From: NeilBrown Date: Tue, 16 Sep 2014 02:14:14 +0000 (+1000) Subject: md/raid1: count resync requests in nr_pending. X-Git-Tag: v3.17-rc7~21^2~1 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=34e97f170149bfa14979581c4c748bc9b4b79d5b;p=linux.git md/raid1: count resync requests in nr_pending. Both normal IO and resync IO can be retried with reschedule_retry() and so be counted into ->nr_queued, but only normal IO gets counted in ->nr_pending. Before the recent improvement to RAID1 resync there could only possibly have been one or the other on the queue. When handling a read failure it could only be normal IO. So when handle_read_error() called freeze_array() the fact that freeze_array only compares ->nr_queued against ->nr_pending was safe. But now that these two types can interleave, we can have both normal and resync IO requests queued, so we need to count them both in nr_pending. This error can lead to freeze_array() hanging if there is a read error, so it is suitable for -stable. Fixes: 79ef3a8aa1cb1523cc231c9a90a278333c21f761 cc: stable@vger.kernel.org (v3.13+) Reported-by: Brassow Jonathan Signed-off-by: NeilBrown --- diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index acfccec9ea3a..35649ddac9bc 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -856,6 +856,7 @@ static void raise_barrier(struct r1conf *conf, sector_t sector_nr) conf->next_resync + RESYNC_SECTORS), conf->resync_lock); + conf->nr_pending++; spin_unlock_irq(&conf->resync_lock); } @@ -865,6 +866,7 @@ static void lower_barrier(struct r1conf *conf) BUG_ON(conf->barrier <= 0); spin_lock_irqsave(&conf->resync_lock, flags); conf->barrier--; + conf->nr_pending--; spin_unlock_irqrestore(&conf->resync_lock, flags); wake_up(&conf->wait_barrier); }