blob: 4506486974336d6451abc0658de78c0c06bdec9a [file] [log] [blame]
Amy Griffis2d9048e2006-06-01 13:10:59 -07001/*
2 * fs/inotify_user.c - inotify support for userspace
3 *
4 * Authors:
5 * John McCutchan <ttb@tentacle.dhs.org>
6 * Robert Love <rml@novell.com>
7 *
8 * Copyright (C) 2005 John McCutchan
9 * Copyright 2006 Hewlett-Packard Development Company, L.P.
10 *
Eric Paris63c882a2009-05-21 17:02:01 -040011 * Copyright (C) 2009 Eric Paris <Red Hat Inc>
12 * inotify was largely rewriten to make use of the fsnotify infrastructure
13 *
Amy Griffis2d9048e2006-06-01 13:10:59 -070014 * This program is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License as published by the
16 * Free Software Foundation; either version 2, or (at your option) any
17 * later version.
18 *
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
23 */
24
Amy Griffis2d9048e2006-06-01 13:10:59 -070025#include <linux/file.h>
Eric Paris63c882a2009-05-21 17:02:01 -040026#include <linux/fs.h> /* struct inode */
27#include <linux/fsnotify_backend.h>
28#include <linux/idr.h>
29#include <linux/init.h> /* module_init */
Amy Griffis2d9048e2006-06-01 13:10:59 -070030#include <linux/inotify.h>
Eric Paris63c882a2009-05-21 17:02:01 -040031#include <linux/kernel.h> /* roundup() */
Eric Paris63c882a2009-05-21 17:02:01 -040032#include <linux/namei.h> /* LOOKUP_FOLLOW */
Eric Paris63c882a2009-05-21 17:02:01 -040033#include <linux/sched.h> /* struct user */
34#include <linux/slab.h> /* struct kmem_cache */
Amy Griffis2d9048e2006-06-01 13:10:59 -070035#include <linux/syscalls.h>
Eric Paris63c882a2009-05-21 17:02:01 -040036#include <linux/types.h>
Al Viroc44dcc52010-02-11 02:24:46 -050037#include <linux/anon_inodes.h>
Eric Paris63c882a2009-05-21 17:02:01 -040038#include <linux/uaccess.h>
39#include <linux/poll.h>
40#include <linux/wait.h>
41
42#include "inotify.h"
Cyrill Gorcunovbe771962012-12-17 16:05:12 -080043#include "../fdinfo.h"
Amy Griffis2d9048e2006-06-01 13:10:59 -070044
45#include <asm/ioctls.h>
46
Amy Griffis2d9048e2006-06-01 13:10:59 -070047/* these are configurable via /proc/sys/fs/inotify/ */
Harvey Harrison3c828e42008-02-14 19:31:21 -080048static int inotify_max_user_instances __read_mostly;
Harvey Harrison3c828e42008-02-14 19:31:21 -080049static int inotify_max_queued_events __read_mostly;
H Hartley Sweeten0a248872010-05-14 15:35:21 -050050static int inotify_max_user_watches __read_mostly;
Eric Paris63c882a2009-05-21 17:02:01 -040051
52static struct kmem_cache *inotify_inode_mark_cachep __read_mostly;
Amy Griffis2d9048e2006-06-01 13:10:59 -070053
Amy Griffis2d9048e2006-06-01 13:10:59 -070054#ifdef CONFIG_SYSCTL
55
56#include <linux/sysctl.h>
57
58static int zero;
59
Joe Perches92f778d2014-06-06 14:38:04 -070060struct ctl_table inotify_table[] = {
Amy Griffis2d9048e2006-06-01 13:10:59 -070061 {
Amy Griffis2d9048e2006-06-01 13:10:59 -070062 .procname = "max_user_instances",
63 .data = &inotify_max_user_instances,
64 .maxlen = sizeof(int),
65 .mode = 0644,
Eric W. Biederman6d456112009-11-16 03:11:48 -080066 .proc_handler = proc_dointvec_minmax,
Amy Griffis2d9048e2006-06-01 13:10:59 -070067 .extra1 = &zero,
68 },
69 {
Amy Griffis2d9048e2006-06-01 13:10:59 -070070 .procname = "max_user_watches",
71 .data = &inotify_max_user_watches,
72 .maxlen = sizeof(int),
73 .mode = 0644,
Eric W. Biederman6d456112009-11-16 03:11:48 -080074 .proc_handler = proc_dointvec_minmax,
Amy Griffis2d9048e2006-06-01 13:10:59 -070075 .extra1 = &zero,
76 },
77 {
Amy Griffis2d9048e2006-06-01 13:10:59 -070078 .procname = "max_queued_events",
79 .data = &inotify_max_queued_events,
80 .maxlen = sizeof(int),
81 .mode = 0644,
Eric W. Biederman6d456112009-11-16 03:11:48 -080082 .proc_handler = proc_dointvec_minmax,
Amy Griffis2d9048e2006-06-01 13:10:59 -070083 .extra1 = &zero
84 },
Eric W. Biedermanab092032009-11-05 14:25:10 -080085 { }
Amy Griffis2d9048e2006-06-01 13:10:59 -070086};
87#endif /* CONFIG_SYSCTL */
88
Eric Paris63c882a2009-05-21 17:02:01 -040089static inline __u32 inotify_arg_to_mask(u32 arg)
Amy Griffis2d9048e2006-06-01 13:10:59 -070090{
Eric Paris63c882a2009-05-21 17:02:01 -040091 __u32 mask;
92
Eric Paris611da042010-07-28 10:18:37 -040093 /*
94 * everything should accept their own ignored, cares about children,
95 * and should receive events when the inode is unmounted
96 */
97 mask = (FS_IN_IGNORED | FS_EVENT_ON_CHILD | FS_UNMOUNT);
Eric Paris63c882a2009-05-21 17:02:01 -040098
99 /* mask off the flags used to open the fd */
Eric Paris8c1934c2010-07-28 10:18:37 -0400100 mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT | IN_EXCL_UNLINK));
Eric Paris63c882a2009-05-21 17:02:01 -0400101
102 return mask;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700103}
104
Eric Paris63c882a2009-05-21 17:02:01 -0400105static inline u32 inotify_mask_to_arg(__u32 mask)
Amy Griffis2d9048e2006-06-01 13:10:59 -0700106{
Eric Paris63c882a2009-05-21 17:02:01 -0400107 return mask & (IN_ALL_EVENTS | IN_ISDIR | IN_UNMOUNT | IN_IGNORED |
108 IN_Q_OVERFLOW);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700109}
110
Eric Paris63c882a2009-05-21 17:02:01 -0400111/* intofiy userspace file descriptor functions */
Amy Griffis2d9048e2006-06-01 13:10:59 -0700112static unsigned int inotify_poll(struct file *file, poll_table *wait)
113{
Eric Paris63c882a2009-05-21 17:02:01 -0400114 struct fsnotify_group *group = file->private_data;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700115 int ret = 0;
116
Eric Paris63c882a2009-05-21 17:02:01 -0400117 poll_wait(file, &group->notification_waitq, wait);
118 mutex_lock(&group->notification_mutex);
119 if (!fsnotify_notify_queue_is_empty(group))
Amy Griffis2d9048e2006-06-01 13:10:59 -0700120 ret = POLLIN | POLLRDNORM;
Eric Paris63c882a2009-05-21 17:02:01 -0400121 mutex_unlock(&group->notification_mutex);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700122
123 return ret;
124}
125
Jan Kara7053aee2014-01-21 15:48:14 -0800126static int round_event_name_len(struct fsnotify_event *fsn_event)
Jan Karae9fe6902014-01-21 15:48:13 -0800127{
Jan Kara7053aee2014-01-21 15:48:14 -0800128 struct inotify_event_info *event;
129
130 event = INOTIFY_E(fsn_event);
Jan Karae9fe6902014-01-21 15:48:13 -0800131 if (!event->name_len)
132 return 0;
133 return roundup(event->name_len + 1, sizeof(struct inotify_event));
134}
135
Vegard Nossum3632dee2009-01-22 15:29:45 +0100136/*
137 * Get an inotify_kernel_event if one exists and is small
138 * enough to fit in "count". Return an error pointer if
139 * not large enough.
