fscrypt: Never allocate fscrypt_ctx on in-place encryption

In case of in-place encryption fscrypt_ctx was allocated but never
released. Since we don't need it for in-place encryption, we skip
allocating it.

Fixes: 1c7dcf69 ("fscrypt: Add in-place encryption mode")
Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/crypto/crypto.c

@@ -246,16 +246,26 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
 
 	BUG_ON(plaintext_len % FS_CRYPTO_BLOCK_SIZE != 0);
 
+	if (inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION) {
+		/* with inplace-encryption we just encrypt the page */
+		err = do_page_crypto(inode, FS_ENCRYPT, index,
+					plaintext_page, ciphertext_page,
+					plaintext_len, plaintext_offset,
+					gfp_flags);
+		if (err)
+			return ERR_PTR(err);
+
+		return ciphertext_page;
+	}
+
 	ctx = fscrypt_get_ctx(inode, gfp_flags);
 	if (IS_ERR(ctx))
 		return (struct page *)ctx;
 
-	if (!(inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION)) {
 	/* The encryption operation will require a bounce page. */
 	ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
 	if (IS_ERR(ciphertext_page))
 		goto errout;
-	}
 
 	ctx->w.control_page = plaintext_page;
 	err = do_page_crypto(inode, FS_ENCRYPT, index,
@@ -266,11 +276,9 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
 		ciphertext_page = ERR_PTR(err);
 		goto errout;
 	}
-	if (!(inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION)) {
 	SetPagePrivate(ciphertext_page);
 	set_page_private(ciphertext_page, (unsigned long)ctx);
 	lock_page(ciphertext_page);
-	}
 	return ciphertext_page;
 
 errout: