from-4.9.18_inotify-IN_MASK_CREATE_to_4.9.0.diff

Index: fs/notify/inotify/inotify_user.c
===================================================================
--- fs.orig/notify/inotify/inotify_user.c
+++ fs/notify/inotify/inotify_user.c
@@ -522,6 +522,7 @@ static int inotify_update_existing_watch
 	__u32 old_mask, new_mask;
 	__u32 mask;
 	int add = (arg & IN_MASK_ADD);
+	int create = (arg & IN_MASK_CREATE);
 	int ret;

 	mask = inotify_arg_to_mask(arg);
@@ -529,6 +530,8 @@ static int inotify_update_existing_watch
 	fsn_mark = fsnotify_find_inode_mark(group, inode);
 	if (!fsn_mark)
 		return -ENOENT;
+	else if (create)
+		return -EEXIST;

 	i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);

@@ -726,6 +729,10 @@ SYSCALL_DEFINE3(inotify_add_watch, int,
 	if (unlikely(!f.file))
 		return -EBADF;

+	/* IN_MASK_ADD and IN_MASK_CREATE don't make sense together */
+	if (unlikely((mask & IN_MASK_ADD) && (mask & IN_MASK_CREATE)))
+		return -EINVAL;
+
 	/* verify that this is indeed an inotify instance */
 	if (unlikely(f.file->f_op != &inotify_fops)) {
 		ret = -EINVAL;
@@ -814,7 +821,7 @@ static int __init inotify_user_setup(voi
 	BUILD_BUG_ON(IN_ISDIR != FS_ISDIR);
 	BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT);

-	BUG_ON(hweight32(ALL_INOTIFY_BITS) != 21);
+	BUG_ON(hweight32(ALL_INOTIFY_BITS) != 22);

 	inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark, SLAB_PANIC);

Index: include/linux/inotify.h
===================================================================
--- include.orig/linux/inotify.h
+++ include/linux/inotify.h
@@ -17,6 +17,6 @@ extern struct ctl_table inotify_table[];
 			  IN_DELETE_SELF | IN_MOVE_SELF | IN_UNMOUNT | \
 			  IN_Q_OVERFLOW | IN_IGNORED | IN_ONLYDIR | \
 			  IN_DONT_FOLLOW | IN_EXCL_UNLINK | IN_MASK_ADD | \
-			  IN_ISDIR | IN_ONESHOT)
+			  IN_MASK_CREATE | IN_ISDIR | IN_ONESHOT)

 #endif	/* _LINUX_INOTIFY_H */
Index: include/uapi/linux/inotify.h
===================================================================
--- include.orig/uapi/linux/inotify.h
+++ include/uapi/linux/inotify.h
@@ -52,6 +52,7 @@ struct inotify_event {
 #define IN_ONLYDIR		0x01000000	/* only watch the path if it is a directory */
 #define IN_DONT_FOLLOW		0x02000000	/* don't follow a sym link */
 #define IN_EXCL_UNLINK		0x04000000	/* exclude events on unlinked objects */
+#define IN_MASK_CREATE		0x10000000	/* only create watches */
 #define IN_MASK_ADD		0x20000000	/* add to the mask of an already existing watch */
 #define IN_ISDIR		0x40000000	/* event occurred against dir */
 #define IN_ONESHOT		0x80000000	/* only send event once */