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From: Paolo Bonzini <pbonzini@redhat.com>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Vijay Bellur <vbellur@redhat.com>,
	Amar Tumballi <amarts@redhat.com>,
	qemu-devel@nongnu.org, bharata@linux.vnet.ibm.com
Subject: Re: [Qemu-devel] [RFC PATCH 3/3] block: gluster as block backend
Date: Sun, 01 Jul 2012 16:49:29 +0200	[thread overview]
Message-ID: <4FF06379.9030808@redhat.com> (raw)
In-Reply-To: <CAJSP0QXRdEtzqeWYSv6gzgwkP1LT+TDDUEEMpbiB1P9EbLvFAQ@mail.gmail.com>

Il 18/06/2012 19:35, Stefan Hajnoczi ha scritto:
>> > +    /* Use O_DSYNC for write-through caching, no flags for write-back caching,
>> > +     * and O_DIRECT for no caching. */
>> > +    if ((bdrv_flags & BDRV_O_NOCACHE))
>> > +        s->open_flags |= O_DIRECT;
>> > +    if (!(bdrv_flags & BDRV_O_CACHE_WB))
>> > +        s->open_flags |= O_DSYNC;
> Paolo has changed this recently, you might need to use
> bs->enable_write_cache instead.

At the protocol (i.e. low-level backend) level you don't need to do
anything really, if you implement bdrv_flush_to_disk correctly.

Looking at BDRV_O_CACHE_WB will do no harm, it's just dead code.

Paolo

  parent reply	other threads:[~2012-07-01 14:49 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-11 14:18 [Qemu-devel] [RFC PATCH 0/3] GlusterFS support in QEMU Bharata B Rao
2012-06-11 14:19 ` [Qemu-devel] [RFC PATCH 1/3] qemu: Add a config option for GlusterFS as block backend Bharata B Rao
2012-06-11 14:20 ` [Qemu-devel] [RFC PATCH 2/3] block: GlusterFS helpers to interface with libglusterfs Bharata B Rao
2012-06-18 17:35   ` Stefan Hajnoczi
2012-06-19  9:31     ` Bharata B Rao
2012-07-02  9:52       ` Paolo Bonzini
2012-07-02 10:05         ` Bharata B Rao
2012-06-11 14:21 ` [Qemu-devel] [RFC PATCH 3/3] block: gluster as block backend Bharata B Rao
2012-06-18 17:35   ` Stefan Hajnoczi
2012-06-19  9:27     ` Avi Kivity
2012-06-19  9:30     ` Bharata B Rao
2012-06-19 11:05       ` Stefan Hajnoczi
2012-07-01 14:50         ` Paolo Bonzini
2012-07-01 14:49     ` Paolo Bonzini [this message]
2012-06-18 15:36 ` [Qemu-devel] [RFC PATCH 0/3] GlusterFS support in QEMU Stefan Hajnoczi
2012-06-19  9:10   ` Bharata B Rao
2012-07-06  5:35 ` Bharata B Rao

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