From c2fd4c94deedb89ac1746c4a53219be499372c06 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 10 Sep 2014 16:01:24 +1000 Subject: [PATCH] md/raid1: update next_resync under resync_lock. raise_barrier() uses next_resync as part of its calculations, so it really should be updated first, instead of afterwards. next_resync is always used under resync_lock so update it under resync lock to, just before it is used. That is safest. This could cause normal IO and resync IO to interact badly so it suitable for -stable. Fixes: 79ef3a8aa1cb1523cc231c9a90a278333c21f761 cc: stable@vger.kernel.org (v3.13+) Signed-off-by: NeilBrown --- drivers/md/raid1.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 3b14a495c424..acfccec9ea3a 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -827,7 +827,7 @@ static void flush_pending_writes(struct r1conf *conf) * there is no normal IO happeing. It must arrange to call * lower_barrier when the particular background IO completes. */ -static void raise_barrier(struct r1conf *conf) +static void raise_barrier(struct r1conf *conf, sector_t sector_nr) { spin_lock_irq(&conf->resync_lock); @@ -837,6 +837,7 @@ static void raise_barrier(struct r1conf *conf) /* block any new IO from starting */ conf->barrier++; + conf->next_resync = sector_nr; /* For these conditions we must wait: * A: while the array is in frozen state @@ -2543,9 +2544,8 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipp bitmap_cond_end_sync(mddev->bitmap, sector_nr); r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO); - raise_barrier(conf); - conf->next_resync = sector_nr; + raise_barrier(conf, sector_nr); rcu_read_lock(); /* -- 2.39.5