This is a note to let you know that I've just added the patch titled
net/smc: non blocking recvmsg() return -EAGAIN when no data and signal_pending
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-smc-non-blocking-recvmsg-return-eagain-when-no-d.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9870893a02dd569f574686da2dadd3151d290fc4
Author: Guangguan Wang <guangguan.wang@xxxxxxxxxxxxxxxxx>
Date: Thu May 12 11:08:20 2022 +0800
net/smc: non blocking recvmsg() return -EAGAIN when no data and signal_pending
[ Upstream commit f3c46e41b32b6266cf60b0985c61748f53bf1c61 ]
Non blocking sendmsg will return -EAGAIN when any signal pending
and no send space left, while non blocking recvmsg return -EINTR
when signal pending and no data received. This may makes confused.
As TCP returns -EAGAIN in the conditions described above. Align the
behavior of smc with TCP.
Fixes: 846e344eb722 ("net/smc: add receive timeout check")
Signed-off-by: Guangguan Wang <guangguan.wang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Tony Lu <tonylu@xxxxxxxxxxxxxxxxx>
Acked-by: Karsten Graul <kgraul@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220512030820.73848-1-guangguan.wang@xxxxxxxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c
index cbf58637ee14..0d5146d6d105 100644
--- a/net/smc/smc_rx.c
+++ b/net/smc/smc_rx.c
@@ -145,12 +145,12 @@ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len,
}
break;
}
+ if (!timeo)
+ return -EAGAIN;
if (signal_pending(current)) {
read_done = sock_intr_errno(timeo);
break;
}
- if (!timeo)
- return -EAGAIN;
}
if (!atomic_read(&conn->bytes_to_rcv)) {
