinklist) { |
| 460 | info = list_entry(pos, struct shmem_inode_info, shrinklist); |
| 461 | |
| 462 | /* pin the inode */ |
| 463 | inode = igrab(&info->vfs_inode); |
| 464 | |
| 465 | /* inode is about to be evicted */ |
| 466 | if (!inode) { |
| 467 | list_del_init(&info->shrinklist); |
| 468 | removed++; |
| 469 | goto next; |
| 470 | } |
| 471 | |
| 472 | /* Check if there's anything to gain */ |
| 473 | if (round_up(inode->i_size, PAGE_SIZE) == |
| 474 | round_up(inode->i_size, HPAGE_PMD_SIZE)) { |
Kirill A. Shutemov | 253fd0f | 2017-02-03 13:13:15 -0800 | [diff] [blame] | 475 | list_move(&info->shrinklist, &to_remove); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 476 | removed++; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 477 | goto next; |
| 478 | } |
| 479 | |
| 480 | list_move(&info->shrinklist, &list); |
| 481 | next: |
| 482 | if (!--batch) |
| 483 | break; |
| 484 | } |
| 485 | spin_unlock(&sbinfo->shrinklist_lock); |
| 486 | |
Kirill A. Shutemov | 253fd0f | 2017-02-03 13:13:15 -0800 | [diff] [blame] | 487 | list_for_each_safe(pos, next, &to_remove) { |
| 488 | info = list_entry(pos, struct shmem_inode_info, shrinklist); |
| 489 | inode = &info->vfs_inode; |
| 490 | list_del_init(&info->shrinklist); |
| 491 | iput(inode); |
| 492 | } |
| 493 | |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 494 | list_for_each_safe(pos, next, &list) { |
| 495 | int ret; |
| 496 | |
| 497 | info = list_entry(pos, struct shmem_inode_info, shrinklist); |
| 498 | inode = &info->vfs_inode; |
| 499 | |
Kirill A. Shutemov | f5dad04 | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 500 | if (nr_to_split && split >= nr_to_split) |
| 501 | goto leave; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 502 | |
Kirill A. Shutemov | f5dad04 | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 503 | page = find_get_page(inode->i_mapping, |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 504 | (inode->i_size & HPAGE_PMD_MASK) >> PAGE_SHIFT); |
| 505 | if (!page) |
| 506 | goto drop; |
| 507 | |
Kirill A. Shutemov | f5dad04 | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 508 | /* No huge page at the end of the file: nothing to split */ |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 509 | if (!PageTransHuge(page)) { |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 510 | put_page(page); |
| 511 | goto drop; |
| 512 | } |
| 513 | |
Kirill A. Shutemov | f5dad04 | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 514 | /* |
| 515 | * Leave the inode on the list if we failed to lock |
| 516 | * the page at this time. |
| 517 | * |
| 518 | * Waiting for the lock may lead to deadlock in the |
| 519 | * reclaim path. |
| 520 | */ |
| 521 | if (!trylock_page(page)) { |
| 522 | put_page(page); |
| 523 | goto leave; |
| 524 | } |
| 525 | |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 526 | ret = split_huge_page(page); |
| 527 | unlock_page(page); |
| 528 | put_page(page); |
| 529 | |
Kirill A. Shutemov | f5dad04 | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 530 | /* If split failed leave the inode on the list */ |
| 531 | if (ret) |
| 532 | goto leave; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 533 | |
| 534 | split++; |
| 535 | drop: |
| 536 | list_del_init(&info->shrinklist); |
| 537 | removed++; |
Kirill A. Shutemov | f5dad04 | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 538 | leave: |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 539 | iput(inode); |
| 540 | } |
| 541 | |
| 542 | spin_lock(&sbinfo->shrinklist_lock); |
| 543 | list_splice_tail(&list, &sbinfo->shrinklist); |
| 544 | sbinfo->shrinklist_len -= removed; |
| 545 | spin_unlock(&sbinfo->shrinklist_lock); |
| 546 | |
| 547 | return split; |
| 548 | } |
| 549 | |
| 550 | static long shmem_unused_huge_scan(struct super_block *sb, |
| 551 | struct shrink_control *sc) |
| 552 | { |
| 553 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 554 | |
| 555 | if (!READ_ONCE(sbinfo->shrinklist_len)) |
| 556 | return SHRINK_STOP; |
| 557 | |
| 558 | return shmem_unused_huge_shrink(sbinfo, sc, 0); |
| 559 | } |
| 560 | |
| 561 | static long shmem_unused_huge_count(struct super_block *sb, |
| 562 | struct shrink_control *sc) |
| 563 | { |
| 564 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 565 | return READ_ONCE(sbinfo->shrinklist_len); |
| 566 | } |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 567 | #else /* !CONFIG_TRANSPARENT_HUGE_PAGECACHE */ |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 568 | |
| 569 | #define shmem_huge SHMEM_HUGE_DENY |
| 570 | |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 571 | static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, |
| 572 | struct shrink_control *sc, unsigned long nr_to_split) |
| 573 | { |
| 574 | return 0; |
| 575 | } |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 576 | #endif /* CONFIG_TRANSPARENT_HUGE_PAGECACHE */ |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 577 | |
| 578 | /* |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 579 | * Like add_to_page_cache_locked, but error if expected item has gone. |
| 580 | */ |
| 581 | static int shmem_add_to_page_cache(struct page *page, |
| 582 | struct address_space *mapping, |
Wang Sheng-Hui | fed400a | 2014-08-06 16:07:26 -0700 | [diff] [blame] | 583 | pgoff_t index, void *expected) |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 584 | { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 585 | int error, nr = hpage_nr_pages(page); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 586 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 587 | VM_BUG_ON_PAGE(PageTail(page), page); |
| 588 | VM_BUG_ON_PAGE(index != round_down(index, nr), page); |
Sasha Levin | 309381fea | 2014-01-23 15:52:54 -0800 | [diff] [blame] | 589 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
| 590 | VM_BUG_ON_PAGE(!PageSwapBacked(page), page); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 591 | VM_BUG_ON(expected && PageTransHuge(page)); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 592 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 593 | page_ref_add(page, nr); |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 594 | page->mapping = mapping; |
| 595 | page->index = index; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 596 | |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 597 | spin_lock_irq(&mapping->tree_lock); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 598 | if (PageTransHuge(page)) { |
| 599 | void __rcu **results; |
| 600 | pgoff_t idx; |
| 601 | int i; |
| 602 | |
| 603 | error = 0; |
| 604 | if (radix_tree_gang_lookup_slot(&mapping->page_tree, |
| 605 | &results, &idx, index, 1) && |
| 606 | idx < index + HPAGE_PMD_NR) { |
| 607 | error = -EEXIST; |
| 608 | } |
| 609 | |
| 610 | if (!error) { |
| 611 | for (i = 0; i < HPAGE_PMD_NR; i++) { |
| 612 | error = radix_tree_insert(&mapping->page_tree, |
| 613 | index + i, page + i); |
| 614 | VM_BUG_ON(error); |
| 615 | } |
| 616 | count_vm_event(THP_FILE_ALLOC); |
| 617 | } |
| 618 | } else if (!expected) { |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 619 | error = radix_tree_insert(&mapping->page_tree, index, page); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 620 | } else { |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 621 | error = shmem_radix_tree_replace(mapping, index, expected, |
| 622 | page); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 623 | } |
| 624 | |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 625 | if (!error) { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 626 | mapping->nrpages += nr; |
| 627 | if (PageTransHuge(page)) |
Mel Gorman | 11fb998 | 2016-07-28 15:46:20 -0700 | [diff] [blame] | 628 | __inc_node_page_state(page, NR_SHMEM_THPS); |
| 629 | __mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr); |
| 630 | __mod_node_page_state(page_pgdat(page), NR_SHMEM, nr); |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 631 | spin_unlock_irq(&mapping->tree_lock); |
| 632 | } else { |
| 633 | page->mapping = NULL; |
| 634 | spin_unlock_irq(&mapping->tree_lock); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 635 | page_ref_sub(page, nr); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 636 | } |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 637 | return error; |
| 638 | } |
| 639 | |
| 640 | /* |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 641 | * Like delete_from_page_cache, but substitutes swap for page. |
| 642 | */ |
| 643 | static void shmem_delete_from_page_cache(struct page *page, void *radswap) |
| 644 | { |
| 645 | struct address_space *mapping = page->mapping; |
| 646 | int error; |
| 647 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 648 | VM_BUG_ON_PAGE(PageCompound(page), page); |
| 649 | |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 650 | spin_lock_irq(&mapping->tree_lock); |
| 651 | error = shmem_radix_tree_replace(mapping, page->index, page, radswap); |
| 652 | page->mapping = NULL; |
| 653 | mapping->nrpages--; |
Mel Gorman | 11fb998 | 2016-07-28 15:46:20 -0700 | [diff] [blame] | 654 | __dec_node_page_state(page, NR_FILE_PAGES); |
| 655 | __dec_node_page_state(page, NR_SHMEM); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 656 | spin_unlock_irq(&mapping->tree_lock); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 657 | put_page(page); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 658 | BUG_ON(error); |
| 659 | } |
| 660 | |
| 661 | /* |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 662 | * Remove swap entry from radix tree, free the swap and its page cache. |
| 663 | */ |
| 664 | static int shmem_free_swap(struct address_space *mapping, |
| 665 | pgoff_t index, void *radswap) |
| 666 | { |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 667 | void *old; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 668 | |
| 669 | spin_lock_irq(&mapping->tree_lock); |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 670 | old = radix_tree_delete_item(&mapping->page_tree, index, radswap); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 671 | spin_unlock_irq(&mapping->tree_lock); |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 672 | if (old != radswap) |
| 673 | return -ENOENT; |
| 674 | free_swap_and_cache(radix_to_swp_entry(radswap)); |
| 675 | return 0; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 676 | } |
| 677 | |
| 678 | /* |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 679 | * Determine (in bytes) how many of the shmem object's pages mapped by the |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 680 | * given offsets are swapped out. |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 681 | * |
| 682 | * This is safe to call without i_mutex or mapping->tree_lock thanks to RCU, |
| 683 | * as long as the inode doesn't go away and racy results are not a problem. |
| 684 | */ |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 685 | unsigned long shmem_partial_swap_usage(struct address_space *mapping, |
| 686 | pgoff_t start, pgoff_t end) |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 687 | { |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 688 | struct radix_tree_iter iter; |
| 689 | void **slot; |
| 690 | struct page *page; |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 691 | unsigned long swapped = 0; |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 692 | |
| 693 | rcu_read_lock(); |
| 694 | |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 695 | radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) { |
| 696 | if (iter.index >= end) |
| 697 | break; |
| 698 | |
| 699 | page = radix_tree_deref_slot(slot); |
| 700 | |
Matthew Wilcox | 2cf938a | 2016-03-17 14:22:03 -0700 | [diff] [blame] | 701 | if (radix_tree_deref_retry(page)) { |
| 702 | slot = radix_tree_iter_retry(&iter); |
| 703 | continue; |
| 704 | } |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 705 | |
| 706 | if (radix_tree_exceptional_entry(page)) |
| 707 | swapped++; |
| 708 | |
| 709 | if (need_resched()) { |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 710 | slot = radix_tree_iter_resume(slot, &iter); |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 711 | cond_resched_rcu(); |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 712 | } |
| 713 | } |
| 714 | |
| 715 | rcu_read_unlock(); |
| 716 | |
| 717 | return swapped << PAGE_SHIFT; |
| 718 | } |
| 719 | |
| 720 | /* |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 721 | * Determine (in bytes) how many of the shmem object's pages mapped by the |
| 722 | * given vma is swapped out. |
| 723 | * |
| 724 | * This is safe to call without i_mutex or mapping->tree_lock thanks to RCU, |
| 725 | * as long as the inode doesn't go away and racy results are not a problem. |
| 726 | */ |
| 727 | unsigned long shmem_swap_usage(struct vm_area_struct *vma) |
| 728 | { |
| 729 | struct inode *inode = file_inode(vma->vm_file); |
| 730 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 731 | struct address_space *mapping = inode->i_mapping; |
| 732 | unsigned long swapped; |
| 733 | |
| 734 | /* Be careful as we don't hold info->lock */ |
| 735 | swapped = READ_ONCE(info->swapped); |
| 736 | |
| 737 | /* |
| 738 | * The easier cases are when the shmem object has nothing in swap, or |
| 739 | * the vma maps it whole. Then we can simply use the stats that we |
| 740 | * already track. |
| 741 | */ |
| 742 | if (!swapped) |
| 743 | return 0; |
| 744 | |
| 745 | if (!vma->vm_pgoff && vma->vm_end - vma->vm_start >= inode->i_size) |
| 746 | return swapped << PAGE_SHIFT; |
| 747 | |
| 748 | /* Here comes the more involved part */ |
| 749 | return shmem_partial_swap_usage(mapping, |
| 750 | linear_page_index(vma, vma->vm_start), |
| 751 | linear_page_index(vma, vma->vm_end)); |
| 752 | } |
| 753 | |
| 754 | /* |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 755 | * SysV IPC SHM_UNLOCK restore Unevictable pages to their evictable lists. |
| 756 | */ |
| 757 | void shmem_unlock_mapping(struct address_space *mapping) |
| 758 | { |
| 759 | struct pagevec pvec; |
| 760 | pgoff_t indices[PAGEVEC_SIZE]; |
| 761 | pgoff_t index = 0; |
| 762 | |
| 763 | pagevec_init(&pvec, 0); |
| 764 | /* |
| 765 | * Minor point, but we might as well stop if someone else SHM_LOCKs it. |
| 766 | */ |
| 767 | while (!mapping_unevictable(mapping)) { |
| 768 | /* |
| 769 | * Avoid pagevec_lookup(): find_get_pages() returns 0 as if it |
| 770 | * has finished, if it hits a row of PAGEVEC_SIZE swap entries. |
| 771 | */ |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 772 | pvec.nr = find_get_entries(mapping, index, |
| 773 | PAGEVEC_SIZE, pvec.pages, indices); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 774 | if (!pvec.nr) |
| 775 | break; |
| 776 | index = indices[pvec.nr - 1] + 1; |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 777 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 778 | check_move_unevictable_pages(pvec.pages, pvec.nr); |
| 779 | pagevec_release(&pvec); |
| 780 | cond_resched(); |
| 781 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 782 | } |
| 783 | |
| 784 | /* |
| 785 | * Remove range of pages and swap entries from radix tree, and free them. |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 786 | * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate. |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 787 | */ |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 788 | static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, |
| 789 | bool unfalloc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 790 | { |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 791 | struct address_space *mapping = inode->i_mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 792 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 793 | pgoff_t start = (lstart + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 794 | pgoff_t end = (lend + 1) >> PAGE_SHIFT; |
| 795 | unsigned int partial_start = lstart & (PAGE_SIZE - 1); |
| 796 | unsigned int partial_end = (lend + 1) & (PAGE_SIZE - 1); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 797 | struct pagevec pvec; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 798 | pgoff_t indices[PAGEVEC_SIZE]; |
| 799 | long nr_swaps_freed = 0; |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 800 | pgoff_t index; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 801 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 802 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 803 | if (lend == -1) |
| 804 | end = -1; /* unsigned, so actually very big */ |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 805 | |
| 806 | pagevec_init(&pvec, 0); |
| 807 | index = start; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 808 | while (index < end) { |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 809 | pvec.nr = find_get_entries(mapping, index, |
| 810 | min(end - index, (pgoff_t)PAGEVEC_SIZE), |
| 811 | pvec.pages, indices); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 812 | if (!pvec.nr) |
| 813 | break; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 814 | for (i = 0; i < pagevec_count(&pvec); i++) { |
| 815 | struct page *page = pvec.pages[i]; |
| 816 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 817 | index = indices[i]; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 818 | if (index >= end) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 819 | break; |
| 820 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 821 | if (radix_tree_exceptional_entry(page)) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 822 | if (unfalloc) |
| 823 | continue; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 824 | nr_swaps_freed += !shmem_free_swap(mapping, |
| 825 | index, page); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 826 | continue; |
| 827 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 828 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 829 | VM_BUG_ON_PAGE(page_to_pgoff(page) != index, page); |
| 830 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 831 | if (!trylock_page(page)) |
| 832 | continue; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 833 | |
| 834 | if (PageTransTail(page)) { |
| 835 | /* Middle of THP: zero out the page */ |
| 836 | clear_highpage(page); |
| 837 | unlock_page(page); |
| 838 | continue; |
| 839 | } else if (PageTransHuge(page)) { |
| 840 | if (index == round_down(end, HPAGE_PMD_NR)) { |
| 841 | /* |
| 842 | * Range ends in the middle of THP: |
| 843 | * zero out the page |
| 844 | */ |
| 845 | clear_highpage(page); |
| 846 | unlock_page(page); |
| 847 | continue; |
| 848 | } |
| 849 | index += HPAGE_PMD_NR - 1; |
| 850 | i += HPAGE_PMD_NR - 1; |
| 851 | } |
| 852 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 853 | if (!unfalloc || !PageUptodate(page)) { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 854 | VM_BUG_ON_PAGE(PageTail(page), page); |
| 855 | if (page_mapping(page) == mapping) { |
Sasha Levin | 309381fea | 2014-01-23 15:52:54 -0800 | [diff] [blame] | 856 | VM_BUG_ON_PAGE(PageWriteback(page), page); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 857 | truncate_inode_page(mapping, page); |
| 858 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 859 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 860 | unlock_page(page); |
| 861 | } |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 862 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 863 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 864 | cond_resched(); |
| 865 | index++; |
| 866 | } |
| 867 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 868 | if (partial_start) { |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 869 | struct page *page = NULL; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 870 | shmem_getpage(inode, start - 1, &page, SGP_READ); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 871 | if (page) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 872 | unsigned int top = PAGE_SIZE; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 873 | if (start > end) { |
| 874 | top = partial_end; |
| 875 | partial_end = 0; |
| 876 | } |
| 877 | zero_user_segment(page, partial_start, top); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 878 | set_page_dirty(page); |
| 879 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 880 | put_page(page); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 881 | } |
| 882 | } |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 883 | if (partial_end) { |
| 884 | struct page *page = NULL; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 885 | shmem_getpage(inode, end, &page, SGP_READ); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 886 | if (page) { |
| 887 | zero_user_segment(page, 0, partial_end); |
| 888 | set_page_dirty(page); |
| 889 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 890 | put_page(page); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 891 | } |
| 892 | } |
| 893 | if (start >= end) |
| 894 | return; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 895 | |
| 896 | index = start; |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 897 | while (index < end) { |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 898 | cond_resched(); |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 899 | |
| 900 | pvec.nr = find_get_entries(mapping, index, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 901 | min(end - index, (pgoff_t)PAGEVEC_SIZE), |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 902 | pvec.pages, indices); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 903 | if (!pvec.nr) { |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 904 | /* If all gone or hole-punch or unfalloc, we're done */ |
| 905 | if (index == start || end != -1) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 906 | break; |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 907 | /* But if truncating, restart to make sure all gone */ |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 908 | index = start; |
| 909 | continue; |
| 910 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 911 | for (i = 0; i < pagevec_count(&pvec); i++) { |
| 912 | struct page *page = pvec.pages[i]; |
| 913 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 914 | index = indices[i]; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 915 | if (index >= end) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 916 | break; |
| 917 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 918 | if (radix_tree_exceptional_entry(page)) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 919 | if (unfalloc) |
| 920 | continue; |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 921 | if (shmem_free_swap(mapping, index, page)) { |
| 922 | /* Swap was replaced by page: retry */ |
| 923 | index--; |
| 924 | break; |
| 925 | } |
| 926 | nr_swaps_freed++; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 927 | continue; |
| 928 | } |
| 929 | |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 930 | lock_page(page); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 931 | |
| 932 | if (PageTransTail(page)) { |
| 933 | /* Middle of THP: zero out the page */ |
| 934 | clear_highpage(page); |
| 935 | unlock_page(page); |
| 936 | /* |
| 937 | * Partial thp truncate due 'start' in middle |
| 938 | * of THP: don't need to look on these pages |
| 939 | * again on !pvec.nr restart. |
| 940 | */ |
| 941 | if (index != round_down(end, HPAGE_PMD_NR)) |
| 942 | start++; |
| 943 | continue; |
| 944 | } else if (PageTransHuge(page)) { |
| 945 | if (index == round_down(end, HPAGE_PMD_NR)) { |
| 946 | /* |
| 947 | * Range ends in the middle of THP: |
| 948 | * zero out the page |
| 949 | */ |
| 950 | clear_highpage(page); |
| 951 | unlock_page(page); |
| 952 | continue; |
| 953 | } |
| 954 | index += HPAGE_PMD_NR - 1; |
| 955 | i += HPAGE_PMD_NR - 1; |
| 956 | } |
| 957 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 958 | if (!unfalloc || !PageUptodate(page)) { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 959 | VM_BUG_ON_PAGE(PageTail(page), page); |
| 960 | if (page_mapping(page) == mapping) { |
Sasha Levin | 309381fea | 2014-01-23 15:52:54 -0800 | [diff] [blame] | 961 | VM_BUG_ON_PAGE(PageWriteback(page), page); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 962 | truncate_inode_page(mapping, page); |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 963 | } else { |
| 964 | /* Page was replaced by swap: retry */ |
| 965 | unlock_page(page); |
| 966 | index--; |
| 967 | break; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 968 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 969 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 970 | unlock_page(page); |
| 971 | } |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 972 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 973 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 974 | index++; |
| 975 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 976 | |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 977 | spin_lock_irq(&info->lock); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 978 | info->swapped -= nr_swaps_freed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 980 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 981 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 982 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 983 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend) |
| 984 | { |
| 985 | shmem_undo_range(inode, lstart, lend, false); |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 986 | inode->i_ctime = inode->i_mtime = current_time(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 987 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 988 | EXPORT_SYMBOL_GPL(shmem_truncate_range); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 989 | |
David Howells | a528d35 | 2017-01-31 16:46:22 +0000 | [diff] [blame] | 990 | static int shmem_getattr(const struct path *path, struct kstat *stat, |
| 991 | u32 request_mask, unsigned int query_flags) |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 992 | { |
David Howells | a528d35 | 2017-01-31 16:46:22 +0000 | [diff] [blame] | 993 | struct inode *inode = path->dentry->d_inode; |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 994 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 995 | |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 996 | if (info->alloced - info->swapped != inode->i_mapping->nrpages) { |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 997 | spin_lock_irq(&info->lock); |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 998 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 999 | spin_unlock_irq(&info->lock); |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 1000 | } |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 1001 | generic_fillattr(inode, stat); |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 1002 | return 0; |
