| Message ID | 1425303476-1952-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 68a03d7f25ee..b1b9efb5359f 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3111,7 +3111,8 @@ 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 */
This is a note to let you know that I have just added a patch titled md/raid5: Fix livelock when array is both resyncing and degraded. to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt8. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From b5fdd9498e642d232785656059068ea52bfde9ca Mon Sep 17 00:00:00 2001 From: NeilBrown <neilb@suse.de> Date: Wed, 18 Feb 2015 11:35:14 +1100 Subject: 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: Luis Henriques <luis.henriques@canonical.com> --- drivers/md/raid5.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)