fanotify: fscking all notification system

fanotify is a novel file notification system which bases notification on
giving userspace both an event type (open, close, read, write) and an open
file descriptor to the object in question.  This should address a number of
races and problems with other notification systems like inotify and dnotify
and should allow the future implementation of blocking or access controlled
notification.  These are useful for on access scanners or hierachical storage
management schemes.

This patch just implements the basics of the fsnotify functions.

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

1 files changed, 40 insertions, 0 deletions

diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
new file mode 100644
index 000000000000..b560f86d1401
--- /dev/null
+++ b/include/linux/fanotify.h
@@ -0,0 +1,40 @@
+#ifndef _LINUX_FANOTIFY_H
+#define _LINUX_FANOTIFY_H
+
+#include <linux/types.h>
+
+/* the following events that user-space can register for */
+#define FAN_ACCESS              0x00000001      /* File was accessed */
+#define FAN_MODIFY              0x00000002      /* File was modified */
+#define FAN_CLOSE_WRITE         0x00000008      /* Unwrittable file closed */
+#define FAN_CLOSE_NOWRITE       0x00000010      /* Writtable file closed */
+#define FAN_OPEN                0x00000020      /* File was opened */
+
+#define FAN_EVENT_ON_CHILD      0x08000000      /* interested in child events */
+
+/* FIXME currently Q's have no limit.... */
+#define FAN_Q_OVERFLOW          0x00004000      /* Event queued overflowed */
+
+/* helper events */
+#define FAN_CLOSE               (FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */
+
+/*
+ * All of the events - we build the list by hand so that we can add flags in
+ * the future and not break backward compatibility.  Apps will get only the
+ * events that they originally wanted.  Be sure to add new events here!
+ */
+#define FAN_ALL_EVENTS (FAN_ACCESS |\
+                        FAN_MODIFY |\
+                        FAN_CLOSE |\
+                        FAN_OPEN)
+
+/*
+ * All legal FAN bits userspace can request (although possibly not all
+ * at the same time.
+ */
+#define FAN_ALL_INCOMING_EVENTS (FAN_ALL_EVENTS |\
+                                 FAN_EVENT_ON_CHILD)
+#ifdef __KERNEL__
+
+#endif /* __KERNEL__ */
+#endif /* _LINUX_FANOTIFY_H */