| /* |
| * Copyright (C) 2008 Red Hat. 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 v2 as published by the Free Software Foundation. |
| * |
| * 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. |
| */ |
| |
| #include <linux/pagemap.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/math64.h> |
| #include "ctree.h" |
| #include "free-space-cache.h" |
| #include "transaction.h" |
| #include "disk-io.h" |
| #include "extent_io.h" |
| #include "inode-map.h" |
| |
| #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8) |
| #define MAX_CACHE_BYTES_PER_GIG (32 * 1024) |
| |
| static int link_free_space(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info); |
| |
| static struct inode *__lookup_free_space_inode(struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 offset) |
| { |
| struct btrfs_key key; |
| struct btrfs_key location; |
| struct btrfs_disk_key disk_key; |
| struct btrfs_free_space_header *header; |
| struct extent_buffer *leaf; |
| struct inode *inode = NULL; |
| int ret; |
| |
| key.objectid = BTRFS_FREE_SPACE_OBJECTID; |
| key.offset = offset; |
| key.type = 0; |
| |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (ret < 0) |
| return ERR_PTR(ret); |
| if (ret > 0) { |
| btrfs_release_path(path); |
| return ERR_PTR(-ENOENT); |
| } |
| |
| leaf = path->nodes[0]; |
| header = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_free_space_header); |
| btrfs_free_space_key(leaf, header, &disk_key); |
| btrfs_disk_key_to_cpu(&location, &disk_key); |
| btrfs_release_path(path); |
| |
| inode = btrfs_iget(root->fs_info->sb, &location, root, NULL); |
| if (!inode) |
| return ERR_PTR(-ENOENT); |
| if (IS_ERR(inode)) |
| return inode; |
| if (is_bad_inode(inode)) { |
| iput(inode); |
| return ERR_PTR(-ENOENT); |
| } |
| |
| inode->i_mapping->flags &= ~__GFP_FS; |
| |
| return inode; |
| } |
| |
| struct inode *lookup_free_space_inode(struct btrfs_root *root, |
| struct btrfs_block_group_cache |
| *block_group, struct btrfs_path *path) |
| { |
| struct inode *inode = NULL; |
| |
| spin_lock(&block_group->lock); |
| if (block_group->inode) |
| inode = igrab(block_group->inode); |
| spin_unlock(&block_group->lock); |
| if (inode) |
| return inode; |
| |
| inode = __lookup_free_space_inode(root, path, |
| block_group->key.objectid); |
| if (IS_ERR(inode)) |
| return inode; |
| |
| spin_lock(&block_group->lock); |
| if (!root->fs_info->closing) { |
| block_group->inode = igrab(inode); |
| block_group->iref = 1; |
| } |
| spin_unlock(&block_group->lock); |
| |
| return inode; |
| } |
| |
| int __create_free_space_inode(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_path *path, u64 ino, u64 offset) |
| { |
| struct btrfs_key key; |
| struct btrfs_disk_key disk_key; |
| struct btrfs_free_space_header *header; |
| struct btrfs_inode_item *inode_item; |
| struct extent_buffer *leaf; |
| int ret; |
| |
| ret = btrfs_insert_empty_inode(trans, root, path, ino); |
| if (ret) |
| return ret; |
| |
| leaf = path->nodes[0]; |
| inode_item = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_inode_item); |
| btrfs_item_key(leaf, &disk_key, path->slots[0]); |
| memset_extent_buffer(leaf, 0, (unsigned long)inode_item, |
| sizeof(*inode_item)); |
| btrfs_set_inode_generation(leaf, inode_item, trans->transid); |
| btrfs_set_inode_size(leaf, inode_item, 0); |
| btrfs_set_inode_nbytes(leaf, inode_item, 0); |
| btrfs_set_inode_uid(leaf, inode_item, 0); |
| btrfs_set_inode_gid(leaf, inode_item, 0); |
| btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600); |
| btrfs_set_inode_flags(leaf, inode_item, BTRFS_INODE_NOCOMPRESS | |
| BTRFS_INODE_PREALLOC | BTRFS_INODE_NODATASUM); |
| btrfs_set_inode_nlink(leaf, inode_item, 1); |
| btrfs_set_inode_transid(leaf, inode_item, trans->transid); |
| btrfs_set_inode_block_group(leaf, inode_item, offset); |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(path); |
| |
| key.objectid = BTRFS_FREE_SPACE_OBJECTID; |
| key.offset = offset; |
| key.type = 0; |
| |
| ret = btrfs_insert_empty_item(trans, root, path, &key, |
| sizeof(struct btrfs_free_space_header)); |
| if (ret < 0) { |
| btrfs_release_path(path); |
| return ret; |
| } |
| leaf = path->nodes[0]; |
| header = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_free_space_header); |
| memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header)); |
| btrfs_set_free_space_key(leaf, header, &disk_key); |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(path); |
| |
| return 0; |
| } |
| |
| int create_free_space_inode(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path) |
| { |
| int ret; |
| u64 ino; |
| |
| ret = btrfs_find_free_objectid(root, &ino); |
| if (ret < 0) |
| return ret; |
| |
| return __create_free_space_inode(root, trans, path, ino, |
| block_group->key.objectid); |
| } |
| |
| int btrfs_truncate_free_space_cache(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_path *path, |
| struct inode *inode) |
| { |
| loff_t oldsize; |
| int ret = 0; |
| |
| trans->block_rsv = root->orphan_block_rsv; |
| ret = btrfs_block_rsv_check(trans, root, |
| root->orphan_block_rsv, |
| 0, 5); |
| if (ret) |
| return ret; |
| |
| oldsize = i_size_read(inode); |
| btrfs_i_size_write(inode, 0); |
| truncate_pagecache(inode, oldsize, 0); |
| |
| /* |
| * We don't need an orphan item because truncating the free space cache |
| * will never be split across transactions. |
| */ |
| ret = btrfs_truncate_inode_items(trans, root, inode, |
| 0, BTRFS_EXTENT_DATA_KEY); |
| if (ret) { |
| WARN_ON(1); |
| return ret; |
| } |
| |
| ret = btrfs_update_inode(trans, root, inode); |
| return ret; |
| } |
| |
| static int readahead_cache(struct inode *inode) |
| { |
| struct file_ra_state *ra; |
| unsigned long last_index; |
| |
| ra = kzalloc(sizeof(*ra), GFP_NOFS); |
| if (!ra) |
| return -ENOMEM; |
| |
| file_ra_state_init(ra, inode->i_mapping); |
| last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT; |
| |
| page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index); |
| |
| kfree(ra); |
| |
| return 0; |
| } |
| |
| int __load_free_space_cache(struct btrfs_root *root, struct inode *inode, |
| struct btrfs_free_space_ctl *ctl, |
| struct btrfs_path *path, u64 offset) |
| { |
| struct btrfs_free_space_header *header; |
| struct extent_buffer *leaf; |
| struct page *page; |
| u32 *checksums = NULL, *crc; |
| char *disk_crcs = NULL; |
| struct btrfs_key key; |
| struct list_head bitmaps; |
| u64 num_entries; |
| u64 num_bitmaps; |
| u64 generation; |
| u32 cur_crc = ~(u32)0; |
| pgoff_t index = 0; |
| unsigned long first_page_offset; |
| int num_checksums; |
| int ret = 0, ret2; |
| |
| INIT_LIST_HEAD(&bitmaps); |
| |
| /* Nothing in the space cache, goodbye */ |
| if (!i_size_read(inode)) |
| goto out; |
| |
| key.objectid = BTRFS_FREE_SPACE_OBJECTID; |
| key.offset = offset; |
| key.type = 0; |
| |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (ret < 0) |
| goto out; |
| else if (ret > 0) { |
| btrfs_release_path(path); |
| ret = 0; |
| goto out; |
| } |
| |
| ret = -1; |
| |
| leaf = path->nodes[0]; |
| header = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_free_space_header); |
| num_entries = btrfs_free_space_entries(leaf, header); |
| num_bitmaps = btrfs_free_space_bitmaps(leaf, header); |
| generation = btrfs_free_space_generation(leaf, header); |
| btrfs_release_path(path); |
| |
| if (BTRFS_I(inode)->generation != generation) { |
| printk(KERN_ERR "btrfs: free space inode generation (%llu) did" |
| " not match free space cache generation (%llu)\n", |
| (unsigned long long)BTRFS_I(inode)->generation, |
| (unsigned long long)generation); |
| goto out; |
| } |
| |
| if (!num_entries) |
| goto out; |
| |
| /* Setup everything for doing checksumming */ |
| num_checksums = i_size_read(inode) / PAGE_CACHE_SIZE; |
| checksums = crc = kzalloc(sizeof(u32) * num_checksums, GFP_NOFS); |
| if (!checksums) |
| goto out; |
| first_page_offset = (sizeof(u32) * num_checksums) + sizeof(u64); |
| disk_crcs = kzalloc(first_page_offset, GFP_NOFS); |
| if (!disk_crcs) |
| goto out; |
| |
| ret = readahead_cache(inode); |
| if (ret) |
| goto out; |
| |
| while (1) { |
| struct btrfs_free_space_entry *entry; |
| struct btrfs_free_space *e; |
| void *addr; |
| unsigned long offset = 0; |
| unsigned long start_offset = 0; |
| int need_loop = 0; |
| |
| if (!num_entries && !num_bitmaps) |
| break; |
| |
| if (index == 0) { |
| start_offset = first_page_offset; |
