Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 1 | /* |
| 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 | * |
| 11 | * Copyright (C) 2009 Eric Paris <Red Hat Inc> |
| 12 | * inotify was largely rewriten to make use of the fsnotify infrastructure |
| 13 | * |
| 14 | * 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 | |
Eric Paris | 8c1934c | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 25 | #include <linux/dcache.h> /* d_unlinked */ |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 26 | #include <linux/fs.h> /* struct inode */ |
| 27 | #include <linux/fsnotify_backend.h> |
| 28 | #include <linux/inotify.h> |
| 29 | #include <linux/path.h> /* struct path */ |
| 30 | #include <linux/slab.h> /* kmem_* */ |
| 31 | #include <linux/types.h> |
Pavel Emelyanov | b3b38d8 | 2010-05-12 15:34:07 -0700 | [diff] [blame] | 32 | #include <linux/sched.h> |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 33 | |
| 34 | #include "inotify.h" |
| 35 | |
Eric Paris | 74766bb | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 36 | /* |
| 37 | * Check if 2 events contain the same information. We do not compare private data |
| 38 | * but at this moment that isn't a problem for any know fsnotify listeners. |
| 39 | */ |
| 40 | static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new) |
| 41 | { |
| 42 | if ((old->mask == new->mask) && |
| 43 | (old->to_tell == new->to_tell) && |
| 44 | (old->data_type == new->data_type) && |
| 45 | (old->name_len == new->name_len)) { |
| 46 | switch (old->data_type) { |
| 47 | case (FSNOTIFY_EVENT_INODE): |
| 48 | /* remember, after old was put on the wait_q we aren't |
| 49 | * allowed to look at the inode any more, only thing |
| 50 | * left to check was if the file_name is the same */ |
| 51 | if (!old->name_len || |
| 52 | !strcmp(old->file_name, new->file_name)) |
| 53 | return true; |
| 54 | break; |
Eric Paris | 3bcf386 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 55 | case (FSNOTIFY_EVENT_FILE): |
| 56 | if ((old->file->f_path.mnt == new->file->f_path.mnt) && |
| 57 | (old->file->f_path.dentry == new->file->f_path.dentry)) |
Eric Paris | 74766bb | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 58 | return true; |
| 59 | break; |
| 60 | case (FSNOTIFY_EVENT_NONE): |
| 61 | if (old->mask & FS_Q_OVERFLOW) |
| 62 | return true; |
| 63 | else if (old->mask & FS_IN_IGNORED) |
| 64 | return false; |
| 65 | return true; |
| 66 | }; |
| 67 | } |
| 68 | return false; |
| 69 | } |
| 70 | |
Eric Paris | f70ab54 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 71 | static struct fsnotify_event *inotify_merge(struct list_head *list, |
| 72 | struct fsnotify_event *event) |
Eric Paris | 74766bb | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 73 | { |
| 74 | struct fsnotify_event_holder *last_holder; |
| 75 | struct fsnotify_event *last_event; |
Eric Paris | 74766bb | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 76 | |
| 77 | /* and the list better be locked by something too */ |
| 78 | spin_lock(&event->lock); |
| 79 | |
| 80 | last_holder = list_entry(list->prev, struct fsnotify_event_holder, event_list); |
| 81 | last_event = last_holder->event; |
| 82 | if (event_compare(last_event, event)) |
Eric Paris | f70ab54 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 83 | fsnotify_get_event(last_event); |
| 84 | else |
| 85 | last_event = NULL; |
Eric Paris | 74766bb | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 86 | |
| 87 | spin_unlock(&event->lock); |
| 88 | |
Eric Paris | f70ab54 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 89 | return last_event; |
Eric Paris | 74766bb | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 90 | } |
| 91 | |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame^] | 92 | static int inotify_handle_event(struct fsnotify_group *group, |
| 93 | struct fsnotify_mark *mark, |
| 94 | struct fsnotify_event *event) |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 95 | { |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 96 | struct fsnotify_mark *fsn_mark; |
| 97 | struct inotify_inode_mark *i_mark; |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 98 | struct inode *to_tell; |
| 99 | struct inotify_event_private_data *event_priv; |
| 100 | struct fsnotify_event_private_data *fsn_event_priv; |
