[PATCH] inotify (1/5): split kernel API from userspace support
The following series of patches introduces a kernel API for inotify, making it possible for kernel modules to benefit from inotify's mechanism for watching inodes. With these patches, inotify will maintain for each caller a list of watches (via an embedded struct inotify_watch), where each inotify_watch is associated with a corresponding struct inode. The caller registers an event handler and specifies for which filesystem events their event handler should be called per inotify_watch. Signed-off-by: Amy Griffis <amy.griffis@hp.com> Acked-by: Robert Love <rml@novell.com> Acked-by: John McCutchan <john@johnmccutchan.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Amy Griffis
Al Viro
Родитель
90204e0b7b
Коммит
2d9048e201
24
fs/Kconfig
24
fs/Kconfig
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@ -393,18 +393,30 @@ config INOTIFY
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bool "Inotify file change notification support"
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default y
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---help---
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Say Y here to enable inotify support and the associated system
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calls. Inotify is a file change notification system and a
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replacement for dnotify. Inotify fixes numerous shortcomings in
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dnotify and introduces several new features. It allows monitoring
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of both files and directories via a single open fd. Other features
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include multiple file events, one-shot support, and unmount
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Say Y here to enable inotify support. Inotify is a file change
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notification system and a replacement for dnotify. Inotify fixes
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numerous shortcomings in dnotify and introduces several new features
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including multiple file events, one-shot support, and unmount
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notification.
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For more information, see Documentation/filesystems/inotify.txt
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If unsure, say Y.
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config INOTIFY_USER
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bool "Inotify support for userspace"
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depends on INOTIFY
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default y
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---help---
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Say Y here to enable inotify support for userspace, including the
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associated system calls. Inotify allows monitoring of both files and
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directories via a single open fd. Events are read from the file
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descriptor, which is also select()- and poll()-able.
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For more information, see Documentation/filesystems/inotify.txt
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If unsure, say Y.
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config QUOTA
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bool "Quota support"
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help
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@ -13,6 +13,7 @@ obj-y := open.o read_write.o file_table.o buffer.o bio.o super.o \
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ioprio.o pnode.o drop_caches.o splice.o sync.o
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obj-$(CONFIG_INOTIFY) += inotify.o
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obj-$(CONFIG_INOTIFY_USER) += inotify_user.o
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obj-$(CONFIG_EPOLL) += eventpoll.o
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obj-$(CONFIG_COMPAT) += compat.o compat_ioctl.o
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981
fs/inotify.c
981
fs/inotify.c
Разница между файлами не показана из-за своего большого размера
Загрузить разницу
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@ -0,0 +1,717 @@
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/*
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* fs/inotify_user.c - inotify support for userspace
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*
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* Authors:
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* John McCutchan <ttb@tentacle.dhs.org>
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* Robert Love <rml@novell.com>
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*
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* Copyright (C) 2005 John McCutchan
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* Copyright 2006 Hewlett-Packard Development Company, L.P.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2, or (at your option) any
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* later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/mount.h>
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#include <linux/namei.h>
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#include <linux/poll.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/inotify.h>
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#include <linux/syscalls.h>
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#include <asm/ioctls.h>
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static kmem_cache_t *watch_cachep __read_mostly;
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static kmem_cache_t *event_cachep __read_mostly;
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static struct vfsmount *inotify_mnt __read_mostly;
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/* these are configurable via /proc/sys/fs/inotify/ */
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int inotify_max_user_instances __read_mostly;
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int inotify_max_user_watches __read_mostly;
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int inotify_max_queued_events __read_mostly;
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/*
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* Lock ordering:
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*
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* inotify_dev->up_mutex (ensures we don't re-add the same watch)
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* inode->inotify_mutex (protects inode's watch list)
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* inotify_handle->mutex (protects inotify_handle's watch list)
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* inotify_dev->ev_mutex (protects device's event queue)
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*/
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/*
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* Lifetimes of the main data structures:
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*
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* inotify_device: Lifetime is managed by reference count, from
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* sys_inotify_init() until release. Additional references can bump the count
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* via get_inotify_dev() and drop the count via put_inotify_dev().
