inotify: move control flags from mask to mark flags

The inotify control flags in the mark mask (e.g. FS_IN_ONE_SHOT) are not
relevant to object interest mask, so move them to the mark flags.

This frees up some bits in the object interest mask.

Link: https://lore.kernel.org/r/20220422120327.3459282-3-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

3 files changed, 34 insertions, 17 deletions

diff --git a/fs/notify/inotify/inotify.h b/fs/notify/inotify/inotify.h
index 8f00151eb731..7d5df7a21539 100644
--- a/fs/notify/inotify/inotify.h
+++ b/fs/notify/inotify/inotify.h
@@ -27,11 +27,18 @@ static inline struct inotify_event_info *INOTIFY_E(struct fsnotify_event *fse)
  * userspace.  There is at least one bit (FS_EVENT_ON_CHILD) which is
  * used only internally to the kernel.
  */
-#define INOTIFY_USER_MASK (IN_ALL_EVENTS | IN_ONESHOT | IN_EXCL_UNLINK)
+#define INOTIFY_USER_MASK (IN_ALL_EVENTS)
 
 static inline __u32 inotify_mark_user_mask(struct fsnotify_mark *fsn_mark)
 {
-	return fsn_mark->mask & INOTIFY_USER_MASK;
+	__u32 mask = fsn_mark->mask & INOTIFY_USER_MASK;
+
+	if (fsn_mark->flags & FSNOTIFY_MARK_FLAG_EXCL_UNLINK)
+		mask |= IN_EXCL_UNLINK;
+	if (fsn_mark->flags & FSNOTIFY_MARK_FLAG_IN_ONESHOT)
+		mask |= IN_ONESHOT;
+
+	return mask;
 }
 
 extern void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index d92d7b0adc9a..49cfe2ae6d23 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -122,7 +122,7 @@ int inotify_handle_inode_event(struct fsnotify_mark *inode_mark, u32 mask,
 		fsnotify_destroy_event(group, fsn_event);
 	}
 
-	if (inode_mark->mask & IN_ONESHOT)
+	if (inode_mark->flags & FSNOTIFY_MARK_FLAG_IN_ONESHOT)
 		fsnotify_destroy_mark(inode_mark, group);
 
 	return 0;
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 3ef57db0ec9d..d8907d32a05b 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -115,6 +115,21 @@ static inline __u32 inotify_arg_to_mask(struct inode *inode, u32 arg)
 	return mask;
 }
 
+#define INOTIFY_MARK_FLAGS \
+	(FSNOTIFY_MARK_FLAG_EXCL_UNLINK | FSNOTIFY_MARK_FLAG_IN_ONESHOT)
+
+static inline unsigned int inotify_arg_to_flags(u32 arg)
+{
+	unsigned int flags = 0;
+
+	if (arg & IN_EXCL_UNLINK)
+		flags |= FSNOTIFY_MARK_FLAG_EXCL_UNLINK;
+	if (arg & IN_ONESHOT)
+		flags |= FSNOTIFY_MARK_FLAG_IN_ONESHOT;
+
+	return flags;
+}
+
 static inline u32 inotify_mask_to_arg(__u32 mask)
 {
 	return mask & (IN_ALL_EVENTS | IN_ISDIR | IN_UNMOUNT | IN_IGNORED |
@@ -526,13 +541,10 @@ static int inotify_update_existing_watch(struct fsnotify_group *group,
 	struct fsnotify_mark *fsn_mark;
 	struct inotify_inode_mark *i_mark;
 	__u32 old_mask, new_mask;
-	__u32 mask;
-	int add = (arg & IN_MASK_ADD);
+	int replace = !(arg & IN_MASK_ADD);
 	int create = (arg & IN_MASK_CREATE);
 	int ret;
 
-	mask = inotify_arg_to_mask(inode, arg);
-
 	fsn_mark = fsnotify_find_mark(&inode->i_fsnotify_marks, group);
 	if (!fsn_mark)
 		return -ENOENT;
@@ -545,10 +557,12 @@ static int inotify_update_existing_watch(struct fsnotify_group *group,
 
 	spin_lock(&fsn_mark->lock);
 	old_mask = fsn_mark->mask;
-	if (add)
-		fsn_mark->mask |= mask;
-	else
-		fsn_mark->mask = mask;
+	if (replace) {
+		fsn_mark->mask = 0;
+		fsn_mark->flags &= ~INOTIFY_MARK_FLAGS;
+	}
+	fsn_mark->mask |= inotify_arg_to_mask(inode, arg);
+	fsn_mark->flags |= inotify_arg_to_flags(arg);
 	new_mask = fsn_mark->mask;
 	spin_unlock(&fsn_mark->lock);
 
@@ -579,19 +593,17 @@ static int inotify_new_watch(struct fsnotify_group *group,
 			     u32 arg)
 {
 	struct inotify_inode_mark *tmp_i_mark;
-	__u32 mask;
 	int ret;
 	struct idr *idr = &group->inotify_data.idr;
 	spinlock_t *idr_lock = &group->inotify_data.idr_lock;
 
-	mask = inotify_arg_to_mask(inode, arg);
-
 	tmp_i_mark = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
 	if (unlikely(!tmp_i_mark))
 		return -ENOMEM;
 
 	fsnotify_init_mark(&tmp_i_mark->fsn_mark, group);
-	tmp_i_mark->fsn_mark.mask = mask;
+	tmp_i_mark->fsn_mark.mask = inotify_arg_to_mask(inode, arg);
+	tmp_i_mark->fsn_mark.flags = inotify_arg_to_flags(arg);
 	tmp_i_mark->wd = -1;
 
 	ret = inotify_add_to_idr(idr, idr_lock, tmp_i_mark);
@@ -845,9 +857,7 @@ static int __init inotify_user_setup(void)
 	BUILD_BUG_ON(IN_UNMOUNT != FS_UNMOUNT);
 	BUILD_BUG_ON(IN_Q_OVERFLOW != FS_Q_OVERFLOW);
 	BUILD_BUG_ON(IN_IGNORED != FS_IN_IGNORED);
-	BUILD_BUG_ON(IN_EXCL_UNLINK != FS_EXCL_UNLINK);
 	BUILD_BUG_ON(IN_ISDIR != FS_ISDIR);
-	BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT);
 
 	BUILD_BUG_ON(HWEIGHT32(ALL_INOTIFY_BITS) != 22);