diff options
| author | Xiubo Li <xiubli@redhat.com> | 2019-09-19 11:44:27 +0530 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-10-10 09:44:56 -0600 |
| commit | 862488105b84ca744b3d8ff131e0fcfe10644be1 (patch) | |
| tree | b390e422dd7a8fe4014c937b4203afb61298abe6 /drivers/block | |
| parent | 79a85e214d62da9a750cc63ef49483e62abbda81 (diff) | |
nbd: fix possible sysfs duplicate warning
1. nbd_put takes the mutex and drops nbd->ref to 0. It then does
idr_remove and drops the mutex.
2. nbd_genl_connect takes the mutex. idr_find/idr_for_each fails
to find an existing device, so it does nbd_dev_add.
3. just before the nbd_put could call nbd_dev_remove or not finished
totally, but if nbd_dev_add try to add_disk, we can hit:
debugfs: Directory 'nbd1' with parent 'block' already present!
This patch will make sure all the disk add/remove stuff are done
by holding the nbd_index_mutex lock.
Reported-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/nbd.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index ac07e8c94c79..478aa86fc1f2 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -248,8 +248,8 @@ static void nbd_put(struct nbd_device *nbd) if (refcount_dec_and_mutex_lock(&nbd->refs, &nbd_index_mutex)) { idr_remove(&nbd_index_idr, nbd->index); - mutex_unlock(&nbd_index_mutex); nbd_dev_remove(nbd); + mutex_unlock(&nbd_index_mutex); } } |