[PATCH 4.9 11/39] Revert "Btrfs: fix scrub to repair raid6 corruption"

Greg Kroah-Hartman
2018-06-24T15:49:22Z

From: Sasha Levin <Alexander.Levin@microsoft.com>

This reverts commit 186a6519dc94964a4c5c68fca482f20f71551f26.

This commit used an incorrect log message.

Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/btrfs/raid56.c | 18 ++++--------------
fs/btrfs/volumes.c | 9 +--------
2 files changed, 5 insertions(+), 22 deletions(-)

--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -2161,21 +2161,11 @@ int raid56_parity_recover(struct btrfs_r
}

/*
- * Loop retry:
- * for 'mirror == 2', reconstruct from all other stripes.
- * for 'mirror_num > 2', select a stripe to fail on every retry.
+ * reconstruct from the q stripe if they are
+ * asking for mirror 3
*/
- if (mirror_num > 2) {
- /*
- * 'mirror == 3' is to fail the p stripe and
- * reconstruct from the q stripe. 'mirror > 3' is to
- * fail a data stripe and reconstruct from p+q stripe.
- */
- rbio->failb = rbio->real_stripes - (mirror_num - 1);
- ASSERT(rbio->failb > 0);
- if (rbio->failb <= rbio->faila)
- rbio->failb--;
- }
+ if (mirror_num == 3)
+ rbio->failb = rbio->real_stripes - 2;

ret = lock_stripe_add(rbio);

--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5186,14 +5186,7 @@ int btrfs_num_copies(struct btrfs_fs_inf
else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
ret = 2;
else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
- /*
- * There could be two corrupted data stripes, we need
- * to loop retry in order to rebuild the correct data.
- *
- * Fail a stripe at a time on every retry except the
- * stripe under reconstruction.
- */
- ret = map->num_stripes;
+ ret = 3;
else
ret = 1;
free_extent_map(em);