[PATCH 5.4 72/92] net/smc: Dont call clcsock shutdown twice when smc shutdown
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-11-29 18:30:26
Also in:
lkml
Subsystem:
networking [general], shared memory communications (smc) sockets, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, D. Wythe, Dust Li, Sidraya Jayagond, Wenjia Zhang, Linus Torvalds
From: Tony Lu <tonylu@linux.alibaba.com> [ Upstream commit bacb6c1e47691cda4a95056c21b5487fb7199fcc ] When applications call shutdown() with SHUT_RDWR in userspace, smc_close_active() calls kernel_sock_shutdown(), and it is called twice in smc_shutdown(). This fixes this by checking sk_state before do clcsock shutdown, and avoids missing the application's call of smc_shutdown(). Link: https://lore.kernel.org/linux-s390/1f67548e-cbf6-0dce-82b5-10288a4583bd@linux.ibm.com/ (local) Fixes: 606a63c9783a ("net/smc: Ensure the active closing peer first closes clcsock") Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Reviewed-by: Wen Gu <guwen@linux.alibaba.com> Acked-by: Karsten Graul <redacted> Link: https://lore.kernel.org/r/20211126024134.45693-1-tonylu@linux.alibaba.com (local) Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- net/smc/af_smc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 6b0f09c5b195f..5e1493f8deba7 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c@@ -1658,8 +1658,10 @@ static __poll_t smc_poll(struct file *file, struct socket *sock, static int smc_shutdown(struct socket *sock, int how) { struct sock *sk = sock->sk; + bool do_shutdown = true; struct smc_sock *smc; int rc = -EINVAL; + int old_state; int rc1 = 0; smc = smc_sk(sk);
@@ -1686,7 +1688,11 @@ static int smc_shutdown(struct socket *sock, int how) } switch (how) { case SHUT_RDWR: /* shutdown in both directions */ + old_state = sk->sk_state; rc = smc_close_active(smc); + if (old_state == SMC_ACTIVE && + sk->sk_state == SMC_PEERCLOSEWAIT1) + do_shutdown = false; break; case SHUT_WR: rc = smc_close_shutdown_write(smc);
@@ -1696,7 +1702,7 @@ static int smc_shutdown(struct socket *sock, int how) /* nothing more to do because peer is not involved */ break; } - if (smc->clcsock) + if (do_shutdown && smc->clcsock) rc1 = kernel_sock_shutdown(smc->clcsock, how); /* map sock_shutdown_cmd constants to sk_shutdown value range */ sk->sk_shutdown |= how + 1;
--
2.33.0