140 *
Eric Paris63c882a2009-05-21 17:02:01 -0400141 * Called with the group->notification_mutex held.
Vegard Nossum3632dee2009-01-22 15:29:45 +0100142 */
Eric Paris63c882a2009-05-21 17:02:01 -0400143static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
144 size_t count)
Vegard Nossum3632dee2009-01-22 15:29:45 +0100145{
146 size_t event_size = sizeof(struct inotify_event);
Eric Paris63c882a2009-05-21 17:02:01 -0400147 struct fsnotify_event *event;
Vegard Nossum3632dee2009-01-22 15:29:45 +0100148
Eric Paris63c882a2009-05-21 17:02:01 -0400149 if (fsnotify_notify_queue_is_empty(group))
Vegard Nossum3632dee2009-01-22 15:29:45 +0100150 return NULL;
151
Jan Kara8ba8fa912014-08-06 16:03:26 -0700152 event = fsnotify_peek_first_event(group);
Eric Paris63c882a2009-05-21 17:02:01 -0400153
Eric Paris5ba08e22010-07-28 10:18:37 -0400154 pr_debug("%s: group=%p event=%p\n", __func__, group, event);
155
Jan Karae9fe6902014-01-21 15:48:13 -0800156 event_size += round_event_name_len(event);
Vegard Nossum3632dee2009-01-22 15:29:45 +0100157 if (event_size > count)
158 return ERR_PTR(-EINVAL);
159
Eric Paris63c882a2009-05-21 17:02:01 -0400160 /* held the notification_mutex the whole time, so this is the
161 * same event we peeked above */
Jan Kara8ba8fa912014-08-06 16:03:26 -0700162 fsnotify_remove_first_event(group);
Eric Paris63c882a2009-05-21 17:02:01 -0400163
164 return event;
Vegard Nossum3632dee2009-01-22 15:29:45 +0100165}
166
167/*
168 * Copy an event to user space, returning how much we copied.
169 *
170 * We already checked that the event size is smaller than the
171 * buffer we had in "get_one_event()" above.
172 */
Eric Paris63c882a2009-05-21 17:02:01 -0400173static ssize_t copy_event_to_user(struct fsnotify_group *group,
Jan Kara7053aee2014-01-21 15:48:14 -0800174 struct fsnotify_event *fsn_event,
Vegard Nossum3632dee2009-01-22 15:29:45 +0100175 char __user *buf)
176{
Eric Paris63c882a2009-05-21 17:02:01 -0400177 struct inotify_event inotify_event;
Jan Kara7053aee2014-01-21 15:48:14 -0800178 struct inotify_event_info *event;
Vegard Nossum3632dee2009-01-22 15:29:45 +0100179 size_t event_size = sizeof(struct inotify_event);
Jan Karae9fe6902014-01-21 15:48:13 -0800180 size_t name_len;
181 size_t pad_name_len;
Vegard Nossum3632dee2009-01-22 15:29:45 +0100182
Jan Kara7053aee2014-01-21 15:48:14 -0800183 pr_debug("%s: group=%p event=%p\n", __func__, group, fsn_event);
Eric Paris5ba08e22010-07-28 10:18:37 -0400184
Jan Kara7053aee2014-01-21 15:48:14 -0800185 event = INOTIFY_E(fsn_event);
Jan Karae9fe6902014-01-21 15:48:13 -0800186 name_len = event->name_len;
Brian Rogersb962e732009-08-28 10:00:05 -0400187 /*
Jan Karae9fe6902014-01-21 15:48:13 -0800188 * round up name length so it is a multiple of event_size
Eric W. Biederman0db501b2009-08-27 03:20:04 -0700189 * plus an extra byte for the terminating '\0'.
190 */
Jan Kara7053aee2014-01-21 15:48:14 -0800191 pad_name_len = round_event_name_len(fsn_event);
Jan Karae9fe6902014-01-21 15:48:13 -0800192 inotify_event.len = pad_name_len;
Jan Kara7053aee2014-01-21 15:48:14 -0800193 inotify_event.mask = inotify_mask_to_arg(fsn_event->mask);
194 inotify_event.wd = event->wd;
Eric Paris63c882a2009-05-21 17:02:01 -0400195 inotify_event.cookie = event->sync_cookie;
196
197 /* send the main event */
198 if (copy_to_user(buf, &inotify_event, event_size))
Vegard Nossum3632dee2009-01-22 15:29:45 +0100199 return -EFAULT;
200
Eric Paris63c882a2009-05-21 17:02:01 -0400201 buf += event_size;
Vegard Nossum3632dee2009-01-22 15:29:45 +0100202
Eric Paris63c882a2009-05-21 17:02:01 -0400203 /*
204 * fsnotify only stores the pathname, so here we have to send the pathname
205 * and then pad that pathname out to a multiple of sizeof(inotify_event)
Jan Karae9fe6902014-01-21 15:48:13 -0800206 * with zeros.
