md/raid1: update next_resync under resync_lock. (c2fd4c94) · Commits · 戴 / test

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: cc: stable@vger.kernel.org (v3.13+) Signed-off-by:

NeilBrown <neilb@suse.de>

drivers/md/raid1.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -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();
		/*

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