9da33de624
ed3e694d "move exit_task_work() past exit_files() et.al" destroyed
the add/exit synchronization we had, the caller itself should ensure
task_work_add() can't race with the exiting task.
However, this is not convenient/simple, and the only user which tries
to do this is buggy (see the next patch). Unless the task is current,
there is simply no way to do this in general.
Change exit_task_work()->task_work_run() to use the dummy "work_exited"
entry to let task_work_add() know it should fail.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20120826191211.GA4228@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
24 lines
578 B
C
24 lines
578 B
C
#ifndef _LINUX_TASK_WORK_H
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#define _LINUX_TASK_WORK_H
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#include <linux/list.h>
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#include <linux/sched.h>
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typedef void (*task_work_func_t)(struct callback_head *);
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static inline void
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init_task_work(struct callback_head *twork, task_work_func_t func)
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{
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twork->func = func;
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}
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int task_work_add(struct task_struct *task, struct callback_head *twork, bool);
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struct callback_head *task_work_cancel(struct task_struct *, task_work_func_t);
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void task_work_run(void);
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static inline void exit_task_work(struct task_struct *task)
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{
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task_work_run();
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}
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#endif /* _LINUX_TASK_WORK_H */
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