inotify: allow users to request not to recieve events on unlinked children
An inotify watch on a directory will send events for children even if those
children have been unlinked. This patch add a new inotify flag IN_EXCL_UNLINK
which allows a watch to specificy they don't care about unlinked children.
This should fix performance problems seen by tasks which add a watch to
/tmp and then are overrun with events when other processes are reading and
writing to unlinked files they created in /tmp.
https://bugzilla.kernel.org/show_bug.cgi?id=16296
Requested-by: Matthias Clasen <mclasen@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index b9b3f24..4b809fc 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -44,6 +44,7 @@
#define FS_OPEN_PERM 0x00010000 /* open event in an permission hook */
#define FS_ACCESS_PERM 0x00020000 /* access event in a permissions hook */
+#define FS_EXCL_UNLINK 0x04000000 /* do not send events if object is unlinked */
#define FS_IN_ISDIR 0x40000000 /* event occurred against dir */
#define FS_IN_ONESHOT 0x80000000 /* only send event once */