diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-11 17:22:55 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-11 17:22:55 -0400 |
commit | 3bb66d7f8cc31537a3170c9bb82b38e538b984c5 (patch) | |
tree | e7174a8e9b805e056c3b0e510789a611ce4eeb1c | |
parent | 512626a04e72aca60effe111fa0333ed0b195d21 (diff) | |
parent | a092ee20fd33d2df0990dcbf2235afc181612818 (diff) |
Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify
* 'for-linus' of git://git.infradead.org/users/eparis/notify:
fsnotify: allow groups to set freeing_mark to null
inotify/dnotify: should_send_event shouldn't match on FS_EVENT_ON_CHILD
dnotify: do not bother to lock entry->lock when reading mask
dnotify: do not use ?true:false when assigning to a bool
fsnotify: move events should indicate the event was on a child
inotify: reimplement inotify using fsnotify
fsnotify: handle filesystem unmounts with fsnotify marks
fsnotify: fsnotify marks on inodes pin them in core
fsnotify: allow groups to add private data to events
fsnotify: add correlations between events
fsnotify: include pathnames with entries when possible
fsnotify: generic notification queue and waitq
dnotify: reimplement dnotify using fsnotify
fsnotify: parent event notification
fsnotify: add marks to inodes so groups can interpret how to handle those inodes
fsnotify: unified filesystem notification backend
-rw-r--r-- | MAINTAINERS | 8 | ||||
-rw-r--r-- | fs/inode.c | 10 | ||||
-rw-r--r-- | fs/notify/Kconfig | 13 | ||||
-rw-r--r-- | fs/notify/Makefile | 2 | ||||
-rw-r--r-- | fs/notify/dnotify/Kconfig | 1 | ||||
-rw-r--r-- | fs/notify/dnotify/dnotify.c | 464 | ||||
-rw-r--r-- | fs/notify/fsnotify.c | 186 | ||||
-rw-r--r-- | fs/notify/fsnotify.h | 34 | ||||
-rw-r--r-- | fs/notify/group.c | 254 | ||||
-rw-r--r-- | fs/notify/inode_mark.c | 426 | ||||
-rw-r--r-- | fs/notify/inotify/Kconfig | 20 | ||||
-rw-r--r-- | fs/notify/inotify/Makefile | 2 | ||||
-rw-r--r-- | fs/notify/inotify/inotify.c | 20 | ||||
-rw-r--r-- | fs/notify/inotify/inotify.h | 21 | ||||
-rw-r--r-- | fs/notify/inotify/inotify_fsnotify.c | 138 | ||||
-rw-r--r-- | fs/notify/inotify/inotify_user.c | 837 | ||||
-rw-r--r-- | fs/notify/notification.c | 411 | ||||
-rw-r--r-- | include/linux/dcache.h | 4 | ||||
-rw-r--r-- | include/linux/dnotify.h | 29 | ||||
-rw-r--r-- | include/linux/fs.h | 6 | ||||
-rw-r--r-- | include/linux/fsnotify.h | 199 | ||||
-rw-r--r-- | include/linux/fsnotify_backend.h | 387 | ||||
-rw-r--r-- | init/Kconfig | 3 |
23 files changed, 2813 insertions, 662 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 1a0084e22cf3..c944d618dc83 100644 --- a/MAINTAINERS +++ b/MAINTAINERS | |||
@@ -1802,10 +1802,10 @@ F: drivers/char/epca* | |||
1802 | F: drivers/char/digi* | 1802 | F: drivers/char/digi* |
1803 | 1803 | ||
1804 | DIRECTORY NOTIFICATION (DNOTIFY) | 1804 | DIRECTORY NOTIFICATION (DNOTIFY) |
1805 | P: Stephen Rothwell | 1805 | P: Eric Paris |
1806 | M: sfr@canb.auug.org.au | 1806 | M: eparis@parisplace.org |
1807 | L: linux-kernel@vger.kernel.org | 1807 | L: linux-kernel@vger.kernel.org |
1808 | S: Supported | 1808 | S: Maintained |
1809 | F: Documentation/filesystems/dnotify.txt | 1809 | F: Documentation/filesystems/dnotify.txt |
1810 | F: fs/notify/dnotify/ | 1810 | F: fs/notify/dnotify/ |
1811 | F: include/linux/dnotify.h | 1811 | F: include/linux/dnotify.h |
@@ -2858,6 +2858,8 @@ P: John McCutchan | |||
2858 | M: john@johnmccutchan.com | 2858 | M: john@johnmccutchan.com |
2859 | P: Robert Love | 2859 | P: Robert Love |
2860 | M: rlove@rlove.org | 2860 | M: rlove@rlove.org |
2861 | P: Eric Paris | ||
2862 | M: eparis@parisplace.org | ||
2861 | L: linux-kernel@vger.kernel.org | 2863 | L: linux-kernel@vger.kernel.org |
2862 | S: Maintained | 2864 | S: Maintained |
2863 | F: Documentation/filesystems/inotify.txt | 2865 | F: Documentation/filesystems/inotify.txt |
diff --git a/fs/inode.c b/fs/inode.c index bca0c618fdb3..ca337014ae29 100644 --- a/fs/inode.c +++ b/fs/inode.c | |||
@@ -22,6 +22,7 @@ | |||
22 | #include <linux/cdev.h> | 22 | #include <linux/cdev.h> |
23 | #include <linux/bootmem.h> | 23 | #include <linux/bootmem.h> |
24 | #include <linux/inotify.h> | 24 | #include <linux/inotify.h> |
25 | #include <linux/fsnotify.h> | ||
25 | #include <linux/mount.h> | 26 | #include <linux/mount.h> |
26 | #include <linux/async.h> | 27 | #include <linux/async.h> |
27 | 28 | ||
@@ -189,6 +190,10 @@ struct inode *inode_init_always(struct super_block *sb, struct inode *inode) | |||
189 | inode->i_private = NULL; | 190 | inode->i_private = NULL; |
190 | inode->i_mapping = mapping; | 191 | inode->i_mapping = mapping; |
191 | 192 | ||
193 | #ifdef CONFIG_FSNOTIFY | ||
194 | inode->i_fsnotify_mask = 0; | ||
195 | #endif | ||
196 | |||
192 | return inode; | 197 | return inode; |
193 | 198 | ||
194 | out_free_security: | 199 | out_free_security: |
@@ -221,6 +226,7 @@ void destroy_inode(struct inode *inode) | |||
221 | BUG_ON(inode_has_buffers(inode)); | 226 | BUG_ON(inode_has_buffers(inode)); |
222 | ima_inode_free(inode); | 227 | ima_inode_free(inode); |
223 | security_inode_free(inode); | 228 | security_inode_free(inode); |
229 | fsnotify_inode_delete(inode); | ||
224 | if (inode->i_sb->s_op->destroy_inode) | 230 | if (inode->i_sb->s_op->destroy_inode) |
225 | inode->i_sb->s_op->destroy_inode(inode); | 231 | inode->i_sb->s_op->destroy_inode(inode); |
226 | else | 232 | else |
@@ -252,6 +258,9 @@ void inode_init_once(struct inode *inode) | |||
252 | INIT_LIST_HEAD(&inode->inotify_watches); | 258 | INIT_LIST_HEAD(&inode->inotify_watches); |
253 | mutex_init(&inode->inotify_mutex); | 259 | mutex_init(&inode->inotify_mutex); |
254 | #endif | 260 | #endif |
261 | #ifdef CONFIG_FSNOTIFY | ||
262 | INIT_HLIST_HEAD(&inode->i_fsnotify_mark_entries); | ||
263 | #endif | ||
255 | } | 264 | } |
256 | EXPORT_SYMBOL(inode_init_once); | 265 | EXPORT_SYMBOL(inode_init_once); |
257 | 266 | ||
@@ -398,6 +407,7 @@ int invalidate_inodes(struct super_block *sb) | |||
398 | mutex_lock(&iprune_mutex); | 407 | mutex_lock(&iprune_mutex); |
399 | spin_lock(&inode_lock); | 408 | spin_lock(&inode_lock); |
400 | inotify_unmount_inodes(&sb->s_inodes); | 409 | inotify_unmount_inodes(&sb->s_inodes); |
410 | fsnotify_unmount_inodes(&sb->s_inodes); | ||
401 | busy = invalidate_list(&sb->s_inodes, &throw_away); | 411 | busy = invalidate_list(&sb->s_inodes, &throw_away); |
402 | spin_unlock(&inode_lock); | 412 | spin_unlock(&inode_lock); |
403 | 413 | ||
diff --git a/fs/notify/Kconfig b/fs/notify/Kconfig index 50914d7303c6..31dac7e3b0f1 100644 --- a/fs/notify/Kconfig +++ b/fs/notify/Kconfig | |||
@@ -1,2 +1,15 @@ | |||
1 | config FSNOTIFY | ||
2 | bool "Filesystem notification backend" | ||
3 | default y | ||
4 | ---help--- | ||
5 | fsnotify is a backend for filesystem notification. fsnotify does | ||
6 | not provide any userspace interface but does provide the basis | ||
7 | needed for other notification schemes such as dnotify, inotify, | ||
8 | and fanotify. | ||
9 | |||
10 | Say Y here to enable fsnotify suport. | ||
11 | |||
12 | If unsure, say Y. | ||
13 | |||
1 | source "fs/notify/dnotify/Kconfig" | 14 | source "fs/notify/dnotify/Kconfig" |
2 | source "fs/notify/inotify/Kconfig" | 15 | source "fs/notify/inotify/Kconfig" |
diff --git a/fs/notify/Makefile b/fs/notify/Makefile index 5a95b6010ce7..0922cc826c46 100644 --- a/fs/notify/Makefile +++ b/fs/notify/Makefile | |||
@@ -1,2 +1,4 @@ | |||
1 | obj-$(CONFIG_FSNOTIFY) += fsnotify.o notification.o group.o inode_mark.o | ||
2 | |||
1 | obj-y += dnotify/ | 3 | obj-y += dnotify/ |
2 | obj-y += inotify/ | 4 | obj-y += inotify/ |
diff --git a/fs/notify/dnotify/Kconfig b/fs/notify/dnotify/Kconfig index 26adf5dfa646..904ff8d5405a 100644 --- a/fs/notify/dnotify/Kconfig +++ b/fs/notify/dnotify/Kconfig | |||
@@ -1,5 +1,6 @@ | |||
1 | config DNOTIFY | 1 | config DNOTIFY |
2 | bool "Dnotify support" | 2 | bool "Dnotify support" |
3 | depends on FSNOTIFY | ||
3 | default y | 4 | default y |
4 | help | 5 | help |
5 | Dnotify is a directory-based per-fd file change notification system | 6 | Dnotify is a directory-based per-fd file change notification system |
diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index b0aa2cde80bd..828a889be909 100644 --- a/fs/notify/dnotify/dnotify.c +++ b/fs/notify/dnotify/dnotify.c | |||
@@ -3,6 +3,9 @@ | |||
3 | * | 3 | * |
4 | * Copyright (C) 2000,2001,2002 Stephen Rothwell | 4 | * Copyright (C) 2000,2001,2002 Stephen Rothwell |
5 | * | 5 | * |
6 | * Copyright (C) 2009 Eric Paris <Red Hat Inc> | ||
7 | * dnotify was largly rewritten to use the new fsnotify infrastructure | ||
8 | * | ||
6 | * This program is free software; you can redistribute it and/or modify it | 9 | * This program is free software; you can redistribute it and/or modify it |
7 | * under the terms of the GNU General Public License as published by the | 10 | * under the terms of the GNU General Public License as published by the |
8 | * Free Software Foundation; either version 2, or (at your option) any | 11 | * Free Software Foundation; either version 2, or (at your option) any |
@@ -21,24 +24,173 @@ | |||
21 | #include <linux/spinlock.h> | 24 | #include <linux/spinlock.h> |
22 | #include <linux/slab.h> | 25 | #include <linux/slab.h> |
23 | #include <linux/fdtable.h> | 26 | #include <linux/fdtable.h> |
27 | #include <linux/fsnotify_backend.h> | ||
24 | 28 | ||
25 | int dir_notify_enable __read_mostly = 1; | 29 | int dir_notify_enable __read_mostly = 1; |
26 | 30 | ||
27 | static struct kmem_cache *dn_cache __read_mostly; | 31 | static struct kmem_cache *dnotify_struct_cache __read_mostly; |
32 | static struct kmem_cache *dnotify_mark_entry_cache __read_mostly; | ||
33 | static struct fsnotify_group *dnotify_group __read_mostly; | ||
34 | static DEFINE_MUTEX(dnotify_mark_mutex); | ||
35 | |||
36 | /* | ||
37 | * dnotify will attach one of these to each inode (i_fsnotify_mark_entries) which | ||
38 | * is being watched by dnotify. If multiple userspace applications are watching | ||
39 | * the same directory with dnotify their information is chained in dn | ||
40 | */ | ||
41 | struct dnotify_mark_entry { | ||
42 | struct fsnotify_mark_entry fsn_entry; | ||
43 | struct dnotify_struct *dn; | ||
44 | }; | ||
28 | 45 | ||
29 | static void redo_inode_mask(struct inode *inode) | 46 | /* |
47 | * When a process starts or stops watching an inode the set of events which | ||
48 | * dnotify cares about for that inode may change. This function runs the | ||
49 | * list of everything receiving dnotify events about this directory and calculates | ||
50 | * the set of all those events. After it updates what dnotify is interested in | ||
51 | * it calls the fsnotify function so it can update the set of all events relevant | ||
52 | * to this inode. | ||
53 | */ | ||
54 | static void dnotify_recalc_inode_mask(struct fsnotify_mark_entry *entry) | ||
30 | { | 55 | { |
31 | unsigned long new_mask; | 56 | __u32 new_mask, old_mask; |
32 | struct dnotify_struct *dn; | 57 | struct dnotify_struct *dn; |
58 | struct dnotify_mark_entry *dnentry = container_of(entry, | ||
59 | struct dnotify_mark_entry, | ||
60 | fsn_entry); | ||
61 | |||
62 | assert_spin_locked(&entry->lock); | ||
33 | 63 | ||
64 | old_mask = entry->mask; | ||
34 | new_mask = 0; | 65 | new_mask = 0; |
35 | for (dn = inode->i_dnotify; dn != NULL; dn = dn->dn_next) | 66 | for (dn = dnentry->dn; dn != NULL; dn = dn->dn_next) |
36 | new_mask |= dn->dn_mask & ~DN_MULTISHOT; | 67 | new_mask |= (dn->dn_mask & ~FS_DN_MULTISHOT); |
37 | inode->i_dnotify_mask = new_mask; | 68 | entry->mask = new_mask; |
69 | |||
70 | if (old_mask == new_mask) | ||
71 | return; | ||
72 | |||
73 | if (entry->inode) | ||
74 | fsnotify_recalc_inode_mask(entry->inode); | ||
75 | } | ||
76 | |||
77 | /* | ||
78 | * Mains fsnotify call where events are delivered to dnotify. | ||
79 | * Find the dnotify mark on the relevant inode, run the list of dnotify structs | ||
80 | * on that mark and determine which of them has expressed interest in receiving | ||
81 | * events of this type. When found send the correct process and signal and | ||
82 | * destroy the dnotify struct if it was not registered to receive multiple | ||
83 | * events. | ||
84 | */ | ||
85 | static int dnotify_handle_event(struct fsnotify_group *group, | ||
86 | struct fsnotify_event *event) | ||
87 | { | ||
88 | struct fsnotify_mark_entry *entry = NULL; | ||
89 | struct dnotify_mark_entry *dnentry; | ||
90 | struct inode *to_tell; | ||
91 | struct dnotify_struct *dn; | ||
92 | struct dnotify_struct **prev; | ||
93 | struct fown_struct *fown; | ||
94 | |||
95 | to_tell = event->to_tell; | ||
96 | |||
97 | spin_lock(&to_tell->i_lock); | ||
98 | entry = fsnotify_find_mark_entry(group, to_tell); | ||
99 | spin_unlock(&to_tell->i_lock); | ||
100 | |||
101 | /* unlikely since we alreay passed dnotify_should_send_event() */ | ||
102 | if (unlikely(!entry)) | ||
103 | return 0; | ||
104 | dnentry = container_of(entry, struct dnotify_mark_entry, fsn_entry); | ||
105 | |||
106 | spin_lock(&entry->lock); | ||
107 | prev = &dnentry->dn; | ||
108 | while ((dn = *prev) != NULL) { | ||
109 | if ((dn->dn_mask & event->mask) == 0) { | ||
110 | prev = &dn->dn_next; | ||
111 | continue; | ||
112 | } | ||
113 | fown = &dn->dn_filp->f_owner; | ||
114 | send_sigio(fown, dn->dn_fd, POLL_MSG); | ||
115 | if (dn->dn_mask & FS_DN_MULTISHOT) | ||
116 | prev = &dn->dn_next; | ||
117 | else { | ||
118 | *prev = dn->dn_next; | ||
119 | kmem_cache_free(dnotify_struct_cache, dn); | ||
120 | dnotify_recalc_inode_mask(entry); | ||
121 | } | ||
122 | } | ||
123 | |||
124 | spin_unlock(&entry->lock); | ||
125 | fsnotify_put_mark(entry); | ||
126 | |||
127 | return 0; | ||
128 | } | ||
129 | |||
130 | /* | ||
131 | * Given an inode and mask determine if dnotify would be interested in sending | ||
132 | * userspace notification for that pair. | ||
133 | */ | ||
134 | static bool dnotify_should_send_event(struct fsnotify_group *group, | ||
135 | struct inode *inode, __u32 mask) | ||
136 | { | ||
137 | struct fsnotify_mark_entry *entry; | ||
138 | bool send; | ||
139 | |||
140 | /* !dir_notify_enable should never get here, don't waste time checking | ||
141 | if (!dir_notify_enable) | ||
142 | return 0; */ | ||
143 | |||
144 | /* not a dir, dnotify doesn't care */ | ||
145 | if (!S_ISDIR(inode->i_mode)) | ||
146 | return false; | ||
147 | |||
148 | spin_lock(&inode->i_lock); | ||
149 | entry = fsnotify_find_mark_entry(group, inode); | ||
150 | spin_unlock(&inode->i_lock); | ||
151 | |||
152 | /* no mark means no dnotify watch */ | ||
153 | if (!entry) | ||
154 | return false; | ||
155 | |||
156 | mask = (mask & ~FS_EVENT_ON_CHILD); | ||
157 | send = (mask & entry->mask); | ||
158 | |||
159 | fsnotify_put_mark(entry); /* matches fsnotify_find_mark_entry */ | ||
160 | |||
161 | return send; | ||
162 | } | ||
163 | |||
164 | static void dnotify_free_mark(struct fsnotify_mark_entry *entry) | ||
165 | { | ||
166 | struct dnotify_mark_entry *dnentry = container_of(entry, | ||
167 | struct dnotify_mark_entry, | ||
168 | fsn_entry); | ||
169 | |||
170 | BUG_ON(dnentry->dn); | ||
171 | |||
172 | kmem_cache_free(dnotify_mark_entry_cache, dnentry); | ||
38 | } | 173 | } |
39 | 174 | ||
175 | static struct fsnotify_ops dnotify_fsnotify_ops = { | ||
176 | .handle_event = dnotify_handle_event, | ||
177 | .should_send_event = dnotify_should_send_event, | ||
178 | .free_group_priv = NULL, | ||
179 | .freeing_mark = NULL, | ||
180 | .free_event_priv = NULL, | ||
181 | }; | ||
182 | |||
183 | /* | ||
184 | * Called every time a file is closed. Looks first for a dnotify mark on the | ||
185 | * inode. If one is found run all of the ->dn entries attached to that | ||
186 | * mark for one relevant to this process closing the file and remove that | ||
187 | * dnotify_struct. If that was the last dnotify_struct also remove the | ||
188 | * fsnotify_mark_entry. | ||
189 | */ | ||
40 | void dnotify_flush(struct file *filp, fl_owner_t id) | 190 | void dnotify_flush(struct file *filp, fl_owner_t id) |
41 | { | 191 | { |
192 | struct fsnotify_mark_entry *entry; | ||
193 | struct dnotify_mark_entry *dnentry; | ||
42 | struct dnotify_struct *dn; | 194 | struct dnotify_struct *dn; |
43 | struct dnotify_struct **prev; | 195 | struct dnotify_struct **prev; |
44 | struct inode *inode; | 196 | struct inode *inode; |
@@ -46,145 +198,243 @@ void dnotify_flush(struct file *filp, fl_owner_t id) | |||
46 | inode = filp->f_path.dentry->d_inode; | 198 | inode = filp->f_path.dentry->d_inode; |
47 | if (!S_ISDIR(inode->i_mode)) | 199 | if (!S_ISDIR(inode->i_mode)) |
48 | return; | 200 | return; |
201 | |||
49 | spin_lock(&inode->i_lock); | 202 | spin_lock(&inode->i_lock); |
50 | prev = &inode->i_dnotify; | 203 | entry = fsnotify_find_mark_entry(dnotify_group, inode); |
204 | spin_unlock(&inode->i_lock); | ||
205 | if (!entry) | ||
206 | return; | ||
207 | dnentry = container_of(entry, struct dnotify_mark_entry, fsn_entry); | ||
208 | |||
209 | mutex_lock(&dnotify_mark_mutex); | ||
210 | |||
211 | spin_lock(&entry->lock); | ||
212 | prev = &dnentry->dn; | ||
51 | while ((dn = *prev) != NULL) { | 213 | while ((dn = *prev) != NULL) { |
52 | if ((dn->dn_owner == id) && (dn->dn_filp == filp)) { | 214 | if ((dn->dn_owner == id) && (dn->dn_filp == filp)) { |
53 | *prev = dn->dn_next; | 215 | *prev = dn->dn_next; |
54 | redo_inode_mask(inode); | 216 | kmem_cache_free(dnotify_struct_cache, dn); |
55 | kmem_cache_free(dn_cache, dn); | 217 | dnotify_recalc_inode_mask(entry); |
56 | break; | 218 | break; |
57 | } | 219 | } |
58 | prev = &dn->dn_next; | 220 | prev = &dn->dn_next; |
59 | } | 221 | } |
60 | spin_unlock(&inode->i_lock); | 222 | |
223 | spin_unlock(&entry->lock); | ||
224 | |||
225 | /* nothing else could have found us thanks to the dnotify_mark_mutex */ | ||
226 | if (dnentry->dn == NULL) | ||
227 | fsnotify_destroy_mark_by_entry(entry); | ||
228 | |||
229 | fsnotify_recalc_group_mask(dnotify_group); | ||
230 | |||
231 | mutex_unlock(&dnotify_mark_mutex); | ||
232 | |||
233 | fsnotify_put_mark(entry); | ||
234 | } | ||
235 | |||
236 | /* this conversion is done only at watch creation */ | ||
237 | static __u32 convert_arg(unsigned long arg) | ||
238 | { | ||
239 | __u32 new_mask = FS_EVENT_ON_CHILD; | ||
240 | |||
241 | if (arg & DN_MULTISHOT) | ||
242 | new_mask |= FS_DN_MULTISHOT; | ||
243 | if (arg & DN_DELETE) | ||
244 | new_mask |= (FS_DELETE | FS_MOVED_FROM); | ||
245 | if (arg & DN_MODIFY) | ||
246 | new_mask |= FS_MODIFY; | ||
247 | if (arg & DN_ACCESS) | ||
248 | new_mask |= FS_ACCESS; | ||
249 | if (arg & DN_ATTRIB) | ||
250 | new_mask |= FS_ATTRIB; | ||
251 | if (arg & DN_RENAME) | ||
252 | new_mask |= FS_DN_RENAME; | ||
253 | if (arg & DN_CREATE) | ||
254 | new_mask |= (FS_CREATE | FS_MOVED_TO); | ||
255 | |||
256 | return new_mask; | ||
61 | } | 257 | } |
62 | 258 | ||
259 | /* | ||
260 | * If multiple processes watch the same inode with dnotify there is only one | ||
261 | * dnotify mark in inode->i_fsnotify_mark_entries but we chain a dnotify_struct | ||
262 | * onto that mark. This function either attaches the new dnotify_struct onto | ||
263 | * that list, or it |= the mask onto an existing dnofiy_struct. | ||
264 | */ | ||
265 | static int attach_dn(struct dnotify_struct *dn, struct dnotify_mark_entry *dnentry, | ||
266 | fl_owner_t id, int fd, struct file *filp, __u32 mask) | ||
267 | { | ||
268 | struct dnotify_struct *odn; | ||
269 | |||
270 | odn = dnentry->dn; | ||
271 | while (odn != NULL) { | ||
272 | /* adding more events to existing dnofiy_struct? */ | ||
273 | if ((odn->dn_owner == id) && (odn->dn_filp == filp)) { | ||
274 | odn->dn_fd = fd; | ||
275 | odn->dn_mask |= mask; | ||
276 | return -EEXIST; | ||
277 | } | ||
278 | odn = odn->dn_next; | ||
279 | } | ||
280 | |||
281 | dn->dn_mask = mask; | ||
282 | dn->dn_fd = fd; | ||
283 | dn->dn_filp = filp; | ||
284 | dn->dn_owner = id; | ||
285 | dn->dn_next = dnentry->dn; | ||
286 | dnentry->dn = dn; | ||
287 | |||
288 | return 0; | ||
289 | } | ||
290 | |||
291 | /* | ||
292 | * When a process calls fcntl to attach a dnotify watch to a directory it ends | ||
293 | * up here. Allocate both a mark for fsnotify to add and a dnotify_struct to be | ||
294 | * attached to the fsnotify_mark. | ||
295 | */ | ||
63 | int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) | 296 | int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) |
64 | { | 297 | { |
298 | struct dnotify_mark_entry *new_dnentry, *dnentry; | ||
299 | struct fsnotify_mark_entry *new_entry, *entry; | ||
65 | struct dnotify_struct *dn; | 300 | struct dnotify_struct *dn; |
66 | struct dnotify_struct *odn; | ||
67 | struct dnotify_struct **prev; | ||
68 | struct inode *inode; | 301 | struct inode *inode; |
69 | fl_owner_t id = current->files; | 302 | fl_owner_t id = current->files; |
70 | struct file *f; | 303 | struct file *f; |
71 | int error = 0; | 304 | int destroy = 0, error = 0; |
305 | __u32 mask; | ||
306 | |||
307 | /* we use these to tell if we need to kfree */ | ||
308 | new_entry = NULL; | ||
309 | dn = NULL; | ||
310 | |||
311 | if (!dir_notify_enable) { | ||
312 | error = -EINVAL; | ||
313 | goto out_err; | ||
314 | } | ||
72 | 315 | ||
316 | /* a 0 mask means we are explicitly removing the watch */ | ||
73 | if ((arg & ~DN_MULTISHOT) == 0) { | 317 | if ((arg & ~DN_MULTISHOT) == 0) { |
74 | dnotify_flush(filp, id); | 318 | dnotify_flush(filp, id); |
75 | return 0; | 319 | error = 0; |
320 | goto out_err; | ||
76 | } | 321 | } |
77 | if (!dir_notify_enable) | 322 | |
78 | return -EINVAL; | 323 | /* dnotify only works on directories */ |
79 | inode = filp->f_path.dentry->d_inode; | 324 | inode = filp->f_path.dentry->d_inode; |
80 | if (!S_ISDIR(inode->i_mode)) | 325 | if (!S_ISDIR(inode->i_mode)) { |
81 | return -ENOTDIR; | 326 | error = -ENOTDIR; |
82 | dn = kmem_cache_alloc(dn_cache, GFP_KERNEL); | 327 | goto out_err; |
83 | if (dn == NULL) | ||
84 | return -ENOMEM; | ||
85 | spin_lock(&inode->i_lock); | ||
86 | prev = &inode->i_dnotify; | ||
87 | while ((odn = *prev) != NULL) { | ||
88 | if ((odn->dn_owner == id) && (odn->dn_filp == filp)) { | ||
89 | odn->dn_fd = fd; | ||
