diff mbox series

[2/5] btrfs: return proper mapped length for RAID56 profiles in __btrfs_map_block()

Message ID 20220615151515.888424-3-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [1/5] btrfs: remove a bunch of pointles stripe_len arguments | expand

Commit Message

Christoph Hellwig June 15, 2022, 3:15 p.m. UTC 
From: Qu Wenruo <wqu@suse.com>

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 return @map_length by the same calculatioin as
other profiles

Signed-off-by: Qu Wenruo <wqu@suse.com>
[hch: rebased]
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/btrfs/volumes.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Johannes Thumshirn June 17, 2022, 9:54 a.m. UTC | #1 
Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
diff mbox series

Patch

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 07b1e005d89df..ff777e39d5f4a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6469,7 +6469,10 @@  static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 			num_stripes = map->num_stripes;
 			max_errors = nr_parity_stripes(map);
 
-			*length = map->stripe_len;
+			/* Return the length to the full stripe end */
+			*length = min(raid56_full_stripe_start + em->start +
+				      data_stripes * stripe_len,
+				      logical + *length) - logical;
 			stripe_index = 0;
 			stripe_offset = 0;
 		} else {