Merge tag 'fsnotify_for_v6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify updates from Jan Kara:

 - reduce overhead of fsnotify infrastructure when no permission events
   are in use

 - a few small cleanups

* tag 'fsnotify_for_v6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fsnotify: fix UAF from FS_ERROR event on a shutting down filesystem
  fsnotify: optimize the case of no permission event watchers
  fsnotify: use an enum for group priority constants
  fsnotify: move s_fsnotify_connectors into fsnotify_sb_info
  fsnotify: lazy attach fsnotify_sb_info state to sb
  fsnotify: create helper fsnotify_update_sb_watchers()
  fsnotify: pass object pointer and type to fsnotify mark helpers
  fanotify: merge two checks regarding add of ignore mark
  fsnotify: create a wrapper fsnotify_find_inode_mark()
  fsnotify: create helpers to get sb and connp from object
  fsnotify: rename fsnotify_{get,put}_sb_connectors()
  fsnotify: Avoid -Wflex-array-member-not-at-end warning
  fanotify: remove unneeded sub-zero check for unsigned value

1 files changed, 22 insertions, 5 deletions

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 2fc105a72a8f..ff69ae24c4e8 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -89,11 +89,25 @@ static void fsnotify_unmount_inodes(struct super_block *sb)
 
 void fsnotify_sb_delete(struct super_block *sb)
 {
+	struct fsnotify_sb_info *sbinfo = fsnotify_sb_info(sb);
+
+	/* Were any marks ever added to any object on this sb? */
+	if (!sbinfo)
+		return;
+
 	fsnotify_unmount_inodes(sb);
 	fsnotify_clear_marks_by_sb(sb);
 	/* Wait for outstanding object references from connectors */
-	wait_var_event(&sb->s_fsnotify_connectors,
-		       !atomic_long_read(&sb->s_fsnotify_connectors));
+	wait_var_event(fsnotify_sb_watched_objects(sb),
+		       !atomic_long_read(fsnotify_sb_watched_objects(sb)));
+	WARN_ON(fsnotify_sb_has_priority_watchers(sb, FSNOTIFY_PRIO_CONTENT));
+	WARN_ON(fsnotify_sb_has_priority_watchers(sb,
+						  FSNOTIFY_PRIO_PRE_CONTENT));
+}
+
+void fsnotify_sb_free(struct super_block *sb)
+{
+	kfree(sb->s_fsnotify_info);
 }
 
 /*
@@ -489,6 +503,7 @@ int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
 {
 	const struct path *path = fsnotify_data_path(data, data_type);
 	struct super_block *sb = fsnotify_data_sb(data, data_type);
+	struct fsnotify_sb_info *sbinfo = fsnotify_sb_info(sb);
 	struct fsnotify_iter_info iter_info = {};
 	struct mount *mnt = NULL;
 	struct inode *inode2 = NULL;
@@ -525,7 +540,7 @@ int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
 	 * SRCU because we have no references to any objects and do not
 	 * need SRCU to keep them "alive".
 	 */
-	if (!sb->s_fsnotify_marks &&
+	if ((!sbinfo || !sbinfo->sb_marks) &&
 	    (!mnt || !mnt->mnt_fsnotify_marks) &&
 	    (!inode || !inode->i_fsnotify_marks) &&
 	    (!inode2 || !inode2->i_fsnotify_marks))
@@ -552,8 +567,10 @@ int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
 
 	iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu);
 
-	iter_info.marks[FSNOTIFY_ITER_TYPE_SB] =
-		fsnotify_first_mark(&sb->s_fsnotify_marks);
+	if (sbinfo) {
+		iter_info.marks[FSNOTIFY_ITER_TYPE_SB] =
+			fsnotify_first_mark(&sbinfo->sb_marks);
+	}
 	if (mnt) {
 		iter_info.marks[FSNOTIFY_ITER_TYPE_VFSMOUNT] =
 			fsnotify_first_mark(&mnt->mnt_fsnotify_marks);