90 | odn->dn_mask |= arg; | ||
91 | inode->i_dnotify_mask |= arg & ~DN_MULTISHOT; | ||
92 | goto out_free; | ||
93 | } | ||
94 | prev = &odn->dn_next; | ||
95 | } | 328 | } |
96 | 329 | ||
97 | rcu_read_lock(); | 330 | /* expect most fcntl to add new rather than augment old */ |
98 | f = fcheck(fd); | 331 | dn = kmem_cache_alloc(dnotify_struct_cache, GFP_KERNEL); |
99 | rcu_read_unlock(); | 332 | if (!dn) { |
100 | /* we'd lost the race with close(), sod off silently */ | 333 | error = -ENOMEM; |
101 | /* note that inode->i_lock prevents reordering problems | 334 | goto out_err; |
102 | * between accesses to descriptor table and ->i_dnotify */ | 335 | } |
103 | if (f != filp) | ||
104 | goto out_free; | ||
105 | 336 | ||
106 | error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0); | 337 | /* new fsnotify mark, we expect most fcntl calls to add a new mark */ |
107 | if (error) | 338 | new_dnentry = kmem_cache_alloc(dnotify_mark_entry_cache, GFP_KERNEL); |
108 | goto out_free; | 339 | if (!new_dnentry) { |
340 | error = -ENOMEM; | ||
341 | goto out_err; | ||
342 | } | ||
109 | 343 | ||
110 | dn->dn_mask = arg; | 344 | /* convert the userspace DN_* "arg" to the internal FS_* defines in fsnotify */ |
111 | dn->dn_fd = fd; | 345 | mask = convert_arg(arg); |
112 | dn->dn_filp = filp; | ||
113 | dn->dn_owner = id; | ||
114 | inode->i_dnotify_mask |= arg & ~DN_MULTISHOT; | ||
115 | dn->dn_next = inode->i_dnotify; | ||
116 | inode->i_dnotify = dn; | ||
117 | spin_unlock(&inode->i_lock); | ||
118 | return 0; | ||
119 | 346 | ||
120 | out_free: | 347 | /* set up the new_entry and new_dnentry */ |
121 | spin_unlock(&inode->i_lock); | 348 | new_entry = &new_dnentry->fsn_entry; |
122 | kmem_cache_free(dn_cache, dn); | 349 | fsnotify_init_mark(new_entry, dnotify_free_mark); |
123 | return error; | 350 | new_entry->mask = mask; |
124 | } | 351 | new_dnentry->dn = NULL; |
125 | 352 | ||
126 | void __inode_dir_notify(struct inode *inode, unsigned long event) | 353 | /* this is needed to prevent the fcntl/close race described below */ |
127 | { | 354 | mutex_lock(&dnotify_mark_mutex); |
128 | struct dnotify_struct * dn; | ||
129 | struct dnotify_struct **prev; | ||
130 | struct fown_struct * fown; | ||
131 | int changed = 0; | ||
132 | 355 | ||
356 | /* add the new_entry or find an old one. */ | ||
133 | spin_lock(&inode->i_lock); | 357 | spin_lock(&inode->i_lock); |
134 | prev = &inode->i_dnotify; | 358 | entry = fsnotify_find_mark_entry(dnotify_group, inode); |
135 | while ((dn = *prev) != NULL) { | ||
136 | if ((dn->dn_mask & event) == 0) { | ||
137 | prev = &dn->dn_next; | ||
138 | continue; | ||
139 | } | ||
140 | fown = &dn->dn_filp->f_owner; | ||
141 | send_sigio(fown, dn->dn_fd, POLL_MSG); | ||
142 | if (dn->dn_mask & DN_MULTISHOT) | ||
143 | prev = &dn->dn_next; | ||
144 | else { | ||
145 | *prev = dn->dn_next; | ||
146 | changed = 1; | ||
147 | kmem_cache_free(dn_cache, dn); | ||
148 | } | ||
149 | } | ||
150 | if (changed) | ||
151 | redo_inode_mask(inode); | ||
152 | spin_unlock(&inode->i_lock); | 359 | spin_unlock(&inode->i_lock); |
153 | } | 360 | if (entry) { |
154 | 361 | dnentry = container_of(entry, struct dnotify_mark_entry, fsn_entry); | |
155 | EXPORT_SYMBOL(__inode_dir_notify); | 362 | spin_lock(&entry->lock); |
363 | } else { | ||
364 | fsnotify_add_mark(new_entry, dnotify_group, inode); | ||
365 | spin_lock(&new_entry->lock); | ||
366 | entry = new_entry; | ||
367 | dnentry = new_dnentry; | ||
368 | /* we used new_entry, so don't free it */ | ||
369 | new_entry = NULL; | ||
370 | } | ||
156 | 371 | ||
157 | /* | 372 | rcu_read_lock(); |
158 | * This is hopelessly wrong, but unfixable without API changes. At | 373 | f = fcheck(fd); |
159 | * least it doesn't oops the kernel... | 374 | rcu_read_unlock(); |
160 | * | ||
161 | * To safely access ->d_parent we need to keep d_move away from it. Use the | ||
162 | * dentry's d_lock for this. | ||
163 | */ | ||
164 | void dnotify_parent(struct dentry *dentry, unsigned long event) | ||
165 | { | ||
166 | struct dentry *parent; | ||
167 | 375 | ||
168 | if (!dir_notify_enable) | 376 | /* if (f != filp) means that we lost a race and another task/thread |
169 | return; | 377 | * actually closed the fd we are still playing with before we grabbed |
378 | * the dnotify_mark_mutex and entry->lock. Since closing the fd is the | ||
379 | * only time we clean up the mark entries we need to get our mark off | ||
380 | * the list. */ | ||
381 | if (f != filp) { | ||
382 | /* if we added ourselves, shoot ourselves, it's possible that | ||
383 | * the flush actually did shoot this entry. That's fine too | ||
384 | * since multiple calls to destroy_mark is perfectly safe, if | ||
385 | * we found a dnentry already attached to the inode, just sod | ||
386 | * off silently as the flush at close time dealt with it. | ||
387 | */ | ||
388 | if (dnentry == new_dnentry) | ||
389 | destroy = 1; | ||
390 | goto out; | ||
391 | } | ||
170 | 392 | ||
171 | spin_lock(&dentry->d_lock); | 393 | error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0); |
172 | parent = dentry->d_parent; | 394 | if (error) { |
173 | if (parent->d_inode->i_dnotify_mask & event) { | 395 | /* if we added, we must shoot */ |
174 | dget(parent); | 396 | if (dnentry == new_dnentry) |
175 | spin_unlock(&dentry->d_lock); | 397 | destroy = 1; |
176 | __inode_dir_notify(parent->d_inode, event); | 398 | goto out; |
177 | dput(parent); | ||
178 | } else { | ||
179 | spin_unlock(&dentry->d_lock); | ||
180 | } | 399 | } |
400 | |||
401 | error = attach_dn(dn, dnentry, id, fd, filp, mask); | ||
402 | /* !error means that we attached the dn to the dnentry, so don't free it */ | ||
403 | if (!error) | ||
404 | dn = NULL; | ||
405 | /* -EEXIST means that we didn't add this new dn and used an old one. | ||
406 | * that isn't an error (and the unused dn should be freed) */ | ||
407 | else if (error == -EEXIST) | ||
408 | error = 0; | ||
409 | |||
410 | dnotify_recalc_inode_mask(entry); | ||
411 | out: | ||
412 | spin_unlock(&entry->lock); | ||
413 | |||
414 | if (destroy) | ||
415 | fsnotify_destroy_mark_by_entry(entry); | ||
416 | |||
417 | fsnotify_recalc_group_mask(dnotify_group); | ||
418 | |||
419 | mutex_unlock(&dnotify_mark_mutex); | ||
420 | fsnotify_put_mark(entry); | ||
421 | out_err: | ||
422 | if (new_entry) | ||
423 | fsnotify_put_mark(new_entry); | ||
424 | if (dn) | ||
425 | kmem_cache_free(dnotify_struct_cache, dn); | ||
426 | return error; | ||
181 | } | 427 | } |
182 | EXPORT_SYMBOL_GPL(dnotify_parent); | ||
183 | 428 | ||
184 | static int __init dnotify_init(void) | 429 | static int __init dnotify_init(void) |
185 | { | 430 | { |
186 | dn_cache = kmem_cache_create("dnotify_cache", | 431 | dnotify_struct_cache = KMEM_CACHE(dnotify_struct, SLAB_PANIC); |
187 | sizeof(struct dnotify_struct), 0, SLAB_PANIC, NULL); | 432 | dnotify_mark_entry_cache = KMEM_CACHE(dnotify_mark_entry, SLAB_PANIC); |
433 | |||
434 | dnotify_group = fsnotify_obtain_group(DNOTIFY_GROUP_NUM, | ||
435 | 0, &dnotify_fsnotify_ops); | ||
436 | if (IS_ERR(dnotify_group)) | ||
437 | panic("unable to allocate fsnotify group for dnotify\n"); | ||
188 | return 0; | 438 | return 0; |
189 | } | 439 | } |
190 | 440 | ||
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c new file mode 100644 index 000000000000..ec2f7bd76818 --- /dev/null +++ b/fs/notify/fsnotify.c | |||
@@ -0,0 +1,186 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com> | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or modify | ||
5 | * it under the terms of the GNU General Public License as published by | ||
6 | * the Free Software Foundation; either version 2, or (at your option) | ||
7 | * any later version. | ||
8 | * | ||
9 | * This program is distributed in the hope that it will be useful, | ||
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
12 | * GNU General Public License for more details. | ||
13 | * | ||
14 | * You should have received a copy of the GNU General Public License | ||
15 | * along with this program; see the file COPYING. If not, write to | ||
16 | * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | ||
17 | */ | ||
18 | |||
19 | #include <linux/dcache.h> | ||
20 | #include <linux/fs.h> | ||
21 | #include <linux/init.h> | ||
22 | #include <linux/module.h> | ||
23 | #include <linux/srcu.h> | ||
24 | |||
25 | #include <linux/fsnotify_backend.h> | ||
26 | #include "fsnotify.h" | ||
27 | |||
28 | /* | ||
29 | * Clear all of the marks on an inode when it is being evicted from core | ||
30 | */ | ||
31 | void __fsnotify_inode_delete(struct inode *inode) | ||
32 | { | ||
33 | fsnotify_clear_marks_by_inode(inode); | ||
34 | } | ||
35 | EXPORT_SYMBOL_GPL(__fsnotify_inode_delete); | ||
36 | |||
37 | /* | ||
38 | * Given an inode, first check if we care what happens to our children. Inotify | ||
39 | * and dnotify both tell their parents about events. If we care about any event | ||
40 | * on a child we run all of our children and set a dentry flag saying that the | ||
41 | * parent cares. Thus when an event happens on a child it can quickly tell if | ||
42 | * if there is a need to find a parent and send the event to the parent. | ||
43 | */ | ||
44 | void __fsnotify_update_child_dentry_flags(struct inode *inode) | ||
45 | { | ||
46 | struct dentry *alias; | ||
47 | int watched; | ||
48 | |||
49 | if (!S_ISDIR(inode->i_mode)) | ||
50 | return; | ||
51 | |||
52 | /* determine if the children should tell inode about their events */ | ||
53 | watched = fsnotify_inode_watches_children(inode); | ||
54 | |||
55 | spin_lock(&dcache_lock); | ||
56 | /* run all of the dentries associated with this inode. Since this is a | ||
57 | * directory, there damn well better only be one item on this list */ | ||
58 | list_for_each_entry(alias, &inode->i_dentry, d_alias) { | ||
59 | struct dentry *child; | ||
60 | |||
61 | /* run all of the children of the original inode and fix their | ||
62 | * d_flags to indicate parental interest (their parent is the | ||
63 | * original inode) */ | ||
64 | list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) { | ||
65 | if (!child->d_inode) | ||
66 | continue; | ||
67 | |||
68 | spin_lock(&child->d_lock); | ||
69 | if (watched) | ||
70 | child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; | ||
71 | else | ||
72 | child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; | ||
73 | spin_unlock(&child->d_lock); | ||
74 | } | ||
75 | } | ||
76 | spin_unlock(&dcache_lock); | ||
77 | } | ||
78 | |||
79 | /* Notify this dentry's parent about a child's events. */ | ||
80 | void __fsnotify_parent(struct dentry *dentry, __u32 mask) | ||
81 | { | ||
82 | struct dentry *parent; | ||
83 | struct inode *p_inode; | ||
84 | bool send = false; | ||
85 | bool should_update_children = false; | ||
86 | |||
87 | if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED)) | ||
88 | return; | ||
89 | |||
90 | spin_lock(&dentry->d_lock); | ||
91 | parent = dentry->d_parent; | ||
92 | p_inode = parent->d_inode; | ||
93 | |||
94 | if (fsnotify_inode_watches_children(p_inode)) { | ||
95 | if (p_inode->i_fsnotify_mask & mask) { | ||
96 | dget(parent); | ||
97 | send = true; | ||
98 | } | ||
99 | } else { | ||
100 | /* | ||
101 | * The parent doesn't care about events on it's children but | ||
102 | * at least one child thought it did. We need to run all the | ||
103 | * children and update their d_flags to let them know p_inode | ||
104 | * doesn't care about them any more. | ||
105 | */ | ||
106 | dget(parent); | ||
107 | should_update_children = true; | ||
108 | } | ||
109 | |||
110 | spin_unlock(&dentry->d_lock); | ||
111 | |||
112 | if (send) { | ||
113 | /* we are notifying a parent so come up with the new mask which | ||
114 | * specifies these are events which came from a child. */ | ||
115 | mask |= FS_EVENT_ON_CHILD; | ||
116 | |||
117 | fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE, | ||
118 | dentry->d_name.name, 0); | ||
119 | dput(parent); | ||
120 | } | ||
121 | |||
122 | if (unlikely(should_update_children)) { | ||
123 | __fsnotify_update_child_dentry_flags(p_inode); | ||
124 | dput(parent); | ||
125 | } | ||
126 | } | ||
127 | EXPORT_SYMBOL_GPL(__fsnotify_parent); | ||
128 | |||
129 | /* | ||
130 | * This is the main call to fsnotify. The VFS calls into hook specific functions | ||
131 | * in linux/fsnotify.h. Those functions then in turn call here. Here will call | ||
132 | * out to all of the registered fsnotify_group. Those groups can then use the | ||
133 | * notification event in whatever means they feel necessary. | ||
134 | */ | ||
135 | void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *file_name, u32 cookie) | ||
136 | { | ||
137 | struct fsnotify_group *group; | ||
138 | struct fsnotify_event *event = NULL; | ||
139 | int idx; | ||
140 | /* global tests shouldn't care about events on child only the specific event */ | ||
141 | __u32 test_mask = (mask & ~FS_EVENT_ON_CHILD); | ||
142 | |||
143 | if (list_empty(&fsnotify_groups)) | ||
144 | return; | ||
145 | |||
146 | if (!(test_mask & fsnotify_mask)) | ||
147 | return; | ||
148 | |||
149 | if (!(test_mask & to_tell->i_fsnotify_mask)) | ||
150 | return; | ||
151 | /* | ||
152 | * SRCU!! the groups list is very very much read only and the path is | ||
153 | * very hot. The VAST majority of events are not going to need to do | ||
154 | * anything other than walk the list so it's crazy to pre-allocate. | ||
155 | */ | ||
156 | idx = srcu_read_lock(&fsnotify_grp_srcu); | ||
157 | list_for_each_entry_rcu(group, &fsnotify_groups, group_list) { | ||
158 | if (test_mask & group->mask) { | ||
159 | if (!group->ops->should_send_event(group, to_tell, mask)) | ||
160 | continue; | ||
161 | if (!event) { | ||
162 | event = fsnotify_create_event(to_tell, mask, data, data_is, file_name, cookie); | ||
163 | /* shit, we OOM'd and now we can't tell, maybe | ||
164 | * someday someone else will want to do something | ||
165 | * here */ | ||
166 | if (!event) | ||
167 | break; | ||
168 | } | ||
169 | group->ops->handle_event(group, event); | ||
170 | } | ||
171 | } | ||
172 | srcu_read_unlock(&fsnotify_grp_srcu, idx); | ||
173 | /* | ||
174 | * fsnotify_create_event() took a reference so the event can't be cleaned | ||
175 | * up while we are still trying to add it to lists, drop that one. | ||
176 | */ | ||
177 | if (event) | ||
178 | fsnotify_put_event(event); | ||
179 | } | ||
180 | EXPORT_SYMBOL_GPL(fsnotify); | ||
181 | |||
182 | static __init int fsnotify_init(void) | ||
183 | { | ||
184 | return init_srcu_struct(&fsnotify_grp_srcu); | ||
185 | } | ||
186 | subsys_initcall(fsnotify_init); | ||
diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h new file mode 100644 index 000000000000..4dc240824b2d --- /dev/null +++ b/fs/notify/fsnotify.h | |||
@@ -0,0 +1,34 @@ | |||
1 | #ifndef __FS_NOTIFY_FSNOTIFY_H_ | ||
2 | #define __FS_NOTIFY_FSNOTIFY_H_ | ||
3 | |||
4 | #include <linux/list.h> | ||
5 | #include <linux/fsnotify.h> | ||
6 | #include <linux/srcu.h> | ||
7 | #include <linux/types.h> | ||
8 | |||
9 | /* protects reads of fsnotify_groups */ | ||
10 | extern struct srcu_struct fsnotify_grp_srcu; | ||
11 | /* all groups which receive fsnotify events */ | ||
12 | extern struct list_head fsnotify_groups; | ||
13 | /* all bitwise OR of all event types (FS_*) for all fsnotify_groups */ | ||
14 | extern __u32 fsnotify_mask; | ||
15 | |||
16 | /* destroy all events sitting in this groups notification queue */ | ||
17 | extern void fsnotify_flush_notify(struct fsnotify_group *group); | ||
18 | |||
19 | /* final kfree of a group */ | ||
20 | extern void fsnotify_final_destroy_group(struct fsnotify_group *group); | ||
21 | |||
22 | /* run the list of all marks associated with inode and flag them to be freed */ | ||
23 | extern void fsnotify_clear_marks_by_inode(struct inode *inode); | ||
24 | /* | ||
25 | * update the dentry->d_flags of all of inode's children to indicate if inode cares | ||
26 | * about events that happen to its children. | ||
27 | */ | ||
28 | extern void __fsnotify_update_child_dentry_flags(struct inode *inode); | ||
29 | |||
30 | /* allocate and destroy and event holder to attach events to notification/access queues */ | ||
31 | extern struct fsnotify_event_holder *fsnotify_alloc_event_holder(void); | ||
32 | extern void fsnotify_destroy_event_holder(struct fsnotify_event_holder *holder); | ||
33 | |||
34 | #endif /* __FS_NOTIFY_FSNOTIFY_H_ */ | ||
diff --git a/fs/notify/group.c b/fs/notify/group.c new file mode 100644 index 000000000000..0e1677144bc5 --- /dev/null +++ b/fs/notify/group.c | |||
@@ -0,0 +1,254 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com> | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or modify | ||
5 | * it under the terms of the GNU General Public License as published by | ||
6 | * the Free Software Foundation; either version 2, or (at your option) | ||
7 | * any later version. | ||
8 | * | ||
9 | * This program is distributed in the hope that it will be useful, | ||
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
12 | * GNU General Public License for more details. | ||
13 | * | ||
14 | * You should have received a copy of the GNU General Public License | ||
15 | * along with this program; see the file COPYING. If not, write to | ||
16 | * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | ||
17 | */ | ||
18 | |||
19 | #include <linux/list.h> | ||
20 | #include <linux/mutex.h> | ||
21 | #include <linux/slab.h> | ||
22 | #include <linux/srcu.h> | ||
23 | #include <linux/rculist.h> | ||
24 | #include <linux/wait.h> | ||
25 | |||
26 | #include <linux/fsnotify_backend.h> | ||
27 | #include "fsnotify.h" | ||
28 | |||
29 | #include <asm/atomic.h> | ||
30 | |||
31 | /* protects writes to fsnotify_groups and fsnotify_mask */ | ||
32 | static DEFINE_MUTEX(fsnotify_grp_mutex); | ||
33 | /* protects reads while running the fsnotify_groups list */ | ||
34 | struct srcu_struct fsnotify_grp_srcu; | ||
35 | /* all groups registered to receive filesystem notifications */ | ||
36 | LIST_HEAD(fsnotify_groups); | ||
37 | /* bitwise OR of all events (FS_*) interesting to some group on this system */ | ||
38 | __u32 fsnotify_mask; | ||
39 | |||
40 | /* | ||
41 | * When a new group registers or changes it's set of interesting events | ||
42 | * this function updates the fsnotify_mask to contain all interesting events | ||
43 | */ | ||
44 | void fsnotify_recalc_global_mask(void) | ||
45 | { | ||
46 | struct fsnotify_group *group; | ||
47 | __u32 mask = 0; | ||
48 | int idx; | ||
49 | |||
50 | idx = srcu_read_lock(&fsnotify_grp_srcu); | ||
51 | list_for_each_entry_rcu(group, &fsnotify_groups, group_list) | ||
52 | mask |= group->mask; | ||
53 | srcu_read_unlock(&fsnotify_grp_srcu, idx); | ||
54 | fsnotify_mask = mask; | ||
55 | } | ||
56 | |||
57 | /* | ||
58 | * Update the group->mask by running all of the marks associated with this | ||
59 | * group and finding the bitwise | of all of the mark->mask. If we change | ||
60 | * the group->mask we need to update the global mask of events interesting | ||
61 | * to the system. | ||
62 | */ | ||
63 | void fsnotify_recalc_group_mask(struct fsnotify_group *group) | ||
64 | { | ||
65 | __u32 mask = 0; | ||
66 | __u32 old_mask = group->mask; | ||
67 | struct fsnotify_mark_entry *entry; | ||
68 | |||
69 | spin_lock(&group->mark_lock); | ||
70 | list_for_each_entry(entry, &group->mark_entries, g_list) | ||
71 | mask |= entry->mask; | ||
72 | spin_unlock(&group->mark_lock); | ||
73 | |||
74 | group->mask = mask; | ||
75 | |||
76 | if (old_mask != mask) | ||
77 | fsnotify_recalc_global_mask(); | ||
78 | } | ||
79 | |||
80 | /* | ||
81 | * Take a reference to a group so things found under the fsnotify_grp_mutex | ||
82 | * can't get freed under us | ||
83 | */ | ||
84 | static void fsnotify_get_group(struct fsnotify_group *group) | ||
85 | { | ||
86 | atomic_inc(&group->refcnt); | ||
87 | } | ||
88 | |||
89 | /* | ||
90 | * Final freeing of a group | ||
91 | */ | ||
92 | void fsnotify_final_destroy_group(struct fsnotify_group *group) | ||
93 | { | ||
94 | /* clear the notification queue of all events */ | ||
95 | fsnotify_flush_notify(group); | ||
96 | |||
97 | if (group->ops->free_group_priv) | ||
98 | group->ops->free_group_priv(group); | ||
99 | |||
100 | kfree(group); | ||
101 | } | ||
102 | |||
103 | /* | ||
104 | * Trying to get rid of a group. We need to first get rid of any outstanding | ||
105 | * allocations and then free the group. Remember that fsnotify_clear_marks_by_group | ||
106 | * could miss marks that are being freed by inode and those marks could still | ||
107 | * hold a reference to this group (via group->num_marks) If we get into that | ||
108 | * situtation, the fsnotify_final_destroy_group will get called when that final | ||
109 | * mark is freed. | ||
110 | */ | ||
111 | static void fsnotify_destroy_group(struct fsnotify_group *group) | ||
112 | { | ||
113 | /* clear all inode mark entries for this group */ | ||
114 | fsnotify_clear_marks_by_group(group); | ||
115 | |||
116 | /* past the point of no return, matches the initial value of 1 */ | ||
117 | if (atomic_dec_and_test(&group->num_marks)) | ||
118 | fsnotify_final_destroy_group(group); | ||
119 | } | ||
120 | |||
121 | /* | ||
122 | * Remove this group from the global list of groups that will get events | ||
123 | * this can be done even if there are still references and things still using | ||
124 | * this group. This just stops the group from getting new events. | ||
125 | */ | ||
126 | static void __fsnotify_evict_group(struct fsnotify_group *group) | ||
127 | { | ||
128 | BUG_ON(!mutex_is_locked(&fsnotify_grp_mutex)); | ||
129 | |||
130 | if (group->on_group_list) | ||
131 | list_del_rcu(&group->group_list); | ||
132 | group->on_group_list = 0; | ||
133 | } | ||
134 | |||
135 | /* | ||
136 | * Called when a group is no longer interested in getting events. This can be | ||
137 | * used if a group is misbehaving or if for some reason a group should no longer | ||
138 | * get any filesystem events. | ||
139 | */ | ||
140 | void fsnotify_evict_group(struct fsnotify_group *group) | ||
141 | { | ||
