audit: reimplement audit_trees using fsnotify rather than inotify

Simply switch audit_trees from using inotify to using fsnotify for it's
inode pinning and disappearing act information.
Signed-off-by: Eric Paris <eparis@redhat.com>

include/linux/fsnotify_backend.h

@@ -62,8 +62,9 @@
 
 /* listeners that hard code group numbers near the top */
 #define DNOTIFY_GROUP_NUM	UINT_MAX
-#define AUDIT_WATCH_GROUP_NUM  (DNOTIFY_GROUP_NUM-1)
-#define INOTIFY_GROUP_NUM      (AUDIT_WATCH_GROUP_NUM-1)
+#define AUDIT_WATCH_GROUP_NUM	(DNOTIFY_GROUP_NUM-1)
+#define AUDIT_TREE_GROUP_NUM	(AUDIT_WATCH_GROUP_NUM-1)
+#define INOTIFY_GROUP_NUM	(AUDIT_TREE_GROUP_NUM-1)
 
 struct fsnotify_group;
 struct fsnotify_event;

init/Kconfig

@@ -308,7 +308,7 @@ config AUDITSYSCALL
 config AUDIT_TREE
 	def_bool y
 	depends on AUDITSYSCALL
-	select INOTIFY
+	select FSNOTIFY
 
 menu "RCU Subsystem"
 

kernel/auditsc.c

@@ -1725,7 +1725,7 @@ static inline void handle_one(const struct inode *inode)
 	struct audit_tree_refs *p;
 	struct audit_chunk *chunk;
 	int count;
-	if (likely(list_empty(&inode->inotify_watches)))
+	if (likely(hlist_empty(&inode->i_fsnotify_mark_entries)))
 		return;
 	context = current->audit_context;
 	p = context->trees;
@@ -1768,7 +1768,7 @@ retry:
 	seq = read_seqbegin(&rename_lock);
 	for(;;) {
 		struct inode *inode = d->d_inode;
-		if (inode && unlikely(!list_empty(&inode->inotify_watches))) {
+		if (inode && unlikely(!hlist_empty(&inode->i_fsnotify_mark_entries))) {
 			struct audit_chunk *chunk;
 			chunk = audit_tree_lookup(inode);
 			if (chunk) {