From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22048C43334 for ; Fri, 22 Jul 2022 08:16:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234611AbiGVIQf (ORCPT ); Fri, 22 Jul 2022 04:16:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233544AbiGVIQe (ORCPT ); Fri, 22 Jul 2022 04:16:34 -0400 Received: from out30-42.freemail.mail.aliyun.com (out30-42.freemail.mail.aliyun.com [115.124.30.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C1705245B for ; Fri, 22 Jul 2022 01:16:30 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04400;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0VK4F-Js_1658477787; Received: from 30.227.66.15(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0VK4F-Js_1658477787) by smtp.aliyun-inc.com; Fri, 22 Jul 2022 16:16:27 +0800 Message-ID: Date: Fri, 22 Jul 2022 16:16:26 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v3] erofs: update ctx->pos for every emitted dirent Content-Language: en-US To: Hongnan Li , linux-erofs@lists.ozlabs.org, xiang@kernel.org, chao@kernel.org Cc: linux-kernel@vger.kernel.org References: <20220527072536.68516-1-hongnan.li@linux.alibaba.com> <20220629081550.23501-1-hongnan.li@linux.alibaba.com> From: JeffleXu In-Reply-To: <20220629081550.23501-1-hongnan.li@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The patch itself looks good to me. On 6/29/22 4:15 PM, Hongnan Li wrote: > erofs_readdir update ctx->pos after filling a batch of dentries > and it may cause dir/files duplication for NFS readdirplus which > depends on ctx->pos to fill dir correctly. So update ctx->pos for > every emitted dirent in erofs_fill_dentries to fix it. > > Fixes: 3e917cc305c6 ("erofs: make filesystem exportable") > Signed-off-by: Hongnan Li > --- > fs/erofs/dir.c | 16 +++++++--------- > 1 file changed, 7 insertions(+), 9 deletions(-) > > diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c > index 18e59821c597..6fc325052853 100644 > --- a/fs/erofs/dir.c > +++ b/fs/erofs/dir.c > @@ -22,10 +22,9 @@ static void debug_one_dentry(unsigned char d_type, const char *de_name, > } > > static int erofs_fill_dentries(struct inode *dir, struct dir_context *ctx, > - void *dentry_blk, unsigned int *ofs, > + void *dentry_blk, struct erofs_dirent *de, > unsigned int nameoff, unsigned int maxsize) > { > - struct erofs_dirent *de = dentry_blk + *ofs; > const struct erofs_dirent *end = dentry_blk + nameoff; > > while (de < end) { > @@ -59,9 +58,8 @@ static int erofs_fill_dentries(struct inode *dir, struct dir_context *ctx, > /* stopped by some reason */ > return 1; > ++de; > - *ofs += sizeof(struct erofs_dirent); > + ctx->pos += sizeof(struct erofs_dirent); > } > - *ofs = maxsize; > return 0; > } > > @@ -95,7 +93,7 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx) > "invalid de[0].nameoff %u @ nid %llu", > nameoff, EROFS_I(dir)->nid); > err = -EFSCORRUPTED; > - goto skip_this; > + break; > } > > maxsize = min_t(unsigned int, > @@ -106,17 +104,17 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx) > initial = false; > > ofs = roundup(ofs, sizeof(struct erofs_dirent)); > + ctx->pos = blknr_to_addr(i) + ofs; > if (ofs >= nameoff) > goto skip_this; Besides, I thinks there's another issue with erofs_readdir() here (though unrelated to the issue this patch wants to fix). We need to update ctx->pos correctly if the initial file position has exceeded nameoff. ctx->pos needs to be updated to the end of EROFS_BLKSIZ or directory's i_size, surpassing the remaining name string in the current EROFS block. > } > > - err = erofs_fill_dentries(dir, ctx, de, &ofs, > + err = erofs_fill_dentries(dir, ctx, de, (void *)de + ofs, > nameoff, maxsize); > -skip_this: > - ctx->pos = blknr_to_addr(i) + ofs; > - > if (err) > break; > + ctx->pos = blknr_to_addr(i) + maxsize; It's quite easy to fix the above issue. We only need to move this line beneath skip_this label. > +skip_this:> ++i; > ofs = 0; > } like: skip_this: ctx->pos = blknr_to_addr(i) + maxsize; ++i; ofs = 0; Thus we'd better fold this simple fix into this patch. -- Thanks, Jeffle