Merge branch 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs updates from Al Viro:
 "In this pile: pathname resolution rewrite.

   - recursion in link_path_walk() is gone.

   - nesting limits on symlinks are gone (the only limit remaining is
     that the total amount of symlinks is no more than 40, no matter how
     nested).

   - "fast" (inline) symlinks are handled without leaving rcuwalk mode.

   - stack footprint (independent of the nesting) is below kilobyte now,
     about on par with what it used to be with one level of nested
     symlinks and ~2.8 times lower than it used to be in the worst case.

   - struct nameidata is entirely private to fs/namei.c now (not even
     opaque pointers are being passed around).

   - ->follow_link() and ->put_link() calling conventions had been
     changed; all in-tree filesystems converted, out-of-tree should be
     able to follow reasonably easily.

     For out-of-tree conversions, see Documentation/filesystems/porting
     for details (and in-tree filesystems for examples of conversion).

  That has sat in -next since mid-May, seems to survive all testing
  without regressions and merges clean with v4.1"

* 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (131 commits)
  turn user_{path_at,path,lpath,path_dir}() into static inlines
  namei: move saved_nd pointer into struct nameidata
  inline user_path_create()
  inline user_path_parent()
  namei: trim do_last() arguments
  namei: stash dfd and name into nameidata
  namei: fold path_cleanup() into terminate_walk()
  namei: saner calling conventions for filename_parentat()
  namei: saner calling conventions for filename_create()
  namei: shift nameidata down into filename_parentat()
  namei: make filename_lookup() reject ERR_PTR() passed as name
  namei: shift nameidata inside filename_lookup()
  namei: move putname() call into filename_lookup()
  namei: pass the struct path to store the result down into path_lookupat()
  namei: uninline set_root{,_rcu}()
  namei: be careful with mountpoint crossings in follow_dotdot_rcu()
  Documentation: remove outdated information from automount-support.txt
  get rid of assorted nameidata-related debris
  lustre: kill unused helper
  lustre: kill unused macro (LOOKUP_CONTINUE)
  ...

1 files changed, 18 insertions, 17 deletions

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 04f124884687..308379b2d0b2 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -140,11 +140,12 @@ struct ovl_link_data {
 	void *cookie;
 };
 
-static void *ovl_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *ovl_follow_link(struct dentry *dentry, void **cookie)
 {
-	void *ret;
 	struct dentry *realdentry;
 	struct inode *realinode;
+	struct ovl_link_data *data = NULL;
+	const char *ret;
 
 	realdentry = ovl_dentry_real(dentry);
 	realinode = realdentry->d_inode;
@@ -152,28 +153,28 @@ static void *ovl_follow_link(struct dentry *dentry, struct nameidata *nd)
 	if (WARN_ON(!realinode->i_op->follow_link))
 		return ERR_PTR(-EPERM);
 
-	ret = realinode->i_op->follow_link(realdentry, nd);
-	if (IS_ERR(ret))
-		return ret;
-
 	if (realinode->i_op->put_link) {
-		struct ovl_link_data *data;
-
 		data = kmalloc(sizeof(struct ovl_link_data), GFP_KERNEL);
-		if (!data) {
-			realinode->i_op->put_link(realdentry, nd, ret);
+		if (!data)
 			return ERR_PTR(-ENOMEM);
-		}
 		data->realdentry = realdentry;
-		data->cookie = ret;
+	}
 
-		return data;
-	} else {
-		return NULL;
+	ret = realinode->i_op->follow_link(realdentry, cookie);
+	if (IS_ERR_OR_NULL(ret)) {
+		kfree(data);
+		return ret;
 	}
+
+	if (data)
+		data->cookie = *cookie;
+
+	*cookie = data;
+
+	return ret;
 }
 
-static void ovl_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
+static void ovl_put_link(struct inode *unused, void *c)
 {
 	struct inode *realinode;
 	struct ovl_link_data *data = c;
@@ -182,7 +183,7 @@ static void ovl_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
 		return;
 
 	realinode = data->realdentry->d_inode;
-	realinode->i_op->put_link(data->realdentry, nd, data->cookie);
+	realinode->i_op->put_link(realinode, data->cookie);
 	kfree(data);
 }