| offset = start_offset; |
| } |
| |
| page = grab_cache_page(inode->i_mapping, index); |
| if (!page) |
| goto free_cache; |
| |
| if (!PageUptodate(page)) { |
| btrfs_readpage(NULL, page); |
| lock_page(page); |
| if (!PageUptodate(page)) { |
| unlock_page(page); |
| page_cache_release(page); |
| printk(KERN_ERR "btrfs: error reading free " |
| "space cache\n"); |
| goto free_cache; |
| } |
| } |
| addr = kmap(page); |
| |
| if (index == 0) { |
| u64 *gen; |
| |
| memcpy(disk_crcs, addr, first_page_offset); |
| gen = addr + (sizeof(u32) * num_checksums); |
| if (*gen != BTRFS_I(inode)->generation) { |
| printk(KERN_ERR "btrfs: space cache generation" |
| " (%llu) does not match inode (%llu)\n", |
| (unsigned long long)*gen, |
| (unsigned long long) |
| BTRFS_I(inode)->generation); |
| kunmap(page); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| crc = (u32 *)disk_crcs; |
| } |
| entry = addr + start_offset; |
| |
| /* First lets check our crc before we do anything fun */ |
| cur_crc = ~(u32)0; |
| cur_crc = btrfs_csum_data(root, addr + start_offset, cur_crc, |
| PAGE_CACHE_SIZE - start_offset); |
| btrfs_csum_final(cur_crc, (char *)&cur_crc); |
| if (cur_crc != *crc) { |
| printk(KERN_ERR "btrfs: crc mismatch for page %lu\n", |
| index); |
| kunmap(page); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| crc++; |
| |
| while (1) { |
| if (!num_entries) |
| break; |
| |
| need_loop = 1; |
| e = kmem_cache_zalloc(btrfs_free_space_cachep, |
| GFP_NOFS); |
| if (!e) { |
| kunmap(page); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| |
| e->offset = le64_to_cpu(entry->offset); |
| e->bytes = le64_to_cpu(entry->bytes); |
| if (!e->bytes) { |
| kunmap(page); |
| kmem_cache_free(btrfs_free_space_cachep, e); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| |
| if (entry->type == BTRFS_FREE_SPACE_EXTENT) { |
| spin_lock(&ctl->tree_lock); |
| ret = link_free_space(ctl, e); |
| spin_unlock(&ctl->tree_lock); |
| if (ret) { |
| printk(KERN_ERR "Duplicate entries in " |
| "free space cache, dumping\n"); |
| kunmap(page); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| } else { |
| e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); |
| if (!e->bitmap) { |
| kunmap(page); |
| kmem_cache_free( |
| btrfs_free_space_cachep, e); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| spin_lock(&ctl->tree_lock); |
| ret2 = link_free_space(ctl, e); |
| ctl->total_bitmaps++; |
| ctl->op->recalc_thresholds(ctl); |
| spin_unlock(&ctl->tree_lock); |
| list_add_tail(&e->list, &bitmaps); |
| if (ret) { |
| printk(KERN_ERR "Duplicate entries in " |
| "free space cache, dumping\n"); |
| kunmap(page); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| } |
| |
| num_entries--; |
| offset += sizeof(struct btrfs_free_space_entry); |
| if (offset + sizeof(struct btrfs_free_space_entry) >= |
| PAGE_CACHE_SIZE) |
| break; |
| entry++; |
| } |
| |
| /* |
| * We read an entry out of this page, we need to move on to the |
| * next page. |
| */ |
| if (need_loop) { |
| kunmap(page); |
| goto next; |
| } |
| |
| /* |
| * We add the bitmaps at the end of the entries in order that |
| * the bitmap entries are added to the cache. |
| */ |
| e = list_entry(bitmaps.next, struct btrfs_free_space, list); |
| list_del_init(&e->list); |
| memcpy(e->bitmap, addr, PAGE_CACHE_SIZE); |
| kunmap(page); |
| num_bitmaps--; |
| next: |
| unlock_page(page); |
| page_cache_release(page); |
| index++; |
| } |
| |
| ret = 1; |
| out: |
| kfree(checksums); |
| kfree(disk_crcs); |
| return ret; |
| free_cache: |
| __btrfs_remove_free_space_cache(ctl); |
| goto out; |
| } |
| |
| int load_free_space_cache(struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct btrfs_root *root = fs_info->tree_root; |
| struct inode *inode; |
| struct btrfs_path *path; |
| int ret; |
| bool matched; |
| u64 used = btrfs_block_group_used(&block_group->item); |
| |
| /* |
| * If we're unmounting then just return, since this does a search on the |
| * normal root and not the commit root and we could deadlock. |
| */ |
| smp_mb(); |
| if (fs_info->closing) |
| return 0; |
| |
| /* |
| * If this block group has been marked to be cleared for one reason or |
| * another then we can't trust the on disk cache, so just return. |
| */ |
| spin_lock(&block_group->lock); |
| if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) { |
| spin_unlock(&block_group->lock); |
| return 0; |
| } |
| spin_unlock(&block_group->lock); |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return 0; |
| |
| inode = lookup_free_space_inode(root, block_group, path); |
| if (IS_ERR(inode)) { |
| btrfs_free_path(path); |
| return 0; |
| } |
| |
| ret = __load_free_space_cache(fs_info->tree_root, inode, ctl, |
| path, block_group->key.objectid); |
| btrfs_free_path(path); |
| if (ret <= 0) |
| goto out; |
| |
| spin_lock(&ctl->tree_lock); |
| matched = (ctl->free_space == (block_group->key.offset - used - |
| block_group->bytes_super)); |
| spin_unlock(&ctl->tree_lock); |
| |
| if (!matched) { |
| __btrfs_remove_free_space_cache(ctl); |
| printk(KERN_ERR "block group %llu has an wrong amount of free " |
| "space\n", block_group->key.objectid); |
| ret = -1; |
| } |
| out: |
| if (ret < 0) { |
| /* This cache is bogus, make sure it gets cleared */ |
| spin_lock(&block_group->lock); |
| block_group->disk_cache_state = BTRFS_DC_CLEAR; |
| spin_unlock(&block_group->lock); |
| ret = 0; |
| |
| printk(KERN_ERR "btrfs: failed to load free space cache " |
| "for block group %llu\n", block_group->key.objectid); |
| } |
| |
| iput(inode); |
| return ret; |
| } |
| |
| int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode, |
| struct btrfs_free_space_ctl *ctl, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_path *path, u64 offset) |
| { |
| struct btrfs_free_space_header *header; |
| struct extent_buffer *leaf; |
| struct rb_node *node; |
| struct list_head *pos, *n; |
| struct page **pages; |
| struct page *page; |
| struct extent_state *cached_state = NULL; |
| struct btrfs_free_cluster *cluster = NULL; |
| struct extent_io_tree *unpin = NULL; |
| struct list_head bitmap_list; |
| struct btrfs_key key; |
| u64 start, end, len; |
| u64 bytes = 0; |
| u32 *crc, *checksums; |
| unsigned long first_page_offset; |
| int index = 0, num_pages = 0; |
| int entries = 0; |
| int bitmaps = 0; |
| int ret = -1; |
| bool next_page = false; |
| bool out_of_space = false; |
| |
| INIT_LIST_HEAD(&bitmap_list); |
| |
| node = rb_first(&ctl->free_space_offset); |
| if (!node) |
| return 0; |
| |
| if (!i_size_read(inode)) |
| return -1; |
| |
| num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> |
| PAGE_CACHE_SHIFT; |
| |
| /* Since the first page has all of our checksums and our generation we |
| * need to calculate the offset into the page that we can start writing |
| * our entries. |
| */ |
| first_page_offset = (sizeof(u32) * num_pages) + sizeof(u64); |
| |
| filemap_write_and_wait(inode->i_mapping); |
| btrfs_wait_ordered_range(inode, inode->i_size & |
| ~(root->sectorsize - 1), (u64)-1); |
| |
| /* make sure we don't overflow that first page */ |
| if (first_page_offset + sizeof(struct btrfs_free_space_entry) >= PAGE_CACHE_SIZE) { |
| /* this is really the same as running out of space, where we also return 0 */ |
| printk(KERN_CRIT "Btrfs: free space cache was too big for the crc page\n"); |
| ret = 0; |
| goto out_update; |
| } |
| |
| /* We need a checksum per page. */ |
| crc = checksums = kzalloc(sizeof(u32) * num_pages, GFP_NOFS); |
| if (!crc) |
| return -1; |
| |
| pages = kzalloc(sizeof(struct page *) * num_pages, GFP_NOFS); |
| if (!pages) { |
| kfree(crc); |
| return -1; |
| } |
| |
| /* Get the cluster for this block_group if it exists */ |
| if (block_group && !list_empty(&block_group->cluster_list)) |
| cluster = list_entry(block_group->cluster_list.next, |
| struct btrfs_free_cluster, |
| block_group_list); |
| |
| /* |
| * We shouldn't have switched the pinned extents yet so this is the |
| * right one |
| */ |
| unpin = root->fs_info->pinned_extents; |
| |
| /* |
| * Lock all pages first so we can lock the extent safely. |
| * |
| * NOTE: Because we hold the ref the entire time we're going to write to |
| * the page find_get_page should never fail, so we don't do a check |
| * after find_get_page at this point. Just putting this here so people |
| * know and don't freak out. |
| */ |
| while (index < num_pages) { |
