fanotify: store fanotify_init() flags in group's fanotify_data

This averts the need to re-generate flags in fanotify_show_fdinfo()
and sets the scene for addition of more upcoming flags without growing
new members to the fanotify_data struct.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/notify/fanotify/fanotify_user.c

@@ -191,7 +191,7 @@ static int process_access_response(struct fsnotify_group *group,
 	if (fd < 0)
 		return -EINVAL;
 
-	if ((response & FAN_AUDIT) && !group->fanotify_data.audit)
+	if ((response & FAN_AUDIT) && !FAN_GROUP_FLAG(group, FAN_ENABLE_AUDIT))
 		return -EINVAL;
 
 	event = dequeue_event(group, fd);
@@ -701,8 +701,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 	struct user_struct *user;
 	struct fanotify_event_info *oevent;
 
-	pr_debug("%s: flags=%d event_f_flags=%d\n",
-		__func__, flags, event_f_flags);
+	pr_debug("%s: flags=%x event_f_flags=%x\n",
+		 __func__, flags, event_f_flags);
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -746,6 +746,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 	}
 
 	group->fanotify_data.user = user;
+	group->fanotify_data.flags = flags;
 	atomic_inc(&user->fanotify_listeners);
 	group->memcg = get_mem_cgroup_from_mm(current->mm);
 
@@ -798,7 +799,6 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 		fd = -EPERM;
 		if (!capable(CAP_AUDIT_WRITE))
 			goto out_destroy_group;
-		group->fanotify_data.audit = true;
 	}
 
 	fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);

fs/notify/fdinfo.c

@@ -142,31 +142,9 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
 void fanotify_show_fdinfo(struct seq_file *m, struct file *f)
 {
 	struct fsnotify_group *group = f->private_data;
-	unsigned int flags = 0;
-
-	switch (group->priority) {
-	case FS_PRIO_0:
-		flags |= FAN_CLASS_NOTIF;
-		break;
-	case FS_PRIO_1:
-		flags |= FAN_CLASS_CONTENT;
-		break;
-	case FS_PRIO_2:
-		flags |= FAN_CLASS_PRE_CONTENT;
-		break;
-	}
-
-	if (group->max_events == UINT_MAX)
-		flags |= FAN_UNLIMITED_QUEUE;
-
-	if (group->fanotify_data.max_marks == UINT_MAX)
-		flags |= FAN_UNLIMITED_MARKS;
-
-	if (group->fanotify_data.audit)
-		flags |= FAN_ENABLE_AUDIT;
 
 	seq_printf(m, "fanotify flags:%x event-flags:%x\n",
-		   flags, group->fanotify_data.f_flags);
+		   group->fanotify_data.flags, group->fanotify_data.f_flags);
 
 	show_fdinfo(m, f, fanotify_fdinfo);
 }

include/linux/fanotify.h

@@ -6,4 +6,8 @@
 
 /* not valid from userspace, only kernel internal */
 #define FAN_MARK_ONDIR		0x00000100
+
+#define FAN_GROUP_FLAG(group, flag) \
+	((group)->fanotify_data.flags & (flag))
+
 #endif /* _LINUX_FANOTIFY_H */

include/linux/fsnotify_backend.h

@@ -189,10 +189,10 @@ struct fsnotify_group {
 			/* allows a group to block waiting for a userspace response */
 			struct list_head access_list;
 			wait_queue_head_t access_waitq;
-			int f_flags;
+			int flags;           /* flags from fanotify_init() */
+			int f_flags; /* event_f_flags from fanotify_init() */
 			unsigned int max_marks;
 			struct user_struct *user;
-			bool audit;
 		} fanotify_data;
 #endif /* CONFIG_FANOTIFY */
 	};