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*
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* inotify_user_watch: Lifetime is from create_watch() to the receipt of an
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* IN_IGNORED event from inotify, or when using IN_ONESHOT, to receipt of the
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* first event, or to inotify_destroy().
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*/
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/*
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* struct inotify_device - represents an inotify instance
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*
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* This structure is protected by the mutex 'mutex'.
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*/
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struct inotify_device {
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wait_queue_head_t wq; /* wait queue for i/o */
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struct mutex ev_mutex; /* protects event queue */
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struct mutex up_mutex; /* synchronizes watch updates */
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struct list_head events; /* list of queued events */
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atomic_t count; /* reference count */
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struct user_struct *user; /* user who opened this dev */
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struct inotify_handle *ih; /* inotify handle */
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unsigned int queue_size; /* size of the queue (bytes) */
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unsigned int event_count; /* number of pending events */
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unsigned int max_events; /* maximum number of events */
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};
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/*
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* struct inotify_kernel_event - An inotify event, originating from a watch and
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* queued for user-space. A list of these is attached to each instance of the
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* device. In read(), this list is walked and all events that can fit in the
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* buffer are returned.
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*
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* Protected by dev->ev_mutex of the device in which we are queued.
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*/
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struct inotify_kernel_event {
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struct inotify_event event; /* the user-space event */
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struct list_head list; /* entry in inotify_device's list */
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char *name; /* filename, if any */
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};
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/*
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* struct inotify_user_watch - our version of an inotify_watch, we add
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* a reference to the associated inotify_device.
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*/
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struct inotify_user_watch {
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struct inotify_device *dev; /* associated device */
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struct inotify_watch wdata; /* inotify watch data */
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};
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#ifdef CONFIG_SYSCTL
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#include <linux/sysctl.h>
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static int zero;
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ctl_table inotify_table[] = {
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{
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.ctl_name = INOTIFY_MAX_USER_INSTANCES,
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.procname = "max_user_instances",
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.data = &inotify_max_user_instances,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = &proc_dointvec_minmax,
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.strategy = &sysctl_intvec,
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.extra1 = &zero,
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},
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{
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.ctl_name = INOTIFY_MAX_USER_WATCHES,
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.procname = "max_user_watches",
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.data = &inotify_max_user_watches,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = &proc_dointvec_minmax,
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.strategy = &sysctl_intvec,
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.extra1 = &zero,
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},
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{
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.ctl_name = INOTIFY_MAX_QUEUED_EVENTS,
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.procname = "max_queued_events",
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.data = &inotify_max_queued_events,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = &proc_dointvec_minmax,
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.strategy = &sysctl_intvec,
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.extra1 = &zero
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},
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{ .ctl_name = 0 }
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};
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#endif /* CONFIG_SYSCTL */
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static inline void get_inotify_dev(struct inotify_device *dev)
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{
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atomic_inc(&dev->count);
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}
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static inline void put_inotify_dev(struct inotify_device *dev)
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{
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if (atomic_dec_and_test(&dev->count)) {
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atomic_dec(&dev->user->inotify_devs);
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free_uid(dev->user);
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kfree(dev);
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}
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}
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/*
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* free_inotify_user_watch - cleans up the watch and its references
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*/
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static void free_inotify_user_watch(struct inotify_watch *w)
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{
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struct inotify_user_watch *watch;
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struct inotify_device *dev;
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watch = container_of(w, struct inotify_user_watch, wdata);
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dev = watch->dev;
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atomic_dec(&dev->user->inotify_watches);
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put_inotify_dev(dev);
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kmem_cache_free(watch_cachep, watch);
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}
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/*
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* kernel_event - create a new kernel event with the given parameters
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*
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* This function can sleep.
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*/
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static struct inotify_kernel_event * kernel_event(s32 wd, u32 mask, u32 cookie,
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const char *name)
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{
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struct inotify_kernel_event *kevent;
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kevent = kmem_cache_alloc(event_cachep, GFP_KERNEL);
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if (unlikely(!kevent))
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return NULL;
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/* we hand this out to user-space, so zero it just in case */
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memset(&kevent->event, 0, sizeof(struct inotify_event));
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kevent->event.wd = wd;
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kevent->event.mask = mask;
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kevent->event.cookie = cookie;
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INIT_LIST_HEAD(&kevent->list);
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if (name) {
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size_t len, rem, event_size = sizeof(struct inotify_event);
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/*
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* We need to pad the filename so as to properly align an
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* array of inotify_event structures. Because the structure is
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* small and the common case is a small filename, we just round
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* up to the next multiple of the structure's sizeof. This is
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* simple and safe for all architectures.
