From: NeilBrown <neilb@suse.de>
Date: Thu, 21 May 2015 05:10:01 +0000 (+1000)
Subject: md/raid5: ensure whole batch is delayed for all required bitmap updates.
X-Git-Tag: v4.9.8~4201^2~9
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2b6b24574256c05be145936f1493aec74c6904e5;p=platform%2Fkernel%2Flinux-rpi3.git

md/raid5: ensure whole batch is delayed for all required bitmap updates.

When we add a stripe to a batch, we need to be sure that
head stripe will wait for the bitmap update required for the new
stripe.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index b9f2b9c..c55a68f 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -837,6 +837,15 @@ static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh
 		    < IO_THRESHOLD)
 			md_wakeup_thread(conf->mddev->thread);
 
+	if (test_and_clear_bit(STRIPE_BIT_DELAY, &sh->state)) {
+		int seq = sh->bm_seq;
+		if (test_bit(STRIPE_BIT_DELAY, &sh->batch_head->state) &&
+		    sh->batch_head->bm_seq > seq)
+			seq = sh->batch_head->bm_seq;
+		set_bit(STRIPE_BIT_DELAY, &sh->batch_head->state);
+		sh->batch_head->bm_seq = seq;
+	}
+
 	atomic_inc(&sh->count);
 unlock_out:
 	unlock_two_stripes(head, sh);