diff options
authorNeilBrown <neilb@suse.de>2015-02-18 11:35:14 +1100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-06 14:43:31 -0800
commit0ed85c574669de46947dbee50f7e0c33981bd148 (patch)
parent6318c31d3018c981aed0c4f8b38387663a107971 (diff)
md/raid5: Fix livelock when array is both resyncing and degraded.
commit 26ac107378c4742978216be1005b7291b799c7b2 upstream. Commit a7854487cd7128a30a7f4f5259de9f67d5efb95f: md: When RAID5 is dirty, force reconstruct-write instead of read-modify-write. Causes an RCW cycle to be forced even when the array is degraded. A degraded array cannot support RCW as that requires reading all data blocks, and one may be missing. Forcing an RCW when it is not possible causes a live-lock and the code spins, repeatedly deciding to do something that cannot succeed. So change the condition to only force RCW on non-degraded arrays. Reported-by: Manibalan P <pmanibalan@amiindia.co.in> Bisected-by: Jes Sorensen <Jes.Sorensen@redhat.com> Tested-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de> Fixes: a7854487cd7128a30a7f4f5259de9f67d5efb95f Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 175584ad643f..3545fafe2027 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3071,7 +3071,8 @@ static void handle_stripe_dirtying(struct r5conf *conf,
* generate correct data from the parity.
if (conf->max_degraded == 2 ||
- (recovery_cp < MaxSector && sh->sector >= recovery_cp)) {
+ (recovery_cp < MaxSector && sh->sector >= recovery_cp &&
+ s->failed == 0)) {
/* Calculate the real rcw later - for now make it
* look like rcw is cheaper