[PATCH 2/8] md/raid5: Ensure a batch member is not handled prematurely.
From: NeilBrown <hidden>
Date: 2015-05-22 05:30:58
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
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 <redacted> --- 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 c3ccefbd4fe7..9a803b735848 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c@@ -4192,9 +4192,13 @@ 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);