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*/
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len = strlen(name) + 1;
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rem = event_size - len;
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if (len > event_size) {
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rem = event_size - (len % event_size);
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if (len % event_size == 0)
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rem = 0;
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}
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kevent->name = kmalloc(len + rem, GFP_KERNEL);
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if (unlikely(!kevent->name)) {
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kmem_cache_free(event_cachep, kevent);
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return NULL;
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}
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memcpy(kevent->name, name, len);
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if (rem)
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memset(kevent->name + len, 0, rem);
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kevent->event.len = len + rem;
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} else {
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kevent->event.len = 0;
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kevent->name = NULL;
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}
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return kevent;
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}
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/*
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* inotify_dev_get_event - return the next event in the given dev's queue
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*
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* Caller must hold dev->ev_mutex.
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*/
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static inline struct inotify_kernel_event *
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inotify_dev_get_event(struct inotify_device *dev)
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{
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return list_entry(dev->events.next, struct inotify_kernel_event, list);
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}
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/*
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* inotify_dev_queue_event - event handler registered with core inotify, adds
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* a new event to the given device
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*
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* Can sleep (calls kernel_event()).
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*/
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static void inotify_dev_queue_event(struct inotify_watch *w, u32 wd, u32 mask,
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u32 cookie, const char *name)
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{
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struct inotify_user_watch *watch;
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struct inotify_device *dev;
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struct inotify_kernel_event *kevent, *last;
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watch = container_of(w, struct inotify_user_watch, wdata);
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dev = watch->dev;
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mutex_lock(&dev->ev_mutex);
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/* we can safely put the watch as we don't reference it while
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* generating the event
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*/
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if (mask & IN_IGNORED || mask & IN_ONESHOT)
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put_inotify_watch(w); /* final put */
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/* coalescing: drop this event if it is a dupe of the previous */
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last = inotify_dev_get_event(dev);
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if (last && last->event.mask == mask && last->event.wd == wd &&
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last->event.cookie == cookie) {
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const char *lastname = last->name;
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if (!name && !lastname)
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goto out;
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||||
if (name && lastname && !strcmp(lastname, name))
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goto out;
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||||
}
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||||
/* the queue overflowed and we already sent the Q_OVERFLOW event */
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||||
if (unlikely(dev->event_count > dev->max_events))
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goto out;
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||||
|
||||
/* if the queue overflows, we need to notify user space */
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if (unlikely(dev->event_count == dev->max_events))
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kevent = kernel_event(-1, IN_Q_OVERFLOW, cookie, NULL);
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else
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kevent = kernel_event(wd, mask, cookie, name);
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|
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if (unlikely(!kevent))
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goto out;
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||||
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/* queue the event and wake up anyone waiting */
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dev->event_count++;
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dev->queue_size += sizeof(struct inotify_event) + kevent->event.len;
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||||
list_add_tail(&kevent->list, &dev->events);
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wake_up_interruptible(&dev->wq);
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out:
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||||
mutex_unlock(&dev->ev_mutex);
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||||
}
|
||||
|
||||
/*
|
||||
* remove_kevent - cleans up and ultimately frees the given kevent
|
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*
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||||
* Caller must hold dev->ev_mutex.
|
||||
*/
|
||||
static void remove_kevent(struct inotify_device *dev,
|
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struct inotify_kernel_event *kevent)
|
||||
{
|
||||
list_del(&kevent->list);
|
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|
||||
dev->event_count--;
|
||||
dev->queue_size -= sizeof(struct inotify_event) + kevent->event.len;
|
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|
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kfree(kevent->name);
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kmem_cache_free(event_cachep, kevent);
|
||||
}
|
||||
|
||||
/*
|
||||
* inotify_dev_event_dequeue - destroy an event on the given device
|
||||
*
|
||||
* Caller must hold dev->ev_mutex.
