[PATCH] inotify (3/5): add interfaces to kernel API
Add inotify_init_watch() so caller can use inotify_watch refcounts
before calling inotify_add_watch().
Add inotify_find_watch() to find an existing watch for an (ih,inode)
pair. This is similar to inotify_find_update_watch(), but does not
update the watch's mask if one is found.
Add inotify_rm_watch() to remove a watch via the watch pointer instead
of the watch descriptor.
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Acked-by: Robert Love <rml@novell.com>
Acked-by: John McCutchan <john@johnmccutchan.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/inotify.c b/fs/inotify.c
index f25c218..8477c4f 100644
--- a/fs/inotify.c
+++ b/fs/inotify.c
@@ -468,6 +468,19 @@
EXPORT_SYMBOL_GPL(inotify_init);
/**
+ * inotify_init_watch - initialize an inotify watch
+ * @watch: watch to initialize
+ */
+void inotify_init_watch(struct inotify_watch *watch)
+{
+ INIT_LIST_HEAD(&watch->h_list);
+ INIT_LIST_HEAD(&watch->i_list);
+ atomic_set(&watch->count, 0);
+ get_inotify_watch(watch); /* initial get */
+}
+EXPORT_SYMBOL_GPL(inotify_init_watch);
+
+/**
* inotify_destroy - clean up and destroy an inotify instance
* @ih: inotify handle
*/
@@ -515,6 +528,37 @@
EXPORT_SYMBOL_GPL(inotify_destroy);
/**
+ * inotify_find_watch - find an existing watch for an (ih,inode) pair
+ * @ih: inotify handle
+ * @inode: inode to watch
+ * @watchp: pointer to existing inotify_watch
+ *
+ * Caller must pin given inode (via nameidata).
+ */
+s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,
+ struct inotify_watch **watchp)
+{
+ struct inotify_watch *old;
+ int ret = -ENOENT;
+
+ mutex_lock(&inode->inotify_mutex);
+ mutex_lock(&ih->mutex);
+
+ old = inode_find_handle(inode, ih);
+ if (unlikely(old)) {
+ get_inotify_watch(old); /* caller must put watch */
+ *watchp = old;
+ ret = old->wd;
+ }
+
+ mutex_unlock(&ih->mutex);
+ mutex_unlock(&inode->inotify_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(inotify_find_watch);
+
+/**
* inotify_find_update_watch - find and update the mask of an existing watch
* @ih: inotify handle
* @inode: inode's watch to update
@@ -593,10 +637,6 @@
goto out;
ret = watch->wd;
- atomic_set(&watch->count, 0);
- INIT_LIST_HEAD(&watch->h_list);
- INIT_LIST_HEAD(&watch->i_list);
-
/* save a reference to handle and bump the count to make it official */
get_inotify_handle(ih);
watch->ih = ih;
@@ -607,8 +647,6 @@
*/
watch->inode = igrab(inode);
- get_inotify_watch(watch); /* initial get */
-
if (!inotify_inode_watched(inode))
set_dentry_child_flags(inode, 1);
@@ -659,6 +697,20 @@
}
EXPORT_SYMBOL_GPL(inotify_rm_wd);
+/**
+ * inotify_rm_watch - remove a watch from an inotify instance
+ * @ih: inotify handle
+ * @watch: watch to remove
+ *
+ * Can sleep.
+ */
+int inotify_rm_watch(struct inotify_handle *ih,
+ struct inotify_watch *watch)
+{
+ return inotify_rm_wd(ih, watch->wd);
+}
+EXPORT_SYMBOL_GPL(inotify_rm_watch);
+
/*
* inotify_setup - core initialization function
*/