8 files changed, 145 insertions, 0 deletions

diff --git a/fs/notify/Kconfig b/fs/notify/Kconfig
index dffbb0911d02..22c629eedd82 100644
--- a/fs/notify/Kconfig
+++ b/fs/notify/Kconfig
@@ -3,3 +3,4 @@ config FSNOTIFY
 
 source "fs/notify/dnotify/Kconfig"
 source "fs/notify/inotify/Kconfig"
+source "fs/notify/fanotify/Kconfig"
diff --git a/fs/notify/Makefile b/fs/notify/Makefile
index 0922cc826c46..396a38779371 100644
--- a/fs/notify/Makefile
+++ b/fs/notify/Makefile
@@ -2,3 +2,4 @@ obj-$(CONFIG_FSNOTIFY)		+= fsnotify.o notification.o group.o inode_mark.o
 
 obj-y                   += dnotify/
 obj-y                   += inotify/
+obj-y                   += fanotify/
diff --git a/fs/notify/fanotify/Kconfig b/fs/notify/fanotify/Kconfig
new file mode 100644
index 000000000000..f9d7ae081f85
--- /dev/null
+++ b/fs/notify/fanotify/Kconfig
@@ -0,0 +1,11 @@
+config FANOTIFY
+        bool "Filesystem wide access notification"
+        select FSNOTIFY
+        default y
+        ---help---
+           Say Y here to enable fanotify suport.  fanotify is a file access
+           notification system which differs from inotify in that it sends
+           and open file descriptor to the userspace listener along with
+           the event.
+
+           If unsure, say Y.
diff --git a/fs/notify/fanotify/Makefile b/fs/notify/fanotify/Makefile
new file mode 100644
index 000000000000..e7d39c05b0fe
--- /dev/null
+++ b/fs/notify/fanotify/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_FANOTIFY)          += fanotify.o
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
new file mode 100644
index 000000000000..3ffb9dbcab08
--- /dev/null
+++ b/fs/notify/fanotify/fanotify.c
@@ -0,0 +1,78 @@
+#include <linux/fdtable.h>
+#include <linux/fsnotify_backend.h>
+#include <linux/init.h>
+#include <linux/kernel.h> /* UINT_MAX */
+#include <linux/types.h>
+
+#include "fanotify.h"
+
+static int fanotify_handle_event(struct fsnotify_group *group, struct fsnotify_event *event)
+{
+        int ret;
+
+
+        BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS);
+        BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY);
+        BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
+        BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE);
+        BUILD_BUG_ON(FAN_OPEN != FS_OPEN);
+        BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD);
+        BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW);
+
+        pr_debug("%s: group=%p event=%p\n", __func__, group, event);
+
+        ret = fsnotify_add_notify_event(group, event, NULL, NULL);
+
+        return ret;
+}
+
+static bool fanotify_should_send_event(struct fsnotify_group *group, struct inode *inode,
+                                       struct vfsmount *mnt, __u32 mask, void *data,
+                                       int data_type)
+{
+        struct fsnotify_mark *fsn_mark;
+        bool send;
+
+        pr_debug("%s: group=%p inode=%p mask=%x data=%p data_type=%d\n",
+                 __func__, group, inode, mask, data, data_type);
+
+        /* sorry, fanotify only gives a damn about files and dirs */
+        if (!S_ISREG(inode->i_mode) &&
+            !S_ISDIR(inode->i_mode))
+                return false;
+
+        /* if we don't have enough info to send an event to userspace say no */
+        if (data_type != FSNOTIFY_EVENT_PATH)
+                return false;
+
+        fsn_mark = fsnotify_find_mark(group, inode);
+        if (!fsn_mark)
+                return false;
+
+        /* if the event is for a child and this inode doesn't care about
+         * events on the child, don't send it! */
+        if ((mask & FS_EVENT_ON_CHILD) &&
+            !(fsn_mark->mask & FS_EVENT_ON_CHILD)) {
+                send = false;
+        } else {
+                /*
+                 * We care about children, but do we care about this particular
+                 * type of event?
+                 */
+                mask = (mask & ~FS_EVENT_ON_CHILD);
+                send = (fsn_mark->mask & mask);
+        }
+
+        /* find took a reference */
+        fsnotify_put_mark(fsn_mark);
+
+        return send;
+}
+
+const struct fsnotify_ops fanotify_fsnotify_ops = {
+        .handle_event = fanotify_handle_event,
+        .should_send_event = fanotify_should_send_event,
+        .free_group_priv = NULL,
+        .free_event_priv = NULL,
+        .freeing_mark = NULL,
+};
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
new file mode 100644
index 000000000000..50765eb30fe4
--- /dev/null
+++ b/fs/notify/fanotify/fanotify.h
@@ -0,0 +1,12 @@
+#include <linux/fanotify.h>
+#include <linux/fsnotify_backend.h>
+#include <linux/net.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+static inline bool fanotify_mask_valid(__u32 mask)
+{
+        if (mask & ~((__u32)FAN_ALL_INCOMING_EVENTS))
+                return false;
+        return true;
+}
diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index 2fc8e14cc24a..d5cca9a05f14 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -210,6 +210,7 @@ unifdef-y += ethtool.h
 unifdef-y += eventpoll.h
 unifdef-y += signalfd.h
 unifdef-y += ext2_fs.h
+unifdef-y += fanotify.h
 unifdef-y += fb.h
 unifdef-y += fcntl.h
 unifdef-y += filter.h
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 */