Eric Paris63c882a2009-05-21 17:02:01 -0400207 */
Jan Karae9fe6902014-01-21 15:48:13 -0800208 if (pad_name_len) {
Eric Paris63c882a2009-05-21 17:02:01 -0400209 /* copy the path name */
Jan Kara7053aee2014-01-21 15:48:14 -0800210 if (copy_to_user(buf, event->name, name_len))
Vegard Nossum3632dee2009-01-22 15:29:45 +0100211 return -EFAULT;
Jan Karae9fe6902014-01-21 15:48:13 -0800212 buf += name_len;
Vegard Nossum3632dee2009-01-22 15:29:45 +0100213
Eric W. Biederman0db501b2009-08-27 03:20:04 -0700214 /* fill userspace with 0's */
Jan Karae9fe6902014-01-21 15:48:13 -0800215 if (clear_user(buf, pad_name_len - name_len))
Eric Paris63c882a2009-05-21 17:02:01 -0400216 return -EFAULT;
Jan Karae9fe6902014-01-21 15:48:13 -0800217 event_size += pad_name_len;
Vegard Nossum3632dee2009-01-22 15:29:45 +0100218 }
Eric Paris63c882a2009-05-21 17:02:01 -0400219
Vegard Nossum3632dee2009-01-22 15:29:45 +0100220 return event_size;
221}
222
Amy Griffis2d9048e2006-06-01 13:10:59 -0700223static ssize_t inotify_read(struct file *file, char __user *buf,
224 size_t count, loff_t *pos)
225{
Eric Paris63c882a2009-05-21 17:02:01 -0400226 struct fsnotify_group *group;
227 struct fsnotify_event *kevent;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700228 char __user *start;
229 int ret;
Peter Zijlstrae23738a2014-09-24 10:18:50 +0200230 DEFINE_WAIT_FUNC(wait, woken_wake_function);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700231
232 start = buf;
Eric Paris63c882a2009-05-21 17:02:01 -0400233 group = file->private_data;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700234
Peter Zijlstrae23738a2014-09-24 10:18:50 +0200235 add_wait_queue(&group->notification_waitq, &wait);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700236 while (1) {
Eric Paris63c882a2009-05-21 17:02:01 -0400237 mutex_lock(&group->notification_mutex);
238 kevent = get_one_event(group, count);
239 mutex_unlock(&group->notification_mutex);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700240
Eric Paris5ba08e22010-07-28 10:18:37 -0400241 pr_debug("%s: group=%p kevent=%p\n", __func__, group, kevent);
242
Vegard Nossum3632dee2009-01-22 15:29:45 +0100243 if (kevent) {
244 ret = PTR_ERR(kevent);
245 if (IS_ERR(kevent))
246 break;
Eric Paris63c882a2009-05-21 17:02:01 -0400247 ret = copy_event_to_user(group, kevent, buf);
Jan Kara7053aee2014-01-21 15:48:14 -0800248 fsnotify_destroy_event(group, kevent);
Vegard Nossum3632dee2009-01-22 15:29:45 +0100249 if (ret < 0)
250 break;
251 buf += ret;
252 count -= ret;
253 continue;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700254 }
255
Vegard Nossum3632dee2009-01-22 15:29:45 +0100256 ret = -EAGAIN;
257 if (file->f_flags & O_NONBLOCK)
Amy Griffis2d9048e2006-06-01 13:10:59 -0700258 break;
Eric Paris1ca39ab2012-03-26 13:07:59 -0400259 ret = -ERESTARTSYS;
Vegard Nossum3632dee2009-01-22 15:29:45 +0100260 if (signal_pending(current))
261 break;
262
263 if (start != buf)
264 break;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700265
Peter Zijlstrae23738a2014-09-24 10:18:50 +0200266 wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700267 }
Peter Zijlstrae23738a2014-09-24 10:18:50 +0200268 remove_wait_queue(&group->notification_waitq, &wait);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700269
Vegard Nossum3632dee2009-01-22 15:29:45 +0100270 if (start != buf && ret != -EFAULT)
Amy Griffis2d9048e2006-06-01 13:10:59 -0700271 ret = buf - start;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700272 return ret;
273}
274
275static int inotify_release(struct inode *ignored, struct file *file)
276{
Eric Paris63c882a2009-05-21 17:02:01 -0400277 struct fsnotify_group *group = file->private_data;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700278
Eric Paris5ba08e22010-07-28 10:18:37 -0400279 pr_debug("%s: group=%p\n", __func__, group);
280
Eric Paris63c882a2009-05-21 17:02:01 -0400281 /* free this group, matching get was inotify_init->fsnotify_obtain_group */
Lino Sanfilippod8153d42011-06-14 17:29:45 +0200282 fsnotify_destroy_group(group);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700283
284 return 0;
285}
286
287static long inotify_ioctl(struct file *file, unsigned int cmd,
288 unsigned long arg)
289{
Eric Paris63c882a2009-05-21 17:02:01 -0400290 struct fsnotify_group *group;
Jan Kara7053aee2014-01-21 15:48:14 -0800291 struct fsnotify_event *fsn_event;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700292 void __user *p;
293 int ret = -ENOTTY;
Eric Paris63c882a2009-05-21 17:02:01 -0400294 size_t send_len = 0;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700295
Eric Paris63c882a2009-05-21 17:02:01 -0400296 group = file->private_data;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700297 p = (void __user *) arg;
298
Eric Paris5ba08e22010-07-28 10:18:37 -0400299 pr_debug("%s: group=%p cmd=%u\n", __func__, group, cmd);
300
Amy Griffis2d9048e2006-06-01 13:10:59 -0700301 switch (cmd) {
302 case FIONREAD:
Eric Paris63c882a2009-05-21 17:02:01 -0400303 mutex_lock(&group->notification_mutex);
Jan Kara7053aee2014-01-21 15:48:14 -0800304 list_for_each_entry(fsn_event, &group->notification_list,
305 list) {
Eric Paris63c882a2009-05-21 17:02:01 -0400306 send_len += sizeof(struct inotify_event);
Jan Kara7053aee2014-01-21 15:48:14 -0800307 send_len += round_event_name_len(fsn_event);
Eric Paris63c882a2009-05-21 17:02:01 -0400308 }
309 mutex_unlock(&group->notification_mutex);
310 ret = put_user(send_len, (int __user *) p);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700311 break;
312 }
313
314 return ret;
315}
316
317static const struct file_operations inotify_fops = {
Cyrill Gorcunovbe771962012-12-17 16:05:12 -0800318 .show_fdinfo = inotify_show_fdinfo,