| page = grab_cache_page(inode->i_mapping, index); |
| if (!page) { |
| int i; |
| |
| for (i = 0; i < num_pages; i++) { |
| unlock_page(pages[i]); |
| page_cache_release(pages[i]); |
| } |
| goto out_free; |
| } |
| pages[index] = page; |
| index++; |
| } |
| |
| index = 0; |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1, |
| 0, &cached_state, GFP_NOFS); |
| |
| /* |
| * When searching for pinned extents, we need to start at our start |
| * offset. |
| */ |
| if (block_group) |
| start = block_group->key.objectid; |
| |
| /* Write out the extent entries */ |
| do { |
| struct btrfs_free_space_entry *entry; |
| void *addr; |
| unsigned long offset = 0; |
| unsigned long start_offset = 0; |
| |
| next_page = false; |
| |
| if (index == 0) { |
| start_offset = first_page_offset; |
| offset = start_offset; |
| } |
| |
| if (index >= num_pages) { |
| out_of_space = true; |
| break; |
| } |
| |
| page = pages[index]; |
| |
| addr = kmap(page); |
| entry = addr + start_offset; |
| |
| memset(addr, 0, PAGE_CACHE_SIZE); |
| while (node && !next_page) { |
| struct btrfs_free_space *e; |
| |
| e = rb_entry(node, struct btrfs_free_space, offset_index); |
| entries++; |
| |
| entry->offset = cpu_to_le64(e->offset); |
| entry->bytes = cpu_to_le64(e->bytes); |
| if (e->bitmap) { |
| entry->type = BTRFS_FREE_SPACE_BITMAP; |
| list_add_tail(&e->list, &bitmap_list); |
| bitmaps++; |
| } else { |
| entry->type = BTRFS_FREE_SPACE_EXTENT; |
| } |
| node = rb_next(node); |
| if (!node && cluster) { |
| node = rb_first(&cluster->root); |
| cluster = NULL; |
| } |
| offset += sizeof(struct btrfs_free_space_entry); |
| if (offset + sizeof(struct btrfs_free_space_entry) >= |
| PAGE_CACHE_SIZE) |
| next_page = true; |
| entry++; |
| } |
| |
| /* |
| * We want to add any pinned extents to our free space cache |
| * so we don't leak the space |
| */ |
| while (block_group && !next_page && |
| (start < block_group->key.objectid + |
| block_group->key.offset)) { |
| ret = find_first_extent_bit(unpin, start, &start, &end, |
| EXTENT_DIRTY); |
| if (ret) { |
| ret = 0; |
| break; |
| } |
| |
| /* This pinned extent is out of our range */ |
| if (start >= block_group->key.objectid + |
| block_group->key.offset) |
| break; |
| |
| len = block_group->key.objectid + |
| block_group->key.offset - start; |
| len = min(len, end + 1 - start); |
| |
| entries++; |
| entry->offset = cpu_to_le64(start); |
| entry->bytes = cpu_to_le64(len); |
| entry->type = BTRFS_FREE_SPACE_EXTENT; |
| |
| start = end + 1; |
| offset += sizeof(struct btrfs_free_space_entry); |
| if (offset + sizeof(struct btrfs_free_space_entry) >= |
| PAGE_CACHE_SIZE) |
| next_page = true; |
| entry++; |
| } |
| *crc = ~(u32)0; |
| *crc = btrfs_csum_data(root, addr + start_offset, *crc, |
| PAGE_CACHE_SIZE - start_offset); |
| kunmap(page); |
| |
| btrfs_csum_final(*crc, (char *)crc); |
| crc++; |
| |
| bytes += PAGE_CACHE_SIZE; |
| |
| index++; |
| } while (node || next_page); |
| |
| /* Write out the bitmaps */ |
| list_for_each_safe(pos, n, &bitmap_list) { |
| void *addr; |
| struct btrfs_free_space *entry = |
| list_entry(pos, struct btrfs_free_space, list); |
| |
| if (index >= num_pages) { |
| out_of_space = true; |
| break; |
| } |
| page = pages[index]; |
| |
| addr = kmap(page); |
| memcpy(addr, entry->bitmap, PAGE_CACHE_SIZE); |
| *crc = ~(u32)0; |
| *crc = btrfs_csum_data(root, addr, *crc, PAGE_CACHE_SIZE); |
| kunmap(page); |
| btrfs_csum_final(*crc, (char *)crc); |
| crc++; |
| bytes += PAGE_CACHE_SIZE; |
| |
| list_del_init(&entry->list); |
| index++; |
| } |
| |
| if (out_of_space) { |
| btrfs_drop_pages(pages, num_pages); |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0, |
| i_size_read(inode) - 1, &cached_state, |
| GFP_NOFS); |
| ret = 0; |
| goto out_free; |
| } |
| |
| /* Zero out the rest of the pages just to make sure */ |
| while (index < num_pages) { |
| void *addr; |
| |
| page = pages[index]; |
| addr = kmap(page); |
| memset(addr, 0, PAGE_CACHE_SIZE); |
| kunmap(page); |
| bytes += PAGE_CACHE_SIZE; |
| index++; |
| } |
| |
| /* Write the checksums and trans id to the first page */ |
| { |
| void *addr; |
| u64 *gen; |
| |
| page = pages[0]; |
| |
| addr = kmap(page); |
| memcpy(addr, checksums, sizeof(u32) * num_pages); |
| gen = addr + (sizeof(u32) * num_pages); |
| *gen = trans->transid; |
| kunmap(page); |
| } |
| |
| ret = btrfs_dirty_pages(root, inode, pages, num_pages, 0, |
| bytes, &cached_state); |
| btrfs_drop_pages(pages, num_pages); |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0, |
| i_size_read(inode) - 1, &cached_state, GFP_NOFS); |
| |
| if (ret) { |
| ret = 0; |
| goto out_free; |
| } |
| |
| BTRFS_I(inode)->generation = trans->transid; |
| |
| filemap_write_and_wait(inode->i_mapping); |
| |
| key.objectid = BTRFS_FREE_SPACE_OBJECTID; |
| key.offset = offset; |
| key.type = 0; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, 1, 1); |
| if (ret < 0) { |
| ret = -1; |
| clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1, |
| EXTENT_DIRTY | EXTENT_DELALLOC | |
| EXTENT_DO_ACCOUNTING, 0, 0, NULL, GFP_NOFS); |
| goto out_free; |
| } |
| leaf = path->nodes[0]; |
| if (ret > 0) { |
| struct btrfs_key found_key; |
| BUG_ON(!path->slots[0]); |
| path->slots[0]--; |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID || |
| found_key.offset != offset) { |
| ret = -1; |
| clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1, |
| EXTENT_DIRTY | EXTENT_DELALLOC | |
| EXTENT_DO_ACCOUNTING, 0, 0, NULL, |
| GFP_NOFS); |
| btrfs_release_path(path); |
| goto out_free; |
| } |
| } |
| header = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_free_space_header); |
| btrfs_set_free_space_entries(leaf, header, entries); |
| btrfs_set_free_space_bitmaps(leaf, header, bitmaps); |
| btrfs_set_free_space_generation(leaf, header, trans->transid); |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(path); |
| |
| ret = 1; |
| |
| out_free: |
| kfree(checksums); |
| kfree(pages); |
| |
| out_update: |
| if (ret != 1) { |
| invalidate_inode_pages2_range(inode->i_mapping, 0, index); |
| BTRFS_I(inode)->generation = 0; |
| } |
| btrfs_update_inode(trans, root, inode); |
| return ret; |
| } |
| |
| int btrfs_write_out_cache(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct inode *inode; |
| int ret = 0; |
| |
| root = root->fs_info->tree_root; |
| |
| spin_lock(&block_group->lock); |
| if (block_group->disk_cache_state < BTRFS_DC_SETUP) { |
| spin_unlock(&block_group->lock); |
| return 0; |
| } |
| spin_unlock(&block_group->lock); |
| |
| inode = lookup_free_space_inode(root, block_group, path); |
| if (IS_ERR(inode)) |
| return 0; |
| |
| ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans, |
| path, block_group->key.objectid); |
| if (ret < 0) { |
| spin_lock(&block_group->lock); |
| block_group->disk_cache_state = BTRFS_DC_ERROR; |
| spin_unlock(&block_group->lock); |
| ret = 0; |
| |
| printk(KERN_ERR "btrfs: failed to write free space cace " |
| "for block group %llu\n", block_group->key.objectid); |
| } |
| |
| iput(inode); |
| return ret; |
| } |
| |
| static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit, |
| u64 offset) |
| { |
| BUG_ON(offset < bitmap_start); |
| offset -= bitmap_start; |
| return (unsigned long)(div_u64(offset, unit)); |
| } |
| |
| static inline unsigned long bytes_to_bits(u64 bytes, u32 unit) |
| { |
| return (unsigned long)(div_u64(bytes, unit)); |
| } |
| |
| static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl, |
| u64 offset) |
| { |
| u64 bitmap_start; |
| u64 bytes_per_bitmap; |
| |
| bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit; |
| bitmap_start = offset - ctl->start; |
| bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap); |
| bitmap_start *= bytes_per_bitmap; |
| bitmap_start += ctl->start; |
| |
| return bitmap_start; |
| } |
| |
| static int tree_insert_offset(struct rb_root *root, u64 offset, |
| struct rb_node *node, int bitmap) |
| { |
| struct rb_node **p = &root->rb_node; |
| struct rb_node *parent = NULL; |
| struct btrfs_free_space *info; |
| |
| while (*p) { |
| parent = *p; |
| info = rb_entry(parent, struct btrfs_free_space, offset_index); |
| |
| if (offset < info->offset) { |
| p = &(*p)->rb_left; |
| } else if (offset > info->offset) { |
| p = &(*p)->rb_right; |
| } else { |
| /* |
| * we could have a bitmap entry and an extent entry |
| * share the same offset. If this is the case, we want |
