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| author | Marcos Paulo de Souza <mpdesouza@suse.com> | 2021-07-29 10:22:16 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2021-08-23 13:19:09 +0200 |
| commit | 0ff40a910f5649dfacc4fb5daa7e73692196342d (patch) | |
| tree | d72db74b8b671afb17c773282fa22dc1b0dd0e06 /fs/btrfs/super.c | |
| parent | btrfs: print if fsverity support is built in when loading module (diff) | |
| download | linux-0ff40a910f5649dfacc4fb5daa7e73692196342d.tar.xz linux-0ff40a910f5649dfacc4fb5daa7e73692196342d.zip | |
btrfs: introduce btrfs_search_backwards function
It's a common practice to start a search using offset (u64)-1, which is
the u64 maximum value, meaning that we want the search_slot function to
be set in the last item with the same objectid and type.
Once we are in this position, it's a matter to start a search backwards
by calling btrfs_previous_item, which will check if we'll need to go to
a previous leaf and other necessary checks, only to be sure that we are
in last offset of the same object and type.
The new btrfs_search_backwards function does the all these steps when
necessary, and can be used to avoid code duplication.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/super.c')
| -rw-r--r-- | fs/btrfs/super.c | 26 |
1 files changed, 6 insertions, 20 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index d444338db3c6..409bee3e7587 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1201,21 +1201,14 @@ char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, key.type = BTRFS_ROOT_BACKREF_KEY; key.offset = (u64)-1; - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + ret = btrfs_search_backwards(root, &key, path); if (ret < 0) { goto err; } else if (ret > 0) { - ret = btrfs_previous_item(root, path, subvol_objectid, - BTRFS_ROOT_BACKREF_KEY); - if (ret < 0) { - goto err; - } else if (ret > 0) { - ret = -ENOENT; - goto err; - } + ret = -ENOENT; + goto err; } - btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); subvol_objectid = key.offset; root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], @@ -1248,21 +1241,14 @@ char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, key.type = BTRFS_INODE_REF_KEY; key.offset = (u64)-1; - ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); + ret = btrfs_search_backwards(fs_root, &key, path); if (ret < 0) { goto err; } else if (ret > 0) { - ret = btrfs_previous_item(fs_root, path, dirid, - BTRFS_INODE_REF_KEY); - if (ret < 0) { - goto err; - } else if (ret > 0) { - ret = -ENOENT; - goto err; - } + ret = -ENOENT; + goto err; } - btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); dirid = key.offset; inode_ref = btrfs_item_ptr(path->nodes[0], |