Eric Paris63c882a2009-05-21 17:02:01 -0400319 .poll = inotify_poll,
320 .read = inotify_read,
Eric Paris0a6b6bd2011-10-14 17:43:39 -0400321 .fasync = fsnotify_fasync,
Eric Paris63c882a2009-05-21 17:02:01 -0400322 .release = inotify_release,
323 .unlocked_ioctl = inotify_ioctl,
Amy Griffis2d9048e2006-06-01 13:10:59 -0700324 .compat_ioctl = inotify_ioctl,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200325 .llseek = noop_llseek,
Amy Griffis2d9048e2006-06-01 13:10:59 -0700326};
327
Amy Griffis2d9048e2006-06-01 13:10:59 -0700328
Eric Paris63c882a2009-05-21 17:02:01 -0400329/*
330 * find_inode - resolve a user-given path to a specific inode
331 */
332static int inotify_find_inode(const char __user *dirname, struct path *path, unsigned flags)
333{
334 int error;
335
336 error = user_path_at(AT_FDCWD, dirname, flags, path);
337 if (error)
338 return error;
339 /* you can only watch an inode if you have read permissions on it */
340 error = inode_permission(path->dentry->d_inode, MAY_READ);
341 if (error)
342 path_put(path);
343 return error;
344}
345
Eric Parisb7ba8372009-12-17 20:12:04 -0500346static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock,
Eric Paris000285d2009-12-17 21:24:24 -0500347 struct inotify_inode_mark *i_mark)
Eric Parisb7ba8372009-12-17 20:12:04 -0500348{
349 int ret;
350
Tejun Heo4542da62013-02-27 17:04:50 -0800351 idr_preload(GFP_KERNEL);
352 spin_lock(idr_lock);
Eric Parisb7ba8372009-12-17 20:12:04 -0500353
Jeff Laytona66c04b2013-04-29 16:21:21 -0700354 ret = idr_alloc_cyclic(idr, i_mark, 1, 0, GFP_NOWAIT);
Tejun Heo4542da62013-02-27 17:04:50 -0800355 if (ret >= 0) {
Eric Parisb7ba8372009-12-17 20:12:04 -0500356 /* we added the mark to the idr, take a reference */
Tejun Heo4542da62013-02-27 17:04:50 -0800357 i_mark->wd = ret;
Tejun Heo4542da62013-02-27 17:04:50 -0800358 fsnotify_get_mark(&i_mark->fsn_mark);
359 }
Eric Parisb7ba8372009-12-17 20:12:04 -0500360
Tejun Heo4542da62013-02-27 17:04:50 -0800361 spin_unlock(idr_lock);
362 idr_preload_end();
363 return ret < 0 ? ret : 0;
Eric Parisb7ba8372009-12-17 20:12:04 -0500364}
365
Eric Paris000285d2009-12-17 21:24:24 -0500366static struct inotify_inode_mark *inotify_idr_find_locked(struct fsnotify_group *group,
Eric Parisb7ba8372009-12-17 20:12:04 -0500367 int wd)
368{
369 struct idr *idr = &group->inotify_data.idr;
370 spinlock_t *idr_lock = &group->inotify_data.idr_lock;
Eric Paris000285d2009-12-17 21:24:24 -0500371 struct inotify_inode_mark *i_mark;
Eric Parisb7ba8372009-12-17 20:12:04 -0500372
373 assert_spin_locked(idr_lock);
374
Eric Paris000285d2009-12-17 21:24:24 -0500375 i_mark = idr_find(idr, wd);
376 if (i_mark) {
377 struct fsnotify_mark *fsn_mark = &i_mark->fsn_mark;
Eric Parisb7ba8372009-12-17 20:12:04 -0500378
Eric Paris000285d2009-12-17 21:24:24 -0500379 fsnotify_get_mark(fsn_mark);
Eric Parisb7ba8372009-12-17 20:12:04 -0500380 /* One ref for being in the idr, one ref we just took */
Eric Paris000285d2009-12-17 21:24:24 -0500381 BUG_ON(atomic_read(&fsn_mark->refcnt) < 2);
Eric Parisb7ba8372009-12-17 20:12:04 -0500382 }
383
Eric Paris000285d2009-12-17 21:24:24 -0500384 return i_mark;
Eric Parisb7ba8372009-12-17 20:12:04 -0500385}
386
Eric Paris000285d2009-12-17 21:24:24 -0500387static struct inotify_inode_mark *inotify_idr_find(struct fsnotify_group *group,
Eric Parisb7ba8372009-12-17 20:12:04 -0500388 int wd)
389{
Eric Paris000285d2009-12-17 21:24:24 -0500390 struct inotify_inode_mark *i_mark;
Eric Parisb7ba8372009-12-17 20:12:04 -0500391 spinlock_t *idr_lock = &group->inotify_data.idr_lock;
392
393 spin_lock(idr_lock);
Eric Paris000285d2009-12-17 21:24:24 -0500394 i_mark = inotify_idr_find_locked(group, wd);
Eric Parisb7ba8372009-12-17 20:12:04 -0500395 spin_unlock(idr_lock);
396
Eric Paris000285d2009-12-17 21:24:24 -0500397 return i_mark;
Eric Parisb7ba8372009-12-17 20:12:04 -0500398}
399
400static void do_inotify_remove_from_idr(struct fsnotify_group *group,
Eric Paris000285d2009-12-17 21:24:24 -0500401 struct inotify_inode_mark *i_mark)
Eric Parisb7ba8372009-12-17 20:12:04 -0500402{
403 struct idr *idr = &group->inotify_data.idr;
404 spinlock_t *idr_lock = &group->inotify_data.idr_lock;
Eric Paris000285d2009-12-17 21:24:24 -0500405 int wd = i_mark->wd;
Eric Parisb7ba8372009-12-17 20:12:04 -0500406
407 assert_spin_locked(idr_lock);
408
409 idr_remove(idr, wd);
410
411 /* removed from the idr, drop that ref */
Eric Paris000285d2009-12-17 21:24:24 -0500412 fsnotify_put_mark(&i_mark->fsn_mark);
Eric Parisb7ba8372009-12-17 20:12:04 -0500413}
414
Eric Parisdead5372009-08-24 16:03:35 -0400415/*
416 * Remove the mark from the idr (if present) and drop the reference
417 * on the mark because it was in the idr.
418 */
Eric Paris7e790dd2009-07-07 10:28:24 -0400419static void inotify_remove_from_idr(struct fsnotify_group *group,
Eric Paris000285d2009-12-17 21:24:24 -0500420 struct inotify_inode_mark *i_mark)
Eric Paris7e790dd2009-07-07 10:28:24 -0400421{
Eric Parisb7ba8372009-12-17 20:12:04 -0500422 spinlock_t *idr_lock = &group->inotify_data.idr_lock;
Eric Paris000285d2009-12-17 21:24:24 -0500423 struct inotify_inode_mark *found_i_mark = NULL;
Eric Parisdead5372009-08-24 16:03:35 -0400424 int wd;
Eric Paris7e790dd2009-07-07 10:28:24 -0400425
Eric Parisb7ba8372009-12-17 20:12:04 -0500426 spin_lock(idr_lock);
Eric Paris000285d2009-12-17 21:24:24 -0500427 wd = i_mark->wd;
Eric Parisdead5372009-08-24 16:03:35 -0400428
Eric Parisb7ba8372009-12-17 20:12:04 -0500429 /*
Eric Paris000285d2009-12-17 21:24:24 -0500430 * does this i_mark think it is in the idr? we shouldn't get called
Eric Parisb7ba8372009-12-17 20:12:04 -0500431 * if it wasn't....
