7 files changed, 58 insertions, 21 deletions

diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c
index 69f42df9ba45..6624c2ee8786 100644
--- a/fs/notify/dnotify/dnotify.c
+++ b/fs/notify/dnotify/dnotify.c
@@ -65,7 +65,7 @@ static void dnotify_recalc_inode_mask(struct fsnotify_mark *fsn_mark)
         new_mask = 0;
         for (dn = dn_mark->dn; dn != NULL; dn = dn->dn_next)
                 new_mask |= (dn->dn_mask & ~FS_DN_MULTISHOT);
-        fsn_mark->mask = new_mask;
+        fsnotify_set_mark_mask_locked(fsn_mark, new_mask);
 
         if (old_mask == new_mask)
                 return;
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 84155841a025..3320f0c57e31 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -302,7 +302,7 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark, __u3
 
         spin_lock(&fsn_mark->lock);
         oldmask = fsn_mark->mask;
-        fsn_mark->mask = oldmask & ~mask;
+        fsnotify_set_mark_mask_locked(fsn_mark, (oldmask & ~mask));
         spin_unlock(&fsn_mark->lock);
 
         if (!(oldmask & ~mask))
@@ -359,7 +359,7 @@ static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark, __u32 mas
 
         spin_lock(&fsn_mark->lock);
         oldmask = fsn_mark->mask;
-        fsn_mark->mask = oldmask | mask;
+        fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask));
         spin_unlock(&fsn_mark->lock);
 
         return mask & ~oldmask;
diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h
index 204353c0f663..1be54f6f9e7d 100644
--- a/fs/notify/fsnotify.h
+++ b/fs/notify/fsnotify.h
@@ -20,6 +20,8 @@ extern __u32 fsnotify_vfsmount_mask;
 /* destroy all events sitting in this groups notification queue */
 extern void fsnotify_flush_notify(struct fsnotify_group *group);
 
+extern void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *fsn_mark,
+                                                __u32 mask);
 /* add a mark to an inode */
 extern int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
                                    struct fsnotify_group *group, struct inode *inode,
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index c925579ba011..4292f9e23ae8 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -141,7 +141,32 @@ struct fsnotify_mark *fsnotify_find_inode_mark(struct fsnotify_group *group,
 }
 
 /*
- * Attach an initialized mark mark to a given group and inode.
+ * If we are setting a mark mask on an inode mark we should pin the inode
+ * in memory.
+ */
+void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *mark,
+                                         __u32 mask)
+{
+        struct inode *inode;
+
+        assert_spin_locked(&mark->lock);
+
+        if (mask &&
+            mark->i.inode &&
+            !(mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED)) {
+                mark->flags |= FSNOTIFY_MARK_FLAG_OBJECT_PINNED;
+                inode = igrab(mark->i.inode);
+                /*
+                 * we shouldn't be able to get here if the inode wasn't
+                 * already safely held in memory.  But bug in case it
+                 * ever is wrong.
+                 */
+                BUG_ON(!inode);
+        }
+}
+
+/*
+ * Attach an initialized mark to a given group and inode.
  * These marks may be used for the fsnotify backend to determine which
  * event types should be delivered to which group and for which inodes.
  */
@@ -152,10 +177,6 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
         struct fsnotify_mark *lmark = NULL;
         int ret = 0;
 
-        inode = igrab(inode);
-        if (unlikely(!inode))
-                return -EINVAL;
-
         mark->flags = FSNOTIFY_MARK_FLAG_INODE;
 
         assert_spin_locked(&mark->lock);
@@ -175,10 +196,8 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
 
         spin_unlock(&inode->i_lock);
 
-        if (lmark) {
+        if (lmark)
                 ret = -EEXIST;
-                iput(inode);
-        }
 
         return ret;
 }
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index a12315a7553d..19d274057bfa 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -575,13 +575,11 @@ static int inotify_update_existing_watch(struct fsnotify_group *group,
         spin_lock(&fsn_mark->lock);
 
         old_mask = fsn_mark->mask;
-        if (add) {
-                fsn_mark->mask |= mask;
-                new_mask = fsn_mark->mask;
-        } else {
-                fsn_mark->mask = mask;
-                new_mask = fsn_mark->mask;
-        }
+        if (add)
+                fsnotify_set_mark_mask_locked(fsn_mark, (fsn_mark->mask | mask));
+        else
+                fsnotify_set_mark_mask_locked(fsn_mark, mask);
+        new_mask = fsn_mark->mask;
 
         spin_unlock(&fsn_mark->lock);
 
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index d296ec9ffb2a..0ebc3fd7089b 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -168,7 +168,7 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark)
          * is just a lazy update (and could be a perf win...)
          */
 
-        if (inode)
+        if (inode && (mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED))
                 iput(inode);
 
         /*
@@ -180,6 +180,17 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark)
                 fsnotify_final_destroy_group(group);
 }
 
+void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask)
+{
+        assert_spin_locked(&mark->lock);
+
+        mark->mask = mask;
+
+        if (mark->flags & FSNOTIFY_MARK_FLAG_INODE)
+                fsnotify_set_inode_mark_mask_locked(mark, mask);
+}
+
+
 /*
  * Attach an initialized mark to a given group and fs object.
  * These marks may be used for the fsnotify backend to determine which
@@ -230,6 +241,10 @@ int fsnotify_add_mark(struct fsnotify_mark *mark,
         }
 
         spin_unlock(&group->mark_lock);
+
+        /* this will pin the object if appropriate */
+        fsnotify_set_mark_mask_locked(mark, mark->mask);
+
         spin_unlock(&mark->lock);
 
         if (inode)
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 2d2f015fb700..489c881ed4ec 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -267,8 +267,9 @@ struct fsnotify_mark {
                 struct fsnotify_vfsmount_mark m;
         };
         struct list_head free_g_list;   /* tmp list used when freeing this mark */
-#define FSNOTIFY_MARK_FLAG_INODE        0x01
-#define FSNOTIFY_MARK_FLAG_VFSMOUNT     0x02
+#define FSNOTIFY_MARK_FLAG_INODE                0x01
+#define FSNOTIFY_MARK_FLAG_VFSMOUNT             0x02
+#define FSNOTIFY_MARK_FLAG_OBJECT_PINNED        0x04
         unsigned int flags;             /* vfsmount or inode mark? */
         void (*free_mark)(struct fsnotify_mark *mark); /* called on final put+free */
 };
@@ -372,6 +373,8 @@ extern struct fsnotify_mark *fsnotify_find_inode_mark(struct fsnotify_group *gro
 extern struct fsnotify_mark *fsnotify_find_vfsmount_mark(struct fsnotify_group *group, struct vfsmount *mnt);
 /* copy the values from old into new */
 extern void fsnotify_duplicate_mark(struct fsnotify_mark *new, struct fsnotify_mark *old);
+/* set the mask of a mark (might pin the object into memory */
+extern void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask);
 /* attach the mark to both the group and the inode */
 extern int fsnotify_add_mark(struct fsnotify_mark *mark, struct fsnotify_group *group,
                              struct inode *inode, struct vfsmount *mnt, int allow_dups);