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

Commit c53839fc authored by Johannes Thumshirn's avatar Johannes Thumshirn Committed by David Sterba
Browse files

btrfs: warn if extent buffer mapping crosses a page boundary in csum_tree_block 



Since commit d2e174d5 ("btrfs: document extent mapping assumptions in
checksum") we have a comment in place why map_private_extent_buffer()
can't return 1 in the csum_tree_block() case.

Make this a bit more explicit and WARN_ON() in case this this assumption
breaks.

Signed-off-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 2996e1f8

fs/btrfs/disk-io.c

+1 −1
Original line number Diff line number Diff line
@@ -285,7 +285,7 @@ static int csum_tree_block(struct extent_buffer *buf, u8 *result) 
		 */

		err = map_private_extent_buffer(buf, offset, 32,

					&kaddr, &map_start, &map_len);

		if (err)

		if (WARN_ON(err))

			return err;

		cur_len = min(len, map_len - (offset - map_start));

		crc = btrfs_csum_data(kaddr + offset - map_start,