| /* -*- mode: c; c-basic-offset: 8; -*- |
| * vim: noexpandtab sw=8 ts=8 sts=0: |
| * |
| * dlmfs.c |
| * |
| * Code which implements the kernel side of a minimal userspace |
| * interface to our DLM. This file handles the virtual file system |
| * used for communication with userspace. Credit should go to ramfs, |
| * which was a template for the fs side of this module. |
| * |
| * Copyright (C) 2003, 2004 Oracle. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| /* Simple VFS hooks based on: */ |
| /* |
| * Resizable simple ram filesystem for Linux. |
| * |
| * Copyright (C) 2000 Linus Torvalds. |
| * 2000 Transmeta Corp. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <linux/pagemap.h> |
| #include <linux/types.h> |
| #include <linux/slab.h> |
| #include <linux/highmem.h> |
| #include <linux/init.h> |
| #include <linux/string.h> |
| #include <linux/smp_lock.h> |
| #include <linux/backing-dev.h> |
| |
| #include <asm/uaccess.h> |
| |
| |
| #include "cluster/nodemanager.h" |
| #include "cluster/heartbeat.h" |
| #include "cluster/tcp.h" |
| |
| #include "dlmapi.h" |
| |
| #include "userdlm.h" |
| |
| #include "dlmfsver.h" |
| |
| #define MLOG_MASK_PREFIX ML_DLMFS |
| #include "cluster/masklog.h" |
| |
| static struct super_operations dlmfs_ops; |
| static struct file_operations dlmfs_file_operations; |
| static struct inode_operations dlmfs_dir_inode_operations; |
| static struct inode_operations dlmfs_root_inode_operations; |
| static struct inode_operations dlmfs_file_inode_operations; |
| static kmem_cache_t *dlmfs_inode_cache; |
| |
| struct workqueue_struct *user_dlm_worker; |
| |
| /* |
| * decodes a set of open flags into a valid lock level and a set of flags. |
| * returns < 0 if we have invalid flags |
| * flags which mean something to us: |
| * O_RDONLY -> PRMODE level |
| * O_WRONLY -> EXMODE level |
| * |
| * O_NONBLOCK -> LKM_NOQUEUE |
| */ |
| static int dlmfs_decode_open_flags(int open_flags, |
| int *level, |
| int *flags) |
| { |
| if (open_flags & (O_WRONLY|O_RDWR)) |
| *level = LKM_EXMODE; |
| else |
| *level = LKM_PRMODE; |
| |
| *flags = 0; |
| if (open_flags & O_NONBLOCK) |
| *flags |= LKM_NOQUEUE; |
| |
| return 0; |
| } |
| |
| static int dlmfs_file_open(struct inode *inode, |
| struct file *file) |
| { |
| int status, level, flags; |
| struct dlmfs_filp_private *fp = NULL; |
| struct dlmfs_inode_private *ip; |
| |
| if (S_ISDIR(inode->i_mode)) |
| BUG(); |
| |
| mlog(0, "open called on inode %lu, flags 0x%x\n", inode->i_ino, |
| file->f_flags); |
| |
| status = dlmfs_decode_open_flags(file->f_flags, &level, &flags); |
| if (status < 0) |
| goto bail; |
| |
| /* We don't want to honor O_APPEND at read/write time as it |
| * doesn't make sense for LVB writes. */ |
| file->f_flags &= ~O_APPEND; |
| |
| fp = kmalloc(sizeof(*fp), GFP_NOFS); |
| if (!fp) { |
| status = -ENOMEM; |
| goto bail; |
| } |
| fp->fp_lock_level = level; |
| |
| ip = DLMFS_I(inode); |
| |
| status = user_dlm_cluster_lock(&ip->ip_lockres, level, flags); |
| if (status < 0) { |
| /* this is a strange error to return here but I want |
| * to be able userspace to be able to distinguish a |