| * the extent entry to always be found first if we do a |
| * linear search through the tree, since we want to have |
| * the quickest allocation time, and allocating from an |
| * extent is faster than allocating from a bitmap. So |
| * if we're inserting a bitmap and we find an entry at |
| * this offset, we want to go right, or after this entry |
| * logically. If we are inserting an extent and we've |
| * found a bitmap, we want to go left, or before |
| * logically. |
| */ |
| if (bitmap) { |
| if (info->bitmap) { |
| WARN_ON_ONCE(1); |
| return -EEXIST; |
| } |
| p = &(*p)->rb_right; |
| } else { |
| if (!info->bitmap) { |
| WARN_ON_ONCE(1); |
| return -EEXIST; |
| } |
| p = &(*p)->rb_left; |
| } |
| } |
| } |
| |
| rb_link_node(node, parent, p); |
| rb_insert_color(node, root); |
| |
| return 0; |
| } |
| |
| /* |
| * searches the tree for the given offset. |
| * |
| * fuzzy - If this is set, then we are trying to make an allocation, and we just |
| * want a section that has at least bytes size and comes at or after the given |
| * offset. |
| */ |
| static struct btrfs_free_space * |
| tree_search_offset(struct btrfs_free_space_ctl *ctl, |
| u64 offset, int bitmap_only, int fuzzy) |
| { |
| struct rb_node *n = ctl->free_space_offset.rb_node; |
| struct btrfs_free_space *entry, *prev = NULL; |
| |
| /* find entry that is closest to the 'offset' */ |
| while (1) { |
| if (!n) { |
| entry = NULL; |
| break; |
| } |
| |
| entry = rb_entry(n, struct btrfs_free_space, offset_index); |
| prev = entry; |
| |
| if (offset < entry->offset) |
| n = n->rb_left; |
| else if (offset > entry->offset) |
| n = n->rb_right; |
| else |
| break; |
| } |
| |
| if (bitmap_only) { |
| if (!entry) |
| return NULL; |
| if (entry->bitmap) |
| return entry; |
| |
| /* |
| * bitmap entry and extent entry may share same offset, |
| * in that case, bitmap entry comes after extent entry. |
| */ |
| n = rb_next(n); |
| if (!n) |
| return NULL; |
| entry = rb_entry(n, struct btrfs_free_space, offset_index); |
| if (entry->offset != offset) |
| return NULL; |
| |
| WARN_ON(!entry->bitmap); |
| return entry; |
| } else if (entry) { |
| if (entry->bitmap) { |
| /* |
| * if previous extent entry covers the offset, |
| * we should return it instead of the bitmap entry |
| */ |
| n = &entry->offset_index; |
| while (1) { |
| n = rb_prev(n); |
| if (!n) |
| break; |
| prev = rb_entry(n, struct btrfs_free_space, |
| offset_index); |
| if (!prev->bitmap) { |
| if (prev->offset + prev->bytes > offset) |
| entry = prev; |
| break; |
| } |
| } |
| } |
| return entry; |
| } |
| |
| if (!prev) |
| return NULL; |
| |
| /* find last entry before the 'offset' */ |
| entry = prev; |
| if (entry->offset > offset) { |
| n = rb_prev(&entry->offset_index); |
| if (n) { |
| entry = rb_entry(n, struct btrfs_free_space, |
| offset_index); |
| BUG_ON(entry->offset > offset); |
| } else { |
| if (fuzzy) |
| return entry; |
| else |
| return NULL; |
| } |
| } |
| |
| if (entry->bitmap) { |
| n = &entry->offset_index; |
| while (1) { |
| n = rb_prev(n); |
| if (!n) |
| break; |
| prev = rb_entry(n, struct btrfs_free_space, |
| offset_index); |
| if (!prev->bitmap) { |
| if (prev->offset + prev->bytes > offset) |
| return prev; |
| break; |
| } |
| } |
| if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset) |
| return entry; |
| } else if (entry->offset + entry->bytes > offset) |
| return entry; |
| |
| if (!fuzzy) |
| return NULL; |
| |
| while (1) { |
| if (entry->bitmap) { |
| if (entry->offset + BITS_PER_BITMAP * |
| ctl->unit > offset) |
| break; |
| } else { |
| if (entry->offset + entry->bytes > offset) |
| break; |
| } |
| |
| n = rb_next(&entry->offset_index); |
| if (!n) |
| return NULL; |
| entry = rb_entry(n, struct btrfs_free_space, offset_index); |
| } |
| return entry; |
| } |
| |
| static inline void |
| __unlink_free_space(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info) |
| { |
| rb_erase(&info->offset_index, &ctl->free_space_offset); |
| ctl->free_extents--; |
| } |
| |
| static void unlink_free_space(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info) |
| { |
| __unlink_free_space(ctl, info); |
| ctl->free_space -= info->bytes; |
| } |
| |
| static int link_free_space(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info) |
| { |
| int ret = 0; |
| |
| BUG_ON(!info->bitmap && !info->bytes); |
| ret = tree_insert_offset(&ctl->free_space_offset, info->offset, |
| &info->offset_index, (info->bitmap != NULL)); |
| if (ret) |
| return ret; |
| |
| ctl->free_space += info->bytes; |
| ctl->free_extents++; |
| return ret; |
| } |
| |
| static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl) |
| { |
| struct btrfs_block_group_cache *block_group = ctl->private; |
| u64 max_bytes; |
| u64 bitmap_bytes; |
| u64 extent_bytes; |
| u64 size = block_group->key.offset; |
| u64 bytes_per_bg = BITS_PER_BITMAP * block_group->sectorsize; |
| int max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg); |
| |
| BUG_ON(ctl->total_bitmaps > max_bitmaps); |
| |
| /* |
| * The goal is to keep the total amount of memory used per 1gb of space |
| * at or below 32k, so we need to adjust how much memory we allow to be |
| * used by extent based free space tracking |
| */ |
| if (size < 1024 * 1024 * 1024) |
| max_bytes = MAX_CACHE_BYTES_PER_GIG; |
| else |
| max_bytes = MAX_CACHE_BYTES_PER_GIG * |
| div64_u64(size, 1024 * 1024 * 1024); |
| |
| /* |
| * we want to account for 1 more bitmap than what we have so we can make |
| * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as |
| * we add more bitmaps. |
| */ |
| bitmap_bytes = (ctl->total_bitmaps + 1) * PAGE_CACHE_SIZE; |
| |
| if (bitmap_bytes >= max_bytes) { |
| ctl->extents_thresh = 0; |
| return; |
| } |
| |
| /* |
| * we want the extent entry threshold to always be at most 1/2 the maxw |
| * bytes we can have, or whatever is less than that. |
| */ |
| extent_bytes = max_bytes - bitmap_bytes; |
| extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2)); |
| |
| ctl->extents_thresh = |
| div64_u64(extent_bytes, (sizeof(struct btrfs_free_space))); |
| } |
| |
| static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info, u64 offset, |
| u64 bytes) |
| { |
| unsigned long start, count; |
| |
| start = offset_to_bit(info->offset, ctl->unit, offset); |
| count = bytes_to_bits(bytes, ctl->unit); |
| BUG_ON(start + count > BITS_PER_BITMAP); |
| |
| bitmap_clear(info->bitmap, start, count); |
| |
| info->bytes -= bytes; |
| ctl->free_space -= bytes; |
| } |
| |
| static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info, u64 offset, |
| u64 bytes) |
| { |
| unsigned long start, count; |
| |
| start = offset_to_bit(info->offset, ctl->unit, offset); |
| count = bytes_to_bits(bytes, ctl->unit); |
| BUG_ON(start + count > BITS_PER_BITMAP); |
| |
| bitmap_set(info->bitmap, start, count); |
| |
| info->bytes += bytes; |
| ctl->free_space += bytes; |
| } |
| |
| static int search_bitmap(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *bitmap_info, u64 *offset, |
| u64 *bytes) |
| { |
| unsigned long found_bits = 0; |
| unsigned long bits, i; |
| unsigned long next_zero; |
| |
| i = offset_to_bit(bitmap_info->offset, ctl->unit, |
| max_t(u64, *offset, bitmap_info->offset)); |
| bits = bytes_to_bits(*bytes, ctl->unit); |
| |
| for (i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i); |
| i < BITS_PER_BITMAP; |
| i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i + 1)) { |
| next_zero = find_next_zero_bit(bitmap_info->bitmap, |
| BITS_PER_BITMAP, i); |
| if ((next_zero - i) >= bits) { |
| found_bits = next_zero - i; |
| break; |
| } |
| i = next_zero; |
| } |
| |
| if (found_bits) { |
| *offset = (u64)(i * ctl->unit) + bitmap_info->offset; |
| *bytes = (u64)(found_bits) * ctl->unit; |
| return 0; |
| } |
| |
| return -1; |
| } |
| |
| static struct btrfs_free_space * |
| find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes) |
| { |
| struct btrfs_free_space *entry; |
| struct rb_node *node; |
| int ret; |
| |
| if (!ctl->free_space_offset.rb_node) |
| return NULL; |
| |
| entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1); |
| if (!entry) |
| return NULL; |
| |
| for (node = &entry->offset_index; node; node = rb_next(node)) { |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| if (entry->bytes < *bytes) |
| continue; |
| |
| if (entry->bitmap) { |
| ret = search_bitmap(ctl, entry, offset, bytes); |
| if (!ret) |
