From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932196AbcEBSww (ORCPT ); Mon, 2 May 2016 14:52:52 -0400 Received: from g1t5424.austin.hp.com ([15.216.225.54]:52607 "EHLO g1t5424.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932105AbcEBSv4 (ORCPT ); Mon, 2 May 2016 14:51:56 -0400 From: Toshi Kani To: dan.j.williams@intel.com, jack@suse.cz, david@fromorbit.com Cc: hch@infradead.org, boaz@plexistor.com, tytso@mit.edu, adilger.kernel@dilger.ca, ross.zwisler@linux.intel.com, toshi.kani@hpe.com, micah.parrish@hpe.com, linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/3] ext2: Add alignment check for DAX mount Date: Mon, 2 May 2016 12:42:57 -0600 Message-Id: <1462214578-27122-3-git-send-email-toshi.kani@hpe.com> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1462214578-27122-1-git-send-email-toshi.kani@hpe.com> References: <1462214578-27122-1-git-send-email-toshi.kani@hpe.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Signed-off-by: Toshi Kani Cc: Jan Kara Cc: Dan Williams Cc: Ross Zwisler Cc: Christoph Hellwig Cc: Boaz Harrosh --- fs/ext2/super.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/fs/ext2/super.c b/fs/ext2/super.c index b78caf2..e636b56 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -922,14 +922,31 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); if (sbi->s_mount_opt & EXT2_MOUNT_DAX) { + struct blk_dax_ctl dax = { + .sector = 0, + .size = PAGE_SIZE, + }; if (blocksize != PAGE_SIZE) { ext2_msg(sb, KERN_ERR, "error: unsupported blocksize for dax"); goto failed_mount; } - if (!sb->s_bdev->bd_disk->fops->direct_access) { - ext2_msg(sb, KERN_ERR, + err = bdev_direct_access(sb->s_bdev, &dax); + if (err < 0) { + switch (err) { + case -EOPNOTSUPP: + ext2_msg(sb, KERN_ERR, "error: device does not support dax"); + break; + case -EINVAL: + ext2_msg(sb, KERN_ERR, + "error: unaligned partition for dax"); + break; + default: + ext2_msg(sb, KERN_ERR, + "error: dax access failed (%d)", err); + break; + } goto failed_mount; } }