From 93d2cb6c82f4d50a1b35b9de379ebb1d022801ac Mon Sep 17 00:00:00 2001 From: Long Li Date: Wed, 28 Jun 2017 15:55:55 -0700 Subject: [PATCH] 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 Reviewed-by: Pavel Shilovsky Signed-off-by: Steve French --- fs/cifs/transport.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 47a125ece11e..7efbab013957 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -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; -- 2.20.1