4 files changed, 32 insertions, 18 deletions

diff --git a/kernel/fs/kernfs/dir.c b/kernel/fs/kernfs/dir.c
index 2d48d28e1..91e004518 100644
--- a/kernel/fs/kernfs/dir.c
+++ b/kernel/fs/kernfs/dir.c
@@ -92,6 +92,29 @@ int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)
 }
 
 /**
+ * kernfs_path_len - determine the length of the full path of a given node
+ * @kn: kernfs_node of interest
+ *
+ * The returned length doesn't include the space for the terminating '\0'.
+ */
+size_t kernfs_path_len(struct kernfs_node *kn)
+{
+	size_t len = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&kernfs_rename_lock, flags);
+
+	do {
+		len += strlen(kn->name) + 1;
+		kn = kn->parent;
+	} while (kn && kn->parent);
+
+	spin_unlock_irqrestore(&kernfs_rename_lock, flags);
+
+	return len;
+}
+
+/**
  * kernfs_path - build full path of a given node
  * @kn: kernfs_node of interest
  * @buf: buffer to copy @kn's name into
diff --git a/kernel/fs/kernfs/file.c b/kernel/fs/kernfs/file.c
index 2bacb9988..7247252ee 100644
--- a/kernel/fs/kernfs/file.c
+++ b/kernel/fs/kernfs/file.c
@@ -785,7 +785,6 @@ static unsigned int kernfs_fop_poll(struct file *filp, poll_table *wait)
 	struct kernfs_node *kn = filp->f_path.dentry->d_fsdata;
 	struct kernfs_open_node *on = kn->attr.open;
 
-	/* need parent for the kobj, grab both */
 	if (!kernfs_get_active(kn))
 		goto trigger;
 
diff --git a/kernel/fs/kernfs/kernfs-internal.h b/kernel/fs/kernfs/kernfs-internal.h
index af9fa7499..6762bfbd8 100644
--- a/kernel/fs/kernfs/kernfs-internal.h
+++ b/kernel/fs/kernfs/kernfs-internal.h
@@ -76,7 +76,6 @@ extern struct kmem_cache *kernfs_node_cache;
 /*
  * inode.c
  */
-struct inode *kernfs_get_inode(struct super_block *sb, struct kernfs_node *kn);
 void kernfs_evict_inode(struct inode *inode);
 int kernfs_iop_permission(struct inode *inode, int mask);
 int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr);
diff --git a/kernel/fs/kernfs/symlink.c b/kernel/fs/kernfs/symlink.c
index 8a198898e..db272528a 100644
--- a/kernel/fs/kernfs/symlink.c
+++ b/kernel/fs/kernfs/symlink.c
@@ -112,25 +112,18 @@ static int kernfs_getlink(struct dentry *dentry, char *path)
 	return error;
 }
 
-static void *kernfs_iop_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *kernfs_iop_follow_link(struct dentry *dentry, void **cookie)
 {
 	int error = -ENOMEM;
 	unsigned long page = get_zeroed_page(GFP_KERNEL);
-	if (page) {
-		error = kernfs_getlink(dentry, (char *) page);
-		if (error < 0)
-			free_page((unsigned long)page);
-	}
-	nd_set_link(nd, error ? ERR_PTR(error) : (char *)page);
-	return NULL;
-}
-
-static void kernfs_iop_put_link(struct dentry *dentry, struct nameidata *nd,
-				void *cookie)
-{
-	char *page = nd_get_link(nd);
-	if (!IS_ERR(page))
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+	error = kernfs_getlink(dentry, (char *)page);
+	if (unlikely(error < 0)) {
 		free_page((unsigned long)page);
+		return ERR_PTR(error);
+	}
+	return *cookie = (char *)page;
 }
 
 const struct inode_operations kernfs_symlink_iops = {
@@ -140,7 +133,7 @@ const struct inode_operations kernfs_symlink_iops = {
 	.listxattr	= kernfs_iop_listxattr,
 	.readlink	= generic_readlink,
 	.follow_link	= kernfs_iop_follow_link,
-	.put_link	= kernfs_iop_put_link,
+	.put_link	= free_page_put_link,
 	.setattr	= kernfs_iop_setattr,
 	.getattr	= kernfs_iop_getattr,
 	.permission	= kernfs_iop_permission,