From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:38114 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752754AbdHBRMK (ORCPT ); Wed, 2 Aug 2017 13:12:10 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v72H9xPN036794 for ; Wed, 2 Aug 2017 13:12:10 -0400 Received: from e23smtp01.au.ibm.com (e23smtp01.au.ibm.com [202.81.31.143]) by mx0a-001b2d01.pphosted.com with ESMTP id 2c3h6qn0j6-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 02 Aug 2017 13:12:10 -0400 Received: from localhost by e23smtp01.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 3 Aug 2017 03:12:07 +1000 Subject: Re: [PATCH v4 2/5] ima: use fs method to read integrity data [updated] From: Mimi Zohar To: Jan Kara Cc: Christoph Hellwig , Al Viro , James Morris , linux-fsdevel@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, Matthew Garrett , Jan Kara , "Theodore Ts'o" , Andreas Dilger , Jaegeuk Kim , Chao Yu , Steven Whitehouse , Bob Peterson , David Woodhouse , Dave Kleikamp , Ryusuke Konishi , Mark Fasheh , Joel Becker , Richard Weinberger , "Darrick J. Wong" , Hugh Dickins , Chris Mason Date: Wed, 02 Aug 2017 13:11:52 -0400 In-Reply-To: <20170802080108.GB2732@quack2.suse.cz> References: <1501075375-29469-1-git-send-email-zohar@linux.vnet.ibm.com> <1501075375-29469-3-git-send-email-zohar@linux.vnet.ibm.com> <1501619070.3204.4.camel@linux.vnet.ibm.com> <20170802080108.GB2732@quack2.suse.cz> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Message-Id: <1501693912.20268.29.camel@linux.vnet.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, 2017-08-02 at 10:01 +0200, Jan Kara wrote: > On Tue 01-08-17 16:24:30, Mimi Zohar wrote: > > From: Christoph Hellwig > > > > Add a new ->integrity_read file operation to read data for integrity > > hash collection. This is defined to be equivalent to ->read_iter, > > except that it will be called with the i_rwsem held exclusively. > > > > Signed-off-by: Christoph Hellwig > > Cc: Matthew Garrett > > Cc: Jan Kara > > Cc: "Theodore Ts'o" > > Cc: Andreas Dilger > > Cc: Jaegeuk Kim > > Cc: Chao Yu > > Cc: Steven Whitehouse > > Cc: Bob Peterson > > Cc: David Woodhouse > > Cc: Dave Kleikamp > > Cc: Ryusuke Konishi > > Cc: Mark Fasheh > > Cc: Joel Becker > > Cc: Richard Weinberger > > Cc: "Darrick J. Wong" > > Cc: Hugh Dickins > > Cc: Chris Mason > > Signed-off-by: Mimi Zohar > > ... > > > +static ssize_t ext4_file_integrity_read_iter(struct kiocb *iocb, > > + struct iov_iter *to) > > +{ > > + struct inode *inode = file_inode(iocb->ki_filp); > > + int o_direct = iocb->ki_flags & IOCB_DIRECT; > > + > > + lockdep_assert_held(&inode->i_rwsem); > > + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) > > + return -EIO; > > + > > + if (!iov_iter_count(to)) > > + return 0; /* skip atime */ > > + > > +#ifdef CONFIG_FS_DAX > > + if (IS_DAX(inode)) > > + return dax_iomap_rw(iocb, to, &ext4_iomap_ops); > > +#endif > > + if (o_direct) > > + return -EINVAL; > > + return generic_file_read_iter(iocb, to); > > +} > > I have noticed this o_direct check - why is it only in ext4 and shouldn't > rather higher layers make sure IOCB_DIRECT iocbs cannot reach > .integrity_read() methods? This failure happens when opening a file with O_DIRECT on a block device that does not support dax (eg. loop). xfs makes it to here too, but the call to generic_file_read_iter() fails properly with -EINVAL.  (Only tested on those filesystems included that support dax (eg. ext2, ext4, and xfs).) Mimi