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 141E6C43334 for ; Mon, 20 Jun 2022 09:37:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235965AbiFTJha (ORCPT ); Mon, 20 Jun 2022 05:37:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235491AbiFTJhM (ORCPT ); Mon, 20 Jun 2022 05:37:12 -0400 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C4E513D7C for ; Mon, 20 Jun 2022 02:37:10 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R451e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=hongnan.li@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0VGulrh2_1655717827; Received: from 30.225.24.32(mailfrom:hongnan.li@linux.alibaba.com fp:SMTPD_---0VGulrh2_1655717827) by smtp.aliyun-inc.com; Mon, 20 Jun 2022 17:37:07 +0800 Message-ID: <70fe93a3-7af5-b563-dcb7-3f7be81348ed@linux.alibaba.com> Date: Mon, 20 Jun 2022 17:37:07 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 From: hongnanLi Subject: Re: [PATCH v2] erofs: update ctx->pos for every emitted dirent To: Chao Yu , linux-erofs@lists.ozlabs.org, xiang@kernel.org Cc: linux-kernel@vger.kernel.org References: <20220527072536.68516-1-hongnan.li@linux.alibaba.com> <20220609034006.76649-1-hongnan.li@linux.alibaba.com> <0c139517-e976-5017-8e7a-d34c38f0f6bb@kernel.org> Content-Language: en-US In-Reply-To: <0c139517-e976-5017-8e7a-d34c38f0f6bb@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org on 2022/6/19 8:19, Chao Yu wrote: > On 2022/6/9 11:40, 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 | 20 ++++++++++---------- >>   1 file changed, 10 insertions(+), 10 deletions(-) >> >> diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c >> index 18e59821c597..94ef5287237a 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 +104,19 @@ static int erofs_readdir(struct file *f, struct >> dir_context *ctx) >>               initial = false; >>               ofs = roundup(ofs, sizeof(struct erofs_dirent)); >> -            if (ofs >= nameoff) >> +            if (ofs >= nameoff) { >> +                ctx->pos = blknr_to_addr(i) + ofs; >>                   goto skip_this; >> +            } >>           } >> -        err = erofs_fill_dentries(dir, ctx, de, &ofs, >> -                      nameoff, maxsize); >> -skip_this: >>           ctx->pos = blknr_to_addr(i) + ofs; > > Why updating ctx->pos before erofs_fill_dentries()? > > Thanks, It’s to ensure the ctx->pos is correct and up to date in erofs_fill_dentries() so that we can update ctx->pos instead of ofs for every emitted dirent. > >> - >> +        err = erofs_fill_dentries(dir, ctx, de, (void *)de + ofs, >> +                      nameoff, maxsize); >>           if (err) >>               break; >> +        ctx->pos = blknr_to_addr(i) + maxsize; >> +skip_this: >>           ++i; >>           ofs = 0; >>       }