nbd requires socket families to support the shutdown method so the nbd recv workqueue can be woken up from its sock_recvmsg call. If the socket does not support the callout we will leave recv works running or get hangs later when the device or module is removed.
This adds a check during socket connection/reconnection to make sure the socket being passed in supports the needed callout. Reported-by: [email protected] Fixes: e9e006f5fcf2 ("nbd: fix max number of supported devs") Signed-off-by: Mike Christie <[email protected]> --- drivers/block/nbd.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 478aa86fc1f2..7bd9e92f6bb7 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -972,6 +972,25 @@ static blk_status_t nbd_queue_rq(struct blk_mq_hw_ctx *hctx, return ret; } +static struct socket *nbd_get_socket(struct nbd_device *nbd, unsigned long fd, + int *err) +{ + struct socket *sock; + + *err = 0; + sock = sockfd_lookup(fd, err); + if (!sock) + return NULL; + + if (sock->ops->shutdown == sock_no_shutdown) { + dev_err(disk_to_dev(nbd->disk), "Unsupported socket: shutdown callout must be supported.\n"); + *err = -EINVAL; + return NULL; + } + + return sock; +} + static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, bool netlink) { @@ -981,7 +1000,7 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, struct nbd_sock *nsock; int err; - sock = sockfd_lookup(arg, &err); + sock = nbd_get_socket(nbd, arg, &err); if (!sock) return err; @@ -1033,7 +1052,7 @@ static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg) int i; int err; - sock = sockfd_lookup(arg, &err); + sock = nbd_get_socket(nbd, arg, &err); if (!sock) return err; -- 2.20.1
