fanotify: send tgid with notification messages

From: Eric Paris <eparis@redhat.com>

Send tgid of original process to fanotify listeners

Signed-off-by: Eric Paris <eparis@redhat.com>
---

 fs/notify/fanotify.h          |    1 +
 fs/notify/notification.c      |    1 +
 fs/notify/notification_user.c |    9 +++++----
 3 files changed, 7 insertions(+), 4 deletions(-)


diff --git a/fs/notify/fanotify.h b/fs/notify/fanotify.h
index 1550472..f89ff19 100644
--- a/fs/notify/fanotify.h
+++ b/fs/notify/fanotify.h
@@ -76,6 +76,7 @@ struct fanotify_event {
 	/* if waiting for a userspace access answer this is the cookie they will send back */
 	unsigned long cookie;
 	pid_t pid;		/* pid of the original process */
+	pid_t tgid;		/* tgid of the original process */
 	spinlock_t response_lock; /* protects response */
 	unsigned int response;	/* userspace answer to question */
 };
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 37b57dd..9ab29bf 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -146,6 +146,7 @@ struct fanotify_event *create_event(struct file *file, unsigned int mask)
 	event->mask = mask;
 
 	event->pid = current->pid;
+	event->tgid = current->tgid;
 
 	WARN_ON(!event->path.dentry);
 	WARN_ON(!event->path.mnt);
diff --git a/fs/notify/notification_user.c b/fs/notify/notification_user.c
index b7b08d3..48f201d 100644
--- a/fs/notify/notification_user.c
+++ b/fs/notify/notification_user.c
@@ -48,12 +48,13 @@
  * "mask=%x "	= 14 characters
  * "cookie=%lu "= 27 characters
  * "pid=%d "	= 16 characters
+ * "tgid=%d "	= 17 characters
  * "\n "	=  2 characters
  * NULL		=  1 character
  * 
- * MAX_MESG_LEN = 75
+ * MAX_MESG_LEN = 92
  */
-#define MAX_MESG_LEN 75
+#define MAX_MESG_LEN 92
 
 static ssize_t fanotify_notification_read(struct file *file, char __user *buf, size_t lenp, loff_t *offset)
 {
@@ -134,8 +135,8 @@ static ssize_t fanotify_notification_read(struct file *file, char __user *buf, s
 	 * Build metadata string to send to the listener
 	 * IF YOU CHANGE THIS STRING UPDATE MAX_MSG_LEN!!!!!!11111!!!!
 	 */
-	rc = snprintf(output, lenp-1, "fd=%d mask=%x cookie=%lu pid=%d\n",
-		      client_fd, event->mask, event->cookie, event->pid);
+	rc = snprintf(output, lenp-1, "fd=%d mask=%x cookie=%lu pid=%d tgid=%d\n",
+		      client_fd, event->mask, event->cookie, event->pid, event->tgid);
 	if (rc < 0)
 		goto out;
 	output[rc] = '\0';