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Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
72 lines
2.0 KiB
C
72 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* include/linux/eventpoll.h ( Efficient event polling implementation )
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* Copyright (C) 2001,...,2006 Davide Libenzi
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*
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* Davide Libenzi <davidel@xmailserver.org>
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*/
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#ifndef _LINUX_EVENTPOLL_H
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#define _LINUX_EVENTPOLL_H
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#include <uapi/linux/eventpoll.h>
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#include <uapi/linux/kcmp.h>
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/* Forward declarations to avoid compiler errors */
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struct file;
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#ifdef CONFIG_EPOLL
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#ifdef CONFIG_CHECKPOINT_RESTORE
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struct file *get_epoll_tfile_raw_ptr(struct file *file, int tfd, unsigned long toff);
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#endif
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/* Used to initialize the epoll bits inside the "struct file" */
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static inline void eventpoll_init_file(struct file *file)
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{
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INIT_LIST_HEAD(&file->f_ep_links);
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INIT_LIST_HEAD(&file->f_tfile_llink);
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}
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/* Used to release the epoll bits inside the "struct file" */
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void eventpoll_release_file(struct file *file);
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/*
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* This is called from inside fs/file_table.c:__fput() to unlink files
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* from the eventpoll interface. We need to have this facility to cleanup
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* correctly files that are closed without being removed from the eventpoll
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* interface.
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*/
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static inline void eventpoll_release(struct file *file)
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{
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/*
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* Fast check to avoid the get/release of the semaphore. Since
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* we're doing this outside the semaphore lock, it might return
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* false negatives, but we don't care. It'll help in 99.99% of cases
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* to avoid the semaphore lock. False positives simply cannot happen
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* because the file in on the way to be removed and nobody ( but
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* eventpoll ) has still a reference to this file.
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*/
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if (likely(list_empty(&file->f_ep_links)))
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return;
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/*
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* The file is being closed while it is still linked to an epoll
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* descriptor. We need to handle this by correctly unlinking it
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* from its containers.
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*/
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eventpoll_release_file(file);
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}
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#else
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static inline void eventpoll_init_file(struct file *file) {}
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static inline void eventpoll_release(struct file *file) {}
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#endif
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#endif /* #ifndef _LINUX_EVENTPOLL_H */
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