| return entry; |
| continue; |
| } |
| |
| *offset = entry->offset; |
| *bytes = entry->bytes; |
| return entry; |
| } |
| |
| return NULL; |
| } |
| |
| static void add_new_bitmap(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info, u64 offset) |
| { |
| info->offset = offset_to_bitmap(ctl, offset); |
| info->bytes = 0; |
| link_free_space(ctl, info); |
| ctl->total_bitmaps++; |
| |
| ctl->op->recalc_thresholds(ctl); |
| } |
| |
| static void free_bitmap(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *bitmap_info) |
| { |
| unlink_free_space(ctl, bitmap_info); |
| kfree(bitmap_info->bitmap); |
| kmem_cache_free(btrfs_free_space_cachep, bitmap_info); |
| ctl->total_bitmaps--; |
| ctl->op->recalc_thresholds(ctl); |
| } |
| |
| static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *bitmap_info, |
| u64 *offset, u64 *bytes) |
| { |
| u64 end; |
| u64 search_start, search_bytes; |
| int ret; |
| |
| again: |
| end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1; |
| |
| /* |
| * XXX - this can go away after a few releases. |
| * |
| * since the only user of btrfs_remove_free_space is the tree logging |
| * stuff, and the only way to test that is under crash conditions, we |
| * want to have this debug stuff here just in case somethings not |
| * working. Search the bitmap for the space we are trying to use to |
| * make sure its actually there. If its not there then we need to stop |
| * because something has gone wrong. |
| */ |
| search_start = *offset; |
| search_bytes = *bytes; |
| search_bytes = min(search_bytes, end - search_start + 1); |
| ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes); |
| BUG_ON(ret < 0 || search_start != *offset); |
| |
| if (*offset > bitmap_info->offset && *offset + *bytes > end) { |
| bitmap_clear_bits(ctl, bitmap_info, *offset, end - *offset + 1); |
| *bytes -= end - *offset + 1; |
| *offset = end + 1; |
| } else if (*offset >= bitmap_info->offset && *offset + *bytes <= end) { |
| bitmap_clear_bits(ctl, bitmap_info, *offset, *bytes); |
| *bytes = 0; |
| } |
| |
| if (*bytes) { |
| struct rb_node *next = rb_next(&bitmap_info->offset_index); |
| if (!bitmap_info->bytes) |
| free_bitmap(ctl, bitmap_info); |
| |
| /* |
| * no entry after this bitmap, but we still have bytes to |
| * remove, so something has gone wrong. |
| */ |
| if (!next) |
| return -EINVAL; |
| |
| bitmap_info = rb_entry(next, struct btrfs_free_space, |
| offset_index); |
| |
| /* |
| * if the next entry isn't a bitmap we need to return to let the |
| * extent stuff do its work. |
| */ |
| if (!bitmap_info->bitmap) |
| return -EAGAIN; |
| |
| /* |
| * Ok the next item is a bitmap, but it may not actually hold |
| * the information for the rest of this free space stuff, so |
| * look for it, and if we don't find it return so we can try |
| * everything over again. |
| */ |
| search_start = *offset; |
| search_bytes = *bytes; |
| ret = search_bitmap(ctl, bitmap_info, &search_start, |
| &search_bytes); |
| if (ret < 0 || search_start != *offset) |
| return -EAGAIN; |
| |
| goto again; |
| } else if (!bitmap_info->bytes) |
| free_bitmap(ctl, bitmap_info); |
| |
| return 0; |
| } |
| |
| static bool use_bitmap(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info) |
| { |
| struct btrfs_block_group_cache *block_group = ctl->private; |
| |
| /* |
| * If we are below the extents threshold then we can add this as an |
| * extent, and don't have to deal with the bitmap |
| */ |
| if (ctl->free_extents < ctl->extents_thresh) { |
| /* |
| * If this block group has some small extents we don't want to |
| * use up all of our free slots in the cache with them, we want |
| * to reserve them to larger extents, however if we have plent |
| * of cache left then go ahead an dadd them, no sense in adding |
| * the overhead of a bitmap if we don't have to. |
| */ |
| if (info->bytes <= block_group->sectorsize * 4) { |
| if (ctl->free_extents * 2 <= ctl->extents_thresh) |
| return false; |
| } else { |
| return false; |
| } |
| } |
| |
| /* |
| * some block groups are so tiny they can't be enveloped by a bitmap, so |
| * don't even bother to create a bitmap for this |
| */ |
| if (BITS_PER_BITMAP * block_group->sectorsize > |
| block_group->key.offset) |
| return false; |
| |
| return true; |
| } |
| |
| static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info) |
| { |
| struct btrfs_free_space *bitmap_info; |
| int added = 0; |
| u64 bytes, offset, end; |
| int ret; |
| |
| bytes = info->bytes; |
| offset = info->offset; |
| |
| if (!ctl->op->use_bitmap(ctl, info)) |
| return 0; |
| |
| again: |
| bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), |
| 1, 0); |
| if (!bitmap_info) { |
| BUG_ON(added); |
| goto new_bitmap; |
| } |
| |
| end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit); |
| |
| if (offset >= bitmap_info->offset && offset + bytes > end) { |
| bitmap_set_bits(ctl, bitmap_info, offset, end - offset); |
| bytes -= end - offset; |
| offset = end; |
| added = 0; |
| } else if (offset >= bitmap_info->offset && offset + bytes <= end) { |
| bitmap_set_bits(ctl, bitmap_info, offset, bytes); |
| bytes = 0; |
| } else { |
| BUG(); |
| } |
| |
| if (!bytes) { |
| ret = 1; |
| goto out; |
| } else |
| goto again; |
| |
| new_bitmap: |
| if (info && info->bitmap) { |
| add_new_bitmap(ctl, info, offset); |
| added = 1; |
| info = NULL; |
| goto again; |
| } else { |
| spin_unlock(&ctl->tree_lock); |
| |
| /* no pre-allocated info, allocate a new one */ |
| if (!info) { |
| info = kmem_cache_zalloc(btrfs_free_space_cachep, |
| GFP_NOFS); |
| if (!info) { |
| spin_lock(&ctl->tree_lock); |
| ret = -ENOMEM; |
| goto out; |
| } |
| } |
| |
| /* allocate the bitmap */ |
| info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); |
| spin_lock(&ctl->tree_lock); |
| if (!info->bitmap) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| goto again; |
| } |
| |
| out: |
| if (info) { |
| if (info->bitmap) |
| kfree(info->bitmap); |
| kmem_cache_free(btrfs_free_space_cachep, info); |
| } |
| |
| return ret; |
| } |
| |
| static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info, bool update_stat) |
| { |
| struct btrfs_free_space *left_info; |
| struct btrfs_free_space *right_info; |
| bool merged = false; |
| u64 offset = info->offset; |
| u64 bytes = info->bytes; |
| |
| /* |
| * first we want to see if there is free space adjacent to the range we |
| * are adding, if there is remove that struct and add a new one to |
| * cover the entire range |
| */ |
| right_info = tree_search_offset(ctl, offset + bytes, 0, 0); |
| if (right_info && rb_prev(&right_info->offset_index)) |
| left_info = rb_entry(rb_prev(&right_info->offset_index), |
| struct btrfs_free_space, offset_index); |
| else |
| left_info = tree_search_offset(ctl, offset - 1, 0, 0); |
| |
| if (right_info && !right_info->bitmap) { |
| if (update_stat) |
| unlink_free_space(ctl, right_info); |
| else |
| __unlink_free_space(ctl, right_info); |
| info->bytes += right_info->bytes; |
| kmem_cache_free(btrfs_free_space_cachep, right_info); |
| merged = true; |
| } |
| |
| if (left_info && !left_info->bitmap && |
| left_info->offset + left_info->bytes == offset) { |
| if (update_stat) |
| unlink_free_space(ctl, left_info); |
| else |
| __unlink_free_space(ctl, left_info); |
| info->offset = left_info->offset; |
| info->bytes += left_info->bytes; |
| kmem_cache_free(btrfs_free_space_cachep, left_info); |
| merged = true; |
| } |
| |
| return merged; |
| } |
| |
| int __btrfs_add_free_space(struct btrfs_free_space_ctl *ctl, |
| u64 offset, u64 bytes) |
| { |
| struct btrfs_free_space *info; |
| int ret = 0; |
| |
| info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS); |
| if (!info) |
| return -ENOMEM; |
| |
| info->offset = offset; |
| info->bytes = bytes; |
| |
| spin_lock(&ctl->tree_lock); |
| |
| if (try_merge_free_space(ctl, info, true)) |
| goto link; |
| |
| /* |
| * There was no extent directly to the left or right of this new |
| * extent then we know we're going to have to allocate a new extent, so |
| * before we do that see if we need to drop this into a bitmap |
| */ |
| ret = insert_into_bitmap(ctl, info); |
| if (ret < 0) { |
| goto out; |
| } else if (ret) { |
| ret = 0; |
| goto out; |
| } |
| link: |
| ret = link_free_space(ctl, info); |
| if (ret) |
| kmem_cache_free(btrfs_free_space_cachep, info); |
| out: |
| spin_unlock(&ctl->tree_lock); |
| |
| if (ret) { |