| 1003 | } |
| 1004 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1005 | static int shmem_setattr(struct dentry *dentry, struct iattr *attr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1006 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 1007 | struct inode *inode = d_inode(dentry); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 1008 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1009 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1010 | int error; |
| 1011 | |
Jan Kara | 31051c8 | 2016-05-26 16:55:18 +0200 | [diff] [blame] | 1012 | error = setattr_prepare(dentry, attr); |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 1013 | if (error) |
| 1014 | return error; |
| 1015 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1016 | if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { |
| 1017 | loff_t oldsize = inode->i_size; |
| 1018 | loff_t newsize = attr->ia_size; |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 1019 | |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 1020 | /* protected by i_mutex */ |
| 1021 | if ((newsize < oldsize && (info->seals & F_SEAL_SHRINK)) || |
| 1022 | (newsize > oldsize && (info->seals & F_SEAL_GROW))) |
| 1023 | return -EPERM; |
| 1024 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1025 | if (newsize != oldsize) { |
Konstantin Khlebnikov | 7714251 | 2014-08-06 16:06:34 -0700 | [diff] [blame] | 1026 | error = shmem_reacct_size(SHMEM_I(inode)->flags, |
| 1027 | oldsize, newsize); |
| 1028 | if (error) |
| 1029 | return error; |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1030 | i_size_write(inode, newsize); |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 1031 | inode->i_ctime = inode->i_mtime = current_time(inode); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1032 | } |
Josef Bacik | afa2db2 | 2015-06-24 16:58:45 -0700 | [diff] [blame] | 1033 | if (newsize <= oldsize) { |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1034 | loff_t holebegin = round_up(newsize, PAGE_SIZE); |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 1035 | if (oldsize > holebegin) |
| 1036 | unmap_mapping_range(inode->i_mapping, |
| 1037 | holebegin, 0, 1); |
| 1038 | if (info->alloced) |
| 1039 | shmem_truncate_range(inode, |
| 1040 | newsize, (loff_t)-1); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1041 | /* unmap again to remove racily COWed private pages */ |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 1042 | if (oldsize > holebegin) |
| 1043 | unmap_mapping_range(inode->i_mapping, |
| 1044 | holebegin, 0, 1); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1045 | |
| 1046 | /* |
| 1047 | * Part of the huge page can be beyond i_size: subject |
| 1048 | * to shrink under memory pressure. |
| 1049 | */ |
| 1050 | if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) { |
| 1051 | spin_lock(&sbinfo->shrinklist_lock); |
Cong Wang | d041353 | 2017-08-10 15:24:24 -0700 | [diff] [blame] | 1052 | /* |
| 1053 | * _careful to defend against unlocked access to |
| 1054 | * ->shrink_list in shmem_unused_huge_shrink() |
| 1055 | */ |
| 1056 | if (list_empty_careful(&info->shrinklist)) { |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1057 | list_add_tail(&info->shrinklist, |
| 1058 | &sbinfo->shrinklist); |
| 1059 | sbinfo->shrinklist_len++; |
| 1060 | } |
| 1061 | spin_unlock(&sbinfo->shrinklist_lock); |
| 1062 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1063 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1064 | } |
| 1065 | |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 1066 | setattr_copy(inode, attr); |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 1067 | if (attr->ia_valid & ATTR_MODE) |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 1068 | error = posix_acl_chmod(inode, inode->i_mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1069 | return error; |
| 1070 | } |
| 1071 | |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 1072 | static void shmem_evict_inode(struct inode *inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1073 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1075 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 1077 | if (inode->i_mapping->a_ops == &shmem_aops) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1078 | shmem_unacct_size(info->flags, inode->i_size); |
| 1079 | inode->i_size = 0; |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 1080 | shmem_truncate_range(inode, 0, (loff_t)-1); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1081 | if (!list_empty(&info->shrinklist)) { |
| 1082 | spin_lock(&sbinfo->shrinklist_lock); |
| 1083 | if (!list_empty(&info->shrinklist)) { |
| 1084 | list_del_init(&info->shrinklist); |
| 1085 | sbinfo->shrinklist_len--; |
| 1086 | } |
| 1087 | spin_unlock(&sbinfo->shrinklist_lock); |
| 1088 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1089 | if (!list_empty(&info->swaplist)) { |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 1090 | mutex_lock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1091 | list_del_init(&info->swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 1092 | mutex_unlock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | } |
Al Viro | 3ed47db | 2016-01-22 18:08:52 -0500 | [diff] [blame] | 1094 | } |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 1095 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 1096 | simple_xattrs_free(&info->xattrs); |
Hugh Dickins | 0f3c42f | 2012-11-16 14:15:04 -0800 | [diff] [blame] | 1097 | WARN_ON(inode->i_blocks); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1098 | shmem_free_inode(inode->i_sb); |
Jan Kara | dbd5768 | 2012-05-03 14:48:02 +0200 | [diff] [blame] | 1099 | clear_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1100 | } |
| 1101 | |
Matthew Wilcox | 478922e | 2016-12-14 15:08:52 -0800 | [diff] [blame] | 1102 | static unsigned long find_swap_entry(struct radix_tree_root *root, void *item) |
| 1103 | { |
| 1104 | struct radix_tree_iter iter; |
| 1105 | void **slot; |
| 1106 | unsigned long found = -1; |
| 1107 | unsigned int checked = 0; |
| 1108 | |
| 1109 | rcu_read_lock(); |
| 1110 | radix_tree_for_each_slot(slot, root, &iter, 0) { |
| 1111 | if (*slot == item) { |
| 1112 | found = iter.index; |
| 1113 | break; |
| 1114 | } |
| 1115 | checked++; |
| 1116 | if ((checked % 4096) != 0) |
| 1117 | continue; |
| 1118 | slot = radix_tree_iter_resume(slot, &iter); |
| 1119 | cond_resched_rcu(); |
| 1120 | } |
| 1121 | |
| 1122 | rcu_read_unlock(); |
| 1123 | return found; |
| 1124 | } |
| 1125 | |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1126 | /* |
| 1127 | * If swap found in inode, free it and move page from swapcache to filecache. |
| 1128 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1129 | static int shmem_unuse_inode(struct shmem_inode_info *info, |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1130 | swp_entry_t swap, struct page **pagep) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1131 | { |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 1132 | struct address_space *mapping = info->vfs_inode.i_mapping; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1133 | void *radswap; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1134 | pgoff_t index; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1135 | gfp_t gfp; |
| 1136 | int error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1137 | |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1138 | radswap = swp_to_radix_entry(swap); |
Matthew Wilcox | 478922e | 2016-12-14 15:08:52 -0800 | [diff] [blame] | 1139 | index = find_swap_entry(&mapping->page_tree, radswap); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1140 | if (index == -1) |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1141 | return -EAGAIN; /* tell shmem_unuse we found nothing */ |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 1142 | |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 1143 | /* |
| 1144 | * Move _head_ to start search for next from here. |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 1145 | * But be careful: shmem_evict_inode checks list_empty without taking |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 1146 | * mutex, and there's an instant in list_move_tail when info->swaplist |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 1147 | * would appear empty, if it were the only one on shmem_swaplist. |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 1148 | */ |
| 1149 | if (shmem_swaplist.next != &info->swaplist) |
| 1150 | list_move_tail(&shmem_swaplist, &info->swaplist); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 1151 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1152 | gfp = mapping_gfp_mask(mapping); |
| 1153 | if (shmem_should_replace_page(*pagep, gfp)) { |
| 1154 | mutex_unlock(&shmem_swaplist_mutex); |
| 1155 | error = shmem_replace_page(pagep, gfp, info, index); |
| 1156 | mutex_lock(&shmem_swaplist_mutex); |
| 1157 | /* |
| 1158 | * We needed to drop mutex to make that restrictive page |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1159 | * allocation, but the inode might have been freed while we |
| 1160 | * dropped it: although a racing shmem_evict_inode() cannot |
| 1161 | * complete without emptying the radix_tree, our page lock |
| 1162 | * on this swapcache page is not enough to prevent that - |
| 1163 | * free_swap_and_cache() of our swap entry will only |
| 1164 | * trylock_page(), removing swap from radix_tree whatever. |
| 1165 | * |
| 1166 | * We must not proceed to shmem_add_to_page_cache() if the |
| 1167 | * inode has been freed, but of course we cannot rely on |
| 1168 | * inode or mapping or info to check that. However, we can |
| 1169 | * safely check if our swap entry is still in use (and here |
| 1170 | * it can't have got reused for another page): if it's still |
| 1171 | * in use, then the inode cannot have been freed yet, and we |
| 1172 | * can safely proceed (if it's no longer in use, that tells |
| 1173 | * nothing about the inode, but we don't need to unuse swap). |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1174 | */ |
| 1175 | if (!page_swapcount(*pagep)) |
| 1176 | error = -ENOENT; |
| 1177 | } |
| 1178 | |
KAMEZAWA Hiroyuki | d13d144 | 2009-01-07 18:07:56 -0800 | [diff] [blame] | 1179 | /* |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1180 | * We rely on shmem_swaplist_mutex, not only to protect the swaplist, |
| 1181 | * but also to hold up shmem_evict_inode(): so inode cannot be freed |
| 1182 | * beneath us (pagelock doesn't help until the page is in pagecache). |
KAMEZAWA Hiroyuki | d13d144 | 2009-01-07 18:07:56 -0800 | [diff] [blame] | 1183 | */ |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1184 | if (!error) |
| 1185 | error = shmem_add_to_page_cache(*pagep, mapping, index, |
Wang Sheng-Hui | fed400a | 2014-08-06 16:07:26 -0700 | [diff] [blame] | 1186 | radswap); |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 1187 | if (error != -ENOMEM) { |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1188 | /* |
| 1189 | * Truncation and eviction use free_swap_and_cache(), which |
| 1190 | * only does trylock page: if we raced, best clean up here. |
| 1191 | */ |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1192 | delete_from_swap_cache(*pagep); |
| 1193 | set_page_dirty(*pagep); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1194 | if (!error) { |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1195 | spin_lock_irq(&info->lock); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1196 | info->swapped--; |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1197 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1198 | swap_free(swap); |
| 1199 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1200 | } |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 1201 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1202 | } |
| 1203 | |
| 1204 | /* |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1205 | * Search through swapped inodes to find and replace swap by page. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1206 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1207 | int shmem_unuse(swp_entry_t swap, struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1208 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1209 | struct list_head *this, *next; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1210 | struct shmem_inode_info *info; |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1211 | struct mem_cgroup *memcg; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1212 | int error = 0; |
| 1213 | |
| 1214 | /* |
| 1215 | * There's a faint possibility that swap page was replaced before |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1216 | * caller locked it: caller will come back later with the right page. |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1217 | */ |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1218 | if (unlikely(!PageSwapCache(page) || page_private(page) != swap.val)) |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1219 | goto out; |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1220 | |
| 1221 | /* |
| 1222 | * Charge page using GFP_KERNEL while we can wait, before taking |
| 1223 | * the shmem_swaplist_mutex which might hold up shmem_writepage(). |
| 1224 | * Charged back to the user (not to caller) when swap account is used. |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1225 | */ |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1226 | error = mem_cgroup_try_charge(page, current->mm, GFP_KERNEL, &memcg, |
| 1227 | false); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1228 | if (error) |
| 1229 | goto out; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1230 | /* No radix_tree_preload: swap entry keeps a place for page in tree */ |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1231 | error = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1232 | |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 1233 | mutex_lock(&shmem_swaplist_mutex); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1234 | list_for_each_safe(this, next, &shmem_swaplist) { |
| 1235 | info = list_entry(this, struct shmem_inode_info, swaplist); |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 1236 | if (info->swapped) |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1237 | error = shmem_unuse_inode(info, swap, &page); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1238 | else |
| 1239 | list_del_init(&info->swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 1240 | cond_resched(); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1241 | if (error != -EAGAIN) |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1242 | break; |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1243 | /* found nothing in this: move on to search the next */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | } |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 1245 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1246 | |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1247 | if (error) { |
| 1248 | if (error != -ENOMEM) |
| 1249 | error = 0; |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1250 | mem_cgroup_cancel_charge(page, memcg, false); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1251 | } else |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1252 | mem_cgroup_commit_charge(page, memcg, true, false); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1253 | out: |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 1254 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1255 | put_page(page); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1256 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1257 | } |
| 1258 | |
| 1259 | /* |
| 1260 | * Move the page from the page cache to the swap cache. |
| 1261 | */ |
| 1262 | static int shmem_writepage(struct page *page, struct writeback_control *wbc) |
| 1263 | { |
| 1264 | struct shmem_inode_info *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1265 | struct address_space *mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1266 | struct inode *inode; |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1267 | swp_entry_t swap; |
| 1268 | pgoff_t index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1269 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1270 | VM_BUG_ON_PAGE(PageCompound(page), page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1271 | BUG_ON(!PageLocked(page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1272 | mapping = page->mapping; |
| 1273 | index = page->index; |
| 1274 | inode = mapping->host; |
| 1275 | info = SHMEM_I(inode); |
| 1276 | if (info->flags & VM_LOCKED) |
| 1277 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1278 | if (!total_swap_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1279 | goto redirty; |
| 1280 | |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1281 | /* |
Christoph Hellwig | 97b713b | 2015-01-14 10:42:31 +0100 | [diff] [blame] | 1282 | * Our capabilities prevent regular writeback or sync from ever calling |
| 1283 | * shmem_writepage; but a stacking filesystem might use ->writepage of |
| 1284 | * its underlying filesystem, in which case tmpfs should write out to |
| 1285 | * swap only in response to memory pressure, and not for the writeback |
| 1286 | * threads or sync. |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1287 | */ |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 1288 | if (!wbc->for_reclaim) { |
| 1289 | WARN_ON_ONCE(1); /* Still happens? Tell us about it! */ |
| 1290 | goto redirty; |
| 1291 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1292 | |
| 1293 | /* |
| 1294 | * This is somewhat ridiculous, but without plumbing a SWAP_MAP_FALLOC |
| 1295 | * value into swapfile.c, the only way we can correctly account for a |
| 1296 | * fallocated page arriving here is now to initialize it and write it. |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1297 | * |
| 1298 | * That's okay for a page already fallocated earlier, but if we have |
| 1299 | * not yet completed the fallocation, then (a) we want to keep track |
| 1300 | * of this page in case we have to undo it, and (b) it may not be a |
| 1301 | * good idea to continue anyway, once we're pushing into swap. So |
| 1302 | * reactivate the page, and let shmem_fallocate() quit when too many. |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1303 | */ |
| 1304 | if (!PageUptodate(page)) { |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1305 | if (inode->i_private) { |
| 1306 | struct shmem_falloc *shmem_falloc; |
| 1307 | spin_lock(&inode->i_lock); |
| 1308 | shmem_falloc = inode->i_private; |
| 1309 | if (shmem_falloc && |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1310 | !shmem_falloc->waitq && |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1311 | index >= shmem_falloc->start && |
| 1312 | index < shmem_falloc->next) |
| 1313 | shmem_falloc->nr_unswapped++; |
| 1314 | else |
| 1315 | shmem_falloc = NULL; |
| 1316 | spin_unlock(&inode->i_lock); |
| 1317 | if (shmem_falloc) |
| 1318 | goto redirty; |
| 1319 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1320 | clear_highpage(page); |
| 1321 | flush_dcache_page(page); |
| 1322 | SetPageUptodate(page); |
| 1323 | } |
| 1324 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 1325 | swap = get_swap_page(page); |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 1326 | if (!swap.val) |
| 1327 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1328 | |
Vladimir Davydov | 37e8435 | 2016-01-20 15:02:56 -0800 | [diff] [blame] | 1329 | if (mem_cgroup_try_charge_swap(page, swap)) |
| 1330 | goto free_swap; |
| 1331 | |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 1332 | /* |
| 1333 | * Add inode to shmem_unuse()'s list of swapped-out inodes, |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1334 | * if it's not already there. Do it now before the page is |
| 1335 | * moved to swap cache, when its pagelock no longer protects |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 1336 | * the inode from eviction. But don't unlock the mutex until |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1337 | * we've incremented swapped, because shmem_unuse_inode() will |
| 1338 | * prune a !swapped inode from the swaplist under this mutex. |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 1339 | */ |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 1340 | mutex_lock(&shmem_swaplist_mutex); |
| 1341 | if (list_empty(&info->swaplist)) |
| 1342 | list_add_tail(&info->swaplist, &shmem_swaplist); |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 1343 | |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 1344 | if (add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) { |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1345 | spin_lock_irq(&info->lock); |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1346 | shmem_recalc_inode(inode); |
| 1347 | info->swapped++; |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1348 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1349 | |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 1350 | swap_shmem_alloc(swap); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1351 | shmem_delete_from_page_cache(page, swp_to_radix_entry(swap)); |
| 1352 | |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1353 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1354 | BUG_ON(page_mapped(page)); |
Hugh Dickins | 9fab561 | 2009-03-31 15:23:33 -0700 | [diff] [blame] | 1355 | swap_writepage(page, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1356 | return 0; |
| 1357 | } |
| 1358 | |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1359 | mutex_unlock(&shmem_swaplist_mutex); |
Vladimir Davydov | 37e8435 | 2016-01-20 15:02:56 -0800 | [diff] [blame] | 1360 | free_swap: |
Minchan Kim | 75f6d6d | 2017-07-06 15:37:21 -0700 | [diff] [blame] | 1361 | put_swap_page(page, swap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1362 | redirty: |
| 1363 | set_page_dirty(page); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1364 | if (wbc->for_reclaim) |
| 1365 | return AOP_WRITEPAGE_ACTIVATE; /* Return with page locked */ |
| 1366 | unlock_page(page); |
| 1367 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1368 | } |
| 1369 | |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1370 | #if defined(CONFIG_NUMA) && defined(CONFIG_TMPFS) |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1371 | static void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1372 | { |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 1373 | char buffer[64]; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1374 | |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1375 | if (!mpol || mpol->mode == MPOL_DEFAULT) |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 1376 | return; /* show nothing */ |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1377 | |
Hugh Dickins | a7a88b2 | 2013-01-02 02:04:23 -0800 | [diff] [blame] | 1378 | mpol_to_str(buffer, sizeof(buffer), mpol); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1379 | |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 1380 | seq_printf(seq, ",mpol=%s", buffer); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1381 | } |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1382 | |
| 1383 | static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) |
| 1384 | { |
| 1385 | struct mempolicy *mpol = NULL; |
| 1386 | if (sbinfo->mpol) { |
| 1387 | spin_lock(&sbinfo->stat_lock); /* prevent replace/use races */ |
| 1388 | mpol = sbinfo->mpol; |
| 1389 | mpol_get(mpol); |
| 1390 | spin_unlock(&sbinfo->stat_lock); |
| 1391 | } |
| 1392 | return mpol; |
| 1393 | } |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1394 | #else /* !CONFIG_NUMA || !CONFIG_TMPFS */ |
| 1395 | static inline void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) |
| 1396 | { |
| 1397 | } |
| 1398 | static inline struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) |
| 1399 | { |
| 1400 | return NULL; |
| 1401 | } |
| 1402 | #endif /* CONFIG_NUMA && CONFIG_TMPFS */ |
| 1403 | #ifndef CONFIG_NUMA |
| 1404 | #define vm_policy vm_private_data |
| 1405 | #endif |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1406 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1407 | static void shmem_pseudo_vma_init(struct vm_area_struct *vma, |
| 1408 | struct shmem_inode_info *info, pgoff_t index) |
| 1409 | { |
| 1410 | /* Create a pseudo vma that just contains the policy */ |
| 1411 | vma->vm_start = 0; |
| 1412 | /* Bias interleave by inode number to distribute better across nodes */ |
| 1413 | vma->vm_pgoff = index + info->vfs_inode.i_ino; |
| 1414 | vma->vm_ops = NULL; |
| 1415 | vma->vm_policy = mpol_shared_policy_lookup(&info->policy, index); |
| 1416 | } |
| 1417 | |
| 1418 | static void shmem_pseudo_vma_destroy(struct vm_area_struct *vma) |
| 1419 | { |
| 1420 | /* Drop reference taken by mpol_shared_policy_lookup() */ |
| 1421 | mpol_cond_put(vma->vm_policy); |
| 1422 | } |
| 1423 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1424 | static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, |
| 1425 | struct shmem_inode_info *info, pgoff_t index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1426 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1427 | struct vm_area_struct pvma; |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1428 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1429 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1430 | shmem_pseudo_vma_init(&pvma, info, index); |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1431 | page = swapin_readahead(swap, gfp, &pvma, 0); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1432 | shmem_pseudo_vma_destroy(&pvma); |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1433 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1434 | return page; |
| 1435 | } |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1436 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1437 | static struct page *shmem_alloc_hugepage(gfp_t gfp, |
| 1438 | struct shmem_inode_info *info, pgoff_t index) |
| 1439 | { |
| 1440 | struct vm_area_struct pvma; |
| 1441 | struct inode *inode = &info->vfs_inode; |
| 1442 | struct address_space *mapping = inode->i_mapping; |
