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 <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ed8e341..78ac7dc 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1963,7 +1963,7 @@
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 @@
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 @@
INIT_LIST_HEAD(&sh->batch_list);
sh->batch_head = NULL;
release_stripe(sh);
+ conf->max_nr_stripes++;
return 1;
}
@@ -1996,7 +1998,6 @@
{
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 @@
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 @@
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 @@
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 @@
{
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 @@
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)) {