There isn't locking setting STRIPE_DELAYED and STRIPE_PREREAD_ACTIVE bits, but the two bits have relationship. A delayed stripe can be moved to hold list only when preread active stripe count is below IO_THRESHOLD. If a stripe has both the bits set, such stripe will be in delayed list and preread count not 0, which will make such stripe never leave delayed list. Signed-off-by: Shaohua Li <shli@xxxxxxxxxxxx> --- drivers/md/raid5.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) Index: linux/drivers/md/raid5.c =================================================================== --- linux.orig/drivers/md/raid5.c 2012-06-25 14:36:15.964613183 +0800 +++ linux/drivers/md/raid5.c 2012-06-25 14:36:57.280096788 +0800 @@ -196,12 +196,14 @@ static void __release_stripe(struct r5co BUG_ON(!list_empty(&sh->lru)); BUG_ON(atomic_read(&conf->active_stripes)==0); if (test_bit(STRIPE_HANDLE, &sh->state)) { - if (test_bit(STRIPE_DELAYED, &sh->state)) + if (test_bit(STRIPE_DELAYED, &sh->state) && + !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) list_add_tail(&sh->lru, &conf->delayed_list); else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && sh->bm_seq - conf->seq_write > 0) list_add_tail(&sh->lru, &conf->bitmap_list); else { + clear_bit(STRIPE_DELAYED, &sh->state); clear_bit(STRIPE_BIT_DELAY, &sh->state); list_add_tail(&sh->lru, &conf->handle_list); } -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html