smb3: add dynamic trace point to trace when credits obtained

SMB3 crediting is used for flow control, and it can be useful to
trace for problem determination how many credits were acquired
and for which operation.

Here is an example ("trace-cmd record -e *add_credits"):
cifsd-9522    [010] ....  5995.202712: smb3_add_credits:
	server=localhost current_mid=0x12 credits=373 credits_to_add=10
cifsd-9522    [010] ....  5995.204040: smb3_add_credits:
	server=localhost current_mid=0x15 credits=400 credits_to_add=30

Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 0dfa832..f085fe3 100644 (file)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -72,7 +72,7 @@ smb2_add_credits(struct TCP_Server_Info *server,
        /* eg found case where write overlapping reconnect messed up credits */
        if (((optype & CIFS_OP_MASK) == CIFS_NEG_OP) && (*val != 0))
                trace_smb3_reconnect_with_invalid_credits(server->CurrentMid,
-                       server->hostname, *val);
+                       server->hostname, *val, add);
        if ((instance == 0) || (instance == server->reconnect_instance))
                *val += add;
        else
@@ -121,6 +121,8 @@ smb2_add_credits(struct TCP_Server_Info *server,
                cifs_dbg(FYI, "disabling oplocks\n");
                break;
        default:
+               trace_smb3_add_credits(server->CurrentMid,
+                       server->hostname, rc, add);
                cifs_dbg(FYI, "add %u credits total=%d\n", add, rc);
        }
 }

diff --git a/fs/cifs/trace.h b/fs/cifs/trace.h
index eef4b08..90e0fab 100644 (file)
--- a/fs/cifs/trace.h
+++ b/fs/cifs/trace.h
@@ -878,33 +878,39 @@ DEFINE_SMB3_RECONNECT_EVENT(partial_send_reconnect);
 DECLARE_EVENT_CLASS(smb3_credit_class,
        TP_PROTO(__u64  currmid,
                char *hostname,
-               int credits),
-       TP_ARGS(currmid, hostname, credits),
+               int credits,
+               int credits_to_add),
+       TP_ARGS(currmid, hostname, credits, credits_to_add),
        TP_STRUCT__entry(
                __field(__u64, currmid)
                __field(char *, hostname)
                __field(int, credits)
+               __field(int, credits_to_add)
        ),
        TP_fast_assign(
                __entry->currmid = currmid;
                __entry->hostname = hostname;
                __entry->credits = credits;
+               __entry->credits_to_add = credits_to_add;
        ),
-       TP_printk("server=%s current_mid=0x%llx credits=%d",
+       TP_printk("server=%s current_mid=0x%llx credits=%d credits_to_add=%d",
                __entry->hostname,
                __entry->currmid,
-               __entry->credits)
+               __entry->credits,
+               __entry->credits_to_add)
 )
 
 #define DEFINE_SMB3_CREDIT_EVENT(name)        \
 DEFINE_EVENT(smb3_credit_class, smb3_##name,  \
        TP_PROTO(__u64  currmid,                \
                char *hostname,                 \
-               int  credits),                  \
-       TP_ARGS(currmid, hostname, credits))
+               int  credits,                   \
+               int  credits_to_add),           \
+       TP_ARGS(currmid, hostname, credits, credits_to_add))
 
 DEFINE_SMB3_CREDIT_EVENT(reconnect_with_invalid_credits);
 DEFINE_SMB3_CREDIT_EVENT(credit_timeout);
+DEFINE_SMB3_CREDIT_EVENT(add_credits);
 
 #endif /* _CIFS_TRACE_H */
 

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index ac76324..e27e255 100644 (file)
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -563,7 +563,7 @@ wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
                        cifs_num_waiters_dec(server);
                        if (!rc) {
                                trace_smb3_credit_timeout(server->CurrentMid,
-                                       server->hostname, num_credits);
+                                       server->hostname, num_credits, 0);
                                cifs_server_dbg(VFS, "wait timed out after %d ms\n",
                                         timeout);
                                return -ENOTSUPP;
@@ -604,7 +604,8 @@ wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
                                if (!rc) {
                                        trace_smb3_credit_timeout(
                                                server->CurrentMid,
-                                               server->hostname, num_credits);
+                                               server->hostname, num_credits,
+                                               0);
                                        cifs_server_dbg(VFS, "wait timed out after %d ms\n",
                                                 timeout);
                                        return -ENOTSUPP;