[PATCH 3/3] [HERE BE DRAGONS - DRAFT - __UNTESTED__] fanotify: use pidfd_file_create()

[Christian Brauner]

Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
 fs/notify/fanotify/fanotify_user.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 8f430bfad487..4a8db6b5f690 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -665,6 +665,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
 	unsigned int pidfd_mode = info_mode & FAN_REPORT_PIDFD;
 	struct file *f = NULL;
 	int ret, pidfd = FAN_NOPIDFD, fd = FAN_NOFD;
+	struct file *pidfd_file = NULL;
 
 	pr_debug("%s: group=%p event=%p\n", __func__, group, event);
 
@@ -718,9 +719,11 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
 		    !pid_has_task(event->pid, PIDTYPE_TGID)) {
 			pidfd = FAN_NOPIDFD;
 		} else {
-			pidfd = pidfd_create(event->pid, 0);
-			if (pidfd < 0)
+			pidfd_file = pidfd_file_create(event->pid, 0, &pidfd);
+			if (IS_ERR(pidfd_file)) {
 				pidfd = FAN_EPIDFD;
+				pidfd_file = NULL;
+			}
 		}
 	}
 
@@ -750,6 +753,8 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
 
 	if (f)
 		fd_install(fd, f);
+	if (pidfd_file)
+		fd_install(pidfd, pidfd_file);
 
 	return metadata.event_len;
 
@@ -759,8 +764,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
 		fput(f);
 	}
 
-	if (pidfd >= 0)
-		close_fd(pidfd);
+	if (pidfd >= 0) {
+		put_unused_fd(pidfd);
+		fput(pidfd_file);
+	}
 
 	return ret;
 }
-- 
2.34.1