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@linu... 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 kgraul@linux.ibm.com Link: https://lore.kernel.org/r/20211126024134.45693-1-tonylu@linux.alibaba.com 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 8c71f0929fbb7..f2c907d52812b 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1178,8 +1178,10 @@ static unsigned int 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); @@ -1206,7 +1208,11 @@ 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); @@ -1216,7 +1222,7 @@ 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;