From patchwork Thu Aug 15 04:41:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gao Xiang X-Patchwork-Id: 11095043 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 254791398 for ; Thu, 15 Aug 2019 04:44:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 15283285AD for ; Thu, 15 Aug 2019 04:44:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 097E02888E; Thu, 15 Aug 2019 04:44:32 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI 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 8128B285EE for ; Thu, 15 Aug 2019 04:44:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730330AbfHOEo0 (ORCPT ); Thu, 15 Aug 2019 00:44:26 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:35368 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729916AbfHOEm4 (ORCPT ); Thu, 15 Aug 2019 00:42:56 -0400 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 3540AB91C6CCBF4D703A; Thu, 15 Aug 2019 12:42:48 +0800 (CST) Received: from architecture4.huawei.com (10.140.130.215) by smtp.huawei.com (10.3.19.210) with Microsoft SMTP Server (TLS) id 14.3.439.0; Thu, 15 Aug 2019 12:42:39 +0800 From: Gao Xiang To: , , "Alexander Viro" CC: LKML , Greg Kroah-Hartman , Andrew Morton , Stephen Rothwell , Theodore Ts'o , Pavel Machek , David Sterba , "Amir Goldstein" , Christoph Hellwig , "Darrick J . Wong" , Dave Chinner , Jaegeuk Kim , Jan Kara , Richard Weinberger , Linus Torvalds , , Chao Yu , Miao Xie , Li Guifu , Fang Wei , Gao Xiang Subject: [PATCH v8 07/24] erofs: add directory operations Date: Thu, 15 Aug 2019 12:41:38 +0800 Message-ID: <20190815044155.88483-8-gaoxiang25@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190815044155.88483-1-gaoxiang25@huawei.com> References: <20190815044155.88483-1-gaoxiang25@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.140.130.215] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This adds functions for directory, mainly readdir. Signed-off-by: Gao Xiang --- fs/erofs/dir.c | 148 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 fs/erofs/dir.c diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c new file mode 100644 index 000000000000..c52d27bedff4 --- /dev/null +++ b/fs/erofs/dir.c @@ -0,0 +1,148 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/fs/erofs/dir.c + * + * Copyright (C) 2017-2018 HUAWEI, Inc. + * http://www.huawei.com/ + * Created by Gao Xiang + */ +#include "internal.h" + +static const unsigned char erofs_filetype_table[EROFS_FT_MAX] = { + [EROFS_FT_UNKNOWN] = DT_UNKNOWN, + [EROFS_FT_REG_FILE] = DT_REG, + [EROFS_FT_DIR] = DT_DIR, + [EROFS_FT_CHRDEV] = DT_CHR, + [EROFS_FT_BLKDEV] = DT_BLK, + [EROFS_FT_FIFO] = DT_FIFO, + [EROFS_FT_SOCK] = DT_SOCK, + [EROFS_FT_SYMLINK] = DT_LNK, +}; + +static void debug_one_dentry(unsigned char d_type, const char *de_name, + unsigned int de_namelen) +{ +#ifdef CONFIG_EROFS_FS_DEBUG + /* since the on-disk name could not have the trailing '\0' */ + unsigned char dbg_namebuf[EROFS_NAME_LEN + 1]; + + memcpy(dbg_namebuf, de_name, de_namelen); + dbg_namebuf[de_namelen] = '\0'; + + debugln("found dirent %s de_len %u d_type %d", dbg_namebuf, + de_namelen, d_type); +#endif +} + +static int erofs_fill_dentries(struct inode *dir, struct dir_context *ctx, + void *dentry_blk, unsigned int *ofs, + unsigned int nameoff, unsigned int maxsize) +{ + struct erofs_dirent *de = dentry_blk + *ofs; + const struct erofs_dirent *end = dentry_blk + nameoff; + + while (de < end) { + const char *de_name; + unsigned int de_namelen; + unsigned char d_type; + + if (de->file_type < EROFS_FT_MAX) + d_type = erofs_filetype_table[de->file_type]; + else + d_type = DT_UNKNOWN; + + nameoff = le16_to_cpu(de->nameoff); + de_name = (char *)dentry_blk + nameoff; + + /* the last dirent in the block? */ + if (de + 1 >= end) + de_namelen = strnlen(de_name, maxsize - nameoff); + else + de_namelen = le16_to_cpu(de[1].nameoff) - nameoff; + + /* a corrupted entry is found */ + if (unlikely(nameoff + de_namelen > maxsize || + de_namelen > EROFS_NAME_LEN)) { + errln("bogus dirent @ nid %llu", EROFS_V(dir)->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; + } + + debug_one_dentry(d_type, de_name, de_namelen); + if (!dir_emit(ctx, de_name, de_namelen, + le64_to_cpu(de->nid), d_type)) + /* stopped by some reason */ + return 1; + ++de; + *ofs += sizeof(struct erofs_dirent); + } + *ofs = maxsize; + return 0; +} + +static int erofs_readdir(struct file *f, struct dir_context *ctx) +{ + struct inode *dir = file_inode(f); + struct address_space *mapping = dir->i_mapping; + const size_t dirsize = i_size_read(dir); + unsigned int i = ctx->pos / EROFS_BLKSIZ; + unsigned int ofs = ctx->pos % EROFS_BLKSIZ; + int err = 0; + bool initial = true; + + while (ctx->pos < dirsize) { + struct page *dentry_page; + struct erofs_dirent *de; + unsigned int nameoff, maxsize; + + dentry_page = read_mapping_page(mapping, i, NULL); + if (IS_ERR(dentry_page)) + continue; + + de = (struct erofs_dirent *)kmap(dentry_page); + + nameoff = le16_to_cpu(de->nameoff); + + if (unlikely(nameoff < sizeof(struct erofs_dirent) || + nameoff >= PAGE_SIZE)) { + errln("%s, invalid de[0].nameoff %u @ nid %llu", + __func__, nameoff, EROFS_V(dir)->nid); + err = -EFSCORRUPTED; + goto skip_this; + } + + maxsize = min_t(unsigned int, + dirsize - ctx->pos + ofs, PAGE_SIZE); + + /* search dirents at the arbitrary position */ + if (unlikely(initial)) { + initial = false; + + ofs = roundup(ofs, sizeof(struct erofs_dirent)); + if (unlikely(ofs >= nameoff)) + goto skip_this; + } + + err = erofs_fill_dentries(dir, ctx, de, &ofs, + nameoff, maxsize); +skip_this: + kunmap(dentry_page); + + put_page(dentry_page); + + ctx->pos = blknr_to_addr(i) + ofs; + + if (unlikely(err)) + break; + ++i; + ofs = 0; + } + return err < 0 ? err : 0; +} + +const struct file_operations erofs_dir_fops = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .iterate_shared = erofs_readdir, +}; +