Commit 93d2cb6c authored Jun 28, 2017 by Long Li Committed by Steve French Jul 05, 2017

cifs: Do not modify mid entry after submitting I/O in cifs_call_async



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>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>

parent 7e46f090

fs/cifs/transport.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -536,11 +536,14 @@ 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 may 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;

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