Merge tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt

Pull fscrypt updates from Ted Ts'o:
 "Refactor support for encrypted symlinks to move common code to fscrypt"

Ted also points out about the merge:
 "This makes the f2fs symlink code use the fscrypt_encrypt_symlink()
  from the fscrypt tree. This will end up dropping the kzalloc() ->
  f2fs_kzalloc() change, which means the fscrypt-specific allocation
  won't get tested by f2fs's kmalloc error injection system; which is
  fine"

* tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt: (26 commits)
  fscrypt: fix build with pre-4.6 gcc versions
  fscrypt: remove 'ci' parameter from fscrypt_put_encryption_info()
  fscrypt: document symlink length restriction
  fscrypt: fix up fscrypt_fname_encrypted_size() for internal use
  fscrypt: define fscrypt_fname_alloc_buffer() to be for presented names
  fscrypt: calculate NUL-padding length in one place only
  fscrypt: move fscrypt_symlink_data to fscrypt_private.h
  fscrypt: remove fscrypt_fname_usr_to_disk()
  ubifs: switch to fscrypt_get_symlink()
  ubifs: switch to fscrypt ->symlink() helper functions
  ubifs: free the encrypted symlink target
  f2fs: switch to fscrypt_get_symlink()
  f2fs: switch to fscrypt ->symlink() helper functions
  ext4: switch to fscrypt_get_symlink()
  ext4: switch to fscrypt ->symlink() helper functions
  fscrypt: new helper function - fscrypt_get_symlink()
  fscrypt: new helper functions for ->symlink()
  fscrypt: trim down fscrypt.h includes
  fscrypt: move fscrypt_is_dot_dotdot() to fs/crypto/fname.c
  fscrypt: move fscrypt_valid_enc_modes() to fscrypt_private.h
  ...

1 files changed, 6 insertions, 37 deletions

diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index a2006c9af1d9..dd05af983092 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -28,59 +28,28 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry,
 					   struct delayed_call *done)
 {
 	struct page *cpage = NULL;
-	char *caddr, *paddr = NULL;
-	struct fscrypt_str cstr, pstr;
-	struct fscrypt_symlink_data *sd;
-	int res;
-	u32 max_size = inode->i_sb->s_blocksize;
+	const void *caddr;
+	unsigned int max_size;
+	const char *paddr;
 
 	if (!dentry)
 		return ERR_PTR(-ECHILD);
 
-	res = fscrypt_get_encryption_info(inode);
-	if (res)
-		return ERR_PTR(res);
-
 	if (ext4_inode_is_fast_symlink(inode)) {
-		caddr = (char *) EXT4_I(inode)->i_data;
+		caddr = EXT4_I(inode)->i_data;
 		max_size = sizeof(EXT4_I(inode)->i_data);
 	} else {
 		cpage = read_mapping_page(inode->i_mapping, 0, NULL);
 		if (IS_ERR(cpage))
 			return ERR_CAST(cpage);
 		caddr = page_address(cpage);
+		max_size = inode->i_sb->s_blocksize;
 	}
 
-	/* Symlink is encrypted */
-	sd = (struct fscrypt_symlink_data *)caddr;
-	cstr.name = sd->encrypted_path;
-	cstr.len  = le16_to_cpu(sd->len);
-	if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > max_size) {
-		/* Symlink data on the disk is corrupted */
-		res = -EFSCORRUPTED;
-		goto errout;
-	}
-
-	res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
-	if (res)
-		goto errout;
-	paddr = pstr.name;
-
-	res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
-	if (res)
-		goto errout;
-
-	/* Null-terminate the name */
-	paddr[pstr.len] = '\0';
+	paddr = fscrypt_get_symlink(inode, caddr, max_size, done);
 	if (cpage)
 		put_page(cpage);
-	set_delayed_call(done, kfree_link, paddr);
 	return paddr;
-errout:
-	if (cpage)
-		put_page(cpage);
-	kfree(paddr);
-	return ERR_PTR(res);
 }
 
 const struct inode_operations ext4_encrypted_symlink_inode_operations = {