|
||||
*/
|
||||
static void inotify_dev_event_dequeue(struct inotify_device *dev)
|
||||
{
|
||||
if (!list_empty(&dev->events)) {
|
||||
struct inotify_kernel_event *kevent;
|
||||
kevent = inotify_dev_get_event(dev);
|
||||
remove_kevent(dev, kevent);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* find_inode - resolve a user-given path to a specific inode and return a nd
|
||||
*/
|
||||
static int find_inode(const char __user *dirname, struct nameidata *nd,
|
||||
unsigned flags)
|
||||
{
|
||||
int error;
|
||||
|
||||
error = __user_walk(dirname, flags, nd);
|
||||
if (error)
|
||||
return error;
|
||||
/* you can only watch an inode if you have read permissions on it */
|
||||
error = vfs_permission(nd, MAY_READ);
|
||||
if (error)
|
||||
path_release(nd);
|
||||
return error;
|
||||
}
|
||||
|
||||
/*
|
||||
* create_watch - creates a watch on the given device.
|
||||
*
|
||||
* Callers must hold dev->up_mutex.
|
||||
*/
|
||||
static int create_watch(struct inotify_device *dev, struct inode *inode,
|
||||
u32 mask)
|
||||
{
|
||||
struct inotify_user_watch *watch;
|
||||
int ret;
|
||||
|
||||
if (atomic_read(&dev->user->inotify_watches) >=
|
||||
inotify_max_user_watches)
|
||||
return -ENOSPC;
|
||||
|
||||
watch = kmem_cache_alloc(watch_cachep, GFP_KERNEL);
|
||||
if (unlikely(!watch))
|
||||
return -ENOMEM;
|
||||
|
||||
/* save a reference to device and bump the count to make it official */
|
||||
get_inotify_dev(dev);
|
||||
watch->dev = dev;
|
||||
|
||||
atomic_inc(&dev->user->inotify_watches);
|
||||
|
||||
ret = inotify_add_watch(dev->ih, &watch->wdata, inode, mask);
|
||||
if (ret < 0)
|
||||
free_inotify_user_watch(&watch->wdata);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* Device Interface */
|
||||
|
||||
static unsigned int inotify_poll(struct file *file, poll_table *wait)
|
||||
{
|
||||
struct inotify_device *dev = file->private_data;
|
||||
int ret = 0;
|
||||
|
||||
poll_wait(file, &dev->wq, wait);
|
||||
mutex_lock(&dev->ev_mutex);
|
||||
if (!list_empty(&dev->events))
|
||||
ret = POLLIN | POLLRDNORM;
|
||||
mutex_unlock(&dev->ev_mutex);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t inotify_read(struct file *file, char __user *buf,
|
||||
size_t count, loff_t *pos)
|
||||
{
|
||||
size_t event_size = sizeof (struct inotify_event);
|
||||
struct inotify_device *dev;
|
||||
char __user *start;
|
||||
int ret;
|
||||
DEFINE_WAIT(wait);
|
||||
|
||||
start = buf;
|
||||
dev = file->private_data;
|
||||
|
||||
while (1) {
|
||||
int events;
|
||||
|
||||
prepare_to_wait(&dev->wq, &wait, TASK_INTERRUPTIBLE);
|
||||
|
||||
mutex_lock(&dev->ev_mutex);
|
||||
events = !list_empty(&dev->events);
|
||||
mutex_unlock(&dev->ev_mutex);
|
||||
if (events) {
|
||||
ret = 0;
|
||||
break;
|
||||
}
|
||||
|
||||
if (file->f_flags & O_NONBLOCK) {
|
||||
ret = -EAGAIN;
|
||||
break;
|
||||
}
|
||||
|
||||
if (signal_pending(current)) {
|
||||
ret = -EINTR;
|
||||
break;
|
||||
}
|
||||
|
||||
schedule();
|
||||
}
|
||||
|
||||
finish_wait(&dev->wq, &wait);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
mutex_lock(&dev->ev_mutex);
|
||||
while (1) {
|
||||
struct inotify_kernel_event *kevent;
|
||||
|
||||
ret = buf - start;
|
||||
