summaryrefslogtreecommitdiffstats
path: root/drivers/md/raid5.c
diff options
context:
space:
mode:
authorhui jiao <simonjiaoh@gmail.com>2014-06-05 05:34:24 +0200
committerNeilBrown <neilb@suse.de>2014-06-05 09:18:19 +0200
commit2844dc32ea67044b345221067207ce67ffe8da76 (patch)
tree4f235e9eacd5a86110b70c39fa21673bb2916946 /drivers/md/raid5.c
parentraid5: add an option to avoid copy data from bio to stripe cache (diff)
downloadlinux-2844dc32ea67044b345221067207ce67ffe8da76.tar.xz
linux-2844dc32ea67044b345221067207ce67ffe8da76.zip
md/raid5: deadlock between retry_aligned_read with barrier io
A chunk aligned read increases counter active_aligned_reads and decreases it after sub-device handle it successfully. But when a read error occurs, the read redispatched by raid5d, and the active_aligned_reads will not be decreased until we can grab a stripe head in retry_aligned_read. Now suppose, a barrier io comes, set conf->quiesce to 2, and wait until both active_stripes and active_aligned_reads are zero. The retried chunk aligned read gets stuck at get_active_stripe waiting until conf->quiesce becomes 0. Retry_aligned_read and barrier io are waiting each other now. One possible solution is that we ignore conf->quiesce, let the retried aligned read finish. I reproduced this deadlock and test this patch on centos6.0 Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/raid5.c')
-rw-r--r--drivers/md/raid5.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index d69fd9888c2c..ce421e3a3980 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5115,7 +5115,7 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio)
/* already done this stripe */
continue;
- sh = get_active_stripe(conf, sector, 0, 1, 0);
+ sh = get_active_stripe(conf, sector, 0, 1, 1);
if (!sh) {
/* failed to get a stripe - must wait */