[PATCH v4 2/7] nbd: disallow NBD_SET_SOCK on an active device
Yang Erkun <[email protected]>
| Newsgroups | org.kernel.vger.linux-block |
|---|---|
| Message-ID | <[email protected]> |
We cannot add a socket to an already running nbd device, the reconfigure
for netlink can only active an inactive socket. But for ioctl path, we can
call NBD_SET_SOCK after NBD_DO_IT, reject this using nbd->pid which has
been setted when NBD_DO_IT. Besides, it is the root cause for commit
b98e762e3d71 ("nbd: freeze the queue while we're adding connections").
Signed-off-by: Yang Erkun <[email protected]>
---
drivers/block/nbd.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index b1a5acd57426..7ec85f94f742 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1278,6 +1278,13 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
/* Arg will be cast to int, check it to avoid overflow */
if (arg > INT_MAX)
return -EINVAL;
+
+ if (nbd->pid) {
+ dev_err(disk_to_dev(nbd->disk),
+ "Cannot add socket to a running device\n");
+ return -EBUSY;
+ }
+
sock = nbd_get_socket(nbd, arg, &err);
if (!sock)
return err;
--
2.52.0