6 files changed, 53 insertions, 19 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)