From: Paolo Bonzini <pbonzini@redhat.com>
To: jcody@redhat.com
Cc: kwolf@redhat.com, supriyak@linux.vnet.ibm.com, eblake@redhat.com,
qemu-devel@nongnu.org, stefanha@gmail.com
Subject: Re: [Qemu-devel] [PATCH v2 06/16] block: do not parse BDRV_O_CACHE_WB in raw block drivers
Date: Thu, 13 Sep 2012 20:56:51 +0200 [thread overview]
Message-ID: <50522C73.5030100@redhat.com> (raw)
In-Reply-To: <50521531.6010308@redhat.com>
Il 13/09/2012 19:17, Jeff Cody ha scritto:
>> >
>> > Why does this matter? If raw-posix was opened directly (i.e. without
>> > the bs->file indirection) this would cause a writethrough file to be
>> > incorrectly opened as writeback.
>> >
>> > Paolo
>> >
> The problem this patch was trying to work around is that
> bdrv_open_common() forces BDRV_O_CACHE_WB (commit e1e9b0ac), but that
> setting is not preserved in bs->open_flags, so it is lost on a reopen.
Perhaps we _should_ preserve that in bs->open_flags, while still using
the initial value of BDRV_O_CACHE_WB to initialize bs->enable_write_cache.
> Is there a scenario currently that has raw-posix opened directly as a
> writethrough file, or were you more concerned with future use?
Not for raw-posix, but IIRC some other protocol is opened directly
without a format on top. rbd perhaps? I'm concerned of having to work
around what seems like a bug elsewhere, in multiple protocols.
Paolo
next prev parent reply other threads:[~2012-09-13 18:56 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-13 15:49 [Qemu-devel] [PATCH v2 00/16] block: bdrv_reopen() patches Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 01/16] block: correctly set the keep_read_only flag Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 02/16] block: make bdrv_set_enable_write_cache() modify open_flags Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 03/16] block: Framework for reopening files safely Jeff Cody
2012-09-13 16:20 ` Paolo Bonzini
2012-09-13 20:35 ` Paolo Bonzini
2012-09-13 20:51 ` Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 04/16] block: move aio initialization into a helper function Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 05/16] block: move open flag parsing in raw block drivers to helper functions Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 06/16] block: do not parse BDRV_O_CACHE_WB in raw block drivers Jeff Cody
2012-09-13 16:12 ` Paolo Bonzini
2012-09-13 17:17 ` Jeff Cody
2012-09-13 18:56 ` Paolo Bonzini [this message]
2012-09-13 19:04 ` Jeff Cody
2012-09-13 19:44 ` Paolo Bonzini
2012-09-13 20:29 ` Paolo Bonzini
2012-09-13 21:45 ` Jeff Cody
2012-09-14 6:51 ` Paolo Bonzini
2012-09-14 7:54 ` Kevin Wolf
2012-09-14 7:27 ` Kevin Wolf
2012-09-14 7:50 ` Paolo Bonzini
2012-09-14 7:55 ` Kevin Wolf
2012-09-14 7:55 ` Paolo Bonzini
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 07/16] block: move allocating aligned_buf into a helper function in raw_posix.c Jeff Cody
2012-09-13 17:29 ` Eric Blake
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 08/16] block: raw-posix image file reopen Jeff Cody
2012-09-13 16:02 ` Paolo Bonzini
2012-09-13 16:57 ` Jeff Cody
2012-09-14 7:32 ` Kevin Wolf
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 09/16] block: raw " Jeff Cody
2012-09-13 16:05 ` Paolo Bonzini
2012-09-13 17:02 ` Jeff Cody
2012-09-13 18:53 ` Paolo Bonzini
2012-09-13 19:17 ` Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 10/16] block: qed " Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 11/16] block: qcow2 " Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 12/16] block: qcow " Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 13/16] block: vmdk " Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 14/16] block: raw-win32 driver reopen support Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 15/16] block: convert bdrv_commit() to use bdrv_reopen() Jeff Cody
2012-09-13 15:49 ` [Qemu-devel] [PATCH v2 16/16] block: remove keep_read_only flag from BlockDriverState struct Jeff Cody
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