42 	struct audit_chunk *chunk;  member
50  * One struct chunk is attached to each inode of interest through
51  * audit_tree_mark (fsnotify mark). We replace struct chunk on tagging /
52  * untagging, the mark is stable as long as there is chunk attached. The
53  * association between mark and chunk is protected by hash_lock and
57  * the current chunk.
62  * References to struct chunk are collected at audit_inode{,_child}()
68  * tree.chunks anchors chunk.owners[].list			hash_lock
70  * chunk.trees anchors tree.same_root				hash_lock
71  * chunk.hash is a hash with middle bits of watch.inode as
75  * it", one for each chunk with pointer to it.
77  * chunk is refcounted by embedded .refs. Mark associated with the chunk holds
78  * one chunk reference. This reference is dropped either when a mark is going
79  * to be freed (corresponding inode goes away) or when chunk attached to the
84  * node.index allows to get from node.list to containing chunk.
130 static void free_chunk(struct audit_chunk *chunk)  in free_chunk()  argument
134 	for (i = 0; i < chunk->count; i++) {  in free_chunk()
135 		if (chunk->owners[i].owner)  in free_chunk()
136 			put_tree(chunk->owners[i].owner);  in free_chunk()
138 	kfree(chunk);  in free_chunk()
141 void audit_put_chunk(struct audit_chunk *chunk)  in audit_put_chunk()  argument
143 	if (atomic_long_dec_and_test(&chunk->refs))  in audit_put_chunk()
144 		free_chunk(chunk);  in audit_put_chunk()
149 	struct audit_chunk *chunk = container_of(rcu, struct audit_chunk, head);  in __put_chunk()  local
150 	audit_put_chunk(chunk);  in __put_chunk()
154  * Drop reference to the chunk that was held by the mark. This is the reference
155  * that gets dropped after we've removed the chunk from the hash table and we
156  * use it to make sure chunk cannot be freed before RCU grace period expires.
158 static void audit_mark_put_chunk(struct audit_chunk *chunk)  in audit_mark_put_chunk()  argument
160 	call_rcu(&chunk->head, __put_chunk);  in audit_mark_put_chunk()
170 	return audit_mark(mark)->chunk;  in mark_chunk()
192 	struct audit_chunk *chunk;  in alloc_chunk()  local
195 	chunk = kzalloc(struct_size(chunk, owners, count), GFP_KERNEL);  in alloc_chunk()
196 	if (!chunk)  in alloc_chunk()
199 	INIT_LIST_HEAD(&chunk->hash);  in alloc_chunk()
200 	INIT_LIST_HEAD(&chunk->trees);  in alloc_chunk()
201 	chunk->count = count;  in alloc_chunk()
202 	atomic_long_set(&chunk->refs, 1);  in alloc_chunk()
204 		INIT_LIST_HEAD(&chunk->owners[i].list);  in alloc_chunk()
205 		chunk->owners[i].index = i;  in alloc_chunk()
207 	return chunk;  in alloc_chunk()
228 static void insert_hash(struct audit_chunk *chunk)  in insert_hash()  argument
233 	 * Make sure chunk is fully initialized before making it visible in the  in insert_hash()
238 	WARN_ON_ONCE(!chunk->key);  in insert_hash()
239 	list = chunk_hash(chunk->key);  in insert_hash()
240 	list_add_rcu(&chunk->hash, list);  in insert_hash()
253 		 * the chunk we see is fully initialized.  in audit_tree_lookup()
263 bool audit_tree_match(struct audit_chunk *chunk, struct audit_tree *tree)  in audit_tree_match()  argument
266 	for (n = 0; n < chunk->count; n++)  in audit_tree_match()
267 		if (chunk->owners[n].owner == tree)  in audit_tree_match()
282 			       struct audit_chunk *chunk)  in replace_mark_chunk()  argument
288 	audit_mark(mark)->chunk = chunk;  in replace_mark_chunk()
289 	if (chunk)  in replace_mark_chunk()
290 		chunk->mark = mark;  in replace_mark_chunk()
319 	 * Make sure chunk is fully initialized before making it visible in the  in replace_chunk()
327 static void remove_chunk_node(struct audit_chunk *chunk, struct audit_node *p)  in remove_chunk_node()  argument
