4.13-stable review patch. If anyone has any objections, please let me know.
------------------ From: Josef Bacik <[email protected]> commit 32e67a3a06b88904155170560b7a63d372b320bd upstream. If you do not set sk_sndtimeo you will get -ERESTARTSYS if there is a pending signal when you enter sendmsg, which we handle properly. However if you set a timeout for your commands we'll set sk_sndtimeo to that timeout, which means that sendmsg will start returning -EINTR instead of -ERESTARTSYS. Fix this by checking either cases and doing the correct thing. Fixes: dc88e34d69d8 ("nbd: set sk->sk_sndtimeo for our sockets") Reported-and-tested-by: Daniel Xu <[email protected]> Signed-off-by: Josef Bacik <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/block/nbd.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -386,6 +386,15 @@ static int sock_xmit(struct nbd_device * return result; } +/* + * Different settings for sk->sk_sndtimeo can result in different return values + * if there is a signal pending when we enter sendmsg, because reasons? + */ +static inline int was_interrupted(int result) +{ + return result == -ERESTARTSYS || result == -EINTR; +} + /* always call with the tx_lock held */ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) { @@ -458,7 +467,7 @@ static int nbd_send_cmd(struct nbd_devic result = sock_xmit(nbd, index, 1, &from, (type == NBD_CMD_WRITE) ? MSG_MORE : 0, &sent); if (result <= 0) { - if (result == -ERESTARTSYS) { + if (was_interrupted(result)) { /* If we havne't sent anything we can just return BUSY, * however if we have sent something we need to make * sure we only allow this req to be sent until we are @@ -502,7 +511,7 @@ send_pages: } result = sock_xmit(nbd, index, 1, &from, flags, &sent); if (result <= 0) { - if (result == -ERESTARTSYS) { + if (was_interrupted(result)) { /* We've already sent the header, we * have no choice but to set pending and * return BUSY.
