[PATCH] md: Add sysfs access to raid6 stripe cache size (35849c75) · Commits · e / devices / android_kernel_sony_msm8994

drivers/md/raid6main.c

+115 −34

Original line number	Original line	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);		list_add_tail(&sh->lru, &conf->inactive_list);
	atomic_dec(&conf->active_stripes);		atomic_dec(&conf->active_stripes);
	if (!conf->inactive_blocked \|\|		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);		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;		conf->inactive_blocked = 1;
	wait_event_lock_irq(conf->wait_for_stripe,		wait_event_lock_irq(conf->wait_for_stripe,
	!list_empty(&conf->inactive_list) &&		!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->inactive_blocked),
	conf->device_lock,		conf->device_lock,
	unplug_slaves(conf->mddev);		unplug_slaves(conf->mddev);
	@@ -302,58 +303,69 @@ static struct stripe_head get_active_stripe(raid6_conf_t conf, sector_t sector
	return sh;		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;		struct stripe_head *sh;
	kmem_cache_t *sc;		sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
	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);
	if (!sh)		if (!sh)
	return 1;		return 0;
	memset(sh, 0, sizeof(sh) + (devs-1)sizeof(struct r5dev));		memset(sh, 0, sizeof(sh) + (conf->raid_disks-1)sizeof(struct r5dev));
	sh->raid_conf = conf;		sh->raid_conf = conf;
	spin_lock_init(&sh->lock);		spin_lock_init(&sh->lock);

	if (grow_buffers(sh, conf->raid_disks)) {		if (grow_buffers(sh, conf->raid_disks)) {
	shrink_buffers(sh, conf->raid_disks);		shrink_buffers(sh, conf->raid_disks);
	kmem_cache_free(sc, sh);		kmem_cache_free(conf->slab_cache, sh);
	return 1;		return 0;
	}		}
	/* we just created an active stripe so... */		/* we just created an active stripe so... */
	atomic_set(&sh->count, 1);		atomic_set(&sh->count, 1);
	atomic_inc(&conf->active_stripes);		atomic_inc(&conf->active_stripes);
	INIT_LIST_HEAD(&sh->lru);		INIT_LIST_HEAD(&sh->lru);
	release_stripe(sh);		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;		return 0;
	}		}

	static void shrink_stripes(raid6_conf_t *conf)		static int drop_one_stripe(raid6_conf_t *conf)
	{		{
	struct stripe_head *sh;		struct stripe_head *sh;

	while (1) {
	spin_lock_irq(&conf->device_lock);		spin_lock_irq(&conf->device_lock);
	sh = get_free_stripe(conf);		sh = get_free_stripe(conf);
	spin_unlock_irq(&conf->device_lock);		spin_unlock_irq(&conf->device_lock);
	if (!sh)		if (!sh)
	break;		return 0;
	if (atomic_read(&sh->count))		if (atomic_read(&sh->count))
	BUG();		BUG();
	shrink_buffers(sh, conf->raid_disks);		shrink_buffers(sh, conf->raid_disks);
	kmem_cache_free(conf->slab_cache, sh);		kmem_cache_free(conf->slab_cache, sh);
	atomic_dec(&conf->active_stripes);		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);		kmem_cache_destroy(conf->slab_cache);
	conf->slab_cache = NULL;		conf->slab_cache = NULL;
	}		}
	@@ -1912,6 +1924,74 @@ static void raid6d (mddev_t *mddev)
	PRINTK("--- raid6d inactive\n");		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)		static int run(mddev_t *mddev)
	{		{
	raid6_conf_t *conf;		raid6_conf_t *conf;
	@@ -2095,6 +2175,7 @@ static int stop (mddev_t *mddev)
	shrink_stripes(conf);		shrink_stripes(conf);
	kfree(conf->stripe_hashtbl);		kfree(conf->stripe_hashtbl);
	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/		blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
			sysfs_remove_group(&mddev->kobj, &raid6_attrs_group);
	kfree(conf);		kfree(conf);
	mddev->private = NULL;		mddev->private = NULL;
	return 0;		return 0;