found_type really holds the type of extent and is guaranteed to to have a value between [0, 2]. The only time it can contain anything different is if btrfs_lookup_file_extent returned a positive value and the previous item is different than an extent. Avoid this situation by simply checking found_key.type rather than assigning the item type to found_type intermittently. Also make the variable an u8 to reduce stack usage. No functional changes.
Signed-off-by: Nikolay Borisov <[email protected]> --- fs/btrfs/inode.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 73ae4428d0df..fe25f66a98d9 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6746,7 +6746,7 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode, u64 extent_start = 0; u64 extent_end = 0; u64 objectid = btrfs_ino(inode); - u32 found_type; + u8 extent_type; struct btrfs_path *path = NULL; struct btrfs_root *root = inode->root; struct btrfs_file_extent_item *item; @@ -6812,11 +6812,9 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode, leaf = path->nodes[0]; item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); - /* are we inside the extent that was found? */ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); - found_type = found_key.type; if (found_key.objectid != objectid || - found_type != BTRFS_EXTENT_DATA_KEY) { + found_key.type != BTRFS_EXTENT_DATA_KEY) { /* * If we backup past the first extent we want to move forward * and see if there is an extent in front of us, otherwise we'll @@ -6827,16 +6825,16 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode, goto next; } - found_type = btrfs_file_extent_type(leaf, item); + extent_type = btrfs_file_extent_type(leaf, item); extent_start = found_key.offset; - if (found_type == BTRFS_FILE_EXTENT_REG || - found_type == BTRFS_FILE_EXTENT_PREALLOC) { + if (extent_type == BTRFS_FILE_EXTENT_REG || + extent_type == BTRFS_FILE_EXTENT_PREALLOC) { extent_end = extent_start + btrfs_file_extent_num_bytes(leaf, item); trace_btrfs_get_extent_show_fi_regular(inode, leaf, item, extent_start); - } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { size_t size; size = btrfs_file_extent_ram_bytes(leaf, item); @@ -6877,10 +6875,10 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode, btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em); - if (found_type == BTRFS_FILE_EXTENT_REG || - found_type == BTRFS_FILE_EXTENT_PREALLOC) { + if (extent_type == BTRFS_FILE_EXTENT_REG || + extent_type == BTRFS_FILE_EXTENT_PREALLOC) { goto insert; - } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { unsigned long ptr; char *map; size_t size; -- 2.17.1
