Commit bb6d355c authored by Coly Li's avatar Coly Li Committed by Jens Axboe
Browse files

bcache: Add comments for blkdev_put() in registration code path 



Add comments to explain why in register_bcache() blkdev_put() won't
be called in two location. Add comments to explain why blkdev_put()
must be called in register_cache() when cache_alloc() failed.

Signed-off-by: default avatarColy Li <colyli@suse.de>
Reviewed-by: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 88c12d42

drivers/md/bcache/super.c

+8 −0
Original line number Diff line number Diff line
@@ -2189,6 +2189,12 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page, 


	ret = cache_alloc(ca);

	if (ret != 0) {

		/*

		 * If we failed here, it means ca->kobj is not initialized yet,

		 * kobject_put() won't be called and there is no chance to

		 * call blkdev_put() to bdev in bch_cache_release(). So we

		 * explicitly call blkdev_put() here.

		 */

		blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);

		if (ret == -ENOMEM)

			err = "cache_alloc(): -ENOMEM";
@@ -2329,6 +2335,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, 
		mutex_lock(&bch_register_lock);

		ret = register_bdev(sb, sb_page, bdev, dc);

		mutex_unlock(&bch_register_lock);

		/* blkdev_put() will be called in cached_dev_free() */

		if (ret < 0)

			goto err;

	} else {
@@ -2337,6 +2344,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, 
		if (!ca)

			goto err_close;



		/* blkdev_put() will be called in bch_cache_release() */

		if (register_cache(sb, sb_page, bdev, ca) != 0)

			goto err;

	}

CRA Git | Maintained and supported by SUSTech CRA and CCSE