432 */
433 if (wd == -1) {
Eric Paris000285d2009-12-17 21:24:24 -0500434 WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p"
435 " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd,
Jan Kara0809ab62014-12-12 16:58:36 -0800436 i_mark->fsn_mark.group, i_mark->fsn_mark.inode);
Eric Parisdead5372009-08-24 16:03:35 -0400437 goto out;
438 }
439
Eric Parisb7ba8372009-12-17 20:12:04 -0500440 /* Lets look in the idr to see if we find it */
Eric Paris000285d2009-12-17 21:24:24 -0500441 found_i_mark = inotify_idr_find_locked(group, wd);
442 if (unlikely(!found_i_mark)) {
443 WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p"
444 " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd,
Jan Kara0809ab62014-12-12 16:58:36 -0800445 i_mark->fsn_mark.group, i_mark->fsn_mark.inode);
Eric Parisb7ba8372009-12-17 20:12:04 -0500446 goto out;
447 }
Eric Parisdead5372009-08-24 16:03:35 -0400448
Eric Parisb7ba8372009-12-17 20:12:04 -0500449 /*
Eric Paris000285d2009-12-17 21:24:24 -0500450 * We found an mark in the idr at the right wd, but it's
451 * not the mark we were told to remove. eparis seriously
Eric Parisb7ba8372009-12-17 20:12:04 -0500452 * fucked up somewhere.
453 */
Eric Paris000285d2009-12-17 21:24:24 -0500454 if (unlikely(found_i_mark != i_mark)) {
455 WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p "
456 "mark->inode=%p found_i_mark=%p found_i_mark->wd=%d "
457 "found_i_mark->group=%p found_i_mark->inode=%p\n",
458 __func__, i_mark, i_mark->wd, i_mark->fsn_mark.group,
Jan Kara0809ab62014-12-12 16:58:36 -0800459 i_mark->fsn_mark.inode, found_i_mark, found_i_mark->wd,
Eric Paris000285d2009-12-17 21:24:24 -0500460 found_i_mark->fsn_mark.group,
Jan Kara0809ab62014-12-12 16:58:36 -0800461 found_i_mark->fsn_mark.inode);
Eric Parisb7ba8372009-12-17 20:12:04 -0500462 goto out;
463 }
Eric Parisdead5372009-08-24 16:03:35 -0400464
Eric Parisb7ba8372009-12-17 20:12:04 -0500465 /*
466 * One ref for being in the idr
467 * one ref held by the caller trying to kill us
468 * one ref grabbed by inotify_idr_find
469 */
Eric Paris000285d2009-12-17 21:24:24 -0500470 if (unlikely(atomic_read(&i_mark->fsn_mark.refcnt) < 3)) {
471 printk(KERN_ERR "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p"
472 " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd,
Jan Kara0809ab62014-12-12 16:58:36 -0800473 i_mark->fsn_mark.group, i_mark->fsn_mark.inode);
Eric Parisb7ba8372009-12-17 20:12:04 -0500474 /* we can't really recover with bad ref cnting.. */
475 BUG();
476 }
477
Eric Paris000285d2009-12-17 21:24:24 -0500478 do_inotify_remove_from_idr(group, i_mark);
Eric Parisdead5372009-08-24 16:03:35 -0400479out:
Eric Parisb7ba8372009-12-17 20:12:04 -0500480 /* match the ref taken by inotify_idr_find_locked() */
Eric Paris000285d2009-12-17 21:24:24 -0500481 if (found_i_mark)
482 fsnotify_put_mark(&found_i_mark->fsn_mark);
483 i_mark->wd = -1;
Eric Parisb7ba8372009-12-17 20:12:04 -0500484 spin_unlock(idr_lock);
Eric Paris7e790dd2009-07-07 10:28:24 -0400485}
Eric Parisdead5372009-08-24 16:03:35 -0400486
Eric Paris63c882a2009-05-21 17:02:01 -0400487/*
Eric Parisdead5372009-08-24 16:03:35 -0400488 * Send IN_IGNORED for this wd, remove this wd from the idr.
Eric Paris63c882a2009-05-21 17:02:01 -0400489 */
Eric Paris000285d2009-12-17 21:24:24 -0500490void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
Eric Paris528da3e2009-06-12 16:04:26 -0400491 struct fsnotify_group *group)
Eric Paris63c882a2009-05-21 17:02:01 -0400492{
Eric Paris000285d2009-12-17 21:24:24 -0500493 struct inotify_inode_mark *i_mark;
Jan Kara7053aee2014-01-21 15:48:14 -0800494
495 /* Queue ignore event for the watch */
496 inotify_handle_event(group, NULL, fsn_mark, NULL, FS_IN_IGNORED,
Jan Kara45a22f42014-02-17 13:09:50 +0100497 NULL, FSNOTIFY_EVENT_NONE, NULL, 0);
Eric Paris63c882a2009-05-21 17:02:01 -0400498
Lino Sanfilippo8b99c3c2012-03-24 23:44:19 +0100499 i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
Eric Paris000285d2009-12-17 21:24:24 -0500500 /* remove this mark from the idr */
501 inotify_remove_from_idr(group, i_mark);
Eric Paris63c882a2009-05-21 17:02:01 -0400502
Eric Paris5549f7c2009-07-07 10:28:23 -0400503 atomic_dec(&group->inotify_data.user->inotify_watches);
Eric Paris63c882a2009-05-21 17:02:01 -0400504}
505
506/* ding dong the mark is dead */
Eric Paris000285d2009-12-17 21:24:24 -0500507static void inotify_free_mark(struct fsnotify_mark *fsn_mark)
Eric Paris63c882a2009-05-21 17:02:01 -0400508{
Eric Paris000285d2009-12-17 21:24:24 -0500509 struct inotify_inode_mark *i_mark;
Eric Paris31ddd322009-12-17 20:12:06 -0500510
Eric Paris000285d2009-12-17 21:24:24 -0500511 i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
Eric Paris63c882a2009-05-21 17:02:01 -0400512
Eric Paris000285d2009-12-17 21:24:24 -0500513 kmem_cache_free(inotify_inode_mark_cachep, i_mark);
Eric Paris63c882a2009-05-21 17:02:01 -0400514}
515
Eric Paris52cef752009-08-24 16:03:35 -0400516static int inotify_update_existing_watch(struct fsnotify_group *group,
