Looks good. Reviewed-by: Chaitanya Kulkarni <[email protected]>
On 04/19/2019 11:24 AM, Coly Li wrote: > 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 <[email protected]> > --- > drivers/md/bcache/super.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c > index a435c506edba..83a7cb0e0e45 100644 > --- a/drivers/md/bcache/super.c > +++ b/drivers/md/bcache/super.c > @@ -2191,6 +2191,12 @@ 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 initialzed yet, > + * kobject_put() won't be called and there is no chance to > + * call blkdev_put() to bdev in bch_cache_release(). So we > + * explictly call blkdev_put() here. > + */ > blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); > if (ret == -ENOMEM) > err = "cache_alloc(): -ENOMEM"; > @@ -2331,6 +2337,7 @@ 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 { > @@ -2339,6 +2346,7 @@ 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; > } >
