From: Long Li Date: Wed, 28 Jun 2017 22:55:55 +0000 (-0700) Subject: cifs: Do not modify mid entry after submitting I/O in cifs_call_async X-Git-Tag: pci-v4.13-fixes-1~32^2~2 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=93d2cb6c82f4d50a1b35b9de379ebb1d022801ac;p=users%2Fdwmw2%2Flinux.git 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 --- diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 47a125ece11ea..7efbab0139575 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;