| * valid lock request from one that simply couldn't be |
| * granted. */ |
| if (flags & LKM_NOQUEUE && status == -EAGAIN) |
| status = -ETXTBSY; |
| kfree(fp); |
| goto bail; |
| } |
| |
| file->private_data = fp; |
| bail: |
| return status; |
| } |
| |
| static int dlmfs_file_release(struct inode *inode, |
| struct file *file) |
| { |
| int level, status; |
| struct dlmfs_inode_private *ip = DLMFS_I(inode); |
| struct dlmfs_filp_private *fp = |
| (struct dlmfs_filp_private *) file->private_data; |
| |
| if (S_ISDIR(inode->i_mode)) |
| BUG(); |
| |
| mlog(0, "close called on inode %lu\n", inode->i_ino); |
| |
| status = 0; |
| if (fp) { |
| level = fp->fp_lock_level; |
| if (level != LKM_IVMODE) |
| user_dlm_cluster_unlock(&ip->ip_lockres, level); |
| |
| kfree(fp); |
| file->private_data = NULL; |
| } |
| |
| return 0; |
| } |
| |
| static ssize_t dlmfs_file_read(struct file *filp, |
| char __user *buf, |
| size_t count, |
| loff_t *ppos) |
| { |
| int bytes_left; |
| ssize_t readlen; |
| char *lvb_buf; |
| struct inode *inode = filp->f_dentry->d_inode; |
| |
| mlog(0, "inode %lu, count = %zu, *ppos = %llu\n", |
| inode->i_ino, count, *ppos); |
| |
| if (*ppos >= i_size_read(inode)) |
| return 0; |
| |
| if (!count) |
| return 0; |
| |
| if (!access_ok(VERIFY_WRITE, buf, count)) |
| return -EFAULT; |
| |
| /* don't read past the lvb */ |
| if ((count + *ppos) > i_size_read(inode)) |
| readlen = i_size_read(inode) - *ppos; |
| else |
| readlen = count - *ppos; |
| |
| lvb_buf = kmalloc(readlen, GFP_NOFS); |
| if (!lvb_buf) |
| return -ENOMEM; |
| |
| user_dlm_read_lvb(inode, lvb_buf, readlen); |
| bytes_left = __copy_to_user(buf, lvb_buf, readlen); |
| readlen -= bytes_left; |
| |
| kfree(lvb_buf); |
| |
| *ppos = *ppos + readlen; |
| |
| mlog(0, "read %zd bytes\n", readlen); |
| return readlen; |
| } |
| |
| static ssize_t dlmfs_file_write(struct file *filp, |
| const char __user *buf, |
| size_t count, |
| loff_t *ppos) |
| { |
| int bytes_left; |
| ssize_t writelen; |
| char *lvb_buf; |
| struct inode *inode = filp->f_dentry->d_inode; |
| |
| mlog(0, "inode %lu, count = %zu, *ppos = %llu\n", |
| inode->i_ino, count, *ppos); |
| |
| if (*ppos >= i_size_read(inode)) |
| return -ENOSPC; |
| |
| if (!count) |
| return 0; |
| |
| if (!access_ok(VERIFY_READ, buf, count)) |
| return -EFAULT; |
| |
| /* don't write past the lvb */ |
| if ((count + *ppos) > i_size_read(inode)) |
| writelen = i_size_read(inode) - *ppos; |
| else |
| writelen = count - *ppos; |
| |
| lvb_buf = kmalloc(writelen, GFP_NOFS); |
| if (!lvb_buf) |
| return -ENOMEM; |
| |
| bytes_left = copy_from_user(lvb_buf, buf, writelen); |
| writelen -= bytes_left; |
| if (writelen) |
| user_dlm_write_lvb(inode, lvb_buf, writelen); |
| |
| kfree(lvb_buf); |
| |
| *ppos = *ppos + writelen; |
| mlog(0, "wrote %zd bytes\n", writelen); |
| return writelen; |
| } |
| |
| static void dlmfs_init_once(void *foo, |
| kmem_cache_t *cachep, |
| unsigned long flags) |
| { |
| struct dlmfs_inode_private *ip = |
| (struct dlmfs_inode_private *) foo; |
| |
| if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == |
| SLAB_CTOR_CONSTRUCTOR) { |
