From: "Darrick J. Wong" Subject: [PATCH] ext3: Set barrier=0 when block device does not advertise flush support Date: Thu, 2 Dec 2010 17:26:11 -0800 Message-ID: <20101203012611.GJ18195@tux1.beaverton.ibm.com> Reply-To: djwong@us.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel , linux-ext4 To: Jan Kara , Andreas Dilger , Andrew Morton Return-path: Received: from e33.co.us.ibm.com ([32.97.110.151]:49531 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758255Ab0LCB0K (ORCPT ); Thu, 2 Dec 2010 20:26:10 -0500 Content-Disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: If the user tries to enable write flushes with "barrier=1" and the underlying block device does not support flushes, print a message and set barrier=0. Signed-off-by: Darrick J. Wong --- fs/ext3/super.c | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/fs/ext3/super.c b/fs/ext3/super.c index d15209e..75ca265 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -1691,6 +1691,13 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent) NULL, 0)) goto failed_mount; + /* Catch barrier=1 and no flush support */ + if (test_opt(sb, BARRIER) && + !(sb->s_bdev->bd_disk->queue->flush_flags & REQ_FLUSH)) { + ext3_msg(sb, KERN_WARNING, "flush not supported; disabling."); + clear_opt(sbi->s_mount_opt, BARRIER); + } + sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0); @@ -2574,6 +2581,13 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data) goto restore_opts; } + /* Catch barrier=1 and no flush support */ + if (test_opt(sb, BARRIER) && + !(sb->s_bdev->bd_disk->queue->flush_flags & REQ_FLUSH)) { + ext3_msg(sb, KERN_WARNING, "flush not supported; disabling."); + clear_opt(sbi->s_mount_opt, BARRIER); + } + if (test_opt(sb, ABORT)) ext3_abort(sb, __func__, "Abort forced by user");