Eric Paris | f70ab54 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 101 | struct fsnotify_event *added_event; |
| 102 | int wd, ret = 0; |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 103 | |
Eric Paris | 5ba08e2 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 104 | pr_debug("%s: group=%p event=%p to_tell=%p mask=%x\n", __func__, group, |
| 105 | event, event->to_tell, event->mask); |
| 106 | |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 107 | to_tell = event->to_tell; |
| 108 | |
Eric Paris | 5444e29 | 2009-12-17 21:24:27 -0500 | [diff] [blame] | 109 | fsn_mark = fsnotify_find_inode_mark(group, to_tell); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 110 | /* race with watch removal? We already passes should_send */ |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 111 | if (unlikely(!fsn_mark)) |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 112 | return 0; |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 113 | i_mark = container_of(fsn_mark, struct inotify_inode_mark, |
| 114 | fsn_mark); |
| 115 | wd = i_mark->wd; |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 116 | |
| 117 | event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL); |
| 118 | if (unlikely(!event_priv)) |
| 119 | return -ENOMEM; |
| 120 | |
| 121 | fsn_event_priv = &event_priv->fsnotify_event_priv_data; |
| 122 | |
| 123 | fsn_event_priv->group = group; |
| 124 | event_priv->wd = wd; |
| 125 | |
Eric Paris | f70ab54 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 126 | added_event = fsnotify_add_notify_event(group, event, fsn_event_priv, inotify_merge); |
| 127 | if (added_event) { |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 128 | inotify_free_event_priv(fsn_event_priv); |
Eric Paris | f70ab54 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 129 | if (!IS_ERR(added_event)) |
| 130 | fsnotify_put_event(added_event); |
| 131 | else |
| 132 | ret = PTR_ERR(added_event); |
Eric Paris | eef3a11 | 2009-08-16 21:51:44 -0400 | [diff] [blame] | 133 | } |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 134 | |
Eric Paris | ff31100 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 135 | if (fsn_mark->mask & IN_ONESHOT) |
| 136 | fsnotify_destroy_mark(fsn_mark); |
| 137 | |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 138 | /* |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 139 | * If we hold the fsn_mark until after the event is on the queue |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 140 | * IN_IGNORED won't be able to pass this event in the queue |
| 141 | */ |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 142 | fsnotify_put_mark(fsn_mark); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 143 | |
| 144 | return ret; |
| 145 | } |
| 146 | |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 147 | static void inotify_freeing_mark(struct fsnotify_mark *fsn_mark, struct fsnotify_group *group) |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 148 | { |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 149 | inotify_ignored_and_remove_idr(fsn_mark, group); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 150 | } |
| 151 | |
Eric Paris | 7b0a04f | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 152 | static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame^] | 153 | struct vfsmount *mnt, struct fsnotify_mark *mark, |
| 154 | __u32 mask, void *data, int data_type) |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 155 | { |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 156 | struct fsnotify_mark *fsn_mark; |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 157 | bool send; |
| 158 | |
Eric Paris | 5ba08e2 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 159 | pr_debug("%s: group=%p inode=%p mask=%x data=%p data_type=%d\n", |
| 160 | __func__, group, inode, mask, data, data_type); |
| 161 | |
Eric Paris | 5444e29 | 2009-12-17 21:24:27 -0500 | [diff] [blame] | 162 | fsn_mark = fsnotify_find_inode_mark(group, inode); |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 163 | if (!fsn_mark) |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 164 | return false; |
| 165 | |
Eric Paris | e42e277 | 2009-06-11 11:09:47 -0400 | [diff] [blame] | 166 | mask = (mask & ~FS_EVENT_ON_CHILD); |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 167 | send = (fsn_mark->mask & mask); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 168 | |
