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  Documentation: remove outdated information from automount-support.txt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, 9 insertions, 16 deletions

diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index 8a198898e39a..db272528ab5b 100644
--- a/fs/kernfs/symlink.c
+++ b/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,