517 struct inode *inode,
518 u32 arg)
Eric Paris63c882a2009-05-21 17:02:01 -0400519{
Eric Paris000285d2009-12-17 21:24:24 -0500520 struct fsnotify_mark *fsn_mark;
521 struct inotify_inode_mark *i_mark;
Eric Paris63c882a2009-05-21 17:02:01 -0400522 __u32 old_mask, new_mask;
Eric Paris52cef752009-08-24 16:03:35 -0400523 __u32 mask;
524 int add = (arg & IN_MASK_ADD);
525 int ret;
Eric Paris63c882a2009-05-21 17:02:01 -0400526
Eric Paris63c882a2009-05-21 17:02:01 -0400527 mask = inotify_arg_to_mask(arg);
Eric Paris63c882a2009-05-21 17:02:01 -0400528
Eric Paris5444e292009-12-17 21:24:27 -0500529 fsn_mark = fsnotify_find_inode_mark(group, inode);
Eric Paris000285d2009-12-17 21:24:24 -0500530 if (!fsn_mark)
Eric Paris52cef752009-08-24 16:03:35 -0400531 return -ENOENT;
Eric Paris63c882a2009-05-21 17:02:01 -0400532
Eric Paris000285d2009-12-17 21:24:24 -0500533 i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
Eric Paris75fe2b22009-07-07 10:28:23 -0400534
Eric Paris000285d2009-12-17 21:24:24 -0500535 spin_lock(&fsn_mark->lock);
Eric Paris63c882a2009-05-21 17:02:01 -0400536
Eric Paris000285d2009-12-17 21:24:24 -0500537 old_mask = fsn_mark->mask;
Eric Paris90b1e7a2009-12-17 21:24:33 -0500538 if (add)
539 fsnotify_set_mark_mask_locked(fsn_mark, (fsn_mark->mask | mask));
540 else
541 fsnotify_set_mark_mask_locked(fsn_mark, mask);
542 new_mask = fsn_mark->mask;
Eric Paris63c882a2009-05-21 17:02:01 -0400543
Eric Paris000285d2009-12-17 21:24:24 -0500544 spin_unlock(&fsn_mark->lock);
Eric Paris63c882a2009-05-21 17:02:01 -0400545
546 if (old_mask != new_mask) {
547 /* more bits in old than in new? */
548 int dropped = (old_mask & ~new_mask);
Eric Paris000285d2009-12-17 21:24:24 -0500549 /* more bits in this fsn_mark than the inode's mask? */
Eric Paris63c882a2009-05-21 17:02:01 -0400550 int do_inode = (new_mask & ~inode->i_fsnotify_mask);
Eric Paris63c882a2009-05-21 17:02:01 -0400551
Eric Paris000285d2009-12-17 21:24:24 -0500552 /* update the inode with this new fsn_mark */
Eric Paris63c882a2009-05-21 17:02:01 -0400553 if (dropped || do_inode)
554 fsnotify_recalc_inode_mask(inode);
555
Eric Paris63c882a2009-05-21 17:02:01 -0400556 }
557
Eric Paris52cef752009-08-24 16:03:35 -0400558 /* return the wd */
Eric Paris000285d2009-12-17 21:24:24 -0500559 ret = i_mark->wd;
Eric Paris52cef752009-08-24 16:03:35 -0400560
Eric Parisd0775442009-12-17 21:24:24 -0500561 /* match the get from fsnotify_find_mark() */
Eric Paris000285d2009-12-17 21:24:24 -0500562 fsnotify_put_mark(fsn_mark);
Eric Paris75fe2b22009-07-07 10:28:23 -0400563
Eric Paris52cef752009-08-24 16:03:35 -0400564 return ret;
565}
566
567static int inotify_new_watch(struct fsnotify_group *group,
568 struct inode *inode,
569 u32 arg)
570{
Eric Paris000285d2009-12-17 21:24:24 -0500571 struct inotify_inode_mark *tmp_i_mark;
Eric Paris52cef752009-08-24 16:03:35 -0400572 __u32 mask;
573 int ret;
Eric Parisb7ba8372009-12-17 20:12:04 -0500574 struct idr *idr = &group->inotify_data.idr;
575 spinlock_t *idr_lock = &group->inotify_data.idr_lock;
Eric Paris52cef752009-08-24 16:03:35 -0400576
Eric Paris52cef752009-08-24 16:03:35 -0400577 mask = inotify_arg_to_mask(arg);
Eric Paris52cef752009-08-24 16:03:35 -0400578
Eric Paris000285d2009-12-17 21:24:24 -0500579 tmp_i_mark = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
580 if (unlikely(!tmp_i_mark))
Eric Paris52cef752009-08-24 16:03:35 -0400581 return -ENOMEM;
582
Eric Paris000285d2009-12-17 21:24:24 -0500583 fsnotify_init_mark(&tmp_i_mark->fsn_mark, inotify_free_mark);
584 tmp_i_mark->fsn_mark.mask = mask;
585 tmp_i_mark->wd = -1;
Eric Paris52cef752009-08-24 16:03:35 -0400586
587 ret = -ENOSPC;
588 if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches)
589 goto out_err;
Eric Parisb7ba8372009-12-17 20:12:04 -0500590
Jeff Laytona66c04b2013-04-29 16:21:21 -0700591 ret = inotify_add_to_idr(idr, idr_lock, tmp_i_mark);
Eric Parisb7ba8372009-12-17 20:12:04 -0500592 if (ret)
Eric Paris52cef752009-08-24 16:03:35 -0400593 goto out_err;
594
Eric Paris52cef752009-08-24 16:03:35 -0400595 /* we are on the idr, now get on the inode */
Lino Sanfilippoe1e5a9f2013-07-08 15:59:45 -0700596 ret = fsnotify_add_mark_locked(&tmp_i_mark->fsn_mark, group, inode,
597 NULL, 0);
Eric Paris52cef752009-08-24 16:03:35 -0400598 if (ret) {
599 /* we failed to get on the inode, get off the idr */
Eric Paris000285d2009-12-17 21:24:24 -0500600 inotify_remove_from_idr(group, tmp_i_mark);
Eric Paris52cef752009-08-24 16:03:35 -0400601 goto out_err;
602 }
603
Eric Paris52cef752009-08-24 16:03:35 -0400604 /* increment the number of watches the user has */
605 atomic_inc(&group->inotify_data.user->inotify_watches);
606
Eric Paris000285d2009-12-17 21:24:24 -0500607 /* return the watch descriptor for this new mark */
608 ret = tmp_i_mark->wd;
Eric Paris52cef752009-08-24 16:03:35 -0400609
Eric Paris52cef752009-08-24 16:03:35 -0400610out_err:
