Commit 35849c75 authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
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[PATCH] md: Add sysfs access to raid6 stripe cache size 



.. just as we already have for raid5.

Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 978f946b

drivers/md/raid6main.c

+115 −34
Original line number Diff line number Diff line
@@ -115,7 +115,7 @@ static void __release_stripe(raid6_conf_t *conf, struct stripe_head *sh) 
			list_add_tail(&sh->lru, &conf->inactive_list);

			atomic_dec(&conf->active_stripes);

			if (!conf->inactive_blocked ||

			    atomic_read(&conf->active_stripes) < (NR_STRIPES*3/4))

			    atomic_read(&conf->active_stripes) < (conf->max_nr_stripes*3/4))

				wake_up(&conf->wait_for_stripe);

		}

	}
@@ -273,7 +273,8 @@ static struct stripe_head *get_active_stripe(raid6_conf_t *conf, sector_t sector 
				conf->inactive_blocked = 1;

				wait_event_lock_irq(conf->wait_for_stripe,

						    !list_empty(&conf->inactive_list) &&

						    (atomic_read(&conf->active_stripes) < (NR_STRIPES *3/4)

						    (atomic_read(&conf->active_stripes)

						     < (conf->max_nr_stripes *3/4)

						     || !conf->inactive_blocked),

						    conf->device_lock,

						    unplug_slaves(conf->mddev);
@@ -302,58 +303,69 @@ static struct stripe_head *get_active_stripe(raid6_conf_t *conf, sector_t sector 
	return sh;

}



static int grow_stripes(raid6_conf_t *conf, int num)

static int grow_one_stripe(raid6_conf_t *conf)

{

	struct stripe_head *sh;

	kmem_cache_t *sc;

	int devs = conf->raid_disks;



	sprintf(conf->cache_name, "raid6/%s", mdname(conf->mddev));



	sc = kmem_cache_create(conf->cache_name,

			       sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),

			       0, 0, NULL, NULL);

	if (!sc)

		return 1;

	conf->slab_cache = sc;

	while (num--) {

		sh = kmem_cache_alloc(sc, GFP_KERNEL);

	sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);

	if (!sh)

			return 1;

		memset(sh, 0, sizeof(*sh) + (devs-1)*sizeof(struct r5dev));

		return 0;

	memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev));

	sh->raid_conf = conf;

	spin_lock_init(&sh->lock);



	if (grow_buffers(sh, conf->raid_disks)) {

		shrink_buffers(sh, conf->raid_disks);

			kmem_cache_free(sc, sh);

			return 1;

		kmem_cache_free(conf->slab_cache, sh);

		return 0;

	}

	/* we just created an active stripe so... */

	atomic_set(&sh->count, 1);

	atomic_inc(&conf->active_stripes);

	INIT_LIST_HEAD(&sh->lru);

	release_stripe(sh);

	return 1;

}



static int grow_stripes(raid6_conf_t *conf, int num)

{

	kmem_cache_t *sc;

	int devs = conf->raid_disks;



	sprintf(conf->cache_name, "raid6/%s", mdname(conf->mddev));



	sc = kmem_cache_create(conf->cache_name,

			       sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),

			       0, 0, NULL, NULL);

	if (!sc)

		return 1;

	conf->slab_cache = sc;

	while (num--)

		if (!grow_one_stripe(conf))

			return 1;

	return 0;

}



static void shrink_stripes(raid6_conf_t *conf)

static int drop_one_stripe(raid6_conf_t *conf)

{

	struct stripe_head *sh;



	while (1) {

	spin_lock_irq(&conf->device_lock);

	sh = get_free_stripe(conf);

	spin_unlock_irq(&conf->device_lock);

	if (!sh)

			break;

		return 0;

	if (atomic_read(&sh->count))

		BUG();

	shrink_buffers(sh, conf->raid_disks);

	kmem_cache_free(conf->slab_cache, sh);

	atomic_dec(&conf->active_stripes);

	return 1;

}



static void shrink_stripes(raid6_conf_t *conf)

{

	while (drop_one_stripe(conf))

		;



	kmem_cache_destroy(conf->slab_cache);

	conf->slab_cache = NULL;

}
@@ -1912,6 +1924,74 @@ static void raid6d (mddev_t *mddev) 
	PRINTK("--- raid6d inactive\n");

}



static ssize_t

raid6_show_stripe_cache_size(mddev_t *mddev, char *page)

{

	raid6_conf_t *conf = mddev_to_conf(mddev);

	if (conf)

		return sprintf(page, "%d\n", conf->max_nr_stripes);

	else

		return 0;

}



static ssize_t

raid6_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)

{

	raid6_conf_t *conf = mddev_to_conf(mddev);

	char *end;

	int new;

	if (len >= PAGE_SIZE)

		return -EINVAL;

	if (!conf)

		return -ENODEV;



	new = simple_strtoul(page, &end, 10);

	if (!*page || (*end && *end != '\n') )

		return -EINVAL;

	if (new <= 16 || new > 32768)

		return -EINVAL;

	while (new < conf->max_nr_stripes) {

		if (drop_one_stripe(conf))

			conf->max_nr_stripes--;

		else

			break;

	}

	while (new > conf->max_nr_stripes) {

		if (grow_one_stripe(conf))

			conf->max_nr_stripes++;

		else break;

	}

	return len;

}



static struct md_sysfs_entry

raid6_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,

				raid6_show_stripe_cache_size,

				raid6_store_stripe_cache_size);



static ssize_t

stripe_cache_active_show(mddev_t *mddev, char *page)

{

	raid6_conf_t *conf = mddev_to_conf(mddev);

	if (conf)

		return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));

	else

		return 0;

}



static struct md_sysfs_entry

raid6_stripecache_active = __ATTR_RO(stripe_cache_active);



static struct attribute *raid6_attrs[] =  {

	&raid6_stripecache_size.attr,

	&raid6_stripecache_active.attr,

	NULL,

};

static struct attribute_group raid6_attrs_group = {

	.name = NULL,

	.attrs = raid6_attrs,

};



static int run(mddev_t *mddev)

{

	raid6_conf_t *conf;
@@ -2095,6 +2175,7 @@ static int stop (mddev_t *mddev) 
	shrink_stripes(conf);

	kfree(conf->stripe_hashtbl);

	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/

	sysfs_remove_group(&mddev->kobj, &raid6_attrs_group);

	kfree(conf);

	mddev->private = NULL;

	return 0;