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Re: [Qemu-block] [PATCH 2/3] virtio-blk: Remove op blocker for dataplane
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-block] [PATCH 2/3] virtio-blk: Remove op blocker for dataplane |
Date: |
Wed, 18 May 2016 11:26:10 +0300 |
On Wed, May 18, 2016 at 04:24:09PM +0800, Fam Zheng wrote:
> Block layer is prepared to unspecialize dataplane, an evidence is this
> almost complete list of unblocked operations. It has all types except
> two (actually three if DATAPLANE itself counts but blockdev.c makes sure
> attaching twice is not possible): MIRROR_TARGET and BACKUP_TARGET.
>
> blockdev-mirror refuses to start if target is attached, so the first is
> not a problem.
>
> By removing BACKUP_TARGET, blockdev-backup will become permissive to
> write to a virtio-blk dataplane disk, but that is not worse than
> non-dataplane given the latter is already possible. In either case,
> blockdev.c always checks the target and source are on the same
> AioContext, or bring them together if possible.
>
> Signed-off-by: Fam Zheng <address@hidden>
Acked-by: Michael S. Tsirkin <address@hidden>
> ---
> hw/block/dataplane/virtio-blk.c | 63
> -----------------------------------------
> 1 file changed, 63 deletions(-)
>
> diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
> index 3cb97c9..2073f9a 100644
> --- a/hw/block/dataplane/virtio-blk.c
> +++ b/hw/block/dataplane/virtio-blk.c
> @@ -37,8 +37,6 @@ struct VirtIOBlockDataPlane {
> EventNotifier *guest_notifier; /* irq */
> QEMUBH *bh; /* bh for guest notification */
>
> - Notifier insert_notifier, remove_notifier;
> -
> /* Note that these EventNotifiers are assigned by value. This is
> * fine as long as you do not call event_notifier_cleanup on them
> * (because you don't own the file descriptor or handle; you just
> @@ -46,9 +44,6 @@ struct VirtIOBlockDataPlane {
> */
> IOThread *iothread;
> AioContext *ctx;
> -
> - /* Operation blocker on BDS */
> - Error *blocker;
> };
>
> /* Raise an interrupt to signal guest, if necessary */
> @@ -68,54 +63,6 @@ static void notify_guest_bh(void *opaque)
> event_notifier_set(s->guest_notifier);
> }
>
> -static void data_plane_set_up_op_blockers(VirtIOBlockDataPlane *s)
> -{
> - assert(!s->blocker);
> - error_setg(&s->blocker, "block device is in use by data plane");
> - blk_op_block_all(s->conf->conf.blk, s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_RESIZE, s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_DRIVE_DEL, s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_BACKUP_SOURCE,
> s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_CHANGE, s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_COMMIT_SOURCE,
> s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_COMMIT_TARGET,
> s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_EJECT, s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
> - s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
> - s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
> - s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_MIRROR_SOURCE,
> s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_STREAM, s->blocker);
> - blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_REPLACE, s->blocker);
> -}
> -
> -static void data_plane_remove_op_blockers(VirtIOBlockDataPlane *s)
> -{
> - if (s->blocker) {
> - blk_op_unblock_all(s->conf->conf.blk, s->blocker);
> - error_free(s->blocker);
> - s->blocker = NULL;
> - }
> -}
> -
> -static void data_plane_blk_insert_notifier(Notifier *n, void *data)
> -{
> - VirtIOBlockDataPlane *s = container_of(n, VirtIOBlockDataPlane,
> - insert_notifier);
> - assert(s->conf->conf.blk == data);
> - data_plane_set_up_op_blockers(s);
> -}
> -
> -static void data_plane_blk_remove_notifier(Notifier *n, void *data)
> -{
> - VirtIOBlockDataPlane *s = container_of(n, VirtIOBlockDataPlane,
> - remove_notifier);
> - assert(s->conf->conf.blk == data);
> - data_plane_remove_op_blockers(s);
> -}
> -
> /* Context: QEMU global mutex held */
> void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
> VirtIOBlockDataPlane **dataplane,
> @@ -158,13 +105,6 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev,
> VirtIOBlkConf *conf,
> s->ctx = iothread_get_aio_context(s->iothread);
> s->bh = aio_bh_new(s->ctx, notify_guest_bh, s);
>
> - s->insert_notifier.notify = data_plane_blk_insert_notifier;
> - s->remove_notifier.notify = data_plane_blk_remove_notifier;
> - blk_add_insert_bs_notifier(conf->conf.blk, &s->insert_notifier);
> - blk_add_remove_bs_notifier(conf->conf.blk, &s->remove_notifier);
> -
> - data_plane_set_up_op_blockers(s);
> -
> *dataplane = s;
> }
>
> @@ -176,9 +116,6 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane
> *s)
> }
>
> virtio_blk_data_plane_stop(s);
> - data_plane_remove_op_blockers(s);
> - notifier_remove(&s->insert_notifier);
> - notifier_remove(&s->remove_notifier);
> qemu_bh_delete(s->bh);
> object_unref(OBJECT(s->iothread));
> g_free(s);
> --
> 2.8.2
- [Qemu-block] [PATCH 0/3] Drop virtio-{blk,scsi} op blockers, Fam Zheng, 2016/05/18
- [Qemu-block] [PATCH 1/3] blockdev-backup: Don't move target AioContext if it's attached, Fam Zheng, 2016/05/18
- [Qemu-block] [PATCH 2/3] virtio-blk: Remove op blocker for dataplane, Fam Zheng, 2016/05/18
- Re: [Qemu-block] [PATCH 2/3] virtio-blk: Remove op blocker for dataplane,
Michael S. Tsirkin <=
- [Qemu-block] [PATCH 3/3] virtio-scsi: Remove op blocker for dataplane, Fam Zheng, 2016/05/18
- Re: [Qemu-block] [PATCH 0/3] Drop virtio-{blk,scsi} op blockers, Michael S. Tsirkin, 2016/05/18
- Re: [Qemu-block] [PATCH 0/3] Drop virtio-{blk,scsi} op blockers, Stefan Hajnoczi, 2016/05/19
- Re: [Qemu-block] [PATCH 0/3] Drop virtio-{blk,scsi} op blockers, Stefan Hajnoczi, 2016/05/19