Commit b340a4d4 authored by Steve French's avatar Steve French
Browse files

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: default avatarSteve French <stfrench@microsoft.com>
Reviewed-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
parent ce7fb50f

fs/cifs/smb2ops.c

+6 −0
Original line number Diff line number Diff line
@@ -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 */

fs/cifs/trace.h

+30 −0
Original line number Diff line number Diff line
@@ -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

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