if (list_empty(&dev->events))
|
||||
break;
|
||||
|
||||
kevent = inotify_dev_get_event(dev);
|
||||
if (event_size + kevent->event.len > count)
|
||||
break;
|
||||
|
||||
if (copy_to_user(buf, &kevent->event, event_size)) {
|
||||
ret = -EFAULT;
|
||||
break;
|
||||
}
|
||||
buf += event_size;
|
||||
count -= event_size;
|
||||
|
||||
if (kevent->name) {
|
||||
if (copy_to_user(buf, kevent->name, kevent->event.len)){
|
||||
ret = -EFAULT;
|
||||
break;
|
||||
}
|
||||
buf += kevent->event.len;
|
||||
count -= kevent->event.len;
|
||||
}
|
||||
|
||||
remove_kevent(dev, kevent);
|
||||
}
|
||||
mutex_unlock(&dev->ev_mutex);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int inotify_release(struct inode *ignored, struct file *file)
|
||||
{
|
||||
struct inotify_device *dev = file->private_data;
|
||||
|
||||
inotify_destroy(dev->ih);
|
||||
|
||||
/* destroy all of the events on this device */
|
||||
mutex_lock(&dev->ev_mutex);
|
||||
while (!list_empty(&dev->events))
|
||||
inotify_dev_event_dequeue(dev);
|
||||
mutex_unlock(&dev->ev_mutex);
|
||||
|
||||
/* free this device: the put matching the get in inotify_init() */
|
||||
put_inotify_dev(dev);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static long inotify_ioctl(struct file *file, unsigned int cmd,
|
||||
unsigned long arg)
|
||||
{
|
||||
struct inotify_device *dev;
|
||||
void __user *p;
|
||||
int ret = -ENOTTY;
|
||||
|
||||
dev = file->private_data;
|
||||
p = (void __user *) arg;
|
||||
|
||||
switch (cmd) {
|
||||
case FIONREAD:
|
||||
ret = put_user(dev->queue_size, (int __user *) p);
|
||||
break;
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static const struct file_operations inotify_fops = {
|
||||
.poll = inotify_poll,
|
||||
.read = inotify_read,
|
||||
.release = inotify_release,
|
||||
.unlocked_ioctl = inotify_ioctl,
|
||||
.compat_ioctl = inotify_ioctl,
|
||||
};
|
||||
|
||||
static const struct inotify_operations inotify_user_ops = {
|
||||
.handle_event = inotify_dev_queue_event,
|
||||
.destroy_watch = free_inotify_user_watch,
|
||||
};
|
||||
|
||||
asmlinkage long sys_inotify_init(void)
|
||||
{
|
||||
struct inotify_device *dev;
|
||||
struct inotify_handle *ih;
|
||||
struct user_struct *user;
|
||||
struct file *filp;
|
||||
int fd, ret;
|
||||
|
||||
fd = get_unused_fd();
|
||||
if (fd < 0)
|
||||
return fd;
|
||||
|
||||
filp = get_empty_filp();
|
||||
if (!filp) {
|
||||
ret = -ENFILE;
|
||||
goto out_put_fd;
|
||||
}
|
||||
|
||||
user = get_uid(current->user);
|
||||
if (unlikely(atomic_read(&user->inotify_devs) >=
|
||||
inotify_max_user_instances)) {
|
||||
ret = -EMFILE;
|
||||
goto out_free_uid;
|
||||
}
|
||||
|
||||
dev = kmalloc(sizeof(struct inotify_device), GFP_KERNEL);
|
||||
if (unlikely(!dev)) {
|
||||
ret = -ENOMEM;
|
||||
goto out_free_uid;
|
||||
}
|
||||
|
||||
ih = inotify_init(&inotify_user_ops);
|
||||
if (unlikely(IS_ERR(ih))) {
|
||||
ret = PTR_ERR(ih);
|
||||
goto out_free_dev;
|
||||
}
|
||||
dev->ih = ih;
|
||||
|
||||
filp->f_op = &inotify_fops;
|
||||
filp->f_vfsmnt = mntget(inotify_mnt);
|
||||
filp->f_dentry = dget(inotify_mnt->mnt_root);
|
||||
filp->f_mapping = filp->f_dentry->d_inode->i_mapping;
|
||||
filp->f_mode = FMODE_READ;
|
||||
filp->f_flags = O_RDONLY;
