fanotify: allow ignored_masks to survive modify

Some users may want to truely ignore an inode even if it has been modified.
Say you are wanting a mount which contains a log file and you really don't
want any notification about that file.  This patch allows the listener to
do that.

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

2 files changed, 5 insertions, 1 deletions

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index ad02d475770f..3e275f17e7b7 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -375,6 +375,8 @@ static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
         } else {
                 oldmask = fsn_mark->ignored_mask;
                 fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask | mask));
+                if (flags & FAN_MARK_IGNORED_SURV_MODIFY)
+                        fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY;
         }
         spin_unlock(&fsn_mark->lock);
 
diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index b8daa9f9b560..e43934d0b74c 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -31,13 +31,15 @@
 #define FAN_MARK_ONLYDIR        0x00000008
 #define FAN_MARK_MOUNT          0x00000010
 #define FAN_MARK_IGNORED_MASK   0x00000020
+#define FAN_MARK_IGNORED_SURV_MODIFY    0x00000040
 
 #define FAN_ALL_MARK_FLAGS      (FAN_MARK_ADD |\
                                  FAN_MARK_REMOVE |\
                                  FAN_MARK_DONT_FOLLOW |\
                                  FAN_MARK_ONLYDIR |\
                                  FAN_MARK_MOUNT |\
-                                 FAN_MARK_IGNORED_MASK)
+                                 FAN_MARK_IGNORED_MASK |\
+                                 FAN_MARK_IGNORED_SURV_MODIFY)
 
 /*
  * All of the events - we build the list by hand so that we can add flags in