block: Unregister bdi on last reference drop

Most users will want to unregister bdi when dropping last reference to a
bdi. Only a few users (like block devices) want to play more complex
tricks with bdi registration and unregistration. So unregister bdi when
the last reference to bdi is dropped and just make sure we don't
unregister the bdi the second time if it is already unregistered.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Jan Kara 2017-04-12 12:24:26 +02:00 committed by Jens Axboe
parent baf7a616d5
commit 5af110b2fb
1 changed files with 2 additions and 0 deletions

View File

@ -961,6 +961,8 @@ static void release_bdi(struct kref *ref)
struct backing_dev_info *bdi =
container_of(ref, struct backing_dev_info, refcnt);
if (test_bit(WB_registered, &bdi->wb.state))
bdi_unregister(bdi);
bdi_exit(bdi);
kfree(bdi);
}