+config FSNOTIFY
+ bool "Filesystem notification backend"
+ default y
+ ---help---
+ fsnotify is a backend for filesystem notification. fsnotify does
+ not provide any userspace interface but does provide the basis
+ needed for other notification schemes such as dnotify, inotify,
+ and fanotify.
+
+ Say Y here to enable fsnotify suport.
+
+ If unsure, say Y.
+
source "fs/notify/dnotify/Kconfig"
source "fs/notify/inotify/Kconfig"
+obj-$(CONFIG_FSNOTIFY) += fsnotify.o notification.o group.o
+
obj-y += dnotify/
obj-y += inotify/
--- /dev/null
+/*
+ * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/dcache.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/srcu.h>
+
+#include <linux/fsnotify_backend.h>
+#include "fsnotify.h"
+
+/*
+ * This is the main call to fsnotify. The VFS calls into hook specific functions
+ * in linux/fsnotify.h. Those functions then in turn call here. Here will call
+ * out to all of the registered fsnotify_group. Those groups can then use the
+ * notification event in whatever means they feel necessary.
+ */
+void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is)
+{
+ struct fsnotify_group *group;
+ struct fsnotify_event *event = NULL;
+ int idx;
+
+ if (list_empty(&fsnotify_groups))
+ return;
+
+ if (!(mask & fsnotify_mask))
+ return;
+
+ /*
+ * SRCU!! the groups list is very very much read only and the path is
+ * very hot. The VAST majority of events are not going to need to do
+ * anything other than walk the list so it's crazy to pre-allocate.
+ */
+ idx = srcu_read_lock(&fsnotify_grp_srcu);
+ list_for_each_entry_rcu(group, &fsnotify_groups, group_list) {
+ if (mask & group->mask) {
+ if (!event) {
+ event = fsnotify_create_event(to_tell, mask, data, data_is);
+ /* shit, we OOM'd and now we can't tell, maybe
+ * someday someone else will want to do something
+ * here */
+ if (!event)
+ break;
+ }
+ group->ops->handle_event(group, event);
+ }
+ }
+ srcu_read_unlock(&fsnotify_grp_srcu, idx);
+ /*
+ * fsnotify_create_event() took a reference so the event can't be cleaned
+ * up while we are still trying to add it to lists, drop that one.
+ */
+ if (event)
+ fsnotify_put_event(event);
+}
+EXPORT_SYMBOL_GPL(fsnotify);
+
+static __init int fsnotify_init(void)
+{
+ return init_srcu_struct(&fsnotify_grp_srcu);
+}
+subsys_initcall(fsnotify_init);
--- /dev/null
+#ifndef __FS_NOTIFY_FSNOTIFY_H_
+#define __FS_NOTIFY_FSNOTIFY_H_
+
+#include <linux/list.h>
+#include <linux/fsnotify.h>
+#include <linux/srcu.h>
+#include <linux/types.h>
+
+/* protects reads of fsnotify_groups */
+extern struct srcu_struct fsnotify_grp_srcu;
+/* all groups which receive fsnotify events */
+extern struct list_head fsnotify_groups;
+/* all bitwise OR of all event types (FS_*) for all fsnotify_groups */
+extern __u32 fsnotify_mask;
+#endif /* __FS_NOTIFY_FSNOTIFY_H_ */
--- /dev/null
+/*
+ * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/srcu.h>
+#include <linux/rculist.h>
+#include <linux/wait.h>
+
+#include <linux/fsnotify_backend.h>
+#include "fsnotify.h"
+
+#include <asm/atomic.h>
+
+/* protects writes to fsnotify_groups and fsnotify_mask */
+static DEFINE_MUTEX(fsnotify_grp_mutex);
+/* protects reads while running the fsnotify_groups list */
+struct srcu_struct fsnotify_grp_srcu;
+/* all groups registered to receive filesystem notifications */
+LIST_HEAD(fsnotify_groups);
+/* bitwise OR of all events (FS_*) interesting to some group on this system */
+__u32 fsnotify_mask;
+
+/*
+ * When a new group registers or changes it's set of interesting events
+ * this function updates the fsnotify_mask to contain all interesting events
+ */
+void fsnotify_recalc_global_mask(void)
+{
+ struct fsnotify_group *group;
+ __u32 mask = 0;
+ int idx;
+
+ idx = srcu_read_lock(&fsnotify_grp_srcu);
+ list_for_each_entry_rcu(group, &fsnotify_groups, group_list)
+ mask |= group->mask;
+ srcu_read_unlock(&fsnotify_grp_srcu, idx);
+ fsnotify_mask = mask;
+}
+
+/*
+ * Take a reference to a group so things found under the fsnotify_grp_mutex
+ * can't get freed under us
+ */
+static void fsnotify_get_group(struct fsnotify_group *group)
+{
+ atomic_inc(&group->refcnt);
+}
+
+/*
+ * Final freeing of a group
+ */
+static void fsnotify_destroy_group(struct fsnotify_group *group)
+{
+ if (group->ops->free_group_priv)
+ group->ops->free_group_priv(group);
+
+ kfree(group);
+}
+
+/*
+ * Remove this group from the global list of groups that will get events
+ * this can be done even if there are still references and things still using
+ * this group. This just stops the group from getting new events.
+ */
+static void __fsnotify_evict_group(struct fsnotify_group *group)
+{
+ BUG_ON(!mutex_is_locked(&fsnotify_grp_mutex));
+
+ if (group->on_group_list)
+ list_del_rcu(&group->group_list);
+ group->on_group_list = 0;
+}
+
+/*
+ * Called when a group is no longer interested in getting events. This can be
+ * used if a group is misbehaving or if for some reason a group should no longer
+ * get any filesystem events.
+ */
+void fsnotify_evict_group(struct fsnotify_group *group)
+{
+ mutex_lock(&fsnotify_grp_mutex);
+ __fsnotify_evict_group(group);
+ mutex_unlock(&fsnotify_grp_mutex);
+}
+
+/*
+ * Drop a reference to a group. Free it if it's through.
+ */
+void fsnotify_put_group(struct fsnotify_group *group)
+{
+ if (!atomic_dec_and_mutex_lock(&group->refcnt, &fsnotify_grp_mutex))
+ return;
+
+ /*
+ * OK, now we know that there's no other users *and* we hold mutex,
+ * so no new references will appear
+ */
+ __fsnotify_evict_group(group);
+
+ /*
+ * now it's off the list, so the only thing we might care about is
+ * srcu access....
+ */
+ mutex_unlock(&fsnotify_grp_mutex);
+ synchronize_srcu(&fsnotify_grp_srcu);
+
+ /* and now it is really dead. _Nothing_ could be seeing it */
+ fsnotify_recalc_global_mask();
+ fsnotify_destroy_group(group);
+}
+
+/*
+ * Simply run the fsnotify_groups list and find a group which matches
+ * the given parameters. If a group is found we take a reference to that
+ * group.
+ */
+static struct fsnotify_group *fsnotify_find_group(unsigned int group_num, __u32 mask,
+ const struct fsnotify_ops *ops)
+{
+ struct fsnotify_group *group_iter;
+ struct fsnotify_group *group = NULL;
+
+ BUG_ON(!mutex_is_locked(&fsnotify_grp_mutex));
+
+ list_for_each_entry_rcu(group_iter, &fsnotify_groups, group_list) {
+ if (group_iter->group_num == group_num) {
+ if ((group_iter->mask == mask) &&
+ (group_iter->ops == ops)) {
+ fsnotify_get_group(group_iter);
+ group = group_iter;
+ } else
+ group = ERR_PTR(-EEXIST);
+ }
+ }
+ return group;
+}
+
+/*
+ * Either finds an existing group which matches the group_num, mask, and ops or
+ * creates a new group and adds it to the global group list. In either case we
+ * take a reference for the group returned.
