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  Documentation: remove outdated information from automount-support.txt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, 13 insertions, 19 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index 47d536e59fc0..3759099d8ce4 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2451,6 +2451,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
                         return -ENOMEM;
                 }
                 inode->i_op = &shmem_short_symlink_operations;
+                inode->i_link = info->symlink;
         } else {
                 error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL);
                 if (error) {
@@ -2474,30 +2475,23 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
         return 0;
 }
 
-static void *shmem_follow_short_symlink(struct dentry *dentry, struct nameidata *nd)
-{
-        nd_set_link(nd, SHMEM_I(d_inode(dentry))->symlink);
-        return NULL;
-}
-
-static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *shmem_follow_link(struct dentry *dentry, void **cookie)
 {
         struct page *page = NULL;
         int error = shmem_getpage(d_inode(dentry), 0, &page, SGP_READ, NULL);
-        nd_set_link(nd, error ? ERR_PTR(error) : kmap(page));
-        if (page)
-                unlock_page(page);
-        return page;
+        if (error)
+                return ERR_PTR(error);
+        unlock_page(page);
+        *cookie = page;
+        return kmap(page);
 }
 
-static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
+static void shmem_put_link(struct inode *unused, void *cookie)
 {
-        if (!IS_ERR(nd_get_link(nd))) {
-                struct page *page = cookie;
-                kunmap(page);
-                mark_page_accessed(page);
-                page_cache_release(page);
-        }
+        struct page *page = cookie;
+        kunmap(page);
+        mark_page_accessed(page);
+        page_cache_release(page);
 }
 
 #ifdef CONFIG_TMPFS_XATTR
@@ -2642,7 +2636,7 @@ static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
 
 static const struct inode_operations shmem_short_symlink_operations = {
         .readlink       = generic_readlink,
-        .follow_link    = shmem_follow_short_symlink,
+        .follow_link    = simple_follow_link,
 #ifdef CONFIG_TMPFS_XATTR
         .setxattr       = shmem_setxattr,
         .getxattr       = shmem_getxattr,