2 files changed, 16 insertions, 7 deletions

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index cf4c636ff4da..439b946c4808 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -41,6 +41,9 @@ static bool kernfs_lockdep(struct kernfs_node *kn)
 
 static int kernfs_name_locked(struct kernfs_node *kn, char *buf, size_t buflen)
 {
+	if (!kn)
+		return strlcpy(buf, "(null)", buflen);
+
 	return strlcpy(buf, kn->parent ? kn->name : "/", buflen);
 }
 
@@ -110,6 +113,8 @@ static struct kernfs_node *kernfs_common_ancestor(struct kernfs_node *a,
  * kn_to:   /n1/n2/n3         [depth=3]
  * result:  /../..
  *
+ * [3] when @kn_to is NULL result will be "(null)"
+ *
  * Returns the length of the full path.  If the full length is equal to or
  * greater than @buflen, @buf contains the truncated path with the trailing
  * '\0'.  On error, -errno is returned.
@@ -123,6 +128,9 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to,
 	size_t depth_from, depth_to, len = 0;
 	int i, j;
 
+	if (!kn_to)
+		return strlcpy(buf, "(null)", buflen);
+
 	if (!kn_from)
 		kn_from = kernfs_root(kn_to)->kn;
 
@@ -166,6 +174,8 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to,
  * similar to strlcpy().  It returns the length of @kn's name and if @buf
  * isn't long enough, it's filled upto @buflen-1 and nul terminated.
  *
+ * Fills buffer with "(null)" if @kn is NULL.
+ *
  * This function can be called from any context.
  */
 int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index 78219d5644e9..4f0535890b30 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -348,9 +348,9 @@ static void kernfs_vma_open(struct vm_area_struct *vma)
 	kernfs_put_active(of->kn);
 }
 
-static int kernfs_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+static int kernfs_vma_fault(struct vm_fault *vmf)
 {
-	struct file *file = vma->vm_file;
+	struct file *file = vmf->vma->vm_file;
 	struct kernfs_open_file *of = kernfs_of(file);
 	int ret;
 
@@ -362,16 +362,15 @@ static int kernfs_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 
 	ret = VM_FAULT_SIGBUS;
 	if (of->vm_ops->fault)
-		ret = of->vm_ops->fault(vma, vmf);
+		ret = of->vm_ops->fault(vmf);
 
 	kernfs_put_active(of->kn);
 	return ret;
 }
 
-static int kernfs_vma_page_mkwrite(struct vm_area_struct *vma,
-				   struct vm_fault *vmf)
+static int kernfs_vma_page_mkwrite(struct vm_fault *vmf)
 {
-	struct file *file = vma->vm_file;
+	struct file *file = vmf->vma->vm_file;
 	struct kernfs_open_file *of = kernfs_of(file);
 	int ret;
 
@@ -383,7 +382,7 @@ static int kernfs_vma_page_mkwrite(struct vm_area_struct *vma,
 
 	ret = 0;
 	if (of->vm_ops->page_mkwrite)
-		ret = of->vm_ops->page_mkwrite(vma, vmf);
+		ret = of->vm_ops->page_mkwrite(vmf);
 	else
 		file_update_time(file);