diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 78ea44336e75e06d5769b4a6158f2a1e506214e0..287cc3b30043a61e45af3635a437893dff9e3ccb 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -239,12 +239,47 @@ static void __release_stripe(struct r5conf *conf, struct stripe_head *sh) do_release_stripe(conf, sh); } +/* should hold conf->device_lock already */ +static int release_stripe_list(struct r5conf *conf) +{ + struct stripe_head *sh; + int count = 0; + struct llist_node *head; + + head = llist_del_all(&conf->released_stripes); + while (head) { + sh = llist_entry(head, struct stripe_head, release_list); + head = llist_next(head); + /* sh could be readded after STRIPE_ON_RELEASE_LIST is cleard */ + smp_mb(); + clear_bit(STRIPE_ON_RELEASE_LIST, &sh->state); + /* + * Don't worry the bit is set here, because if the bit is set + * again, the count is always > 1. This is true for + * STRIPE_ON_UNPLUG_LIST bit too. + */ + __release_stripe(conf, sh); + count++; + } + + return count; +} + static void release_stripe(struct stripe_head *sh) { struct r5conf *conf = sh->raid_conf; unsigned long flags; + bool wakeup; + if (test_and_set_bit(STRIPE_ON_RELEASE_LIST, &sh->state)) + goto slow_path; + wakeup = llist_add(&sh->release_list, &conf->released_stripes); + if (wakeup) + md_wakeup_thread(conf->mddev->thread); + return; +slow_path: local_irq_save(flags); + /* we are ok here if STRIPE_ON_RELEASE_LIST is set or not */ if (atomic_dec_and_lock(&sh->count, &conf->device_lock)) { do_release_stripe(conf, sh); spin_unlock(&conf->device_lock); @@ -491,7 +526,8 @@ get_active_stripe(struct r5conf *conf, sector_t sector, if (atomic_read(&sh->count)) { BUG_ON(!list_empty(&sh->lru) && !test_bit(STRIPE_EXPANDING, &sh->state) - && !test_bit(STRIPE_ON_UNPLUG_LIST, &sh->state)); + && !test_bit(STRIPE_ON_UNPLUG_LIST, &sh->state) + && !test_bit(STRIPE_ON_RELEASE_LIST, &sh->state)); } else { if (!test_bit(STRIPE_HANDLE, &sh->state)) atomic_inc(&conf->active_stripes); @@ -4127,6 +4163,10 @@ static void raid5_unplug(struct blk_plug_cb *blk_cb, bool from_schedule) */ smp_mb__before_clear_bit(); clear_bit(STRIPE_ON_UNPLUG_LIST, &sh->state); + /* + * STRIPE_ON_RELEASE_LIST could be set here. In that + * case, the count is always > 1 here + */ __release_stripe(conf, sh); cnt++; } @@ -4836,7 +4876,9 @@ static void raid5d(struct md_thread *thread) spin_lock_irq(&conf->device_lock); while (1) { struct bio *bio; - int batch_size; + int batch_size, released; + + released = release_stripe_list(conf); if ( !list_empty(&conf->bitmap_list)) { @@ -4861,7 +4903,7 @@ static void raid5d(struct md_thread *thread) } batch_size = handle_active_stripes(conf); - if (!batch_size) + if (!batch_size && !released) break; handled += batch_size; @@ -5176,6 +5218,7 @@ static struct r5conf *setup_conf(struct mddev *mddev) INIT_LIST_HEAD(&conf->delayed_list); INIT_LIST_HEAD(&conf->bitmap_list); INIT_LIST_HEAD(&conf->inactive_list); + init_llist_head(&conf->released_stripes); atomic_set(&conf->active_stripes, 0); atomic_set(&conf->preread_active_stripes, 0); atomic_set(&conf->active_aligned_reads, 0); diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index 70c49329ca9a23fbbad73061477ac0a0cfe80e6e..a98f99d2a58f52a8eabc62872cb04ef3fede9c51 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -197,6 +197,7 @@ enum reconstruct_states { struct stripe_head { struct hlist_node hash; struct list_head lru; /* inactive_list or handle_list */ + struct llist_node release_list; struct r5conf *raid_conf; short generation; /* increments with every * reshape */ @@ -321,6 +322,7 @@ enum { STRIPE_OPS_REQ_PENDING, STRIPE_ON_UNPLUG_LIST, STRIPE_DISCARD, + STRIPE_ON_RELEASE_LIST, }; /* @@ -445,6 +447,7 @@ struct r5conf { */ atomic_t active_stripes; struct list_head inactive_list; + struct llist_head released_stripes; wait_queue_head_t wait_for_stripe; wait_queue_head_t wait_for_overlap; int inactive_blocked; /* release of inactive stripes blocked,