+ */
+struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num, __u32 mask,
+ const struct fsnotify_ops *ops)
+{
+ struct fsnotify_group *group, *tgroup;
+
+ /* very low use, simpler locking if we just always alloc */
+ group = kmalloc(sizeof(struct fsnotify_group), GFP_KERNEL);
+ if (!group)
+ return ERR_PTR(-ENOMEM);
+
+ atomic_set(&group->refcnt, 1);
+
+ group->on_group_list = 0;
+ group->group_num = group_num;
+ group->mask = mask;
+
+ group->ops = ops;
+
+ mutex_lock(&fsnotify_grp_mutex);
+ tgroup = fsnotify_find_group(group_num, mask, ops);
+ if (tgroup) {
+ /* group already exists */
+ mutex_unlock(&fsnotify_grp_mutex);
+ /* destroy the new one we made */
+ fsnotify_put_group(group);
+ return tgroup;
+ }
+
+ /* group not found, add a new one */
+ list_add_rcu(&group->group_list, &fsnotify_groups);
+ group->on_group_list = 1;
+
+ mutex_unlock(&fsnotify_grp_mutex);
+
+ if (mask)
+ fsnotify_recalc_global_mask();
+
+ return group;
+}
#include <linux/list.h>
#include <linux/writeback.h>
#include <linux/inotify.h>
+#include <linux/fsnotify_backend.h>
static atomic_t inotify_cookie;
*/
static int __init inotify_setup(void)
{
+ BUILD_BUG_ON(IN_ACCESS != FS_ACCESS);
+ BUILD_BUG_ON(IN_MODIFY != FS_MODIFY);
+ BUILD_BUG_ON(IN_ATTRIB != FS_ATTRIB);
+ BUILD_BUG_ON(IN_CLOSE_WRITE != FS_CLOSE_WRITE);
+ BUILD_BUG_ON(IN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
+ BUILD_BUG_ON(IN_OPEN != FS_OPEN);
+ BUILD_BUG_ON(IN_MOVED_FROM != FS_MOVED_FROM);
+ BUILD_BUG_ON(IN_MOVED_TO != FS_MOVED_TO);
+ BUILD_BUG_ON(IN_CREATE != FS_CREATE);
+ BUILD_BUG_ON(IN_DELETE != FS_DELETE);
+ BUILD_BUG_ON(IN_DELETE_SELF != FS_DELETE_SELF);
+ BUILD_BUG_ON(IN_MOVE_SELF != FS_MOVE_SELF);
+ BUILD_BUG_ON(IN_Q_OVERFLOW != FS_Q_OVERFLOW);
+
+ BUILD_BUG_ON(IN_UNMOUNT != FS_UNMOUNT);
+ BUILD_BUG_ON(IN_ISDIR != FS_IN_ISDIR);
+ BUILD_BUG_ON(IN_IGNORED != FS_IN_IGNORED);
+ BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT);
+
atomic_set(&inotify_cookie, 0);
return 0;
--- /dev/null
+/*
+ * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/mount.h>
+#include <linux/mutex.h>
+#include <linux/namei.h>
+#include <linux/path.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <asm/atomic.h>
+
+#include <linux/fsnotify_backend.h>
+#include "fsnotify.h"
+
+static struct kmem_cache *fsnotify_event_cachep;
+
+void fsnotify_get_event(struct fsnotify_event *event)
+{
+ atomic_inc(&event->refcnt);
+}
+
+void fsnotify_put_event(struct fsnotify_event *event)
+{
+ if (!event)
+ return;
+
+ if (atomic_dec_and_test(&event->refcnt)) {
+ if (event->data_type == FSNOTIFY_EVENT_PATH)
+ path_put(&event->path);
+
+ kmem_cache_free(fsnotify_event_cachep, event);
+ }
+}
+
+/*
+ * Allocate a new event which will be sent to each group's handle_event function
+ * if the group was interested in this particular event.