|
||||
filp->private_data = dev;
|
||||
|
||||
INIT_LIST_HEAD(&dev->events);
|
||||
init_waitqueue_head(&dev->wq);
|
||||
mutex_init(&dev->ev_mutex);
|
||||
mutex_init(&dev->up_mutex);
|
||||
dev->event_count = 0;
|
||||
dev->queue_size = 0;
|
||||
dev->max_events = inotify_max_queued_events;
|
||||
dev->user = user;
|
||||
atomic_set(&dev->count, 0);
|
||||
|
||||
get_inotify_dev(dev);
|
||||
atomic_inc(&user->inotify_devs);
|
||||
fd_install(fd, filp);
|
||||
|
||||
return fd;
|
||||
out_free_dev:
|
||||
kfree(dev);
|
||||
out_free_uid:
|
||||
free_uid(user);
|
||||
put_filp(filp);
|
||||
out_put_fd:
|
||||
put_unused_fd(fd);
|
||||
return ret;
|
||||
}
|
||||
|
||||
asmlinkage long sys_inotify_add_watch(int fd, const char __user *path, u32 mask)
|
||||
{
|
||||
struct inode *inode;
|
||||
struct inotify_device *dev;
|
||||
struct nameidata nd;
|
||||
struct file *filp;
|
||||
int ret, fput_needed;
|
||||
unsigned flags = 0;
|
||||
|
||||
filp = fget_light(fd, &fput_needed);
|
||||
if (unlikely(!filp))
|
||||
return -EBADF;
|
||||
|
||||
/* verify that this is indeed an inotify instance */
|
||||
if (unlikely(filp->f_op != &inotify_fops)) {
|
||||
ret = -EINVAL;
|
||||
goto fput_and_out;
|
||||
}
|
||||
|
||||
if (!(mask & IN_DONT_FOLLOW))
|
||||
flags |= LOOKUP_FOLLOW;
|
||||
if (mask & IN_ONLYDIR)
|
||||
flags |= LOOKUP_DIRECTORY;
|
||||
|
||||
ret = find_inode(path, &nd, flags);
|
||||
if (unlikely(ret))
|
||||
goto fput_and_out;
|
||||
|
||||
/* inode held in place by reference to nd; dev by fget on fd */
|
||||
inode = nd.dentry->d_inode;
|
||||
dev = filp->private_data;
|
||||
|
||||
mutex_lock(&dev->up_mutex);
|
||||
ret = inotify_find_update_watch(dev->ih, inode, mask);
|
||||
if (ret == -ENOENT)
|
||||
ret = create_watch(dev, inode, mask);
|
||||
mutex_unlock(&dev->up_mutex);
|
||||
|
||||
path_release(&nd);
|
||||
fput_and_out:
|
||||
fput_light(filp, fput_needed);
|
||||
return ret;
|
||||
}
|
||||
|
||||
asmlinkage long sys_inotify_rm_watch(int fd, u32 wd)
|
||||
{
|
||||
struct file *filp;
|
||||
struct inotify_device *dev;
|
||||
int ret, fput_needed;
|
||||
|
||||
filp = fget_light(fd, &fput_needed);
|
||||
if (unlikely(!filp))
|
||||
return -EBADF;
|
||||
|
||||
/* verify that this is indeed an inotify instance */
|
||||
if (unlikely(filp->f_op != &inotify_fops)) {
|
||||
ret = -EINVAL;
|
||||
goto out;
|
||||
}
|
||||
|
||||
dev = filp->private_data;
|
||||
|
||||
/* we free our watch data when we get IN_IGNORED */
|
||||
ret = inotify_rm_wd(dev->ih, wd);
|
||||
|
||||
out:
|
||||
fput_light(filp, fput_needed);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static struct super_block *
|
||||
inotify_get_sb(struct file_system_type *fs_type, int flags,
|
||||
const char *dev_name, void *data)
|
||||
{
|
||||
return get_sb_pseudo(fs_type, "inotify", NULL, 0xBAD1DEA);
|
||||
}
|
||||
|
||||
static struct file_system_type inotify_fs_type = {
|
||||
.name = "inotifyfs",
|
||||
.get_sb = inotify_get_sb,
|
||||
.kill_sb = kill_anon_super,
|
||||
};
|
||||
|
||||
/*
|
||||
* inotify_user_setup - Our initialization function. Note that we cannnot return
|
||||
* error because we have compiled-in VFS hooks. So an (unlikely) failure here
|
||||
* must result in panic().