| printk(KERN_CRIT "btrfs: unable to add free space :%d\n", ret); |
| BUG_ON(ret == -EEXIST); |
| } |
| |
| return ret; |
| } |
| |
| int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group, |
| u64 offset, u64 bytes) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct btrfs_free_space *info; |
| struct btrfs_free_space *next_info = NULL; |
| int ret = 0; |
| |
| spin_lock(&ctl->tree_lock); |
| |
| again: |
| info = tree_search_offset(ctl, offset, 0, 0); |
| if (!info) { |
| /* |
| * oops didn't find an extent that matched the space we wanted |
| * to remove, look for a bitmap instead |
| */ |
| info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), |
| 1, 0); |
| if (!info) { |
| WARN_ON(1); |
| goto out_lock; |
| } |
| } |
| |
| if (info->bytes < bytes && rb_next(&info->offset_index)) { |
| u64 end; |
| next_info = rb_entry(rb_next(&info->offset_index), |
| struct btrfs_free_space, |
| offset_index); |
| |
| if (next_info->bitmap) |
| end = next_info->offset + |
| BITS_PER_BITMAP * ctl->unit - 1; |
| else |
| end = next_info->offset + next_info->bytes; |
| |
| if (next_info->bytes < bytes || |
| next_info->offset > offset || offset > end) { |
| printk(KERN_CRIT "Found free space at %llu, size %llu," |
| " trying to use %llu\n", |
| (unsigned long long)info->offset, |
| (unsigned long long)info->bytes, |
| (unsigned long long)bytes); |
| WARN_ON(1); |
| ret = -EINVAL; |
| goto out_lock; |
| } |
| |
| info = next_info; |
| } |
| |
| if (info->bytes == bytes) { |
| unlink_free_space(ctl, info); |
| if (info->bitmap) { |
| kfree(info->bitmap); |
| ctl->total_bitmaps--; |
| } |
| kmem_cache_free(btrfs_free_space_cachep, info); |
| goto out_lock; |
| } |
| |
| if (!info->bitmap && info->offset == offset) { |
| unlink_free_space(ctl, info); |
| info->offset += bytes; |
| info->bytes -= bytes; |
| link_free_space(ctl, info); |
| goto out_lock; |
| } |
| |
| if (!info->bitmap && info->offset <= offset && |
| info->offset + info->bytes >= offset + bytes) { |
| u64 old_start = info->offset; |
| /* |
| * we're freeing space in the middle of the info, |
| * this can happen during tree log replay |
| * |
| * first unlink the old info and then |
| * insert it again after the hole we're creating |
| */ |
| unlink_free_space(ctl, info); |
| if (offset + bytes < info->offset + info->bytes) { |
| u64 old_end = info->offset + info->bytes; |
| |
| info->offset = offset + bytes; |
| info->bytes = old_end - info->offset; |
| ret = link_free_space(ctl, info); |
| WARN_ON(ret); |
| if (ret) |
| goto out_lock; |
| } else { |
| /* the hole we're creating ends at the end |
| * of the info struct, just free the info |
| */ |
| kmem_cache_free(btrfs_free_space_cachep, info); |
| } |
| spin_unlock(&ctl->tree_lock); |
| |
| /* step two, insert a new info struct to cover |
| * anything before the hole |
| */ |
| ret = btrfs_add_free_space(block_group, old_start, |
| offset - old_start); |
| WARN_ON(ret); |
| goto out; |
| } |
| |
| ret = remove_from_bitmap(ctl, info, &offset, &bytes); |
| if (ret == -EAGAIN) |
| goto again; |
| BUG_ON(ret); |
| out_lock: |
| spin_unlock(&ctl->tree_lock); |
| out: |
| return ret; |
| } |
| |
| void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group, |
| u64 bytes) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct btrfs_free_space *info; |
| struct rb_node *n; |
| int count = 0; |
| |
| for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) { |
| info = rb_entry(n, struct btrfs_free_space, offset_index); |
| if (info->bytes >= bytes) |
| count++; |
| printk(KERN_CRIT "entry offset %llu, bytes %llu, bitmap %s\n", |
| (unsigned long long)info->offset, |
| (unsigned long long)info->bytes, |
| (info->bitmap) ? "yes" : "no"); |
| } |
| printk(KERN_INFO "block group has cluster?: %s\n", |
| list_empty(&block_group->cluster_list) ? "no" : "yes"); |
| printk(KERN_INFO "%d blocks of free space at or bigger than bytes is" |
| "\n", count); |
| } |
| |
| static struct btrfs_free_space_op free_space_op = { |
| .recalc_thresholds = recalculate_thresholds, |
| .use_bitmap = use_bitmap, |
| }; |
| |
| void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| |
| spin_lock_init(&ctl->tree_lock); |
| ctl->unit = block_group->sectorsize; |
| ctl->start = block_group->key.objectid; |
| ctl->private = block_group; |
| ctl->op = &free_space_op; |
| |
| /* |
| * we only want to have 32k of ram per block group for keeping |
| * track of free space, and if we pass 1/2 of that we want to |
| * start converting things over to using bitmaps |
| */ |
| ctl->extents_thresh = ((1024 * 32) / 2) / |
| sizeof(struct btrfs_free_space); |
| } |
| |
| /* |
| * for a given cluster, put all of its extents back into the free |
| * space cache. If the block group passed doesn't match the block group |
| * pointed to by the cluster, someone else raced in and freed the |
| * cluster already. In that case, we just return without changing anything |
| */ |
| static int |
| __btrfs_return_cluster_to_free_space( |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct btrfs_free_space *entry; |
| struct rb_node *node; |
| |
| spin_lock(&cluster->lock); |
| if (cluster->block_group != block_group) |
| goto out; |
| |
| cluster->block_group = NULL; |
| cluster->window_start = 0; |
| list_del_init(&cluster->block_group_list); |
| |
| node = rb_first(&cluster->root); |
| while (node) { |
| bool bitmap; |
| |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| node = rb_next(&entry->offset_index); |
| rb_erase(&entry->offset_index, &cluster->root); |
| |
| bitmap = (entry->bitmap != NULL); |
| if (!bitmap) |
| try_merge_free_space(ctl, entry, false); |
| tree_insert_offset(&ctl->free_space_offset, |
| entry->offset, &entry->offset_index, bitmap); |
| } |
| cluster->root = RB_ROOT; |
| |
| out: |
| spin_unlock(&cluster->lock); |
| btrfs_put_block_group(block_group); |
| return 0; |
| } |
| |
| void __btrfs_remove_free_space_cache_locked(struct btrfs_free_space_ctl *ctl) |
| { |
| struct btrfs_free_space *info; |
| struct rb_node *node; |
| |
| while ((node = rb_last(&ctl->free_space_offset)) != NULL) { |
| info = rb_entry(node, struct btrfs_free_space, offset_index); |
| unlink_free_space(ctl, info); |
| kfree(info->bitmap); |
| kmem_cache_free(btrfs_free_space_cachep, info); |
| if (need_resched()) { |
| spin_unlock(&ctl->tree_lock); |
| cond_resched(); |
| spin_lock(&ctl->tree_lock); |
| } |
| } |
| } |
| |
| void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl) |
| { |
| spin_lock(&ctl->tree_lock); |
| __btrfs_remove_free_space_cache_locked(ctl); |
| spin_unlock(&ctl->tree_lock); |
| } |
| |
| void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct btrfs_free_cluster *cluster; |
| struct list_head *head; |
| |
| spin_lock(&ctl->tree_lock); |
| while ((head = block_group->cluster_list.next) != |
| &block_group->cluster_list) { |
| cluster = list_entry(head, struct btrfs_free_cluster, |
| block_group_list); |
| |
| WARN_ON(cluster->block_group != block_group); |
| __btrfs_return_cluster_to_free_space(block_group, cluster); |
| if (need_resched()) { |
| spin_unlock(&ctl->tree_lock); |
| cond_resched(); |
| spin_lock(&ctl->tree_lock); |
| } |
| } |
| __btrfs_remove_free_space_cache_locked(ctl); |
| spin_unlock(&ctl->tree_lock); |
| |
| } |
| |
| u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group, |
| u64 offset, u64 bytes, u64 empty_size) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct btrfs_free_space *entry = NULL; |
| u64 bytes_search = bytes + empty_size; |
| u64 ret = 0; |
| |
| spin_lock(&ctl->tree_lock); |
| entry = find_free_space(ctl, &offset, &bytes_search); |
| if (!entry) |
| goto out; |
| |
| ret = offset; |
| if (entry->bitmap) { |
| bitmap_clear_bits(ctl, entry, offset, bytes); |
| if (!entry->bytes) |
| free_bitmap(ctl, entry); |
| } else { |
| unlink_free_space(ctl, entry); |
| entry->offset += bytes; |
| entry->bytes -= bytes; |
| if (!entry->bytes) |
| kmem_cache_free(btrfs_free_space_cachep, entry); |
| else |
| link_free_space(ctl, entry); |
| } |
| |
| out: |
| spin_unlock(&ctl->tree_lock); |
| |
| return ret; |
| } |
| |
| /* |
| * given a cluster, put all of its extents back into the free space |
| * cache. If a block group is passed, this function will only free |
| * a cluster that belongs to the passed block group. |
| * |
| * Otherwise, it'll get a reference on the block group pointed to by the |
| * cluster and remove the cluster from it. |
