diff options
| author | Shyam Prasad N <sprasad@microsoft.com> | 2020-11-12 08:56:49 -0800 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2020-12-15 16:56:04 -0600 |
| commit | cd7b699b0198a7fc24f6dc79985f6151f589518c (patch) | |
| tree | e6c1784b3762eeb5cd1642c983579a32958bdd5f /fs/cifs/transport.c | |
| parent | 6cf5abbfa8c8a2826d56e38ed1956a0e2f0c85b9 (diff) | |
cifs: Tracepoints and logs for tracing credit changes.
There is at least one suspected bug in crediting changes in cifs.ko
which has come up a few times in the discussions and in a customer
case.
This change adds tracepoints to the code which modifies the server
credit values in any way. The goal is to be able to track the changes
to the credit values of the session to be able to catch when there is
a crediting bug.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs/transport.c')
| -rw-r--r-- | fs/cifs/transport.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 36b2ece43403..e9abb41aa89b 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -527,6 +527,7 @@ wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits, int *credits; int optype; long int t; + int scredits = server->credits; if (timeout < 0) t = MAX_JIFFY_OFFSET; @@ -624,12 +625,18 @@ wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits, /* update # of requests on the wire to server */ if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) { *credits -= num_credits; + scredits = *credits; server->in_flight += num_credits; if (server->in_flight > server->max_in_flight) server->max_in_flight = server->in_flight; *instance = server->reconnect_instance; } spin_unlock(&server->req_lock); + + trace_smb3_add_credits(server->CurrentMid, + server->hostname, scredits, -(num_credits)); + cifs_dbg(FYI, "%s: remove %u credits total=%d\n", + __func__, num_credits, scredits); break; } } @@ -649,10 +656,14 @@ wait_for_compound_request(struct TCP_Server_Info *server, int num, const int flags, unsigned int *instance) { int *credits; + int scredits, sin_flight; credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK); spin_lock(&server->req_lock); + scredits = *credits; + sin_flight = server->in_flight; + if (*credits < num) { /* * Return immediately if not too many requests in flight since @@ -660,6 +671,10 @@ wait_for_compound_request(struct TCP_Server_Info *server, int num, */ if (server->in_flight < num - *credits) { spin_unlock(&server->req_lock); + trace_smb3_insufficient_credits(server->CurrentMid, + server->hostname, scredits, sin_flight); + cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n", + __func__, sin_flight, num, scredits); return -ENOTSUPP; } } |