142 | mutex_lock(&fsnotify_grp_mutex); | ||
143 | __fsnotify_evict_group(group); | ||
144 | mutex_unlock(&fsnotify_grp_mutex); | ||
145 | } | ||
146 | |||
147 | /* | ||
148 | * Drop a reference to a group. Free it if it's through. | ||
149 | */ | ||
150 | void fsnotify_put_group(struct fsnotify_group *group) | ||
151 | { | ||
152 | if (!atomic_dec_and_mutex_lock(&group->refcnt, &fsnotify_grp_mutex)) | ||
153 | return; | ||
154 | |||
155 | /* | ||
156 | * OK, now we know that there's no other users *and* we hold mutex, | ||
157 | * so no new references will appear | ||
158 | */ | ||
159 | __fsnotify_evict_group(group); | ||
160 | |||
161 | /* | ||
162 | * now it's off the list, so the only thing we might care about is | ||
163 | * srcu access.... | ||
164 | */ | ||
165 | mutex_unlock(&fsnotify_grp_mutex); | ||
166 | synchronize_srcu(&fsnotify_grp_srcu); | ||
167 | |||
168 | /* and now it is really dead. _Nothing_ could be seeing it */ | ||
169 | fsnotify_recalc_global_mask(); | ||
170 | fsnotify_destroy_group(group); | ||
171 | } | ||
172 | |||
173 | /* | ||
174 | * Simply run the fsnotify_groups list and find a group which matches | ||
175 | * the given parameters. If a group is found we take a reference to that | ||
176 | * group. | ||
177 | */ | ||
178 | static struct fsnotify_group *fsnotify_find_group(unsigned int group_num, __u32 mask, | ||
179 | const struct fsnotify_ops *ops) | ||
180 | { | ||
181 | struct fsnotify_group *group_iter; | ||
182 | struct fsnotify_group *group = NULL; | ||
183 | |||
184 | BUG_ON(!mutex_is_locked(&fsnotify_grp_mutex)); | ||
185 | |||
186 | list_for_each_entry_rcu(group_iter, &fsnotify_groups, group_list) { | ||
187 | if (group_iter->group_num == group_num) { | ||
188 | if ((group_iter->mask == mask) && | ||
189 | (group_iter->ops == ops)) { | ||
190 | fsnotify_get_group(group_iter); | ||
191 | group = group_iter; | ||
192 | } else | ||
193 | group = ERR_PTR(-EEXIST); | ||
194 | } | ||
195 | } | ||
196 | return group; | ||
197 | } | ||
198 | |||
199 | /* | ||
200 | * Either finds an existing group which matches the group_num, mask, and ops or | ||
201 | * creates a new group and adds it to the global group list. In either case we | ||
202 | * take a reference for the group returned. | ||
203 | */ | ||
204 | struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num, __u32 mask, | ||
205 | const struct fsnotify_ops *ops) | ||
206 | { | ||
207 | struct fsnotify_group *group, *tgroup; | ||
208 | |||
209 | /* very low use, simpler locking if we just always alloc */ | ||
210 | group = kmalloc(sizeof(struct fsnotify_group), GFP_KERNEL); | ||
211 | if (!group) | ||
212 | return ERR_PTR(-ENOMEM); | ||
213 | |||
214 | atomic_set(&group->refcnt, 1); | ||
215 | |||
216 | group->on_group_list = 0; | ||
217 | group->group_num = group_num; | ||
218 | group->mask = mask; | ||
219 | |||
220 | mutex_init(&group->notification_mutex); | ||
221 | INIT_LIST_HEAD(&group->notification_list); | ||
222 | init_waitqueue_head(&group->notification_waitq); | ||
223 | group->q_len = 0; | ||
224 | group->max_events = UINT_MAX; | ||
225 | |||
226 | spin_lock_init(&group->mark_lock); | ||
227 | atomic_set(&group->num_marks, 0); | ||
228 | INIT_LIST_HEAD(&group->mark_entries); | ||
229 | |||
230 | group->ops = ops; | ||
231 | |||
232 | mutex_lock(&fsnotify_grp_mutex); | ||
233 | tgroup = fsnotify_find_group(group_num, mask, ops); | ||
234 | if (tgroup) { | ||
235 | /* group already exists */ | ||
236 | mutex_unlock(&fsnotify_grp_mutex); | ||
237 | /* destroy the new one we made */ | ||
238 | fsnotify_put_group(group); | ||
239 | return tgroup; | ||
240 | } | ||
241 | |||
242 | /* group not found, add a new one */ | ||
243 | list_add_rcu(&group->group_list, &fsnotify_groups); | ||
244 | group->on_group_list = 1; | ||
245 | /* being on the fsnotify_groups list holds one num_marks */ | ||
246 | atomic_inc(&group->num_marks); | ||
247 | |||
248 | mutex_unlock(&fsnotify_grp_mutex); | ||
249 | |||
250 | if (mask) | ||
251 | fsnotify_recalc_global_mask(); | ||
252 | |||
253 | return group; | ||
254 | } | ||
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c new file mode 100644 index 000000000000..c8a07c65482b --- /dev/null +++ b/fs/notify/inode_mark.c | |||
@@ -0,0 +1,426 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com> | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or modify | ||
5 | * it under the terms of the GNU General Public License as published by | ||
6 | * the Free Software Foundation; either version 2, or (at your option) | ||
7 | * any later version. | ||
8 | * | ||
9 | * This program is distributed in the hope that it will be useful, | ||
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
12 | * GNU General Public License for more details. | ||
13 | * | ||
14 | * You should have received a copy of the GNU General Public License | ||
15 | * along with this program; see the file COPYING. If not, write to | ||
16 | * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | ||
17 | */ | ||
18 | |||
19 | /* | ||
20 | * fsnotify inode mark locking/lifetime/and refcnting | ||
21 | * | ||
22 | * REFCNT: | ||
23 | * The mark->refcnt tells how many "things" in the kernel currently are | ||
24 | * referencing this object. The object typically will live inside the kernel | ||
25 | * with a refcnt of 2, one for each list it is on (i_list, g_list). Any task | ||
26 | * which can find this object holding the appropriete locks, can take a reference | ||
27 | * and the object itself is guarenteed to survive until the reference is dropped. | ||
28 | * | ||
29 | * LOCKING: | ||
30 | * There are 3 spinlocks involved with fsnotify inode marks and they MUST | ||
31 | * be taken in order as follows: | ||
32 | * | ||
33 | * entry->lock | ||
34 | * group->mark_lock | ||
35 | * inode->i_lock | ||
36 | * | ||
37 | * entry->lock protects 2 things, entry->group and entry->inode. You must hold | ||
38 | * that lock to dereference either of these things (they could be NULL even with | ||
39 | * the lock) | ||
40 | * | ||
41 | * group->mark_lock protects the mark_entries list anchored inside a given group | ||
42 | * and each entry is hooked via the g_list. It also sorta protects the | ||
43 | * free_g_list, which when used is anchored by a private list on the stack of the | ||
44 | * task which held the group->mark_lock. | ||
45 | * | ||
46 | * inode->i_lock protects the i_fsnotify_mark_entries list anchored inside a | ||
47 | * given inode and each entry is hooked via the i_list. (and sorta the | ||
48 | * free_i_list) | ||
49 | * | ||
50 | * | ||
51 | * LIFETIME: | ||
52 | * Inode marks survive between when they are added to an inode and when their | ||
53 | * refcnt==0. | ||
54 | * | ||
55 | * The inode mark can be cleared for a number of different reasons including: | ||
56 | * - The inode is unlinked for the last time. (fsnotify_inode_remove) | ||
57 | * - The inode is being evicted from cache. (fsnotify_inode_delete) | ||
58 | * - The fs the inode is on is unmounted. (fsnotify_inode_delete/fsnotify_unmount_inodes) | ||
59 | * - Something explicitly requests that it be removed. (fsnotify_destroy_mark_by_entry) | ||
60 | * - The fsnotify_group associated with the mark is going away and all such marks | ||
61 | * need to be cleaned up. (fsnotify_clear_marks_by_group) | ||
62 | * | ||
63 | * Worst case we are given an inode and need to clean up all the marks on that | ||
64 | * inode. We take i_lock and walk the i_fsnotify_mark_entries safely. For each | ||
65 | * mark on the list we take a reference (so the mark can't disappear under us). | ||
66 | * We remove that mark form the inode's list of marks and we add this mark to a | ||
67 | * private list anchored on the stack using i_free_list; At this point we no | ||
68 | * longer fear anything finding the mark using the inode's list of marks. | ||
69 | * | ||
70 | * We can safely and locklessly run the private list on the stack of everything | ||
71 | * we just unattached from the original inode. For each mark on the private list | ||
72 | * we grab the mark-> and can thus dereference mark->group and mark->inode. If | ||
73 | * we see the group and inode are not NULL we take those locks. Now holding all | ||
74 | * 3 locks we can completely remove the mark from other tasks finding it in the | ||
75 | * future. Remember, 10 things might already be referencing this mark, but they | ||
76 | * better be holding a ref. We drop our reference we took before we unhooked it | ||
77 | * from the inode. When the ref hits 0 we can free the mark. | ||
78 | * | ||
79 | * Very similarly for freeing by group, except we use free_g_list. | ||
80 | * | ||
81 | * This has the very interesting property of being able to run concurrently with | ||
82 | * any (or all) other directions. | ||
83 | */ | ||
84 | |||
85 | #include <linux/fs.h> | ||
86 | #include <linux/init.h> | ||
87 | #include <linux/kernel.h> | ||
88 | #include <linux/module.h> | ||
89 | #include <linux/mutex.h> | ||
90 | #include <linux/slab.h> | ||
91 | #include <linux/spinlock.h> | ||
92 | #include <linux/writeback.h> /* for inode_lock */ | ||
93 | |||
94 | #include <asm/atomic.h> | ||
95 | |||
96 | #include <linux/fsnotify_backend.h> | ||
97 | #include "fsnotify.h" | ||
98 | |||
99 | void fsnotify_get_mark(struct fsnotify_mark_entry *entry) | ||
100 | { | ||
101 | atomic_inc(&entry->refcnt); | ||
102 | } | ||
103 | |||
104 | void fsnotify_put_mark(struct fsnotify_mark_entry *entry) | ||
105 | { | ||
106 | if (atomic_dec_and_test(&entry->refcnt)) | ||
107 | entry->free_mark(entry); | ||
108 | } | ||
109 | |||
110 | /* | ||
111 | * Recalculate the mask of events relevant to a given inode locked. | ||
112 | */ | ||
113 | static void fsnotify_recalc_inode_mask_locked(struct inode *inode) | ||
114 | { | ||
115 | struct fsnotify_mark_entry *entry; | ||
116 | struct hlist_node *pos; | ||
117 | __u32 new_mask = 0; | ||
118 | |||
119 | assert_spin_locked(&inode->i_lock); | ||
120 | |||
121 | hlist_for_each_entry(entry, pos, &inode->i_fsnotify_mark_entries, i_list) | ||
122 | new_mask |= entry->mask; | ||
123 | inode->i_fsnotify_mask = new_mask; | ||
124 | } | ||
125 | |||
126 | /* | ||
127 | * Recalculate the inode->i_fsnotify_mask, or the mask of all FS_* event types | ||
128 | * any notifier is interested in hearing for this inode. | ||
129 | */ | ||
130 | void fsnotify_recalc_inode_mask(struct inode *inode) | ||
131 | { | ||
132 | spin_lock(&inode->i_lock); | ||
133 | fsnotify_recalc_inode_mask_locked(inode); | ||
134 | spin_unlock(&inode->i_lock); | ||
135 | |||
136 | __fsnotify_update_child_dentry_flags(inode); | ||
137 | } | ||
138 | |||
139 | /* | ||
140 | * Any time a mark is getting freed we end up here. | ||
141 | * The caller had better be holding a reference to this mark so we don't actually | ||
142 | * do the final put under the entry->lock | ||
143 | */ | ||
144 | void fsnotify_destroy_mark_by_entry(struct fsnotify_mark_entry *entry) | ||
145 | { | ||
146 | struct fsnotify_group *group; | ||
147 | struct inode *inode; | ||
148 | |||
149 | spin_lock(&entry->lock); | ||
150 | |||
151 | group = entry->group; | ||
152 | inode = entry->inode; | ||
153 | |||
154 | BUG_ON(group && !inode); | ||
155 | BUG_ON(!group && inode); | ||
156 | |||
157 | /* if !group something else already marked this to die */ | ||
158 | if (!group) { | ||
159 | spin_unlock(&entry->lock); | ||
160 | return; | ||
161 | } | ||
162 | |||
163 | /* 1 from caller and 1 for being on i_list/g_list */ | ||
164 | BUG_ON(atomic_read(&entry->refcnt) < 2); | ||
165 | |||
166 | spin_lock(&group->mark_lock); | ||
167 | spin_lock(&inode->i_lock); | ||
168 | |||
169 | hlist_del_init(&entry->i_list); | ||
170 | entry->inode = NULL; | ||
171 | |||
172 | list_del_init(&entry->g_list); | ||
173 | entry->group = NULL; | ||
174 | |||
175 | fsnotify_put_mark(entry); /* for i_list and g_list */ | ||
176 | |||
177 | /* | ||
178 | * this mark is now off the inode->i_fsnotify_mark_entries list and we | ||
179 | * hold the inode->i_lock, so this is the perfect time to update the | ||
180 | * inode->i_fsnotify_mask | ||
181 | */ | ||
182 | fsnotify_recalc_inode_mask_locked(inode); | ||
183 | |||
184 | spin_unlock(&inode->i_lock); | ||
185 | spin_unlock(&group->mark_lock); | ||
186 | spin_unlock(&entry->lock); | ||
187 | |||
188 | /* | ||
189 | * Some groups like to know that marks are being freed. This is a | ||
190 | * callback to the group function to let it know that this entry | ||
191 | * is being freed. | ||
192 | */ | ||
193 | if (group->ops->freeing_mark) | ||
194 | group->ops->freeing_mark(entry, group); | ||
195 | |||
196 | /* | ||
197 | * __fsnotify_update_child_dentry_flags(inode); | ||
198 | * | ||
199 | * I really want to call that, but we can't, we have no idea if the inode | ||
200 | * still exists the second we drop the entry->lock. | ||
201 | * | ||
202 | * The next time an event arrive to this inode from one of it's children | ||
203 | * __fsnotify_parent will see that the inode doesn't care about it's | ||
204 | * children and will update all of these flags then. So really this | ||
205 | * is just a lazy update (and could be a perf win...) | ||
206 | */ | ||
207 | |||
208 | |||
209 | iput(inode); | ||
210 | |||
211 | /* | ||
212 | * it's possible that this group tried to destroy itself, but this | ||
213 | * this mark was simultaneously being freed by inode. If that's the | ||
214 | * case, we finish freeing the group here. | ||
215 | */ | ||
216 | if (unlikely(atomic_dec_and_test(&group->num_marks))) | ||
217 | fsnotify_final_destroy_group(group); | ||
218 | } | ||
219 | |||
220 | /* | ||
221 | * Given a group, destroy all of the marks associated with that group. | ||
222 | */ | ||
223 | void fsnotify_clear_marks_by_group(struct fsnotify_group *group) | ||
224 | { | ||
225 | struct fsnotify_mark_entry *lentry, *entry; | ||
226 | LIST_HEAD(free_list); | ||
227 | |||
228 | spin_lock(&group->mark_lock); | ||
229 | list_for_each_entry_safe(entry, lentry, &group->mark_entries, g_list) { | ||
230 | list_add(&entry->free_g_list, &free_list); | ||
231 | list_del_init(&entry->g_list); | ||
232 | fsnotify_get_mark(entry); | ||
233 | } | ||
234 | spin_unlock(&group->mark_lock); | ||
235 | |||
236 | list_for_each_entry_safe(entry, lentry, &free_list, free_g_list) { | ||
237 | fsnotify_destroy_mark_by_entry(entry); | ||
238 | fsnotify_put_mark(entry); | ||
239 | } | ||
240 | } | ||
241 | |||
242 | /* | ||
243 | * Given an inode, destroy all of the marks associated with that inode. | ||
244 | */ | ||
245 | void fsnotify_clear_marks_by_inode(struct inode *inode) | ||
246 | { | ||
247 | struct fsnotify_mark_entry *entry, *lentry; | ||
248 | struct hlist_node *pos, *n; | ||
249 | LIST_HEAD(free_list); | ||
250 | |||
251 | spin_lock(&inode->i_lock); | ||
252 | hlist_for_each_entry_safe(entry, pos, n, &inode->i_fsnotify_mark_entries, i_list) { | ||
253 | list_add(&entry->free_i_list, &free_list); | ||
254 | hlist_del_init(&entry->i_list); | ||
255 | fsnotify_get_mark(entry); | ||
256 | } | ||
257 | spin_unlock(&inode->i_lock); | ||
258 | |||
259 | list_for_each_entry_safe(entry, lentry, &free_list, free_i_list) { | ||
260 | fsnotify_destroy_mark_by_entry(entry); | ||
261 | fsnotify_put_mark(entry); | ||
262 | } | ||
263 | } | ||
264 | |||
265 | /* | ||
266 | * given a group and inode, find the mark associated with that combination. | ||
267 | * if found take a reference to that mark and return it, else return NULL | ||
268 | */ | ||
269 | struct fsnotify_mark_entry *fsnotify_find_mark_entry(struct fsnotify_group *group, | ||
270 | struct inode *inode) | ||
271 | { | ||
272 | struct fsnotify_mark_entry *entry; | ||
273 | struct hlist_node *pos; | ||
274 | |||
275 | assert_spin_locked(&inode->i_lock); | ||
276 | |||
277 | hlist_for_each_entry(entry, pos, &inode->i_fsnotify_mark_entries, i_list) { | ||
278 | if (entry->group == group) { | ||
279 | fsnotify_get_mark(entry); | ||
280 | return entry; | ||
281 | } | ||
282 | } | ||
283 | return NULL; | ||
284 | } | ||
285 | |||
286 | /* | ||
287 | * Nothing fancy, just initialize lists and locks and counters. | ||
288 | */ | ||
289 | void fsnotify_init_mark(struct fsnotify_mark_entry *entry, | ||
290 | void (*free_mark)(struct fsnotify_mark_entry *entry)) | ||
291 | |||
292 | { | ||
293 | spin_lock_init(&entry->lock); | ||
294 | atomic_set(&entry->refcnt, 1); | ||
295 | INIT_HLIST_NODE(&entry->i_list); | ||
296 | entry->group = NULL; | ||
297 | entry->mask = 0; | ||
298 | entry->inode = NULL; | ||
299 | entry->free_mark = free_mark; | ||
300 | } | ||
301 | |||
302 | /* | ||
303 | * Attach an initialized mark entry to a given group and inode. | ||
304 | * These marks may be used for the fsnotify backend to determine which | ||
305 | * event types should be delivered to which group and for which inodes. | ||
306 | */ | ||
307 | int fsnotify_add_mark(struct fsnotify_mark_entry *entry, | ||
308 | struct fsnotify_group *group, struct inode *inode) | ||
309 | { | ||
310 | struct fsnotify_mark_entry *lentry; | ||
311 | int ret = 0; | ||
312 | |||
313 | inode = igrab(inode); | ||
314 | if (unlikely(!inode)) | ||
315 | return -EINVAL; | ||
316 | |||
317 | /* | ||
318 | * LOCKING ORDER!!!! | ||
319 | * entry->lock | ||
320 | * group->mark_lock | ||
321 | * inode->i_lock | ||
322 | */ | ||
323 | spin_lock(&entry->lock); | ||
324 | spin_lock(&group->mark_lock); | ||
325 | spin_lock(&inode->i_lock); | ||
326 | |||
327 | entry->group = group; | ||
328 | entry->inode = inode; | ||
329 | |||
330 | lentry = fsnotify_find_mark_entry(group, inode); | ||
331 | if (!lentry) { | ||
332 | hlist_add_head(&entry->i_list, &inode->i_fsnotify_mark_entries); | ||
333 | list_add(&entry->g_list, &group->mark_entries); | ||
334 | |||
335 | fsnotify_get_mark(entry); /* for i_list and g_list */ | ||
336 | |||
337 | atomic_inc(&group->num_marks); | ||
338 | |||
339 | fsnotify_recalc_inode_mask_locked(inode); | ||
340 | } | ||
341 | |||
342 | spin_unlock(&inode->i_lock); | ||
343 | spin_unlock(&group->mark_lock); | ||
344 | spin_unlock(&entry->lock); | ||
345 | |||
346 | if (lentry) { | ||
347 | ret = -EEXIST; | ||
348 | iput(inode); | ||
349 | fsnotify_put_mark(lentry); | ||
350 | } else { | ||
351 | __fsnotify_update_child_dentry_flags(inode); | ||
352 | } | ||
353 | |||
354 | return ret; | ||
355 | } | ||
356 | |||
357 | /** | ||
358 | * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes. | ||
359 | * @list: list of inodes being unmounted (sb->s_inodes) | ||
360 | * | ||
361 | * Called with inode_lock held, protecting the unmounting super block's list | ||
362 | * of inodes, and with iprune_mutex held, keeping shrink_icache_memory() at bay. | ||
363 | * We temporarily drop inode_lock, however, and CAN block. | ||
364 | */ | ||
365 | void fsnotify_unmount_inodes(struct list_head *list) | ||
366 | { | ||
367 | struct inode *inode, *next_i, *need_iput = NULL; | ||
368 | |||
369 | list_for_each_entry_safe(inode, next_i, list, i_sb_list) { | ||
370 | struct inode *need_iput_tmp; | ||
371 | |||
372 | /* | ||
373 | * We cannot __iget() an inode in state I_CLEAR, I_FREEING, | ||
374 | * I_WILL_FREE, or I_NEW which is fine because by that point | ||
375 | * the inode cannot have any associated watches. | ||
376 | */ | ||
377 | if (inode->i_state & (I_CLEAR|I_FREEING|I_WILL_FREE|I_NEW)) | ||
378 | continue; | ||
379 | |||
380 | /* | ||
381 | * If i_count is zero, the inode cannot have any watches and | ||
382 | * doing an __iget/iput with MS_ACTIVE clear would actually | ||
383 | * evict all inodes with zero i_count from icache which is | ||
384 | * unnecessarily violent and may in fact be illegal to do. | ||
385 | */ | ||
386 | if (!atomic_read(&inode->i_count)) | ||
387 | continue; | ||
388 | |||
389 | need_iput_tmp = need_iput; | ||
390 | need_iput = NULL; | ||
391 | |||
392 | /* In case fsnotify_inode_delete() drops a reference. */ | ||
393 | if (inode != need_iput_tmp) | ||
394 | __iget(inode); | ||
395 | else | ||
396 | need_iput_tmp = NULL; | ||
397 | |||
398 | /* In case the dropping of a reference would nuke next_i. */ | ||
399 | if ((&next_i->i_sb_list != list) && | ||
400 | atomic_read(&next_i->i_count) && | ||
401 | !(next_i->i_state & (I_CLEAR | I_FREEING | I_WILL_FREE))) { | ||
402 | __iget(next_i); | ||
403 | need_iput = next_i; | ||
404 | } | ||
405 | |||
406 | /* | ||
407 | * We can safely drop inode_lock here because we hold | ||
408 | * references on both inode and next_i. Also no new inodes | ||
409 | * will be added since the umount has begun. Finally, | ||
410 | * iprune_mutex keeps shrink_icache_memory() away. | ||
411 | */ | ||
412 | spin_unlock(&inode_lock); | ||
413 | |||
414 | if (need_iput_tmp) | ||
415 | iput(need_iput_tmp); | ||
416 | |||
417 | /* for each watch, send FS_UNMOUNT and then remove it */ | ||
418 | fsnotify(inode, FS_UNMOUNT, inode, FSNOTIFY_EVENT_INODE, NULL, 0); | ||
419 | |||
420 | fsnotify_inode_delete(inode); | ||
421 | |||
422 | iput(inode); | ||
423 | |||
424 | spin_lock(&inode_lock); | ||
425 | } | ||
426 | } | ||
diff --git a/fs/notify/inotify/Kconfig b/fs/notify/inotify/Kconfig index 446792841023..5356884289a1 100644 --- a/fs/notify/inotify/Kconfig +++ b/fs/notify/inotify/Kconfig | |||
@@ -1,26 +1,30 @@ | |||
1 | config INOTIFY | 1 | config INOTIFY |
2 | bool "Inotify file change notification support" | 2 | bool "Inotify file change notification support" |
3 | default y | 3 | default n |
4 | ---help--- | 4 | ---help--- |
5 | Say Y here to enable inotify support. Inotify is a file change | 5 | Say Y here to enable legacy in kernel inotify support. Inotify is a |
6 | notification system and a replacement for dnotify. Inotify fixes | 6 | file change notification system. It is a replacement for dnotify. |
7 | numerous shortcomings in dnotify and introduces several new features | 7 | This option only provides the legacy inotify in kernel API. There |
8 | including multiple file events, one-shot support, and unmount | 8 | are no in tree kernel users of this interface since it is deprecated. |
9 | notification. | 9 | You only need this if you are loading an out of tree kernel module |
10 | that uses inotify. | ||
10 | 11 | ||