| ip->ip_dlm = NULL; |
| ip->ip_parent = NULL; |
| |
| inode_init_once(&ip->ip_vfs_inode); |
| } |
| } |
| |
| static struct inode *dlmfs_alloc_inode(struct super_block *sb) |
| { |
| struct dlmfs_inode_private *ip; |
| |
| ip = kmem_cache_alloc(dlmfs_inode_cache, GFP_NOFS); |
| if (!ip) |
| return NULL; |
| |
| return &ip->ip_vfs_inode; |
| } |
| |
| static void dlmfs_destroy_inode(struct inode *inode) |
| { |
| kmem_cache_free(dlmfs_inode_cache, DLMFS_I(inode)); |
| } |
| |
| static void dlmfs_clear_inode(struct inode *inode) |
| { |
| int status; |
| struct dlmfs_inode_private *ip; |
| |
| if (!inode) |
| return; |
| |
| mlog(0, "inode %lu\n", inode->i_ino); |
| |
| ip = DLMFS_I(inode); |
| |
| if (S_ISREG(inode->i_mode)) { |
| status = user_dlm_destroy_lock(&ip->ip_lockres); |
| if (status < 0) |
| mlog_errno(status); |
| iput(ip->ip_parent); |
| goto clear_fields; |
| } |
| |
| mlog(0, "we're a directory, ip->ip_dlm = 0x%p\n", ip->ip_dlm); |
| /* we must be a directory. If required, lets unregister the |
| * dlm context now. */ |
| if (ip->ip_dlm) |
| user_dlm_unregister_context(ip->ip_dlm); |
| clear_fields: |
| ip->ip_parent = NULL; |
| ip->ip_dlm = NULL; |
| } |
| |
| static struct backing_dev_info dlmfs_backing_dev_info = { |
| .ra_pages = 0, /* No readahead */ |
| .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, |
| }; |
| |
| static struct inode *dlmfs_get_root_inode(struct super_block *sb) |
| { |
| struct inode *inode = new_inode(sb); |
| int mode = S_IFDIR | 0755; |
| struct dlmfs_inode_private *ip; |
| |
| if (inode) { |
| ip = DLMFS_I(inode); |
| |
| inode->i_mode = mode; |
| inode->i_uid = current->fsuid; |
| inode->i_gid = current->fsgid; |
| inode->i_blocks = 0; |
| inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info; |
| inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| inc_nlink(inode); |
| |
| inode->i_fop = &simple_dir_operations; |
| inode->i_op = &dlmfs_root_inode_operations; |
| } |
| |
| return inode; |
| } |
| |
| static struct inode *dlmfs_get_inode(struct inode *parent, |
| struct dentry *dentry, |
| int mode) |
| { |
| struct super_block *sb = parent->i_sb; |
| struct inode * inode = new_inode(sb); |
| struct dlmfs_inode_private *ip; |
| |
| if (!inode) |
| return NULL; |
| |
| inode->i_mode = mode; |
| inode->i_uid = current->fsuid; |
| inode->i_gid = current->fsgid; |
| inode->i_blocks = 0; |
| inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info; |
| inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| |
| ip = DLMFS_I(inode); |
| ip->ip_dlm = DLMFS_I(parent)->ip_dlm; |
| |
| switch (mode & S_IFMT) { |
| default: |
| /* for now we don't support anything other than |
| * directories and regular files. */ |
| BUG(); |
| break; |
| case S_IFREG: |
| inode->i_op = &dlmfs_file_inode_operations; |
| inode->i_fop = &dlmfs_file_operations; |
| |
| i_size_write(inode, DLM_LVB_LEN); |
| |
| user_dlm_lock_res_init(&ip->ip_lockres, dentry); |
| |
| /* released at clear_inode time, this insures that we |
| * get to drop the dlm reference on each lock *before* |
| * we call the unregister code for releasing parent |
| * directories. */ |
