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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 ADBB3C7618B for ; Tue, 23 Jul 2019 15:50:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 778732239F for ; Tue, 23 Jul 2019 15:50:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731977AbfGWPuY (ORCPT ); Tue, 23 Jul 2019 11:50:24 -0400 Received: from mx2.suse.de ([195.135.220.15]:47596 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728497AbfGWPuY (ORCPT ); Tue, 23 Jul 2019 11:50:24 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id DF2B6B0BF; Tue, 23 Jul 2019 15:50:22 +0000 (UTC) From: Luis Henriques To: Jeff Layton , Ilya Dryomov , Sage Weil Cc: ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org, Luis Henriques Subject: [RFC PATCH] ceph: fix directories inode i_blkbits initialization Date: Tue, 23 Jul 2019 16:50:20 +0100 Message-Id: <20190723155020.17338-1-lhenriques@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When filling an inode with info from the MDS, i_blkbits is being initialized using fl_stripe_unit, which contains the stripe unit in bytes. Unfortunately, this doesn't make sense for directories as they have fl_stripe_unit set to '0'. This means that i_blkbits will be set to 0xff, causing an UBSAN undefined behaviour in i_blocksize(): UBSAN: Undefined behaviour in ./include/linux/fs.h:731:12 shift exponent 255 is too large for 32-bit type 'int' Fix this by initializing i_blkbits to CEPH_BLOCK_SHIFT if fl_stripe_unit is zero. Signed-off-by: Luis Henriques --- fs/ceph/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) Hi Jeff, To be honest, I'm not sure CEPH_BLOCK_SHIFT is the right value to use here, but for sure the one currently being used isn't correct if the inode is a directory. Using stripe units seems to be a bug that has been there since the beginning, but it definitely became bigger problem after commit 69448867abcb ("fs: shave 8 bytes off of struct inode"). This fix could also be moved into the 'switch' statement later in that function, in the S_IFDIR case, similar to commit 5ba72e607cdb ("ceph: set special inode's blocksize to page size"). Let me know which version you would prefer. Cheers, -- Luis diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 791f84a13bb8..0e6d6db848b7 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -800,7 +800,12 @@ static int fill_inode(struct inode *inode, struct page *locked_page, /* update inode */ inode->i_rdev = le32_to_cpu(info->rdev); - inode->i_blkbits = fls(le32_to_cpu(info->layout.fl_stripe_unit)) - 1; + /* directories have fl_stripe_unit set to zero */ + if (le32_to_cpu(info->layout.fl_stripe_unit)) + inode->i_blkbits = + fls(le32_to_cpu(info->layout.fl_stripe_unit)) - 1; + else + inode->i_blkbits = CEPH_BLOCK_SHIFT; __ceph_update_quota(ci, iinfo->max_bytes, iinfo->max_files);