Geert Uytterhoeven | 4620a06 | 2016-08-03 19:58:19 +0200 | [diff] [blame] | 1443 | pgoff_t idx, hindex; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1444 | void __rcu **results; |
| 1445 | struct page *page; |
| 1446 | |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 1447 | if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1448 | return NULL; |
| 1449 | |
Geert Uytterhoeven | 4620a06 | 2016-08-03 19:58:19 +0200 | [diff] [blame] | 1450 | hindex = round_down(index, HPAGE_PMD_NR); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1451 | rcu_read_lock(); |
| 1452 | if (radix_tree_gang_lookup_slot(&mapping->page_tree, &results, &idx, |
| 1453 | hindex, 1) && idx < hindex + HPAGE_PMD_NR) { |
| 1454 | rcu_read_unlock(); |
| 1455 | return NULL; |
| 1456 | } |
| 1457 | rcu_read_unlock(); |
| 1458 | |
| 1459 | shmem_pseudo_vma_init(&pvma, info, hindex); |
| 1460 | page = alloc_pages_vma(gfp | __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN, |
| 1461 | HPAGE_PMD_ORDER, &pvma, 0, numa_node_id(), true); |
| 1462 | shmem_pseudo_vma_destroy(&pvma); |
| 1463 | if (page) |
| 1464 | prep_transhuge_page(page); |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1465 | return page; |
| 1466 | } |
| 1467 | |
| 1468 | static struct page *shmem_alloc_page(gfp_t gfp, |
| 1469 | struct shmem_inode_info *info, pgoff_t index) |
| 1470 | { |
| 1471 | struct vm_area_struct pvma; |
| 1472 | struct page *page; |
| 1473 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1474 | shmem_pseudo_vma_init(&pvma, info, index); |
| 1475 | page = alloc_page_vma(gfp, &pvma, 0); |
| 1476 | shmem_pseudo_vma_destroy(&pvma); |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1477 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1478 | return page; |
| 1479 | } |
| 1480 | |
| 1481 | static struct page *shmem_alloc_and_acct_page(gfp_t gfp, |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1482 | struct inode *inode, |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1483 | pgoff_t index, bool huge) |
| 1484 | { |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1485 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1486 | struct page *page; |
| 1487 | int nr; |
| 1488 | int err = -ENOSPC; |
| 1489 | |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 1490 | if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1491 | huge = false; |
| 1492 | nr = huge ? HPAGE_PMD_NR : 1; |
| 1493 | |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1494 | if (!shmem_inode_acct_block(inode, nr)) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1495 | goto failed; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1496 | |
| 1497 | if (huge) |
| 1498 | page = shmem_alloc_hugepage(gfp, info, index); |
| 1499 | else |
| 1500 | page = shmem_alloc_page(gfp, info, index); |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1501 | if (page) { |
| 1502 | __SetPageLocked(page); |
| 1503 | __SetPageSwapBacked(page); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1504 | return page; |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1505 | } |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1506 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1507 | err = -ENOMEM; |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1508 | shmem_inode_unacct_blocks(inode, nr); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1509 | failed: |
| 1510 | return ERR_PTR(err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1511 | } |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1512 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1513 | /* |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1514 | * When a page is moved from swapcache to shmem filecache (either by the |
| 1515 | * usual swapin of shmem_getpage_gfp(), or by the less common swapoff of |
| 1516 | * shmem_unuse_inode()), it may have been read in earlier from swap, in |
| 1517 | * ignorance of the mapping it belongs to. If that mapping has special |
| 1518 | * constraints (like the gma500 GEM driver, which requires RAM below 4GB), |
| 1519 | * we may need to copy to a suitable page before moving to filecache. |
| 1520 | * |
| 1521 | * In a future release, this may well be extended to respect cpuset and |
| 1522 | * NUMA mempolicy, and applied also to anonymous pages in do_swap_page(); |
| 1523 | * but for now it is a simple matter of zone. |
| 1524 | */ |
| 1525 | static bool shmem_should_replace_page(struct page *page, gfp_t gfp) |
| 1526 | { |
| 1527 | return page_zonenum(page) > gfp_zone(gfp); |
| 1528 | } |
| 1529 | |
| 1530 | static int shmem_replace_page(struct page **pagep, gfp_t gfp, |
| 1531 | struct shmem_inode_info *info, pgoff_t index) |
| 1532 | { |
| 1533 | struct page *oldpage, *newpage; |
| 1534 | struct address_space *swap_mapping; |
Yu Zhao | 7c1ba1a | 2018-11-30 14:09:03 -0800 | [diff] [blame] | 1535 | swp_entry_t entry; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1536 | pgoff_t swap_index; |
| 1537 | int error; |
| 1538 | |
| 1539 | oldpage = *pagep; |
Yu Zhao | 7c1ba1a | 2018-11-30 14:09:03 -0800 | [diff] [blame] | 1540 | entry.val = page_private(oldpage); |
| 1541 | swap_index = swp_offset(entry); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1542 | swap_mapping = page_mapping(oldpage); |
| 1543 | |
| 1544 | /* |
| 1545 | * We have arrived here because our zones are constrained, so don't |
| 1546 | * limit chance of success by further cpuset and node constraints. |
| 1547 | */ |
| 1548 | gfp &= ~GFP_CONSTRAINT_MASK; |
| 1549 | newpage = shmem_alloc_page(gfp, info, index); |
| 1550 | if (!newpage) |
| 1551 | return -ENOMEM; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1552 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1553 | get_page(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1554 | copy_highpage(newpage, oldpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1555 | flush_dcache_page(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1556 | |
Hugh Dickins | 9956edf | 2016-11-10 10:46:11 -0800 | [diff] [blame] | 1557 | __SetPageLocked(newpage); |
| 1558 | __SetPageSwapBacked(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1559 | SetPageUptodate(newpage); |
Yu Zhao | 7c1ba1a | 2018-11-30 14:09:03 -0800 | [diff] [blame] | 1560 | set_page_private(newpage, entry.val); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1561 | SetPageSwapCache(newpage); |
| 1562 | |
| 1563 | /* |
| 1564 | * Our caller will very soon move newpage out of swapcache, but it's |
| 1565 | * a nice clean interface for us to replace oldpage by newpage there. |
| 1566 | */ |
| 1567 | spin_lock_irq(&swap_mapping->tree_lock); |
| 1568 | error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage, |
| 1569 | newpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1570 | if (!error) { |
Mel Gorman | 11fb998 | 2016-07-28 15:46:20 -0700 | [diff] [blame] | 1571 | __inc_node_page_state(newpage, NR_FILE_PAGES); |
| 1572 | __dec_node_page_state(oldpage, NR_FILE_PAGES); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1573 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1574 | spin_unlock_irq(&swap_mapping->tree_lock); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1575 | |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1576 | if (unlikely(error)) { |
| 1577 | /* |
| 1578 | * Is this possible? I think not, now that our callers check |
| 1579 | * both PageSwapCache and page_private after getting page lock; |
| 1580 | * but be defensive. Reverse old to newpage for clear and free. |
| 1581 | */ |
| 1582 | oldpage = newpage; |
| 1583 | } else { |
Johannes Weiner | 6a93ca8 | 2016-03-15 14:57:19 -0700 | [diff] [blame] | 1584 | mem_cgroup_migrate(oldpage, newpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1585 | lru_cache_add_anon(newpage); |
| 1586 | *pagep = newpage; |
| 1587 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1588 | |
| 1589 | ClearPageSwapCache(oldpage); |
| 1590 | set_page_private(oldpage, 0); |
| 1591 | |
| 1592 | unlock_page(oldpage); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1593 | put_page(oldpage); |
| 1594 | put_page(oldpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1595 | return error; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1596 | } |
| 1597 | |
| 1598 | /* |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1599 | * shmem_getpage_gfp - find page in cache, or get from swap, or allocate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1600 | * |
| 1601 | * If we allocate a new one we do not mark it dirty. That's up to the |
| 1602 | * vm. If we swap it in we mark it dirty since we also free the swap |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1603 | * entry since a page cannot live in both the swap and page cache. |
| 1604 | * |
| 1605 | * fault_mm and fault_type are only supplied by shmem_fault: |
| 1606 | * otherwise they are NULL. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1607 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1608 | static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1609 | struct page **pagep, enum sgp_type sgp, gfp_t gfp, |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 1610 | struct vm_area_struct *vma, struct vm_fault *vmf, int *fault_type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1611 | { |
| 1612 | struct address_space *mapping = inode->i_mapping; |
Arnd Bergmann | 23f919d | 2016-12-12 16:42:28 -0800 | [diff] [blame] | 1613 | struct shmem_inode_info *info = SHMEM_I(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1614 | struct shmem_sb_info *sbinfo; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1615 | struct mm_struct *charge_mm; |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1616 | struct mem_cgroup *memcg; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1617 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1618 | swp_entry_t swap; |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 1619 | enum sgp_type sgp_huge = sgp; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1620 | pgoff_t hindex = index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1621 | int error; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1622 | int once = 0; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1623 | int alloced = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1624 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1625 | if (index > (MAX_LFS_FILESIZE >> PAGE_SHIFT)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1626 | return -EFBIG; |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 1627 | if (sgp == SGP_NOHUGE || sgp == SGP_HUGE) |
| 1628 | sgp = SGP_CACHE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1629 | repeat: |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1630 | swap.val = 0; |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 1631 | page = find_lock_entry(mapping, index); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1632 | if (radix_tree_exceptional_entry(page)) { |
| 1633 | swap = radix_to_swp_entry(page); |
| 1634 | page = NULL; |
| 1635 | } |
| 1636 | |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1637 | if (sgp <= SGP_CACHE && |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1638 | ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1639 | error = -EINVAL; |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1640 | goto unlock; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1641 | } |
| 1642 | |
Hugh Dickins | 66d2f4d | 2014-07-02 15:22:38 -0700 | [diff] [blame] | 1643 | if (page && sgp == SGP_WRITE) |
| 1644 | mark_page_accessed(page); |
| 1645 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1646 | /* fallocated page? */ |
| 1647 | if (page && !PageUptodate(page)) { |
| 1648 | if (sgp != SGP_READ) |
| 1649 | goto clear; |
| 1650 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1651 | put_page(page); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1652 | page = NULL; |
| 1653 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1654 | if (page || (sgp == SGP_READ && !swap.val)) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1655 | *pagep = page; |
| 1656 | return 0; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1657 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1658 | |
| 1659 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1660 | * Fast cache lookup did not find it: |
| 1661 | * bring it back from swap or allocate. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1662 | */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1663 | sbinfo = SHMEM_SB(inode->i_sb); |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 1664 | charge_mm = vma ? vma->vm_mm : current->mm; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1665 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1666 | if (swap.val) { |
| 1667 | /* Look it up and read it in.. */ |
Huang Ying | ec56017 | 2017-09-06 16:24:36 -0700 | [diff] [blame] | 1668 | page = lookup_swap_cache(swap, NULL, 0); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1669 | if (!page) { |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1670 | /* Or update major stats only when swapin succeeds?? */ |
| 1671 | if (fault_type) { |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1672 | *fault_type |= VM_FAULT_MAJOR; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1673 | count_vm_event(PGMAJFAULT); |
Roman Gushchin | 2262185 | 2017-07-06 15:40:25 -0700 | [diff] [blame] | 1674 | count_memcg_event_mm(charge_mm, PGMAJFAULT); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1675 | } |
| 1676 | /* Here we actually start the io */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1677 | page = shmem_swapin(swap, gfp, info, index); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1678 | if (!page) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1679 | error = -ENOMEM; |
| 1680 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1681 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1682 | } |
| 1683 | |
| 1684 | /* We have to do this with page locked to prevent races */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1685 | lock_page(page); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1686 | if (!PageSwapCache(page) || page_private(page) != swap.val || |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1687 | !shmem_confirm_swap(mapping, index, swap)) { |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1688 | error = -EEXIST; /* try again */ |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1689 | goto unlock; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1690 | } |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1691 | if (!PageUptodate(page)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1692 | error = -EIO; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1693 | goto failed; |
| 1694 | } |
| 1695 | wait_on_page_writeback(page); |
| 1696 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1697 | if (shmem_should_replace_page(page, gfp)) { |
| 1698 | error = shmem_replace_page(&page, gfp, info, index); |
| 1699 | if (error) |
| 1700 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1701 | } |
| 1702 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1703 | error = mem_cgroup_try_charge(page, charge_mm, gfp, &memcg, |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1704 | false); |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1705 | if (!error) { |
Hugh Dickins | aa3b189 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1706 | error = shmem_add_to_page_cache(page, mapping, index, |
Wang Sheng-Hui | fed400a | 2014-08-06 16:07:26 -0700 | [diff] [blame] | 1707 | swp_to_radix_entry(swap)); |
Hugh Dickins | 215c02b | 2012-11-16 14:15:03 -0800 | [diff] [blame] | 1708 | /* |
| 1709 | * We already confirmed swap under page lock, and make |
| 1710 | * no memory allocation here, so usually no possibility |
| 1711 | * of error; but free_swap_and_cache() only trylocks a |
| 1712 | * page, so it is just possible that the entry has been |
| 1713 | * truncated or holepunched since swap was confirmed. |
| 1714 | * shmem_undo_range() will have done some of the |
| 1715 | * unaccounting, now delete_from_swap_cache() will do |
Vladimir Davydov | 93aa7d9 | 2015-02-11 15:24:59 -0800 | [diff] [blame] | 1716 | * the rest. |
Hugh Dickins | 215c02b | 2012-11-16 14:15:03 -0800 | [diff] [blame] | 1717 | * Reset swap.val? No, leave it so "failed" goes back to |
| 1718 | * "repeat": reading a hole and writing should succeed. |
| 1719 | */ |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1720 | if (error) { |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1721 | mem_cgroup_cancel_charge(page, memcg, false); |
Hugh Dickins | 215c02b | 2012-11-16 14:15:03 -0800 | [diff] [blame] | 1722 | delete_from_swap_cache(page); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1723 | } |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1724 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1725 | if (error) |
| 1726 | goto failed; |
| 1727 | |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1728 | mem_cgroup_commit_charge(page, memcg, true, false); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1729 | |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1730 | spin_lock_irq(&info->lock); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1731 | info->swapped--; |
| 1732 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1733 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1734 | |
Hugh Dickins | 66d2f4d | 2014-07-02 15:22:38 -0700 | [diff] [blame] | 1735 | if (sgp == SGP_WRITE) |
| 1736 | mark_page_accessed(page); |
| 1737 | |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1738 | delete_from_swap_cache(page); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1739 | set_page_dirty(page); |
| 1740 | swap_free(swap); |
| 1741 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1742 | } else { |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 1743 | if (vma && userfaultfd_missing(vma)) { |
| 1744 | *fault_type = handle_userfault(vmf, VM_UFFD_MISSING); |
| 1745 | return 0; |
| 1746 | } |
| 1747 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1748 | /* shmem_symlink() */ |
| 1749 | if (mapping->a_ops != &shmem_aops) |
| 1750 | goto alloc_nohuge; |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 1751 | if (shmem_huge == SHMEM_HUGE_DENY || sgp_huge == SGP_NOHUGE) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1752 | goto alloc_nohuge; |
| 1753 | if (shmem_huge == SHMEM_HUGE_FORCE) |
| 1754 | goto alloc_huge; |
| 1755 | switch (sbinfo->huge) { |
| 1756 | loff_t i_size; |
| 1757 | pgoff_t off; |
| 1758 | case SHMEM_HUGE_NEVER: |
| 1759 | goto alloc_nohuge; |
| 1760 | case SHMEM_HUGE_WITHIN_SIZE: |
| 1761 | off = round_up(index, HPAGE_PMD_NR); |
| 1762 | i_size = round_up(i_size_read(inode), PAGE_SIZE); |
| 1763 | if (i_size >= HPAGE_PMD_SIZE && |
| 1764 | i_size >> PAGE_SHIFT >= off) |
| 1765 | goto alloc_huge; |
| 1766 | /* fallthrough */ |
| 1767 | case SHMEM_HUGE_ADVISE: |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 1768 | if (sgp_huge == SGP_HUGE) |
| 1769 | goto alloc_huge; |
| 1770 | /* TODO: implement fadvise() hints */ |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1771 | goto alloc_nohuge; |
Hugh Dickins | 59a16ea | 2011-05-11 15:13:38 -0700 | [diff] [blame] | 1772 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1773 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1774 | alloc_huge: |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1775 | page = shmem_alloc_and_acct_page(gfp, inode, index, true); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1776 | if (IS_ERR(page)) { |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1777 | alloc_nohuge: page = shmem_alloc_and_acct_page(gfp, inode, |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1778 | index, false); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1779 | } |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1780 | if (IS_ERR(page)) { |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1781 | int retry = 5; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1782 | error = PTR_ERR(page); |
| 1783 | page = NULL; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1784 | if (error != -ENOSPC) |
| 1785 | goto failed; |
| 1786 | /* |
| 1787 | * Try to reclaim some spece by splitting a huge page |
| 1788 | * beyond i_size on the filesystem. |
| 1789 | */ |
| 1790 | while (retry--) { |
| 1791 | int ret; |
| 1792 | ret = shmem_unused_huge_shrink(sbinfo, NULL, 1); |
| 1793 | if (ret == SHRINK_STOP) |
| 1794 | break; |
| 1795 | if (ret) |
| 1796 | goto alloc_nohuge; |
| 1797 | } |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1798 | goto failed; |
| 1799 | } |
| 1800 | |
| 1801 | if (PageTransHuge(page)) |
| 1802 | hindex = round_down(index, HPAGE_PMD_NR); |
| 1803 | else |
| 1804 | hindex = index; |
| 1805 | |
Hugh Dickins | 66d2f4d | 2014-07-02 15:22:38 -0700 | [diff] [blame] | 1806 | if (sgp == SGP_WRITE) |
Hugh Dickins | eb39d61 | 2014-08-06 16:06:43 -0700 | [diff] [blame] | 1807 | __SetPageReferenced(page); |
Hugh Dickins | 66d2f4d | 2014-07-02 15:22:38 -0700 | [diff] [blame] | 1808 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1809 | error = mem_cgroup_try_charge(page, charge_mm, gfp, &memcg, |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1810 | PageTransHuge(page)); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1811 | if (error) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1812 | goto unacct; |
| 1813 | error = radix_tree_maybe_preload_order(gfp & GFP_RECLAIM_MASK, |
| 1814 | compound_order(page)); |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 1815 | if (!error) { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1816 | error = shmem_add_to_page_cache(page, mapping, hindex, |
Wang Sheng-Hui | fed400a | 2014-08-06 16:07:26 -0700 | [diff] [blame] | 1817 | NULL); |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 1818 | radix_tree_preload_end(); |
| 1819 | } |
| 1820 | if (error) { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1821 | mem_cgroup_cancel_charge(page, memcg, |
| 1822 | PageTransHuge(page)); |
| 1823 | goto unacct; |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 1824 | } |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1825 | mem_cgroup_commit_charge(page, memcg, false, |
| 1826 | PageTransHuge(page)); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1827 | lru_cache_add_anon(page); |
| 1828 | |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1829 | spin_lock_irq(&info->lock); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1830 | info->alloced += 1 << compound_order(page); |
| 1831 | inode->i_blocks += BLOCKS_PER_PAGE << compound_order(page); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1832 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1833 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1834 | alloced = true; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1835 | |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1836 | if (PageTransHuge(page) && |
| 1837 | DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE) < |
| 1838 | hindex + HPAGE_PMD_NR - 1) { |
| 1839 | /* |
| 1840 | * Part of the huge page is beyond i_size: subject |
| 1841 | * to shrink under memory pressure. |
| 1842 | */ |
| 1843 | spin_lock(&sbinfo->shrinklist_lock); |
Cong Wang | d041353 | 2017-08-10 15:24:24 -0700 | [diff] [blame] | 1844 | /* |
| 1845 | * _careful to defend against unlocked access to |
| 1846 | * ->shrink_list in shmem_unused_huge_shrink() |
| 1847 | */ |
| 1848 | if (list_empty_careful(&info->shrinklist)) { |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1849 | list_add_tail(&info->shrinklist, |
| 1850 | &sbinfo->shrinklist); |
| 1851 | sbinfo->shrinklist_len++; |
| 1852 | } |
| 1853 | spin_unlock(&sbinfo->shrinklist_lock); |
| 1854 | } |
| 1855 | |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1856 | /* |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1857 | * Let SGP_FALLOC use the SGP_WRITE optimization on a new page. |
| 1858 | */ |
| 1859 | if (sgp == SGP_FALLOC) |
| 1860 | sgp = SGP_WRITE; |
| 1861 | clear: |
| 1862 | /* |
| 1863 | * Let SGP_WRITE caller clear ends if write does not fill page; |
| 1864 | * but SGP_FALLOC on a page fallocated earlier must initialize |
| 1865 | * it now, lest undo on failure cancel our earlier guarantee. |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1866 | */ |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1867 | if (sgp != SGP_WRITE && !PageUptodate(page)) { |
| 1868 | struct page *head = compound_head(page); |
| 1869 | int i; |
| 1870 | |
| 1871 | for (i = 0; i < (1 << compound_order(head)); i++) { |
| 1872 | clear_highpage(head + i); |
| 1873 | flush_dcache_page(head + i); |
| 1874 | } |
| 1875 | SetPageUptodate(head); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1876 | } |
Hugh Dickins | 59a16ea | 2011-05-11 15:13:38 -0700 | [diff] [blame] | 1877 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1878 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1879 | /* Perhaps the file has been truncated since we checked */ |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1880 | if (sgp <= SGP_CACHE && |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1881 | ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) { |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1882 | if (alloced) { |
| 1883 | ClearPageDirty(page); |
| 1884 | delete_from_page_cache(page); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1885 | spin_lock_irq(&info->lock); |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1886 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1887 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1888 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1889 | error = -EINVAL; |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1890 | goto unlock; |
Shaohua Li | ff36b801 | 2010-08-09 17:19:06 -0700 | [diff] [blame] | 1891 | } |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1892 | *pagep = page + index - hindex; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1893 | return 0; |
Nick Piggin | d00806b | 2007-07-19 01:46:57 -0700 | [diff] [blame] | 1894 | |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1895 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1896 | * Error recovery. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1897 | */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1898 | unacct: |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1899 | shmem_inode_unacct_blocks(inode, 1 << compound_order(page)); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1900 | |
| 1901 | if (PageTransHuge(page)) { |
| 1902 | unlock_page(page); |
| 1903 | put_page(page); |
| 1904 | goto alloc_nohuge; |
| 1905 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1906 | failed: |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1907 | if (swap.val && !shmem_confirm_swap(mapping, index, swap)) |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1908 | error = -EEXIST; |
| 1909 | unlock: |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1910 | if (page) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1911 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1912 | put_page(page); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1913 | } |
| 1914 | if (error == -ENOSPC && !once++) { |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1915 | spin_lock_irq(&info->lock); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1916 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1917 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1918 | goto repeat; |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1919 | } |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1920 | if (error == -EEXIST) /* from above or from radix_tree_insert */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1921 | goto repeat; |
| 1922 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1923 | } |
| 1924 | |
Linus Torvalds | 10d20bd | 2016-12-05 12:10:29 -0800 | [diff] [blame] | 1925 | /* |
| 1926 | * This is like autoremove_wake_function, but it removes the wait queue |
| 1927 | * entry unconditionally - even if something else had already woken the |
| 1928 | * target. |
| 1929 | */ |
Ingo Molnar | ac6424b | 2017-06-20 12:06:13 +0200 | [diff] [blame] | 1930 | static int synchronous_wake_function(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) |
Linus Torvalds | 10d20bd | 2016-12-05 12:10:29 -0800 | [diff] [blame] | 1931 | { |
| 1932 | int ret = default_wake_function(wait, mode, sync, key); |
Ingo Molnar | 2055da9 | 2017-06-20 12:06:46 +0200 | [diff] [blame] | 1933 | list_del_init(&wait->entry); |
Linus Torvalds | 10d20bd | 2016-12-05 12:10:29 -0800 | [diff] [blame] | 1934 | return ret; |
| 1935 | } |
| 1936 | |
Dave Jiang | 11bac80 | 2017-02-24 14:56:41 -0800 | [diff] [blame] | 1937 | static int shmem_fault(struct vm_fault *vmf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1938 | { |
Dave Jiang | 11bac80 | 2017-02-24 14:56:41 -0800 | [diff] [blame] | 1939 | struct vm_area_struct *vma = vmf->vma; |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1940 | struct inode *inode = file_inode(vma->vm_file); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1941 | gfp_t gfp = mapping_gfp_mask(inode->i_mapping); |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 1942 | enum sgp_type sgp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1943 | int error; |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1944 | int ret = VM_FAULT_LOCKED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1945 | |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1946 | /* |
| 1947 | * Trinity finds that probing a hole which tmpfs is punching can |
| 1948 | * prevent the hole-punch from ever completing: which in turn |
| 1949 | * locks writers out with its hold on i_mutex. So refrain from |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1950 | * faulting pages into the hole while it's being punched. Although |
| 1951 | * shmem_undo_range() does remove the additions, it may be unable to |
| 1952 | * keep up, as each new page needs its own unmap_mapping_range() call, |
| 1953 | * and the i_mmap tree grows ever slower to scan if new vmas are added. |
| 1954 | * |
| 1955 | * It does not matter if we sometimes reach this check just before the |
| 1956 | * hole-punch begins, so that one fault then races with the punch: |
| 1957 | * we just need to make racing faults a rare case. |
| 1958 | * |
| 1959 | * The implementation below would be much simpler if we just used a |
| 1960 | * standard mutex or completion: but we cannot take i_mutex in fault, |
| 1961 | * and bloating every shmem inode for this unlikely case would be sad. |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1962 | */ |
| 1963 | if (unlikely(inode->i_private)) { |
| 1964 | struct shmem_falloc *shmem_falloc; |
| 1965 | |
| 1966 | spin_lock(&inode->i_lock); |
| 1967 | shmem_falloc = inode->i_private; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1968 | if (shmem_falloc && |
| 1969 | shmem_falloc->waitq && |
| 1970 | vmf->pgoff >= shmem_falloc->start && |
| 1971 | vmf->pgoff < shmem_falloc->next) { |
| 1972 | wait_queue_head_t *shmem_falloc_waitq; |
Linus Torvalds | 10d20bd | 2016-12-05 12:10:29 -0800 | [diff] [blame] | 1973 | DEFINE_WAIT_FUNC(shmem_fault_wait, synchronous_wake_function); |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1974 | |
| 1975 | ret = VM_FAULT_NOPAGE; |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1976 | if ((vmf->flags & FAULT_FLAG_ALLOW_RETRY) && |
| 1977 | !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) { |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1978 | /* It's polite to up mmap_sem if we can */ |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1979 | up_read(&vma->vm_mm->mmap_sem); |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1980 | ret = VM_FAULT_RETRY; |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1981 | } |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1982 | |
| 1983 | shmem_falloc_waitq = shmem_falloc->waitq; |
| 1984 | prepare_to_wait(shmem_falloc_waitq, &shmem_fault_wait, |
| 1985 | TASK_UNINTERRUPTIBLE); |
| 1986 | spin_unlock(&inode->i_lock); |
| 1987 | schedule(); |
| 1988 | |
| 1989 | /* |
| 1990 | * shmem_falloc_waitq points into the shmem_fallocate() |
| 1991 | * stack of the hole-punching task: shmem_falloc_waitq |
| 1992 | * is usually invalid by the time we reach here, but |
| 1993 | * finish_wait() does not dereference it in that case; |
| 1994 | * though i_lock needed lest racing with wake_up_all(). |
| 1995 | */ |
| 1996 | spin_lock(&inode->i_lock); |
| 1997 | finish_wait(shmem_falloc_waitq, &shmem_fault_wait); |
| 1998 | spin_unlock(&inode->i_lock); |
| 1999 | return ret; |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 2000 | } |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2001 | spin_unlock(&inode->i_lock); |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 2002 | } |
| 2003 | |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 2004 | sgp = SGP_CACHE; |
Michal Hocko | 1860033 | 2017-07-10 15:48:02 -0700 | [diff] [blame] | 2005 | |
| 2006 | if ((vma->vm_flags & VM_NOHUGEPAGE) || |
| 2007 | test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 2008 | sgp = SGP_NOHUGE; |
Michal Hocko | 1860033 | 2017-07-10 15:48:02 -0700 | [diff] [blame] | 2009 | else if (vma->vm_flags & VM_HUGEPAGE) |
| 2010 | sgp = SGP_HUGE; |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 2011 | |
| 2012 | error = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp, |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 2013 | gfp, vma, vmf, &ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2014 | if (error) |
| 2015 | return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 2016 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2017 | } |
| 2018 | |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 2019 | unsigned long shmem_get_unmapped_area(struct file *file, |
| 2020 | unsigned long uaddr, unsigned long len, |
| 2021 | unsigned long pgoff, unsigned long flags) |
| 2022 | { |
| 2023 | unsigned long (*get_area)(struct file *, |
| 2024 | unsigned long, unsigned long, unsigned long, unsigned long); |
| 2025 | unsigned long addr; |
| 2026 | unsigned long offset; |
| 2027 | unsigned long inflated_len; |
| 2028 | unsigned long inflated_addr; |
| 2029 | unsigned long inflated_offset; |
| 2030 | |
| 2031 | if (len > TASK_SIZE) |
| 2032 | return -ENOMEM; |
| 2033 | |
| 2034 | get_area = current->mm->get_unmapped_area; |
| 2035 | addr = get_area(file, uaddr, len, pgoff, flags); |
| 2036 | |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 2037 | if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 2038 | return addr; |
| 2039 | if (IS_ERR_VALUE(addr)) |
| 2040 | return addr; |
| 2041 | if (addr & ~PAGE_MASK) |
| 2042 | return addr; |
| 2043 | if (addr > TASK_SIZE - len) |
| 2044 | return addr; |
| 2045 | |
| 2046 | if (shmem_huge == SHMEM_HUGE_DENY) |
| 2047 | return addr; |
| 2048 | if (len < HPAGE_PMD_SIZE) |
| 2049 | return addr; |
| 2050 | if (flags & MAP_FIXED) |
| 2051 | return addr; |
| 2052 | /* |
| 2053 | * Our priority is to support MAP_SHARED mapped hugely; |
| 2054 | * and support MAP_PRIVATE mapped hugely too, until it is COWed. |
| 2055 | * But if caller specified an address hint, respect that as before. |
| 2056 | */ |
| 2057 | if (uaddr) |
| 2058 | return addr; |
| 2059 | |
| 2060 | if (shmem_huge != SHMEM_HUGE_FORCE) { |
| 2061 | struct super_block *sb; |
| 2062 | |
| 2063 | if (file) { |
| 2064 | VM_BUG_ON(file->f_op != &shmem_file_operations); |
| 2065 | sb = file_inode(file)->i_sb; |
| 2066 | } else { |
| 2067 | /* |
| 2068 | * Called directly from mm/mmap.c, or drivers/char/mem.c |
| 2069 | * for "/dev/zero", to create a shared anonymous object. |
| 2070 | */ |
| 2071 | if (IS_ERR(shm_mnt)) |
| 2072 | return addr; |
| 2073 | sb = shm_mnt->mnt_sb; |
| 2074 | } |
Toshi Kani | 3089bf6 | 2016-09-23 20:21:56 -0700 | [diff] [blame] | 2075 | if (SHMEM_SB(sb)->huge == SHMEM_HUGE_NEVER) |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 2076 | return addr; |
| 2077 | } |
| 2078 | |
| 2079 | offset = (pgoff << PAGE_SHIFT) & (HPAGE_PMD_SIZE-1); |
| 2080 | if (offset && offset + len < 2 * HPAGE_PMD_SIZE) |
| 2081 | return addr; |
| 2082 | if ((addr & (HPAGE_PMD_SIZE-1)) == offset) |
| 2083 | return addr; |
| 2084 | |
| 2085 | inflated_len = len + HPAGE_PMD_SIZE - PAGE_SIZE; |
| 2086 | if (inflated_len > TASK_SIZE) |
| 2087 | return addr; |
| 2088 | if (inflated_len < len) |
| 2089 | return addr; |
| 2090 | |
| 2091 | inflated_addr = get_area(NULL, 0, inflated_len, 0, flags); |
| 2092 | if (IS_ERR_VALUE(inflated_addr)) |
| 2093 | return addr; |
| 2094 | if (inflated_addr & ~PAGE_MASK) |
| 2095 | return addr; |
| 2096 | |
| 2097 | inflated_offset = inflated_addr & (HPAGE_PMD_SIZE-1); |
| 2098 | inflated_addr += offset - inflated_offset; |
| 2099 | if (inflated_offset > offset) |
| 2100 | inflated_addr += HPAGE_PMD_SIZE; |
| 2101 | |
| 2102 | if (inflated_addr > TASK_SIZE - len) |
| 2103 | return addr; |
| 2104 | return inflated_addr; |
| 2105 | } |
| 2106 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2107 | #ifdef CONFIG_NUMA |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2108 | static int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpol) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2109 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2110 | struct inode *inode = file_inode(vma->vm_file); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2111 | return mpol_set_shared_policy(&SHMEM_I(inode)->policy, vma, mpol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2112 | } |
| 2113 | |
Adrian Bunk | d8dc74f | 2007-10-16 01:26:26 -0700 | [diff] [blame] | 2114 | static struct mempolicy *shmem_get_policy(struct vm_area_struct *vma, |
| 2115 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2116 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2117 | struct inode *inode = file_inode(vma->vm_file); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2118 | pgoff_t index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2119 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2120 | index = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
| 2121 | return mpol_shared_policy_lookup(&SHMEM_I(inode)->policy, index); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2122 | } |
| 2123 | #endif |
| 2124 | |
| 2125 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 2126 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2127 | struct inode *inode = file_inode(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2128 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 2129 | int retval = -ENOMEM; |
| 2130 | |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 2131 | spin_lock_irq(&info->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2132 | if (lock && !(info->flags & VM_LOCKED)) { |
| 2133 | if (!user_shm_lock(inode->i_size, user)) |
| 2134 | goto out_nomem; |
| 2135 | info->flags |= VM_LOCKED; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 2136 | mapping_set_unevictable(file->f_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2137 | } |
| 2138 | if (!lock && (info->flags & VM_LOCKED) && user) { |
| 2139 | user_shm_unlock(inode->i_size, user); |
| 2140 | info->flags &= ~VM_LOCKED; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 2141 | mapping_clear_unevictable(file->f_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2142 | } |
| 2143 | retval = 0; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 2144 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2145 | out_nomem: |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 2146 | spin_unlock_irq(&info->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2147 | return retval; |
| 2148 | } |
| 2149 | |
Adrian Bunk | 9b83a6a | 2007-02-28 20:11:03 -0800 | [diff] [blame] | 2150 | static int shmem_mmap(struct file *file, struct vm_area_struct *vma) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2151 | { |
| 2152 | file_accessed(file); |
| 2153 | vma->vm_ops = &shmem_vm_ops; |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 2154 | if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE) && |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 2155 | ((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) < |
| 2156 | (vma->vm_end & HPAGE_PMD_MASK)) { |
| 2157 | khugepaged_enter(vma, vma->vm_flags); |
| 2158 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2159 | return 0; |
| 2160 | } |
| 2161 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2162 | static struct inode *shmem_get_inode(struct super_block *sb, const struct inode *dir, |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 2163 | umode_t mode, dev_t dev, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2164 | { |
| 2165 | struct inode *inode; |
| 2166 | struct shmem_inode_info *info; |
| 2167 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 2168 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2169 | if (shmem_reserve_inode(sb)) |
| 2170 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2171 | |
| 2172 | inode = new_inode(sb); |
| 2173 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 2174 | inode->i_ino = get_next_ino(); |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2175 | inode_init_owner(inode, dir, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2176 | inode->i_blocks = 0; |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 2177 | inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2178 | inode->i_generation = get_seconds(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2179 | info = SHMEM_I(inode); |
| 2180 | memset(info, 0, (char *)inode - (char *)info); |
| 2181 | spin_lock_init(&info->lock); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2182 | info->seals = F_SEAL_SEAL; |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 2183 | info->flags = flags & VM_NORESERVE; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 2184 | INIT_LIST_HEAD(&info->shrinklist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2185 | INIT_LIST_HEAD(&info->swaplist); |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2186 | simple_xattrs_init(&info->xattrs); |
Al Viro | 72c0490 | 2009-06-24 16:58:48 -0400 | [diff] [blame] | 2187 | cache_no_acl(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2188 | |
| 2189 | switch (mode & S_IFMT) { |
| 2190 | default: |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2191 | inode->i_op = &shmem_special_inode_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2192 | init_special_inode(inode, mode, dev); |
| 2193 | break; |
| 2194 | case S_IFREG: |
Hugh Dickins | 14fcc23 | 2008-07-28 15:46:19 -0700 | [diff] [blame] | 2195 | inode->i_mapping->a_ops = &shmem_aops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2196 | inode->i_op = &shmem_inode_operations; |
| 2197 | inode->i_fop = &shmem_file_operations; |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2198 | mpol_shared_policy_init(&info->policy, |
| 2199 | shmem_get_sbmpol(sbinfo)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2200 | break; |
| 2201 | case S_IFDIR: |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 2202 | inc_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2203 | /* Some things misbehave if size == 0 on a directory */ |
| 2204 | inode->i_size = 2 * BOGO_DIRENT_SIZE; |
| 2205 | inode->i_op = &shmem_dir_inode_operations; |
| 2206 | inode->i_fop = &simple_dir_operations; |
| 2207 | break; |
| 2208 | case S_IFLNK: |
| 2209 | /* |
| 2210 | * Must not load anything in the rbtree, |
| 2211 | * mpol_free_shared_policy will not be called. |
| 2212 | */ |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2213 | mpol_shared_policy_init(&info->policy, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2214 | break; |
| 2215 | } |
Joel Fernandes (Google) | 6447b34 | 2018-09-20 12:22:39 -0700 | [diff] [blame] | 2216 | |
| 2217 | lockdep_annotate_inode_mutex_key(inode); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2218 | } else |
| 2219 | shmem_free_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2220 | return inode; |
| 2221 | } |
| 2222 | |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 2223 | bool shmem_mapping(struct address_space *mapping) |
| 2224 | { |
Hugh Dickins | f800545 | 2017-02-22 15:41:42 -0800 | [diff] [blame] | 2225 | return mapping->a_ops == &shmem_aops; |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 2226 | } |
| 2227 | |
Mike Rapoport | 8d10396 | 2017-09-06 16:23:02 -0700 | [diff] [blame] | 2228 | static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, |
| 2229 | pmd_t *dst_pmd, |
| 2230 | struct vm_area_struct *dst_vma, |
| 2231 | unsigned long dst_addr, |
| 2232 | unsigned long src_addr, |
| 2233 | bool zeropage, |
| 2234 | struct page **pagep) |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2235 | { |
| 2236 | struct inode *inode = file_inode(dst_vma->vm_file); |
| 2237 | struct shmem_inode_info *info = SHMEM_I(inode); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2238 | struct address_space *mapping = inode->i_mapping; |
| 2239 | gfp_t gfp = mapping_gfp_mask(mapping); |
| 2240 | pgoff_t pgoff = linear_page_index(dst_vma, dst_addr); |
| 2241 | struct mem_cgroup *memcg; |
| 2242 | spinlock_t *ptl; |
| 2243 | void *page_kaddr; |
| 2244 | struct page *page; |
| 2245 | pte_t _dst_pte, *dst_pte; |
| 2246 | int ret; |
Andrea Arcangeli | af3edb3 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2247 | pgoff_t offset, max_off; |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2248 | |
Andrea Arcangeli | cb658a4 | 2017-02-22 15:43:55 -0800 | [diff] [blame] | 2249 | ret = -ENOMEM; |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 2250 | if (!shmem_inode_acct_block(inode, 1)) |
Andrea Arcangeli | cb658a4 | 2017-02-22 15:43:55 -0800 | [diff] [blame] | 2251 | goto out; |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2252 | |
Andrea Arcangeli | cb658a4 | 2017-02-22 15:43:55 -0800 | [diff] [blame] | 2253 | if (!*pagep) { |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2254 | page = shmem_alloc_page(gfp, info, pgoff); |
| 2255 | if (!page) |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 2256 | goto out_unacct_blocks; |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2257 | |
Mike Rapoport | 8d10396 | 2017-09-06 16:23:02 -0700 | [diff] [blame] | 2258 | if (!zeropage) { /* mcopy_atomic */ |
| 2259 | page_kaddr = kmap_atomic(page); |
| 2260 | ret = copy_from_user(page_kaddr, |
| 2261 | (const void __user *)src_addr, |
| 2262 | PAGE_SIZE); |
| 2263 | kunmap_atomic(page_kaddr); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2264 | |
Mike Rapoport | 8d10396 | 2017-09-06 16:23:02 -0700 | [diff] [blame] | 2265 | /* fallback to copy_from_user outside mmap_sem */ |
| 2266 | if (unlikely(ret)) { |
| 2267 | *pagep = page; |
| 2268 | shmem_inode_unacct_blocks(inode, 1); |
| 2269 | /* don't free the page */ |
Andrea Arcangeli | 82c5a8c | 2018-11-30 14:09:25 -0800 | [diff] [blame] | 2270 | return -ENOENT; |
Mike Rapoport | 8d10396 | 2017-09-06 16:23:02 -0700 | [diff] [blame] | 2271 | } |
| 2272 | } else { /* mfill_zeropage_atomic */ |
| 2273 | clear_highpage(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2274 | } |
| 2275 | } else { |
| 2276 | page = *pagep; |
| 2277 | *pagep = NULL; |
| 2278 | } |
| 2279 | |
Andrea Arcangeli | 9cc90c6 | 2017-02-22 15:43:49 -0800 | [diff] [blame] | 2280 | VM_BUG_ON(PageLocked(page) || PageSwapBacked(page)); |
| 2281 | __SetPageLocked(page); |
| 2282 | __SetPageSwapBacked(page); |
Andrea Arcangeli | a425d35 | 2017-02-22 15:43:52 -0800 | [diff] [blame] | 2283 | __SetPageUptodate(page); |
Andrea Arcangeli | 9cc90c6 | 2017-02-22 15:43:49 -0800 | [diff] [blame] | 2284 | |
Andrea Arcangeli | af3edb3 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2285 | ret = -EFAULT; |
| 2286 | offset = linear_page_index(dst_vma, dst_addr); |
| 2287 | max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); |
| 2288 | if (unlikely(offset >= max_off)) |
| 2289 | goto out_release; |
| 2290 | |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2291 | ret = mem_cgroup_try_charge(page, dst_mm, gfp, &memcg, false); |
| 2292 | if (ret) |
| 2293 | goto out_release; |
| 2294 | |
| 2295 | ret = radix_tree_maybe_preload(gfp & GFP_RECLAIM_MASK); |
| 2296 | if (!ret) { |
| 2297 | ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL); |
| 2298 | radix_tree_preload_end(); |
| 2299 | } |
| 2300 | if (ret) |
| 2301 | goto out_release_uncharge; |
| 2302 | |
| 2303 | mem_cgroup_commit_charge(page, memcg, false, false); |
| 2304 | |
| 2305 | _dst_pte = mk_pte(page, dst_vma->vm_page_prot); |
| 2306 | if (dst_vma->vm_flags & VM_WRITE) |
| 2307 | _dst_pte = pte_mkwrite(pte_mkdirty(_dst_pte)); |
Andrea Arcangeli | 46466e2 | 2018-11-30 14:09:43 -0800 | [diff] [blame] | 2308 | else { |
| 2309 | /* |
| 2310 | * We don't set the pte dirty if the vma has no |
| 2311 | * VM_WRITE permission, so mark the page dirty or it |
| 2312 | * could be freed from under us. We could do it |
| 2313 | * unconditionally before unlock_page(), but doing it |
| 2314 | * only if VM_WRITE is not set is faster. |
| 2315 | */ |
| 2316 | set_page_dirty(page); |
| 2317 | } |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2318 | |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2319 | dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl); |
Andrea Arcangeli | af3edb3 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2320 | |
| 2321 | ret = -EFAULT; |
| 2322 | max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); |
| 2323 | if (unlikely(offset >= max_off)) |
| 2324 | goto out_release_uncharge_unlock; |
| 2325 | |
| 2326 | ret = -EEXIST; |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2327 | if (!pte_none(*dst_pte)) |
| 2328 | goto out_release_uncharge_unlock; |
| 2329 | |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2330 | lru_cache_add_anon(page); |
| 2331 | |
| 2332 | spin_lock(&info->lock); |
| 2333 | info->alloced++; |
| 2334 | inode->i_blocks += BLOCKS_PER_PAGE; |
| 2335 | shmem_recalc_inode(inode); |
| 2336 | spin_unlock(&info->lock); |
| 2337 | |
| 2338 | inc_mm_counter(dst_mm, mm_counter_file(page)); |
| 2339 | page_add_file_rmap(page, false); |
| 2340 | set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); |
| 2341 | |
| 2342 | /* No need to invalidate - it was non-present before */ |
| 2343 | update_mmu_cache(dst_vma, dst_addr, dst_pte); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2344 | pte_unmap_unlock(dst_pte, ptl); |
Andrea Arcangeli | af3edb3 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2345 | unlock_page(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2346 | ret = 0; |
| 2347 | out: |
| 2348 | return ret; |
| 2349 | out_release_uncharge_unlock: |
| 2350 | pte_unmap_unlock(dst_pte, ptl); |
Andrea Arcangeli | 46466e2 | 2018-11-30 14:09:43 -0800 | [diff] [blame] | 2351 | ClearPageDirty(page); |
Andrea Arcangeli | af3edb3 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2352 | delete_from_page_cache(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2353 | out_release_uncharge: |
| 2354 | mem_cgroup_cancel_charge(page, memcg, false); |
| 2355 | out_release: |
Andrea Arcangeli | 9cc90c6 | 2017-02-22 15:43:49 -0800 | [diff] [blame] | 2356 | unlock_page(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2357 | put_page(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2358 | out_unacct_blocks: |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 2359 | shmem_inode_unacct_blocks(inode, 1); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2360 | goto out; |
| 2361 | } |
| 2362 | |
Mike Rapoport | 8d10396 | 2017-09-06 16:23:02 -0700 | [diff] [blame] | 2363 | int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, |
| 2364 | pmd_t *dst_pmd, |
| 2365 | struct vm_area_struct *dst_vma, |
| 2366 | unsigned long dst_addr, |
| 2367 | unsigned long src_addr, |
| 2368 | struct page **pagep) |
| 2369 | { |
| 2370 | return shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, |
| 2371 | dst_addr, src_addr, false, pagep); |
| 2372 | } |
| 2373 | |
| 2374 | int shmem_mfill_zeropage_pte(struct mm_struct *dst_mm, |
| 2375 | pmd_t *dst_pmd, |
| 2376 | struct vm_area_struct *dst_vma, |
| 2377 | unsigned long dst_addr) |
| 2378 | { |
| 2379 | struct page *page = NULL; |
| 2380 | |
| 2381 | return shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, |
| 2382 | dst_addr, 0, true, &page); |
| 2383 | } |
| 2384 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2385 | #ifdef CONFIG_TMPFS |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2386 | static const struct inode_operations shmem_symlink_inode_operations; |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2387 | static const struct inode_operations shmem_short_symlink_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2388 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2389 | #ifdef CONFIG_TMPFS_XATTR |
| 2390 | static int shmem_initxattrs(struct inode *, const struct xattr *, void *); |
| 2391 | #else |
| 2392 | #define shmem_initxattrs NULL |
| 2393 | #endif |
| 2394 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2395 | static int |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2396 | shmem_write_begin(struct file *file, struct address_space *mapping, |
| 2397 | loff_t pos, unsigned len, unsigned flags, |
| 2398 | struct page **pagep, void **fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2399 | { |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2400 | struct inode *inode = mapping->host; |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2401 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2402 | pgoff_t index = pos >> PAGE_SHIFT; |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2403 | |
| 2404 | /* i_mutex is held by caller */ |
Steven Rostedt (VMware) | 3f472cc | 2017-02-24 14:59:10 -0800 | [diff] [blame] | 2405 | if (unlikely(info->seals & (F_SEAL_WRITE | F_SEAL_GROW))) { |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2406 | if (info->seals & F_SEAL_WRITE) |
| 2407 | return -EPERM; |
| 2408 | if ((info->seals & F_SEAL_GROW) && pos + len > inode->i_size) |
| 2409 | return -EPERM; |
| 2410 | } |
| 2411 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 2412 | return shmem_getpage(inode, index, pagep, SGP_WRITE); |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2413 | } |
| 2414 | |
| 2415 | static int |
| 2416 | shmem_write_end(struct file *file, struct address_space *mapping, |
| 2417 | loff_t pos, unsigned len, unsigned copied, |
| 2418 | struct page *page, void *fsdata) |
| 2419 | { |
| 2420 | struct inode *inode = mapping->host; |
| 2421 | |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2422 | if (pos + copied > inode->i_size) |
| 2423 | i_size_write(inode, pos + copied); |
| 2424 | |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2425 | if (!PageUptodate(page)) { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 2426 | struct page *head = compound_head(page); |
| 2427 | if (PageTransCompound(page)) { |
| 2428 | int i; |
| 2429 | |
| 2430 | for (i = 0; i < HPAGE_PMD_NR; i++) { |
| 2431 | if (head + i == page) |
| 2432 | continue; |
| 2433 | clear_highpage(head + i); |
| 2434 | flush_dcache_page(head + i); |
| 2435 | } |
| 2436 | } |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2437 | if (copied < PAGE_SIZE) { |
| 2438 | unsigned from = pos & (PAGE_SIZE - 1); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2439 | zero_user_segments(page, 0, from, |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2440 | from + copied, PAGE_SIZE); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2441 | } |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 2442 | SetPageUptodate(head); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2443 | } |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2444 | set_page_dirty(page); |
Wu Fengguang | 6746aff | 2009-09-16 11:50:14 +0200 | [diff] [blame] | 2445 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2446 | put_page(page); |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2447 | |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2448 | return copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2449 | } |
| 2450 | |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 2451 | static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2452 | { |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2453 | struct file *file = iocb->ki_filp; |
| 2454 | struct inode *inode = file_inode(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2455 | struct address_space *mapping = inode->i_mapping; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2456 | pgoff_t index; |
| 2457 | unsigned long offset; |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 2458 | enum sgp_type sgp = SGP_READ; |
Geert Uytterhoeven | f7c1d07 | 2014-04-13 20:46:22 +0200 | [diff] [blame] | 2459 | int error = 0; |
Al Viro | cb66a7a | 2014-03-04 15:24:06 -0500 | [diff] [blame] | 2460 | ssize_t retval = 0; |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2461 | loff_t *ppos = &iocb->ki_pos; |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 2462 | |
| 2463 | /* |
| 2464 | * Might this read be for a stacking filesystem? Then when reading |
| 2465 | * holes of a sparse file, we actually need to allocate those pages, |
| 2466 | * and even mark them dirty, so it cannot exceed the max_blocks limit. |
| 2467 | */ |
Al Viro | 777eda2 | 2014-12-17 04:46:46 -0500 | [diff] [blame] | 2468 | if (!iter_is_iovec(to)) |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 2469 | sgp = SGP_CACHE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2470 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2471 | index = *ppos >> PAGE_SHIFT; |
| 2472 | offset = *ppos & ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2473 | |
| 2474 | for (;;) { |
| 2475 | struct page *page = NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2476 | pgoff_t end_index; |
| 2477 | unsigned long nr, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2478 | loff_t i_size = i_size_read(inode); |
| 2479 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2480 | end_index = i_size >> PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2481 | if (index > end_index) |
| 2482 | break; |
| 2483 | if (index == end_index) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2484 | nr = i_size & ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2485 | if (nr <= offset) |
| 2486 | break; |
| 2487 | } |
| 2488 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 2489 | error = shmem_getpage(inode, index, &page, sgp); |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2490 | if (error) { |
| 2491 | if (error == -EINVAL) |
| 2492 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2493 | break; |
| 2494 | } |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 2495 | if (page) { |
| 2496 | if (sgp == SGP_CACHE) |
| 2497 | set_page_dirty(page); |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2498 | unlock_page(page); |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 2499 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2500 | |
| 2501 | /* |
| 2502 | * We must evaluate after, since reads (unlike writes) |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2503 | * are called without i_mutex protection against truncate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2504 | */ |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2505 | nr = PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2506 | i_size = i_size_read(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2507 | end_index = i_size >> PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2508 | if (index == end_index) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2509 | nr = i_size & ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2510 | if (nr <= offset) { |
| 2511 | if (page) |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2512 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2513 | break; |
| 2514 | } |
| 2515 | } |
| 2516 | nr -= offset; |
| 2517 | |
| 2518 | if (page) { |
| 2519 | /* |
| 2520 | * If users can be writing to this page using arbitrary |
| 2521 | * virtual addresses, take care about potential aliasing |
| 2522 | * before reading the page on the kernel side. |
| 2523 | */ |
| 2524 | if (mapping_writably_mapped(mapping)) |
| 2525 | flush_dcache_page(page); |
| 2526 | /* |
| 2527 | * Mark the page accessed if we read the beginning. |
| 2528 | */ |
| 2529 | if (!offset) |
| 2530 | mark_page_accessed(page); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 2531 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2532 | page = ZERO_PAGE(0); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2533 | get_page(page); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 2534 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2535 | |
| 2536 | /* |
| 2537 | * Ok, we have the page, and it's up-to-date, so |
| 2538 | * now we can copy it to user space... |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2539 | */ |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 2540 | ret = copy_page_to_iter(page, offset, nr, to); |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2541 | retval += ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2542 | offset += ret; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2543 | index += offset >> PAGE_SHIFT; |
| 2544 | offset &= ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2545 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2546 | put_page(page); |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 2547 | if (!iov_iter_count(to)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2548 | break; |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2549 | if (ret < nr) { |
| 2550 | error = -EFAULT; |
| 2551 | break; |
| 2552 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2553 | cond_resched(); |
| 2554 | } |
| 2555 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2556 | *ppos = ((loff_t) index << PAGE_SHIFT) + offset; |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2557 | file_accessed(file); |
| 2558 | return retval ? retval : error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2559 | } |
| 2560 | |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2561 | /* |
| 2562 | * llseek SEEK_DATA or SEEK_HOLE through the radix_tree. |
| 2563 | */ |
| 2564 | static pgoff_t shmem_seek_hole_data(struct address_space *mapping, |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2565 | pgoff_t index, pgoff_t end, int whence) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2566 | { |
| 2567 | struct page *page; |
| 2568 | struct pagevec pvec; |
| 2569 | pgoff_t indices[PAGEVEC_SIZE]; |
| 2570 | bool done = false; |
| 2571 | int i; |
| 2572 | |
| 2573 | pagevec_init(&pvec, 0); |
| 2574 | pvec.nr = 1; /* start small: we may be there already */ |
| 2575 | while (!done) { |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 2576 | pvec.nr = find_get_entries(mapping, index, |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2577 | pvec.nr, pvec.pages, indices); |
| 2578 | if (!pvec.nr) { |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2579 | if (whence == SEEK_DATA) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2580 | index = end; |
| 2581 | break; |
| 2582 | } |
| 2583 | for (i = 0; i < pvec.nr; i++, index++) { |
| 2584 | if (index < indices[i]) { |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2585 | if (whence == SEEK_HOLE) { |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2586 | done = true; |
| 2587 | break; |
| 2588 | } |
| 2589 | index = indices[i]; |
| 2590 | } |
| 2591 | page = pvec.pages[i]; |
| 2592 | if (page && !radix_tree_exceptional_entry(page)) { |
| 2593 | if (!PageUptodate(page)) |
| 2594 | page = NULL; |
| 2595 | } |
| 2596 | if (index >= end || |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2597 | (page && whence == SEEK_DATA) || |
| 2598 | (!page && whence == SEEK_HOLE)) { |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2599 | done = true; |
| 2600 | break; |
| 2601 | } |
| 2602 | } |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 2603 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2604 | pagevec_release(&pvec); |
| 2605 | pvec.nr = PAGEVEC_SIZE; |
| 2606 | cond_resched(); |
| 2607 | } |
| 2608 | return index; |
| 2609 | } |
| 2610 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2611 | static loff_t shmem_file_llseek(struct file *file, loff_t offset, int whence) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2612 | { |
| 2613 | struct address_space *mapping = file->f_mapping; |
| 2614 | struct inode *inode = mapping->host; |
| 2615 | pgoff_t start, end; |
| 2616 | loff_t new_offset; |
| 2617 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2618 | if (whence != SEEK_DATA && whence != SEEK_HOLE) |
| 2619 | return generic_file_llseek_size(file, offset, whence, |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2620 | MAX_LFS_FILESIZE, i_size_read(inode)); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2621 | inode_lock(inode); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2622 | /* We're holding i_mutex so we can access i_size directly */ |
| 2623 | |
Yufen Yu | a84c872 | 2018-11-16 15:08:39 -0800 | [diff] [blame] | 2624 | if (offset < 0 || offset >= inode->i_size) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2625 | offset = -ENXIO; |
| 2626 | else { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2627 | start = offset >> PAGE_SHIFT; |
| 2628 | end = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2629 | new_offset = shmem_seek_hole_data(mapping, start, end, whence); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2630 | new_offset <<= PAGE_SHIFT; |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2631 | if (new_offset > offset) { |
| 2632 | if (new_offset < inode->i_size) |
| 2633 | offset = new_offset; |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2634 | else if (whence == SEEK_DATA) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2635 | offset = -ENXIO; |
| 2636 | else |
| 2637 | offset = inode->i_size; |
| 2638 | } |
| 2639 | } |
| 2640 | |
Hugh Dickins | 387aae6 | 2013-08-04 11:30:25 -0700 | [diff] [blame] | 2641 | if (offset >= 0) |
| 2642 | offset = vfs_setpos(file, offset, MAX_LFS_FILESIZE); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2643 | inode_unlock(inode); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2644 | return offset; |
| 2645 | } |
| 2646 | |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2647 | /* |
| 2648 | * We need a tag: a new tag would expand every radix_tree_node by 8 bytes, |
| 2649 | * so reuse a tag which we firmly believe is never set or cleared on shmem. |
| 2650 | */ |
| 2651 | #define SHMEM_TAG_PINNED PAGECACHE_TAG_TOWRITE |
| 2652 | #define LAST_SCAN 4 /* about 150ms max */ |
| 2653 | |
| 2654 | static void shmem_tag_pins(struct address_space *mapping) |
| 2655 | { |
| 2656 | struct radix_tree_iter iter; |
| 2657 | void **slot; |
| 2658 | pgoff_t start; |
| 2659 | struct page *page; |
Matthew Wilcox (Oracle) | 391d4ee | 2019-10-25 09:58:35 -0700 | [diff] [blame] | 2660 | unsigned int tagged = 0; |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2661 | |
| 2662 | lru_add_drain(); |
| 2663 | start = 0; |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2664 | |
Matthew Wilcox (Oracle) | 391d4ee | 2019-10-25 09:58:35 -0700 | [diff] [blame] | 2665 | spin_lock_irq(&mapping->tree_lock); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2666 | radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) { |
zhong jiang | 988f701 | 2019-11-18 11:26:07 +0800 | [diff] [blame] | 2667 | page = radix_tree_deref_slot_protected(slot, &mapping->tree_lock); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2668 | if (!page || radix_tree_exception(page)) { |
Matthew Wilcox | 2cf938a | 2016-03-17 14:22:03 -0700 | [diff] [blame] | 2669 | if (radix_tree_deref_retry(page)) { |
| 2670 | slot = radix_tree_iter_retry(&iter); |
| 2671 | continue; |
| 2672 | } |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2673 | } else if (page_count(page) - page_mapcount(page) > 1) { |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2674 | radix_tree_tag_set(&mapping->page_tree, iter.index, |
| 2675 | SHMEM_TAG_PINNED); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2676 | } |
| 2677 | |
Matthew Wilcox (Oracle) | 391d4ee | 2019-10-25 09:58:35 -0700 | [diff] [blame] | 2678 | if (++tagged % 1024) |
| 2679 | continue; |
| 2680 | |
| 2681 | slot = radix_tree_iter_resume(slot, &iter); |
| 2682 | spin_unlock_irq(&mapping->tree_lock); |
| 2683 | cond_resched(); |
| 2684 | spin_lock_irq(&mapping->tree_lock); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2685 | } |
Matthew Wilcox (Oracle) | 391d4ee | 2019-10-25 09:58:35 -0700 | [diff] [blame] | 2686 | spin_unlock_irq(&mapping->tree_lock); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2687 | } |
| 2688 | |
| 2689 | /* |
| 2690 | * Setting SEAL_WRITE requires us to verify there's no pending writer. However, |
| 2691 | * via get_user_pages(), drivers might have some pending I/O without any active |
| 2692 | * user-space mappings (eg., direct-IO, AIO). Therefore, we look at all pages |
| 2693 | * and see whether it has an elevated ref-count. If so, we tag them and wait for |
| 2694 | * them to be dropped. |
| 2695 | * The caller must guarantee that no new user will acquire writable references |
| 2696 | * to those pages to avoid races. |
| 2697 | */ |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2698 | static int shmem_wait_for_pins(struct address_space *mapping) |
| 2699 | { |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2700 | struct radix_tree_iter iter; |
| 2701 | void **slot; |
| 2702 | pgoff_t start; |
| 2703 | struct page *page; |
| 2704 | int error, scan; |
| 2705 | |
| 2706 | shmem_tag_pins(mapping); |
| 2707 | |
| 2708 | error = 0; |
| 2709 | for (scan = 0; scan <= LAST_SCAN; scan++) { |
| 2710 | if (!radix_tree_tagged(&mapping->page_tree, SHMEM_TAG_PINNED)) |
| 2711 | break; |
| 2712 | |
| 2713 | if (!scan) |
| 2714 | lru_add_drain_all(); |
| 2715 | else if (schedule_timeout_killable((HZ << scan) / 200)) |
| 2716 | scan = LAST_SCAN; |
| 2717 | |
| 2718 | start = 0; |
| 2719 | rcu_read_lock(); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2720 | radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter, |
| 2721 | start, SHMEM_TAG_PINNED) { |
| 2722 | |
| 2723 | page = radix_tree_deref_slot(slot); |
| 2724 | if (radix_tree_exception(page)) { |
Matthew Wilcox | 2cf938a | 2016-03-17 14:22:03 -0700 | [diff] [blame] | 2725 | if (radix_tree_deref_retry(page)) { |
| 2726 | slot = radix_tree_iter_retry(&iter); |
| 2727 | continue; |
| 2728 | } |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2729 | |
| 2730 | page = NULL; |
| 2731 | } |
| 2732 | |
| 2733 | if (page && |
| 2734 | page_count(page) - page_mapcount(page) != 1) { |
| 2735 | if (scan < LAST_SCAN) |
| 2736 | goto continue_resched; |
| 2737 | |
| 2738 | /* |
| 2739 | * On the last scan, we clean up all those tags |
| 2740 | * we inserted; but make a note that we still |
| 2741 | * found pages pinned. |
| 2742 | */ |
| 2743 | error = -EBUSY; |
| 2744 | } |
| 2745 | |
| 2746 | spin_lock_irq(&mapping->tree_lock); |
| 2747 | radix_tree_tag_clear(&mapping->page_tree, |
| 2748 | iter.index, SHMEM_TAG_PINNED); |
| 2749 | spin_unlock_irq(&mapping->tree_lock); |
| 2750 | continue_resched: |
| 2751 | if (need_resched()) { |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 2752 | slot = radix_tree_iter_resume(slot, &iter); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2753 | cond_resched_rcu(); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2754 | } |
| 2755 | } |
| 2756 | rcu_read_unlock(); |
| 2757 | } |
| 2758 | |
| 2759 | return error; |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2760 | } |
| 2761 | |
| 2762 | #define F_ALL_SEALS (F_SEAL_SEAL | \ |
| 2763 | F_SEAL_SHRINK | \ |
| 2764 | F_SEAL_GROW | \ |
| 2765 | F_SEAL_WRITE) |
| 2766 | |
| 2767 | int shmem_add_seals(struct file *file, unsigned int seals) |
| 2768 | { |
| 2769 | struct inode *inode = file_inode(file); |
| 2770 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 2771 | int error; |
| 2772 | |
| 2773 | /* |
| 2774 | * SEALING |
| 2775 | * Sealing allows multiple parties to share a shmem-file but restrict |
| 2776 | * access to a specific subset of file operations. Seals can only be |
| 2777 | * added, but never removed. This way, mutually untrusted parties can |
| 2778 | * share common memory regions with a well-defined policy. A malicious |
| 2779 | * peer can thus never perform unwanted operations on a shared object. |
| 2780 | * |
| 2781 | * Seals are only supported on special shmem-files and always affect |
| 2782 | * the whole underlying inode. Once a seal is set, it may prevent some |
| 2783 | * kinds of access to the file. Currently, the following seals are |
| 2784 | * defined: |
| 2785 | * SEAL_SEAL: Prevent further seals from being set on this file |
| 2786 | * SEAL_SHRINK: Prevent the file from shrinking |
| 2787 | * SEAL_GROW: Prevent the file from growing |
| 2788 | * SEAL_WRITE: Prevent write access to the file |
| 2789 | * |
| 2790 | * As we don't require any trust relationship between two parties, we |
| 2791 | * must prevent seals from being removed. Therefore, sealing a file |
| 2792 | * only adds a given set of seals to the file, it never touches |
| 2793 | * existing seals. Furthermore, the "setting seals"-operation can be |
| 2794 | * sealed itself, which basically prevents any further seal from being |
| 2795 | * added. |
| 2796 | * |
| 2797 | * Semantics of sealing are only defined on volatile files. Only |
| 2798 | * anonymous shmem files support sealing. More importantly, seals are |
| 2799 | * never written to disk. Therefore, there's no plan to support it on |
| 2800 | * other file types. |
| 2801 | */ |
| 2802 | |
| 2803 | if (file->f_op != &shmem_file_operations) |
| 2804 | return -EINVAL; |
| 2805 | if (!(file->f_mode & FMODE_WRITE)) |
| 2806 | return -EPERM; |
| 2807 | if (seals & ~(unsigned int)F_ALL_SEALS) |
| 2808 | return -EINVAL; |
| 2809 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2810 | inode_lock(inode); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2811 | |
| 2812 | if (info->seals & F_SEAL_SEAL) { |
| 2813 | error = -EPERM; |
| 2814 | goto unlock; |
| 2815 | } |
| 2816 | |
| 2817 | if ((seals & F_SEAL_WRITE) && !(info->seals & F_SEAL_WRITE)) { |
| 2818 | error = mapping_deny_writable(file->f_mapping); |
| 2819 | if (error) |
| 2820 | goto unlock; |
| 2821 | |
| 2822 | error = shmem_wait_for_pins(file->f_mapping); |
| 2823 | if (error) { |
| 2824 | mapping_allow_writable(file->f_mapping); |
| 2825 | goto unlock; |
| 2826 | } |
| 2827 | } |
| 2828 | |
| 2829 | info->seals |= seals; |
| 2830 | error = 0; |
| 2831 | |
| 2832 | unlock: |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2833 | inode_unlock(inode); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2834 | return error; |
| 2835 | } |
| 2836 | EXPORT_SYMBOL_GPL(shmem_add_seals); |
| 2837 | |
| 2838 | int shmem_get_seals(struct file *file) |
| 2839 | { |
| 2840 | if (file->f_op != &shmem_file_operations) |
| 2841 | return -EINVAL; |
| 2842 | |
| 2843 | return SHMEM_I(file_inode(file))->seals; |
| 2844 | } |
| 2845 | EXPORT_SYMBOL_GPL(shmem_get_seals); |
| 2846 | |
| 2847 | long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg) |
| 2848 | { |
| 2849 | long error; |
| 2850 | |
| 2851 | switch (cmd) { |
| 2852 | case F_ADD_SEALS: |
| 2853 | /* disallow upper 32bit */ |
| 2854 | if (arg > UINT_MAX) |
| 2855 | return -EINVAL; |
| 2856 | |
| 2857 | error = shmem_add_seals(file, arg); |
| 2858 | break; |
| 2859 | case F_GET_SEALS: |
| 2860 | error = shmem_get_seals(file); |
| 2861 | break; |
| 2862 | default: |
| 2863 | error = -EINVAL; |
| 2864 | break; |
| 2865 | } |
| 2866 | |
| 2867 | return error; |
| 2868 | } |
| 2869 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2870 | static long shmem_fallocate(struct file *file, int mode, loff_t offset, |
| 2871 | loff_t len) |
| 2872 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2873 | struct inode *inode = file_inode(file); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2874 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2875 | struct shmem_inode_info *info = SHMEM_I(inode); |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2876 | struct shmem_falloc shmem_falloc; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2877 | pgoff_t start, index, end; |
| 2878 | int error; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2879 | |
Hugh Dickins | 13ace4d | 2014-06-23 13:22:03 -0700 | [diff] [blame] | 2880 | if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) |
| 2881 | return -EOPNOTSUPP; |
| 2882 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2883 | inode_lock(inode); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2884 | |
| 2885 | if (mode & FALLOC_FL_PUNCH_HOLE) { |
| 2886 | struct address_space *mapping = file->f_mapping; |
| 2887 | loff_t unmap_start = round_up(offset, PAGE_SIZE); |
| 2888 | loff_t unmap_end = round_down(offset + len, PAGE_SIZE) - 1; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2889 | DECLARE_WAIT_QUEUE_HEAD_ONSTACK(shmem_falloc_waitq); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2890 | |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2891 | /* protected by i_mutex */ |
| 2892 | if (info->seals & F_SEAL_WRITE) { |
| 2893 | error = -EPERM; |
| 2894 | goto out; |
| 2895 | } |
| 2896 | |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2897 | shmem_falloc.waitq = &shmem_falloc_waitq; |
Chen Jun | f49aa24 | 2019-11-30 17:58:11 -0800 | [diff] [blame] | 2898 | shmem_falloc.start = (u64)unmap_start >> PAGE_SHIFT; |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 2899 | shmem_falloc.next = (unmap_end + 1) >> PAGE_SHIFT; |
| 2900 | spin_lock(&inode->i_lock); |
| 2901 | inode->i_private = &shmem_falloc; |
| 2902 | spin_unlock(&inode->i_lock); |
| 2903 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2904 | if ((u64)unmap_end > (u64)unmap_start) |
| 2905 | unmap_mapping_range(mapping, unmap_start, |
| 2906 | 1 + unmap_end - unmap_start, 0); |
| 2907 | shmem_truncate_range(inode, offset, offset + len - 1); |
| 2908 | /* No need to unmap again: hole-punching leaves COWed pages */ |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2909 | |
| 2910 | spin_lock(&inode->i_lock); |
| 2911 | inode->i_private = NULL; |
| 2912 | wake_up_all(&shmem_falloc_waitq); |
Ingo Molnar | 2055da9 | 2017-06-20 12:06:46 +0200 | [diff] [blame] | 2913 | WARN_ON_ONCE(!list_empty(&shmem_falloc_waitq.head)); |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2914 | spin_unlock(&inode->i_lock); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2915 | error = 0; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2916 | goto out; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2917 | } |
| 2918 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2919 | /* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */ |
| 2920 | error = inode_newsize_ok(inode, offset + len); |
| 2921 | if (error) |
| 2922 | goto out; |
| 2923 | |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2924 | if ((info->seals & F_SEAL_GROW) && offset + len > inode->i_size) { |
| 2925 | error = -EPERM; |
| 2926 | goto out; |
| 2927 | } |
| 2928 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2929 | start = offset >> PAGE_SHIFT; |
| 2930 | end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2931 | /* Try to avoid a swapstorm if len is impossible to satisfy */ |
| 2932 | if (sbinfo->max_blocks && end - start > sbinfo->max_blocks) { |
| 2933 | error = -ENOSPC; |
| 2934 | goto out; |
| 2935 | } |
| 2936 | |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2937 | shmem_falloc.waitq = NULL; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2938 | shmem_falloc.start = start; |
| 2939 | shmem_falloc.next = start; |
| 2940 | shmem_falloc.nr_falloced = 0; |
| 2941 | shmem_falloc.nr_unswapped = 0; |
| 2942 | spin_lock(&inode->i_lock); |
| 2943 | inode->i_private = &shmem_falloc; |