11 | For more information, see <file:Documentation/filesystems/inotify.txt> | 12 | For more information, see <file:Documentation/filesystems/inotify.txt> |
12 | 13 | ||
13 | If unsure, say Y. | 14 | If unsure, say N. |
14 | 15 | ||
15 | config INOTIFY_USER | 16 | config INOTIFY_USER |
16 | bool "Inotify support for userspace" | 17 | bool "Inotify support for userspace" |
17 | depends on INOTIFY | 18 | depends on FSNOTIFY |
18 | default y | 19 | default y |
19 | ---help--- | 20 | ---help--- |
20 | Say Y here to enable inotify support for userspace, including the | 21 | Say Y here to enable inotify support for userspace, including the |
21 | associated system calls. Inotify allows monitoring of both files and | 22 | associated system calls. Inotify allows monitoring of both files and |
22 | directories via a single open fd. Events are read from the file | 23 | directories via a single open fd. Events are read from the file |
23 | descriptor, which is also select()- and poll()-able. | 24 | descriptor, which is also select()- and poll()-able. |
25 | Inotify fixes numerous shortcomings in dnotify and introduces several | ||
26 | new features including multiple file events, one-shot support, and | ||
27 | unmount notification. | ||
24 | 28 | ||
25 | For more information, see <file:Documentation/filesystems/inotify.txt> | 29 | For more information, see <file:Documentation/filesystems/inotify.txt> |
26 | 30 | ||
diff --git a/fs/notify/inotify/Makefile b/fs/notify/inotify/Makefile index e290f3bb9d8d..943828171362 100644 --- a/fs/notify/inotify/Makefile +++ b/fs/notify/inotify/Makefile | |||
@@ -1,2 +1,2 @@ | |||
1 | obj-$(CONFIG_INOTIFY) += inotify.o | 1 | obj-$(CONFIG_INOTIFY) += inotify.o |
2 | obj-$(CONFIG_INOTIFY_USER) += inotify_user.o | 2 | obj-$(CONFIG_INOTIFY_USER) += inotify_fsnotify.o inotify_user.o |
diff --git a/fs/notify/inotify/inotify.c b/fs/notify/inotify/inotify.c index 220c13f0d73d..40b1cf914ccb 100644 --- a/fs/notify/inotify/inotify.c +++ b/fs/notify/inotify/inotify.c | |||
@@ -32,6 +32,7 @@ | |||
32 | #include <linux/list.h> | 32 | #include <linux/list.h> |
33 | #include <linux/writeback.h> | 33 | #include <linux/writeback.h> |
34 | #include <linux/inotify.h> | 34 | #include <linux/inotify.h> |
35 | #include <linux/fsnotify_backend.h> | ||
35 | 36 | ||
36 | static atomic_t inotify_cookie; | 37 | static atomic_t inotify_cookie; |
37 | 38 | ||
@@ -905,6 +906,25 @@ EXPORT_SYMBOL_GPL(inotify_rm_watch); | |||
905 | */ | 906 | */ |
906 | static int __init inotify_setup(void) | 907 | static int __init inotify_setup(void) |
907 | { | 908 | { |
909 | BUILD_BUG_ON(IN_ACCESS != FS_ACCESS); | ||
910 | BUILD_BUG_ON(IN_MODIFY != FS_MODIFY); | ||
911 | BUILD_BUG_ON(IN_ATTRIB != FS_ATTRIB); | ||
912 | BUILD_BUG_ON(IN_CLOSE_WRITE != FS_CLOSE_WRITE); | ||
913 | BUILD_BUG_ON(IN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE); | ||
914 | BUILD_BUG_ON(IN_OPEN != FS_OPEN); | ||
915 | BUILD_BUG_ON(IN_MOVED_FROM != FS_MOVED_FROM); | ||
916 | BUILD_BUG_ON(IN_MOVED_TO != FS_MOVED_TO); | ||
917 | BUILD_BUG_ON(IN_CREATE != FS_CREATE); | ||
918 | BUILD_BUG_ON(IN_DELETE != FS_DELETE); | ||
919 | BUILD_BUG_ON(IN_DELETE_SELF != FS_DELETE_SELF); | ||
920 | BUILD_BUG_ON(IN_MOVE_SELF != FS_MOVE_SELF); | ||
921 | BUILD_BUG_ON(IN_Q_OVERFLOW != FS_Q_OVERFLOW); | ||
922 | |||
923 | BUILD_BUG_ON(IN_UNMOUNT != FS_UNMOUNT); | ||
924 | BUILD_BUG_ON(IN_ISDIR != FS_IN_ISDIR); | ||
925 | BUILD_BUG_ON(IN_IGNORED != FS_IN_IGNORED); | ||
926 | BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT); | ||
927 | |||
908 | atomic_set(&inotify_cookie, 0); | 928 | atomic_set(&inotify_cookie, 0); |
909 | 929 | ||
910 | return 0; | 930 | return 0; |
diff --git a/fs/notify/inotify/inotify.h b/fs/notify/inotify/inotify.h new file mode 100644 index 000000000000..ea2605a58b8a --- /dev/null +++ b/fs/notify/inotify/inotify.h | |||
@@ -0,0 +1,21 @@ | |||
1 | #include <linux/fsnotify_backend.h> | ||
2 | #include <linux/inotify.h> | ||
3 | #include <linux/slab.h> /* struct kmem_cache */ | ||
4 | |||
5 | extern struct kmem_cache *event_priv_cachep; | ||
6 | |||
7 | struct inotify_event_private_data { | ||
8 | struct fsnotify_event_private_data fsnotify_event_priv_data; | ||
9 | int wd; | ||
10 | }; | ||
11 | |||
12 | struct inotify_inode_mark_entry { | ||
13 | /* fsnotify_mark_entry MUST be the first thing */ | ||
14 | struct fsnotify_mark_entry fsn_entry; | ||
15 | int wd; | ||
16 | }; | ||
17 | |||
18 | extern void inotify_destroy_mark_entry(struct fsnotify_mark_entry *entry, struct fsnotify_group *group); | ||
19 | extern void inotify_free_event_priv(struct fsnotify_event_private_data *event_priv); | ||
20 | |||
21 | extern const struct fsnotify_ops inotify_fsnotify_ops; | ||
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c new file mode 100644 index 000000000000..7ef75b83247e --- /dev/null +++ b/fs/notify/inotify/inotify_fsnotify.c | |||
@@ -0,0 +1,138 @@ | |||
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 | |||
25 | #include <linux/fs.h> /* struct inode */ | ||
26 | #include <linux/fsnotify_backend.h> | ||
27 | #include <linux/inotify.h> | ||
28 | #include <linux/path.h> /* struct path */ | ||
29 | #include <linux/slab.h> /* kmem_* */ | ||
30 | #include <linux/types.h> | ||
31 | |||
32 | #include "inotify.h" | ||
33 | |||
34 | static int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_event *event) | ||
35 | { | ||
36 | struct fsnotify_mark_entry *entry; | ||
37 | struct inotify_inode_mark_entry *ientry; | ||
38 | struct inode *to_tell; | ||
39 | struct inotify_event_private_data *event_priv; | ||
40 | struct fsnotify_event_private_data *fsn_event_priv; | ||
41 | int wd, ret; | ||
42 | |||
43 | to_tell = event->to_tell; | ||
44 | |||
45 | spin_lock(&to_tell->i_lock); | ||
46 | entry = fsnotify_find_mark_entry(group, to_tell); | ||
47 | spin_unlock(&to_tell->i_lock); | ||
48 | /* race with watch removal? We already passes should_send */ | ||
49 | if (unlikely(!entry)) | ||
50 | return 0; | ||
51 | ientry = container_of(entry, struct inotify_inode_mark_entry, | ||
52 | fsn_entry); | ||
53 | wd = ientry->wd; | ||
54 | |||
55 | event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL); | ||
56 | if (unlikely(!event_priv)) | ||
57 | return -ENOMEM; | ||
58 | |||
59 | fsn_event_priv = &event_priv->fsnotify_event_priv_data; | ||
60 | |||
61 | fsn_event_priv->group = group; | ||
62 | event_priv->wd = wd; | ||
63 | |||
64 | ret = fsnotify_add_notify_event(group, event, fsn_event_priv); | ||
65 | /* EEXIST is not an error */ | ||
66 | if (ret == -EEXIST) | ||
67 | ret = 0; | ||
68 | |||
69 | /* did event_priv get attached? */ | ||
70 | if (list_empty(&fsn_event_priv->event_list)) | ||
71 | inotify_free_event_priv(fsn_event_priv); | ||
72 | |||
73 | /* | ||
74 | * If we hold the entry until after the event is on the queue | ||
75 | * IN_IGNORED won't be able to pass this event in the queue | ||
76 | */ | ||
77 | fsnotify_put_mark(entry); | ||
78 | |||
79 | return ret; | ||
80 | } | ||
81 | |||
82 | static void inotify_freeing_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group) | ||
83 | { | ||
84 | inotify_destroy_mark_entry(entry, group); | ||
85 | } | ||
86 | |||
87 | static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, __u32 mask) | ||
88 | { | ||
89 | struct fsnotify_mark_entry *entry; | ||
90 | bool send; | ||
91 | |||
92 | spin_lock(&inode->i_lock); | ||
93 | entry = fsnotify_find_mark_entry(group, inode); | ||
94 | spin_unlock(&inode->i_lock); | ||
95 | if (!entry) | ||
96 | return false; | ||
97 | |||
98 | mask = (mask & ~FS_EVENT_ON_CHILD); | ||
99 | send = (entry->mask & mask); | ||
100 | |||
101 | /* find took a reference */ | ||
102 | fsnotify_put_mark(entry); | ||
103 | |||
104 | return send; | ||
105 | } | ||
106 | |||
107 | static int idr_callback(int id, void *p, void *data) | ||
108 | { | ||
109 | BUG(); | ||
110 | return 0; | ||
111 | } | ||
112 | |||
113 | static void inotify_free_group_priv(struct fsnotify_group *group) | ||
114 | { | ||
115 | /* ideally the idr is empty and we won't hit the BUG in teh callback */ | ||
116 | idr_for_each(&group->inotify_data.idr, idr_callback, NULL); | ||
117 | idr_remove_all(&group->inotify_data.idr); | ||
118 | idr_destroy(&group->inotify_data.idr); | ||
119 | } | ||
120 | |||
121 | void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv) | ||
122 | { | ||
123 | struct inotify_event_private_data *event_priv; | ||
124 | |||
125 | |||
126 | event_priv = container_of(fsn_event_priv, struct inotify_event_private_data, | ||
127 | fsnotify_event_priv_data); | ||
128 | |||
129 | kmem_cache_free(event_priv_cachep, event_priv); | ||
130 | } | ||
131 | |||
132 | const struct fsnotify_ops inotify_fsnotify_ops = { | ||
133 | .handle_event = inotify_handle_event, | ||
134 | .should_send_event = inotify_should_send_event, | ||
135 | .free_group_priv = inotify_free_group_priv, | ||
136 | .free_event_priv = inotify_free_event_priv, | ||
137 | .freeing_mark = inotify_freeing_mark, | ||
138 | }; | ||
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index 1634319e2404..982a412ac5bc 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c | |||
@@ -8,6 +8,9 @@ | |||
8 | * Copyright (C) 2005 John McCutchan | 8 | * Copyright (C) 2005 John McCutchan |
9 | * Copyright 2006 Hewlett-Packard Development Company, L.P. | 9 | * Copyright 2006 Hewlett-Packard Development Company, L.P. |
10 | * | 10 | * |
11 | * Copyright (C) 2009 Eric Paris <Red Hat Inc> | ||
12 | * inotify was largely rewriten to make use of the fsnotify infrastructure | ||
13 | * | ||
11 | * This program is free software; you can redistribute it and/or modify it | 14 | * This program is free software; you can redistribute it and/or modify it |
12 | * under the terms of the GNU General Public License as published by the | 15 | * under the terms of the GNU General Public License as published by the |
13 | * Free Software Foundation; either version 2, or (at your option) any | 16 | * Free Software Foundation; either version 2, or (at your option) any |
@@ -19,94 +22,48 @@ | |||
19 | * General Public License for more details. | 22 | * General Public License for more details. |
20 | */ | 23 | */ |
21 | 24 | ||
22 | #include <linux/kernel.h> | ||
23 | #include <linux/sched.h> | ||
24 | #include <linux/slab.h> | ||
25 | #include <linux/fs.h> | ||
26 | #include <linux/file.h> | 25 | #include <linux/file.h> |
27 | #include <linux/mount.h> | 26 | #include <linux/fs.h> /* struct inode */ |
28 | #include <linux/namei.h> | 27 | #include <linux/fsnotify_backend.h> |
29 | #include <linux/poll.h> | 28 | #include <linux/idr.h> |
30 | #include <linux/init.h> | 29 | #include <linux/init.h> /* module_init */ |
31 | #include <linux/list.h> | ||
32 | #include <linux/inotify.h> | 30 | #include <linux/inotify.h> |
31 | #include <linux/kernel.h> /* roundup() */ | ||
32 | #include <linux/magic.h> /* superblock magic number */ | ||
33 | #include <linux/mount.h> /* mntget */ | ||
34 | #include <linux/namei.h> /* LOOKUP_FOLLOW */ | ||
35 | #include <linux/path.h> /* struct path */ | ||
36 | #include <linux/sched.h> /* struct user */ | ||
37 | #include <linux/slab.h> /* struct kmem_cache */ | ||
33 | #include <linux/syscalls.h> | 38 | #include <linux/syscalls.h> |
34 | #include <linux/magic.h> | 39 | #include <linux/types.h> |
40 | #include <linux/uaccess.h> | ||
41 | #include <linux/poll.h> | ||
42 | #include <linux/wait.h> | ||
35 | 43 | ||
36 | #include <asm/ioctls.h> | 44 | #include "inotify.h" |
37 | 45 | ||
38 | static struct kmem_cache *watch_cachep __read_mostly; | 46 | #include <asm/ioctls.h> |
39 | static struct kmem_cache *event_cachep __read_mostly; | ||
40 | 47 | ||
41 | static struct vfsmount *inotify_mnt __read_mostly; | 48 | static struct vfsmount *inotify_mnt __read_mostly; |
42 | 49 | ||
50 | /* this just sits here and wastes global memory. used to just pad userspace messages with zeros */ | ||
51 | static struct inotify_event nul_inotify_event; | ||
52 | |||
43 | /* these are configurable via /proc/sys/fs/inotify/ */ | 53 | /* these are configurable via /proc/sys/fs/inotify/ */ |
44 | static int inotify_max_user_instances __read_mostly; | 54 | static int inotify_max_user_instances __read_mostly; |
45 | static int inotify_max_user_watches __read_mostly; | ||
46 | static int inotify_max_queued_events __read_mostly; | 55 | static int inotify_max_queued_events __read_mostly; |
56 | int inotify_max_user_watches __read_mostly; | ||
47 | 57 | ||
48 | /* | 58 | static struct kmem_cache *inotify_inode_mark_cachep __read_mostly; |
49 | * Lock ordering: | 59 | struct kmem_cache *event_priv_cachep __read_mostly; |
50 | * | 60 | static struct fsnotify_event *inotify_ignored_event; |
51 | * inotify_dev->up_mutex (ensures we don't re-add the same watch) | ||
52 | * inode->inotify_mutex (protects inode's watch list) | ||
53 | * inotify_handle->mutex (protects inotify_handle's watch list) | ||
54 | * inotify_dev->ev_mutex (protects device's event queue) | ||
55 | */ | ||
56 | 61 | ||
57 | /* | 62 | /* |
58 | * Lifetimes of the main data structures: | 63 | * When inotify registers a new group it increments this and uses that |
59 | * | 64 | * value as an offset to set the fsnotify group "name" and priority. |
60 | * inotify_device: Lifetime is managed by reference count, from | ||
61 | * sys_inotify_init() until release. Additional references can bump the count | ||
62 | * via get_inotify_dev() and drop the count via put_inotify_dev(). | ||
63 | * | ||
64 | * inotify_user_watch: Lifetime is from create_watch() to the receipt of an | ||
65 | * IN_IGNORED event from inotify, or when using IN_ONESHOT, to receipt of the | ||
66 | * first event, or to inotify_destroy(). | ||
67 | */ | 65 | */ |
68 | 66 | static atomic_t inotify_grp_num; | |
69 | /* | ||
70 | * struct inotify_device - represents an inotify instance | ||
71 | * | ||
72 | * This structure is protected by the mutex 'mutex'. | ||
73 | */ | ||
74 | struct inotify_device { | ||
75 | wait_queue_head_t wq; /* wait queue for i/o */ | ||
76 | struct mutex ev_mutex; /* protects event queue */ | ||
77 | struct mutex up_mutex; /* synchronizes watch updates */ | ||
78 | struct list_head events; /* list of queued events */ | ||
79 | struct user_struct *user; /* user who opened this dev */ | ||
80 | struct inotify_handle *ih; /* inotify handle */ | ||
81 | struct fasync_struct *fa; /* async notification */ | ||
82 | atomic_t count; /* reference count */ | ||
83 | unsigned int queue_size; /* size of the queue (bytes) */ | ||
84 | unsigned int event_count; /* number of pending events */ | ||
85 | unsigned int max_events; /* maximum number of events */ | ||
86 | }; | ||
87 | |||
88 | /* | ||
89 | * struct inotify_kernel_event - An inotify event, originating from a watch and | ||
90 | * queued for user-space. A list of these is attached to each instance of the | ||
91 | * device. In read(), this list is walked and all events that can fit in the | ||
92 | * buffer are returned. | ||
93 | * | ||
94 | * Protected by dev->ev_mutex of the device in which we are queued. | ||
95 | */ | ||
96 | struct inotify_kernel_event { | ||
97 | struct inotify_event event; /* the user-space event */ | ||
98 | struct list_head list; /* entry in inotify_device's list */ | ||
99 | char *name; /* filename, if any */ | ||
100 | }; | ||
101 | |||
102 | /* | ||
103 | * struct inotify_user_watch - our version of an inotify_watch, we add | ||
104 | * a reference to the associated inotify_device. | ||
105 | */ | ||
106 | struct inotify_user_watch { | ||
107 | struct inotify_device *dev; /* associated device */ | ||
108 | struct inotify_watch wdata; /* inotify watch data */ | ||
109 | }; | ||
110 | 67 | ||
111 | #ifdef CONFIG_SYSCTL | 68 | #ifdef CONFIG_SYSCTL |
112 | 69 | ||
@@ -149,280 +106,36 @@ ctl_table inotify_table[] = { | |||
149 | }; | 106 | }; |
150 | #endif /* CONFIG_SYSCTL */ | 107 | #endif /* CONFIG_SYSCTL */ |
151 | 108 | ||
152 | static inline void get_inotify_dev(struct inotify_device *dev) | 109 | static inline __u32 inotify_arg_to_mask(u32 arg) |
153 | { | ||
154 | atomic_inc(&dev->count); | ||
155 | } | ||
156 | |||
157 | static inline void put_inotify_dev(struct inotify_device *dev) | ||
158 | { | ||
159 | if (atomic_dec_and_test(&dev->count)) { | ||
160 | atomic_dec(&dev->user->inotify_devs); | ||
161 | free_uid(dev->user); | ||
162 | kfree(dev); | ||
163 | } | ||
164 | } | ||
165 | |||
166 | /* | ||
167 | * free_inotify_user_watch - cleans up the watch and its references | ||
168 | */ | ||
169 | static void free_inotify_user_watch(struct inotify_watch *w) | ||
170 | { | ||
171 | struct inotify_user_watch *watch; | ||
172 | struct inotify_device *dev; | ||
173 | |||
174 | watch = container_of(w, struct inotify_user_watch, wdata); | ||
175 | dev = watch->dev; | ||
176 | |||
177 | atomic_dec(&dev->user->inotify_watches); | ||
178 | put_inotify_dev(dev); | ||
179 | kmem_cache_free(watch_cachep, watch); | ||
180 | } | ||
181 | |||
182 | /* | ||
183 | * kernel_event - create a new kernel event with the given parameters | ||
184 | * | ||
185 | * This function can sleep. | ||
186 | */ | ||
187 | static struct inotify_kernel_event * kernel_event(s32 wd, u32 mask, u32 cookie, | ||
188 | const char *name) | ||
189 | { | ||
190 | struct inotify_kernel_event *kevent; | ||
191 | |||
192 | kevent = kmem_cache_alloc(event_cachep, GFP_NOFS); | ||
193 | if (unlikely(!kevent)) | ||
194 | return NULL; | ||
195 | |||
196 | /* we hand this out to user-space, so zero it just in case */ | ||
197 | memset(&kevent->event, 0, sizeof(struct inotify_event)); | ||
198 | |||
199 | kevent->event.wd = wd; | ||
200 | kevent->event.mask = mask; | ||
201 | kevent->event.cookie = cookie; | ||
202 | |||
203 | INIT_LIST_HEAD(&kevent->list); | ||
204 | |||
205 | if (name) { | ||
206 | size_t len, rem, event_size = sizeof(struct inotify_event); | ||
207 | |||
208 | /* | ||
209 | * We need to pad the filename so as to properly align an | ||
210 | * array of inotify_event structures. Because the structure is | ||
211 | * small and the common case is a small filename, we just round | ||
212 | * up to the next multiple of the structure's sizeof. This is | ||
213 | * simple and safe for all architectures. | ||
214 | */ | ||
215 | len = strlen(name) + 1; | ||
216 | rem = event_size - len; | ||
217 | if (len > event_size) { | ||
218 | rem = event_size - (len % event_size); | ||
219 | if (len % event_size == 0) | ||
220 | rem = 0; | ||
221 | } | ||
222 | |||
223 | kevent->name = kmalloc(len + rem, GFP_NOFS); | ||
224 | if (unlikely(!kevent->name)) { | ||
225 | kmem_cache_free(event_cachep, kevent); | ||
226 | return NULL; | ||
227 | } | ||
228 | memcpy(kevent->name, name, len); | ||
229 | if (rem) | ||
230 | memset(kevent->name + len, 0, rem); | ||
231 | kevent->event.len = len + rem; | ||
232 | } else { | ||
233 | kevent->event.len = 0; | ||
234 | kevent->name = NULL; | ||
235 | } | ||
236 | |||
237 | return kevent; | ||
238 | } | ||
239 | |||
240 | /* | ||
241 | * inotify_dev_get_event - return the next event in the given dev's queue | ||
242 | * | ||
243 | * Caller must hold dev->ev_mutex. | ||
244 | */ | ||
245 | static inline struct inotify_kernel_event * | ||
246 | inotify_dev_get_event(struct inotify_device *dev) | ||
247 | { | ||
248 | return list_entry(dev->events.next, struct inotify_kernel_event, list); | ||
249 | } | ||
250 | |||
251 | /* | ||
252 | * inotify_dev_get_last_event - return the last event in the given dev's queue | ||
253 | * | ||
254 | * Caller must hold dev->ev_mutex. | ||
255 | */ | ||
256 | static inline struct inotify_kernel_event * | ||
257 | inotify_dev_get_last_event(struct inotify_device *dev) | ||
258 | { | 110 | { |
259 | if (list_empty(&dev->events)) | 111 | __u32 mask; |
260 | return NULL; | ||
261 | return list_entry(dev->events.prev, struct inotify_kernel_event, list); | ||
262 | } | ||
263 | 112 | ||
264 | /* | 113 | /* everything should accept their own ignored and cares about children */ |
265 | * inotify_dev_queue_event - event handler registered with core inotify, adds | 114 | mask = (FS_IN_IGNORED | FS_EVENT_ON_CHILD); |
266 | * a new event to the given device | ||
267 | * | ||
268 | * Can sleep (calls kernel_event()). | ||
269 | */ | ||
270 | static void inotify_dev_queue_event(struct inotify_watch *w, u32 wd, u32 mask, | ||
271 | u32 cookie, const char *name, | ||
272 | struct inode *ignored) | ||
273 | { | ||
274 | struct inotify_user_watch *watch; | ||
275 | struct inotify_device *dev; | ||
276 | struct inotify_kernel_event *kevent, *last; | ||
277 | 115 | ||
278 | watch = container_of(w, struct inotify_user_watch, wdata); | 116 | /* mask off the flags used to open the fd */ |
279 | dev = watch->dev; | 117 | mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT)); |
280 | 118 | ||
281 | mutex_lock(&dev->ev_mutex); | 119 | return mask; |
282 | |||
283 | /* we can safely put the watch as we don't reference it while | ||
284 | * generating the event | ||
285 | */ | ||
286 | if (mask & IN_IGNORED || w->mask & IN_ONESHOT) | ||
287 | put_inotify_watch(w); /* final put */ | ||
288 | |||
289 | /* coalescing: drop this event if it is a dupe of the previous */ | ||
290 | last = inotify_dev_get_last_event(dev); | ||
291 | if (last && last->event.mask == mask && last->event.wd == wd && | ||
292 | last->event.cookie == cookie) { | ||
293 | const char *lastname = last->name; | ||
294 | |||
295 | if (!name && !lastname) | ||
296 | goto out; | ||
297 | if (name && lastname && !strcmp(lastname, name)) | ||
298 | goto out; | ||
299 | } | ||
300 | |||
301 | /* the queue overflowed and we already sent the Q_OVERFLOW event */ | ||
302 | if (unlikely(dev->event_count > dev->max_events)) | ||
303 | goto out; | ||
304 | |||
305 | /* if the queue overflows, we need to notify user space */ | ||
306 | if (unlikely(dev->event_count == dev->max_events)) | ||
307 | kevent = kernel_event(-1, IN_Q_OVERFLOW, cookie, NULL); | ||
308 | else | ||
309 | kevent = kernel_event(wd, mask, cookie, name); | ||
310 | |||
311 | if (unlikely(!kevent)) | ||
312 | goto out; | ||
313 | |||
314 | /* queue the event and wake up anyone waiting */ | ||
315 | dev->event_count++; | ||
