From: Johannes Thumshirn <jthumshirn@suse.de>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Max Gurtovoy <maxg@mellanox.com>,
Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
Christoph Hellwig <hch@lst.de>,
Linux Kernel Mailinglist <linux-kernel@vger.kernel.org>,
Linux NVMe Mailinglist <linux-nvme@lists.infradead.org>
Subject: Re: [PATCH] nvmet: disable direct I/O when unavailable
Date: Mon, 25 Feb 2019 16:38:27 +0100 [thread overview]
Message-ID: <20190225153827.GA17442@linux-x5ow.site> (raw)
In-Reply-To: <a85e85d6-6a06-7663-3a12-710b6467dedd@acm.org>
On Mon, Feb 25, 2019 at 06:49:04AM -0800, Bart Van Assche wrote:
> On 2/25/19 1:37 AM, Johannes Thumshirn wrote:
> > On 24/02/2019 11:54, Max Gurtovoy wrote:
> > > What is the status of iSCSI/SRP targets in this case ?
> >
> > iSCSI/SRP passes in the following:
> >
> > /*
> > * Use O_DSYNC by default instead of O_SYNC to forgo syncing
> > * of pure timestamp updates.
> > */
> > flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
>
> That code fragment comes from the LIO file backend. There is no requirement
> for a SCSI target core file backend to use O_DSYNC. SCST allows users to
> choose whether or not O_DSYNC should be used:
Yes, LIO file backend is the in-tree equivalent to NVMe's file backend. That's
why I copied it here.
>
> if (virt_dev->wt_flag && !virt_dev->nv_cache)
> open_flags |= O_DSYNC;
>
OK. Do your open_flags include O_DIRECT per default as well?
Byte,
Johannes
--
Johannes Thumshirn SUSE Labs Filesystems
jthumshirn@suse.de +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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next prev parent reply other threads:[~2019-02-25 15:38 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-21 18:22 [PATCH] nvmet: disable direct I/O when unavailable Johannes Thumshirn
2019-02-22 0:41 ` Chaitanya Kulkarni
2019-02-22 5:55 ` Johannes Thumshirn
2019-02-24 10:54 ` Max Gurtovoy
2019-02-25 9:37 ` Johannes Thumshirn
2019-02-25 14:49 ` Bart Van Assche
2019-02-25 15:38 ` Johannes Thumshirn [this message]
2019-02-25 16:10 ` Bart Van Assche
2019-02-25 21:18 ` Sagi Grimberg
2019-03-08 13:26 ` Christoph Hellwig
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