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 X-Spam-Level: X-Spam-Status: No, score=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F402CC4743C for ; Mon, 21 Jun 2021 23:49:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5E2D611BD for ; Mon, 21 Jun 2021 23:49:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231705AbhFUXv0 (ORCPT ); Mon, 21 Jun 2021 19:51:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:42940 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231486AbhFUXv0 (ORCPT ); Mon, 21 Jun 2021 19:51:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 54F0260FF2; Mon, 21 Jun 2021 23:49:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624319351; bh=2deii/9G9YKYnTB9qWsvB4kBhJXa68gECpcH/L8ZiDM=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=qft1aP51KYdq+Strg5Egw/zINTi4IXfmeX7wvGUWNr+sK1wJlbq0V1p/b3tgpBKjo hSx98hclu/rDbrletjqKxgxsJ6xQmoKKWQtcUs4JzeU02/c2y+f1fXG44BkUMN4Mat qTu3PtCxN0VxIDh3gVPiD8gKZh2oJqlvi6kX3AsYGb2Bq9J10doHu62J42Y8dq2CJo borbq8XEszGbnETsIKYtW51uIxQA9k404ndy98uBu8kG+tBQg+ovIptOoY5ByVHrbJ tKeos8x3z0hHNt64E+eijt/6ItkNfKDvCGf/rEvZvjur5v6wR+PZrrt0UCCaxmonkL suYTGZKEiZeOw== Message-ID: Subject: Re: [PATCH] ceph: fix error handling in ceph_atomic_open and ceph_lookup From: Jeff Layton To: Ilya Dryomov Cc: Ceph Development Date: Mon, 21 Jun 2021 19:49:10 -0400 In-Reply-To: References: <20210603123850.74421-1-jlayton@kernel.org> Content-Type: text/plain; charset="ISO-8859-15" User-Agent: Evolution 3.40.2 (3.40.2-1.fc34) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org On Mon, 2021-06-21 at 21:20 +0200, Ilya Dryomov wrote: > On Thu, Jun 3, 2021 at 2:38 PM Jeff Layton wrote: > > > > Commit aa60cfc3f7ee broke the error handling in these functions such > > that they don't handle non-ENOENT errors from ceph_mdsc_do_request > > properly. > > > > Move the checking of -ENOENT out of ceph_handle_snapdir and into the > > callers, and if we get a different error, return it immediately. > > > > Fixes: aa60cfc3f7ee ("ceph: don't use d_add in ceph_handle_snapdir") > > Signed-off-by: Jeff Layton > > --- > > fs/ceph/dir.c | 17 ++++++----------- > > fs/ceph/file.c | 6 +++--- > > fs/ceph/super.h | 2 +- > > 3 files changed, 10 insertions(+), 15 deletions(-) > > > > diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c > > index 5624fae7a603..ac431246e0c9 100644 > > --- a/fs/ceph/dir.c > > +++ b/fs/ceph/dir.c > > @@ -668,14 +668,13 @@ static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence) > > * Handle lookups for the hidden .snap directory. > > */ > > struct dentry *ceph_handle_snapdir(struct ceph_mds_request *req, > > - struct dentry *dentry, int err) > > + struct dentry *dentry) > > { > > struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb); > > struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */ > > > > /* .snap dir? */ > > - if (err == -ENOENT && > > - ceph_snap(parent) == CEPH_NOSNAP && > > + if (ceph_snap(parent) == CEPH_NOSNAP && > > strcmp(dentry->d_name.name, fsc->mount_options->snapdir_name) == 0) { > > struct dentry *res; > > struct inode *inode = ceph_get_snapdir(parent); > > @@ -742,7 +741,6 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry, > > struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb); > > struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb); > > struct ceph_mds_request *req; > > - struct dentry *res; > > int op; > > int mask; > > int err; > > @@ -793,13 +791,10 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry, > > req->r_parent = dir; > > set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags); > > err = ceph_mdsc_do_request(mdsc, NULL, req); > > - res = ceph_handle_snapdir(req, dentry, err); > > - if (IS_ERR(res)) { > > - err = PTR_ERR(res); > > - } else { > > - dentry = res; > > - err = 0; > > - } > > + if (err == -ENOENT) > > + dentry = ceph_handle_snapdir(req, dentry); > > + if (IS_ERR(dentry)) > > + err = PTR_ERR(dentry); > > dentry = ceph_finish_lookup(req, dentry, err); > > ceph_mdsc_put_request(req); /* will dput(dentry) */ > > dout("lookup result=%p\n", dentry); > > diff --git a/fs/ceph/file.c b/fs/ceph/file.c > > index 7aa20d50a231..a01ad342a91d 100644 > > --- a/fs/ceph/file.c > > +++ b/fs/ceph/file.c > > @@ -739,14 +739,14 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry, > > err = ceph_mdsc_do_request(mdsc, > > (flags & (O_CREAT|O_TRUNC)) ? dir : NULL, > > req); > > - dentry = ceph_handle_snapdir(req, dentry, err); > > + if (err == -ENOENT) > > + dentry = ceph_handle_snapdir(req, dentry); > > if (IS_ERR(dentry)) { > > err = PTR_ERR(dentry); > > goto out_req; > > } > > Hi Jeff, > > This doesn't seem right to me. Looking at 5.12, ENOENT from > ceph_mdsc_do_request() could be resolved by ceph_handle_snapdir() > meaning that ceph_handle_notrace_create() could be called and > ceph_finish_lookup() could be passed err == 0. > > With this patch err would remain ENOENT, resulting in skipping > the potential ceph_handle_notrace_create() call and passing that > ENOENT to ceph_finish_lookup(). > Well spotted! I have a v2 version that I'm running through xfstests now. I'll send it along in a bit. Thanks! -- Jeff Layton