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
  ...

2 files changed, 26 insertions, 108 deletions

diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 89c838bfb067..205add3d0f3a 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -585,7 +585,7 @@ no_delete:
 			!exist_written_data(sbi, inode->i_ino, ORPHAN_INO));
 	}
 out_clear:
-	fscrypt_put_encryption_info(inode, NULL);
+	fscrypt_put_encryption_info(inode);
 	clear_inode(inode);
 }
 
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index c4c94c7e9f4f..b68e7b03959f 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -486,27 +486,16 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	size_t len = strlen(symname);
-	struct fscrypt_str disk_link = FSTR_INIT((char *)symname, len + 1);
-	struct fscrypt_symlink_data *sd = NULL;
+	struct fscrypt_str disk_link;
 	int err;
 
 	if (unlikely(f2fs_cp_error(sbi)))
 		return -EIO;
 
-	if (f2fs_encrypted_inode(dir)) {
-		err = fscrypt_get_encryption_info(dir);
-		if (err)
-			return err;
-
-		if (!fscrypt_has_encryption_key(dir))
-			return -ENOKEY;
-
-		disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
-				sizeof(struct fscrypt_symlink_data));
-	}
-
-	if (disk_link.len > dir->i_sb->s_blocksize)
-		return -ENAMETOOLONG;
+	err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
+				      &disk_link);
+	if (err)
+		return err;
 
 	err = dquot_initialize(dir);
 	if (err)
@@ -516,7 +505,7 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
-	if (f2fs_encrypted_inode(inode))
+	if (IS_ENCRYPTED(inode))
 		inode->i_op = &f2fs_encrypted_symlink_inode_operations;
 	else
 		inode->i_op = &f2fs_symlink_inode_operations;
@@ -526,38 +515,13 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 	f2fs_lock_op(sbi);
 	err = f2fs_add_link(dentry, inode);
 	if (err)
-		goto out;
+		goto out_handle_failed_inode;
 	f2fs_unlock_op(sbi);
 	alloc_nid_done(sbi, inode->i_ino);
 
-	if (f2fs_encrypted_inode(inode)) {
-		struct qstr istr = QSTR_INIT(symname, len);
-		struct fscrypt_str ostr;
-
-		sd = f2fs_kzalloc(sbi, disk_link.len, GFP_NOFS);
-		if (!sd) {
-			err = -ENOMEM;
-			goto err_out;
-		}
-
-		err = fscrypt_get_encryption_info(inode);
-		if (err)
-			goto err_out;
-
-		if (!fscrypt_has_encryption_key(inode)) {
-			err = -ENOKEY;
-			goto err_out;
-		}
-
-		ostr.name = sd->encrypted_path;
-		ostr.len = disk_link.len;
-		err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
-		if (err)
-			goto err_out;
-
-		sd->len = cpu_to_le16(ostr.len);
-		disk_link.name = (char *)sd;
-	}
+	err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
+	if (err)
+		goto err_out;
 
 	err = page_symlink(inode, disk_link.name, disk_link.len);
 
@@ -584,12 +548,14 @@ err_out:
 		f2fs_unlink(dir, dentry);
 	}
 
-	kfree(sd);
-
 	f2fs_balance_fs(sbi, true);
-	return err;
-out:
+	goto out_free_encrypted_link;
+
+out_handle_failed_inode:
 	handle_failed_inode(inode);
+out_free_encrypted_link:
+	if (disk_link.name != (unsigned char *)symname)
+		kfree(disk_link.name);
 	return err;
 }
 
@@ -1148,68 +1114,20 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
 					   struct inode *inode,
 					   struct delayed_call *done)
 {
-	struct page *cpage = NULL;
-	char *caddr, *paddr = NULL;
-	struct fscrypt_str cstr = FSTR_INIT(NULL, 0);
-	struct fscrypt_str pstr = FSTR_INIT(NULL, 0);
-	struct fscrypt_symlink_data *sd;
-	u32 max_size = inode->i_sb->s_blocksize;
-	int res;
+	struct page *page;
+	const char *target;
 
 	if (!dentry)
 		return ERR_PTR(-ECHILD);
 
-	res = fscrypt_get_encryption_info(inode);
-	if (res)
-		return ERR_PTR(res);
-
-	cpage = read_mapping_page(inode->i_mapping, 0, NULL);
-	if (IS_ERR(cpage))
-		return ERR_CAST(cpage);
-	caddr = page_address(cpage);
-
-	/* Symlink is encrypted */
-	sd = (struct fscrypt_symlink_data *)caddr;
-	cstr.name = sd->encrypted_path;
-	cstr.len = le16_to_cpu(sd->len);
-
-	/* this is broken symlink case */
-	if (unlikely(cstr.len == 0)) {
-		res = -ENOENT;
-		goto errout;
-	}
-
-	if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > max_size) {
-		/* Symlink data on the disk is corrupted */
-		res = -EIO;
-		goto errout;
-	}
-	res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
-	if (res)
-		goto errout;
-
-	res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
-	if (res)
-		goto errout;
-
-	/* this is broken symlink case */
-	if (unlikely(pstr.name[0] == 0)) {
-		res = -ENOENT;
-		goto errout;
-	}
-
-	paddr = pstr.name;
-
-	/* Null-terminate the name */
-	paddr[pstr.len] = '\0';
+	page = read_mapping_page(inode->i_mapping, 0, NULL);
+	if (IS_ERR(page))
+		return ERR_CAST(page);
 
-	put_page(cpage);
-	set_delayed_call(done, kfree_link, paddr);
-	return paddr;
-errout:
-	fscrypt_fname_free_buffer(&pstr);
-	put_page(cpage);
-	return ERR_PTR(res);
+	target = fscrypt_get_symlink(inode, page_address(page),
+				     inode->i_sb->s_blocksize, done);
+	put_page(page);
+	return target;
 }
 
 const struct inode_operations f2fs_encrypted_symlink_inode_operations = {