| From | Kamal Mostafa <> | Subject | [PATCH 3.13 135/163] md/raid1: count resync requests in nr_pending. | Date | Thu, 9 Oct 2014 14:02:40 -0700 |
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3.13.11.9 -stable review patch. If anyone has any objections, please let me know.
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From: NeilBrown <neilb@suse.de>
commit 34e97f170149bfa14979581c4c748bc9b4b79d5b upstream.
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 Reported-by: Brassow Jonathan <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/md/raid1.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 5ad11da..2cf4f69 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -858,6 +858,7 @@ 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); } @@ -867,6 +868,7 @@ 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); } -- 1.9.1
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