| Message ID | 20190419160509.66298-11-colyli@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bcache: fix journal no-space deadlock | expand |
Looks good. Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> 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 <colyli@suse.de> > --- > 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; > } >
On 4/19/19 6:05 PM, 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 <colyli@suse.de> > --- > 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; > } > Reviewed-by: Hannes Reinecke <hare@suse.com> Cheers, Hannes
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; }
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> --- drivers/md/bcache/super.c | 8 ++++++++ 1 file changed, 8 insertions(+)