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
  ...

3 files changed, 18 insertions, 85 deletions

diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index a2ea4856e67b..9d7fb88e172e 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -1138,38 +1138,24 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
 	struct ubifs_info *c = dir->i_sb->s_fs_info;
 	int err, len = strlen(symname);
 	int sz_change = CALC_DENT_SIZE(len);
-	struct fscrypt_str disk_link = FSTR_INIT((char *)symname, len + 1);
-	struct fscrypt_symlink_data *sd = NULL;
+	struct fscrypt_str disk_link;
 	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
 					.new_ino_d = ALIGN(len, 8),
 					.dirtied_ino = 1 };
 	struct fscrypt_name nm;
 
-	if (ubifs_crypt_is_encrypted(dir)) {
-		err = fscrypt_get_encryption_info(dir);
-		if (err)
-			goto out_budg;
-
-		if (!fscrypt_has_encryption_key(dir)) {
-			err = -EPERM;
-			goto out_budg;
-		}
+	dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry,
+		symname, dir->i_ino);
 
-		disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
-				sizeof(struct fscrypt_symlink_data));
-	}
+	err = fscrypt_prepare_symlink(dir, symname, len, UBIFS_MAX_INO_DATA,
+				      &disk_link);
+	if (err)
+		return err;
 
 	/*
 	 * Budget request settings: new inode, new direntry and changing parent
 	 * directory inode.
 	 */
-
-	dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry,
-		symname, dir->i_ino);
-
-	if (disk_link.len > UBIFS_MAX_INO_DATA)
-		return -ENAMETOOLONG;
-
 	err = ubifs_budget_space(c, &req);
 	if (err)
 		return err;
@@ -1191,38 +1177,20 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
 		goto out_inode;
 	}
 
-	if (ubifs_crypt_is_encrypted(dir)) {
-		struct qstr istr = QSTR_INIT(symname, len);
-		struct fscrypt_str ostr;
-
-		sd = kzalloc(disk_link.len, GFP_NOFS);
-		if (!sd) {
-			err = -ENOMEM;
-			goto out_inode;
-		}
-
-		ostr.name = sd->encrypted_path;
-		ostr.len = disk_link.len;
-
-		err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
-		if (err) {
-			kfree(sd);
+	if (IS_ENCRYPTED(inode)) {
+		disk_link.name = ui->data; /* encrypt directly into ui->data */
+		err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
+		if (err)
 			goto out_inode;
-		}
-
-		sd->len = cpu_to_le16(ostr.len);
-		disk_link.name = (char *)sd;
 	} else {
+		memcpy(ui->data, disk_link.name, disk_link.len);
 		inode->i_link = ui->data;
 	}
 
-	memcpy(ui->data, disk_link.name, disk_link.len);
-	((char *)ui->data)[disk_link.len - 1] = '\0';
-
 	/*
 	 * The terminating zero byte is not written to the flash media and it
 	 * is put just to make later in-memory string processing simpler. Thus,
-	 * data length is @len, not @len + %1.
+	 * data length is @disk_link.len - 1, not @disk_link.len.
 	 */
 	ui->data_len = disk_link.len - 1;
 	inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1;
@@ -1240,11 +1208,10 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
 		goto out_cancel;
 	mutex_unlock(&dir_ui->ui_mutex);
 
-	ubifs_release_budget(c, &req);
 	insert_inode_hash(inode);
 	d_instantiate(dentry, inode);
-	fscrypt_free_filename(&nm);
-	return 0;
+	err = 0;
+	goto out_fname;
 
 out_cancel:
 	dir->i_size -= sz_change;
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 9fe194a4fa9b..cf348ba99238 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1629,49 +1629,17 @@ static const char *ubifs_get_link(struct dentry *dentry,
 					    struct inode *inode,
 					    struct delayed_call *done)
 {
-	int err;
-	struct fscrypt_symlink_data *sd;
 	struct ubifs_inode *ui = ubifs_inode(inode);
-	struct fscrypt_str cstr;
-	struct fscrypt_str pstr;
 
-	if (!ubifs_crypt_is_encrypted(inode))
+	if (!IS_ENCRYPTED(inode))
 		return ui->data;
 
 	if (!dentry)
 		return ERR_PTR(-ECHILD);
 
-	err = fscrypt_get_encryption_info(inode);
-	if (err)
-		return ERR_PTR(err);
-
-	sd = (struct fscrypt_symlink_data *)ui->data;
-	cstr.name = sd->encrypted_path;
-	cstr.len = le16_to_cpu(sd->len);
-
-	if (cstr.len == 0)
-		return ERR_PTR(-ENOENT);
-
-	if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > ui->data_len)
-		return ERR_PTR(-EIO);
-
-	err = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
-	if (err)
-		return ERR_PTR(err);
-
-	err = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
-	if (err) {
-		fscrypt_fname_free_buffer(&pstr);
-		return ERR_PTR(err);
-	}
-
-	pstr.name[pstr.len] = '\0';
-
-	set_delayed_call(done, kfree_link, pstr.name);
-	return pstr.name;
+	return fscrypt_get_symlink(inode, ui->data, ui->data_len, done);
 }
 
-
 const struct address_space_operations ubifs_file_address_operations = {
 	.readpage       = ubifs_readpage,
 	.writepage      = ubifs_writepage,
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 0beb285b143d..b16ef162344a 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -379,9 +379,7 @@ out:
 	}
 done:
 	clear_inode(inode);
-#ifdef CONFIG_UBIFS_FS_ENCRYPTION
-	fscrypt_put_encryption_info(inode, NULL);
-#endif
+	fscrypt_put_encryption_info(inode);
 }
 
 static void ubifs_dirty_inode(struct inode *inode, int flags)