From patchwork Mon Apr 24 17:00:13 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 9696795 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7521D603F3 for ; Mon, 24 Apr 2017 17:02:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5B53D2817F for ; Mon, 24 Apr 2017 17:02:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4E87328400; Mon, 24 Apr 2017 17:02:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AD7262817F for ; Mon, 24 Apr 2017 17:02:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S975341AbdDXRCr (ORCPT ); Mon, 24 Apr 2017 13:02:47 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:32939 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S975264AbdDXRCT (ORCPT ); Mon, 24 Apr 2017 13:02:19 -0400 Received: by mail-pg0-f67.google.com with SMTP id 63so5632707pgh.0; Mon, 24 Apr 2017 10:02:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=CP+TPnKVVtOSrrvJ7u+KOqNK8cP/OTGg4qGDC5ecKK0=; b=Z0MjW2nJWuzwThiOJ+y13hmwk9vsv1WkVvg/5+sBTLVK88RzUFFYDKGre5pNhK1Y/j ex4+zeKEWVaw7QLgwfHGhXDtse8sGMgDwY4S20QTobVve35teGA/cmRU1koHTp/tYnHa uhXRb+ybt5De1hI09JkL3egCSv2fd9oLEYztaniHHl5R2pL7ydN5XsmEsuJODraSniSw IBpgkMwGNbkFPaRqhFqEvhsXzb633l8GY0xpU45nhFN5xLzrRzc+Ed8Zp/EpwbqeIjj2 LR741PeCaMTBE3jDmfqk8ZtBBbDxpwXHhG0y4xRDvq1y2In1ldDDER45L0uCbR7iYLwj 0VRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=CP+TPnKVVtOSrrvJ7u+KOqNK8cP/OTGg4qGDC5ecKK0=; b=HDqnFL+GX90lQ+bPR7toI4PWgwiZzF8lFqaufSSAs0Hi7BlAKD8r1ykU3XqoIh8WYJ SFwWOKSPc0wCNyCeVf8sbX/J8ceTSrDeAdEh0Nhve97wVmxTxlfNcQM3vyi07MjBf2KA NAwbfmTOU2e2zQq1cD7eMZrP8b94fGqzcvcuKWpynqCKoZBWpOwQyUnq60H5w6IO6FZU FeTw4it4sTw7vY02lqZpX607eiUNbyUsYk9Z9dTzPY7Rp2r0sF/uli7VOJOIL0JALZ65 cvRSjBIcqDhcX0SnJxFB9Jlthl7MY9CpSpm9X+xvj/WOag4BhkFAQjD+Nl38e/uiQJg0 24TQ== X-Gm-Message-State: AN3rC/7pxmvEvXwQYt5x1oJhBeRBt+rAUtBnKGuaCzlnojwFaCUxjktK GWBgqtrdUUKSw6GDWZOKyQ== X-Received: by 10.99.8.193 with SMTP id 184mr25838380pgi.189.1493053338436; Mon, 24 Apr 2017 10:02:18 -0700 (PDT) Received: from ebiggers-linuxstation.kir.corp.google.com ([100.119.30.131]) by smtp.gmail.com with ESMTPSA id s89sm31927267pfi.79.2017.04.24.10.02.17 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 24 Apr 2017 10:02:17 -0700 (PDT) From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: "Theodore Y . Ts'o" , Jaegeuk Kim , linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, linux-mtd@lists.infradead.org, Gwendal Grignou , hashimoto@chromium.org, kinaba@chromium.org, Eric Biggers Subject: [PATCH 6/6] ext4: clean up ext4_match() and callers Date: Mon, 24 Apr 2017 10:00:13 -0700 Message-Id: <20170424170013.85175-7-ebiggers3@gmail.com> X-Mailer: git-send-email 2.12.2.816.g2cccc81164-goog In-Reply-To: <20170424170013.85175-1-ebiggers3@gmail.com> References: <20170424170013.85175-1-ebiggers3@gmail.com> Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Eric Biggers When ext4 encryption was originally merged, we were encrypting the user-specified filename in ext4_match(), introducing a lot of additional complexity into ext4_match() and its callers. This has since been changed to encrypt the filename earlier, so we can remove the gunk that's no longer needed. This more or less reverts ext4_search_dir() and ext4_find_dest_de() to the way they were in the v4.0 kernel. Signed-off-by: Eric Biggers --- fs/ext4/namei.c | 81 ++++++++++++++++++--------------------------------------- 1 file changed, 25 