Merge tag 'fsnotify_for_v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify updates from Jan Kara:
 "Several smaller fixes and cleanups for fsnotify subsystem"

* tag 'fsnotify_for_v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fanotify: fix ignore mask logic for events on child and on dir
  fanotify: don't write with size under sizeof(response)
  fsnotify: Remove proc_fs.h include
  fanotify: remove reference to fill_event_metadata()
  fsnotify: add mutex destroy
  fanotify: prefix should_merge()
  fanotify: Replace zero-length array with flexible-array
  inotify: Fix error return code assignment flow.
  fsnotify: Add missing annotation for fsnotify_finish_user_wait() and for fsnotify_prepare_user_wait()

3 files changed, 12 insertions, 7 deletions

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index c18459cea6f4..85eda539b35f 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -70,7 +70,7 @@ static bool fanotify_name_event_equal(struct fanotify_name_event *fne1,
 	return !memcmp(fne1->name, fne2->name, fne1->name_len);
 }
 
-static bool should_merge(struct fsnotify_event *old_fsn,
+static bool fanotify_should_merge(struct fsnotify_event *old_fsn,
 			 struct fsnotify_event *new_fsn)
 {
 	struct fanotify_event *old, *new;
@@ -129,7 +129,7 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event)
 		return 0;
 
 	list_for_each_entry_reverse(test_event, list, list) {
-		if (should_merge(test_event, event)) {
+		if (fanotify_should_merge(test_event, event)) {
 			FANOTIFY_E(test_event)->mask |= new->mask;
 			return 1;
 		}
@@ -232,6 +232,10 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group,
 		if (!fsnotify_iter_should_report_type(iter_info, type))
 			continue;
 		mark = iter_info->marks[type];
+
+		/* Apply ignore mask regardless of ISDIR and ON_CHILD flags */
+		marks_ignored_mask |= mark->ignored_mask;
+
 		/*
 		 * If the event is on dir and this mark doesn't care about
 		 * events on dir, don't send it!
@@ -249,7 +253,6 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group,
 			continue;
 
 		marks_mask |= mark->mask;
-		marks_ignored_mask |= mark->ignored_mask;
 	}
 
 	test_mask = event_mask & marks_mask & ~marks_ignored_mask;
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 35bfbf4a7aac..8ce7ccfc4b0d 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -89,7 +89,7 @@ struct fanotify_name_event {
 	__kernel_fsid_t fsid;
 	struct fanotify_fh dir_fh;
 	u8 name_len;
-	char name[0];
+	char name[];
 };
 
 static inline struct fanotify_name_event *
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 42cb794c62ac..63b5dffdca9e 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -328,7 +328,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
 	ret = -EFAULT;
 	/*
 	 * Sanity check copy size in case get_one_event() and
-	 * fill_event_metadata() event_len sizes ever get out of sync.
+	 * event_len sizes ever get out of sync.
 	 */
 	if (WARN_ON_ONCE(metadata.event_len > count))
 		goto out_close_fd;
@@ -487,8 +487,10 @@ static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t
 
 	group = file->private_data;
 
-	if (count > sizeof(response))
-		count = sizeof(response);
+	if (count < sizeof(response))
+		return -EINVAL;
+
+	count = sizeof(response);
 
 	pr_debug("%s: group=%p count=%zu\n", __func__, group, count);