| ip->ip_parent = igrab(parent); |
| BUG_ON(!ip->ip_parent); |
| break; |
| case S_IFDIR: |
| inode->i_op = &dlmfs_dir_inode_operations; |
| inode->i_fop = &simple_dir_operations; |
| |
| /* directory inodes start off with i_nlink == |
| * 2 (for "." entry) */ |
| inc_nlink(inode); |
| break; |
| } |
| |
| if (parent->i_mode & S_ISGID) { |
| inode->i_gid = parent->i_gid; |
| if (S_ISDIR(mode)) |
| inode->i_mode |= S_ISGID; |
| } |
| |
| return inode; |
| } |
| |
| /* |
| * File creation. Allocate an inode, and we're done.. |
| */ |
| /* SMP-safe */ |
| static int dlmfs_mkdir(struct inode * dir, |
| struct dentry * dentry, |
| int mode) |
| { |
| int status; |
| struct inode *inode = NULL; |
| struct qstr *domain = &dentry->d_name; |
| struct dlmfs_inode_private *ip; |
| struct dlm_ctxt *dlm; |
| |
| mlog(0, "mkdir %.*s\n", domain->len, domain->name); |
| |
| /* verify that we have a proper domain */ |
| if (domain->len >= O2NM_MAX_NAME_LEN) { |
| status = -EINVAL; |
| mlog(ML_ERROR, "invalid domain name for directory.\n"); |
| goto bail; |
| } |
| |
| inode = dlmfs_get_inode(dir, dentry, mode | S_IFDIR); |
| if (!inode) { |
| status = -ENOMEM; |
| mlog_errno(status); |
| goto bail; |
| } |
| |
| ip = DLMFS_I(inode); |
| |
| dlm = user_dlm_register_context(domain); |
| if (IS_ERR(dlm)) { |
| status = PTR_ERR(dlm); |
| mlog(ML_ERROR, "Error %d could not register domain \"%.*s\"\n", |
| status, domain->len, domain->name); |
| goto bail; |
| } |
| ip->ip_dlm = dlm; |
| |
| inc_nlink(dir); |
| d_instantiate(dentry, inode); |
| dget(dentry); /* Extra count - pin the dentry in core */ |
| |
| status = 0; |
| bail: |
| if (status < 0) |
| iput(inode); |
| return status; |
| } |
| |
| static int dlmfs_create(struct inode *dir, |
| struct dentry *dentry, |
| int mode, |
| struct nameidata *nd) |
| { |
| int status = 0; |
| struct inode *inode; |
| struct qstr *name = &dentry->d_name; |
| |
| mlog(0, "create %.*s\n", name->len, name->name); |
| |
| /* verify name is valid and doesn't contain any dlm reserved |
| * characters */ |
| if (name->len >= USER_DLM_LOCK_ID_MAX_LEN || |
| name->name[0] == '$') { |
| status = -EINVAL; |
| mlog(ML_ERROR, "invalid lock name, %.*s\n", name->len, |
| name->name); |
| goto bail; |
| } |
| |
| inode = dlmfs_get_inode(dir, dentry, mode | S_IFREG); |
| if (!inode) { |
| status = -ENOMEM; |
| mlog_errno(status); |
| goto bail; |
| } |
| |
| d_instantiate(dentry, inode); |
| dget(dentry); /* Extra count - pin the dentry in core */ |
| bail: |
| return status; |
| } |
| |
| static int dlmfs_unlink(struct inode *dir, |
| struct dentry *dentry) |
| { |
| int status; |
| struct inode *inode = dentry->d_inode; |
| |
| mlog(0, "unlink inode %lu\n", inode->i_ino); |
| |
| /* if there are no current holders, or none that are waiting |
| * to acquire a lock, this basically destroys our lockres. */ |
| status = user_dlm_destroy_lock(&DLMFS_I(inode)->ip_lockres); |
| if (status < 0) { |
| mlog(ML_ERROR, "unlink %.*s, error %d from destroy\n", |
| dentry->d_name.len, dentry->d_name.name, status); |
| goto bail; |
| } |
| status = simple_unlink(dir, dentry); |
| bail: |
| return status; |
| } |
