diff options
Diffstat (limited to 'fs/btrfs/free-space-cache.c')
| -rw-r--r-- | fs/btrfs/free-space-cache.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index f488fac04d99..05efcc7061a7 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -23,10 +23,165 @@ #include "ctree.h" #include "free-space-cache.h" #include "transaction.h" +#include "disk-io.h" #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8) #define MAX_CACHE_BYTES_PER_GIG (32 * 1024) +struct inode *lookup_free_space_inode(struct btrfs_root *root, + struct btrfs_block_group_cache + *block_group, struct btrfs_path *path) +{ + 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; + + spin_lock(&block_group->lock); + if (block_group->inode) + inode = igrab(block_group->inode); + spin_unlock(&block_group->lock); + if (inode) + return inode; + + key.objectid = BTRFS_FREE_SPACE_OBJECTID; + key.offset = block_group->key.objectid; + 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(root, 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(root, 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); + } + + 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_block_group_cache *block_group, + struct btrfs_path *path) +{ + 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; + u64 objectid; + int ret; + + ret = btrfs_find_free_objectid(trans, root, 0, &objectid); + if (ret < 0) + return ret; + + ret = btrfs_insert_empty_inode(trans, root, path, objectid); + 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, + block_group->key.objectid); + btrfs_mark_buffer_dirty(leaf); + btrfs_release_path(root, path); + + key.objectid = BTRFS_FREE_SPACE_OBJECTID; + key.offset = block_group->key.objectid; + key.type = 0; + + ret = btrfs_insert_empty_item(trans, root, path, &key, + sizeof(struct btrfs_free_space_header)); + if (ret < 0) { + btrfs_release_path(root, 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(root, path); + + return 0; +} + +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; + } + + return btrfs_update_inode(trans, root, inode); +} + static inline unsigned long offset_to_bit(u64 bitmap_start, u64 sectorsize, u64 offset) { |