fsnotify: store struct file not struct path

Al explains that calling dentry_open() with a mnt/dentry pair is only
garunteed to be safe if they are already used in an open struct file.  To
make sure this is the case don't store and use a struct path in fsnotify,
always use a struct file.

Signed-off-by: Eric Paris <eparis@redhat.com>

1 files changed, 9 insertions, 11 deletions

diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index f39260f8f865..c106cdd7ff5e 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -31,6 +31,7 @@
  * allocated and used.
  */
 
+#include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
@@ -89,8 +90,8 @@ void fsnotify_put_event(struct fsnotify_event *event)
 	if (atomic_dec_and_test(&event->refcnt)) {
 		pr_debug("%s: event=%p\n", __func__, event);
 
-		if (event->data_type == FSNOTIFY_EVENT_PATH)
-			path_put(&event->path);
+		if (event->data_type == FSNOTIFY_EVENT_FILE)
+			fput(event->file);
 
 		BUG_ON(!list_empty(&event->private_data_list));
 
@@ -375,8 +376,8 @@ struct fsnotify_event *fsnotify_clone_event(struct fsnotify_event *old_event)
 		}
 	}
 	event->tgid = get_pid(old_event->tgid);
-	if (event->data_type == FSNOTIFY_EVENT_PATH)
-		path_get(&event->path);
+	if (event->data_type == FSNOTIFY_EVENT_FILE)
+		get_file(event->file);
 
 	return event;
 }
@@ -423,11 +424,9 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
 	event->data_type = data_type;
 
 	switch (data_type) {
-	case FSNOTIFY_EVENT_PATH: {
-		struct path *path = data;
-		event->path.dentry = path->dentry;
-		event->path.mnt = path->mnt;
-		path_get(&event->path);
+	case FSNOTIFY_EVENT_FILE: {
+		event->file = data;
+		get_file(event->file);
 		break;
 	}
 	case FSNOTIFY_EVENT_INODE:
@@ -435,8 +434,7 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
 		break;
 	case FSNOTIFY_EVENT_NONE:
 		event->inode = NULL;
-		event->path.dentry = NULL;
-		event->path.mnt = NULL;
+		event->file = NULL;
 		break;
 	default:
 		BUG();