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From: Long Li <longli-Lp/cVzEoVyZiJJESP9tAQJZ3qXmFLfmx@public.gmane.org>
To: Steve French <sfrench-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>,
	linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	samba-technical-w/Ol4Ecudpl8XjKLYN78aQ@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Long Li <longli-0li6OtcxBFHby3iVrkZq2A@public.gmane.org>
Subject: [PATCH v3] cifs: Do not modify mid entry after submitting I/O in cifs_call_async
Date: Wed, 28 Jun 2017 15:02:38 -0700	[thread overview]
Message-ID: <1498687358-7492-1-git-send-email-longli@exchange.microsoft.com> (raw)

From: Long Li <longli-0li6OtcxBFHby3iVrkZq2A@public.gmane.org>

In cifs_call_async, server may respond as soon as I/O is submitted. Because
mid entry is freed on the return path, it should not be modified after I/O
is submitted.

cifs_save_when_sent modifies the sent timestamp in mid entry, and should not
be called after I/O. Call it before I/O.

Signed-off-by: Long Li <longli-0li6OtcxBFHby3iVrkZq2A@public.gmane.org>
---
 fs/cifs/transport.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 47a125e..f49b73f 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -536,11 +536,13 @@ cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
 	list_add_tail(&mid->qhead, &server->pending_mid_q);
 	spin_unlock(&GlobalMid_Lock);
 
-
+	/* Need to store the time in mid before calling I/O. For call_async,
+	 * I/O response can come back and free the mid entry on another thread.
+	 */
+	cifs_save_when_sent(mid);
 	cifs_in_send_inc(server);
 	rc = smb_send_rqst(server, rqst, flags);
 	cifs_in_send_dec(server);
-	cifs_save_when_sent(mid);
 
 	if (rc < 0) {
 		server->sequence_number -= 2;
-- 
2.7.4

WARNING: multiple messages have this Message-ID (diff)
From: Long Li <longli@exchange.microsoft.com>
To: Steve French <sfrench@samba.org>,
	linux-cifs@vger.kernel.org, samba-technical@lists.samba.org,
	linux-kernel@vger.kernel.org
Cc: Long Li <longli@microsoft.com>
Subject: [PATCH v3] cifs: Do not modify mid entry after submitting I/O in cifs_call_async
Date: Wed, 28 Jun 2017 15:02:38 -0700	[thread overview]
Message-ID: <1498687358-7492-1-git-send-email-longli@exchange.microsoft.com> (raw)

From: Long Li <longli@microsoft.com>

In cifs_call_async, server may respond as soon as I/O is submitted. Because
mid entry is freed on the return path, it should not be modified after I/O
is submitted.

cifs_save_when_sent modifies the sent timestamp in mid entry, and should not
be called after I/O. Call it before I/O.

Signed-off-by: Long Li <longli@microsoft.com>
---
 fs/cifs/transport.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 47a125e..f49b73f 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -536,11 +536,13 @@ cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
 	list_add_tail(&mid->qhead, &server->pending_mid_q);
 	spin_unlock(&GlobalMid_Lock);
 
-
+	/* Need to store the time in mid before calling I/O. For call_async,
+	 * I/O response can come back and free the mid entry on another thread.
+	 */
+	cifs_save_when_sent(mid);
 	cifs_in_send_inc(server);
 	rc = smb_send_rqst(server, rqst, flags);
 	cifs_in_send_dec(server);
-	cifs_save_when_sent(mid);
 
 	if (rc < 0) {
 		server->sequence_number -= 2;
-- 
2.7.4

             reply	other threads:[~2017-06-28 22:02 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-28 22:02 Long Li [this message]
2017-06-28 22:02 ` [PATCH v3] cifs: Do not modify mid entry after submitting I/O in cifs_call_async Long Li
     [not found] ` <1498687358-7492-1-git-send-email-longli-Lp/cVzEoVyZiJJESP9tAQJZ3qXmFLfmx@public.gmane.org>
2017-06-28 22:23   ` Pavel Shilovsky
2017-06-28 22:23     ` Pavel Shilovsky

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