From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:23679 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753628AbdHUTEu (ORCPT ); Mon, 21 Aug 2017 15:04:50 -0400 Date: Mon, 21 Aug 2017 12:00:33 -0700 From: Liu Bo To: David Sterba Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH v2] btrfs: submit superblock io with REQ_META and REQ_PRIO Message-ID: <20170821190033.GA26279@lim.localdomain> Reply-To: bo.li.liu@oracle.com References: <20170821154227.13644-1-dsterba@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170821154227.13644-1-dsterba@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Mon, Aug 21, 2017 at 05:42:27PM +0200, David Sterba wrote: > The superblock is also metadata of the filesystem so the relevant IO > should be tagged as such. We also tag it as high priority, as it's the > last block committed for metadata from a given transaction. Any delays > would effectively block the whole transaction, also blocking any other > operation holding the device_list_mutex. > Reviewed-by: Liu Bo -liubo > Signed-off-by: David Sterba > --- > fs/btrfs/disk-io.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index 90b967ae46d0..27d458640536 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -3433,9 +3433,10 @@ static int write_dev_supers(struct btrfs_device *device, > */ > if (i == 0) { > ret = btrfsic_submit_bh(REQ_OP_WRITE, > - REQ_SYNC | REQ_FUA, bh); > + REQ_SYNC | REQ_FUA | REQ_META | REQ_PRIO, bh); > } else { > - ret = btrfsic_submit_bh(REQ_OP_WRITE, REQ_SYNC, bh); > + ret = btrfsic_submit_bh(REQ_OP_WRITE, > + REQ_SYNC | REQ_META | REQ_PRIO, bh); > } > if (ret) > errors++; > -- > 2.14.0 >