|
||||
*/
|
||||
static int __init inotify_user_setup(void)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = register_filesystem(&inotify_fs_type);
|
||||
if (unlikely(ret))
|
||||
panic("inotify: register_filesystem returned %d!\n", ret);
|
||||
|
||||
inotify_mnt = kern_mount(&inotify_fs_type);
|
||||
if (IS_ERR(inotify_mnt))
|
||||
panic("inotify: kern_mount ret %ld!\n", PTR_ERR(inotify_mnt));
|
||||
|
||||
inotify_max_queued_events = 16384;
|
||||
inotify_max_user_instances = 128;
|
||||
inotify_max_user_watches = 8192;
|
||||
|
||||
watch_cachep = kmem_cache_create("inotify_watch_cache",
|
||||
sizeof(struct inotify_user_watch),
|
||||
0, SLAB_PANIC, NULL, NULL);
|
||||
event_cachep = kmem_cache_create("inotify_event_cache",
|
||||
sizeof(struct inotify_kernel_event),
|
||||
0, SLAB_PANIC, NULL, NULL);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
module_init(inotify_user_setup);
|
||||
|
|
@ -68,8 +68,37 @@ struct inotify_event {
|
|||
#include <linux/dcache.h>
|
||||
#include <linux/fs.h>
|
||||
|
||||
/*
|
||||
* struct inotify_watch - represents a watch request on a specific inode
|
||||
*
|
||||
* h_list is protected by ih->mutex of the associated inotify_handle.
|
||||
* i_list, mask are protected by inode->inotify_mutex of the associated inode.
|
||||
* ih, inode, and wd are never written to once the watch is created.
|
||||
*
|
||||
* Callers must use the established inotify interfaces to access inotify_watch
|
||||
* contents. The content of this structure is private to the inotify
|
||||
* implementation.
|
||||
*/
|
||||
struct inotify_watch {
|
||||
struct list_head h_list; /* entry in inotify_handle's list */
|
||||
struct list_head i_list; /* entry in inode's list */
|
||||
atomic_t count; /* reference count */
|
||||
struct inotify_handle *ih; /* associated inotify handle */
|
||||
struct inode *inode; /* associated inode */
|
||||
__s32 wd; /* watch descriptor */
|
||||
__u32 mask; /* event mask for this watch */
|
||||
};
|
||||
|
||||
struct inotify_operations {
|
||||
void (*handle_event)(struct inotify_watch *, u32, u32, u32,
|
||||
const char *);
|
||||
void (*destroy_watch)(struct inotify_watch *);
|
||||
};
|
||||
|
||||
#ifdef CONFIG_INOTIFY
|
||||
|
||||
/* Kernel API for producing events */
|
||||
|
||||
extern void inotify_d_instantiate(struct dentry *, struct inode *);
|
||||
extern void inotify_d_move(struct dentry *);
|
||||
extern void inotify_inode_queue_event(struct inode *, __u32, __u32,
|
||||
|
|
@ -80,6 +109,18 @@ extern void inotify_unmount_inodes(struct list_head *);
|
|||
extern void inotify_inode_is_dead(struct inode *);
|
||||
extern u32 inotify_get_cookie(void);
|
||||
|
||||
/* Kernel Consumer API */
|
||||
|
||||
extern struct inotify_handle *inotify_init(const struct inotify_operations *);
|
||||
extern void inotify_destroy(struct inotify_handle *);
|
||||
extern __s32 inotify_find_update_watch(struct inotify_handle *, struct inode *,
|
||||
u32);
|
||||
extern __s32 inotify_add_watch(struct inotify_handle *, struct inotify_watch *,
