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| author | Coly Li <colyli@suse.de> | 2019-04-25 00:48:38 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-04-24 10:56:28 -0600 |
| commit | bb6d355c2aff42d4075a8e7428dd72cb009d6143 (patch) | |
| tree | 48f743bf4650553de493cb3bfb41edc89441574b /drivers/md | |
| parent | 88c12d42d2bb6e05deb3cfd24d12f6fe80544575 (diff) | |
| download | linux-bb6d355c2aff42d4075a8e7428dd72cb009d6143.tar.gz linux-bb6d355c2aff42d4075a8e7428dd72cb009d6143.tar.bz2 linux-bb6d355c2aff42d4075a8e7428dd72cb009d6143.zip | |
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: Coly Li <colyli@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/bcache/super.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index fde334939545..fa856b2ca7af 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -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; } |