From: Paulo Alcantara <pc@cjr.nz>
To: linux-cifs@vger.kernel.org, smfrench@gmail.com
Cc: Paulo Alcantara <pc@cjr.nz>
Subject: [PATCH] cifs: allow syscalls to be restarted in __smb_send_rqst()
Date: Sat, 28 Nov 2020 15:57:06 -0300 [thread overview]
Message-ID: <20201128185706.8968-1-pc@cjr.nz> (raw)
A customer has reported that several files in their multi-threaded app
were left with size of 0 because most of the read(2) calls returned
-EINTR and they assumed no bytes were read. Obviously, they could
have fixed it by simply retrying on -EINTR.
We noticed that most of the -EINTR on read(2) were due to real-time
signals sent by glibc to process wide credential changes (SIGRT_1),
and its signal handler had been established with SA_RESTART, in which
case those calls could have been automatically restarted by the
kernel.
Let me the kernel decide to whether or not restart the syscalls when
there is a signal pending in __smb_send_rqst() by returing
-ERESTARTSYS. If it can't, it will return -EINTR anyway.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
---
fs/cifs/transport.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index e27e255d40dd..55853b9ed13d 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -338,10 +338,8 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
if (ssocket == NULL)
return -EAGAIN;
- if (signal_pending(current)) {
- cifs_dbg(FYI, "signal is pending before sending any data\n");
- return -EINTR;
- }
+ if (signal_pending(current))
+ return -ERESTARTSYS;
/* cork the socket */
tcp_sock_set_cork(ssocket->sk, true);
--
2.29.2
next reply other threads:[~2020-11-28 22:04 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-28 18:57 Paulo Alcantara [this message]
[not found] ` <CAH2r5msFYUB7RmWjCxQH8s8Amz4eET8_u8V5qZq3KMhdRFDPrA@mail.gmail.com>
2020-11-29 16:40 ` [PATCH] cifs: allow syscalls to be restarted in __smb_send_rqst() Paulo Alcantara
2020-11-30 10:29 ` Aurélien Aptel
2020-11-30 13:02 ` Paulo Alcantara
2020-11-30 16:24 ` Steve French
2020-11-30 16:34 ` Paulo Alcantara
2020-11-30 20:11 ` Pavel Shilovsky
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