| 2944 | spin_unlock(&inode->i_lock); |
| 2945 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2946 | for (index = start; index < end; index++) { |
| 2947 | struct page *page; |
| 2948 | |
| 2949 | /* |
| 2950 | * Good, the fallocate(2) manpage permits EINTR: we may have |
| 2951 | * been interrupted because we are using up too much memory. |
| 2952 | */ |
| 2953 | if (signal_pending(current)) |
| 2954 | error = -EINTR; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2955 | else if (shmem_falloc.nr_unswapped > shmem_falloc.nr_falloced) |
| 2956 | error = -ENOMEM; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2957 | else |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 2958 | error = shmem_getpage(inode, index, &page, SGP_FALLOC); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2959 | if (error) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2960 | /* Remove the !PageUptodate pages we added */ |
Hugh Dickins | 7f55656 | 2016-07-10 16:46:32 -0700 | [diff] [blame] | 2961 | if (index > start) { |
| 2962 | shmem_undo_range(inode, |
| 2963 | (loff_t)start << PAGE_SHIFT, |
| 2964 | ((loff_t)index << PAGE_SHIFT) - 1, true); |
| 2965 | } |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2966 | goto undone; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2967 | } |
| 2968 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2969 | /* |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2970 | * Inform shmem_writepage() how far we have reached. |
| 2971 | * No need for lock or barrier: we have the page lock. |
| 2972 | */ |
| 2973 | shmem_falloc.next++; |
| 2974 | if (!PageUptodate(page)) |
| 2975 | shmem_falloc.nr_falloced++; |
| 2976 | |
| 2977 | /* |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2978 | * If !PageUptodate, leave it that way so that freeable pages |
| 2979 | * can be recognized if we need to rollback on error later. |
| 2980 | * But set_page_dirty so that memory pressure will swap rather |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2981 | * than free the pages we are allocating (and SGP_CACHE pages |
| 2982 | * might still be clean: we now need to mark those dirty too). |
| 2983 | */ |
| 2984 | set_page_dirty(page); |
| 2985 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2986 | put_page(page); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2987 | cond_resched(); |
| 2988 | } |
| 2989 | |
| 2990 | if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) |
| 2991 | i_size_write(inode, offset + len); |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 2992 | inode->i_ctime = current_time(inode); |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2993 | undone: |
| 2994 | spin_lock(&inode->i_lock); |
| 2995 | inode->i_private = NULL; |
| 2996 | spin_unlock(&inode->i_lock); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2997 | out: |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2998 | inode_unlock(inode); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2999 | return error; |
| 3000 | } |
| 3001 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 3002 | static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3003 | { |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 3004 | struct shmem_sb_info *sbinfo = SHMEM_SB(dentry->d_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3005 | |
| 3006 | buf->f_type = TMPFS_MAGIC; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3007 | buf->f_bsize = PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3008 | buf->f_namelen = NAME_MAX; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3009 | if (sbinfo->max_blocks) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3010 | buf->f_blocks = sbinfo->max_blocks; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3011 | buf->f_bavail = |
| 3012 | buf->f_bfree = sbinfo->max_blocks - |
| 3013 | percpu_counter_sum(&sbinfo->used_blocks); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3014 | } |
| 3015 | if (sbinfo->max_inodes) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3016 | buf->f_files = sbinfo->max_inodes; |
| 3017 | buf->f_ffree = sbinfo->free_inodes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3018 | } |
| 3019 | /* else leave those fields 0 like simple_statfs */ |
| 3020 | return 0; |
| 3021 | } |
| 3022 | |
| 3023 | /* |
| 3024 | * File creation. Allocate an inode, and we're done.. |
| 3025 | */ |
| 3026 | static int |
Al Viro | 1a67aaf | 2011-07-26 01:52:52 -0400 | [diff] [blame] | 3027 | shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3028 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 3029 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3030 | int error = -ENOSPC; |
| 3031 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 3032 | inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3033 | if (inode) { |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3034 | error = simple_acl_create(dir, inode); |
| 3035 | if (error) |
| 3036 | goto out_iput; |
Eric Paris | 2a7dba3 | 2011-02-01 11:05:39 -0500 | [diff] [blame] | 3037 | error = security_inode_init_security(inode, dir, |
Mimi Zohar | 9d8f13b | 2011-06-06 15:29:25 -0400 | [diff] [blame] | 3038 | &dentry->d_name, |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3039 | shmem_initxattrs, NULL); |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3040 | if (error && error != -EOPNOTSUPP) |
| 3041 | goto out_iput; |
Mimi Zohar | 37ec43c | 2013-04-14 09:21:47 -0400 | [diff] [blame] | 3042 | |
Al Viro | 718deb6 | 2009-12-16 19:35:36 -0500 | [diff] [blame] | 3043 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3044 | dir->i_size += BOGO_DIRENT_SIZE; |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3045 | dir->i_ctime = dir->i_mtime = current_time(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3046 | d_instantiate(dentry, inode); |
| 3047 | dget(dentry); /* Extra count - pin the dentry in core */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3048 | } |
| 3049 | return error; |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3050 | out_iput: |
| 3051 | iput(inode); |
| 3052 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3053 | } |
| 3054 | |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 3055 | static int |
| 3056 | shmem_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) |
| 3057 | { |
| 3058 | struct inode *inode; |
| 3059 | int error = -ENOSPC; |
| 3060 | |
| 3061 | inode = shmem_get_inode(dir->i_sb, dir, mode, 0, VM_NORESERVE); |
| 3062 | if (inode) { |
| 3063 | error = security_inode_init_security(inode, dir, |
| 3064 | NULL, |
| 3065 | shmem_initxattrs, NULL); |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3066 | if (error && error != -EOPNOTSUPP) |
| 3067 | goto out_iput; |
| 3068 | error = simple_acl_create(dir, inode); |
| 3069 | if (error) |
| 3070 | goto out_iput; |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 3071 | d_tmpfile(dentry, inode); |
| 3072 | } |
| 3073 | return error; |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3074 | out_iput: |
| 3075 | iput(inode); |
| 3076 | return error; |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 3077 | } |
| 3078 | |
Al Viro | 18bb1db | 2011-07-26 01:41:39 -0400 | [diff] [blame] | 3079 | static int shmem_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3080 | { |
| 3081 | int error; |
| 3082 | |
| 3083 | if ((error = shmem_mknod(dir, dentry, mode | S_IFDIR, 0))) |
| 3084 | return error; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 3085 | inc_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3086 | return 0; |
| 3087 | } |
| 3088 | |
Al Viro | 4acdaf2 | 2011-07-26 01:42:34 -0400 | [diff] [blame] | 3089 | static int shmem_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
Al Viro | ebfc3b4 | 2012-06-10 18:05:36 -0400 | [diff] [blame] | 3090 | bool excl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3091 | { |
| 3092 | return shmem_mknod(dir, dentry, mode | S_IFREG, 0); |
| 3093 | } |
| 3094 | |
| 3095 | /* |
| 3096 | * Link a file.. |
| 3097 | */ |
| 3098 | static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
| 3099 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3100 | struct inode *inode = d_inode(old_dentry); |
Darrick J. Wong | 4cf6ad0 | 2019-02-22 22:35:32 -0800 | [diff] [blame] | 3101 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3102 | |
| 3103 | /* |
| 3104 | * No ordinary (disk based) filesystem counts links as inodes; |
| 3105 | * but each new link needs a new dentry, pinning lowmem, and |
| 3106 | * tmpfs dentries cannot be pruned until they are unlinked. |
Darrick J. Wong | 00df962 | 2019-02-21 08:48:09 -0800 | [diff] [blame] | 3107 | * But if an O_TMPFILE file is linked into the tmpfs, the |
| 3108 | * first link must skip that, to get the accounting right. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3109 | */ |
Darrick J. Wong | 00df962 | 2019-02-21 08:48:09 -0800 | [diff] [blame] | 3110 | if (inode->i_nlink) { |
| 3111 | ret = shmem_reserve_inode(inode->i_sb); |
| 3112 | if (ret) |
| 3113 | goto out; |
| 3114 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3115 | |
| 3116 | dir->i_size += BOGO_DIRENT_SIZE; |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3117 | inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode); |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 3118 | inc_nlink(inode); |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 3119 | ihold(inode); /* New dentry reference */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3120 | dget(dentry); /* Extra pinning count for the created dentry */ |
| 3121 | d_instantiate(dentry, inode); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 3122 | out: |
| 3123 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3124 | } |
| 3125 | |
| 3126 | static int shmem_unlink(struct inode *dir, struct dentry *dentry) |
| 3127 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3128 | struct inode *inode = d_inode(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3129 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 3130 | if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) |
| 3131 | shmem_free_inode(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3132 | |
| 3133 | dir->i_size -= BOGO_DIRENT_SIZE; |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3134 | inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode); |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 3135 | drop_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3136 | dput(dentry); /* Undo the count from "create" - this does all the work */ |
| 3137 | return 0; |
| 3138 | } |
| 3139 | |
| 3140 | static int shmem_rmdir(struct inode *dir, struct dentry *dentry) |
| 3141 | { |
| 3142 | if (!simple_empty(dentry)) |
| 3143 | return -ENOTEMPTY; |
| 3144 | |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3145 | drop_nlink(d_inode(dentry)); |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 3146 | drop_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3147 | return shmem_unlink(dir, dentry); |
| 3148 | } |
| 3149 | |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 3150 | static int shmem_exchange(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) |
| 3151 | { |
David Howells | e36cb0b | 2015-01-29 12:02:35 +0000 | [diff] [blame] | 3152 | bool old_is_dir = d_is_dir(old_dentry); |
| 3153 | bool new_is_dir = d_is_dir(new_dentry); |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 3154 | |
| 3155 | if (old_dir != new_dir && old_is_dir != new_is_dir) { |
| 3156 | if (old_is_dir) { |
| 3157 | drop_nlink(old_dir); |
| 3158 | inc_nlink(new_dir); |
| 3159 | } else { |
| 3160 | drop_nlink(new_dir); |
| 3161 | inc_nlink(old_dir); |
| 3162 | } |
| 3163 | } |
| 3164 | old_dir->i_ctime = old_dir->i_mtime = |
| 3165 | new_dir->i_ctime = new_dir->i_mtime = |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3166 | d_inode(old_dentry)->i_ctime = |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3167 | d_inode(new_dentry)->i_ctime = current_time(old_dir); |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 3168 | |
| 3169 | return 0; |
| 3170 | } |
| 3171 | |
Miklos Szeredi | 46fdb79 | 2014-10-24 00:14:37 +0200 | [diff] [blame] | 3172 | static int shmem_whiteout(struct inode *old_dir, struct dentry *old_dentry) |
| 3173 | { |
| 3174 | struct dentry *whiteout; |
| 3175 | int error; |
| 3176 | |
| 3177 | whiteout = d_alloc(old_dentry->d_parent, &old_dentry->d_name); |
| 3178 | if (!whiteout) |
| 3179 | return -ENOMEM; |
| 3180 | |
| 3181 | error = shmem_mknod(old_dir, whiteout, |
| 3182 | S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV); |
| 3183 | dput(whiteout); |
| 3184 | if (error) |
| 3185 | return error; |
| 3186 | |
| 3187 | /* |
| 3188 | * Cheat and hash the whiteout while the old dentry is still in |
| 3189 | * place, instead of playing games with FS_RENAME_DOES_D_MOVE. |
| 3190 | * |
| 3191 | * d_lookup() will consistently find one of them at this point, |
| 3192 | * not sure which one, but that isn't even important. |
| 3193 | */ |
| 3194 | d_rehash(whiteout); |
| 3195 | return 0; |
| 3196 | } |
| 3197 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3198 | /* |
| 3199 | * The VFS layer already does all the dentry stuff for rename, |
| 3200 | * we just have to decrement the usage count for the target if |
| 3201 | * it exists so that the VFS layer correctly free's it when it |
| 3202 | * gets overwritten. |
| 3203 | */ |
Miklos Szeredi | 3b69ff5 | 2014-07-23 15:15:33 +0200 | [diff] [blame] | 3204 | static int shmem_rename2(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3205 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3206 | struct inode *inode = d_inode(old_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3207 | int they_are_dirs = S_ISDIR(inode->i_mode); |
| 3208 | |
Miklos Szeredi | 46fdb79 | 2014-10-24 00:14:37 +0200 | [diff] [blame] | 3209 | if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) |
Miklos Szeredi | 3b69ff5 | 2014-07-23 15:15:33 +0200 | [diff] [blame] | 3210 | return -EINVAL; |
| 3211 | |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 3212 | if (flags & RENAME_EXCHANGE) |
| 3213 | return shmem_exchange(old_dir, old_dentry, new_dir, new_dentry); |
| 3214 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3215 | if (!simple_empty(new_dentry)) |
| 3216 | return -ENOTEMPTY; |
| 3217 | |
Miklos Szeredi | 46fdb79 | 2014-10-24 00:14:37 +0200 | [diff] [blame] | 3218 | if (flags & RENAME_WHITEOUT) { |
| 3219 | int error; |
| 3220 | |
| 3221 | error = shmem_whiteout(old_dir, old_dentry); |
| 3222 | if (error) |
| 3223 | return error; |
| 3224 | } |
| 3225 | |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3226 | if (d_really_is_positive(new_dentry)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3227 | (void) shmem_unlink(new_dir, new_dentry); |
Miklos Szeredi | b928095 | 2014-09-24 17:56:17 +0200 | [diff] [blame] | 3228 | if (they_are_dirs) { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3229 | drop_nlink(d_inode(new_dentry)); |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 3230 | drop_nlink(old_dir); |
Miklos Szeredi | b928095 | 2014-09-24 17:56:17 +0200 | [diff] [blame] | 3231 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3232 | } else if (they_are_dirs) { |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 3233 | drop_nlink(old_dir); |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 3234 | inc_nlink(new_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3235 | } |
| 3236 | |
| 3237 | old_dir->i_size -= BOGO_DIRENT_SIZE; |
| 3238 | new_dir->i_size += BOGO_DIRENT_SIZE; |
| 3239 | old_dir->i_ctime = old_dir->i_mtime = |
| 3240 | new_dir->i_ctime = new_dir->i_mtime = |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3241 | inode->i_ctime = current_time(old_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3242 | return 0; |
| 3243 | } |
| 3244 | |
| 3245 | static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *symname) |
| 3246 | { |
| 3247 | int error; |
| 3248 | int len; |
| 3249 | struct inode *inode; |
Hugh Dickins | 9276aad | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3250 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3251 | struct shmem_inode_info *info; |
| 3252 | |
| 3253 | len = strlen(symname) + 1; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3254 | if (len > PAGE_SIZE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3255 | return -ENAMETOOLONG; |
| 3256 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 3257 | inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3258 | if (!inode) |
| 3259 | return -ENOSPC; |
| 3260 | |
Mimi Zohar | 9d8f13b | 2011-06-06 15:29:25 -0400 | [diff] [blame] | 3261 | error = security_inode_init_security(inode, dir, &dentry->d_name, |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3262 | shmem_initxattrs, NULL); |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 3263 | if (error) { |
| 3264 | if (error != -EOPNOTSUPP) { |
| 3265 | iput(inode); |
| 3266 | return error; |
| 3267 | } |
| 3268 | error = 0; |
| 3269 | } |
| 3270 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3271 | info = SHMEM_I(inode); |
| 3272 | inode->i_size = len-1; |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 3273 | if (len <= SHORT_SYMLINK_LEN) { |
Al Viro | 3ed47db | 2016-01-22 18:08:52 -0500 | [diff] [blame] | 3274 | inode->i_link = kmemdup(symname, len, GFP_KERNEL); |
| 3275 | if (!inode->i_link) { |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 3276 | iput(inode); |
| 3277 | return -ENOMEM; |
| 3278 | } |
| 3279 | inode->i_op = &shmem_short_symlink_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3280 | } else { |
Al Viro | e8ecde2 | 2016-01-14 17:52:59 -0500 | [diff] [blame] | 3281 | inode_nohighmem(inode); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 3282 | error = shmem_getpage(inode, 0, &page, SGP_WRITE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3283 | if (error) { |
| 3284 | iput(inode); |
| 3285 | return error; |
| 3286 | } |
Hugh Dickins | 14fcc23 | 2008-07-28 15:46:19 -0700 | [diff] [blame] | 3287 | inode->i_mapping->a_ops = &shmem_aops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3288 | inode->i_op = &shmem_symlink_inode_operations; |
Al Viro | 21fc61c | 2015-11-17 01:07:57 -0500 | [diff] [blame] | 3289 | memcpy(page_address(page), symname, len); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 3290 | SetPageUptodate(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3291 | set_page_dirty(page); |
Wu Fengguang | 6746aff | 2009-09-16 11:50:14 +0200 | [diff] [blame] | 3292 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3293 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3294 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3295 | dir->i_size += BOGO_DIRENT_SIZE; |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3296 | dir->i_ctime = dir->i_mtime = current_time(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3297 | d_instantiate(dentry, inode); |
| 3298 | dget(dentry); |
| 3299 | return 0; |
| 3300 | } |
| 3301 | |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 3302 | static void shmem_put_link(void *arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3303 | { |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 3304 | mark_page_accessed(arg); |
| 3305 | put_page(arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3306 | } |
| 3307 | |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 3308 | static const char *shmem_get_link(struct dentry *dentry, |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 3309 | struct inode *inode, |
| 3310 | struct delayed_call *done) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3311 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3312 | struct page *page = NULL; |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 3313 | int error; |
Al Viro | 6a6c990 | 2015-11-17 10:54:32 -0500 | [diff] [blame] | 3314 | if (!dentry) { |
| 3315 | page = find_get_page(inode->i_mapping, 0); |
| 3316 | if (!page) |
| 3317 | return ERR_PTR(-ECHILD); |
| 3318 | if (!PageUptodate(page)) { |
| 3319 | put_page(page); |
| 3320 | return ERR_PTR(-ECHILD); |
| 3321 | } |
| 3322 | } else { |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 3323 | error = shmem_getpage(inode, 0, &page, SGP_READ); |
Al Viro | 6a6c990 | 2015-11-17 10:54:32 -0500 | [diff] [blame] | 3324 | if (error) |
| 3325 | return ERR_PTR(error); |
| 3326 | unlock_page(page); |
| 3327 | } |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 3328 | set_delayed_call(done, shmem_put_link, page); |
Al Viro | 21fc61c | 2015-11-17 01:07:57 -0500 | [diff] [blame] | 3329 | return page_address(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3330 | } |
| 3331 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3332 | #ifdef CONFIG_TMPFS_XATTR |
| 3333 | /* |
| 3334 | * Superblocks without xattr inode operations may get some security.* xattr |
| 3335 | * support from the LSM "for free". As soon as we have any other xattrs |
| 3336 | * like ACLs, we also need to implement the security.* handlers at |
| 3337 | * filesystem level, though. |
| 3338 | */ |
| 3339 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3340 | /* |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3341 | * Callback for security_inode_init_security() for acquiring xattrs. |
| 3342 | */ |
| 3343 | static int shmem_initxattrs(struct inode *inode, |
| 3344 | const struct xattr *xattr_array, |
| 3345 | void *fs_info) |
| 3346 | { |
| 3347 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 3348 | const struct xattr *xattr; |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 3349 | struct simple_xattr *new_xattr; |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3350 | size_t len; |
| 3351 | |
| 3352 | for (xattr = xattr_array; xattr->name != NULL; xattr++) { |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 3353 | new_xattr = simple_xattr_alloc(xattr->value, xattr->value_len); |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3354 | if (!new_xattr) |
| 3355 | return -ENOMEM; |
| 3356 | |
| 3357 | len = strlen(xattr->name) + 1; |
| 3358 | new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len, |
| 3359 | GFP_KERNEL); |
| 3360 | if (!new_xattr->name) { |
| 3361 | kfree(new_xattr); |
| 3362 | return -ENOMEM; |
| 3363 | } |
| 3364 | |
| 3365 | memcpy(new_xattr->name, XATTR_SECURITY_PREFIX, |
| 3366 | XATTR_SECURITY_PREFIX_LEN); |
| 3367 | memcpy(new_xattr->name + XATTR_SECURITY_PREFIX_LEN, |
| 3368 | xattr->name, len); |
| 3369 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 3370 | simple_xattr_list_add(&info->xattrs, new_xattr); |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3371 | } |
| 3372 | |
| 3373 | return 0; |
| 3374 | } |
| 3375 | |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3376 | static int shmem_xattr_handler_get(const struct xattr_handler *handler, |
Al Viro | b296821 | 2016-04-10 20:48:24 -0400 | [diff] [blame] | 3377 | struct dentry *unused, struct inode *inode, |
| 3378 | const char *name, void *buffer, size_t size) |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3379 | { |
Al Viro | b296821 | 2016-04-10 20:48:24 -0400 | [diff] [blame] | 3380 | struct shmem_inode_info *info = SHMEM_I(inode); |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3381 | |
| 3382 | name = xattr_full_name(handler, name); |
| 3383 | return simple_xattr_get(&info->xattrs, name, buffer, size); |
| 3384 | } |
| 3385 | |
| 3386 | static int shmem_xattr_handler_set(const struct xattr_handler *handler, |
Al Viro | 5930122 | 2016-05-27 10:19:30 -0400 | [diff] [blame] | 3387 | struct dentry *unused, struct inode *inode, |
| 3388 | const char *name, const void *value, |
| 3389 | size_t size, int flags) |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3390 | { |
Al Viro | 5930122 | 2016-05-27 10:19:30 -0400 | [diff] [blame] | 3391 | struct shmem_inode_info *info = SHMEM_I(inode); |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3392 | |
| 3393 | name = xattr_full_name(handler, name); |
| 3394 | return simple_xattr_set(&info->xattrs, name, value, size, flags); |
| 3395 | } |
| 3396 | |
| 3397 | static const struct xattr_handler shmem_security_xattr_handler = { |
| 3398 | .prefix = XATTR_SECURITY_PREFIX, |
| 3399 | .get = shmem_xattr_handler_get, |
| 3400 | .set = shmem_xattr_handler_set, |
| 3401 | }; |
| 3402 | |
| 3403 | static const struct xattr_handler shmem_trusted_xattr_handler = { |
| 3404 | .prefix = XATTR_TRUSTED_PREFIX, |
| 3405 | .get = shmem_xattr_handler_get, |
| 3406 | .set = shmem_xattr_handler_set, |
| 3407 | }; |
| 3408 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3409 | static const struct xattr_handler *shmem_xattr_handlers[] = { |
| 3410 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3411 | &posix_acl_access_xattr_handler, |
| 3412 | &posix_acl_default_xattr_handler, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3413 | #endif |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3414 | &shmem_security_xattr_handler, |
| 3415 | &shmem_trusted_xattr_handler, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3416 | NULL |
| 3417 | }; |
| 3418 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3419 | static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size) |
| 3420 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3421 | struct shmem_inode_info *info = SHMEM_I(d_inode(dentry)); |
Andreas Gruenbacher | 786534b | 2015-12-02 14:44:39 +0100 | [diff] [blame] | 3422 | return simple_xattr_list(d_inode(dentry), &info->xattrs, buffer, size); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3423 | } |
| 3424 | #endif /* CONFIG_TMPFS_XATTR */ |
| 3425 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 3426 | static const struct inode_operations shmem_short_symlink_operations = { |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 3427 | .get_link = simple_get_link, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3428 | #ifdef CONFIG_TMPFS_XATTR |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3429 | .listxattr = shmem_listxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3430 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3431 | }; |
| 3432 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3433 | static const struct inode_operations shmem_symlink_inode_operations = { |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 3434 | .get_link = shmem_get_link, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3435 | #ifdef CONFIG_TMPFS_XATTR |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3436 | .listxattr = shmem_listxattr, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3437 | #endif |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3438 | }; |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3439 | |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3440 | static struct dentry *shmem_get_parent(struct dentry *child) |
