From b340a4d4aa18691a6d8b0e747840b0cf30dc01cb Mon Sep 17 00:00:00 2001 From: Steve French Date: Sat, 1 Sep 2018 01:10:17 -0500 Subject: [PATCH] smb3: add tracepoint to catch cases where credit refund of failed op overlaps reconnect Add tracepoint to catch potential cases where a pending operation overlapping a reconnect could fail and incorrectly refund its credits causing the client to think it has more credits available than the server thinks it does. Signed-off-by: Steve French Reviewed-by: Ronnie Sahlberg --- fs/cifs/smb2ops.c | 6 ++++++ fs/cifs/trace.h | 30 ++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 89985a0..831fa60 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -74,6 +74,12 @@ smb2_add_credits(struct TCP_Server_Info *server, const unsigned int add, int *val, rc = 0; spin_lock(&server->req_lock); val = server->ops->get_credits_field(server, optype); + + /* 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); + *val += add; if (*val > 65000) { *val = 65000; /* Don't get near 64K credits, avoid srv bugs */ diff --git a/fs/cifs/trace.h b/fs/cifs/trace.h index d4aed52..43e5bd4 100644 --- a/fs/cifs/trace.h +++ b/fs/cifs/trace.h @@ -486,6 +486,36 @@ DEFINE_EVENT(smb3_reconnect_class, smb3_##name, \ DEFINE_SMB3_RECONNECT_EVENT(reconnect); 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), + TP_STRUCT__entry( + __field(__u64, currmid) + __field(char *, hostname) + __field(int, credits) + ), + TP_fast_assign( + __entry->currmid = currmid; + __entry->hostname = hostname; + __entry->credits = credits; + ), + TP_printk("server=%s current_mid=0x%llx credits=%d", + __entry->hostname, + __entry->currmid, + __entry->credits) +) + +#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)) + +DEFINE_SMB3_CREDIT_EVENT(reconnect_with_invalid_credits); + #endif /* _CIFS_TRACE_H */ #undef TRACE_INCLUDE_PATH -- 2.7.4