316 | dev->queue_size += sizeof(struct inotify_event) + kevent->event.len; | ||
317 | list_add_tail(&kevent->list, &dev->events); | ||
318 | wake_up_interruptible(&dev->wq); | ||
319 | kill_fasync(&dev->fa, SIGIO, POLL_IN); | ||
320 | |||
321 | out: | ||
322 | mutex_unlock(&dev->ev_mutex); | ||
323 | } | ||
324 | |||
325 | /* | ||
326 | * remove_kevent - cleans up the given kevent | ||
327 | * | ||
328 | * Caller must hold dev->ev_mutex. | ||
329 | */ | ||
330 | static void remove_kevent(struct inotify_device *dev, | ||
331 | struct inotify_kernel_event *kevent) | ||
332 | { | ||
333 | list_del(&kevent->list); | ||
334 | |||
335 | dev->event_count--; | ||
336 | dev->queue_size -= sizeof(struct inotify_event) + kevent->event.len; | ||
337 | } | ||
338 | |||
339 | /* | ||
340 | * free_kevent - frees the given kevent. | ||
341 | */ | ||
342 | static void free_kevent(struct inotify_kernel_event *kevent) | ||
343 | { | ||
344 | kfree(kevent->name); | ||
345 | kmem_cache_free(event_cachep, kevent); | ||
346 | } | ||
347 | |||
348 | /* | ||
349 | * inotify_dev_event_dequeue - destroy an event on the given device | ||
350 | * | ||
351 | * Caller must hold dev->ev_mutex. | ||
352 | */ | ||
353 | static void inotify_dev_event_dequeue(struct inotify_device *dev) | ||
354 | { | ||
355 | if (!list_empty(&dev->events)) { | ||
356 | struct inotify_kernel_event *kevent; | ||
357 | kevent = inotify_dev_get_event(dev); | ||
358 | remove_kevent(dev, kevent); | ||
359 | free_kevent(kevent); | ||
360 | } | ||
361 | } | ||
362 | |||
363 | /* | ||
364 | * find_inode - resolve a user-given path to a specific inode | ||
365 | */ | ||
366 | static int find_inode(const char __user *dirname, struct path *path, | ||
367 | unsigned flags) | ||
368 | { | ||
369 | int error; | ||
370 | |||
371 | error = user_path_at(AT_FDCWD, dirname, flags, path); | ||
372 | if (error) | ||
373 | return error; | ||
374 | /* you can only watch an inode if you have read permissions on it */ | ||
375 | error = inode_permission(path->dentry->d_inode, MAY_READ); | ||
376 | if (error) | ||
377 | path_put(path); | ||
378 | return error; | ||
379 | } | 120 | } |
380 | 121 | ||
381 | /* | 122 | static inline u32 inotify_mask_to_arg(__u32 mask) |
382 | * create_watch - creates a watch on the given device. | ||
383 | * | ||
384 | * Callers must hold dev->up_mutex. | ||
385 | */ | ||
386 | static int create_watch(struct inotify_device *dev, struct inode *inode, | ||
387 | u32 mask) | ||
388 | { | 123 | { |
389 | struct inotify_user_watch *watch; | 124 | return mask & (IN_ALL_EVENTS | IN_ISDIR | IN_UNMOUNT | IN_IGNORED | |
390 | int ret; | 125 | IN_Q_OVERFLOW); |
391 | |||
392 | if (atomic_read(&dev->user->inotify_watches) >= | ||
393 | inotify_max_user_watches) | ||
394 | return -ENOSPC; | ||
395 | |||
396 | watch = kmem_cache_alloc(watch_cachep, GFP_KERNEL); | ||
397 | if (unlikely(!watch)) | ||
398 | return -ENOMEM; | ||
399 | |||
400 | /* save a reference to device and bump the count to make it official */ | ||
401 | get_inotify_dev(dev); | ||
402 | watch->dev = dev; | ||
403 | |||
404 | atomic_inc(&dev->user->inotify_watches); | ||
405 | |||
406 | inotify_init_watch(&watch->wdata); | ||
407 | ret = inotify_add_watch(dev->ih, &watch->wdata, inode, mask); | ||
408 | if (ret < 0) | ||
409 | free_inotify_user_watch(&watch->wdata); | ||
410 | |||
411 | return ret; | ||
412 | } | 126 | } |
413 | 127 | ||
414 | /* Device Interface */ | 128 | /* intofiy userspace file descriptor functions */ |
415 | |||
416 | static unsigned int inotify_poll(struct file *file, poll_table *wait) | 129 | static unsigned int inotify_poll(struct file *file, poll_table *wait) |
417 | { | 130 | { |
418 | struct inotify_device *dev = file->private_data; | 131 | struct fsnotify_group *group = file->private_data; |
419 | int ret = 0; | 132 | int ret = 0; |
420 | 133 | ||
421 | poll_wait(file, &dev->wq, wait); | 134 | poll_wait(file, &group->notification_waitq, wait); |
422 | mutex_lock(&dev->ev_mutex); | 135 | mutex_lock(&group->notification_mutex); |
423 | if (!list_empty(&dev->events)) | 136 | if (!fsnotify_notify_queue_is_empty(group)) |
424 | ret = POLLIN | POLLRDNORM; | 137 | ret = POLLIN | POLLRDNORM; |
425 | mutex_unlock(&dev->ev_mutex); | 138 | mutex_unlock(&group->notification_mutex); |
426 | 139 | ||
427 | return ret; | 140 | return ret; |
428 | } | 141 | } |
@@ -432,26 +145,29 @@ static unsigned int inotify_poll(struct file *file, poll_table *wait) | |||
432 | * enough to fit in "count". Return an error pointer if | 145 | * enough to fit in "count". Return an error pointer if |
433 | * not large enough. | 146 | * not large enough. |
434 | * | 147 | * |
435 | * Called with the device ev_mutex held. | 148 | * Called with the group->notification_mutex held. |
436 | */ | 149 | */ |
437 | static struct inotify_kernel_event *get_one_event(struct inotify_device *dev, | 150 | static struct fsnotify_event *get_one_event(struct fsnotify_group *group, |
438 | size_t count) | 151 | size_t count) |
439 | { | 152 | { |
440 | size_t event_size = sizeof(struct inotify_event); | 153 | size_t event_size = sizeof(struct inotify_event); |
441 | struct inotify_kernel_event *kevent; | 154 | struct fsnotify_event *event; |
442 | 155 | ||
443 | if (list_empty(&dev->events)) | 156 | if (fsnotify_notify_queue_is_empty(group)) |
444 | return NULL; | 157 | return NULL; |
445 | 158 | ||
446 | kevent = inotify_dev_get_event(dev); | 159 | event = fsnotify_peek_notify_event(group); |
447 | if (kevent->name) | 160 | |
448 | event_size += kevent->event.len; | 161 | event_size += roundup(event->name_len, event_size); |
449 | 162 | ||
450 | if (event_size > count) | 163 | if (event_size > count) |
451 | return ERR_PTR(-EINVAL); | 164 | return ERR_PTR(-EINVAL); |
452 | 165 | ||
453 | remove_kevent(dev, kevent); | 166 | /* held the notification_mutex the whole time, so this is the |
454 | return kevent; | 167 | * same event we peeked above */ |
168 | fsnotify_remove_notify_event(group); | ||
169 | |||
170 | return event; | ||
455 | } | 171 | } |
456 | 172 | ||
457 | /* | 173 | /* |
@@ -460,51 +176,90 @@ static struct inotify_kernel_event *get_one_event(struct inotify_device *dev, | |||
460 | * We already checked that the event size is smaller than the | 176 | * We already checked that the event size is smaller than the |
461 | * buffer we had in "get_one_event()" above. | 177 | * buffer we had in "get_one_event()" above. |
462 | */ | 178 | */ |
463 | static ssize_t copy_event_to_user(struct inotify_kernel_event *kevent, | 179 | static ssize_t copy_event_to_user(struct fsnotify_group *group, |
180 | struct fsnotify_event *event, | ||
464 | char __user *buf) | 181 | char __user *buf) |
465 | { | 182 | { |
183 | struct inotify_event inotify_event; | ||
184 | struct fsnotify_event_private_data *fsn_priv; | ||
185 | struct inotify_event_private_data *priv; | ||
466 | size_t event_size = sizeof(struct inotify_event); | 186 | size_t event_size = sizeof(struct inotify_event); |
187 | size_t name_len; | ||
188 | |||
189 | /* we get the inotify watch descriptor from the event private data */ | ||
190 | spin_lock(&event->lock); | ||
191 | fsn_priv = fsnotify_remove_priv_from_event(group, event); | ||
192 | spin_unlock(&event->lock); | ||
193 | |||
194 | if (!fsn_priv) | ||
195 | inotify_event.wd = -1; | ||
196 | else { | ||
197 | priv = container_of(fsn_priv, struct inotify_event_private_data, | ||
198 | fsnotify_event_priv_data); | ||
199 | inotify_event.wd = priv->wd; | ||
200 | inotify_free_event_priv(fsn_priv); | ||
201 | } | ||
202 | |||
203 | /* round up event->name_len so it is a multiple of event_size */ | ||
204 | name_len = roundup(event->name_len, event_size); | ||
205 | inotify_event.len = name_len; | ||
206 | |||
207 | inotify_event.mask = inotify_mask_to_arg(event->mask); | ||
208 | inotify_event.cookie = event->sync_cookie; | ||
467 | 209 | ||
468 | if (copy_to_user(buf, &kevent->event, event_size)) | 210 | /* send the main event */ |
211 | if (copy_to_user(buf, &inotify_event, event_size)) | ||
469 | return -EFAULT; | 212 | return -EFAULT; |
470 | 213 | ||
471 | if (kevent->name) { | 214 | buf += event_size; |
472 | buf += event_size; | ||
473 | 215 | ||
474 | if (copy_to_user(buf, kevent->name, kevent->event.len)) | 216 | /* |
217 | * fsnotify only stores the pathname, so here we have to send the pathname | ||
218 | * and then pad that pathname out to a multiple of sizeof(inotify_event) | ||
219 | * with zeros. I get my zeros from the nul_inotify_event. | ||
220 | */ | ||
221 | if (name_len) { | ||
222 | unsigned int len_to_zero = name_len - event->name_len; | ||
223 | /* copy the path name */ | ||
224 | if (copy_to_user(buf, event->file_name, event->name_len)) | ||
475 | return -EFAULT; | 225 | return -EFAULT; |
226 | buf += event->name_len; | ||
476 | 227 | ||
477 | event_size += kevent->event.len; | 228 | /* fill userspace with 0's from nul_inotify_event */ |
229 | if (copy_to_user(buf, &nul_inotify_event, len_to_zero)) | ||
230 | return -EFAULT; | ||
231 | buf += len_to_zero; | ||
232 | event_size += name_len; | ||
478 | } | 233 | } |
234 | |||
479 | return event_size; | 235 | return event_size; |
480 | } | 236 | } |
481 | 237 | ||
482 | static ssize_t inotify_read(struct file *file, char __user *buf, | 238 | static ssize_t inotify_read(struct file *file, char __user *buf, |
483 | size_t count, loff_t *pos) | 239 | size_t count, loff_t *pos) |
484 | { | 240 | { |
485 | struct inotify_device *dev; | 241 | struct fsnotify_group *group; |
242 | struct fsnotify_event *kevent; | ||
486 | char __user *start; | 243 | char __user *start; |
487 | int ret; | 244 | int ret; |
488 | DEFINE_WAIT(wait); | 245 | DEFINE_WAIT(wait); |
489 | 246 | ||
490 | start = buf; | 247 | start = buf; |
491 | dev = file->private_data; | 248 | group = file->private_data; |
492 | 249 | ||
493 | while (1) { | 250 | while (1) { |
494 | struct inotify_kernel_event *kevent; | 251 | prepare_to_wait(&group->notification_waitq, &wait, TASK_INTERRUPTIBLE); |
495 | 252 | ||
496 | prepare_to_wait(&dev->wq, &wait, TASK_INTERRUPTIBLE); | 253 | mutex_lock(&group->notification_mutex); |
497 | 254 | kevent = get_one_event(group, count); | |
498 | mutex_lock(&dev->ev_mutex); | 255 | mutex_unlock(&group->notification_mutex); |
499 | kevent = get_one_event(dev, count); | ||
500 | mutex_unlock(&dev->ev_mutex); | ||
501 | 256 | ||
502 | if (kevent) { | 257 | if (kevent) { |
503 | ret = PTR_ERR(kevent); | 258 | ret = PTR_ERR(kevent); |
504 | if (IS_ERR(kevent)) | 259 | if (IS_ERR(kevent)) |
505 | break; | 260 | break; |
506 | ret = copy_event_to_user(kevent, buf); | 261 | ret = copy_event_to_user(group, kevent, buf); |
507 | free_kevent(kevent); | 262 | fsnotify_put_event(kevent); |
508 | if (ret < 0) | 263 | if (ret < 0) |
509 | break; | 264 | break; |
510 | buf += ret; | 265 | buf += ret; |
@@ -525,7 +280,7 @@ static ssize_t inotify_read(struct file *file, char __user *buf, | |||
525 | schedule(); | 280 | schedule(); |
526 | } | 281 | } |
527 | 282 | ||
528 | finish_wait(&dev->wq, &wait); | 283 | finish_wait(&group->notification_waitq, &wait); |
529 | if (start != buf && ret != -EFAULT) | 284 | if (start != buf && ret != -EFAULT) |
530 | ret = buf - start; | 285 | ret = buf - start; |
531 | return ret; | 286 | return ret; |
@@ -533,25 +288,19 @@ static ssize_t inotify_read(struct file *file, char __user *buf, | |||
533 | 288 | ||
534 | static int inotify_fasync(int fd, struct file *file, int on) | 289 | static int inotify_fasync(int fd, struct file *file, int on) |
535 | { | 290 | { |
536 | struct inotify_device *dev = file->private_data; | 291 | struct fsnotify_group *group = file->private_data; |
537 | 292 | ||
538 | return fasync_helper(fd, file, on, &dev->fa) >= 0 ? 0 : -EIO; | 293 | return fasync_helper(fd, file, on, &group->inotify_data.fa) >= 0 ? 0 : -EIO; |
539 | } | 294 | } |
540 | 295 | ||
541 | static int inotify_release(struct inode *ignored, struct file *file) | 296 | static int inotify_release(struct inode *ignored, struct file *file) |
542 | { | 297 | { |
543 | struct inotify_device *dev = file->private_data; | 298 | struct fsnotify_group *group = file->private_data; |
544 | |||
545 | inotify_destroy(dev->ih); | ||
546 | 299 | ||
547 | /* destroy all of the events on this device */ | 300 | fsnotify_clear_marks_by_group(group); |
548 | mutex_lock(&dev->ev_mutex); | ||
549 | while (!list_empty(&dev->events)) | ||
550 | inotify_dev_event_dequeue(dev); | ||
551 | mutex_unlock(&dev->ev_mutex); | ||
552 | 301 | ||
553 | /* free this device: the put matching the get in inotify_init() */ | 302 | /* free this group, matching get was inotify_init->fsnotify_obtain_group */ |
554 | put_inotify_dev(dev); | 303 | fsnotify_put_group(group); |
555 | 304 | ||
556 | return 0; | 305 | return 0; |
557 | } | 306 | } |
@@ -559,16 +308,27 @@ static int inotify_release(struct inode *ignored, struct file *file) | |||
559 | static long inotify_ioctl(struct file *file, unsigned int cmd, | 308 | static long inotify_ioctl(struct file *file, unsigned int cmd, |
560 | unsigned long arg) | 309 | unsigned long arg) |
561 | { | 310 | { |
562 | struct inotify_device *dev; | 311 | struct fsnotify_group *group; |
312 | struct fsnotify_event_holder *holder; | ||
313 | struct fsnotify_event *event; | ||
563 | void __user *p; | 314 | void __user *p; |
564 | int ret = -ENOTTY; | 315 | int ret = -ENOTTY; |
316 | size_t send_len = 0; | ||
565 | 317 | ||
566 | dev = file->private_data; | 318 | group = file->private_data; |
567 | p = (void __user *) arg; | 319 | p = (void __user *) arg; |
568 | 320 | ||
569 | switch (cmd) { | 321 | switch (cmd) { |
570 | case FIONREAD: | 322 | case FIONREAD: |
571 | ret = put_user(dev->queue_size, (int __user *) p); | 323 | mutex_lock(&group->notification_mutex); |
324 | list_for_each_entry(holder, &group->notification_list, event_list) { | ||
325 | event = holder->event; | ||
326 | send_len += sizeof(struct inotify_event); | ||
327 | send_len += roundup(event->name_len, | ||
328 | sizeof(struct inotify_event)); | ||
329 | } | ||
330 | mutex_unlock(&group->notification_mutex); | ||
331 | ret = put_user(send_len, (int __user *) p); | ||
572 | break; | 332 | break; |
573 | } | 333 | } |
574 | 334 | ||
@@ -576,23 +336,233 @@ static long inotify_ioctl(struct file *file, unsigned int cmd, | |||
576 | } | 336 | } |
577 | 337 | ||
578 | static const struct file_operations inotify_fops = { | 338 | static const struct file_operations inotify_fops = { |
579 | .poll = inotify_poll, | 339 | .poll = inotify_poll, |
580 | .read = inotify_read, | 340 | .read = inotify_read, |
581 | .fasync = inotify_fasync, | 341 | .fasync = inotify_fasync, |
582 | .release = inotify_release, | 342 | .release = inotify_release, |
583 | .unlocked_ioctl = inotify_ioctl, | 343 | .unlocked_ioctl = inotify_ioctl, |
584 | .compat_ioctl = inotify_ioctl, | 344 | .compat_ioctl = inotify_ioctl, |
585 | }; | 345 | }; |
586 | 346 | ||
587 | static const struct inotify_operations inotify_user_ops = { | ||
588 | .handle_event = inotify_dev_queue_event, | ||
589 | .destroy_watch = free_inotify_user_watch, | ||
590 | }; | ||
591 | 347 | ||
348 | /* | ||
349 | * find_inode - resolve a user-given path to a specific inode | ||
350 | */ | ||
351 | static int inotify_find_inode(const char __user *dirname, struct path *path, unsigned flags) | ||
352 | { | ||
353 | int error; | ||
354 | |||
355 | error = user_path_at(AT_FDCWD, dirname, flags, path); | ||
356 | if (error) | ||
357 | return error; | ||
358 | /* you can only watch an inode if you have read permissions on it */ | ||
359 | error = inode_permission(path->dentry->d_inode, MAY_READ); | ||
360 | if (error) | ||
361 | path_put(path); | ||
362 | return error; | ||
363 | } | ||
364 | |||
365 | /* | ||
366 | * When, for whatever reason, inotify is done with a mark (or what used to be a | ||
367 | * watch) we need to remove that watch from the idr and we need to send IN_IGNORED | ||
368 | * for the given wd. | ||
369 | * | ||
370 | * There is a bit of recursion here. The loop looks like: | ||
371 | * inotify_destroy_mark_entry -> fsnotify_destroy_mark_by_entry -> | ||
372 | * inotify_freeing_mark -> inotify_destory_mark_entry -> restart | ||
373 | * But the loop is broken in 2 places. fsnotify_destroy_mark_by_entry sets | ||
374 | * entry->group = NULL before the call to inotify_freeing_mark, so the if (egroup) | ||
375 | * test below will not call back to fsnotify again. But even if that test wasn't | ||
376 | * there this would still be safe since fsnotify_destroy_mark_by_entry() is | ||
377 | * safe from recursion. | ||
378 | */ | ||
379 | void inotify_destroy_mark_entry(struct fsnotify_mark_entry *entry, struct fsnotify_group *group) | ||
380 | { | ||
381 | struct inotify_inode_mark_entry *ientry; | ||
382 | struct inotify_event_private_data *event_priv; | ||
383 | struct fsnotify_event_private_data *fsn_event_priv; | ||
384 | struct fsnotify_group *egroup; | ||
385 | struct idr *idr; | ||
386 | |||
387 | spin_lock(&entry->lock); | ||
388 | egroup = entry->group; | ||
389 | |||
390 | /* if egroup we aren't really done and something might still send events | ||
391 | * for this inode, on the callback we'll send the IN_IGNORED */ | ||
392 | if (egroup) { | ||
393 | spin_unlock(&entry->lock); | ||
394 | fsnotify_destroy_mark_by_entry(entry); | ||
395 | return; | ||
396 | } | ||
397 | spin_unlock(&entry->lock); | ||
398 | |||
399 | ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); | ||
400 | |||
401 | event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL); | ||
402 | if (unlikely(!event_priv)) | ||
403 | goto skip_send_ignore; | ||
404 | |||
405 | fsn_event_priv = &event_priv->fsnotify_event_priv_data; | ||
406 | |||
407 | fsn_event_priv->group = group; | ||
408 | event_priv->wd = ientry->wd; | ||
409 | |||
410 | fsnotify_add_notify_event(group, inotify_ignored_event, fsn_event_priv); | ||
411 | |||
412 | /* did the private data get added? */ | ||
413 | if (list_empty(&fsn_event_priv->event_list)) | ||
414 | inotify_free_event_priv(fsn_event_priv); | ||
415 | |||
416 | skip_send_ignore: | ||
417 | |||
418 | /* remove this entry from the idr */ | ||
419 | spin_lock(&group->inotify_data.idr_lock); | ||
420 | idr = &group->inotify_data.idr; | ||
421 | idr_remove(idr, ientry->wd); | ||
422 | spin_unlock(&group->inotify_data.idr_lock); | ||
423 | |||
424 | /* removed from idr, drop that reference */ | ||
425 | fsnotify_put_mark(entry); | ||
426 | } | ||
427 | |||
428 | /* ding dong the mark is dead */ | ||
429 | static void inotify_free_mark(struct fsnotify_mark_entry *entry) | ||
430 | { | ||
431 | struct inotify_inode_mark_entry *ientry = (struct inotify_inode_mark_entry *)entry; | ||
432 | |||
433 | kmem_cache_free(inotify_inode_mark_cachep, ientry); | ||
434 | } | ||
435 | |||
436 | static int inotify_update_watch(struct fsnotify_group *group, struct inode *inode, u32 arg) | ||
437 | { | ||
438 | struct fsnotify_mark_entry *entry = NULL; | ||
439 | struct inotify_inode_mark_entry *ientry; | ||
440 | int ret = 0; | ||
441 | int add = (arg & IN_MASK_ADD); | ||
442 | __u32 mask; | ||
443 | __u32 old_mask, new_mask; | ||
444 | |||
445 | /* don't allow invalid bits: we don't want flags set */ | ||
446 | mask = inotify_arg_to_mask(arg); | ||
447 | if (unlikely(!mask)) | ||
448 | return -EINVAL; | ||
449 | |||
450 | ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL); | ||
451 | if (unlikely(!ientry)) | ||
452 | return -ENOMEM; | ||
453 | /* we set the mask at the end after attaching it */ | ||
454 | fsnotify_init_mark(&ientry->fsn_entry, inotify_free_mark); | ||
455 | ientry->wd = 0; | ||
456 | |||
457 | find_entry: | ||
458 | spin_lock(&inode->i_lock); | ||
459 | entry = fsnotify_find_mark_entry(group, inode); | ||
460 | spin_unlock(&inode->i_lock); | ||
461 | if (entry) { | ||
462 | kmem_cache_free(inotify_inode_mark_cachep, ientry); | ||
463 | ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); | ||
464 | } else { | ||
465 | if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches) { | ||
466 | ret = -ENOSPC; | ||
467 | goto out_err; | ||
468 | } | ||
469 | |||
470 | ret = fsnotify_add_mark(&ientry->fsn_entry, group, inode); | ||
471 | if (ret == -EEXIST) | ||
472 | goto find_entry; | ||
473 | else if (ret) | ||
474 | goto out_err; | ||
475 | |||
476 | entry = &ientry->fsn_entry; | ||
477 | retry: | ||
478 | ret = -ENOMEM; | ||
479 | if (unlikely(!idr_pre_get(&group->inotify_data.idr, GFP_KERNEL))) | ||
480 | goto out_err; | ||
481 | |||
482 | spin_lock(&group->inotify_data.idr_lock); | ||
483 | /* if entry is added to the idr we keep the reference obtained | ||
484 | * through fsnotify_mark_add. remember to drop this reference | ||
485 | * when entry is removed from idr */ | ||
486 | ret = idr_get_new_above(&group->inotify_data.idr, entry, | ||
487 | ++group->inotify_data.last_wd, | ||
488 | &ientry->wd); | ||
489 | spin_unlock(&group->inotify_data.idr_lock); | ||
490 | if (ret) { | ||
491 | if (ret == -EAGAIN) | ||
492 | goto retry; | ||
493 | goto out_err; | ||
494 | } | ||
495 | atomic_inc(&group->inotify_data.user->inotify_watches); | ||
496 | } | ||
497 | |||
498 | spin_lock(&entry->lock); | ||
499 | |||
500 | old_mask = entry->mask; | ||
501 | if (add) { | ||
502 | entry->mask |= mask; | ||
503 | new_mask = entry->mask; | ||
504 | } else { | ||
505 | entry->mask = mask; | ||
506 | new_mask = entry->mask; | ||
507 | } | ||
508 | |||
509 | spin_unlock(&entry->lock); | ||
510 | |||
511 | if (old_mask != new_mask) { | ||
512 | /* more bits in old than in new? */ | ||
513 | int dropped = (old_mask & ~new_mask); | ||
514 | /* more bits in this entry than the inode's mask? */ | ||
515 | int do_inode = (new_mask & ~inode->i_fsnotify_mask); | ||
516 | /* more bits in this entry than the group? */ | ||
517 | int do_group = (new_mask & ~group->mask); | ||
518 | |||
519 | /* update the inode with this new entry */ | ||
520 | if (dropped || do_inode) | ||
521 | fsnotify_recalc_inode_mask(inode); | ||
522 | |||
523 | /* update the group mask with the new mask */ | ||
524 | if (dropped || do_group) | ||
525 | fsnotify_recalc_group_mask(group); | ||
526 | } | ||
527 | |||
528 | return ientry->wd; | ||
