From b15a9dbdbfe72848b7ed4cd3f97fe80daaf99c89 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 22 May 2015 15:20:04 +1000 Subject: [PATCH] md/raid5: Ensure a batch member is not handled prematurely. If a stripe is a member of a batch, but not the head, it must not be handled separately from the rest of the batch. 'clear_batch_ready()' handles this requirement to some extent but not completely. If a member is passed to handle_stripe() a second time it returns '0' indicating the stripe can be handled, which is wrong. So add an extra test. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 42d0ea6..e587367 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4200,9 +4200,13 @@ static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s) static int clear_batch_ready(struct stripe_head *sh) { + /* Return '1' if this is a member of batch, or + * '0' if it is a lone stripe or a head which can now be + * handled. + */ struct stripe_head *tmp; if (!test_and_clear_bit(STRIPE_BATCH_READY, &sh->state)) - return 0; + return (sh->batch_head && sh->batch_head != sh); spin_lock(&sh->stripe_lock); if (!sh->batch_head) { spin_unlock(&sh->stripe_lock); -- 2.7.4