| |
| static int dlmfs_fill_super(struct super_block * sb, |
| void * data, |
| int silent) |
| { |
| struct inode * inode; |
| struct dentry * root; |
| |
| sb->s_maxbytes = MAX_LFS_FILESIZE; |
| sb->s_blocksize = PAGE_CACHE_SIZE; |
| sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| sb->s_magic = DLMFS_MAGIC; |
| sb->s_op = &dlmfs_ops; |
| inode = dlmfs_get_root_inode(sb); |
| if (!inode) |
| return -ENOMEM; |
| |
| root = d_alloc_root(inode); |
| if (!root) { |
| iput(inode); |
| return -ENOMEM; |
| } |
| sb->s_root = root; |
| return 0; |
| } |
| |
| static struct file_operations dlmfs_file_operations = { |
| .open = dlmfs_file_open, |
| .release = dlmfs_file_release, |
| .read = dlmfs_file_read, |
| .write = dlmfs_file_write, |
| }; |
| |
| static struct inode_operations dlmfs_dir_inode_operations = { |
| .create = dlmfs_create, |
| .lookup = simple_lookup, |
| .unlink = dlmfs_unlink, |
| }; |
| |
| /* this way we can restrict mkdir to only the toplevel of the fs. */ |
| static struct inode_operations dlmfs_root_inode_operations = { |
| .lookup = simple_lookup, |
| .mkdir = dlmfs_mkdir, |
| .rmdir = simple_rmdir, |
| }; |
| |
| static struct super_operations dlmfs_ops = { |
| .statfs = simple_statfs, |
| .alloc_inode = dlmfs_alloc_inode, |
| .destroy_inode = dlmfs_destroy_inode, |
| .clear_inode = dlmfs_clear_inode, |
| .drop_inode = generic_delete_inode, |
| }; |
| |
| static struct inode_operations dlmfs_file_inode_operations = { |
| .getattr = simple_getattr, |
| }; |
| |
| static int dlmfs_get_sb(struct file_system_type *fs_type, |
| int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
| { |
| return get_sb_nodev(fs_type, flags, data, dlmfs_fill_super, mnt); |
| } |
| |
| static struct file_system_type dlmfs_fs_type = { |
| .owner = THIS_MODULE, |
| .name = "ocfs2_dlmfs", |
| .get_sb = dlmfs_get_sb, |
| .kill_sb = kill_litter_super, |
| }; |
| |
| static int __init init_dlmfs_fs(void) |
| { |
| int status; |
| int cleanup_inode = 0, cleanup_worker = 0; |
| |
| dlmfs_print_version(); |
| |
| dlmfs_inode_cache = kmem_cache_create("dlmfs_inode_cache", |
| sizeof(struct dlmfs_inode_private), |
| 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
| SLAB_MEM_SPREAD), |
| dlmfs_init_once, NULL); |
| if (!dlmfs_inode_cache) |
| return -ENOMEM; |
| cleanup_inode = 1; |
| |
| user_dlm_worker = create_singlethread_workqueue("user_dlm"); |
| if (!user_dlm_worker) { |
| status = -ENOMEM; |
| goto bail; |
| } |
| cleanup_worker = 1; |
| |
| status = register_filesystem(&dlmfs_fs_type); |
| bail: |
| if (status) { |
| if (cleanup_inode) |
| kmem_cache_destroy(dlmfs_inode_cache); |
| if (cleanup_worker) |
| destroy_workqueue(user_dlm_worker); |
| } else |
| printk("OCFS2 User DLM kernel interface loaded\n"); |
| return status; |
| } |
| |
| static void __exit exit_dlmfs_fs(void) |
| { |
| unregister_filesystem(&dlmfs_fs_type); |
| |
| flush_workqueue(user_dlm_worker); |
| destroy_workqueue(user_dlm_worker); |
| |
| kmem_cache_destroy(dlmfs_inode_cache); |
| } |
| |
| MODULE_AUTHOR("Oracle"); |
| MODULE_LICENSE("GPL"); |
| |
| module_init(init_dlmfs_fs) |
| module_exit(exit_dlmfs_fs) |