From 8e8d7f13b6d5a93b3d2cf9a4ceaaf923809fd5ac Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 5 Jan 2017 10:38:34 +0000 Subject: afs: Add some tracepoints Add three tracepoints to the AFS filesystem: (1) The afs_recv_data tracepoint logs data segments that are extracted from the data received from the peer through afs_extract_data(). (2) The afs_notify_call tracepoint logs notification from AF_RXRPC of data coming in to an asynchronous call. (3) The afs_cb_call tracepoint logs incoming calls that have had their operation ID extracted and mapped into a supported cache manager service call. To make (3) work, the name strings in the afs_call_type struct objects have to be annotated with __tracepoint_string. This is done with the CM_NAME() macro. Further, the AFS call state enum needs a name so that it can be used to declare parameter types. Signed-off-by: David Howells --- include/trace/events/afs.h | 109 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 include/trace/events/afs.h (limited to 'include') diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h new file mode 100644 index 000000000000..845907b04ff4 --- /dev/null +++ b/include/trace/events/afs.h @@ -0,0 +1,109 @@ +/* AFS tracepoints + * + * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM afs + +#if !defined(_TRACE_AFS_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_AFS_H + +#include + +TRACE_EVENT(afs_recv_data, + TP_PROTO(struct afs_call *call, unsigned count, unsigned offset, + bool want_more, int ret), + + TP_ARGS(call, count, offset, want_more, ret), + + TP_STRUCT__entry( + __field(struct rxrpc_call *, rxcall ) + __field(struct afs_call *, call ) + __field(enum afs_call_state, state ) + __field(unsigned int, count ) + __field(unsigned int, offset ) + __field(unsigned short, unmarshall ) + __field(bool, want_more ) + __field(int, ret ) + ), + + TP_fast_assign( + __entry->rxcall = call->rxcall; + __entry->call = call; + __entry->state = call->state; + __entry->unmarshall = call->unmarshall; + __entry->count = count; + __entry->offset = offset; + __entry->want_more = want_more; + __entry->ret = ret; + ), + + TP_printk("c=%p ac=%p s=%u u=%u %u/%u wm=%u ret=%d", + __entry->rxcall, + __entry->call, + __entry->state, __entry->unmarshall, + __entry->offset, __entry->count, + __entry->want_more, __entry->ret) + ); + +TRACE_EVENT(afs_notify_call, + TP_PROTO(struct rxrpc_call *rxcall, struct afs_call *call), + + TP_ARGS(rxcall, call), + + TP_STRUCT__entry( + __field(struct rxrpc_call *, rxcall ) + __field(struct afs_call *, call ) + __field(enum afs_call_state, state ) + __field(unsigned short, unmarshall ) + ), + + TP_fast_assign( + __entry->rxcall = rxcall; + __entry->call = call; + __entry->state = call->state; + __entry->unmarshall = call->unmarshall; + ), + + TP_printk("c=%p ac=%p s=%u u=%u", + __entry->rxcall, + __entry->call, + __entry->state, __entry->unmarshall) + ); + +TRACE_EVENT(afs_cb_call, + TP_PROTO(struct afs_call *call), + + TP_ARGS(call), + + TP_STRUCT__entry( + __field(struct rxrpc_call *, rxcall ) + __field(struct afs_call *, call ) + __field(const char *, name ) + __field(u32, op ) + ), + + TP_fast_assign( + __entry->rxcall = call->rxcall; + __entry->call = call; + __entry->name = call->type->name; + __entry->op = call->operation_ID; + ), + + TP_printk("c=%p ac=%p %s o=%u", + __entry->rxcall, + __entry->call, + __entry->name, + __entry->op) + ); + +#endif /* _TRACE_AFS_H */ + +/* This part must be outside protection */ +#include -- cgit v1.2.3 From 341f741f04beceebcb30daa12ae2e5e52e64e532 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 5 Jan 2017 10:38:36 +0000 Subject: afs: Refcount the afs_call struct A static checker warning occurs in the AFS filesystem: fs/afs/cmservice.c:155 SRXAFSCB_CallBack() error: dereferencing freed memory 'call' due to the reply being sent before we access the server it points to. The act of sending the reply causes the call to be freed if an error occurs (but not if it doesn't). On top of this, the lifetime handling of afs_call structs is fragile because they get passed around through workqueues without any sort of refcounting. Deal with the issues by: (1) Fix the maybe/maybe not nature of the reply sending functions with regards to whether they release the call struct. (2) Refcount the afs_call struct and sort out places that need to get/put references. (3) Pass a ref through the work queue and release (or pass on) that ref in the work function. Care has to be taken because a work queue may already own a ref to the call. (4) Do the cleaning up in the put function only. (5) Simplify module cleanup by always incrementing afs_outstanding_calls whenever a call is allocated. (6) Set the backlog to 0 with kernel_listen() at the beginning of the process of closing the socket to prevent new incoming calls from occurring and to remove the contribution of preallocated calls from afs_outstanding_calls before we wait on it. A tracepoint is also added to monitor the afs_call refcount and lifetime. Reported-by: Dan Carpenter Signed-off-by: David Howells Fixes: 08e0e7c82eea: "[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC." --- include/trace/events/afs.h | 75 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) (limited to 'include') diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h index 845907b04ff4..8b95c16b7045 100644 --- a/include/trace/events/afs.h +++ b/include/trace/events/afs.h @@ -16,6 +16,51 @@ #include +/* + * Define enums for tracing information. + */ +#ifndef __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY +#define __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY + +enum afs_call_trace { + afs_call_trace_alloc, + afs_call_trace_free, + afs_call_trace_put, + afs_call_trace_wake, + afs_call_trace_work, +}; + +#endif /* end __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY */ + +/* + * Declare tracing information enums and their string mappings for display. + */ +#define afs_call_traces \ + EM(afs_call_trace_alloc, "ALLOC") \ + EM(afs_call_trace_free, "FREE ") \ + EM(afs_call_trace_put, "PUT ") \ + EM(afs_call_trace_wake, "WAKE ") \ + E_(afs_call_trace_work, "WORK ") + +/* + * Export enum symbols via userspace. + */ +#undef EM +#undef E_ +#define EM(a, b) TRACE_DEFINE_ENUM(a); +#define E_(a, b) TRACE_DEFINE_ENUM(a); + +afs_call_traces; + +/* + * Now redefine the EM() and E_() macros to map the enums to the strings that + * will be printed in the output. + */ +#undef EM +#undef E_ +#define EM(a, b) { a, b }, +#define E_(a, b) { a, b } + TRACE_EVENT(afs_recv_data, TP_PROTO(struct afs_call *call, unsigned count, unsigned offset, bool want_more, int ret), @@ -103,6 +148,36 @@ TRACE_EVENT(afs_cb_call, __entry->op) ); +TRACE_EVENT(afs_call, + TP_PROTO(struct afs_call *call, enum afs_call_trace op, + int usage, int outstanding, const void *where), + + TP_ARGS(call, op, usage, outstanding, where), + + TP_STRUCT__entry( + __field(struct afs_call *, call ) + __field(int, op ) + __field(int, usage ) + __field(int, outstanding ) + __field(const void *, where ) + ), + + TP_fast_assign( + __entry->call = call; + __entry->op = op; + __entry->usage = usage; + __entry->outstanding = outstanding; + __entry->where = where; + ), + + TP_printk("c=%p %s u=%d o=%d sp=%pSR", + __entry->call, + __print_symbolic(__entry->op, afs_call_traces), + __entry->usage, + __entry->outstanding, + __entry->where) + ); + #endif /* _TRACE_AFS_H */ /* This part must be outside protection */ -- cgit v1.2.3