331 	if (owner->root == chunk) {  in remove_chunk_node()
340 static int chunk_count_trees(struct audit_chunk *chunk)  in chunk_count_trees()  argument
345 	for (i = 0; i < chunk->count; i++)  in chunk_count_trees()
346 		if (chunk->owners[i].owner)  in chunk_count_trees()
351 static void untag_chunk(struct audit_chunk *chunk, struct fsnotify_mark *mark)  in untag_chunk()  argument
358 	 * mark_mutex stabilizes chunk attached to the mark so we can check  in untag_chunk()
362 	    mark_chunk(mark) != chunk)  in untag_chunk()
365 	size = chunk_count_trees(chunk);  in untag_chunk()
368 		list_del_init(&chunk->trees);  in untag_chunk()
369 		list_del_rcu(&chunk->hash);  in untag_chunk()
374 		audit_mark_put_chunk(chunk);  in untag_chunk()
385 	 * This has to go last when updating chunk as once replace_chunk() is  in untag_chunk()
386 	 * called, new RCU readers can see the new chunk.  in untag_chunk()
388 	replace_chunk(new, chunk);  in untag_chunk()
391 	audit_mark_put_chunk(chunk);  in untag_chunk()
402 	struct audit_chunk *chunk = alloc_chunk(1);  in create_chunk()  local
404 	if (!chunk) {  in create_chunk()
412 		kfree(chunk);  in create_chunk()
419 		kfree(chunk);  in create_chunk()
430 		kfree(chunk);  in create_chunk()
433 	replace_mark_chunk(mark, chunk);  in create_chunk()
434 	chunk->owners[0].index = (1U << 31);  in create_chunk()
435 	chunk->owners[0].owner = tree;  in create_chunk()
437 	list_add(&chunk->owners[0].list, &tree->chunks);  in create_chunk()
439 		tree->root = chunk;  in create_chunk()
440 		list_add(&tree->same_root, &chunk->trees);  in create_chunk()
442 	chunk->key = inode_to_key(inode);  in create_chunk()
445 	 * readers can see the chunk.  in create_chunk()
447 	insert_hash(chunk);  in create_chunk()
453 	 * chunk pointing to this mark.  in create_chunk()
463 	struct audit_chunk *chunk, *old;  in tag_chunk()  local
474 	 * from getting detached and thus it makes sure there is chunk attached  in tag_chunk()
490 	chunk = alloc_chunk(old->count + 1);  in tag_chunk()
491 	if (!chunk) {  in tag_chunk()
502 		kfree(chunk);  in tag_chunk()
505 	p = &chunk->owners[chunk->count - 1];  in tag_chunk()
506 	p->index = (chunk->count - 1) | (1U<<31);  in tag_chunk()
511 		tree->root = chunk;  in tag_chunk()
512 		list_add(&tree->same_root, &chunk->trees);  in tag_chunk()
515 	 * This has to go last when updating chunk as once replace_chunk() is  in tag_chunk()
516 	 * called, new RCU readers can see the new chunk.  in tag_chunk()
518 	replace_chunk(chunk, old);  in tag_chunk()
576 		struct audit_chunk *chunk;  in prune_tree_chunks()  local
583 		chunk = find_chunk(p);  in prune_tree_chunks()
584 		mark = chunk->mark;  in prune_tree_chunks()
585 		remove_chunk_node(chunk, p);  in prune_tree_chunks()
592 		untag_chunk(chunk, mark);  in prune_tree_chunks()
703 			struct audit_chunk *chunk = find_chunk(node);  in audit_trim_trees()  local
708 				if (inode_to_key(inode) == chunk->key) {  in audit_trim_trees()
1008 static void evict_chunk(struct audit_chunk *chunk)  in evict_chunk()  argument
1017 	while (!list_empty(&chunk->trees)) {  in evict_chunk()
1018 		owner = list_entry(chunk->trees.next,  in evict_chunk()
1033 	list_del_rcu(&chunk->hash);  in evict_chunk()
1034 	for (n = 0; n < chunk->count; n++)  in evict_chunk()
1035 		list_del_init(&chunk->owners[n].list);  in evict_chunk()
1052 	struct audit_chunk *chunk;  in audit_tree_freeing_mark()  local
1056 	chunk = mark_chunk(mark);  in audit_tree_freeing_mark()
1060 	if (chunk) {  in audit_tree_freeing_mark()
1061 		evict_chunk(chunk);  in audit_tree_freeing_mark()
1062 		audit_mark_put_chunk(chunk);  in audit_tree_freeing_mark()