switch fput to task_work_add
... and schedule_work() for interrupt/kernel_thread callers
(and yes, now it *is* OK to call from interrupt).
We are guaranteed that __fput() will be done before we return
to userland (or exit). Note that for fput() from a kernel
thread we get an async behaviour; it's almost always OK, but
sometimes you might need to have __fput() completed before
you do anything else. There are two mechanisms for that -
a general barrier (flush_delayed_fput()) and explicit
__fput_sync(). Both should be used with care (as was the
case for fput() from kernel threads all along). See comments
in fs/file_table.c for details.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/file.h b/include/linux/file.h
index 58bf158..a22408b 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -39,4 +39,7 @@
extern void fd_install(unsigned int fd, struct file *file);
+extern void flush_delayed_fput(void);
+extern void __fput_sync(struct file *);
+
#endif /* __LINUX_FILE_H */