Commit 462b0b2a authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: return proper mapped length for RAID56 profiles in __btrfs_map_block() 



For profiles other than RAID56, __btrfs_map_block() returns @map_length
as min(stripe_end, logical + *length), which is also the same result
from btrfs_get_io_geometry().

But for RAID56, __btrfs_map_block() returns @map_length as stripe_len.

This strange behavior is going to hurt incoming bio split at
btrfs_map_bio() time, as we will use @map_length as bio split size.

Fix this behavior by returning @map_length by the same calculation as
for other profiles.

Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Tested-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent ff18a4af

fs/btrfs/volumes.c

+4 −1
Original line number Diff line number Diff line
@@ -6471,7 +6471,10 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, 
			num_stripes = map->num_stripes;

			max_errors = btrfs_chunk_max_errors(map);



			*length = map->stripe_len;

			/* Return the length to the full stripe end */

			*length = min(logical + *length,

				      raid56_full_stripe_start + em->start +

				      data_stripes * stripe_len) - logical;

			stripe_index = 0;

			stripe_offset = 0;

		} else {