Eric Paris000285d2009-12-17 21:24:24 -0500611 /* match the ref from fsnotify_init_mark() */
612 fsnotify_put_mark(&tmp_i_mark->fsn_mark);
Eric Paris52cef752009-08-24 16:03:35 -0400613
614 return ret;
615}
616
617static int inotify_update_watch(struct fsnotify_group *group, struct inode *inode, u32 arg)
618{
619 int ret = 0;
620
Lino Sanfilippoe1e5a9f2013-07-08 15:59:45 -0700621 mutex_lock(&group->mark_mutex);
Eric Paris52cef752009-08-24 16:03:35 -0400622 /* try to update and existing watch with the new arg */
623 ret = inotify_update_existing_watch(group, inode, arg);
624 /* no mark present, try to add a new one */
625 if (ret == -ENOENT)
626 ret = inotify_new_watch(group, inode, arg);
Lino Sanfilippoe1e5a9f2013-07-08 15:59:45 -0700627 mutex_unlock(&group->mark_mutex);
Eric Paris52cef752009-08-24 16:03:35 -0400628
Eric Paris63c882a2009-05-21 17:02:01 -0400629 return ret;
630}
631
Eric Parisd0de4dc2011-04-05 17:20:50 -0400632static struct fsnotify_group *inotify_new_group(unsigned int max_events)
Eric Paris63c882a2009-05-21 17:02:01 -0400633{
634 struct fsnotify_group *group;
Jan Karaff57cd52014-02-21 19:14:11 +0100635 struct inotify_event_info *oevent;
Eric Paris63c882a2009-05-21 17:02:01 -0400636
Eric Paris0d2e2a12009-12-17 21:24:22 -0500637 group = fsnotify_alloc_group(&inotify_fsnotify_ops);
Eric Paris63c882a2009-05-21 17:02:01 -0400638 if (IS_ERR(group))
639 return group;
640
Jan Karaff57cd52014-02-21 19:14:11 +0100641 oevent = kmalloc(sizeof(struct inotify_event_info), GFP_KERNEL);
642 if (unlikely(!oevent)) {
643 fsnotify_destroy_group(group);
644 return ERR_PTR(-ENOMEM);
645 }
646 group->overflow_event = &oevent->fse;
647 fsnotify_init_event(group->overflow_event, NULL, FS_Q_OVERFLOW);
648 oevent->wd = -1;
649 oevent->sync_cookie = 0;
650 oevent->name_len = 0;
651
Eric Paris63c882a2009-05-21 17:02:01 -0400652 group->max_events = max_events;
653
654 spin_lock_init(&group->inotify_data.idr_lock);
655 idr_init(&group->inotify_data.idr);
Eric Parisd0de4dc2011-04-05 17:20:50 -0400656 group->inotify_data.user = get_current_user();
657
658 if (atomic_inc_return(&group->inotify_data.user->inotify_devs) >
659 inotify_max_user_instances) {
Lino Sanfilippod8153d42011-06-14 17:29:45 +0200660 fsnotify_destroy_group(group);
Eric Parisd0de4dc2011-04-05 17:20:50 -0400661 return ERR_PTR(-EMFILE);
662 }
Eric Paris63c882a2009-05-21 17:02:01 -0400663
664 return group;
665}
666
667
668/* inotify syscalls */
Heiko Carstens938bb9f2009-01-14 14:14:30 +0100669SYSCALL_DEFINE1(inotify_init1, int, flags)
Amy Griffis2d9048e2006-06-01 13:10:59 -0700670{
Eric Paris63c882a2009-05-21 17:02:01 -0400671 struct fsnotify_group *group;
Al Viroc44dcc52010-02-11 02:24:46 -0500672 int ret;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700673
Ulrich Dreppere38b36f2008-07-23 21:29:42 -0700674 /* Check the IN_* constants for consistency. */
675 BUILD_BUG_ON(IN_CLOEXEC != O_CLOEXEC);
676 BUILD_BUG_ON(IN_NONBLOCK != O_NONBLOCK);
677
Ulrich Drepper510df2d2008-07-23 21:29:41 -0700678 if (flags & ~(IN_CLOEXEC | IN_NONBLOCK))
Ulrich Drepper40065532008-07-23 21:29:32 -0700679 return -EINVAL;
680
Eric Paris63c882a2009-05-21 17:02:01 -0400681 /* fsnotify_obtain_group took a reference to group, we put this when we kill the file in the end */
Eric Parisd0de4dc2011-04-05 17:20:50 -0400682 group = inotify_new_group(inotify_max_queued_events);
683 if (IS_ERR(group))
684 return PTR_ERR(group);
Al Viro825f9692009-08-05 18:35:21 +0400685
Al Viroc44dcc52010-02-11 02:24:46 -0500686 ret = anon_inode_getfd("inotify", &inotify_fops, group,
687 O_RDONLY | flags);
Eric Parisd0de4dc2011-04-05 17:20:50 -0400688 if (ret < 0)
Lino Sanfilippod8153d42011-06-14 17:29:45 +0200689 fsnotify_destroy_group(group);
Al Viro825f9692009-08-05 18:35:21 +0400690
Amy Griffis2d9048e2006-06-01 13:10:59 -0700691 return ret;
692}
693
Heiko Carstens938bb9f2009-01-14 14:14:30 +0100694SYSCALL_DEFINE0(inotify_init)
Ulrich Drepper40065532008-07-23 21:29:32 -0700695{
696 return sys_inotify_init1(0);
697}
698
Heiko Carstens2e4d0922009-01-14 14:14:31 +0100699SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname,
700 u32, mask)
Amy Griffis2d9048e2006-06-01 13:10:59 -0700701{
Eric Paris63c882a2009-05-21 17:02:01 -0400702 struct fsnotify_group *group;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700703 struct inode *inode;
Al Viro2d8f3032008-07-22 09:59:21 -0400704 struct path path;
Al Viro2903ff02012-08-28 12:52:22 -0400705 struct fd f;
706 int ret;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700707 unsigned flags = 0;
708
Zhao Hongjiang04df32f2013-04-30 15:26:46 -0700709 /* don't allow invalid bits: we don't want flags set */
710 if (unlikely(!(mask & ALL_INOTIFY_BITS)))
711 return -EINVAL;
712
Al Viro2903ff02012-08-28 12:52:22 -0400713 f = fdget(fd);
714 if (unlikely(!f.file))
Amy Griffis2d9048e2006-06-01 13:10:59 -0700715 return -EBADF;
716
717 /* verify that this is indeed an inotify instance */
