Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9986277e authored by Dan Carpenter's avatar Dan Carpenter Committed by David Sterba
Browse files

Btrfs: handle only applicable errors returned by btrfs_get_extent 



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: default avatarDan Carpenter <dan.carpenter@oracle.com>
[ updated subject ]
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 82bafb38

fs/btrfs/file.c

+4 −12
Original line number Diff line number Diff line
@@ -2342,13 +2342,8 @@ 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) {
@@ -2835,10 +2830,7 @@ 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

		if (IS_ERR(em)) {

			ret = PTR_ERR(em);

			break;

		}

fs/btrfs/inode.c

+11 −14
Original line number Diff line number Diff line
@@ -6736,7 +6736,6 @@ 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,
@@ -7045,9 +7044,8 @@ 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

	 * If our em maps to:

	 * - a hole or

	 * - a pre-alloc extent,

	 * there might actually be delalloc bytes behind it.
@@ -7057,7 +7055,6 @@ struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode, 
		return em;

	else

		hole_em = em;

	}



	/* check to see if we've wrapped (len == -1 or similar) */

	end = start + len;