+ */
+struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
+ void *data, int data_type)
+{
+ struct fsnotify_event *event;
+
+ event = kmem_cache_alloc(fsnotify_event_cachep, GFP_KERNEL);
+ if (!event)
+ return NULL;
+
+ atomic_set(&event->refcnt, 1);
+
+ spin_lock_init(&event->lock);
+
+ event->path.dentry = NULL;
+ event->path.mnt = NULL;
+ event->inode = NULL;
+
+ event->to_tell = to_tell;
+
+ switch (data_type) {
+ case FSNOTIFY_EVENT_FILE: {
+ struct file *file = data;
+ struct path *path = &file->f_path;
+ event->path.dentry = path->dentry;
+ event->path.mnt = path->mnt;
+ path_get(&event->path);
+ event->data_type = FSNOTIFY_EVENT_PATH;
+ break;
+ }
+ case FSNOTIFY_EVENT_PATH: {
+ struct path *path = data;
+ event->path.dentry = path->dentry;
+ event->path.mnt = path->mnt;
+ path_get(&event->path);
+ event->data_type = FSNOTIFY_EVENT_PATH;
+ break;
+ }
+ case FSNOTIFY_EVENT_INODE:
+ event->inode = data;
+ event->data_type = FSNOTIFY_EVENT_INODE;
+ break;
+ case FSNOTIFY_EVENT_NONE:
+ event->inode = NULL;
+ event->path.dentry = NULL;
+ event->path.mnt = NULL;
+ break;
+ default:
+ BUG();
+ }
+
+ event->mask = mask;
+
+ return event;
+}
+
+__init int fsnotify_notification_init(void)
+{
+ fsnotify_event_cachep = KMEM_CACHE(fsnotify_event, SLAB_PANIC);
+
+ return 0;
+}
+subsys_initcall(fsnotify_notification_init);
+
#include <linux/dnotify.h>
#include <linux/inotify.h>
+#include <linux/fsnotify_backend.h>
#include <linux/audit.h>
/*
inotify_d_move(entry);
}
+/*
+ * fsnotify_link_count - inode's link count changed
+ */
+static inline void fsnotify_link_count(struct inode *inode)
+{
+ inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL);
+
+ fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE);
+}
+
/*
* fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
*/
{
struct inode *source = moved->d_inode;
u32 cookie = inotify_get_cookie();
+ __u32 old_dir_mask = 0;
+ __u32 new_dir_mask = 0;
- if (old_dir == new_dir)
+ if (old_dir == new_dir) {
inode_dir_notify(old_dir, DN_RENAME);
- else {
+ old_dir_mask = FS_DN_RENAME;
+ } else {
inode_dir_notify(old_dir, DN_DELETE);
+ old_dir_mask = FS_DELETE;
inode_dir_notify(new_dir, DN_CREATE);
+ new_dir_mask = FS_CREATE;
}
- if (isdir)
+ if (isdir) {
isdir = IN_ISDIR;
+ old_dir_mask |= FS_IN_ISDIR;
+ new_dir_mask |= FS_IN_ISDIR;
+ }
+
+ old_dir_mask |= FS_MOVED_FROM;
+ new_dir_mask |= FS_MOVED_TO;
+
inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir,cookie,old_name,
source);
inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name,
source);
+ fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE);
+ fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE);
+
if (target) {
inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL, NULL);
inotify_inode_is_dead(target);
+
+ /* this is really a link_count change not a removal */
+ fsnotify_link_count(target);
}
if (source) {
inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL);
+ fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE);
}
audit_inode_child(new_name, moved, new_dir);
}
*/
static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
{
+ __u32 mask = FS_DELETE;
+
if (isdir)
- isdir = IN_ISDIR;
+ mask |= FS_IN_ISDIR;
dnotify_parent(dentry, DN_DELETE);
- inotify_dentry_parent_queue_event(dentry, IN_DELETE|isdir, 0, dentry->d_name.name);
+ inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
}
/*
{
inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL, NULL);
inotify_inode_is_dead(inode);
-}
-/*
- * fsnotify_link_count - inode's link count changed
- */