Al Viro2903ff02012-08-28 12:52:22 -0400718 if (unlikely(f.file->f_op != &inotify_fops)) {
Amy Griffis2d9048e2006-06-01 13:10:59 -0700719 ret = -EINVAL;
720 goto fput_and_out;
721 }
722
723 if (!(mask & IN_DONT_FOLLOW))
724 flags |= LOOKUP_FOLLOW;
725 if (mask & IN_ONLYDIR)
726 flags |= LOOKUP_DIRECTORY;
727
Eric Paris63c882a2009-05-21 17:02:01 -0400728 ret = inotify_find_inode(pathname, &path, flags);
729 if (ret)
Amy Griffis2d9048e2006-06-01 13:10:59 -0700730 goto fput_and_out;
731
Eric Paris63c882a2009-05-21 17:02:01 -0400732 /* inode held in place by reference to path; group by fget on fd */
Al Viro2d8f3032008-07-22 09:59:21 -0400733 inode = path.dentry->d_inode;
Al Viro2903ff02012-08-28 12:52:22 -0400734 group = f.file->private_data;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700735
Eric Paris63c882a2009-05-21 17:02:01 -0400736 /* create/update an inode mark */
737 ret = inotify_update_watch(group, inode, mask);
Al Viro2d8f3032008-07-22 09:59:21 -0400738 path_put(&path);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700739fput_and_out:
Al Viro2903ff02012-08-28 12:52:22 -0400740 fdput(f);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700741 return ret;
742}
743
Heiko Carstens2e4d0922009-01-14 14:14:31 +0100744SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd)
Amy Griffis2d9048e2006-06-01 13:10:59 -0700745{
Eric Paris63c882a2009-05-21 17:02:01 -0400746 struct fsnotify_group *group;
Eric Paris000285d2009-12-17 21:24:24 -0500747 struct inotify_inode_mark *i_mark;
Al Viro2903ff02012-08-28 12:52:22 -0400748 struct fd f;
749 int ret = 0;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700750
Al Viro2903ff02012-08-28 12:52:22 -0400751 f = fdget(fd);
752 if (unlikely(!f.file))
Amy Griffis2d9048e2006-06-01 13:10:59 -0700753 return -EBADF;
754
755 /* verify that this is indeed an inotify instance */
Eric Parisb7ba8372009-12-17 20:12:04 -0500756 ret = -EINVAL;
Al Viro2903ff02012-08-28 12:52:22 -0400757 if (unlikely(f.file->f_op != &inotify_fops))
Amy Griffis2d9048e2006-06-01 13:10:59 -0700758 goto out;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700759
Al Viro2903ff02012-08-28 12:52:22 -0400760 group = f.file->private_data;
Amy Griffis2d9048e2006-06-01 13:10:59 -0700761
Eric Parisb7ba8372009-12-17 20:12:04 -0500762 ret = -EINVAL;
Eric Paris000285d2009-12-17 21:24:24 -0500763 i_mark = inotify_idr_find(group, wd);
764 if (unlikely(!i_mark))
Eric Paris63c882a2009-05-21 17:02:01 -0400765 goto out;
Eric Paris63c882a2009-05-21 17:02:01 -0400766
Eric Parisb7ba8372009-12-17 20:12:04 -0500767 ret = 0;
768
Lino Sanfilippoe2a29942011-06-14 17:29:51 +0200769 fsnotify_destroy_mark(&i_mark->fsn_mark, group);
Eric Parisb7ba8372009-12-17 20:12:04 -0500770
771 /* match ref taken by inotify_idr_find */
Eric Paris000285d2009-12-17 21:24:24 -0500772 fsnotify_put_mark(&i_mark->fsn_mark);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700773
774out:
Al Viro2903ff02012-08-28 12:52:22 -0400775 fdput(f);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700776 return ret;
777}
778
Amy Griffis2d9048e2006-06-01 13:10:59 -0700779/*
Justin P. Mattockae0e47f2011-03-01 15:06:02 +0100780 * inotify_user_setup - Our initialization function. Note that we cannot return
Amy Griffis2d9048e2006-06-01 13:10:59 -0700781 * error because we have compiled-in VFS hooks. So an (unlikely) failure here
782 * must result in panic().
783 */
784static int __init inotify_user_setup(void)
785{
Eric Parisf874e1a2010-07-28 10:18:37 -0400786 BUILD_BUG_ON(IN_ACCESS != FS_ACCESS);
787 BUILD_BUG_ON(IN_MODIFY != FS_MODIFY);
788 BUILD_BUG_ON(IN_ATTRIB != FS_ATTRIB);
789 BUILD_BUG_ON(IN_CLOSE_WRITE != FS_CLOSE_WRITE);
790 BUILD_BUG_ON(IN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
791 BUILD_BUG_ON(IN_OPEN != FS_OPEN);
792 BUILD_BUG_ON(IN_MOVED_FROM != FS_MOVED_FROM);
793 BUILD_BUG_ON(IN_MOVED_TO != FS_MOVED_TO);
794 BUILD_BUG_ON(IN_CREATE != FS_CREATE);
795 BUILD_BUG_ON(IN_DELETE != FS_DELETE);
796 BUILD_BUG_ON(IN_DELETE_SELF != FS_DELETE_SELF);
797 BUILD_BUG_ON(IN_MOVE_SELF != FS_MOVE_SELF);
798 BUILD_BUG_ON(IN_UNMOUNT != FS_UNMOUNT);
799 BUILD_BUG_ON(IN_Q_OVERFLOW != FS_Q_OVERFLOW);
800 BUILD_BUG_ON(IN_IGNORED != FS_IN_IGNORED);
801 BUILD_BUG_ON(IN_EXCL_UNLINK != FS_EXCL_UNLINK);
Eric Parisb29866a2010-10-28 17:21:58 -0400802 BUILD_BUG_ON(IN_ISDIR != FS_ISDIR);
Eric Parisf874e1a2010-07-28 10:18:37 -0400803 BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT);
804
805 BUG_ON(hweight32(ALL_INOTIFY_BITS) != 21);
806
Eric Paris000285d2009-12-17 21:24:24 -0500807 inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark, SLAB_PANIC);
Eric Paris63c882a2009-05-21 17:02:01 -0400808
Amy Griffis2d9048e2006-06-01 13:10:59 -0700809 inotify_max_queued_events = 16384;
810 inotify_max_user_instances = 128;
811 inotify_max_user_watches = 8192;
812
Amy Griffis2d9048e2006-06-01 13:10:59 -0700813 return 0;
814}
Amy Griffis2d9048e2006-06-01 13:10:59 -0700815module_init(inotify_user_setup);