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; |
Linus Torvalds | 2069601 | 2010-08-12 14:23:04 -0700 | [diff] [blame] | 55 | case (FSNOTIFY_EVENT_PATH): |
| 56 | if ((old->path.mnt == new->path.mnt) && |
| 57 | (old->path.dentry == new->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, |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 93 | struct fsnotify_mark *inode_mark, |
| 94 | struct fsnotify_mark *vfsmount_mark, |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 95 | struct fsnotify_event *event) |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 96 | { |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 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 | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 104 | BUG_ON(vfsmount_mark); |
| 105 | |
Eric Paris | 5ba08e2 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 106 | pr_debug("%s: group=%p event=%p to_tell=%p mask=%x\n", __func__, group, |
| 107 | event, event->to_tell, event->mask); |
| 108 | |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 109 | to_tell = event->to_tell; |
| 110 | |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 111 | i_mark = container_of(inode_mark, struct inotify_inode_mark, |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 112 | fsn_mark); |
| 113 | wd = i_mark->wd; |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 114 | |
| 115 | event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL); |
| 116 | if (unlikely(!event_priv)) |
| 117 | return -ENOMEM; |
| 118 | |
| 119 | fsn_event_priv = &event_priv->fsnotify_event_priv_data; |
| 120 | |
| 121 | fsn_event_priv->group = group; |
| 122 | event_priv->wd = wd; |
| 123 | |
Eric Paris | f70ab54 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 124 | added_event = fsnotify_add_notify_event(group, event, fsn_event_priv, inotify_merge); |
| 125 | if (added_event) { |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 126 | inotify_free_event_priv(fsn_event_priv); |
Eric Paris | f70ab54 | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 127 | if (!IS_ERR(added_event)) |
| 128 | fsnotify_put_event(added_event); |
| 129 | else |
| 130 | ret = PTR_ERR(added_event); |
Eric Paris | eef3a11 | 2009-08-16 21:51:44 -0400 | [diff] [blame] | 131 | } |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 132 | |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 133 | if (inode_mark->mask & IN_ONESHOT) |
| 134 | fsnotify_destroy_mark(inode_mark); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 135 | |
| 136 | return ret; |
| 137 | } |
| 138 | |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 139 | 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] | 140 | { |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 141 | inotify_ignored_and_remove_idr(fsn_mark, group); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 142 | } |
| 143 | |
Eric Paris | 7b0a04f | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 144 | static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, |
Eric Paris | 1968f5e | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 145 | struct fsnotify_mark *inode_mark, |
Eric Paris | ce8f76f | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 146 | struct fsnotify_mark *vfsmount_mark, |
Eric Paris | 3a9b16b | 2010-07-28 10:18:38 -0400 | [diff] [blame] | 147 | __u32 mask, void *data, int data_type) |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 148 | { |
Eric Paris | 1968f5e | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 149 | if ((inode_mark->mask & FS_EXCL_UNLINK) && |
Linus Torvalds | 2069601 | 2010-08-12 14:23:04 -0700 | [diff] [blame] | 150 | (data_type == FSNOTIFY_EVENT_PATH)) { |
| 151 | struct path *path = data; |
Eric Paris | 8c1934c | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 152 | |
Linus Torvalds | 2069601 | 2010-08-12 14:23:04 -0700 | [diff] [blame] | 153 | if (d_unlinked(path->dentry)) |
Eric Paris | 2612abb | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 154 | return false; |
Eric Paris | 8c1934c | 2010-07-28 10:18:37 -0400 | [diff] [blame] | 155 | } |
| 156 | |
Eric Paris | 2612abb | 2010-07-28 10:18:39 -0400 | [diff] [blame] | 157 | return true; |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 158 | } |
| 159 | |
Eric Paris | cf43742 | 2009-08-24 16:03:35 -0400 | [diff] [blame] | 160 | /* |
| 161 | * This is NEVER supposed to be called. Inotify marks should either have been |
| 162 | * removed from the idr when the watch was removed or in the |
| 163 | * fsnotify_destroy_mark_by_group() call when the inotify instance was being |
| 164 | * torn down. This is only called if the idr is about to be freed but there |
| 165 | * are still marks in it. |
| 166 | */ |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 167 | static int idr_callback(int id, void *p, void *data) |
| 168 | { |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 169 | struct fsnotify_mark *fsn_mark; |
| 170 | struct inotify_inode_mark *i_mark; |
Eric Paris | cf43742 | 2009-08-24 16:03:35 -0400 | [diff] [blame] | 171 | static bool warned = false; |
| 172 | |
| 173 | if (warned) |
| 174 | return 0; |
| 175 | |
Eric Paris | 976ae32 | 2010-01-15 12:12:25 -0500 | [diff] [blame] | 176 | warned = true; |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 177 | fsn_mark = p; |
| 178 | i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark); |
Eric Paris | cf43742 | 2009-08-24 16:03:35 -0400 | [diff] [blame] | 179 | |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 180 | 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] | 181 | "idr. Probably leaking memory\n", id, p, data); |
| 182 | |
| 183 | /* |
| 184 | * I'm taking the liberty of assuming that the mark in question is a |
| 185 | * valid address and I'm dereferencing it. This might help to figure |
| 186 | * out why we got here and the panic is no worse than the original |
| 187 | * BUG() that was here. |
| 188 | */ |
Eric Paris | 000285d | 2009-12-17 21:24:24 -0500 | [diff] [blame] | 189 | if (fsn_mark) |
| 190 | printk(KERN_WARNING "fsn_mark->group=%p inode=%p wd=%d\n", |
| 191 | fsn_mark->group, fsn_mark->i.inode, i_mark->wd); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 192 | return 0; |
| 193 | } |
| 194 | |
| 195 | static void inotify_free_group_priv(struct fsnotify_group *group) |
| 196 | { |
| 197 | /* 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] | 198 | idr_for_each(&group->inotify_data.idr, idr_callback, group); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 199 | idr_remove_all(&group->inotify_data.idr); |
| 200 | idr_destroy(&group->inotify_data.idr); |
Eric Paris | d0de4dc | 2011-04-05 17:20:50 -0400 | [diff] [blame^] | 201 | atomic_dec(&group->inotify_data.user->inotify_devs); |
Pavel Emelyanov | b3b38d8 | 2010-05-12 15:34:07 -0700 | [diff] [blame] | 202 | free_uid(group->inotify_data.user); |
Eric Paris | 63c882a | 2009-05-21 17:02:01 -0400 | [diff] [blame] | 203 | } |
| 204 | |
| 205 | void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv) |
| 206 | { |
| 207 | struct inotify_event_private_data *event_priv; |
| 208 | |
| 209 | |
| 210 | event_priv = container_of(fsn_event_priv, struct inotify_event_private_data, |
| 211 | fsnotify_event_priv_data); |
| 212 | |
| 213 | kmem_cache_free(event_priv_cachep, event_priv); |
| 214 | } |
| 215 | |
| 216 | const struct fsnotify_ops inotify_fsnotify_ops = { |
| 217 | .handle_event = inotify_handle_event, |
| 218 | .should_send_event = inotify_should_send_event, |
| 219 | .free_group_priv = inotify_free_group_priv, |
| 220 | .free_event_priv = inotify_free_event_priv, |
| 221 | .freeing_mark = inotify_freeing_mark, |
| 222 | }; |