-static inline void fsnotify_link_count(struct inode *inode)
-{
- inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL);
+ fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE);
}
/*
inotify_inode_queue_event(inode, IN_CREATE, 0, dentry->d_name.name,
dentry->d_inode);
audit_inode_child(dentry->d_name.name, dentry, inode);
+
+ fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE);
}
/*
inode);
fsnotify_link_count(inode);
audit_inode_child(new_dentry->d_name.name, new_dentry, dir);
+
+ fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE);
}
/*
*/
static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
{
+ __u32 mask = (FS_CREATE | FS_IN_ISDIR);
+ struct inode *d_inode = dentry->d_inode;
+
inode_dir_notify(inode, DN_CREATE);
- inotify_inode_queue_event(inode, IN_CREATE | IN_ISDIR, 0,
- dentry->d_name.name, dentry->d_inode);
+ inotify_inode_queue_event(inode, mask, 0, dentry->d_name.name, d_inode);
audit_inode_child(dentry->d_name.name, dentry, inode);
+
+ fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE);
}
/*
static inline void fsnotify_access(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
- u32 mask = IN_ACCESS;
+ __u32 mask = FS_ACCESS;
if (S_ISDIR(inode->i_mode))
- mask |= IN_ISDIR;
+ mask |= FS_IN_ISDIR;
dnotify_parent(dentry, DN_ACCESS);
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
+
+ fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
}
/*
static inline void fsnotify_modify(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
- u32 mask = IN_MODIFY;
+ __u32 mask = FS_MODIFY;
if (S_ISDIR(inode->i_mode))
- mask |= IN_ISDIR;
+ mask |= FS_IN_ISDIR;
dnotify_parent(dentry, DN_MODIFY);
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
+
+ fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
}
/*
static inline void fsnotify_open(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
- u32 mask = IN_OPEN;
+ __u32 mask = FS_OPEN;
if (S_ISDIR(inode->i_mode))
- mask |= IN_ISDIR;
+ mask |= FS_IN_ISDIR;
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
+
+ fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
}
/*
struct inode *inode = dentry->d_inode;
const char *name = dentry->d_name.name;
fmode_t mode = file->f_mode;
- u32 mask = (mode & FMODE_WRITE) ? IN_CLOSE_WRITE : IN_CLOSE_NOWRITE;
+ __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
if (S_ISDIR(inode->i_mode))
- mask |= IN_ISDIR;
+ mask |= FS_IN_ISDIR;
inotify_dentry_parent_queue_event(dentry, mask, 0, name);
inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
+
+ fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE);
}
/*
static inline void fsnotify_xattr(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
- u32 mask = IN_ATTRIB;
+ __u32 mask = FS_ATTRIB;
if (S_ISDIR(inode->i_mode))
- mask |= IN_ISDIR;
+ mask |= FS_IN_ISDIR;
inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
+
+ fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE);
}
/*
{
struct inode *inode = dentry->d_inode;
int dn_mask = 0;
- u32 in_mask = 0;
+ __u32 in_mask = 0;
if (ia_valid & ATTR_UID) {
- in_mask |= IN_ATTRIB;
+ in_mask |= FS_ATTRIB;
dn_mask |= DN_ATTRIB;
}
if (ia_valid & ATTR_GID) {
- in_mask |= IN_ATTRIB;
+ in_mask |= FS_ATTRIB;
dn_mask |= DN_ATTRIB;
}
if (ia_valid & ATTR_SIZE) {
- in_mask |= IN_MODIFY;
+ in_mask |= FS_MODIFY;
dn_mask |= DN_MODIFY;
}
/* both times implies a utime(s) call */
if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
{
- in_mask |= IN_ATTRIB;
+ in_mask |= FS_ATTRIB;
dn_mask |= DN_ATTRIB;
} else if (ia_valid & ATTR_ATIME) {
- in_mask |= IN_ACCESS;
+ in_mask |= FS_ACCESS;
dn_mask |= DN_ACCESS;
