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author | NeilBrown <neilb@suse.de> | 2015-02-18 11:35:14 +1100 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-06 14:43:31 -0800 |
commit | 0ed85c574669de46947dbee50f7e0c33981bd148 (patch) | |
tree | 32593f470c16bd5d3a51b5eeb8d5fdfb953932ee /drivers/md | |
parent | 6318c31d3018c981aed0c4f8b38387663a107971 (diff) | |
download | lwn-0ed85c574669de46947dbee50f7e0c33981bd148.tar.gz lwn-0ed85c574669de46947dbee50f7e0c33981bd148.zip |
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>
Diffstat (limited to 'drivers/md')
-rw-r--r-- | drivers/md/raid5.c | 3 |
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 */ |