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  Documentation: remove outdated information from automount-support.txt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, 15 insertions, 33 deletions

diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index 187b78920314..ba5bd18a9825 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -23,7 +23,7 @@
 #include "xattr.h"
 
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *ext4_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct page *cpage = NULL;
 	char *caddr, *paddr = NULL;
@@ -35,12 +35,9 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
 	int res;
 	u32 plen, max_size = inode->i_sb->s_blocksize;
 
-	if (!ext4_encrypted_inode(inode))
-		return page_follow_link_light(dentry, nd);
-
 	ctx = ext4_get_fname_crypto_ctx(inode, inode->i_sb->s_blocksize);
 	if (IS_ERR(ctx))
-		return ctx;
+		return ERR_CAST(ctx);
 
 	if (ext4_inode_is_fast_symlink(inode)) {
 		caddr = (char *) EXT4_I(inode)->i_data;
@@ -49,7 +46,7 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
 		cpage = read_mapping_page(inode->i_mapping, 0, NULL);
 		if (IS_ERR(cpage)) {
 			ext4_put_fname_crypto_ctx(&ctx);
-			return cpage;
+			return ERR_CAST(cpage);
 		}
 		caddr = kmap(cpage);
 		caddr[size] = 0;
@@ -80,13 +77,12 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
 	/* Null-terminate the name */
 	if (res <= plen)
 		paddr[res] = '\0';
-	nd_set_link(nd, paddr);
 	ext4_put_fname_crypto_ctx(&ctx);
 	if (cpage) {
 		kunmap(cpage);
 		page_cache_release(cpage);
 	}
-	return NULL;
+	return *cookie = paddr;
 errout:
 	ext4_put_fname_crypto_ctx(&ctx);
 	if (cpage) {
@@ -97,36 +93,22 @@ errout:
 	return ERR_PTR(res);
 }
 
-static void ext4_put_link(struct dentry *dentry, struct nameidata *nd,
-			  void *cookie)
-{
-	struct page *page = cookie;
-
-	if (!page) {
-		kfree(nd_get_link(nd));
-	} else {
-		kunmap(page);
-		page_cache_release(page);
-	}
-}
+const struct inode_operations ext4_encrypted_symlink_inode_operations = {
+	.readlink	= generic_readlink,
+	.follow_link    = ext4_follow_link,
+	.put_link       = kfree_put_link,
+	.setattr	= ext4_setattr,
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= ext4_listxattr,
+	.removexattr	= generic_removexattr,
+};
 #endif
 
-static void *ext4_follow_fast_link(struct dentry *dentry, struct nameidata *nd)
-{
-	struct ext4_inode_info *ei = EXT4_I(d_inode(dentry));
-	nd_set_link(nd, (char *) ei->i_data);
-	return NULL;
-}
-
 const struct inode_operations ext4_symlink_inode_operations = {
 	.readlink	= generic_readlink,
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-	.follow_link    = ext4_follow_link,
-	.put_link       = ext4_put_link,
-#else
 	.follow_link	= page_follow_link_light,
 	.put_link	= page_put_link,
-#endif
 	.setattr	= ext4_setattr,
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
@@ -136,7 +118,7 @@ const struct inode_operations ext4_symlink_inode_operations = {
 
 const struct inode_operations ext4_fast_symlink_inode_operations = {
 	.readlink	= generic_readlink,
-	.follow_link    = ext4_follow_fast_link,
+	.follow_link    = simple_follow_link,
 	.setattr	= ext4_setattr,
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,