} else if (ia_valid & ATTR_MTIME) {
- in_mask |= IN_MODIFY;
+ in_mask |= FS_MODIFY;
dn_mask |= DN_MODIFY;
}
if (ia_valid & ATTR_MODE) {
- in_mask |= IN_ATTRIB;
+ in_mask |= FS_ATTRIB;
dn_mask |= DN_ATTRIB;
}
dnotify_parent(dentry, dn_mask);
if (in_mask) {
if (S_ISDIR(inode->i_mode))
- in_mask |= IN_ISDIR;
+ in_mask |= FS_IN_ISDIR;
inotify_inode_queue_event(inode, in_mask, 0, NULL, NULL);
inotify_dentry_parent_queue_event(dentry, in_mask, 0,
dentry->d_name.name);
+ fsnotify(inode, in_mask, inode, FSNOTIFY_EVENT_INODE);
}
}
-#ifdef CONFIG_INOTIFY /* inotify helpers */
+#if defined(CONFIG_INOTIFY) || defined(CONFIG_FSNOTIFY) /* notify helpers */
/*
* fsnotify_oldname_init - save off the old filename before we change it
kfree(old_name);
}
-#else /* CONFIG_INOTIFY */
+#else /* CONFIG_INOTIFY || CONFIG_FSNOTIFY */
static inline const char *fsnotify_oldname_init(const char *name)
{
--- /dev/null
+/*
+ * Filesystem access notification for Linux
+ *
+ * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
+ */
+
+#ifndef __LINUX_FSNOTIFY_BACKEND_H
+#define __LINUX_FSNOTIFY_BACKEND_H
+
+#ifdef __KERNEL__
+
+#include <linux/fs.h> /* struct inode */
+#include <linux/list.h>
+#include <linux/path.h> /* struct path */
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/atomic.h>
+
+/*
+ * IN_* from inotfy.h lines up EXACTLY with FS_*, this is so we can easily
+ * convert between them. dnotify only needs conversion at watch creation
+ * so no perf loss there. fanotify isn't defined yet, so it can use the
+ * wholes if it needs more events.
+ */
+#define FS_ACCESS 0x00000001 /* File was accessed */
+#define FS_MODIFY 0x00000002 /* File was modified */
+#define FS_ATTRIB 0x00000004 /* Metadata changed */
+#define FS_CLOSE_WRITE 0x00000008 /* Writtable file was closed */
+#define FS_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */
+#define FS_OPEN 0x00000020 /* File was opened */
+#define FS_MOVED_FROM 0x00000040 /* File was moved from X */
+#define FS_MOVED_TO 0x00000080 /* File was moved to Y */
+#define FS_CREATE 0x00000100 /* Subfile was created */
+#define FS_DELETE 0x00000200 /* Subfile was deleted */
+#define FS_DELETE_SELF 0x00000400 /* Self was deleted */
+#define FS_MOVE_SELF 0x00000800 /* Self was moved */
+
+#define FS_UNMOUNT 0x00002000 /* inode on umount fs */
+#define FS_Q_OVERFLOW 0x00004000 /* Event queued overflowed */
+#define FS_IN_IGNORED 0x00008000 /* last inotify event here */
+
+#define FS_IN_ISDIR 0x40000000 /* event occurred against dir */
+#define FS_IN_ONESHOT 0x80000000 /* only send event once */
+
+#define FS_DN_RENAME 0x10000000 /* file renamed */
+#define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */
+
+struct fsnotify_group;
+struct fsnotify_event;
+
+/*
+ * Each group much define these ops. The fsnotify infrastructure will call
+ * these operations for each relevant group.
+ *
+ * handle_event - main call for a group to handle an fs event
+ * free_group_priv - called when a group refcnt hits 0 to clean up the private union
+ */
+struct fsnotify_ops {
+ int (*handle_event)(struct fsnotify_group *group, struct fsnotify_event *event);
+ void (*free_group_priv)(struct fsnotify_group *group);
+};
+
+/*
+ * A group is a "thing" that wants to receive notification about filesystem
+ * events. The mask holds the subset of event types this group cares about.
+ * refcnt on a group is up to the implementor and at any moment if it goes 0
+ * everything will be cleaned up.
+ */
+struct fsnotify_group {
+ /*
+ * global list of all groups receiving events from fsnotify.
