From: Kevin Wolf <kwolf@redhat.com>
To: Alberto Garcia <berto@igalia.com>
Cc: qemu-block@nongnu.org, pbonzini@redhat.com, mreitz@redhat.com,
eblake@redhat.com, stefanha@redhat.com, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH v2 08/13] block: Introduce BdrvChild.opaque
Date: Fri, 6 May 2016 15:19:05 +0200 [thread overview]
Message-ID: <20160506131905.GI5093@noname.redhat.com> (raw)
In-Reply-To: <w51shxv73dt.fsf@maestria.local.igalia.com>
Am 06.05.2016 um 14:54 hat Alberto Garcia geschrieben:
> On Fri 22 Apr 2016 07:42:37 PM CEST, Kevin Wolf wrote:
> > BlockBackends use it to get a back pointer from BdrvChild to
> > BlockBackend in any BdrvChildRole callbacks.
>
> Hmmm... can anyone else use this, other than BlockBackend? If not, why
> is it opaque?
If we ever want to call BdrvChild callbacks from somewhere else than the
top of the image, there will be others users of this. For example, I
could imagine .resize() or .change_media() to propagate through the
whole tree when the host_cdrom driver detected a media change.
At the moment we probably don't have another use for it, but it's the
usual style that callbacks get an opaque value, so I just followed the
pattern here. (And I don't want people to abuse this to get back from
BDS to BB outside of such callbacks.)
Kevin
next prev parent reply other threads:[~2016-05-06 13:20 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-22 17:42 [Qemu-devel] [PATCH v2 00/13] block: Move I/O throttling to BlockBackend Kevin Wolf
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 01/13] block: Make sure throttled BDSes always have a BB Kevin Wolf
2016-05-04 12:44 ` Alberto Garcia
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 02/13] block: Introduce BlockBackendPublic Kevin Wolf
2016-05-04 12:45 ` Alberto Garcia
2016-05-04 14:23 ` Eric Blake
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 03/13] block: throttle-groups: Use BlockBackend pointers internally Kevin Wolf
2016-05-04 12:51 ` Alberto Garcia
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 04/13] block: Convert throttle_group_get_name() to BlockBackend Kevin Wolf
2016-05-04 12:52 ` Alberto Garcia
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 05/13] block: Move throttling fields from BDS to BB Kevin Wolf
2016-05-04 13:36 ` Alberto Garcia
2016-05-09 12:43 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2016-05-11 12:45 ` Kevin Wolf
2016-05-10 12:36 ` [Qemu-devel] " Alberto Garcia
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 06/13] block: Move actual I/O throttling to BlockBackend Kevin Wolf
2016-05-04 13:05 ` Alberto Garcia
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 07/13] block: Move I/O throttling configuration functions " Kevin Wolf
2016-05-04 14:11 ` Alberto Garcia
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 08/13] block: Introduce BdrvChild.opaque Kevin Wolf
2016-05-06 12:54 ` Alberto Garcia
2016-05-06 13:19 ` Kevin Wolf [this message]
2016-05-06 15:13 ` Alberto Garcia
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 09/13] block: Drain throttling queue with BdrvChild callback Kevin Wolf
2016-05-06 15:13 ` Alberto Garcia
2016-05-09 13:17 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2016-05-09 15:42 ` Kevin Wolf
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 10/13] block: Decouple throttling from BlockDriverState Kevin Wolf
2016-05-10 12:38 ` Alberto Garcia
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 11/13] block: Remove bdrv_move_feature_fields() Kevin Wolf
2016-05-04 14:14 ` Alberto Garcia
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 12/13] Revert "block: Forbid I/O throttling on nodes with multiple parents for 2.6" Kevin Wolf
2016-05-09 12:31 ` Alberto Garcia
2016-04-22 17:42 ` [Qemu-devel] [PATCH v2 13/13] block: Don't check throttled reqs in bdrv_requests_pending() Kevin Wolf
2016-05-10 12:20 ` Alberto Garcia
2016-05-11 12:35 ` Kevin Wolf
2016-04-29 10:01 ` [Qemu-devel] [PATCH v2 00/13] block: Move I/O throttling to BlockBackend Kevin Wolf
2016-04-29 11:57 ` Alberto Garcia
2016-05-09 13:21 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
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