[PATCH v2] cifs: Do not modify mid entry after submitting I/O in cifs_call_async

From: Long Li
Date: Wed Jun 28 2017 - 14:57:47 EST


From: Long Li <longli@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
---
fs/cifs/transport.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 47a125e..ba62aaf 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -537,10 +537,10 @@ cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
spin_unlock(&GlobalMid_Lock);


+ 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