+ * anchored by fsnotify_groups and protected by either fsnotify_grp_mutex
+ * or fsnotify_grp_srcu depending on write vs read.
+ */
+ struct list_head group_list;
+
+ /*
+ * Defines all of the event types in which this group is interested.
+ * This mask is a bitwise OR of the FS_* events from above. Each time
+ * this mask changes for a group (if it changes) the correct functions
+ * must be called to update the global structures which indicate global
+ * interest in event types.
+ */
+ __u32 mask;
+
+ /*
+ * How the refcnt is used is up to each group. When the refcnt hits 0
+ * fsnotify will clean up all of the resources associated with this group.
+ * As an example, the dnotify group will always have a refcnt=1 and that
+ * will never change. Inotify, on the other hand, has a group per
+ * inotify_init() and the refcnt will hit 0 only when that fd has been
+ * closed.
+ */
+ atomic_t refcnt; /* things with interest in this group */
+ unsigned int group_num; /* simply prevents accidental group collision */
+
+ const struct fsnotify_ops *ops; /* how this group handles things */
+
+ /* prevents double list_del of group_list. protected by global fsnotify_gr_mutex */
+ bool on_group_list;
+
+ /* groups can define private fields here or use the void *private */
+ union {
+ void *private;
+ };
+};
+
+/*
+ * all of the information about the original object we want to now send to
+ * a group. If you want to carry more info from the accessing task to the
+ * listener this structure is where you need to be adding fields.
+ */
+struct fsnotify_event {
+ spinlock_t lock; /* protection for the associated event_holder and private_list */
+ /* to_tell may ONLY be dereferenced during handle_event(). */
+ struct inode *to_tell; /* either the inode the event happened to or its parent */
+ /*
+ * depending on the event type we should have either a path or inode
+ * We hold a reference on path, but NOT on inode. Since we have the ref on
+ * the path, it may be dereferenced at any point during this object's
+ * lifetime. That reference is dropped when this object's refcnt hits
+ * 0. If this event contains an inode instead of a path, the inode may
+ * ONLY be used during handle_event().
+ */
+ union {
+ struct path path;
+ struct inode *inode;
+ };
+/* when calling fsnotify tell it if the data is a path or inode */
+#define FSNOTIFY_EVENT_NONE 0
+#define FSNOTIFY_EVENT_PATH 1
+#define FSNOTIFY_EVENT_INODE 2
+#define FSNOTIFY_EVENT_FILE 3
+ int data_type; /* which of the above union we have */
+ atomic_t refcnt; /* how many groups still are using/need to send this event */
+ __u32 mask; /* the type of access, bitwise OR for FS_* event types */
+};
+
+#ifdef CONFIG_FSNOTIFY
+
+/* called from the vfs helpers */
+
+/* main fsnotify call to send events */
+extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is);
+
+
+/* called from fsnotify listeners, such as fanotify or dnotify */
+
+/* must call when a group changes its ->mask */
+extern void fsnotify_recalc_global_mask(void);
+/* get a reference to an existing or create a new group */
+extern struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num,
+ __u32 mask,
+ const struct fsnotify_ops *ops);
+/* drop reference on a group from fsnotify_obtain_group */
+extern void fsnotify_put_group(struct fsnotify_group *group);
+
+/* take a reference to an event */
+extern void fsnotify_get_event(struct fsnotify_event *event);
+extern void fsnotify_put_event(struct fsnotify_event *event);
+/* find private data previously attached to an event */
+extern struct fsnotify_event_private_data *fsnotify_get_priv_from_event(struct fsnotify_group *group,
+ struct fsnotify_event *event);
+
+/* put here because inotify does some weird stuff when destroying watches */
+extern struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
+ void *data, int data_is);
+#else
+
+static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is)
+{}
+#endif /* CONFIG_FSNOTIFY */
+
+#endif /* __KERNEL __ */
+
+#endif /* __LINUX_FSNOTIFY_BACKEND_H */
projects / linux-beck.git / commitdiff