529 | |||
530 | out_err: | ||
531 | /* see this isn't supposed to happen, just kill the watch */ | ||
532 | if (entry) { | ||
533 | fsnotify_destroy_mark_by_entry(entry); | ||
534 | fsnotify_put_mark(entry); | ||
535 | } | ||
536 | return ret; | ||
537 | } | ||
538 | |||
539 | static struct fsnotify_group *inotify_new_group(struct user_struct *user, unsigned int max_events) | ||
540 | { | ||
541 | struct fsnotify_group *group; | ||
542 | unsigned int grp_num; | ||
543 | |||
544 | /* fsnotify_obtain_group took a reference to group, we put this when we kill the file in the end */ | ||
545 | grp_num = (INOTIFY_GROUP_NUM - atomic_inc_return(&inotify_grp_num)); | ||
546 | group = fsnotify_obtain_group(grp_num, 0, &inotify_fsnotify_ops); | ||
547 | if (IS_ERR(group)) | ||
548 | return group; | ||
549 | |||
550 | group->max_events = max_events; | ||
551 | |||
552 | spin_lock_init(&group->inotify_data.idr_lock); | ||
553 | idr_init(&group->inotify_data.idr); | ||
554 | group->inotify_data.last_wd = 0; | ||
555 | group->inotify_data.user = user; | ||
556 | group->inotify_data.fa = NULL; | ||
557 | |||
558 | return group; | ||
559 | } | ||
560 | |||
561 | |||
562 | /* inotify syscalls */ | ||
592 | SYSCALL_DEFINE1(inotify_init1, int, flags) | 563 | SYSCALL_DEFINE1(inotify_init1, int, flags) |
593 | { | 564 | { |
594 | struct inotify_device *dev; | 565 | struct fsnotify_group *group; |
595 | struct inotify_handle *ih; | ||
596 | struct user_struct *user; | 566 | struct user_struct *user; |
597 | struct file *filp; | 567 | struct file *filp; |
598 | int fd, ret; | 568 | int fd, ret; |
@@ -621,45 +591,27 @@ SYSCALL_DEFINE1(inotify_init1, int, flags) | |||
621 | goto out_free_uid; | 591 | goto out_free_uid; |
622 | } | 592 | } |
623 | 593 | ||
624 | dev = kmalloc(sizeof(struct inotify_device), GFP_KERNEL); | 594 | /* fsnotify_obtain_group took a reference to group, we put this when we kill the file in the end */ |
625 | if (unlikely(!dev)) { | 595 | group = inotify_new_group(user, inotify_max_queued_events); |
626 | ret = -ENOMEM; | 596 | if (IS_ERR(group)) { |
597 | ret = PTR_ERR(group); | ||
627 | goto out_free_uid; | 598 | goto out_free_uid; |
628 | } | 599 | } |
629 | 600 | ||
630 | ih = inotify_init(&inotify_user_ops); | ||
631 | if (IS_ERR(ih)) { | ||
632 | ret = PTR_ERR(ih); | ||
633 | goto out_free_dev; | ||
634 | } | ||
635 | dev->ih = ih; | ||
636 | dev->fa = NULL; | ||
637 | |||
638 | filp->f_op = &inotify_fops; | 601 | filp->f_op = &inotify_fops; |
639 | filp->f_path.mnt = mntget(inotify_mnt); | 602 | filp->f_path.mnt = mntget(inotify_mnt); |
640 | filp->f_path.dentry = dget(inotify_mnt->mnt_root); | 603 | filp->f_path.dentry = dget(inotify_mnt->mnt_root); |
641 | filp->f_mapping = filp->f_path.dentry->d_inode->i_mapping; | 604 | filp->f_mapping = filp->f_path.dentry->d_inode->i_mapping; |
642 | filp->f_mode = FMODE_READ; | 605 | filp->f_mode = FMODE_READ; |
643 | filp->f_flags = O_RDONLY | (flags & O_NONBLOCK); | 606 | filp->f_flags = O_RDONLY | (flags & O_NONBLOCK); |
644 | filp->private_data = dev; | 607 | filp->private_data = group; |
645 | 608 | ||
646 | INIT_LIST_HEAD(&dev->events); | ||
647 | init_waitqueue_head(&dev->wq); | ||
648 | mutex_init(&dev->ev_mutex); | ||
649 | mutex_init(&dev->up_mutex); | ||
650 | dev->event_count = 0; | ||
651 | dev->queue_size = 0; | ||
652 | dev->max_events = inotify_max_queued_events; | ||
653 | dev->user = user; | ||
654 | atomic_set(&dev->count, 0); | ||
655 | |||
656 | get_inotify_dev(dev); | ||
657 | atomic_inc(&user->inotify_devs); | 609 | atomic_inc(&user->inotify_devs); |
610 | |||
658 | fd_install(fd, filp); | 611 | fd_install(fd, filp); |
659 | 612 | ||
660 | return fd; | 613 | return fd; |
661 | out_free_dev: | 614 | |
662 | kfree(dev); | ||
663 | out_free_uid: | 615 | out_free_uid: |
664 | free_uid(user); | 616 | free_uid(user); |
665 | put_filp(filp); | 617 | put_filp(filp); |
@@ -676,8 +628,8 @@ SYSCALL_DEFINE0(inotify_init) | |||
676 | SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname, | 628 | SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname, |
677 | u32, mask) | 629 | u32, mask) |
678 | { | 630 | { |
631 | struct fsnotify_group *group; | ||
679 | struct inode *inode; | 632 | struct inode *inode; |
680 | struct inotify_device *dev; | ||
681 | struct path path; | 633 | struct path path; |
682 | struct file *filp; | 634 | struct file *filp; |
683 | int ret, fput_needed; | 635 | int ret, fput_needed; |
@@ -698,20 +650,20 @@ SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname, | |||
698 | if (mask & IN_ONLYDIR) | 650 | if (mask & IN_ONLYDIR) |
699 | flags |= LOOKUP_DIRECTORY; | 651 | flags |= LOOKUP_DIRECTORY; |
700 | 652 | ||
701 | ret = find_inode(pathname, &path, flags); | 653 | ret = inotify_find_inode(pathname, &path, flags); |
702 | if (unlikely(ret)) | 654 | if (ret) |
703 | goto fput_and_out; | 655 | goto fput_and_out; |
704 | 656 | ||
705 | /* inode held in place by reference to path; dev by fget on fd */ | 657 | /* inode held in place by reference to path; group by fget on fd */ |
706 | inode = path.dentry->d_inode; | 658 | inode = path.dentry->d_inode; |
707 | dev = filp->private_data; | 659 | group = filp->private_data; |
708 | 660 | ||
709 | mutex_lock(&dev->up_mutex); | 661 | /* create/update an inode mark */ |
710 | ret = inotify_find_update_watch(dev->ih, inode, mask); | 662 | ret = inotify_update_watch(group, inode, mask); |
711 | if (ret == -ENOENT) | 663 | if (unlikely(ret)) |
712 | ret = create_watch(dev, inode, mask); | 664 | goto path_put_and_out; |
713 | mutex_unlock(&dev->up_mutex); | ||
714 | 665 | ||
666 | path_put_and_out: | ||
715 | path_put(&path); | 667 | path_put(&path); |
716 | fput_and_out: | 668 | fput_and_out: |
717 | fput_light(filp, fput_needed); | 669 | fput_light(filp, fput_needed); |
@@ -720,9 +672,10 @@ fput_and_out: | |||
720 | 672 | ||
721 | SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd) | 673 | SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd) |
722 | { | 674 | { |
675 | struct fsnotify_group *group; | ||
676 | struct fsnotify_mark_entry *entry; | ||
723 | struct file *filp; | 677 | struct file *filp; |
724 | struct inotify_device *dev; | 678 | int ret = 0, fput_needed; |
725 | int ret, fput_needed; | ||
726 | 679 | ||
727 | filp = fget_light(fd, &fput_needed); | 680 | filp = fget_light(fd, &fput_needed); |
728 | if (unlikely(!filp)) | 681 | if (unlikely(!filp)) |
@@ -734,10 +687,20 @@ SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd) | |||
734 | goto out; | 687 | goto out; |
735 | } | 688 | } |
736 | 689 | ||
737 | dev = filp->private_data; | 690 | group = filp->private_data; |
738 | 691 | ||
739 | /* we free our watch data when we get IN_IGNORED */ | 692 | spin_lock(&group->inotify_data.idr_lock); |
740 | ret = inotify_rm_wd(dev->ih, wd); | 693 | entry = idr_find(&group->inotify_data.idr, wd); |
694 | if (unlikely(!entry)) { | ||
695 | spin_unlock(&group->inotify_data.idr_lock); | ||
696 | ret = -EINVAL; | ||
697 | goto out; | ||
698 | } | ||
699 | fsnotify_get_mark(entry); | ||
700 | spin_unlock(&group->inotify_data.idr_lock); | ||
701 | |||
702 | inotify_destroy_mark_entry(entry, group); | ||
703 | fsnotify_put_mark(entry); | ||
741 | 704 | ||
742 | out: | 705 | out: |
743 | fput_light(filp, fput_needed); | 706 | fput_light(filp, fput_needed); |
@@ -753,9 +716,9 @@ inotify_get_sb(struct file_system_type *fs_type, int flags, | |||
753 | } | 716 | } |
754 | 717 | ||
755 | static struct file_system_type inotify_fs_type = { | 718 | static struct file_system_type inotify_fs_type = { |
756 | .name = "inotifyfs", | 719 | .name = "inotifyfs", |
757 | .get_sb = inotify_get_sb, | 720 | .get_sb = inotify_get_sb, |
758 | .kill_sb = kill_anon_super, | 721 | .kill_sb = kill_anon_super, |
759 | }; | 722 | }; |
760 | 723 | ||
761 | /* | 724 | /* |
@@ -775,18 +738,16 @@ static int __init inotify_user_setup(void) | |||
775 | if (IS_ERR(inotify_mnt)) | 738 | if (IS_ERR(inotify_mnt)) |
776 | panic("inotify: kern_mount ret %ld!\n", PTR_ERR(inotify_mnt)); | 739 | panic("inotify: kern_mount ret %ld!\n", PTR_ERR(inotify_mnt)); |
777 | 740 | ||
741 | inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark_entry, SLAB_PANIC); | ||
742 | event_priv_cachep = KMEM_CACHE(inotify_event_private_data, SLAB_PANIC); | ||
743 | inotify_ignored_event = fsnotify_create_event(NULL, FS_IN_IGNORED, NULL, FSNOTIFY_EVENT_NONE, NULL, 0); | ||
744 | if (!inotify_ignored_event) | ||
745 | panic("unable to allocate the inotify ignored event\n"); | ||
746 | |||
778 | inotify_max_queued_events = 16384; | 747 | inotify_max_queued_events = 16384; |
779 | inotify_max_user_instances = 128; | 748 | inotify_max_user_instances = 128; |
780 | inotify_max_user_watches = 8192; | 749 | inotify_max_user_watches = 8192; |
781 | 750 | ||
782 | watch_cachep = kmem_cache_create("inotify_watch_cache", | ||
783 | sizeof(struct inotify_user_watch), | ||
784 | 0, SLAB_PANIC, NULL); | ||
785 | event_cachep = kmem_cache_create("inotify_event_cache", | ||
786 | sizeof(struct inotify_kernel_event), | ||
787 | 0, SLAB_PANIC, NULL); | ||
788 | |||
789 | return 0; | 751 | return 0; |
790 | } | 752 | } |
791 | |||
792 | module_init(inotify_user_setup); | 753 | module_init(inotify_user_setup); |
diff --git a/fs/notify/notification.c b/fs/notify/notification.c new file mode 100644 index 000000000000..959b73e756fd --- /dev/null +++ b/fs/notify/notification.c | |||
@@ -0,0 +1,411 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com> | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or modify | ||
5 | * it under the terms of the GNU General Public License as published by | ||
6 | * the Free Software Foundation; either version 2, or (at your option) | ||
7 | * any later version. | ||
8 | * | ||
9 | * This program is distributed in the hope that it will be useful, | ||
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
12 | * GNU General Public License for more details. | ||
13 | * | ||
14 | * You should have received a copy of the GNU General Public License | ||
15 | * along with this program; see the file COPYING. If not, write to | ||
16 | * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | ||
17 | */ | ||
18 | |||
19 | /* | ||
20 | * Basic idea behind the notification queue: An fsnotify group (like inotify) | ||
21 | * sends the userspace notification about events asyncronously some time after | ||
22 | * the event happened. When inotify gets an event it will need to add that | ||
23 | * event to the group notify queue. Since a single event might need to be on | ||
24 | * multiple group's notification queues we can't add the event directly to each | ||
25 | * queue and instead add a small "event_holder" to each queue. This event_holder | ||
26 | * has a pointer back to the original event. Since the majority of events are | ||
27 | * going to end up on one, and only one, notification queue we embed one | ||
28 | * event_holder into each event. This means we have a single allocation instead | ||
29 | * of always needing two. If the embedded event_holder is already in use by | ||
30 | * another group a new event_holder (from fsnotify_event_holder_cachep) will be | ||
31 | * allocated and used. | ||
32 | */ | ||
33 | |||
34 | #include <linux/fs.h> | ||
35 | #include <linux/init.h> | ||
36 | #include <linux/kernel.h> | ||
37 | #include <linux/list.h> | ||
38 | #include <linux/module.h> | ||
39 | #include <linux/mount.h> | ||
40 | #include <linux/mutex.h> | ||
41 | #include <linux/namei.h> | ||
42 | #include <linux/path.h> | ||
43 | #include <linux/slab.h> | ||
44 | #include <linux/spinlock.h> | ||
45 | |||
46 | #include <asm/atomic.h> | ||
47 | |||
48 | #include <linux/fsnotify_backend.h> | ||
49 | #include "fsnotify.h" | ||
50 | |||
51 | static struct kmem_cache *fsnotify_event_cachep; | ||
52 | static struct kmem_cache *fsnotify_event_holder_cachep; | ||
53 | /* | ||
54 | * This is a magic event we send when the q is too full. Since it doesn't | ||
55 | * hold real event information we just keep one system wide and use it any time | ||
56 | * it is needed. It's refcnt is set 1 at kernel init time and will never | ||
57 | * get set to 0 so it will never get 'freed' | ||
58 | */ | ||
59 | static struct fsnotify_event q_overflow_event; | ||
60 | static atomic_t fsnotify_sync_cookie = ATOMIC_INIT(0); | ||
61 | |||
62 | /** | ||
63 | * fsnotify_get_cookie - return a unique cookie for use in synchronizing events. | ||
64 | * Called from fsnotify_move, which is inlined into filesystem modules. | ||
65 | */ | ||
66 | u32 fsnotify_get_cookie(void) | ||
67 | { | ||
68 | return atomic_inc_return(&fsnotify_sync_cookie); | ||
69 | } | ||
70 | EXPORT_SYMBOL_GPL(fsnotify_get_cookie); | ||
71 | |||
72 | /* return true if the notify queue is empty, false otherwise */ | ||
73 | bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group) | ||
74 | { | ||
75 | BUG_ON(!mutex_is_locked(&group->notification_mutex)); | ||
76 | return list_empty(&group->notification_list) ? true : false; | ||
77 | } | ||
78 | |||
79 | void fsnotify_get_event(struct fsnotify_event *event) | ||
80 | { | ||
81 | atomic_inc(&event->refcnt); | ||
82 | } | ||
83 | |||
84 | void fsnotify_put_event(struct fsnotify_event *event) | ||
85 | { | ||
86 | if (!event) | ||
87 | return; | ||
88 | |||
89 | if (atomic_dec_and_test(&event->refcnt)) { | ||
90 | if (event->data_type == FSNOTIFY_EVENT_PATH) | ||
91 | path_put(&event->path); | ||
92 | |||
93 | BUG_ON(!list_empty(&event->private_data_list)); | ||
94 | |||
95 | kfree(event->file_name); | ||
96 | kmem_cache_free(fsnotify_event_cachep, event); | ||
97 | } | ||
98 | } | ||
99 | |||
100 | struct fsnotify_event_holder *fsnotify_alloc_event_holder(void) | ||
101 | { | ||
102 | return kmem_cache_alloc(fsnotify_event_holder_cachep, GFP_KERNEL); | ||
103 | } | ||
104 | |||
105 | void fsnotify_destroy_event_holder(struct fsnotify_event_holder *holder) | ||
106 | { | ||
107 | kmem_cache_free(fsnotify_event_holder_cachep, holder); | ||
108 | } | ||
109 | |||
110 | /* | ||
111 | * Find the private data that the group previously attached to this event when | ||
112 | * the group added the event to the notification queue (fsnotify_add_notify_event) | ||
113 | */ | ||
114 | struct fsnotify_event_private_data *fsnotify_remove_priv_from_event(struct fsnotify_group *group, struct fsnotify_event *event) | ||
115 | { | ||
116 | struct fsnotify_event_private_data *lpriv; | ||
117 | struct fsnotify_event_private_data *priv = NULL; | ||
118 | |||
119 | assert_spin_locked(&event->lock); | ||
120 | |||
121 | list_for_each_entry(lpriv, &event->private_data_list, event_list) { | ||
122 | if (lpriv->group == group) { | ||
123 | priv = lpriv; | ||
124 | list_del(&priv->event_list); | ||
125 | break; | ||
126 | } | ||
127 | } | ||
128 | return priv; | ||
129 | } | ||
130 | |||
131 | /* | ||
132 | * Check if 2 events contain the same information. We do not compare private data | ||
133 | * but at this moment that isn't a problem for any know fsnotify listeners. | ||
134 | */ | ||
135 | static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new) | ||
136 | { | ||
137 | if ((old->mask == new->mask) && | ||
138 | (old->to_tell == new->to_tell) && | ||
139 | (old->data_type == new->data_type)) { | ||
140 | switch (old->data_type) { | ||
141 | case (FSNOTIFY_EVENT_INODE): | ||
142 | if (old->inode == new->inode) | ||
143 | return true; | ||
144 | break; | ||
145 | case (FSNOTIFY_EVENT_PATH): | ||
146 | if ((old->path.mnt == new->path.mnt) && | ||
147 | (old->path.dentry == new->path.dentry)) | ||
148 | return true; | ||
149 | case (FSNOTIFY_EVENT_NONE): | ||
150 | return true; | ||
151 | }; | ||
152 | } | ||
153 | return false; | ||
154 | } | ||
155 | |||
156 | /* | ||
157 | * Add an event to the group notification queue. The group can later pull this | ||
158 | * event off the queue to deal with. If the event is successfully added to the | ||
159 | * group's notification queue, a reference is taken on event. | ||
160 | */ | ||
161 | int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event, | ||
162 | struct fsnotify_event_private_data *priv) | ||
163 | { | ||
164 | struct fsnotify_event_holder *holder = NULL; | ||
165 | struct list_head *list = &group->notification_list; | ||
166 | struct fsnotify_event_holder *last_holder; | ||
167 | struct fsnotify_event *last_event; | ||
168 | |||
169 | /* easy to tell if priv was attached to the event */ | ||
170 | INIT_LIST_HEAD(&priv->event_list); | ||
171 | |||
172 | /* | ||
173 | * There is one fsnotify_event_holder embedded inside each fsnotify_event. | ||
174 | * Check if we expect to be able to use that holder. If not alloc a new | ||
175 | * holder. | ||
176 | * For the overflow event it's possible that something will use the in | ||
177 | * event holder before we get the lock so we may need to jump back and | ||
178 | * alloc a new holder, this can't happen for most events... | ||
179 | */ | ||
180 | if (!list_empty(&event->holder.event_list)) { | ||
181 | alloc_holder: | ||
182 | holder = fsnotify_alloc_event_holder(); | ||
183 | if (!holder) | ||
184 | return -ENOMEM; | ||
185 | } | ||
186 | |||
187 | mutex_lock(&group->notification_mutex); | ||
188 | |||
189 | if (group->q_len >= group->max_events) { | ||
190 | event = &q_overflow_event; | ||
191 | /* sorry, no private data on the overflow event */ | ||
192 | priv = NULL; | ||
193 | } | ||
194 | |||
195 | spin_lock(&event->lock); | ||
196 | |||
197 | if (list_empty(&event->holder.event_list)) { | ||
198 | if (unlikely(holder)) | ||
199 | fsnotify_destroy_event_holder(holder); | ||
200 | holder = &event->holder; | ||
201 | } else if (unlikely(!holder)) { | ||
202 | /* between the time we checked above and got the lock the in | ||
203 | * event holder was used, go back and get a new one */ | ||
204 | spin_unlock(&event->lock); | ||
205 | mutex_unlock(&group->notification_mutex); | ||
206 | goto alloc_holder; | ||
207 | } | ||
208 | |||
209 | if (!list_empty(list)) { | ||
210 | last_holder = list_entry(list->prev, struct fsnotify_event_holder, event_list); | ||
211 | last_event = last_holder->event; | ||
212 | if (event_compare(last_event, event)) { | ||
213 | spin_unlock(&event->lock); | ||
214 | mutex_unlock(&group->notification_mutex); | ||
215 | if (holder != &event->holder) | ||
216 | fsnotify_destroy_event_holder(holder); | ||
217 | return -EEXIST; | ||
218 | } | ||
219 | } | ||
220 | |||
221 | group->q_len++; | ||
222 | holder->event = event; | ||
223 | |||
224 | fsnotify_get_event(event); | ||
225 | list_add_tail(&holder->event_list, list); | ||
226 | if (priv) | ||
227 | list_add_tail(&priv->event_list, &event->private_data_list); | ||
228 | spin_unlock(&event->lock); | ||
229 | mutex_unlock(&group->notification_mutex); | ||
230 | |||
231 | wake_up(&group->notification_waitq); | ||
232 | return 0; | ||
233 | } | ||
234 | |||
235 | /* | ||
236 | * Remove and return the first event from the notification list. There is a | ||
237 | * reference held on this event since it was on the list. It is the responsibility | ||
238 | * of the caller to drop this reference. | ||
239 | */ | ||
240 | struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group) | ||
241 | { | ||
242 | struct fsnotify_event *event; | ||
243 | struct fsnotify_event_holder *holder; | ||
244 | |||
245 | BUG_ON(!mutex_is_locked(&group->notification_mutex)); | ||
246 | |||
247 | holder = list_first_entry(&group->notification_list, struct fsnotify_event_holder, event_list); | ||
248 | |||
249 | event = holder->event; | ||
250 | |||
251 | spin_lock(&event->lock); | ||
252 | holder->event = NULL; | ||
253 | list_del_init(&holder->event_list); | ||
254 | spin_unlock(&event->lock); | ||
255 | |||
256 | /* event == holder means we are referenced through the in event holder */ | ||
257 | if (holder != &event->holder) | ||
258 | fsnotify_destroy_event_holder(holder); | ||
259 | |||
260 | group->q_len--; | ||
261 | |||
262 | return event; | ||
263 | } | ||
264 | |||
265 | /* | ||
266 | * This will not remove the event, that must be done with fsnotify_remove_notify_event() | ||
267 | */ | ||
268 | struct fsnotify_event *fsnotify_peek_notify_event(struct fsnotify_group *group) | ||
269 | { | ||
270 | struct fsnotify_event *event; | ||
271 | struct fsnotify_event_holder *holder; | ||
272 | |||
273 | BUG_ON(!mutex_is_locked(&group->notification_mutex)); | ||
274 | |||
275 | holder = list_first_entry(&group->notification_list, struct fsnotify_event_holder, event_list); | ||
276 | event = holder->event; | ||
277 | |||
278 | return event; | ||
279 | } | ||
280 | |||
281 | /* | ||
282 | * Called when a group is being torn down to clean up any outstanding | ||
283 | * event notifications. | ||
284 | */ | ||
285 | void fsnotify_flush_notify(struct fsnotify_group *group) | ||
286 | { | ||
287 | struct fsnotify_event *event; | ||
288 | struct fsnotify_event_private_data *priv; | ||
289 | |||
290 | mutex_lock(&group->notification_mutex); | ||
291 | while (!fsnotify_notify_queue_is_empty(group)) { | ||
292 | event = fsnotify_remove_notify_event(group); | ||
293 | /* if they don't implement free_event_priv they better not have attached any */ | ||
294 | if (group->ops->free_event_priv) { | ||
295 | spin_lock(&event->lock); | ||
296 | priv = fsnotify_remove_priv_from_event(group, event); | ||
297 | spin_unlock(&event->lock); | ||
298 | if (priv) | ||
299 | group->ops->free_event_priv(priv); | ||
300 | } | ||
301 | fsnotify_put_event(event); /* matches fsnotify_add_notify_event */ | ||
302 | } | ||
303 | mutex_unlock(&group->notification_mutex); | ||
304 | } | ||
305 | |||
306 | static void initialize_event(struct fsnotify_event *event) | ||
307 | { | ||
308 | event->holder.event = NULL; | ||
309 | INIT_LIST_HEAD(&event->holder.event_list); | ||
310 | atomic_set(&event->refcnt, 1); | ||
311 | |||
312 | spin_lock_init(&event->lock); | ||
313 | |||
314 | event->path.dentry = NULL; | ||
315 | event->path.mnt = NULL; | ||
316 | event->inode = NULL; | ||
317 | event->data_type = FSNOTIFY_EVENT_NONE; | ||
318 | |||
319 | INIT_LIST_HEAD(&event->private_data_list); | ||
320 | |||
321 | event->to_tell = NULL; | ||
322 | |||
