cifs: Split the smb3_add_credits tracepoint

BugLink: https://bugs.launchpad.net/bugs/1970977

Split the smb3_add_credits tracepoint to make it more obvious when looking
at the logs which line corresponds to what credit change.  Also add a
tracepoint for credit overflow when it's being added back.

Note that it might be better to add another field to the tracepoint for
the information rather than splitting it.  It would also be useful to store
the MID potentially, though that isn't available when the credits are first
obtained.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: linux-cifs@vger.kernel.org
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
(cherry picked from commit 1ddff77)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Philip Cox <philip.cox@canonical.com>
Acked-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

Author: dhowells

fs/cifs/connect.c

@@ -1044,7 +1044,7 @@ smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 		spin_unlock(&server->req_lock);
 		wake_up(&server->request_q);
 
-		trace_smb3_add_credits(server->CurrentMid,
+		trace_smb3_hdr_credits(server->CurrentMid,
 				server->conn_id, server->hostname, scredits,
 				le16_to_cpu(shdr->CreditRequest), in_flight);
 		cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",

fs/cifs/smb2ops.c

@@ -86,6 +86,9 @@ smb2_add_credits(struct TCP_Server_Info *server,
 	if (*val > 65000) {
 		*val = 65000; /* Don't get near 64K credits, avoid srv bugs */
 		pr_warn_once("server overflowed SMB3 credits\n");
+		trace_smb3_overflow_credits(server->CurrentMid,
+					    server->conn_id, server->hostname, *val,
+					    add, server->in_flight);
 	}
 	server->in_flight--;
 	if (server->in_flight == 0 &&
@@ -251,7 +254,7 @@ smb2_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
 	in_flight = server->in_flight;
 	spin_unlock(&server->req_lock);
 
-	trace_smb3_add_credits(server->CurrentMid,
+	trace_smb3_wait_credits(server->CurrentMid,
 			server->conn_id, server->hostname, scredits, -(credits->value), in_flight);
 	cifs_dbg(FYI, "%s: removed %u credits total=%d\n",
 			__func__, credits->value, scredits);
@@ -300,7 +303,7 @@ smb2_adjust_credits(struct TCP_Server_Info *server,
 	spin_unlock(&server->req_lock);
 	wake_up(&server->request_q);
 
-	trace_smb3_add_credits(server->CurrentMid,
+	trace_smb3_adj_credits(server->CurrentMid,
 			server->conn_id, server->hostname, scredits,
 			credits->value - new_val, in_flight);
 	cifs_dbg(FYI, "%s: adjust added %u credits total=%d\n",
@@ -2509,7 +2512,7 @@ smb2_is_status_pending(char *buf, struct TCP_Server_Info *server)
 		spin_unlock(&server->req_lock);
 		wake_up(&server->request_q);
 
-		trace_smb3_add_credits(server->CurrentMid,
+		trace_smb3_pend_credits(server->CurrentMid,
 				server->conn_id, server->hostname, scredits,
 				le16_to_cpu(shdr->CreditRequest), in_flight);
 		cifs_dbg(FYI, "%s: status pending add %u credits total=%d\n",

fs/cifs/trace.h

@@ -1006,6 +1006,13 @@ DEFINE_SMB3_CREDIT_EVENT(credit_timeout);
 DEFINE_SMB3_CREDIT_EVENT(insufficient_credits);
 DEFINE_SMB3_CREDIT_EVENT(too_many_credits);
 DEFINE_SMB3_CREDIT_EVENT(add_credits);
+DEFINE_SMB3_CREDIT_EVENT(adj_credits);
+DEFINE_SMB3_CREDIT_EVENT(hdr_credits);
+DEFINE_SMB3_CREDIT_EVENT(nblk_credits);
+DEFINE_SMB3_CREDIT_EVENT(pend_credits);
+DEFINE_SMB3_CREDIT_EVENT(wait_credits);
+DEFINE_SMB3_CREDIT_EVENT(waitff_credits);
+DEFINE_SMB3_CREDIT_EVENT(overflow_credits);
 DEFINE_SMB3_CREDIT_EVENT(set_credits);
 
 #endif /* _CIFS_TRACE_H */

fs/cifs/transport.c

@@ -543,7 +543,7 @@ wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
 		in_flight = server->in_flight;
 		spin_unlock(&server->req_lock);
 
-		trace_smb3_add_credits(server->CurrentMid,
+		trace_smb3_nblk_credits(server->CurrentMid,
 				server->conn_id, server->hostname, scredits, -1, in_flight);
 		cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
 				__func__, 1, scredits);
@@ -649,7 +649,7 @@ wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
 			in_flight = server->in_flight;
 			spin_unlock(&server->req_lock);
 
-			trace_smb3_add_credits(server->CurrentMid,
+			trace_smb3_waitff_credits(server->CurrentMid,
 					server->conn_id, server->hostname, scredits,
 					-(num_credits), in_flight);
 			cifs_dbg(FYI, "%s: remove %u credits total=%d\n",