Eric Paris | 8c1934c | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 169 | if (send && (fsn_mark->mask & FS_EXCL_UNLINK) && |
Eric Paris | 3bcf386 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 170 | (data_type == FSNOTIFY_EVENT_FILE)) { |
| 171 | struct file *file = data; |
Eric Paris | 8c1934c | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 172 | |
Eric Paris | 3bcf386 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 173 | if (d_unlinked(file->f_path.dentry)) |
Eric Paris | 8c1934c | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 174 | send = false; |
| 175 | } |
| 176 | |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 177 | /* find took a reference */ |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 178 | fsnotify_put_mark(fsn_mark); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 179 | |
| 180 | return send; |
| 181 | } |
| 182 | |
Eric Paris | cf43742 | 2009-08-24 16:03:35 -0400 | [diff] [blame] | 183 | /* |
| 184 | * This is NEVER supposed to be called. Inotify marks should either have been |
| 185 | * removed from the idr when the watch was removed or in the |
| 186 | * fsnotify_destroy_mark_by_group() call when the inotify instance was being |
| 187 | * torn down. This is only called if the idr is about to be freed but there |
| 188 | * are still marks in it. |
| 189 | */ |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 190 | static int idr_callback(int id, void *p, void *data) |
| 191 | { |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 192 | struct fsnotify_mark *fsn_mark; |
| 193 | struct inotify_inode_mark *i_mark; |
Eric Paris | cf43742 | 2009-08-24 16:03:35 -0400 | [diff] [blame] | 194 | static bool warned = false; |
| 195 | |
| 196 | if (warned) |
| 197 | return 0; |
| 198 | |
Eric Paris | 976ae32 | 2010-01-15 12:12:25 -0500 | [diff] [blame] | 199 | warned = true; |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 200 | fsn_mark = p; |
| 201 | i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark); |
Eric Paris | cf43742 | 2009-08-24 16:03:35 -0400 | [diff] [blame] | 202 | |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 203 | WARN(1, "inotify closing but id=%d for fsn_mark=%p in group=%p still in " |
Eric Paris | cf43742 | 2009-08-24 16:03:35 -0400 | [diff] [blame] | 204 | "idr. Probably leaking memory\n", id, p, data); |
| 205 | |
| 206 | /* |
| 207 | * I'm taking the liberty of assuming that the mark in question is a |
| 208 | * valid address and I'm dereferencing it. This might help to figure |
| 209 | * out why we got here and the panic is no worse than the original |
| 210 | * BUG() that was here. |
| 211 | */ |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 212 | if (fsn_mark) |
| 213 | printk(KERN_WARNING "fsn_mark->group=%p inode=%p wd=%d\n", |
| 214 | fsn_mark->group, fsn_mark->i.inode, i_mark->wd); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 215 | return 0; |
| 216 | } |
| 217 | |
| 218 | static void inotify_free_group_priv(struct fsnotify_group *group) |
| 219 | { |
| 220 | /* ideally the idr is empty and we won't hit the BUG in teh callback */ |
Eric Paris | cf43742 | 2009-08-24 16:03:35 -0400 | [diff] [blame] | 221 | idr_for_each(&group->inotify_data.idr, idr_callback, group); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 222 | idr_remove_all(&group->inotify_data.idr); |
| 223 | idr_destroy(&group->inotify_data.idr); |
Pavel Emelyanov | b3b38d8 | 2010-05-12 15:34:07 -0700 | [diff] [blame] | 224 | free_uid(group->inotify_data.user); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 225 | } |
| 226 | |
| 227 | void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv) |
| 228 | { |
| 229 | struct inotify_event_private_data *event_priv; |
| 230 | |
| 231 | |
| 232 | event_priv = container_of(fsn_event_priv, struct inotify_event_private_data, |
| 233 | fsnotify_event_priv_data); |
| 234 | |
| 235 | kmem_cache_free(event_priv_cachep, event_priv); |
| 236 | } |
| 237 | |
| 238 | const struct fsnotify_ops inotify_fsnotify_ops = { |
| 239 | .handle_event = inotify_handle_event, |
| 240 | .should_send_event = inotify_should_send_event, |
| 241 | .free_group_priv = inotify_free_group_priv, |
| 242 | .free_event_priv = inotify_free_event_priv, |
| 243 | .freeing_mark = inotify_freeing_mark, |
| 244 | }; |