323 | event->file_name = NULL; | ||
324 | event->name_len = 0; | ||
325 | |||
326 | event->sync_cookie = 0; | ||
327 | } | ||
328 | |||
329 | /* | ||
330 | * fsnotify_create_event - Allocate a new event which will be sent to each | ||
331 | * group's handle_event function if the group was interested in this | ||
332 | * particular event. | ||
333 | * | ||
334 | * @to_tell the inode which is supposed to receive the event (sometimes a | ||
335 | * parent of the inode to which the event happened. | ||
336 | * @mask what actually happened. | ||
337 | * @data pointer to the object which was actually affected | ||
338 | * @data_type flag indication if the data is a file, path, inode, nothing... | ||
339 | * @name the filename, if available | ||
340 | */ | ||
341 | struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, void *data, | ||
342 | int data_type, const char *name, u32 cookie) | ||
343 | { | ||
344 | struct fsnotify_event *event; | ||
345 | |||
346 | event = kmem_cache_alloc(fsnotify_event_cachep, GFP_KERNEL); | ||
347 | if (!event) | ||
348 | return NULL; | ||
349 | |||
350 | initialize_event(event); | ||
351 | |||
352 | if (name) { | ||
353 | event->file_name = kstrdup(name, GFP_KERNEL); | ||
354 | if (!event->file_name) { | ||
355 | kmem_cache_free(fsnotify_event_cachep, event); | ||
356 | return NULL; | ||
357 | } | ||
358 | event->name_len = strlen(event->file_name); | ||
359 | } | ||
360 | |||
361 | event->sync_cookie = cookie; | ||
362 | event->to_tell = to_tell; | ||
363 | |||
364 | switch (data_type) { | ||
365 | case FSNOTIFY_EVENT_FILE: { | ||
366 | struct file *file = data; | ||
367 | struct path *path = &file->f_path; | ||
368 | event->path.dentry = path->dentry; | ||
369 | event->path.mnt = path->mnt; | ||
370 | path_get(&event->path); | ||
371 | event->data_type = FSNOTIFY_EVENT_PATH; | ||
372 | break; | ||
373 | } | ||
374 | case FSNOTIFY_EVENT_PATH: { | ||
375 | struct path *path = data; | ||
376 | event->path.dentry = path->dentry; | ||
377 | event->path.mnt = path->mnt; | ||
378 | path_get(&event->path); | ||
379 | event->data_type = FSNOTIFY_EVENT_PATH; | ||
380 | break; | ||
381 | } | ||
382 | case FSNOTIFY_EVENT_INODE: | ||
383 | event->inode = data; | ||
384 | event->data_type = FSNOTIFY_EVENT_INODE; | ||
385 | break; | ||
386 | case FSNOTIFY_EVENT_NONE: | ||
387 | event->inode = NULL; | ||
388 | event->path.dentry = NULL; | ||
389 | event->path.mnt = NULL; | ||
390 | break; | ||
391 | default: | ||
392 | BUG(); | ||
393 | } | ||
394 | |||
395 | event->mask = mask; | ||
396 | |||
397 | return event; | ||
398 | } | ||
399 | |||
400 | __init int fsnotify_notification_init(void) | ||
401 | { | ||
402 | fsnotify_event_cachep = KMEM_CACHE(fsnotify_event, SLAB_PANIC); | ||
403 | fsnotify_event_holder_cachep = KMEM_CACHE(fsnotify_event_holder, SLAB_PANIC); | ||
404 | |||
405 | initialize_event(&q_overflow_event); | ||
406 | q_overflow_event.mask = FS_Q_OVERFLOW; | ||
407 | |||
408 | return 0; | ||
409 | } | ||
410 | subsys_initcall(fsnotify_notification_init); | ||
411 | |||
diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 15156364d196..97978004338d 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h | |||
@@ -180,10 +180,12 @@ d_iput: no no no yes | |||
180 | #define DCACHE_REFERENCED 0x0008 /* Recently used, don't discard. */ | 180 | #define DCACHE_REFERENCED 0x0008 /* Recently used, don't discard. */ |
181 | #define DCACHE_UNHASHED 0x0010 | 181 | #define DCACHE_UNHASHED 0x0010 |
182 | 182 | ||
183 | #define DCACHE_INOTIFY_PARENT_WATCHED 0x0020 /* Parent inode is watched */ | 183 | #define DCACHE_INOTIFY_PARENT_WATCHED 0x0020 /* Parent inode is watched by inotify */ |
184 | 184 | ||
185 | #define DCACHE_COOKIE 0x0040 /* For use by dcookie subsystem */ | 185 | #define DCACHE_COOKIE 0x0040 /* For use by dcookie subsystem */ |
186 | 186 | ||
187 | #define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080 /* Parent inode is watched by some fsnotify listener */ | ||
188 | |||
187 | extern spinlock_t dcache_lock; | 189 | extern spinlock_t dcache_lock; |
188 | extern seqlock_t rename_lock; | 190 | extern seqlock_t rename_lock; |
189 | 191 | ||
diff --git a/include/linux/dnotify.h b/include/linux/dnotify.h index 102a902b4396..ecc06286226d 100644 --- a/include/linux/dnotify.h +++ b/include/linux/dnotify.h | |||
@@ -10,7 +10,7 @@ | |||
10 | 10 | ||
11 | struct dnotify_struct { | 11 | struct dnotify_struct { |
12 | struct dnotify_struct * dn_next; | 12 | struct dnotify_struct * dn_next; |
13 | unsigned long dn_mask; | 13 | __u32 dn_mask; |
14 | int dn_fd; | 14 | int dn_fd; |
15 | struct file * dn_filp; | 15 | struct file * dn_filp; |
16 | fl_owner_t dn_owner; | 16 | fl_owner_t dn_owner; |
@@ -21,23 +21,18 @@ struct dnotify_struct { | |||
21 | 21 | ||
22 | #ifdef CONFIG_DNOTIFY | 22 | #ifdef CONFIG_DNOTIFY |
23 | 23 | ||
24 | extern void __inode_dir_notify(struct inode *, unsigned long); | 24 | #define DNOTIFY_ALL_EVENTS (FS_DELETE | FS_DELETE_CHILD |\ |
25 | FS_MODIFY | FS_MODIFY_CHILD |\ | ||
26 | FS_ACCESS | FS_ACCESS_CHILD |\ | ||
27 | FS_ATTRIB | FS_ATTRIB_CHILD |\ | ||
28 | FS_CREATE | FS_DN_RENAME |\ | ||
29 | FS_MOVED_FROM | FS_MOVED_TO) | ||
30 | |||
25 | extern void dnotify_flush(struct file *, fl_owner_t); | 31 | extern void dnotify_flush(struct file *, fl_owner_t); |
26 | extern int fcntl_dirnotify(int, struct file *, unsigned long); | 32 | extern int fcntl_dirnotify(int, struct file *, unsigned long); |
27 | extern void dnotify_parent(struct dentry *, unsigned long); | ||
28 | |||
29 | static inline void inode_dir_notify(struct inode *inode, unsigned long event) | ||
30 | { | ||
31 | if (inode->i_dnotify_mask & (event)) | ||
32 | __inode_dir_notify(inode, event); | ||
33 | } | ||
34 | 33 | ||
35 | #else | 34 | #else |
36 | 35 | ||
37 | static inline void __inode_dir_notify(struct inode *inode, unsigned long event) | ||
38 | { | ||
39 | } | ||
40 | |||
41 | static inline void dnotify_flush(struct file *filp, fl_owner_t id) | 36 | static inline void dnotify_flush(struct file *filp, fl_owner_t id) |
42 | { | 37 | { |
43 | } | 38 | } |
@@ -47,14 +42,6 @@ static inline int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) | |||
47 | return -EINVAL; | 42 | return -EINVAL; |
48 | } | 43 | } |
49 | 44 | ||
50 | static inline void dnotify_parent(struct dentry *dentry, unsigned long event) | ||
51 | { | ||
52 | } | ||
53 | |||
54 | static inline void inode_dir_notify(struct inode *inode, unsigned long event) | ||
55 | { | ||
56 | } | ||
57 | |||
58 | #endif /* CONFIG_DNOTIFY */ | 45 | #endif /* CONFIG_DNOTIFY */ |
59 | 46 | ||
60 | #endif /* __KERNEL __ */ | 47 | #endif /* __KERNEL __ */ |
diff --git a/include/linux/fs.h b/include/linux/fs.h index 83d6b4397245..323b5ce474c1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h | |||
@@ -755,9 +755,9 @@ struct inode { | |||
755 | 755 | ||
756 | __u32 i_generation; | 756 | __u32 i_generation; |
757 | 757 | ||
758 | #ifdef CONFIG_DNOTIFY | 758 | #ifdef CONFIG_FSNOTIFY |
759 | unsigned long i_dnotify_mask; /* Directory notify events */ | 759 | __u32 i_fsnotify_mask; /* all events this inode cares about */ |
760 | struct dnotify_struct *i_dnotify; /* for directory notifications */ | 760 | struct hlist_head i_fsnotify_mark_entries; /* fsnotify mark entries */ |
761 | #endif | 761 | #endif |
762 | 762 | ||
763 | #ifdef CONFIG_INOTIFY | 763 | #ifdef CONFIG_INOTIFY |
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index 00fbd5b245c9..936f9aa8bb97 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h | |||
@@ -13,6 +13,7 @@ | |||
13 | 13 | ||
14 | #include <linux/dnotify.h> | 14 | #include <linux/dnotify.h> |
15 | #include <linux/inotify.h> | 15 | #include <linux/inotify.h> |
16 | #include <linux/fsnotify_backend.h> | ||
16 | #include <linux/audit.h> | 17 | #include <linux/audit.h> |
17 | 18 | ||
18 | /* | 19 | /* |
@@ -22,19 +23,45 @@ | |||
22 | static inline void fsnotify_d_instantiate(struct dentry *entry, | 23 | static inline void fsnotify_d_instantiate(struct dentry *entry, |
23 | struct inode *inode) | 24 | struct inode *inode) |
24 | { | 25 | { |
26 | __fsnotify_d_instantiate(entry, inode); | ||
27 | |||
25 | inotify_d_instantiate(entry, inode); | 28 | inotify_d_instantiate(entry, inode); |
26 | } | 29 | } |
27 | 30 | ||
31 | /* Notify this dentry's parent about a child's events. */ | ||
32 | static inline void fsnotify_parent(struct dentry *dentry, __u32 mask) | ||
33 | { | ||
34 | __fsnotify_parent(dentry, mask); | ||
35 | |||
36 | inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); | ||
37 | } | ||
38 | |||
28 | /* | 39 | /* |
29 | * fsnotify_d_move - entry has been moved | 40 | * fsnotify_d_move - entry has been moved |
30 | * Called with dcache_lock and entry->d_lock held. | 41 | * Called with dcache_lock and entry->d_lock held. |
31 | */ | 42 | */ |
32 | static inline void fsnotify_d_move(struct dentry *entry) | 43 | static inline void fsnotify_d_move(struct dentry *entry) |
33 | { | 44 | { |
45 | /* | ||
46 | * On move we need to update entry->d_flags to indicate if the new parent | ||
47 | * cares about events from this entry. | ||
48 | */ | ||
49 | __fsnotify_update_dcache_flags(entry); | ||
50 | |||
34 | inotify_d_move(entry); | 51 | inotify_d_move(entry); |
35 | } | 52 | } |
36 | 53 | ||
37 | /* | 54 | /* |
55 | * fsnotify_link_count - inode's link count changed | ||
56 | */ | ||
57 | static inline void fsnotify_link_count(struct inode *inode) | ||
58 | { | ||
59 | inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL); | ||
60 | |||
61 | fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0); | ||
62 | } | ||
63 | |||
64 | /* | ||
38 | * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir | 65 | * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir |
39 | */ | 66 | */ |
40 | static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, | 67 | static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, |
@@ -42,42 +69,62 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, | |||
42 | int isdir, struct inode *target, struct dentry *moved) | 69 | int isdir, struct inode *target, struct dentry *moved) |
43 | { | 70 | { |
44 | struct inode *source = moved->d_inode; | 71 | struct inode *source = moved->d_inode; |
45 | u32 cookie = inotify_get_cookie(); | 72 | u32 in_cookie = inotify_get_cookie(); |
73 | u32 fs_cookie = fsnotify_get_cookie(); | ||
74 | __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM); | ||
75 | __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO); | ||
46 | 76 | ||
47 | if (old_dir == new_dir) | 77 | if (old_dir == new_dir) |
48 | inode_dir_notify(old_dir, DN_RENAME); | 78 | old_dir_mask |= FS_DN_RENAME; |
49 | else { | ||
50 | inode_dir_notify(old_dir, DN_DELETE); | ||
51 | inode_dir_notify(new_dir, DN_CREATE); | ||
52 | } | ||
53 | 79 | ||
54 | if (isdir) | 80 | if (isdir) { |
55 | isdir = IN_ISDIR; | 81 | isdir = IN_ISDIR; |
56 | inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir,cookie,old_name, | 82 | old_dir_mask |= FS_IN_ISDIR; |
83 | new_dir_mask |= FS_IN_ISDIR; | ||
84 | } | ||
85 | |||
86 | inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir, in_cookie, old_name, | ||
57 | source); | 87 | source); |
58 | inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name, | 88 | inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, in_cookie, new_name, |
59 | source); | 89 | source); |
60 | 90 | ||
91 | fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name, fs_cookie); | ||
92 | fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name, fs_cookie); | ||
93 | |||
61 | if (target) { | 94 | if (target) { |
62 | inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL, NULL); | 95 | inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL, NULL); |
63 | inotify_inode_is_dead(target); | 96 | inotify_inode_is_dead(target); |
97 | |||
98 | /* this is really a link_count change not a removal */ | ||
99 | fsnotify_link_count(target); | ||
64 | } | 100 | } |
65 | 101 | ||
66 | if (source) { | 102 | if (source) { |
67 | inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL); | 103 | inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL); |
104 | fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0); | ||
68 | } | 105 | } |
69 | audit_inode_child(new_name, moved, new_dir); | 106 | audit_inode_child(new_name, moved, new_dir); |
70 | } | 107 | } |
71 | 108 | ||
72 | /* | 109 | /* |
110 | * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed | ||
111 | */ | ||
112 | static inline void fsnotify_inode_delete(struct inode *inode) | ||
113 | { | ||
114 | __fsnotify_inode_delete(inode); | ||
115 | } | ||
116 | |||
117 | /* | ||
73 | * fsnotify_nameremove - a filename was removed from a directory | 118 | * fsnotify_nameremove - a filename was removed from a directory |
74 | */ | 119 | */ |
75 | static inline void fsnotify_nameremove(struct dentry *dentry, int isdir) | 120 | static inline void fsnotify_nameremove(struct dentry *dentry, int isdir) |
76 | { | 121 | { |
122 | __u32 mask = FS_DELETE; | ||
123 | |||
77 | if (isdir) | 124 | if (isdir) |
78 | isdir = IN_ISDIR; | 125 | mask |= FS_IN_ISDIR; |
79 | dnotify_parent(dentry, DN_DELETE); | 126 | |
80 | inotify_dentry_parent_queue_event(dentry, IN_DELETE|isdir, 0, dentry->d_name.name); | 127 | fsnotify_parent(dentry, mask); |
81 | } | 128 | } |
82 | 129 | ||
83 | /* | 130 | /* |
@@ -87,14 +134,9 @@ static inline void fsnotify_inoderemove(struct inode *inode) | |||
87 | { | 134 | { |
88 | inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL, NULL); | 135 | inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL, NULL); |
89 | inotify_inode_is_dead(inode); | 136 | inotify_inode_is_dead(inode); |
90 | } | ||
91 | 137 | ||
92 | /* | 138 | fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0); |
93 | * fsnotify_link_count - inode's link count changed | 139 | __fsnotify_inode_delete(inode); |
94 | */ | ||
95 | static inline void fsnotify_link_count(struct inode *inode) | ||
96 | { | ||
97 | inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL); | ||
98 | } | 140 | } |
99 | 141 | ||
100 | /* | 142 | /* |
@@ -102,10 +144,11 @@ static inline void fsnotify_link_count(struct inode *inode) | |||
102 | */ | 144 | */ |
103 | static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) | 145 | static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) |
104 | { | 146 | { |
105 | inode_dir_notify(inode, DN_CREATE); | ||
106 | inotify_inode_queue_event(inode, IN_CREATE, 0, dentry->d_name.name, | 147 | inotify_inode_queue_event(inode, IN_CREATE, 0, dentry->d_name.name, |
107 | dentry->d_inode); | 148 | dentry->d_inode); |
108 | audit_inode_child(dentry->d_name.name, dentry, inode); | 149 | audit_inode_child(dentry->d_name.name, dentry, inode); |
150 | |||
151 | fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0); | ||
109 | } | 152 | } |
110 | 153 | ||
111 | /* | 154 | /* |
@@ -115,11 +158,12 @@ static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) | |||
115 | */ | 158 | */ |
116 | static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry) | 159 | static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry) |
117 | { | 160 | { |
118 | inode_dir_notify(dir, DN_CREATE); | ||
119 | inotify_inode_queue_event(dir, IN_CREATE, 0, new_dentry->d_name.name, | 161 | inotify_inode_queue_event(dir, IN_CREATE, 0, new_dentry->d_name.name, |
120 | inode); | 162 | inode); |
121 | fsnotify_link_count(inode); | 163 | fsnotify_link_count(inode); |
122 | audit_inode_child(new_dentry->d_name.name, new_dentry, dir); | 164 | audit_inode_child(new_dentry->d_name.name, new_dentry, dir); |
165 | |||
166 | fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0); | ||
123 | } | 167 | } |
124 | 168 | ||
125 | /* | 169 | /* |
@@ -127,10 +171,13 @@ static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct | |||
127 | */ | 171 | */ |
128 | static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) | 172 | static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) |
129 | { | 173 | { |
130 | inode_dir_notify(inode, DN_CREATE); | 174 | __u32 mask = (FS_CREATE | FS_IN_ISDIR); |
131 | inotify_inode_queue_event(inode, IN_CREATE | IN_ISDIR, 0, | 175 | struct inode *d_inode = dentry->d_inode; |
132 | dentry->d_name.name, dentry->d_inode); | 176 | |
177 | inotify_inode_queue_event(inode, mask, 0, dentry->d_name.name, d_inode); | ||
133 | audit_inode_child(dentry->d_name.name, dentry, inode); | 178 | audit_inode_child(dentry->d_name.name, dentry, inode); |
179 | |||
180 | fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0); | ||
134 | } | 181 | } |
135 | 182 | ||
136 | /* | 183 | /* |
@@ -139,14 +186,15 @@ static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) | |||
139 | static inline void fsnotify_access(struct dentry *dentry) | 186 | static inline void fsnotify_access(struct dentry *dentry) |
140 | { | 187 | { |
141 | struct inode *inode = dentry->d_inode; | 188 | struct inode *inode = dentry->d_inode; |
142 | u32 mask = IN_ACCESS; | 189 | __u32 mask = FS_ACCESS; |
143 | 190 | ||
144 | if (S_ISDIR(inode->i_mode)) | 191 | if (S_ISDIR(inode->i_mode)) |
145 | mask |= IN_ISDIR; | 192 | mask |= FS_IN_ISDIR; |
146 | 193 | ||
147 | dnotify_parent(dentry, DN_ACCESS); | ||
148 | inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); | ||
149 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); | 194 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); |
195 | |||
196 | fsnotify_parent(dentry, mask); | ||
197 | fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); | ||
150 | } | 198 | } |
151 | 199 | ||
152 | /* | 200 | /* |
@@ -155,14 +203,15 @@ static inline void fsnotify_access(struct dentry *dentry) | |||
155 | static inline void fsnotify_modify(struct dentry *dentry) | 203 | static inline void fsnotify_modify(struct dentry *dentry) |
156 | { | 204 | { |
157 | struct inode *inode = dentry->d_inode; | 205 | struct inode *inode = dentry->d_inode; |
158 | u32 mask = IN_MODIFY; | 206 | __u32 mask = FS_MODIFY; |
159 | 207 | ||
160 | if (S_ISDIR(inode->i_mode)) | 208 | if (S_ISDIR(inode->i_mode)) |
161 | mask |= IN_ISDIR; | 209 | mask |= FS_IN_ISDIR; |
162 | 210 | ||
163 | dnotify_parent(dentry, DN_MODIFY); | ||
164 | inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); | ||
165 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); | 211 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); |
212 | |||
213 | fsnotify_parent(dentry, mask); | ||
214 | fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); | ||
166 | } | 215 | } |
167 | 216 | ||
168 | /* | 217 | /* |
@@ -171,13 +220,15 @@ static inline void fsnotify_modify(struct dentry *dentry) | |||
171 | static inline void fsnotify_open(struct dentry *dentry) | 220 | static inline void fsnotify_open(struct dentry *dentry) |
172 | { | 221 | { |
173 | struct inode *inode = dentry->d_inode; | 222 | struct inode *inode = dentry->d_inode; |
174 | u32 mask = IN_OPEN; | 223 | __u32 mask = FS_OPEN; |
175 | 224 | ||
176 | if (S_ISDIR(inode->i_mode)) | 225 | if (S_ISDIR(inode->i_mode)) |
177 | mask |= IN_ISDIR; | 226 | mask |= FS_IN_ISDIR; |
178 | 227 | ||
179 | inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); | ||
180 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); | 228 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); |
229 | |||
230 | fsnotify_parent(dentry, mask); | ||
231 | fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); | ||
181 | } | 232 | } |
182 | 233 | ||
183 | /* | 234 | /* |
@@ -187,15 +238,16 @@ static inline void fsnotify_close(struct file *file) | |||
187 | { | 238 | { |
188 | struct dentry *dentry = file->f_path.dentry; | 239 | struct dentry *dentry = file->f_path.dentry; |
189 | struct inode *inode = dentry->d_inode; | 240 | struct inode *inode = dentry->d_inode; |
190 | const char *name = dentry->d_name.name; | ||
191 | fmode_t mode = file->f_mode; | 241 | fmode_t mode = file->f_mode; |
192 | u32 mask = (mode & FMODE_WRITE) ? IN_CLOSE_WRITE : IN_CLOSE_NOWRITE; | 242 | __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE; |
193 | 243 | ||
194 | if (S_ISDIR(inode->i_mode)) | 244 | if (S_ISDIR(inode->i_mode)) |
195 | mask |= IN_ISDIR; | 245 | mask |= FS_IN_ISDIR; |
196 | 246 | ||
197 | inotify_dentry_parent_queue_event(dentry, mask, 0, name); | ||
198 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); | 247 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); |
248 | |||
249 | fsnotify_parent(dentry, mask); | ||
250 | fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0); | ||
199 | } | 251 | } |
200 | 252 | ||
201 | /* | 253 | /* |
@@ -204,13 +256,15 @@ static inline void fsnotify_close(struct file *file) | |||
204 | static inline void fsnotify_xattr(struct dentry *dentry) | 256 | static inline void fsnotify_xattr(struct dentry *dentry) |
205 | { | 257 | { |
206 | struct inode *inode = dentry->d_inode; | 258 | struct inode *inode = dentry->d_inode; |
207 | u32 mask = IN_ATTRIB; | 259 | __u32 mask = FS_ATTRIB; |
208 | 260 | ||
209 | if (S_ISDIR(inode->i_mode)) | 261 | if (S_ISDIR(inode->i_mode)) |
210 | mask |= IN_ISDIR; | 262 | mask |= FS_IN_ISDIR; |
211 | 263 | ||
212 | inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); | ||
213 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); | 264 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); |
265 | |||
266 | fsnotify_parent(dentry, mask); | ||
267 | fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); | ||
214 | } | 268 | } |
215 | 269 | ||
216 | /* | 270 | /* |
@@ -220,50 +274,37 @@ static inline void fsnotify_xattr(struct dentry *dentry) | |||
220 | static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) | 274 | static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) |
221 | { | 275 | { |
222 | struct inode *inode = dentry->d_inode; | 276 | struct inode *inode = dentry->d_inode; |
223 | int dn_mask = 0; | 277 | __u32 mask = 0; |
224 | u32 in_mask = 0; | 278 | |
279 | if (ia_valid & ATTR_UID) | ||
280 | mask |= FS_ATTRIB; | ||
281 | if (ia_valid & ATTR_GID) | ||
282 | mask |= FS_ATTRIB; | ||
283 | if (ia_valid & ATTR_SIZE) | ||
284 | mask |= FS_MODIFY; | ||
225 | 285 | ||
226 | if (ia_valid & ATTR_UID) { | ||
227 | in_mask |= IN_ATTRIB; | ||