| 3441 | { |
| 3442 | return ERR_PTR(-ESTALE); |
| 3443 | } |
| 3444 | |
| 3445 | static int shmem_match(struct inode *ino, void *vfh) |
| 3446 | { |
| 3447 | __u32 *fh = vfh; |
| 3448 | __u64 inum = fh[2]; |
| 3449 | inum = (inum << 32) | fh[1]; |
| 3450 | return ino->i_ino == inum && fh[0] == ino->i_generation; |
| 3451 | } |
| 3452 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3453 | static struct dentry *shmem_fh_to_dentry(struct super_block *sb, |
| 3454 | struct fid *fid, int fh_len, int fh_type) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3455 | { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3456 | struct inode *inode; |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3457 | struct dentry *dentry = NULL; |
Hugh Dickins | 35c2a7f | 2012-10-07 20:32:51 -0700 | [diff] [blame] | 3458 | u64 inum; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3459 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3460 | if (fh_len < 3) |
| 3461 | return NULL; |
| 3462 | |
Hugh Dickins | 35c2a7f | 2012-10-07 20:32:51 -0700 | [diff] [blame] | 3463 | inum = fid->raw[2]; |
| 3464 | inum = (inum << 32) | fid->raw[1]; |
| 3465 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3466 | inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), |
| 3467 | shmem_match, fid->raw); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3468 | if (inode) { |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3469 | dentry = d_find_alias(inode); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3470 | iput(inode); |
| 3471 | } |
| 3472 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3473 | return dentry; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3474 | } |
| 3475 | |
Al Viro | b0b0382 | 2012-04-02 14:34:06 -0400 | [diff] [blame] | 3476 | static int shmem_encode_fh(struct inode *inode, __u32 *fh, int *len, |
| 3477 | struct inode *parent) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3478 | { |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 3479 | if (*len < 3) { |
| 3480 | *len = 3; |
Namjae Jeon | 94e07a75 | 2013-02-17 15:48:11 +0900 | [diff] [blame] | 3481 | return FILEID_INVALID; |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 3482 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3483 | |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 3484 | if (inode_unhashed(inode)) { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3485 | /* Unfortunately insert_inode_hash is not idempotent, |
| 3486 | * so as we hash inodes here rather than at creation |
| 3487 | * time, we need a lock to ensure we only try |
| 3488 | * to do it once |
| 3489 | */ |
| 3490 | static DEFINE_SPINLOCK(lock); |
| 3491 | spin_lock(&lock); |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 3492 | if (inode_unhashed(inode)) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3493 | __insert_inode_hash(inode, |
| 3494 | inode->i_ino + inode->i_generation); |
| 3495 | spin_unlock(&lock); |
| 3496 | } |
| 3497 | |
| 3498 | fh[0] = inode->i_generation; |
| 3499 | fh[1] = inode->i_ino; |
| 3500 | fh[2] = ((__u64)inode->i_ino) >> 32; |
| 3501 | |
| 3502 | *len = 3; |
| 3503 | return 1; |
| 3504 | } |
| 3505 | |
Christoph Hellwig | 3965516 | 2007-10-21 16:42:17 -0700 | [diff] [blame] | 3506 | static const struct export_operations shmem_export_ops = { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3507 | .get_parent = shmem_get_parent, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3508 | .encode_fh = shmem_encode_fh, |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3509 | .fh_to_dentry = shmem_fh_to_dentry, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3510 | }; |
| 3511 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3512 | static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo, |
| 3513 | bool remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3514 | { |
| 3515 | char *this_char, *value, *rest; |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 3516 | struct mempolicy *mpol = NULL; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 3517 | uid_t uid; |
| 3518 | gid_t gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3519 | |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 3520 | while (options != NULL) { |
| 3521 | this_char = options; |
| 3522 | for (;;) { |
| 3523 | /* |
| 3524 | * NUL-terminate this option: unfortunately, |
| 3525 | * mount options form a comma-separated list, |
| 3526 | * but mpol's nodelist may also contain commas. |
| 3527 | */ |
| 3528 | options = strchr(options, ','); |
| 3529 | if (options == NULL) |
| 3530 | break; |
| 3531 | options++; |
| 3532 | if (!isdigit(*options)) { |
| 3533 | options[-1] = '\0'; |
| 3534 | break; |
| 3535 | } |
| 3536 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3537 | if (!*this_char) |
| 3538 | continue; |
| 3539 | if ((value = strchr(this_char,'=')) != NULL) { |
| 3540 | *value++ = 0; |
| 3541 | } else { |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 3542 | pr_err("tmpfs: No value for mount option '%s'\n", |
| 3543 | this_char); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 3544 | goto error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3545 | } |
| 3546 | |
| 3547 | if (!strcmp(this_char,"size")) { |
| 3548 | unsigned long long size; |
| 3549 | size = memparse(value,&rest); |
| 3550 | if (*rest == '%') { |
| 3551 | size <<= PAGE_SHIFT; |
| 3552 | size *= totalram_pages; |
| 3553 | do_div(size, 100); |
| 3554 | rest++; |
| 3555 | } |
| 3556 | if (*rest) |
| 3557 | goto bad_val; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3558 | sbinfo->max_blocks = |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3559 | DIV_ROUND_UP(size, PAGE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3560 | } else if (!strcmp(this_char,"nr_blocks")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3561 | sbinfo->max_blocks = memparse(value, &rest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3562 | if (*rest) |
| 3563 | goto bad_val; |
| 3564 | } else if (!strcmp(this_char,"nr_inodes")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3565 | sbinfo->max_inodes = memparse(value, &rest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3566 | if (*rest) |
| 3567 | goto bad_val; |
| 3568 | } else if (!strcmp(this_char,"mode")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3569 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3570 | continue; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3571 | sbinfo->mode = simple_strtoul(value, &rest, 8) & 07777; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3572 | if (*rest) |
| 3573 | goto bad_val; |
| 3574 | } else if (!strcmp(this_char,"uid")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3575 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3576 | continue; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 3577 | uid = simple_strtoul(value, &rest, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3578 | if (*rest) |
| 3579 | goto bad_val; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 3580 | sbinfo->uid = make_kuid(current_user_ns(), uid); |
| 3581 | if (!uid_valid(sbinfo->uid)) |
| 3582 | goto bad_val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3583 | } else if (!strcmp(this_char,"gid")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3584 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3585 | continue; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 3586 | gid = simple_strtoul(value, &rest, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3587 | if (*rest) |
| 3588 | goto bad_val; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 3589 | sbinfo->gid = make_kgid(current_user_ns(), gid); |
| 3590 | if (!gid_valid(sbinfo->gid)) |
| 3591 | goto bad_val; |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 3592 | #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 3593 | } else if (!strcmp(this_char, "huge")) { |
| 3594 | int huge; |
| 3595 | huge = shmem_parse_huge(value); |
| 3596 | if (huge < 0) |
| 3597 | goto bad_val; |
| 3598 | if (!has_transparent_hugepage() && |
| 3599 | huge != SHMEM_HUGE_NEVER) |
| 3600 | goto bad_val; |
| 3601 | sbinfo->huge = huge; |
| 3602 | #endif |
| 3603 | #ifdef CONFIG_NUMA |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 3604 | } else if (!strcmp(this_char,"mpol")) { |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 3605 | mpol_put(mpol); |
| 3606 | mpol = NULL; |
| 3607 | if (mpol_parse_str(value, &mpol)) |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 3608 | goto bad_val; |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 3609 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3610 | } else { |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 3611 | pr_err("tmpfs: Bad mount option %s\n", this_char); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 3612 | goto error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3613 | } |
| 3614 | } |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 3615 | sbinfo->mpol = mpol; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3616 | return 0; |
| 3617 | |
| 3618 | bad_val: |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 3619 | pr_err("tmpfs: Bad value '%s' for mount option '%s'\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3620 | value, this_char); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 3621 | error: |
| 3622 | mpol_put(mpol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3623 | return 1; |
| 3624 | |
| 3625 | } |
| 3626 | |
| 3627 | static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) |
| 3628 | { |
| 3629 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3630 | struct shmem_sb_info config = *sbinfo; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3631 | unsigned long inodes; |
| 3632 | int error = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3633 | |
Greg Thelen | 5f00110 | 2013-02-22 16:36:01 -0800 | [diff] [blame] | 3634 | config.mpol = NULL; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3635 | if (shmem_parse_options(data, &config, true)) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3636 | return error; |
| 3637 | |
| 3638 | spin_lock(&sbinfo->stat_lock); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3639 | inodes = sbinfo->max_inodes - sbinfo->free_inodes; |
Tim Chen | 7e49629 | 2010-08-09 17:19:05 -0700 | [diff] [blame] | 3640 | if (percpu_counter_compare(&sbinfo->used_blocks, config.max_blocks) > 0) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3641 | goto out; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3642 | if (config.max_inodes < inodes) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3643 | goto out; |
| 3644 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 3645 | * Those tests disallow limited->unlimited while any are in use; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3646 | * but we must separately disallow unlimited->limited, because |
| 3647 | * in that case we have no record of how much is already in use. |
| 3648 | */ |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3649 | if (config.max_blocks && !sbinfo->max_blocks) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3650 | goto out; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3651 | if (config.max_inodes && !sbinfo->max_inodes) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3652 | goto out; |
| 3653 | |
| 3654 | error = 0; |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 3655 | sbinfo->huge = config.huge; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3656 | sbinfo->max_blocks = config.max_blocks; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3657 | sbinfo->max_inodes = config.max_inodes; |
| 3658 | sbinfo->free_inodes = config.max_inodes - inodes; |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 3659 | |
Greg Thelen | 5f00110 | 2013-02-22 16:36:01 -0800 | [diff] [blame] | 3660 | /* |
| 3661 | * Preserve previous mempolicy unless mpol remount option was specified. |
| 3662 | */ |
| 3663 | if (config.mpol) { |
| 3664 | mpol_put(sbinfo->mpol); |
| 3665 | sbinfo->mpol = config.mpol; /* transfers initial ref */ |
| 3666 | } |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3667 | out: |
| 3668 | spin_unlock(&sbinfo->stat_lock); |
| 3669 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3670 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3671 | |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 3672 | static int shmem_show_options(struct seq_file *seq, struct dentry *root) |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3673 | { |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 3674 | struct shmem_sb_info *sbinfo = SHMEM_SB(root->d_sb); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3675 | |
| 3676 | if (sbinfo->max_blocks != shmem_default_max_blocks()) |
| 3677 | seq_printf(seq, ",size=%luk", |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3678 | sbinfo->max_blocks << (PAGE_SHIFT - 10)); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3679 | if (sbinfo->max_inodes != shmem_default_max_inodes()) |
| 3680 | seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes); |
| 3681 | if (sbinfo->mode != (S_IRWXUGO | S_ISVTX)) |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 3682 | seq_printf(seq, ",mode=%03ho", sbinfo->mode); |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 3683 | if (!uid_eq(sbinfo->uid, GLOBAL_ROOT_UID)) |
| 3684 | seq_printf(seq, ",uid=%u", |
| 3685 | from_kuid_munged(&init_user_ns, sbinfo->uid)); |
| 3686 | if (!gid_eq(sbinfo->gid, GLOBAL_ROOT_GID)) |
| 3687 | seq_printf(seq, ",gid=%u", |
| 3688 | from_kgid_munged(&init_user_ns, sbinfo->gid)); |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 3689 | #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 3690 | /* Rightly or wrongly, show huge mount option unmasked by shmem_huge */ |
| 3691 | if (sbinfo->huge) |
| 3692 | seq_printf(seq, ",huge=%s", shmem_format_huge(sbinfo->huge)); |
| 3693 | #endif |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 3694 | shmem_show_mpol(seq, sbinfo->mpol); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3695 | return 0; |
| 3696 | } |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 3697 | |
| 3698 | #define MFD_NAME_PREFIX "memfd:" |
| 3699 | #define MFD_NAME_PREFIX_LEN (sizeof(MFD_NAME_PREFIX) - 1) |
| 3700 | #define MFD_NAME_MAX_LEN (NAME_MAX - MFD_NAME_PREFIX_LEN) |
| 3701 | |
Mike Kravetz | 749df87 | 2017-09-06 16:24:16 -0700 | [diff] [blame] | 3702 | #define MFD_ALL_FLAGS (MFD_CLOEXEC | MFD_ALLOW_SEALING | MFD_HUGETLB) |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 3703 | |
| 3704 | SYSCALL_DEFINE2(memfd_create, |
| 3705 | const char __user *, uname, |
| 3706 | unsigned int, flags) |
| 3707 | { |
| 3708 | struct shmem_inode_info *info; |
| 3709 | struct file *file; |
| 3710 | int fd, error; |
| 3711 | char *name; |
| 3712 | long len; |
| 3713 | |
Mike Kravetz | 749df87 | 2017-09-06 16:24:16 -0700 | [diff] [blame] | 3714 | if (!(flags & MFD_HUGETLB)) { |
| 3715 | if (flags & ~(unsigned int)MFD_ALL_FLAGS) |
| 3716 | return -EINVAL; |
| 3717 | } else { |
| 3718 | /* Sealing not supported in hugetlbfs (MFD_HUGETLB) */ |
| 3719 | if (flags & MFD_ALLOW_SEALING) |
| 3720 | return -EINVAL; |
| 3721 | /* Allow huge page size encoding in flags. */ |
| 3722 | if (flags & ~(unsigned int)(MFD_ALL_FLAGS | |
| 3723 | (MFD_HUGE_MASK << MFD_HUGE_SHIFT))) |
| 3724 | return -EINVAL; |
| 3725 | } |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 3726 | |
| 3727 | /* length includes terminating zero */ |
| 3728 | len = strnlen_user(uname, MFD_NAME_MAX_LEN + 1); |
| 3729 | if (len <= 0) |
| 3730 | return -EFAULT; |
| 3731 | if (len > MFD_NAME_MAX_LEN + 1) |
| 3732 | return -EINVAL; |
| 3733 | |
Michal Hocko | 0ee931c | 2017-09-13 16:28:29 -0700 | [diff] [blame] | 3734 | name = kmalloc(len + MFD_NAME_PREFIX_LEN, GFP_KERNEL); |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 3735 | if (!name) |
| 3736 | return -ENOMEM; |
| 3737 | |
| 3738 | strcpy(name, MFD_NAME_PREFIX); |
| 3739 | if (copy_from_user(&name[MFD_NAME_PREFIX_LEN], uname, len)) { |
| 3740 | error = -EFAULT; |
| 3741 | goto err_name; |
| 3742 | } |
| 3743 | |
| 3744 | /* terminating-zero may have changed after strnlen_user() returned */ |
| 3745 | if (name[len + MFD_NAME_PREFIX_LEN - 1]) { |
| 3746 | error = -EFAULT; |
| 3747 | goto err_name; |
| 3748 | } |
| 3749 | |
| 3750 | fd = get_unused_fd_flags((flags & MFD_CLOEXEC) ? O_CLOEXEC : 0); |
| 3751 | if (fd < 0) { |
| 3752 | error = fd; |
| 3753 | goto err_name; |
| 3754 | } |
| 3755 | |
Mike Kravetz | 749df87 | 2017-09-06 16:24:16 -0700 | [diff] [blame] | 3756 | if (flags & MFD_HUGETLB) { |
| 3757 | struct user_struct *user = NULL; |
| 3758 | |
| 3759 | file = hugetlb_file_setup(name, 0, VM_NORESERVE, &user, |
| 3760 | HUGETLB_ANONHUGE_INODE, |
| 3761 | (flags >> MFD_HUGE_SHIFT) & |
| 3762 | MFD_HUGE_MASK); |
| 3763 | } else |
| 3764 | file = shmem_file_setup(name, 0, VM_NORESERVE); |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 3765 | if (IS_ERR(file)) { |
| 3766 | error = PTR_ERR(file); |
| 3767 | goto err_fd; |
| 3768 | } |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 3769 | file->f_mode |= FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE; |
| 3770 | file->f_flags |= O_RDWR | O_LARGEFILE; |
Mike Kravetz | 749df87 | 2017-09-06 16:24:16 -0700 | [diff] [blame] | 3771 | |
| 3772 | if (flags & MFD_ALLOW_SEALING) { |
| 3773 | /* |
| 3774 | * flags check at beginning of function ensures |
| 3775 | * this is not a hugetlbfs (MFD_HUGETLB) file. |
| 3776 | */ |
| 3777 | info = SHMEM_I(file_inode(file)); |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 3778 | info->seals &= ~F_SEAL_SEAL; |
Mike Kravetz | 749df87 | 2017-09-06 16:24:16 -0700 | [diff] [blame] | 3779 | } |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 3780 | |
| 3781 | fd_install(fd, file); |
| 3782 | kfree(name); |
| 3783 | return fd; |
| 3784 | |
| 3785 | err_fd: |
| 3786 | put_unused_fd(fd); |
| 3787 | err_name: |
| 3788 | kfree(name); |
| 3789 | return error; |
| 3790 | } |
| 3791 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3792 | #endif /* CONFIG_TMPFS */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3793 | |
| 3794 | static void shmem_put_super(struct super_block *sb) |
| 3795 | { |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 3796 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 3797 | |
| 3798 | percpu_counter_destroy(&sbinfo->used_blocks); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 3799 | mpol_put(sbinfo->mpol); |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 3800 | kfree(sbinfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3801 | sb->s_fs_info = NULL; |
| 3802 | } |
| 3803 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 3804 | int shmem_fill_super(struct super_block *sb, void *data, int silent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3805 | { |
| 3806 | struct inode *inode; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3807 | struct shmem_sb_info *sbinfo; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3808 | int err = -ENOMEM; |
| 3809 | |
| 3810 | /* Round up to L1_CACHE_BYTES to resist false sharing */ |
Pekka Enberg | 425fbf0 | 2009-09-21 17:03:50 -0700 | [diff] [blame] | 3811 | sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info), |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3812 | L1_CACHE_BYTES), GFP_KERNEL); |
| 3813 | if (!sbinfo) |
| 3814 | return -ENOMEM; |
| 3815 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3816 | sbinfo->mode = S_IRWXUGO | S_ISVTX; |
David Howells | 76aac0e | 2008-11-14 10:39:12 +1100 | [diff] [blame] | 3817 | sbinfo->uid = current_fsuid(); |
| 3818 | sbinfo->gid = current_fsgid(); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3819 | sb->s_fs_info = sbinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3820 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3821 | #ifdef CONFIG_TMPFS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3822 | /* |
| 3823 | * Per default we only allow half of the physical ram per |
| 3824 | * tmpfs instance, limiting inodes to one per page of lowmem; |
| 3825 | * but the internal instance is left unlimited. |
| 3826 | */ |
Al Viro | ca4e051 | 2013-08-31 12:57:10 -0400 | [diff] [blame] | 3827 | if (!(sb->s_flags & MS_KERNMOUNT)) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3828 | sbinfo->max_blocks = shmem_default_max_blocks(); |
| 3829 | sbinfo->max_inodes = shmem_default_max_inodes(); |
| 3830 | if (shmem_parse_options(data, sbinfo, false)) { |
| 3831 | err = -EINVAL; |
| 3832 | goto failed; |
| 3833 | } |
Al Viro | ca4e051 | 2013-08-31 12:57:10 -0400 | [diff] [blame] | 3834 | } else { |
| 3835 | sb->s_flags |= MS_NOUSER; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3836 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3837 | sb->s_export_op = &shmem_export_ops; |
Hugh Dickins | 2f6e38f | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 3838 | sb->s_flags |= MS_NOSEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3839 | #else |
| 3840 | sb->s_flags |= MS_NOUSER; |
| 3841 | #endif |
| 3842 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3843 | spin_lock_init(&sbinfo->stat_lock); |
Tejun Heo | 908c7f1 | 2014-09-08 09:51:29 +0900 | [diff] [blame] | 3844 | if (percpu_counter_init(&sbinfo->used_blocks, 0, GFP_KERNEL)) |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 3845 | goto failed; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3846 | sbinfo->free_inodes = sbinfo->max_inodes; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 3847 | spin_lock_init(&sbinfo->shrinklist_lock); |
| 3848 | INIT_LIST_HEAD(&sbinfo->shrinklist); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3849 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 3850 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3851 | sb->s_blocksize = PAGE_SIZE; |
| 3852 | sb->s_blocksize_bits = PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3853 | sb->s_magic = TMPFS_MAGIC; |
| 3854 | sb->s_op = &shmem_ops; |
Robin H. Johnson | cfd95a9 | 2006-06-12 21:50:25 +0100 | [diff] [blame] | 3855 | sb->s_time_gran = 1; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3856 | #ifdef CONFIG_TMPFS_XATTR |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3857 | sb->s_xattr = shmem_xattr_handlers; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3858 | #endif |
| 3859 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3860 | sb->s_flags |= MS_POSIXACL; |
| 3861 | #endif |
Amir Goldstein | 2b4db79 | 2017-05-18 15:29:33 +0300 | [diff] [blame] | 3862 | uuid_gen(&sb->s_uuid); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3863 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 3864 | inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3865 | if (!inode) |
| 3866 | goto failed; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3867 | inode->i_uid = sbinfo->uid; |
| 3868 | inode->i_gid = sbinfo->gid; |
Al Viro | 318ceed | 2012-02-12 22:08:01 -0500 | [diff] [blame] | 3869 | sb->s_root = d_make_root(inode); |
| 3870 | if (!sb->s_root) |
Al Viro | 48fde70 | 2012-01-08 22:15:13 -0500 | [diff] [blame] | 3871 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3872 | return 0; |
| 3873 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3874 | failed: |
| 3875 | shmem_put_super(sb); |
| 3876 | return err; |
| 3877 | } |
| 3878 | |
Pekka Enberg | fcc234f | 2006-03-22 00:08:13 -0800 | [diff] [blame] | 3879 | static struct kmem_cache *shmem_inode_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3880 | |
| 3881 | static struct inode *shmem_alloc_inode(struct super_block *sb) |
| 3882 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3883 | struct shmem_inode_info *info; |
| 3884 | info = kmem_cache_alloc(shmem_inode_cachep, GFP_KERNEL); |
| 3885 | if (!info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3886 | return NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3887 | return &info->vfs_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3888 | } |
| 3889 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3890 | static void shmem_destroy_callback(struct rcu_head *head) |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 3891 | { |
| 3892 | struct inode *inode = container_of(head, struct inode, i_rcu); |
Al Viro | 84e710d | 2016-04-15 00:58:55 -0400 | [diff] [blame] | 3893 | if (S_ISLNK(inode->i_mode)) |
| 3894 | kfree(inode->i_link); |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 3895 | kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode)); |
| 3896 | } |
| 3897 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3898 | static void shmem_destroy_inode(struct inode *inode) |
| 3899 | { |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 3900 | if (S_ISREG(inode->i_mode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3901 | mpol_free_shared_policy(&SHMEM_I(inode)->policy); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3902 | call_rcu(&inode->i_rcu, shmem_destroy_callback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3903 | } |
| 3904 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3905 | static void shmem_init_inode(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3906 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3907 | struct shmem_inode_info *info = foo; |
| 3908 | inode_init_once(&info->vfs_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3909 | } |
| 3910 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3911 | static int shmem_init_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3912 | { |
| 3913 | shmem_inode_cachep = kmem_cache_create("shmem_inode_cache", |
| 3914 | sizeof(struct shmem_inode_info), |
Vladimir Davydov | 5d09705 | 2016-01-14 15:18:21 -0800 | [diff] [blame] | 3915 | 0, SLAB_PANIC|SLAB_ACCOUNT, shmem_init_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3916 | return 0; |
| 3917 | } |
| 3918 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3919 | static void shmem_destroy_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3920 | { |
Alexey Dobriyan | 1a1d92c | 2006-09-27 01:49:40 -0700 | [diff] [blame] | 3921 | kmem_cache_destroy(shmem_inode_cachep); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3922 | } |
| 3923 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 3924 | static const struct address_space_operations shmem_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3925 | .writepage = shmem_writepage, |
Ken Chen | 7671932 | 2007-02-10 01:43:15 -0800 | [diff] [blame] | 3926 | .set_page_dirty = __set_page_dirty_no_writeback, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3927 | #ifdef CONFIG_TMPFS |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 3928 | .write_begin = shmem_write_begin, |
