fsnotify/vfsmount: add fsnotify fields to struct vfsmount

This patch adds the list and mask fields needed to support vfsmount marks.
These are the same fields fsnotify needs on an inode.  They are not used,
just declared and we note where the cleanup hook should be (the function is
not yet defined)

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Eric Paris <eparis@redhat.com>

3 files changed, 10 insertions, 4 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index 88058de59c7c..a2d681a6b5e9 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -29,6 +29,7 @@
 #include <linux/log2.h>
 #include <linux/idr.h>
 #include <linux/fs_struct.h>
+#include <linux/fsnotify.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include "pnode.h"
@@ -150,6 +151,9 @@ struct vfsmount *alloc_vfsmnt(const char *name)
                 INIT_LIST_HEAD(&mnt->mnt_share);
                 INIT_LIST_HEAD(&mnt->mnt_slave_list);
                 INIT_LIST_HEAD(&mnt->mnt_slave);
+#ifdef CONFIG_FSNOTIFY
+                INIT_HLIST_HEAD(&mnt->mnt_fsnotify_marks);
+#endif
 #ifdef CONFIG_SMP
                 mnt->mnt_writers = alloc_percpu(int);
                 if (!mnt->mnt_writers)
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 60e84fd338dd..e0bf86953e1b 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -163,9 +163,7 @@ static bool needed_by_vfsmount(__u32 test_mask, struct vfsmount *mnt)
         if (!mnt)
                 return false;
 
-        /* hook in this when mnt->mnt_fsnotify_mask is defined */
-        /* return (test_mask & path->mnt->mnt_fsnotify_mask); */
-        return false;
+        return (test_mask & mnt->mnt_fsnotify_mask);
 }
 /*
  * This is the main call to fsnotify.  The VFS calls into hook specific functions
diff --git a/include/linux/mount.h b/include/linux/mount.h
index 4bd05474d11d..907210bd9f9c 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -56,7 +56,11 @@ struct vfsmount {
         struct list_head mnt_mounts;    /* list of children, anchored here */
         struct list_head mnt_child;     /* and going through their mnt_child */
         int mnt_flags;
-        /* 4 bytes hole on 64bits arches */
+        /* 4 bytes hole on 64bits arches without fsnotify */
+#ifdef CONFIG_FSNOTIFY
+        __u32 mnt_fsnotify_mask;
+        struct hlist_head mnt_fsnotify_marks;
+#endif
         const char *mnt_devname;        /* Name of device e.g. /dev/dsk/hda1 */
         struct list_head mnt_list;
         struct list_head mnt_expire;    /* link in fs-specific expiry list */