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Commit 486f0644 authored by NeilBrown's avatar NeilBrown
Browse files

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: default avatarNeilBrown <neilb@suse.de>
parent a9683a79

drivers/md/raid5.c

+24 −33
Original line number Diff line number Diff line
@@ -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);
@@ -2223,14 +2222,14 @@ 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)
@@ -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)) {