From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755348AbcECH6R (ORCPT ); Tue, 3 May 2016 03:58:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:55299 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750773AbcECH6Q (ORCPT ); Tue, 3 May 2016 03:58:16 -0400 Date: Tue, 3 May 2016 09:58:11 +0200 From: Jan Kara To: Toshi Kani Cc: dan.j.williams@intel.com, jack@suse.cz, david@fromorbit.com, hch@infradead.org, boaz@plexistor.com, tytso@mit.edu, adilger.kernel@dilger.ca, ross.zwisler@linux.intel.com, micah.parrish@hpe.com, linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/3] ext4: Add alignment check for DAX mount Message-ID: <20160503075811.GA12748@quack2.suse.cz> References: <1462214578-27122-1-git-send-email-toshi.kani@hpe.com> <1462214578-27122-2-git-send-email-toshi.kani@hpe.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1462214578-27122-2-git-send-email-toshi.kani@hpe.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 02-05-16 12:42:56, Toshi Kani wrote: > When a partition is not aligned by 4KB, mount -o dax succeeds, > but any read/write access to the filesystem fails, except for > metadata update. > > Call bdev_direct_access to check the alignment when -o dax is > specified. > > Reported-by: Micah Parrish > Signed-off-by: Toshi Kani > Cc: "Theodore Ts'o" > Cc: Andreas Dilger > Cc: Jan Kara > Cc: Dan Williams > Cc: Ross Zwisler > Cc: Christoph Hellwig > Cc: Boaz Harrosh Looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > fs/ext4/super.c | 20 ++++++++++++++++++-- > 1 file changed, 18 insertions(+), 2 deletions(-) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 304c712..51ac78e 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -3416,14 +3416,30 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) > } > > if (sbi->s_mount_opt & EXT4_MOUNT_DAX) { > + struct blk_dax_ctl dax = { > + .sector = 0, > + .size = PAGE_SIZE, > + }; > if (blocksize != PAGE_SIZE) { > ext4_msg(sb, KERN_ERR, > "error: unsupported blocksize for dax"); > goto failed_mount; > } > - if (!sb->s_bdev->bd_disk->fops->direct_access) { > - ext4_msg(sb, KERN_ERR, > + err = bdev_direct_access(sb->s_bdev, &dax); > + if (err < 0) { > + switch (err) { > + case -EOPNOTSUPP: > + ext4_msg(sb, KERN_ERR, > "error: device does not support dax"); > + break; > + case -EINVAL: > + ext4_msg(sb, KERN_ERR, > + "error: unaligned partition for dax"); > + break; > + default: > + ext4_msg(sb, KERN_ERR, > + "error: dax access failed (%d)", err); > + } > goto failed_mount; > } > } -- Jan Kara SUSE Labs, CR