opnsense-src/sys/ofed/include/linux/workqueue.h
Xin LI 5ed3c8af83 According to the documentation, on Linux, cancel_delayed_work() does not
do drain (flush_workqueue() in Linux terms) but instead returns true if
the work was removed before it is run, or false otherwise.

Simulate this by removing the taskqueue_drain() and return the value
derived from taskqueue_cancel()'s return value.

This would solve a witness warning caused by calling taskqueue_drain()
with a non-sleepable lock held, like:

taskqueue_drain with the following non-sleepable locks held:
exclusive rw lle (lle) r = 0 (0xfffffe001450b410) locked @
/usr/src/sys/netinet/in.c:1484
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xffffff848d4f7690
kdb_backtrace() at kdb_backtrace+0x39/frame 0xffffff848d4f7740
witness_warn() at witness_warn+0x4a8/frame 0xffffff848d4f7800
taskqueue_drain() at taskqueue_drain+0x3a/frame 0xffffff848d4f7840
set_timeout() at set_timeout+0x4a/frame 0xffffff848d4f7860
netevent_callback() at netevent_callback+0x16/frame 0xffffff848d4f7870
arpintr() at arpintr+0x9b5/frame 0xffffff848d4f7930

This do not affect kernel without OFED compiled in.

Reported by:	Garrett Cooper <yaneurabeya gmail com>
		(who also tested an earlier version of this patch,
		but bugs are mine)
MFC after:	2 weeks
2013-05-08 17:45:22 +00:00

193 lines
4.9 KiB
C

/*-
* Copyright (c) 2010 Isilon Systems, Inc.
* Copyright (c) 2010 iX Systems, Inc.
* Copyright (c) 2010 Panasas, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _LINUX_WORKQUEUE_H_
#define _LINUX_WORKQUEUE_H_
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <sys/taskqueue.h>
struct workqueue_struct {
struct taskqueue *taskqueue;
};
struct work_struct {
struct task work_task;
struct taskqueue *taskqueue;
void (*fn)(struct work_struct *);
};
struct delayed_work {
struct work_struct work;
struct callout timer;
};
static inline struct delayed_work *
to_delayed_work(struct work_struct *work)
{
return container_of(work, struct delayed_work, work);
}
static inline void
_work_fn(void *context, int pending)
{
struct work_struct *work;
work = context;
work->fn(work);
}
#define INIT_WORK(work, func) \
do { \
(work)->fn = (func); \
(work)->taskqueue = NULL; \
TASK_INIT(&(work)->work_task, 0, _work_fn, (work)); \
} while (0)
#define INIT_DELAYED_WORK(_work, func) \
do { \
INIT_WORK(&(_work)->work, func); \
callout_init(&(_work)->timer, CALLOUT_MPSAFE); \
} while (0)
#define INIT_DELAYED_WORK_DEFERRABLE INIT_DELAYED_WORK
#define schedule_work(work) \
do { \
(work)->taskqueue = taskqueue_thread; \
taskqueue_enqueue(taskqueue_thread, &(work)->work_task); \
} while (0)
#define flush_scheduled_work() flush_taskqueue(taskqueue_thread)
#define queue_work(q, work) \
do { \
(work)->taskqueue = (q)->taskqueue; \
taskqueue_enqueue((q)->taskqueue, &(work)->work_task); \
} while (0)
static inline void
_delayed_work_fn(void *arg)
{
struct delayed_work *work;
work = arg;
taskqueue_enqueue(work->work.taskqueue, &work->work.work_task);
}
static inline int
queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *work,
unsigned long delay)
{
int pending;
pending = work->work.work_task.ta_pending;
work->work.taskqueue = wq->taskqueue;
if (delay != 0)
callout_reset(&work->timer, delay, _delayed_work_fn, work);
else
_delayed_work_fn((void *)work);
return (!pending);
}
static inline struct workqueue_struct *
_create_workqueue_common(char *name, int cpus)
{
struct workqueue_struct *wq;
wq = kmalloc(sizeof(*wq), M_WAITOK);
wq->taskqueue = taskqueue_create((name), M_WAITOK,
taskqueue_thread_enqueue, &wq->taskqueue);
taskqueue_start_threads(&wq->taskqueue, cpus, PWAIT, "%s", name);
return (wq);
}
#define create_singlethread_workqueue(name) \
_create_workqueue_common(name, 1)
#define create_workqueue(name) \
_create_workqueue_common(name, MAXCPU)
static inline void
destroy_workqueue(struct workqueue_struct *wq)
{
taskqueue_free(wq->taskqueue);
kfree(wq);
}
#define flush_workqueue(wq) flush_taskqueue((wq)->taskqueue)
static inline void
_flush_fn(void *context, int pending)
{
}
static inline void
flush_taskqueue(struct taskqueue *tq)
{
struct task flushtask;
PHOLD(curproc);
TASK_INIT(&flushtask, 0, _flush_fn, NULL);
taskqueue_enqueue(tq, &flushtask);
taskqueue_drain(tq, &flushtask);
PRELE(curproc);
}
static inline int
cancel_work_sync(struct work_struct *work)
{
if (work->taskqueue &&
taskqueue_cancel(work->taskqueue, &work->work_task, NULL))
taskqueue_drain(work->taskqueue, &work->work_task);
return 0;
}
/*
* This may leave work running on another CPU as it does on Linux.
*/
static inline int
cancel_delayed_work(struct delayed_work *work)
{
callout_stop(&work->timer);
if (work->work.taskqueue)
return (taskqueue_cancel(work->work.taskqueue,
&work->work.work_task, NULL) == 0);
return 0;
}
#endif /* _LINUX_WORKQUEUE_H_ */