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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9215FC4321E for ; Mon, 15 Nov 2021 19:52:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 88BE461B3D for ; Mon, 15 Nov 2021 19:52:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347886AbhKOTsP (ORCPT ); Mon, 15 Nov 2021 14:48:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:44626 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245457AbhKOTUe (ORCPT ); Mon, 15 Nov 2021 14:20:34 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C882763543; Mon, 15 Nov 2021 18:35:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637001302; bh=Pr59h03XGWYuT65ux/Vp28vFAiQUb36H4exyA+ikFmM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CJGJ0oh4eRWeEyElxsclh9liqtPV9XaqyjRfZuKMImLUuwwn+POmKElez0q7T5kC7 bevO9IXApoGl6sDRE812A7jv8+VgmrbXdZg1gUyPm13wU0js7YkS1XOCqxaLYTfvj0 Q0W0hoqjNVVUZ9b029gvr2vS7h3S6q39kdlPIVrc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Miklos Szeredi , Kevin Locke Subject: [PATCH 5.15 139/917] ovl: fix filattr copy-up failure Date: Mon, 15 Nov 2021 17:53:54 +0100 Message-Id: <20211115165433.482700314@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165428.722074685@linuxfoundation.org> References: <20211115165428.722074685@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Miklos Szeredi commit 5b0a414d06c3ed2097e32ef7944a4abb644b89bd upstream. This regression can be reproduced with ntfs-3g and overlayfs: mkdir lower upper work overlay dd if=/dev/zero of=ntfs.raw bs=1M count=2 mkntfs -F ntfs.raw mount ntfs.raw lower touch lower/file.txt mount -t overlay -o lowerdir=lower,upperdir=upper,workdir=work - overlay mv overlay/file.txt overlay/file2.txt mv fails and (misleadingly) prints mv: cannot move 'overlay/file.txt' to a subdirectory of itself, 'overlay/file2.txt' The reason is that ovl_copy_fileattr() is triggered due to S_NOATIME being set on all inodes (by fuse) regardless of fileattr. ovl_copy_fileattr() tries to retrieve file attributes from lower file, but that fails because filesystem does not support this ioctl (this should fail with ENOTTY, but ntfs-3g return EINVAL instead). This failure is propagated to origial operation (in this case rename) that triggered the copy-up. The fix is to ignore ENOTTY and EINVAL errors from fileattr_get() in copy up. This also requires turning the internal ENOIOCTLCMD into ENOTTY. As a further measure to prevent unnecessary failures, only try the fileattr_get/set on upper if there are any flags to copy up. Side note: a number of filesystems set S_NOATIME (and sometimes other inode flags) irrespective of fileattr flags. This causes unnecessary calls during copy up, which might lead to a performance issue, especially if latency is high. To fix this, the kernel would need to differentiate between the two cases. E.g. introduce SB_NOATIME_UPDATE, a per-sb variant of S_NOATIME. SB_NOATIME doesn't work, because that's interpreted as "filesystem doesn't store an atime attribute" Reported-and-tested-by: Kevin Locke Fixes: 72db82115d2b ("ovl: copy up sync/noatime fileattr flags") Cc: # v5.15 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/copy_up.c | 23 ++++++++++++++++++----- fs/overlayfs/inode.c | 5 ++++- 2 files changed, 22 insertions(+), 6 deletions(-) --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -140,12 +140,14 @@ static int ovl_copy_fileattr(struct inod int err; err = ovl_real_fileattr_get(old, &oldfa); - if (err) - return err; - - err = ovl_real_fileattr_get(new, &newfa); - if (err) + if (err) { + /* Ntfs-3g returns -EINVAL for "no fileattr support" */ + if (err == -ENOTTY || err == -EINVAL) + return 0; + pr_warn("failed to retrieve lower fileattr (%pd2, err=%i)\n", + old, err); return err; + } /* * We cannot set immutable and append-only flags on upper inode, @@ -159,6 +161,17 @@ static int ovl_copy_fileattr(struct inod return err; } + /* Don't bother copying flags if none are set */ + if (!(oldfa.flags & OVL_COPY_FS_FLAGS_MASK)) + return 0; + + err = ovl_real_fileattr_get(new, &newfa); + if (err) { + pr_warn("failed to retrieve upper fileattr (%pd2, err=%i)\n", + new, err); + return err; + } + BUILD_BUG_ON(OVL_COPY_FS_FLAGS_MASK & ~FS_COMMON_FL); newfa.flags &= ~OVL_COPY_FS_FLAGS_MASK; newfa.flags |= (oldfa.flags & OVL_COPY_FS_FLAGS_MASK); --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -610,7 +610,10 @@ int ovl_real_fileattr_get(struct path *r if (err) return err; - return vfs_fileattr_get(realpath->dentry, fa); + err = vfs_fileattr_get(realpath->dentry, fa); + if (err == -ENOIOCTLCMD) + err = -ENOTTY; + return err; } int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa)