From 486f0644c3482cbf64fe804499836e1f05abec14 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 25 Feb 2015 12:10:35 +1100 Subject: md/raid5: move max_nr_stripes management into grow_one_stripe and drop_one_stripe Rather than adjusting max_nr_stripes whenever {grow,drop}_one_stripe() succeeds, do it inside the functions. Also choose the correct hash to handle next inside the functions. This removes duplication and will help with future new uses of {grow,drop}_one_stripe. This also fixes a minor bug where the "md/raid:%md: allocate XXkB" message always said "0kB". Signed-off-by: NeilBrown --- drivers/md/raid5.c | 57 +++++++++++++++++++++++------------------------------- 1 file changed, 24 insertions(+), 33 deletions(-) (limited to 'drivers') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index ed8e34153c3d..78ac7dc853c7 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -1963,7 +1963,7 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) put_cpu(); } -static int grow_one_stripe(struct r5conf *conf, int hash, gfp_t gfp) +static int grow_one_stripe(struct r5conf *conf, gfp_t gfp) { struct stripe_head *sh; sh = kmem_cache_zalloc(conf->slab_cache, gfp); @@ -1979,7 +1979,8 @@ static int grow_one_stripe(struct r5conf *conf, int hash, gfp_t gfp) kmem_cache_free(conf->slab_cache, sh); return 0; } - sh->hash_lock_index = hash; + sh->hash_lock_index = + conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS; /* we just created an active stripe so... */ atomic_set(&sh->count, 1); atomic_inc(&conf->active_stripes); @@ -1989,6 +1990,7 @@ static int grow_one_stripe(struct r5conf *conf, int hash, gfp_t gfp) INIT_LIST_HEAD(&sh->batch_list); sh->batch_head = NULL; release_stripe(sh); + conf->max_nr_stripes++; return 1; } @@ -1996,7 +1998,6 @@ static int grow_stripes(struct r5conf *conf, int num) { struct kmem_cache *sc; int devs = max(conf->raid_disks, conf->previous_raid_disks); - int hash; if (conf->mddev->gendisk) sprintf(conf->cache_name[0], @@ -2014,13 +2015,10 @@ static int grow_stripes(struct r5conf *conf, int num) return 1; conf->slab_cache = sc; conf->pool_size = devs; - hash = conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS; - while (num--) { - if (!grow_one_stripe(conf, hash, GFP_KERNEL)) + while (num--) + if (!grow_one_stripe(conf, GFP_KERNEL)) return 1; - conf->max_nr_stripes++; - hash = (hash + 1) % NR_STRIPE_HASH_LOCKS; - } + return 0; } @@ -2210,9 +2208,10 @@ static int resize_stripes(struct r5conf *conf, int newsize) return err; } -static int drop_one_stripe(struct r5conf *conf, int hash) +static int drop_one_stripe(struct r5conf *conf) { struct stripe_head *sh; + int hash = (conf->max_nr_stripes - 1) % NR_STRIPE_HASH_LOCKS; spin_lock_irq(conf->hash_locks + hash); sh = get_free_stripe(conf, hash); @@ -2223,15 +2222,15 @@ static int drop_one_stripe(struct r5conf *conf, int hash) shrink_buffers(sh); kmem_cache_free(conf->slab_cache, sh); atomic_dec(&conf->active_stripes); + conf->max_nr_stripes--; return 1; } static void shrink_stripes(struct r5conf *conf) { - int hash; - for (hash = 0; hash < NR_STRIPE_HASH_LOCKS; hash++) - while (drop_one_stripe(conf, hash)) - ; + while (conf->max_nr_stripes && + drop_one_stripe(conf)) + ; if (conf->slab_cache) kmem_cache_destroy(conf->slab_cache); @@ -5822,30 +5821,22 @@ raid5_set_cache_size(struct mddev *mddev, int size) { struct r5conf *conf = mddev->private; int err; - int hash; if (size <= 16 || size > 32768) return -EINVAL; - hash = (conf->max_nr_stripes - 1) % NR_STRIPE_HASH_LOCKS; - while (size < conf->max_nr_stripes) { - if (drop_one_stripe(conf, hash)) - conf->max_nr_stripes--; - else - break; - hash--; - if (hash < 0) - hash = NR_STRIPE_HASH_LOCKS - 1; - } + + while (size < conf->max_nr_stripes && + drop_one_stripe(conf)) + ; + err = md_allow_write(mddev); if (err) return err; - hash = conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS; - while (size > conf->max_nr_stripes) { - if (grow_one_stripe(conf, hash, GFP_KERNEL)) - conf->max_nr_stripes++; - else break; - hash = (hash + 1) % NR_STRIPE_HASH_LOCKS; - } + + while (size > conf->max_nr_stripes) + if (!grow_one_stripe(conf, GFP_KERNEL)) + break; + return 0; } EXPORT_SYMBOL(raid5_set_cache_size); @@ -6451,7 +6442,7 @@ static struct r5conf *setup_conf(struct mddev *mddev) conf->prev_algo = mddev->layout; } - memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + + memory = NR_STRIPES * (sizeof(struct stripe_head) + max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; atomic_set(&conf->empty_inactive_list_nr, NR_STRIPE_HASH_LOCKS); if (grow_stripes(conf, NR_STRIPES)) { -- cgit v1.2.3