Btrfs: remove some dead code
Subsystems (2)
PATCH 1/1 Btrfs: remove some dead code
btrfs_get_extent() never returns NULL pointers, so this code introduces a static checker warning.
The btrfs_get_extent() is a bit complex, but trust me that it doesn't return NULLs and also if it did we would trigger the BUG_ON(!em) before the last return statement.
Signed-off-by Dan Carpenter <[email protected]>
fs/btrfs/file.c +4 -12
@@ -2397,13 +2397,8 @@ static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)int ret =0 ; em =btrfs_get_extent (BTRFS_I (inode),NULL ,0 , *start, *len,0 ); -if (IS_ERR_OR_NULL (em)) { -if (!em) - ret = -ENOMEM ; -else - ret =PTR_ERR (em); -return ret; - } +if (IS_ERR (em)) +return PTR_ERR (em);/* Hole or vacuum extent(only exists in no-hole mode) */ if (em->block_start =EXTENT_MAP_HOLE ) {
@@ -2893,11 +2888,8 @@ static long btrfs_fallocate(struct file *file, int mode,while (1 ) { em =btrfs_get_extent (BTRFS_I (inode),NULL ,0 , cur_offset, alloc_end - cur_offset,0 ); -if (IS_ERR_OR_NULL (em)) { -if (!em) - ret = -ENOMEM ; -else - ret =PTR_ERR (em); +if (IS_ERR (em)) { + ret =PTR_ERR (em);break ; } last_byte =min (extent_map_end (em), alloc_end);
fs/btrfs/inode.c +11 -14
@@ -6866,7 +6866,6 @@ static noinline int uncompress_inline(struct btrfs_path *path,* * This also copies inline extents directly into the page. */ - struct extent_map *btrfs_get_extent(struct btrfs_inode *inode, struct page *page, size_t pg_offset, u64 start, u64 len,
@@ -7175,19 +7174,17 @@ struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode, em =btrfs_get_extent (inode, page, pg_offset, start, len, create);if (IS_ERR (em))return em; -if (em) { -/* -* if our em maps to -* - a hole or -* - a pre-alloc extent, -* there might actually be delalloc bytes behind it. -*/ -if (em->block_start !=EXTENT_MAP_HOLE && - !test_bit (EXTENT_FLAG_PREALLOC , &em->flags)) -return em; -else - hole_em = em; - } +/* +* if our em maps to +* - a hole or +* - a pre-alloc extent, +* there might actually be delalloc bytes behind it. +*/ +if (em->block_start !=EXTENT_MAP_HOLE && + !test_bit (EXTENT_FLAG_PREALLOC , &em->flags)) +return em; +else + hole_em = em;/* check to see if we've wrapped (len = -1 or similar) */ end = start + len;
Quoted 8 lines · Dan Carpenter
btrfs_get_extent()never returns NULL pointers, so this code introduces a static checker warning.The
btrfs_get_extent()is a bit complex, but trust me that it doesn't return NULLs and also if it did we would trigger theBUG_ON(!em)before the last return statement.Signed-off-by Dan Carpenter <[email protected]>
Added to 4.12, thanks. I've updated the subject line so it reflects what the patch does.