228 | dn_mask |= DN_ATTRIB; | ||
229 | } | ||
230 | if (ia_valid & ATTR_GID) { | ||
231 | in_mask |= IN_ATTRIB; | ||
232 | dn_mask |= DN_ATTRIB; | ||
233 | } | ||
234 | if (ia_valid & ATTR_SIZE) { | ||
235 | in_mask |= IN_MODIFY; | ||
236 | dn_mask |= DN_MODIFY; | ||
237 | } | ||
238 | /* both times implies a utime(s) call */ | 286 | /* both times implies a utime(s) call */ |
239 | if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) | 287 | if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) |
240 | { | 288 | mask |= FS_ATTRIB; |
241 | in_mask |= IN_ATTRIB; | 289 | else if (ia_valid & ATTR_ATIME) |
242 | dn_mask |= DN_ATTRIB; | 290 | mask |= FS_ACCESS; |
243 | } else if (ia_valid & ATTR_ATIME) { | 291 | else if (ia_valid & ATTR_MTIME) |
244 | in_mask |= IN_ACCESS; | 292 | mask |= FS_MODIFY; |
245 | dn_mask |= DN_ACCESS; | 293 | |
246 | } else if (ia_valid & ATTR_MTIME) { | 294 | if (ia_valid & ATTR_MODE) |
247 | in_mask |= IN_MODIFY; | 295 | mask |= FS_ATTRIB; |
248 | dn_mask |= DN_MODIFY; | ||
249 | } | ||
250 | if (ia_valid & ATTR_MODE) { | ||
251 | in_mask |= IN_ATTRIB; | ||
252 | dn_mask |= DN_ATTRIB; | ||
253 | } | ||
254 | 296 | ||
255 | if (dn_mask) | 297 | if (mask) { |
256 | dnotify_parent(dentry, dn_mask); | ||
257 | if (in_mask) { | ||
258 | if (S_ISDIR(inode->i_mode)) | 298 | if (S_ISDIR(inode->i_mode)) |
259 | in_mask |= IN_ISDIR; | 299 | mask |= FS_IN_ISDIR; |
260 | inotify_inode_queue_event(inode, in_mask, 0, NULL, NULL); | 300 | inotify_inode_queue_event(inode, mask, 0, NULL, NULL); |
261 | inotify_dentry_parent_queue_event(dentry, in_mask, 0, | 301 | |
262 | dentry->d_name.name); | 302 | fsnotify_parent(dentry, mask); |
303 | fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); | ||
263 | } | 304 | } |
264 | } | 305 | } |
265 | 306 | ||
266 | #ifdef CONFIG_INOTIFY /* inotify helpers */ | 307 | #if defined(CONFIG_INOTIFY) || defined(CONFIG_FSNOTIFY) /* notify helpers */ |
267 | 308 | ||
268 | /* | 309 | /* |
269 | * fsnotify_oldname_init - save off the old filename before we change it | 310 | * fsnotify_oldname_init - save off the old filename before we change it |
@@ -281,7 +322,7 @@ static inline void fsnotify_oldname_free(const char *old_name) | |||
281 | kfree(old_name); | 322 | kfree(old_name); |
282 | } | 323 | } |
283 | 324 | ||
284 | #else /* CONFIG_INOTIFY */ | 325 | #else /* CONFIG_INOTIFY || CONFIG_FSNOTIFY */ |
285 | 326 | ||
286 | static inline const char *fsnotify_oldname_init(const char *name) | 327 | static inline const char *fsnotify_oldname_init(const char *name) |
287 | { | 328 | { |
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h new file mode 100644 index 000000000000..44848aa830dc --- /dev/null +++ b/include/linux/fsnotify_backend.h | |||
@@ -0,0 +1,387 @@ | |||
1 | /* | ||
2 | * Filesystem access notification for Linux | ||
3 | * | ||
4 | * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com> | ||
5 | */ | ||
6 | |||
7 | #ifndef __LINUX_FSNOTIFY_BACKEND_H | ||
8 | #define __LINUX_FSNOTIFY_BACKEND_H | ||
9 | |||
10 | #ifdef __KERNEL__ | ||
11 | |||
12 | #include <linux/idr.h> /* inotify uses this */ | ||
13 | #include <linux/fs.h> /* struct inode */ | ||
14 | #include <linux/list.h> | ||
15 | #include <linux/path.h> /* struct path */ | ||
16 | #include <linux/spinlock.h> | ||
17 | #include <linux/types.h> | ||
18 | |||
19 | #include <asm/atomic.h> | ||
20 | |||
21 | /* | ||
22 | * IN_* from inotfy.h lines up EXACTLY with FS_*, this is so we can easily | ||
23 | * convert between them. dnotify only needs conversion at watch creation | ||
24 | * so no perf loss there. fanotify isn't defined yet, so it can use the | ||
25 | * wholes if it needs more events. | ||
26 | */ | ||
27 | #define FS_ACCESS 0x00000001 /* File was accessed */ | ||
28 | #define FS_MODIFY 0x00000002 /* File was modified */ | ||
29 | #define FS_ATTRIB 0x00000004 /* Metadata changed */ | ||
30 | #define FS_CLOSE_WRITE 0x00000008 /* Writtable file was closed */ | ||
31 | #define FS_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */ | ||
32 | #define FS_OPEN 0x00000020 /* File was opened */ | ||
33 | #define FS_MOVED_FROM 0x00000040 /* File was moved from X */ | ||
34 | #define FS_MOVED_TO 0x00000080 /* File was moved to Y */ | ||
35 | #define FS_CREATE 0x00000100 /* Subfile was created */ | ||
36 | #define FS_DELETE 0x00000200 /* Subfile was deleted */ | ||
37 | #define FS_DELETE_SELF 0x00000400 /* Self was deleted */ | ||
38 | #define FS_MOVE_SELF 0x00000800 /* Self was moved */ | ||
39 | |||
40 | #define FS_UNMOUNT 0x00002000 /* inode on umount fs */ | ||
41 | #define FS_Q_OVERFLOW 0x00004000 /* Event queued overflowed */ | ||
42 | #define FS_IN_IGNORED 0x00008000 /* last inotify event here */ | ||
43 | |||
44 | #define FS_IN_ISDIR 0x40000000 /* event occurred against dir */ | ||
45 | #define FS_IN_ONESHOT 0x80000000 /* only send event once */ | ||
46 | |||
47 | #define FS_DN_RENAME 0x10000000 /* file renamed */ | ||
48 | #define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */ | ||
49 | |||
50 | /* This inode cares about things that happen to its children. Always set for | ||
51 | * dnotify and inotify. */ | ||
52 | #define FS_EVENT_ON_CHILD 0x08000000 | ||
53 | |||
54 | /* This is a list of all events that may get sent to a parernt based on fs event | ||
55 | * happening to inodes inside that directory */ | ||
56 | #define FS_EVENTS_POSS_ON_CHILD (FS_ACCESS | FS_MODIFY | FS_ATTRIB |\ | ||
57 | FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | FS_OPEN |\ | ||
58 | FS_MOVED_FROM | FS_MOVED_TO | FS_CREATE |\ | ||
59 | FS_DELETE) | ||
60 | |||
61 | /* listeners that hard code group numbers near the top */ | ||
62 | #define DNOTIFY_GROUP_NUM UINT_MAX | ||
63 | #define INOTIFY_GROUP_NUM (DNOTIFY_GROUP_NUM-1) | ||
64 | |||
65 | struct fsnotify_group; | ||
66 | struct fsnotify_event; | ||
67 | struct fsnotify_mark_entry; | ||
68 | struct fsnotify_event_private_data; | ||
69 | |||
70 | /* | ||
71 | * Each group much define these ops. The fsnotify infrastructure will call | ||
72 | * these operations for each relevant group. | ||
73 | * | ||
74 | * should_send_event - given a group, inode, and mask this function determines | ||
75 | * if the group is interested in this event. | ||
76 | * handle_event - main call for a group to handle an fs event | ||
77 | * free_group_priv - called when a group refcnt hits 0 to clean up the private union | ||
78 | * freeing-mark - this means that a mark has been flagged to die when everything | ||
79 | * finishes using it. The function is supplied with what must be a | ||
80 | * valid group and inode to use to clean up. | ||
81 | */ | ||
82 | struct fsnotify_ops { | ||
83 | bool (*should_send_event)(struct fsnotify_group *group, struct inode *inode, __u32 mask); | ||
84 | int (*handle_event)(struct fsnotify_group *group, struct fsnotify_event *event); | ||
85 | void (*free_group_priv)(struct fsnotify_group *group); | ||
86 | void (*freeing_mark)(struct fsnotify_mark_entry *entry, struct fsnotify_group *group); | ||
87 | void (*free_event_priv)(struct fsnotify_event_private_data *priv); | ||
88 | }; | ||
89 | |||
90 | /* | ||
91 | * A group is a "thing" that wants to receive notification about filesystem | ||
92 | * events. The mask holds the subset of event types this group cares about. | ||
93 | * refcnt on a group is up to the implementor and at any moment if it goes 0 | ||
94 | * everything will be cleaned up. | ||
95 | */ | ||
96 | struct fsnotify_group { | ||
97 | /* | ||
98 | * global list of all groups receiving events from fsnotify. | ||
99 | * anchored by fsnotify_groups and protected by either fsnotify_grp_mutex | ||
100 | * or fsnotify_grp_srcu depending on write vs read. | ||
101 | */ | ||
102 | struct list_head group_list; | ||
103 | |||
104 | /* | ||
105 | * Defines all of the event types in which this group is interested. | ||
106 | * This mask is a bitwise OR of the FS_* events from above. Each time | ||
107 | * this mask changes for a group (if it changes) the correct functions | ||
108 | * must be called to update the global structures which indicate global | ||
109 | * interest in event types. | ||
110 | */ | ||
111 | __u32 mask; | ||
112 | |||
113 | /* | ||
114 | * How the refcnt is used is up to each group. When the refcnt hits 0 | ||
115 | * fsnotify will clean up all of the resources associated with this group. | ||
116 | * As an example, the dnotify group will always have a refcnt=1 and that | ||
117 | * will never change. Inotify, on the other hand, has a group per | ||
118 | * inotify_init() and the refcnt will hit 0 only when that fd has been | ||
119 | * closed. | ||
120 | */ | ||
121 | atomic_t refcnt; /* things with interest in this group */ | ||
122 | unsigned int group_num; /* simply prevents accidental group collision */ | ||
123 | |||
124 | const struct fsnotify_ops *ops; /* how this group handles things */ | ||
125 | |||
126 | /* needed to send notification to userspace */ | ||
127 | struct mutex notification_mutex; /* protect the notification_list */ | ||
128 | struct list_head notification_list; /* list of event_holder this group needs to send to userspace */ | ||
129 | wait_queue_head_t notification_waitq; /* read() on the notification file blocks on this waitq */ | ||
130 | unsigned int q_len; /* events on the queue */ | ||
131 | unsigned int max_events; /* maximum events allowed on the list */ | ||
132 | |||
133 | /* stores all fastapth entries assoc with this group so they can be cleaned on unregister */ | ||
134 | spinlock_t mark_lock; /* protect mark_entries list */ | ||
135 | atomic_t num_marks; /* 1 for each mark entry and 1 for not being | ||
136 | * past the point of no return when freeing | ||
137 | * a group */ | ||
138 | struct list_head mark_entries; /* all inode mark entries for this group */ | ||
139 | |||
140 | /* prevents double list_del of group_list. protected by global fsnotify_grp_mutex */ | ||
141 | bool on_group_list; | ||
142 | |||
143 | /* groups can define private fields here or use the void *private */ | ||
144 | union { | ||
145 | void *private; | ||
146 | #ifdef CONFIG_INOTIFY_USER | ||
147 | struct inotify_group_private_data { | ||
148 | spinlock_t idr_lock; | ||
149 | struct idr idr; | ||
150 | u32 last_wd; | ||
151 | struct fasync_struct *fa; /* async notification */ | ||
152 | struct user_struct *user; | ||
153 | } inotify_data; | ||
154 | #endif | ||
155 | }; | ||
156 | }; | ||
157 | |||
158 | /* | ||
159 | * A single event can be queued in multiple group->notification_lists. | ||
160 | * | ||
161 | * each group->notification_list will point to an event_holder which in turns points | ||
162 | * to the actual event that needs to be sent to userspace. | ||
163 | * | ||
164 | * Seemed cheaper to create a refcnt'd event and a small holder for every group | ||
165 | * than create a different event for every group | ||
166 | * | ||
167 | */ | ||
168 | struct fsnotify_event_holder { | ||
169 | struct fsnotify_event *event; | ||
170 | struct list_head event_list; | ||
171 | }; | ||
172 | |||
173 | /* | ||
174 | * Inotify needs to tack data onto an event. This struct lets us later find the | ||
175 | * correct private data of the correct group. | ||
176 | */ | ||
177 | struct fsnotify_event_private_data { | ||
178 | struct fsnotify_group *group; | ||
179 | struct list_head event_list; | ||
180 | }; | ||
181 | |||
182 | /* | ||
183 | * all of the information about the original object we want to now send to | ||
184 | * a group. If you want to carry more info from the accessing task to the | ||
185 | * listener this structure is where you need to be adding fields. | ||
186 | */ | ||
187 | struct fsnotify_event { | ||
188 | /* | ||
189 | * If we create an event we are also likely going to need a holder | ||
190 | * to link to a group. So embed one holder in the event. Means only | ||
191 | * one allocation for the common case where we only have one group | ||
192 | */ | ||
193 | struct fsnotify_event_holder holder; | ||
194 | spinlock_t lock; /* protection for the associated event_holder and private_list */ | ||
195 | /* to_tell may ONLY be dereferenced during handle_event(). */ | ||
196 | struct inode *to_tell; /* either the inode the event happened to or its parent */ | ||
197 | /* | ||
198 | * depending on the event type we should have either a path or inode | ||
199 | * We hold a reference on path, but NOT on inode. Since we have the ref on | ||
200 | * the path, it may be dereferenced at any point during this object's | ||
201 | * lifetime. That reference is dropped when this object's refcnt hits | ||
202 | * 0. If this event contains an inode instead of a path, the inode may | ||
203 | * ONLY be used during handle_event(). | ||
204 | */ | ||
205 | union { | ||
206 | struct path path; | ||
207 | struct inode *inode; | ||
208 | }; | ||
209 | /* when calling fsnotify tell it if the data is a path or inode */ | ||
210 | #define FSNOTIFY_EVENT_NONE 0 | ||
211 | #define FSNOTIFY_EVENT_PATH 1 | ||
212 | #define FSNOTIFY_EVENT_INODE 2 | ||
213 | #define FSNOTIFY_EVENT_FILE 3 | ||
214 | int data_type; /* which of the above union we have */ | ||
215 | atomic_t refcnt; /* how many groups still are using/need to send this event */ | ||
216 | __u32 mask; /* the type of access, bitwise OR for FS_* event types */ | ||
217 | |||
218 | u32 sync_cookie; /* used to corrolate events, namely inotify mv events */ | ||
219 | char *file_name; | ||
220 | size_t name_len; | ||
221 | |||
222 | struct list_head private_data_list; /* groups can store private data here */ | ||
223 | }; | ||
224 | |||
225 | /* | ||
226 | * a mark is simply an entry attached to an in core inode which allows an | ||
227 | * fsnotify listener to indicate they are either no longer interested in events | ||
228 | * of a type matching mask or only interested in those events. | ||
229 | * | ||
230 | * these are flushed when an inode is evicted from core and may be flushed | ||
231 | * when the inode is modified (as seen by fsnotify_access). Some fsnotify users | ||
232 | * (such as dnotify) will flush these when the open fd is closed and not at | ||
233 | * inode eviction or modification. | ||
234 | */ | ||
235 | struct fsnotify_mark_entry { | ||
236 | __u32 mask; /* mask this mark entry is for */ | ||
237 | /* we hold ref for each i_list and g_list. also one ref for each 'thing' | ||
238 | * in kernel that found and may be using this mark. */ | ||
239 | atomic_t refcnt; /* active things looking at this mark */ | ||
240 | struct inode *inode; /* inode this entry is associated with */ | ||
241 | struct fsnotify_group *group; /* group this mark entry is for */ | ||
242 | struct hlist_node i_list; /* list of mark_entries by inode->i_fsnotify_mark_entries */ | ||
243 | struct list_head g_list; /* list of mark_entries by group->i_fsnotify_mark_entries */ | ||
244 | spinlock_t lock; /* protect group, inode, and killme */ | ||
245 | struct list_head free_i_list; /* tmp list used when freeing this mark */ | ||
246 | struct list_head free_g_list; /* tmp list used when freeing this mark */ | ||
247 | void (*free_mark)(struct fsnotify_mark_entry *entry); /* called on final put+free */ | ||
248 | }; | ||
249 | |||
250 | #ifdef CONFIG_FSNOTIFY | ||
251 | |||
252 | /* called from the vfs helpers */ | ||
253 | |||
254 | /* main fsnotify call to send events */ | ||
255 | extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, | ||
256 | const char *name, u32 cookie); | ||
257 | extern void __fsnotify_parent(struct dentry *dentry, __u32 mask); | ||
258 | extern void __fsnotify_inode_delete(struct inode *inode); | ||
259 | extern u32 fsnotify_get_cookie(void); | ||
260 | |||
261 | static inline int fsnotify_inode_watches_children(struct inode *inode) | ||
262 | { | ||
263 | /* FS_EVENT_ON_CHILD is set if the inode may care */ | ||
264 | if (!(inode->i_fsnotify_mask & FS_EVENT_ON_CHILD)) | ||
265 | return 0; | ||
266 | /* this inode might care about child events, does it care about the | ||
267 | * specific set of events that can happen on a child? */ | ||
268 | return inode->i_fsnotify_mask & FS_EVENTS_POSS_ON_CHILD; | ||
269 | } | ||
270 | |||
271 | /* | ||
272 | * Update the dentry with a flag indicating the interest of its parent to receive | ||
273 | * filesystem events when those events happens to this dentry->d_inode. | ||
274 | */ | ||
275 | static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) | ||
276 | { | ||
277 | struct dentry *parent; | ||
278 | |||
279 | assert_spin_locked(&dcache_lock); | ||
280 | assert_spin_locked(&dentry->d_lock); | ||
281 | |||
282 | parent = dentry->d_parent; | ||
283 | if (fsnotify_inode_watches_children(parent->d_inode)) | ||
284 | dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; | ||
285 | else | ||
286 | dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; | ||
287 | } | ||
288 | |||
289 | /* | ||
290 | * fsnotify_d_instantiate - instantiate a dentry for inode | ||
291 | * Called with dcache_lock held. | ||
292 | */ | ||
293 | static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) | ||
294 | { | ||
295 | if (!inode) | ||
296 | return; | ||
297 | |||
298 | assert_spin_locked(&dcache_lock); | ||
299 | |||
300 | spin_lock(&dentry->d_lock); | ||
301 | __fsnotify_update_dcache_flags(dentry); | ||
302 | spin_unlock(&dentry->d_lock); | ||
303 | } | ||
304 | |||
305 | /* called from fsnotify listeners, such as fanotify or dnotify */ | ||
306 | |||
307 | /* must call when a group changes its ->mask */ | ||
308 | extern void fsnotify_recalc_global_mask(void); | ||
309 | /* get a reference to an existing or create a new group */ | ||
310 | extern struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num, | ||
311 | __u32 mask, | ||
312 | const struct fsnotify_ops *ops); | ||
313 | /* run all marks associated with this group and update group->mask */ | ||
314 | extern void fsnotify_recalc_group_mask(struct fsnotify_group *group); | ||
315 | /* drop reference on a group from fsnotify_obtain_group */ | ||
316 | extern void fsnotify_put_group(struct fsnotify_group *group); | ||
317 | |||
318 | /* take a reference to an event */ | ||
319 | extern void fsnotify_get_event(struct fsnotify_event *event); | ||
320 | extern void fsnotify_put_event(struct fsnotify_event *event); | ||
321 | /* find private data previously attached to an event and unlink it */ | ||
322 | extern struct fsnotify_event_private_data *fsnotify_remove_priv_from_event(struct fsnotify_group *group, | ||
323 | struct fsnotify_event *event); | ||
324 | |||
325 | /* attach the event to the group notification queue */ | ||
326 | extern int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event, | ||
327 | struct fsnotify_event_private_data *priv); | ||
328 | /* true if the group notification queue is empty */ | ||
329 | extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group); | ||
330 | /* return, but do not dequeue the first event on the notification queue */ | ||
331 | extern struct fsnotify_event *fsnotify_peek_notify_event(struct fsnotify_group *group); | ||
332 | /* return AND dequeue the first event on the notification queue */ | ||
333 | extern struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group); | ||
334 | |||
335 | /* functions used to manipulate the marks attached to inodes */ | ||
336 | |||
337 | /* run all marks associated with an inode and update inode->i_fsnotify_mask */ | ||
338 | extern void fsnotify_recalc_inode_mask(struct inode *inode); | ||
339 | extern void fsnotify_init_mark(struct fsnotify_mark_entry *entry, void (*free_mark)(struct fsnotify_mark_entry *entry)); | ||
340 | /* find (and take a reference) to a mark associated with group and inode */ | ||
341 | extern struct fsnotify_mark_entry *fsnotify_find_mark_entry(struct fsnotify_group *group, struct inode *inode); | ||
342 | /* attach the mark to both the group and the inode */ | ||
343 | extern int fsnotify_add_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group, struct inode *inode); | ||
344 | /* given a mark, flag it to be freed when all references are dropped */ | ||
345 | extern void fsnotify_destroy_mark_by_entry(struct fsnotify_mark_entry *entry); | ||
346 | /* run all the marks in a group, and flag them to be freed */ | ||
347 | extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group); | ||
348 | extern void fsnotify_get_mark(struct fsnotify_mark_entry *entry); | ||
349 | extern void fsnotify_put_mark(struct fsnotify_mark_entry *entry); | ||
350 | extern void fsnotify_unmount_inodes(struct list_head *list); | ||
351 | |||
352 | /* put here because inotify does some weird stuff when destroying watches */ | ||
353 | extern struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, | ||
354 | void *data, int data_is, const char *name, | ||
355 | u32 cookie); | ||
356 | |||
357 | #else | ||
358 | |||
359 | static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, | ||
360 | const char *name, u32 cookie) | ||
361 | {} | ||
362 | |||
363 | static inline void __fsnotify_parent(struct dentry *dentry, __u32 mask) | ||
364 | {} | ||
365 | |||
366 | static inline void __fsnotify_inode_delete(struct inode *inode) | ||
367 | {} | ||
368 | |||
369 | static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) | ||
370 | {} | ||
371 | |||
372 | static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) | ||
373 | {} | ||
374 | |||
375 | static inline u32 fsnotify_get_cookie(void) | ||
376 | { | ||
377 | return 0; | ||
378 | } | ||
379 | |||
380 | static inline void fsnotify_unmount_inodes(struct list_head *list) | ||
381 | {} | ||
382 | |||
383 | #endif /* CONFIG_FSNOTIFY */ | ||
384 | |||
385 | #endif /* __KERNEL __ */ | ||
386 | |||
387 | #endif /* __LINUX_FSNOTIFY_BACKEND_H */ | ||
diff --git a/init/Kconfig b/init/Kconfig index 9b68fee8d79e..c649657e2259 100644 --- a/init/Kconfig +++ b/init/Kconfig | |||
@@ -302,7 +302,8 @@ config AUDITSYSCALL | |||
302 | 302 | ||
303 | config AUDIT_TREE | 303 | config AUDIT_TREE |
304 | def_bool y | 304 | def_bool y |
305 | depends on AUDITSYSCALL && INOTIFY | 305 | depends on AUDITSYSCALL |
306 | select INOTIFY | ||
306 | 307 | ||
307 | menu "RCU Subsystem" | 308 | menu "RCU Subsystem" |
308 | 309 | ||