fsnotify: report FS_ISDIR flag with MOVE_SELF and DELETE_SELF events

We need to report FS_ISDIR flag with MOVE_SELF and DELETE_SELF events
for fanotify, because fanotify API requires the user to explicitly
request events on directories by FAN_ONDIR flag.

inotify never reported IN_ISDIR with those events. It looks like an
oversight, but to avoid the risk of breaking existing inotify programs,
mask the FS_ISDIR flag out when reprting those events to inotify backend.

We also add the FS_ISDIR flag with FS_ATTRIB event in the case of rename
over an empty target directory. inotify did not report IN_ISDIR in this
case, but it normally does report IN_ISDIR along with IN_ATTRIB event,
so in this case, we do not mask out the FS_ISDIR flag.

[JK: Simplify the checks in fsnotify_move()]

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 9 insertions, 0 deletions

diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index fe97299975f2..ff30abd6a49b 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -113,6 +113,15 @@ int inotify_handle_event(struct fsnotify_group *group,
                 return -ENOMEM;
         }
 
+        /*
+         * We now report FS_ISDIR flag with MOVE_SELF and DELETE_SELF events
+         * for fanotify. inotify never reported IN_ISDIR with those events.
+         * It looks like an oversight, but to avoid the risk of breaking
+         * existing inotify programs, mask the flag out from those events.
+         */
+        if (mask & (IN_MOVE_SELF | IN_DELETE_SELF))
+                mask &= ~IN_ISDIR;
+
         fsn_event = &event->fse;
         fsnotify_init_event(fsn_event, inode);
         event->mask = mask;