insertions(+), 56 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 6ecc3ae87a79..b6b8d073fdc4 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1237,18 +1237,17 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) } /* - * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure. + * Test whether a directory entry matches the filename being searched for. * - * `len <= EXT4_NAME_LEN' is guaranteed by caller. - * `de != NULL' is guaranteed by caller. + * Return: %true if the directory entry matches, otherwise %false. */ -static inline int ext4_match(struct ext4_filename *fname, - struct ext4_dir_entry_2 *de) +static inline bool ext4_match(const struct ext4_filename *fname, + const struct ext4_dir_entry_2 *de) { struct fscrypt_name f; if (!de->inode) - return 0; + return false; f.usr_fname = fname->usr_fname; f.disk_name = fname->disk_name; @@ -1269,48 +1268,31 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, struct ext4_dir_entry_2 * de; char * dlimit; int de_len; - int res; de = (struct ext4_dir_entry_2 *)search_buf; dlimit = search_buf + buf_size; while ((char *) de < dlimit) { /* this code is executed quadratically often */ /* do minimal checking `by hand' */ - if ((char *) de + de->name_len <= dlimit) { - res = ext4_match(fname, de); - if (res < 0) { - res = -1; - goto return_result; - } - if (res > 0) { - /* found a match - just to be sure, do - * a full check */ - if (ext4_check_dir_entry(dir, NULL, de, bh, - bh->b_data, - bh->b_size, offset)) { - res = -1; - goto return_result; - } - *res_dir = de; - res = 1; - goto return_result; - } - + if ((char *) de + de->name_len <= dlimit && + ext4_match(fname, de)) { + /* found a match - just to be sure, do + * a full check */ + if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, + bh->b_size, offset)) + return -1; + *res_dir = de; + return 1; } /* prevent looping on a bad block */ de_len = ext4_rec_len_from_disk(de->rec_len, dir->i_sb->s_blocksize); - if (de_len <= 0) { - res = -1; - goto return_result; - } + if (de_len <= 0) + return -1; offset += de_len; de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); } - - res = 0; -return_result: - return res; + return 0; } static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, @@ -1821,24 +1803,15 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode, int nlen, rlen; unsigned int offset = 0; char *top; - int res; de = (struct ext4_dir_entry_2 *)buf; top = buf + buf_size - reclen; while ((char *) de <= top) { if (ext4_check_dir_entry(dir, NULL, de, bh, - buf, buf_size, offset)) { - res = -EFSCORRUPTED; - goto return_result; - } - /* Provide crypto context and crypto buffer to ext4 match */ - res = ext4_match(fname, de); - if (res < 0) - goto return_result; - if (res > 0) { - res = -EEXIST; - goto return_result; - } + buf, buf_size, offset)) + return -EFSCORRUPTED; + if (ext4_match(fname, de)) + return -EEXIST; nlen = EXT4_DIR_REC_LEN(de->name_len); rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); if ((de->inode ? rlen - nlen : rlen) >= reclen) @@ -1846,15 +1819,11 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode, de = (struct ext4_dir_entry_2 *)((char *)de + rlen); offset += rlen; } - if ((char *) de > top) - res = -ENOSPC; - else { - *dest_de = de; - res = 0; - } -return_result: - return res; + return -ENOSPC; + + *dest_de = de; + return 0; } int ext4_insert_dentry(struct inode *dir,