| 3929 | .write_end = shmem_write_end, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3930 | #endif |
Andrew Morton | 1c93923 | 2014-10-09 15:27:59 -0700 | [diff] [blame] | 3931 | #ifdef CONFIG_MIGRATION |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 3932 | .migratepage = migrate_page, |
Andrew Morton | 1c93923 | 2014-10-09 15:27:59 -0700 | [diff] [blame] | 3933 | #endif |
Andi Kleen | aa261f5 | 2009-09-16 11:50:16 +0200 | [diff] [blame] | 3934 | .error_remove_page = generic_error_remove_page, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3935 | }; |
| 3936 | |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 3937 | static const struct file_operations shmem_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3938 | .mmap = shmem_mmap, |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 3939 | .get_unmapped_area = shmem_get_unmapped_area, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3940 | #ifdef CONFIG_TMPFS |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 3941 | .llseek = shmem_file_llseek, |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 3942 | .read_iter = shmem_file_read_iter, |
Al Viro | 8174202 | 2014-04-03 03:17:43 -0400 | [diff] [blame] | 3943 | .write_iter = generic_file_write_iter, |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 3944 | .fsync = noop_fsync, |
Al Viro | 82c156f | 2016-09-22 23:35:42 -0400 | [diff] [blame] | 3945 | .splice_read = generic_file_splice_read, |
Al Viro | f6cb85d | 2014-04-05 04:38:56 -0400 | [diff] [blame] | 3946 | .splice_write = iter_file_splice_write, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 3947 | .fallocate = shmem_fallocate, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3948 | #endif |
| 3949 | }; |
| 3950 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3951 | static const struct inode_operations shmem_inode_operations = { |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 3952 | .getattr = shmem_getattr, |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3953 | .setattr = shmem_setattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3954 | #ifdef CONFIG_TMPFS_XATTR |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3955 | .listxattr = shmem_listxattr, |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3956 | .set_acl = simple_set_acl, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3957 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3958 | }; |
| 3959 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3960 | static const struct inode_operations shmem_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3961 | #ifdef CONFIG_TMPFS |
| 3962 | .create = shmem_create, |
| 3963 | .lookup = simple_lookup, |
| 3964 | .link = shmem_link, |
| 3965 | .unlink = shmem_unlink, |
| 3966 | .symlink = shmem_symlink, |
| 3967 | .mkdir = shmem_mkdir, |
| 3968 | .rmdir = shmem_rmdir, |
| 3969 | .mknod = shmem_mknod, |
Miklos Szeredi | 2773bf0 | 2016-09-27 11:03:58 +0200 | [diff] [blame] | 3970 | .rename = shmem_rename2, |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 3971 | .tmpfile = shmem_tmpfile, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3972 | #endif |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3973 | #ifdef CONFIG_TMPFS_XATTR |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3974 | .listxattr = shmem_listxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3975 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3976 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3977 | .setattr = shmem_setattr, |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3978 | .set_acl = simple_set_acl, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3979 | #endif |
| 3980 | }; |
| 3981 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3982 | static const struct inode_operations shmem_special_inode_operations = { |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3983 | #ifdef CONFIG_TMPFS_XATTR |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3984 | .listxattr = shmem_listxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3985 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3986 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3987 | .setattr = shmem_setattr, |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3988 | .set_acl = simple_set_acl, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3989 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3990 | }; |
| 3991 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 3992 | static const struct super_operations shmem_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3993 | .alloc_inode = shmem_alloc_inode, |
| 3994 | .destroy_inode = shmem_destroy_inode, |
| 3995 | #ifdef CONFIG_TMPFS |
| 3996 | .statfs = shmem_statfs, |
| 3997 | .remount_fs = shmem_remount_fs, |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3998 | .show_options = shmem_show_options, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3999 | #endif |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 4000 | .evict_inode = shmem_evict_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4001 | .drop_inode = generic_delete_inode, |
| 4002 | .put_super = shmem_put_super, |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 4003 | #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE |
| 4004 | .nr_cached_objects = shmem_unused_huge_count, |
| 4005 | .free_cached_objects = shmem_unused_huge_scan, |
| 4006 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4007 | }; |
| 4008 | |
Alexey Dobriyan | f0f37e2 | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 4009 | static const struct vm_operations_struct shmem_vm_ops = { |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 4010 | .fault = shmem_fault, |
Ning Qu | d7c1755 | 2014-04-07 15:37:24 -0700 | [diff] [blame] | 4011 | .map_pages = filemap_map_pages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4012 | #ifdef CONFIG_NUMA |
| 4013 | .set_policy = shmem_set_policy, |
| 4014 | .get_policy = shmem_get_policy, |
| 4015 | #endif |
| 4016 | }; |
| 4017 | |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 4018 | static struct dentry *shmem_mount(struct file_system_type *fs_type, |
| 4019 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4020 | { |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 4021 | return mount_nodev(fs_type, flags, data, shmem_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4022 | } |
| 4023 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4024 | static struct file_system_type shmem_fs_type = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4025 | .owner = THIS_MODULE, |
| 4026 | .name = "tmpfs", |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 4027 | .mount = shmem_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4028 | .kill_sb = kill_litter_super, |
Eric W. Biederman | 2b8576c | 2013-01-25 16:32:10 -0800 | [diff] [blame] | 4029 | .fs_flags = FS_USERNS_MOUNT, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4030 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4031 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4032 | int __init shmem_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4033 | { |
| 4034 | int error; |
| 4035 | |
Rob Landley | 16203a7 | 2013-09-11 14:26:12 -0700 | [diff] [blame] | 4036 | /* If rootfs called this, don't re-init */ |
| 4037 | if (shmem_inode_cachep) |
| 4038 | return 0; |
| 4039 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4040 | error = shmem_init_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4041 | if (error) |
| 4042 | goto out3; |
| 4043 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4044 | error = register_filesystem(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4045 | if (error) { |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 4046 | pr_err("Could not register tmpfs\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4047 | goto out2; |
| 4048 | } |
Greg Kroah-Hartman | 95dc112 | 2005-06-20 21:15:16 -0700 | [diff] [blame] | 4049 | |
Al Viro | ca4e051 | 2013-08-31 12:57:10 -0400 | [diff] [blame] | 4050 | shm_mnt = kern_mount(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4051 | if (IS_ERR(shm_mnt)) { |
| 4052 | error = PTR_ERR(shm_mnt); |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 4053 | pr_err("Could not kern_mount tmpfs\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4054 | goto out1; |
| 4055 | } |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 4056 | |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 4057 | #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE |
Kirill A. Shutemov | 435c0b87 | 2017-08-25 15:55:33 -0700 | [diff] [blame] | 4058 | if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY) |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 4059 | SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge; |
| 4060 | else |
| 4061 | shmem_huge = 0; /* just in case it was patched */ |
| 4062 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4063 | return 0; |
| 4064 | |
| 4065 | out1: |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4066 | unregister_filesystem(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4067 | out2: |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4068 | shmem_destroy_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4069 | out3: |
| 4070 | shm_mnt = ERR_PTR(error); |
| 4071 | return error; |
| 4072 | } |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4073 | |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 4074 | #if defined(CONFIG_TRANSPARENT_HUGE_PAGECACHE) && defined(CONFIG_SYSFS) |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 4075 | static ssize_t shmem_enabled_show(struct kobject *kobj, |
| 4076 | struct kobj_attribute *attr, char *buf) |
| 4077 | { |
| 4078 | int values[] = { |
| 4079 | SHMEM_HUGE_ALWAYS, |
| 4080 | SHMEM_HUGE_WITHIN_SIZE, |
| 4081 | SHMEM_HUGE_ADVISE, |
| 4082 | SHMEM_HUGE_NEVER, |
| 4083 | SHMEM_HUGE_DENY, |
| 4084 | SHMEM_HUGE_FORCE, |
| 4085 | }; |
| 4086 | int i, count; |
| 4087 | |
| 4088 | for (i = 0, count = 0; i < ARRAY_SIZE(values); i++) { |
| 4089 | const char *fmt = shmem_huge == values[i] ? "[%s] " : "%s "; |
| 4090 | |
| 4091 | count += sprintf(buf + count, fmt, |
| 4092 | shmem_format_huge(values[i])); |
| 4093 | } |
| 4094 | buf[count - 1] = '\n'; |
| 4095 | return count; |
| 4096 | } |
| 4097 | |
| 4098 | static ssize_t shmem_enabled_store(struct kobject *kobj, |
| 4099 | struct kobj_attribute *attr, const char *buf, size_t count) |
| 4100 | { |
| 4101 | char tmp[16]; |
| 4102 | int huge; |
| 4103 | |
| 4104 | if (count + 1 > sizeof(tmp)) |
| 4105 | return -EINVAL; |
| 4106 | memcpy(tmp, buf, count); |
| 4107 | tmp[count] = '\0'; |
| 4108 | if (count && tmp[count - 1] == '\n') |
| 4109 | tmp[count - 1] = '\0'; |
| 4110 | |
| 4111 | huge = shmem_parse_huge(tmp); |
| 4112 | if (huge == -EINVAL) |
| 4113 | return -EINVAL; |
| 4114 | if (!has_transparent_hugepage() && |
| 4115 | huge != SHMEM_HUGE_NEVER && huge != SHMEM_HUGE_DENY) |
| 4116 | return -EINVAL; |
| 4117 | |
| 4118 | shmem_huge = huge; |
Kirill A. Shutemov | 435c0b87 | 2017-08-25 15:55:33 -0700 | [diff] [blame] | 4119 | if (shmem_huge > SHMEM_HUGE_DENY) |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 4120 | SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge; |
| 4121 | return count; |
| 4122 | } |
| 4123 | |
| 4124 | struct kobj_attribute shmem_enabled_attr = |
| 4125 | __ATTR(shmem_enabled, 0644, shmem_enabled_show, shmem_enabled_store); |
Arnd Bergmann | 3b33719 | 2016-08-10 16:27:44 -0700 | [diff] [blame] | 4126 | #endif /* CONFIG_TRANSPARENT_HUGE_PAGECACHE && CONFIG_SYSFS */ |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 4127 | |
Arnd Bergmann | 3b33719 | 2016-08-10 16:27:44 -0700 | [diff] [blame] | 4128 | #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 4129 | bool shmem_huge_enabled(struct vm_area_struct *vma) |
| 4130 | { |
| 4131 | struct inode *inode = file_inode(vma->vm_file); |
| 4132 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
| 4133 | loff_t i_size; |
| 4134 | pgoff_t off; |
| 4135 | |
| 4136 | if (shmem_huge == SHMEM_HUGE_FORCE) |
| 4137 | return true; |
| 4138 | if (shmem_huge == SHMEM_HUGE_DENY) |
| 4139 | return false; |
| 4140 | switch (sbinfo->huge) { |
| 4141 | case SHMEM_HUGE_NEVER: |
| 4142 | return false; |
| 4143 | case SHMEM_HUGE_ALWAYS: |
| 4144 | return true; |
| 4145 | case SHMEM_HUGE_WITHIN_SIZE: |
| 4146 | off = round_up(vma->vm_pgoff, HPAGE_PMD_NR); |
| 4147 | i_size = round_up(i_size_read(inode), PAGE_SIZE); |
| 4148 | if (i_size >= HPAGE_PMD_SIZE && |
| 4149 | i_size >> PAGE_SHIFT >= off) |
| 4150 | return true; |
| 4151 | case SHMEM_HUGE_ADVISE: |
| 4152 | /* TODO: implement fadvise() hints */ |
| 4153 | return (vma->vm_flags & VM_HUGEPAGE); |
| 4154 | default: |
| 4155 | VM_BUG_ON(1); |
| 4156 | return false; |
| 4157 | } |
| 4158 | } |
Arnd Bergmann | 3b33719 | 2016-08-10 16:27:44 -0700 | [diff] [blame] | 4159 | #endif /* CONFIG_TRANSPARENT_HUGE_PAGECACHE */ |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 4160 | |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4161 | #else /* !CONFIG_SHMEM */ |
| 4162 | |
| 4163 | /* |
| 4164 | * tiny-shmem: simple shmemfs and tmpfs using ramfs code |
| 4165 | * |
| 4166 | * This is intended for small system where the benefits of the full |
| 4167 | * shmem code (swap-backed and resource-limited) are outweighed by |
| 4168 | * their complexity. On systems without swap this code should be |
| 4169 | * effectively equivalent, but much lighter weight. |
| 4170 | */ |
| 4171 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4172 | static struct file_system_type shmem_fs_type = { |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4173 | .name = "tmpfs", |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 4174 | .mount = ramfs_mount, |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4175 | .kill_sb = kill_litter_super, |
Eric W. Biederman | 2b8576c | 2013-01-25 16:32:10 -0800 | [diff] [blame] | 4176 | .fs_flags = FS_USERNS_MOUNT, |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4177 | }; |
| 4178 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4179 | int __init shmem_init(void) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4180 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4181 | BUG_ON(register_filesystem(&shmem_fs_type) != 0); |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4182 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4183 | shm_mnt = kern_mount(&shmem_fs_type); |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4184 | BUG_ON(IS_ERR(shm_mnt)); |
| 4185 | |
| 4186 | return 0; |
| 4187 | } |
| 4188 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4189 | int shmem_unuse(swp_entry_t swap, struct page *page) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4190 | { |
| 4191 | return 0; |
| 4192 | } |
| 4193 | |
Hugh Dickins | 3f96b79 | 2009-09-21 17:03:37 -0700 | [diff] [blame] | 4194 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 4195 | { |
| 4196 | return 0; |
| 4197 | } |
| 4198 | |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 4199 | void shmem_unlock_mapping(struct address_space *mapping) |
| 4200 | { |
| 4201 | } |
| 4202 | |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 4203 | #ifdef CONFIG_MMU |
| 4204 | unsigned long shmem_get_unmapped_area(struct file *file, |
| 4205 | unsigned long addr, unsigned long len, |
| 4206 | unsigned long pgoff, unsigned long flags) |
| 4207 | { |
| 4208 | return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); |
| 4209 | } |
| 4210 | #endif |
| 4211 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4212 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend) |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 4213 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4214 | truncate_inode_pages_range(inode->i_mapping, lstart, lend); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 4215 | } |
| 4216 | EXPORT_SYMBOL_GPL(shmem_truncate_range); |
| 4217 | |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 4218 | #define shmem_vm_ops generic_file_vm_ops |
| 4219 | #define shmem_file_operations ramfs_file_operations |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 4220 | #define shmem_get_inode(sb, dir, mode, dev, flags) ramfs_get_inode(sb, dir, mode, dev) |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 4221 | #define shmem_acct_size(flags, size) 0 |
| 4222 | #define shmem_unacct_size(flags, size) do {} while (0) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4223 | |
| 4224 | #endif /* CONFIG_SHMEM */ |
| 4225 | |
| 4226 | /* common code */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4227 | |
Rasmus Villemoes | 19938e3 | 2016-10-07 17:01:01 -0700 | [diff] [blame] | 4228 | static const struct dentry_operations anon_ops = { |
Al Viro | 118b230 | 2013-08-24 12:08:17 -0400 | [diff] [blame] | 4229 | .d_dname = simple_dname |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 4230 | }; |
| 4231 | |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 4232 | static struct file *__shmem_file_setup(const char *name, loff_t size, |
| 4233 | unsigned long flags, unsigned int i_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4234 | { |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 4235 | struct file *res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4236 | struct inode *inode; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 4237 | struct path path; |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 4238 | struct super_block *sb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4239 | struct qstr this; |
| 4240 | |
| 4241 | if (IS_ERR(shm_mnt)) |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 4242 | return ERR_CAST(shm_mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4243 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 4244 | if (size < 0 || size > MAX_LFS_FILESIZE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4245 | return ERR_PTR(-EINVAL); |
| 4246 | |
| 4247 | if (shmem_acct_size(flags, size)) |
| 4248 | return ERR_PTR(-ENOMEM); |
| 4249 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 4250 | res = ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4251 | this.name = name; |
| 4252 | this.len = strlen(name); |
| 4253 | this.hash = 0; /* will go */ |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 4254 | sb = shm_mnt->mnt_sb; |
Konstantin Khlebnikov | 66ee4b8 | 2014-08-06 16:06:32 -0700 | [diff] [blame] | 4255 | path.mnt = mntget(shm_mnt); |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 4256 | path.dentry = d_alloc_pseudo(sb, &this); |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 4257 | if (!path.dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4258 | goto put_memory; |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 4259 | d_set_d_op(path.dentry, &anon_ops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4260 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 4261 | res = ERR_PTR(-ENOSPC); |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 4262 | inode = shmem_get_inode(sb, NULL, S_IFREG | S_IRWXUGO, 0, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4263 | if (!inode) |
Konstantin Khlebnikov | 66ee4b8 | 2014-08-06 16:06:32 -0700 | [diff] [blame] | 4264 | goto put_memory; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4265 | |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 4266 | inode->i_flags |= i_flags; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 4267 | d_instantiate(path.dentry, inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4268 | inode->i_size = size; |
Miklos Szeredi | 6d6b77f | 2011-10-28 14:13:28 +0200 | [diff] [blame] | 4269 | clear_nlink(inode); /* It is unlinked */ |
Al Viro | 26567cd | 2013-03-01 20:22:53 -0500 | [diff] [blame] | 4270 | res = ERR_PTR(ramfs_nommu_expand_for_mapping(inode, size)); |
| 4271 | if (IS_ERR(res)) |
Konstantin Khlebnikov | 66ee4b8 | 2014-08-06 16:06:32 -0700 | [diff] [blame] | 4272 | goto put_path; |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 4273 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 4274 | res = alloc_file(&path, FMODE_WRITE | FMODE_READ, |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 4275 | &shmem_file_operations); |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 4276 | if (IS_ERR(res)) |
Konstantin Khlebnikov | 66ee4b8 | 2014-08-06 16:06:32 -0700 | [diff] [blame] | 4277 | goto put_path; |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 4278 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 4279 | return res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4280 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4281 | put_memory: |
| 4282 | shmem_unacct_size(flags, size); |
Konstantin Khlebnikov | 66ee4b8 | 2014-08-06 16:06:32 -0700 | [diff] [blame] | 4283 | put_path: |
| 4284 | path_put(&path); |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 4285 | return res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4286 | } |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 4287 | |
| 4288 | /** |
| 4289 | * shmem_kernel_file_setup - get an unlinked file living in tmpfs which must be |
| 4290 | * kernel internal. There will be NO LSM permission checks against the |
| 4291 | * underlying inode. So users of this interface must do LSM checks at a |
Stephen Smalley | e1832f2 | 2015-08-06 15:46:55 -0700 | [diff] [blame] | 4292 | * higher layer. The users are the big_key and shm implementations. LSM |
| 4293 | * checks are provided at the key or shm level rather than the inode. |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 4294 | * @name: name for dentry (to be seen in /proc/<pid>/maps |
| 4295 | * @size: size to be set for the file |
| 4296 | * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size |
| 4297 | */ |
| 4298 | struct file *shmem_kernel_file_setup(const char *name, loff_t size, unsigned long flags) |
| 4299 | { |
| 4300 | return __shmem_file_setup(name, size, flags, S_PRIVATE); |
| 4301 | } |
| 4302 | |
| 4303 | /** |
| 4304 | * shmem_file_setup - get an unlinked file living in tmpfs |
| 4305 | * @name: name for dentry (to be seen in /proc/<pid>/maps |
| 4306 | * @size: size to be set for the file |
| 4307 | * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size |
| 4308 | */ |
| 4309 | struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags) |
| 4310 | { |
| 4311 | return __shmem_file_setup(name, size, flags, 0); |
| 4312 | } |
Keith Packard | 395e0dd | 2008-06-20 00:08:06 -0700 | [diff] [blame] | 4313 | EXPORT_SYMBOL_GPL(shmem_file_setup); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4314 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 4315 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4316 | * shmem_zero_setup - setup a shared anonymous mapping |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4317 | * @vma: the vma to be mmapped is prepared by do_mmap_pgoff |
| 4318 | */ |
| 4319 | int shmem_zero_setup(struct vm_area_struct *vma) |
| 4320 | { |
| 4321 | struct file *file; |
| 4322 | loff_t size = vma->vm_end - vma->vm_start; |
| 4323 | |
Hugh Dickins | 66fc130 | 2015-06-14 09:48:09 -0700 | [diff] [blame] | 4324 | /* |
| 4325 | * Cloning a new file under mmap_sem leads to a lock ordering conflict |
| 4326 | * between XFS directory reading and selinux: since this file is only |
| 4327 | * accessible to the user through its mapping, use S_PRIVATE flag to |
| 4328 | * bypass file security, in the same way as shmem_kernel_file_setup(). |
| 4329 | */ |
| 4330 | file = __shmem_file_setup("dev/zero", size, vma->vm_flags, S_PRIVATE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4331 | if (IS_ERR(file)) |
| 4332 | return PTR_ERR(file); |
| 4333 | |
| 4334 | if (vma->vm_file) |
| 4335 | fput(vma->vm_file); |
| 4336 | vma->vm_file = file; |
| 4337 | vma->vm_ops = &shmem_vm_ops; |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 4338 | |
Kirill A. Shutemov | e496cf3 | 2016-07-26 15:26:35 -0700 | [diff] [blame] | 4339 | if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE) && |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 4340 | ((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) < |
| 4341 | (vma->vm_end & HPAGE_PMD_MASK)) { |
| 4342 | khugepaged_enter(vma, vma->vm_flags); |
| 4343 | } |
| 4344 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4345 | return 0; |
| 4346 | } |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 4347 | |
| 4348 | /** |
| 4349 | * shmem_read_mapping_page_gfp - read into page cache, using specified page allocation flags. |
| 4350 | * @mapping: the page's address_space |
| 4351 | * @index: the page index |
| 4352 | * @gfp: the page allocator flags to use if allocating |
| 4353 | * |
| 4354 | * This behaves as a tmpfs "read_cache_page_gfp(mapping, index, gfp)", |
| 4355 | * with any new page allocations done using the specified allocation flags. |
| 4356 | * But read_cache_page_gfp() uses the ->readpage() method: which does not |
| 4357 | * suit tmpfs, since it may have pages in swapcache, and needs to find those |
| 4358 | * for itself; although drivers/gpu/drm i915 and ttm rely upon this support. |
| 4359 | * |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4360 | * i915_gem_object_get_pages_gtt() mixes __GFP_NORETRY | __GFP_NOWARN in |
| 4361 | * with the mapping_gfp_mask(), to avoid OOMing the machine unnecessarily. |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 4362 | */ |
| 4363 | struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, |
| 4364 | pgoff_t index, gfp_t gfp) |
| 4365 | { |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4366 | #ifdef CONFIG_SHMEM |
| 4367 | struct inode *inode = mapping->host; |
Hugh Dickins | 9276aad | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4368 | struct page *page; |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4369 | int error; |
| 4370 | |
| 4371 | BUG_ON(mapping->a_ops != &shmem_aops); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 4372 | error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE, |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 4373 | gfp, NULL, NULL, NULL); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4374 | if (error) |
| 4375 | page = ERR_PTR(error); |
| 4376 | else |
| 4377 | unlock_page(page); |
| 4378 | return page; |
| 4379 | #else |
| 4380 | /* |
| 4381 | * The tiny !SHMEM case uses ramfs without swap |
| 4382 | */ |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 4383 | return read_cache_page_gfp(mapping, index, gfp); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4384 | #endif |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 4385 | } |
| 4386 | EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp); |