smb3: add dynamic tracepoints for flush and close

We only had dynamic tracepoints on errors in flush
and close, but may be helpful to trace enter
and non-error exits for those.  Sample trace examples
(excerpts) from "cp" and "dd" show two of the new
tracepoints.

  cp-22823 [002] .... 123439.179701: smb3_enter: _cifsFileInfo_put: xid=10
  cp-22823 [002] .... 123439.179705: smb3_close_enter: xid=10 sid=0x98871327 tid=0xfcd585ff fid=0xc7f84682
  cp-22823 [002] .... 123439.179711: smb3_cmd_enter: sid=0x98871327 tid=0xfcd585ff cmd=6 mid=43
  cp-22823 [002] .... 123439.180175: smb3_cmd_done: sid=0x98871327 tid=0xfcd585ff cmd=6 mid=43
  cp-22823 [002] .... 123439.180179: smb3_close_done: xid=10 sid=0x98871327 tid=0xfcd585ff fid=0xc7f84682

  dd-22981 [003] .... 123696.946011: smb3_flush_enter: xid=24 sid=0x98871327 tid=0xfcd585ff fid=0x1917736f
  dd-22981 [003] .... 123696.946013: smb3_cmd_enter: sid=0x98871327 tid=0xfcd585ff cmd=7 mid=123
  dd-22981 [003] .... 123696.956639: smb3_cmd_done: sid=0x98871327 tid=0x0 cmd=7 mid=123
  dd-22981 [003] .... 123696.956644: smb3_flush_done: xid=24 sid=0x98871327 tid=0xfcd585ff fid=0x1917736f

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

fs/cifs/smb2pdu.c

@@ -2918,6 +2918,7 @@ SMB2_close_flags(const unsigned int xid, struct cifs_tcon *tcon,
 	rqst.rq_iov = iov;
 	rqst.rq_nvec = 1;
 
+	trace_smb3_close_enter(xid, persistent_fid, tcon->tid, ses->Suid);
 	rc = SMB2_close_init(tcon, &rqst, persistent_fid, volatile_fid);
 	if (rc)
 		goto close_exit;
@@ -2930,7 +2931,9 @@ SMB2_close_flags(const unsigned int xid, struct cifs_tcon *tcon,
 		trace_smb3_close_err(xid, persistent_fid, tcon->tid, ses->Suid,
 				     rc);
 		goto close_exit;
-	}
+	} else
+		trace_smb3_close_done(xid, persistent_fid, tcon->tid,
+				      ses->Suid);
 
 	atomic_dec(&tcon->num_remote_opens);
 
@@ -3353,13 +3356,16 @@ SMB2_flush(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
 	if (rc)
 		goto flush_exit;
 
+	trace_smb3_flush_enter(xid, persistent_fid, tcon->tid, ses->Suid);
 	rc = cifs_send_recv(xid, ses, &rqst, &resp_buftype, flags, &rsp_iov);
 
 	if (rc != 0) {
 		cifs_stats_fail_inc(tcon, SMB2_FLUSH_HE);
 		trace_smb3_flush_err(xid, persistent_fid, tcon->tid, ses->Suid,
 				     rc);
-	}
+	} else
+		trace_smb3_flush_done(xid, persistent_fid, tcon->tid,
+				      ses->Suid);
 
  flush_exit:
 	SMB2_flush_free(&rqst);

fs/cifs/trace.h

@@ -117,6 +117,41 @@ DEFINE_SMB3_RW_DONE_EVENT(falloc_done);
 /*
  * For handle based calls other than read and write, and get/set info
  */
+DECLARE_EVENT_CLASS(smb3_fd_class,
+	TP_PROTO(unsigned int xid,
+		__u64	fid,
+		__u32	tid,
+		__u64	sesid),
+	TP_ARGS(xid, fid, tid, sesid),
+	TP_STRUCT__entry(
+		__field(unsigned int, xid)
+		__field(__u64, fid)
+		__field(__u32, tid)
+		__field(__u64, sesid)
+	),
+	TP_fast_assign(
+		__entry->xid = xid;
+		__entry->fid = fid;
+		__entry->tid = tid;
+		__entry->sesid = sesid;
+	),
+	TP_printk("\txid=%u sid=0x%llx tid=0x%x fid=0x%llx",
+		__entry->xid, __entry->sesid, __entry->tid, __entry->fid)
+)
+
+#define DEFINE_SMB3_FD_EVENT(name)          \
+DEFINE_EVENT(smb3_fd_class, smb3_##name,    \
+	TP_PROTO(unsigned int xid,		\
+		__u64	fid,			\
+		__u32	tid,			\
+		__u64	sesid),			\
+	TP_ARGS(xid, fid, tid, sesid))
+
+DEFINE_SMB3_FD_EVENT(flush_enter);
+DEFINE_SMB3_FD_EVENT(flush_done);
+DEFINE_SMB3_FD_EVENT(close_enter);
+DEFINE_SMB3_FD_EVENT(close_done);
+
 DECLARE_EVENT_CLASS(smb3_fd_err_class,
 	TP_PROTO(unsigned int xid,
 		__u64	fid,