| */ |
| int btrfs_return_cluster_to_free_space( |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster) |
| { |
| struct btrfs_free_space_ctl *ctl; |
| int ret; |
| |
| /* first, get a safe pointer to the block group */ |
| spin_lock(&cluster->lock); |
| if (!block_group) { |
| block_group = cluster->block_group; |
| if (!block_group) { |
| spin_unlock(&cluster->lock); |
| return 0; |
| } |
| } else if (cluster->block_group != block_group) { |
| /* someone else has already freed it don't redo their work */ |
| spin_unlock(&cluster->lock); |
| return 0; |
| } |
| atomic_inc(&block_group->count); |
| spin_unlock(&cluster->lock); |
| |
| ctl = block_group->free_space_ctl; |
| |
| /* now return any extents the cluster had on it */ |
| spin_lock(&ctl->tree_lock); |
| ret = __btrfs_return_cluster_to_free_space(block_group, cluster); |
| spin_unlock(&ctl->tree_lock); |
| |
| /* finally drop our ref */ |
| btrfs_put_block_group(block_group); |
| return ret; |
| } |
| |
| static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster, |
| struct btrfs_free_space *entry, |
| u64 bytes, u64 min_start) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| int err; |
| u64 search_start = cluster->window_start; |
| u64 search_bytes = bytes; |
| u64 ret = 0; |
| |
| search_start = min_start; |
| search_bytes = bytes; |
| |
| err = search_bitmap(ctl, entry, &search_start, &search_bytes); |
| if (err) |
| return 0; |
| |
| ret = search_start; |
| bitmap_clear_bits(ctl, entry, ret, bytes); |
| |
| return ret; |
| } |
| |
| /* |
| * given a cluster, try to allocate 'bytes' from it, returns 0 |
| * if it couldn't find anything suitably large, or a logical disk offset |
| * if things worked out |
| */ |
| u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster, u64 bytes, |
| u64 min_start) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct btrfs_free_space *entry = NULL; |
| struct rb_node *node; |
| u64 ret = 0; |
| |
| spin_lock(&cluster->lock); |
| if (bytes > cluster->max_size) |
| goto out; |
| |
| if (cluster->block_group != block_group) |
| goto out; |
| |
| node = rb_first(&cluster->root); |
| if (!node) |
| goto out; |
| |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| while(1) { |
| if (entry->bytes < bytes || |
| (!entry->bitmap && entry->offset < min_start)) { |
| node = rb_next(&entry->offset_index); |
| if (!node) |
| break; |
| entry = rb_entry(node, struct btrfs_free_space, |
| offset_index); |
| continue; |
| } |
| |
| if (entry->bitmap) { |
| ret = btrfs_alloc_from_bitmap(block_group, |
| cluster, entry, bytes, |
| min_start); |
| if (ret == 0) { |
| node = rb_next(&entry->offset_index); |
| if (!node) |
| break; |
| entry = rb_entry(node, struct btrfs_free_space, |
| offset_index); |
| continue; |
| } |
| } else { |
| |
| ret = entry->offset; |
| |
| entry->offset += bytes; |
| entry->bytes -= bytes; |
| } |
| |
| if (entry->bytes == 0) |
| rb_erase(&entry->offset_index, &cluster->root); |
| break; |
| } |
| out: |
| spin_unlock(&cluster->lock); |
| |
| if (!ret) |
| return 0; |
| |
| spin_lock(&ctl->tree_lock); |
| |
| ctl->free_space -= bytes; |
| if (entry->bytes == 0) { |
| ctl->free_extents--; |
| if (entry->bitmap) { |
| kfree(entry->bitmap); |
| ctl->total_bitmaps--; |
| ctl->op->recalc_thresholds(ctl); |
| } |
| kmem_cache_free(btrfs_free_space_cachep, entry); |
| } |
| |
| spin_unlock(&ctl->tree_lock); |
| |
| return ret; |
| } |
| |
| static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *entry, |
| struct btrfs_free_cluster *cluster, |
| u64 offset, u64 bytes, u64 min_bytes) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| unsigned long next_zero; |
| unsigned long i; |
| unsigned long search_bits; |
| unsigned long total_bits; |
| unsigned long found_bits; |
| unsigned long start = 0; |
| unsigned long total_found = 0; |
| int ret; |
| bool found = false; |
| |
| i = offset_to_bit(entry->offset, block_group->sectorsize, |
| max_t(u64, offset, entry->offset)); |
| search_bits = bytes_to_bits(bytes, block_group->sectorsize); |
| total_bits = bytes_to_bits(min_bytes, block_group->sectorsize); |
| |
| again: |
| found_bits = 0; |
| for (i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i); |
| i < BITS_PER_BITMAP; |
| i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i + 1)) { |
| next_zero = find_next_zero_bit(entry->bitmap, |
| BITS_PER_BITMAP, i); |
| if (next_zero - i >= search_bits) { |
| found_bits = next_zero - i; |
| break; |
| } |
| i = next_zero; |
| } |
| |
| if (!found_bits) |
| return -ENOSPC; |
| |
| if (!found) { |
| start = i; |
| found = true; |
| } |
| |
| total_found += found_bits; |
| |
| if (cluster->max_size < found_bits * block_group->sectorsize) |
| cluster->max_size = found_bits * block_group->sectorsize; |
| |
| if (total_found < total_bits) { |
| i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, next_zero); |
| if (i - start > total_bits * 2) { |
| total_found = 0; |
| cluster->max_size = 0; |
| found = false; |
| } |
| goto again; |
| } |
| |
| cluster->window_start = start * block_group->sectorsize + |
| entry->offset; |
| rb_erase(&entry->offset_index, &ctl->free_space_offset); |
| ret = tree_insert_offset(&cluster->root, entry->offset, |
| &entry->offset_index, 1); |
| BUG_ON(ret); |
| |
| return 0; |
| } |
| |
| /* |
| * This searches the block group for just extents to fill the cluster with. |
| */ |
| static int setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster, |
| u64 offset, u64 bytes, u64 min_bytes) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct btrfs_free_space *first = NULL; |
| struct btrfs_free_space *entry = NULL; |
| struct btrfs_free_space *prev = NULL; |
| struct btrfs_free_space *last; |
| struct rb_node *node; |
| u64 window_start; |
| u64 window_free; |
| u64 max_extent; |
| u64 max_gap = 128 * 1024; |
| |
| entry = tree_search_offset(ctl, offset, 0, 1); |
| if (!entry) |
| return -ENOSPC; |
| |
| /* |
| * We don't want bitmaps, so just move along until we find a normal |
| * extent entry. |
| */ |
| while (entry->bitmap) { |
| node = rb_next(&entry->offset_index); |
| if (!node) |
| return -ENOSPC; |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| } |
| |
| window_start = entry->offset; |
| window_free = entry->bytes; |
| max_extent = entry->bytes; |
| first = entry; |
| last = entry; |
| prev = entry; |
| |
| while (window_free <= min_bytes) { |
| node = rb_next(&entry->offset_index); |
| if (!node) |
| return -ENOSPC; |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| |
| if (entry->bitmap) |
| continue; |
| /* |
| * we haven't filled the empty size and the window is |
| * very large. reset and try again |
| */ |
| if (entry->offset - (prev->offset + prev->bytes) > max_gap || |
| entry->offset - window_start > (min_bytes * 2)) { |
| first = entry; |
| window_start = entry->offset; |
| window_free = entry->bytes; |
| last = entry; |
| max_extent = entry->bytes; |
| } else { |
| last = entry; |
| window_free += entry->bytes; |
| if (entry->bytes > max_extent) |
| max_extent = entry->bytes; |
| } |
| prev = entry; |
| } |
| |
| cluster->window_start = first->offset; |
| |
| node = &first->offset_index; |
| |
| /* |
| * now we've found our entries, pull them out of the free space |
| * cache and put them into the cluster rbtree |
| */ |
| do { |
| int ret; |
| |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| node = rb_next(&entry->offset_index); |
| if (entry->bitmap) |
| continue; |
| |
| rb_erase(&entry->offset_index, &ctl->free_space_offset); |
| ret = tree_insert_offset(&cluster->root, entry->offset, |
| &entry->offset_index, 0); |
| BUG_ON(ret); |
| } while (node && entry != last); |
| |
| cluster->max_size = max_extent; |
| |
| return 0; |
| } |
| |
| /* |
| * This specifically looks for bitmaps that may work in the cluster, we assume |
| * that we have already failed to find extents that will work. |
| */ |
| static int setup_cluster_bitmap(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster, |
| u64 offset, u64 bytes, u64 min_bytes) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct btrfs_free_space *entry; |
| struct rb_node *node; |
| int ret = -ENOSPC; |
| |
| if (ctl->total_bitmaps == 0) |
| return -ENOSPC; |
| |
| entry = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), 0, 1); |
| if (!entry) |
| return -ENOSPC; |
| |
| node = &entry->offset_index; |
| do { |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| node = rb_next(&entry->offset_index); |