|
||||
struct inode *, __u32);
|
||||
extern int inotify_rm_wd(struct inotify_handle *, __u32);
|
||||
extern void get_inotify_watch(struct inotify_watch *);
|
||||
extern void put_inotify_watch(struct inotify_watch *);
|
||||
|
||||
#else
|
||||
|
||||
static inline void inotify_d_instantiate(struct dentry *dentry,
|
||||
|
|
@ -116,6 +157,41 @@ static inline u32 inotify_get_cookie(void)
|
|||
return 0;
|
||||
}
|
||||
|
||||
static inline struct inotify_handle *inotify_init(const struct inotify_operations *ops)
|
||||
{
|
||||
return ERR_PTR(-EOPNOTSUPP);
|
||||
}
|
||||
|
||||
static inline void inotify_destroy(struct inotify_handle *ih)
|
||||
{
|
||||
}
|
||||
|
||||
static inline __s32 inotify_find_update_watch(struct inotify_handle *ih,
|
||||
struct inode *inode, u32 mask)
|
||||
{
|
||||
return -EOPNOTSUPP;
|
||||
}
|
||||
|
||||
static inline __s32 inotify_add_watch(struct inotify_handle *ih,
|
||||
struct inotify_watch *watch,
|
||||
struct inode *inode, __u32 mask)
|
||||
{
|
||||
return -EOPNOTSUPP;
|
||||
}
|
||||
|
||||
static inline int inotify_rm_wd(struct inotify_handle *ih, __u32 wd)
|
||||
{
|
||||
return -EOPNOTSUPP;
|
||||
}
|
||||
|
||||
static inline void get_inotify_watch(struct inotify_watch *watch)
|
||||
{
|
||||
}
|
||||
|
||||
static inline void put_inotify_watch(struct inotify_watch *watch)
|
||||
{
|
||||
}
|
||||
|
||||
#endif /* CONFIG_INOTIFY */
|
||||
|
||||
#endif /* __KERNEL __ */
|
||||
|
|
|
|||
|
|
@ -494,7 +494,7 @@ struct user_struct {
|
|||
atomic_t processes; /* How many processes does this user have? */
|
||||
atomic_t files; /* How many open files does this user have? */
|
||||
atomic_t sigpending; /* How many pending signals does this user have? */
|
||||
#ifdef CONFIG_INOTIFY
|
||||
#ifdef CONFIG_INOTIFY_USER
|
||||
atomic_t inotify_watches; /* How many inotify watches does this user have? */
|
||||
atomic_t inotify_devs; /* How many inotify devs does this user have opened? */
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -150,7 +150,7 @@ extern ctl_table random_table[];
|
|||
#ifdef CONFIG_UNIX98_PTYS
|
||||
extern ctl_table pty_table[];
|
||||
#endif
|
||||
#ifdef CONFIG_INOTIFY
|
||||
#ifdef CONFIG_INOTIFY_USER
|
||||
extern ctl_table inotify_table[];
|
||||
#endif
|
||||
|
||||
|
|
@ -1028,7 +1028,7 @@ static ctl_table fs_table[] = {
|
|||
.mode = 0644,
|
||||
.proc_handler = &proc_doulongvec_minmax,
|
||||
},
|
||||
#ifdef CONFIG_INOTIFY
|
||||
#ifdef CONFIG_INOTIFY_USER
|
||||
{
|
||||
.ctl_name = FS_INOTIFY,
|
||||
.procname = "inotify",
|
||||
|
|
|
|||
|
|
@ -140,7 +140,7 @@ struct user_struct * alloc_uid(uid_t uid)
|
|||
atomic_set(&new->processes, 0);
|
||||
atomic_set(&new->files, 0);
|
||||
atomic_set(&new->sigpending, 0);
|
||||
#ifdef CONFIG_INOTIFY
|
||||
#ifdef CONFIG_INOTIFY_USER
|
||||
atomic_set(&new->inotify_watches, 0);
|
||||
atomic_set(&new->inotify_devs, 0);
|
||||
#endif
|
||||
|
|
|
|||
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