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Commit 3f294f4f authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
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[PATCH] md: add kobject/sysfs support to raid5 



/sys/block/mdX/md/raid5/
contains raid5-related attributes.
Currently
  stripe_cache_size
is number of entries in stripe cache, and is settable.
  stripe_cache_active
is number of active entries, and in only readable.

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 86e6ffdd

drivers/md/raid5.c

+151 −32
Original line number Diff line number Diff line
@@ -293,9 +293,31 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector 
	return sh;

}



static int grow_stripes(raid5_conf_t *conf, int num)

static int grow_one_stripe(raid5_conf_t *conf)

{

	struct stripe_head *sh;

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

	if (!sh)

		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(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(raid5_conf_t *conf, int num)

{

	kmem_cache_t *sc;

	int devs = conf->raid_disks;
@@ -308,43 +330,34 @@ static int grow_stripes(raid5_conf_t *conf, int num) 
		return 1;

	conf->slab_cache = sc;

	while (num--) {

		sh = kmem_cache_alloc(sc, GFP_KERNEL);

		if (!sh)

			return 1;

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

		if (!grow_one_stripe(conf))

			return 1;

	}

		/* 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 0;

}



static void shrink_stripes(raid5_conf_t *conf)

static int drop_one_stripe(raid5_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(raid5_conf_t *conf)

{

	while (drop_one_stripe(conf))

		;



	kmem_cache_destroy(conf->slab_cache);

	conf->slab_cache = NULL;

}
@@ -1714,6 +1727,108 @@ static void raid5d (mddev_t *mddev) 
	PRINTK("--- raid5d inactive\n");

}



struct raid5_sysfs_entry {

	struct attribute attr;

	ssize_t (*show)(raid5_conf_t *, char *);

	ssize_t (*store)(raid5_conf_t *, const char *, ssize_t);

};



static ssize_t

raid5_show_stripe_cache_size(raid5_conf_t *conf, char *page)

{

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

}



static ssize_t

raid5_store_stripe_cache_size(raid5_conf_t *conf, const char *page, ssize_t len)

{

	char *end;

	int new;

	if (len >= PAGE_SIZE)

		return -EINVAL;



	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 raid5_sysfs_entry raid5_stripecache_size = {

	.attr = {.name = "stripe_cache_size", .mode = S_IRUGO | S_IWUSR },

	.show = raid5_show_stripe_cache_size,

	.store = raid5_store_stripe_cache_size,

};



static ssize_t

raid5_show_stripe_cache_active(raid5_conf_t *conf, char *page)

{

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

}



static struct raid5_sysfs_entry raid5_stripecache_active = {

	.attr = {.name = "stripe_cache_active", .mode = S_IRUGO},

	.show = raid5_show_stripe_cache_active,

};



static struct attribute *raid5_default_attrs[] = {

	&raid5_stripecache_size.attr,

	&raid5_stripecache_active.attr,

	NULL,

};



static ssize_t

raid5_attr_show(struct kobject *kobj, struct attribute *attr, char *page)

{

	struct raid5_sysfs_entry *entry = container_of(attr, struct raid5_sysfs_entry, attr);

	raid5_conf_t *conf = container_of(kobj, raid5_conf_t, kobj);



	if (!entry->show)

		return -EIO;

	return entry->show(conf, page);

}



static ssize_t

raid5_attr_store(struct kobject *kobj, struct attribute *attr,

	      const char *page, size_t length)

{

	struct raid5_sysfs_entry *entry = container_of(attr, struct raid5_sysfs_entry, attr);

	raid5_conf_t *conf = container_of(kobj, raid5_conf_t, kobj);



	if (!entry->store)

		return -EIO;

	return entry->store(conf, page, length);

}



static void raid5_free(struct kobject *ko)

{

	raid5_conf_t *conf = container_of(ko, raid5_conf_t, kobj);

	kfree(conf);

}





static struct sysfs_ops raid5_sysfs_ops = {

	.show		= raid5_attr_show,

	.store		= raid5_attr_store,

};



static struct kobj_type raid5_ktype = {

	.release	= raid5_free,

	.sysfs_ops	= &raid5_sysfs_ops,

	.default_attrs	= raid5_default_attrs,

};



static int run(mddev_t *mddev)

{

	raid5_conf_t *conf;
@@ -1855,6 +1970,10 @@ memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + 
	}



	/* Ok, everything is just fine now */

	conf->kobj.parent = kobject_get(&mddev->kobj);

	strcpy(conf->kobj.name, "raid5");

	conf->kobj.ktype = &raid5_ktype;

	kobject_register(&conf->kobj);



	if (mddev->bitmap)

		mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ;
@@ -1888,7 +2007,7 @@ static int stop (mddev_t *mddev) 
	shrink_stripes(conf);

	free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER);

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

	kfree(conf);

	kobject_unregister(&conf->kobj);

	mddev->private = NULL;

	return 0;

}

include/linux/raid/raid5.h

+1 −0
Original line number Diff line number Diff line
@@ -228,6 +228,7 @@ struct raid5_private_data { 
					    * Cleared when a sync completes.

					    */



	struct kobject		kobj;

	/*

	 * Free stripes pool

	 */