| if (!entry->bitmap) |
| continue; |
| if (entry->bytes < min_bytes) |
| continue; |
| ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset, |
| bytes, min_bytes); |
| } while (ret && node); |
| |
| return ret; |
| } |
| |
| /* |
| * here we try to find a cluster of blocks in a block group. The goal |
| * is to find at least bytes free and up to empty_size + bytes free. |
| * We might not find them all in one contiguous area. |
| * |
| * returns zero and sets up cluster if things worked out, otherwise |
| * it returns -enospc |
| */ |
| int btrfs_find_space_cluster(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster, |
| u64 offset, u64 bytes, u64 empty_size) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| u64 min_bytes; |
| int ret; |
| |
| /* for metadata, allow allocates with more holes */ |
| if (btrfs_test_opt(root, SSD_SPREAD)) { |
| min_bytes = bytes + empty_size; |
| } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) { |
| /* |
| * we want to do larger allocations when we are |
| * flushing out the delayed refs, it helps prevent |
| * making more work as we go along. |
| */ |
| if (trans->transaction->delayed_refs.flushing) |
| min_bytes = max(bytes, (bytes + empty_size) >> 1); |
| else |
| min_bytes = max(bytes, (bytes + empty_size) >> 4); |
| } else |
| min_bytes = max(bytes, (bytes + empty_size) >> 2); |
| |
| spin_lock(&ctl->tree_lock); |
| |
| /* |
| * If we know we don't have enough space to make a cluster don't even |
| * bother doing all the work to try and find one. |
| */ |
| if (ctl->free_space < min_bytes) { |
| spin_unlock(&ctl->tree_lock); |
| return -ENOSPC; |
| } |
| |
| spin_lock(&cluster->lock); |
| |
| /* someone already found a cluster, hooray */ |
| if (cluster->block_group) { |
| ret = 0; |
| goto out; |
| } |
| |
| ret = setup_cluster_no_bitmap(block_group, cluster, offset, bytes, |
| min_bytes); |
| if (ret) |
| ret = setup_cluster_bitmap(block_group, cluster, offset, |
| bytes, min_bytes); |
| |
| if (!ret) { |
| atomic_inc(&block_group->count); |
| list_add_tail(&cluster->block_group_list, |
| &block_group->cluster_list); |
| cluster->block_group = block_group; |
| } |
| out: |
| spin_unlock(&cluster->lock); |
| spin_unlock(&ctl->tree_lock); |
| |
| return ret; |
| } |
| |
| /* |
| * simple code to zero out a cluster |
| */ |
| void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster) |
| { |
| spin_lock_init(&cluster->lock); |
| spin_lock_init(&cluster->refill_lock); |
| cluster->root = RB_ROOT; |
| cluster->max_size = 0; |
| INIT_LIST_HEAD(&cluster->block_group_list); |
| cluster->block_group = NULL; |
| } |
| |
| int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group, |
| u64 *trimmed, u64 start, u64 end, u64 minlen) |
| { |
| struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| struct btrfs_free_space *entry = NULL; |
| struct btrfs_fs_info *fs_info = block_group->fs_info; |
| u64 bytes = 0; |
| u64 actually_trimmed; |
| int ret = 0; |
| |
| *trimmed = 0; |
| |
| while (start < end) { |
| spin_lock(&ctl->tree_lock); |
| |
| if (ctl->free_space < minlen) { |
| spin_unlock(&ctl->tree_lock); |
| break; |
| } |
| |
| entry = tree_search_offset(ctl, start, 0, 1); |
| if (!entry) |
| entry = tree_search_offset(ctl, |
| offset_to_bitmap(ctl, start), |
| 1, 1); |
| |
| if (!entry || entry->offset >= end) { |
| spin_unlock(&ctl->tree_lock); |
| break; |
| } |
| |
| if (entry->bitmap) { |
| ret = search_bitmap(ctl, entry, &start, &bytes); |
| if (!ret) { |
| if (start >= end) { |
| spin_unlock(&ctl->tree_lock); |
| break; |
| } |
| bytes = min(bytes, end - start); |
| bitmap_clear_bits(ctl, entry, start, bytes); |
| if (entry->bytes == 0) |
| free_bitmap(ctl, entry); |
| } else { |
| start = entry->offset + BITS_PER_BITMAP * |
| block_group->sectorsize; |
| spin_unlock(&ctl->tree_lock); |
| ret = 0; |
| continue; |
| } |
| } else { |
| start = entry->offset; |
| bytes = min(entry->bytes, end - start); |
| unlink_free_space(ctl, entry); |
| kmem_cache_free(btrfs_free_space_cachep, entry); |
| } |
| |
| spin_unlock(&ctl->tree_lock); |
| |
| if (bytes >= minlen) { |
| int update_ret; |
| update_ret = btrfs_update_reserved_bytes(block_group, |
| bytes, 1, 1); |
| |
| ret = btrfs_error_discard_extent(fs_info->extent_root, |
| start, |
| bytes, |
| &actually_trimmed); |
| |
| btrfs_add_free_space(block_group, start, bytes); |
| if (!update_ret) |
| btrfs_update_reserved_bytes(block_group, |
| bytes, 0, 1); |
| |
| if (ret) |
| break; |
| *trimmed += actually_trimmed; |
| } |
| start += bytes; |
| bytes = 0; |
| |
| if (fatal_signal_pending(current)) { |
| ret = -ERESTARTSYS; |
| break; |
| } |
| |
| cond_resched(); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Find the left-most item in the cache tree, and then return the |
| * smallest inode number in the item. |
| * |
| * Note: the returned inode number may not be the smallest one in |
| * the tree, if the left-most item is a bitmap. |
| */ |
| u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root) |
| { |
| struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl; |
| struct btrfs_free_space *entry = NULL; |
| u64 ino = 0; |
| |
| spin_lock(&ctl->tree_lock); |
| |
| if (RB_EMPTY_ROOT(&ctl->free_space_offset)) |
| goto out; |
| |
| entry = rb_entry(rb_first(&ctl->free_space_offset), |
| struct btrfs_free_space, offset_index); |
| |
| if (!entry->bitmap) { |
| ino = entry->offset; |
| |
| unlink_free_space(ctl, entry); |
| entry->offset++; |
| entry->bytes--; |
| if (!entry->bytes) |
| kmem_cache_free(btrfs_free_space_cachep, entry); |
| else |
| link_free_space(ctl, entry); |
| } else { |
| u64 offset = 0; |
| u64 count = 1; |
| int ret; |
| |
| ret = search_bitmap(ctl, entry, &offset, &count); |
| BUG_ON(ret); |
| |
| ino = offset; |
| bitmap_clear_bits(ctl, entry, offset, 1); |
| if (entry->bytes == 0) |
| free_bitmap(ctl, entry); |
| } |
| out: |
| spin_unlock(&ctl->tree_lock); |
| |
| return ino; |
| } |
| |
| struct inode *lookup_free_ino_inode(struct btrfs_root *root, |
| struct btrfs_path *path) |
| { |
| struct inode *inode = NULL; |
| |
| spin_lock(&root->cache_lock); |
| if (root->cache_inode) |
| inode = igrab(root->cache_inode); |
| spin_unlock(&root->cache_lock); |
| if (inode) |
| return inode; |
| |
| inode = __lookup_free_space_inode(root, path, 0); |
| if (IS_ERR(inode)) |
| return inode; |
| |
| spin_lock(&root->cache_lock); |
| if (!root->fs_info->closing) |
| root->cache_inode = igrab(inode); |
| spin_unlock(&root->cache_lock); |
| |
| return inode; |
| } |
| |
| int create_free_ino_inode(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_path *path) |
| { |
| return __create_free_space_inode(root, trans, path, |
| BTRFS_FREE_INO_OBJECTID, 0); |
| } |
| |
| int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root) |
| { |
| struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; |
| struct btrfs_path *path; |
| struct inode *inode; |
| int ret = 0; |
| u64 root_gen = btrfs_root_generation(&root->root_item); |
| |
| if (!btrfs_test_opt(root, INODE_MAP_CACHE)) |
| return 0; |
| |
| /* |
| * If we're unmounting then just return, since this does a search on the |
| * normal root and not the commit root and we could deadlock. |
| */ |
| smp_mb(); |
| if (fs_info->closing) |
| return 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return 0; |
| |
| inode = lookup_free_ino_inode(root, path); |
| if (IS_ERR(inode)) |
| goto out; |
| |
| if (root_gen != BTRFS_I(inode)->generation) |
| goto out_put; |
| |
| ret = __load_free_space_cache(root, inode, ctl, path, 0); |
| |
| if (ret < 0) |
| printk(KERN_ERR "btrfs: failed to load free ino cache for " |
| "root %llu\n", root->root_key.objectid); |
| out_put: |
| iput(inode); |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| int btrfs_write_out_ino_cache(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_path *path) |
| { |
| struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; |
| struct inode *inode; |
| int ret; |
| |
| if (!btrfs_test_opt(root, INODE_MAP_CACHE)) |
| return 0; |
| |
| inode = lookup_free_ino_inode(root, path); |
| if (IS_ERR(inode)) |
| return 0; |
| |
| ret = __btrfs_write_out_cache(root, inode, ctl, NULL, trans, path, 0); |
| if (ret < 0) |
| printk(KERN_ERR "btrfs: failed to write free ino cache " |
| "for root %llu\n", root->root_key.objectid); |
| |
| iput(inode); |
| return ret; |
| } |