From bc284d49a00a1a716b380c2245aa0b897a259a5d Mon Sep 17 00:00:00 2001 From: Sergio Lopez Pascual Date: Thu, 11 Feb 2021 14:42:04 -0300 Subject: [PATCH 2/6] block: Honor blk_set_aio_context() context requirements RH-Author: Sergio Lopez Pascual Message-id: <20210211144208.58930-2-slp@redhat.com> Patchwork-id: 101049 O-Subject: [RHEL-AV-8.4.0 qemu-kvm PATCH 1/5] block: Honor blk_set_aio_context() context requirements Bugzilla: 1918966 1918968 RH-Acked-by: Max Reitz RH-Acked-by: Kevin Wolf RH-Acked-by: Eric Blake The documentation for bdrv_set_aio_context_ignore() states this: * The caller must own the AioContext lock for the old AioContext of bs, but it * must not own the AioContext lock for new_context (unless new_context is the * same as the current context of bs). As blk_set_aio_context() makes use of this function, this rule also applies to it. Fix all occurrences where this rule wasn't honored. Suggested-by: Kevin Wolf Signed-off-by: Sergio Lopez Message-Id: <20201214170519.223781-2-slp@redhat.com> Reviewed-by: Kevin Wolf Signed-off-by: Eric Blake (cherry picked from commit c7040ff64ec93ee925a81d3547db925fe7d1f1c0) Signed-off-by: Sergio Lopez Signed-off-by: Eduardo Lima (Etrunko) --- hw/block/dataplane/virtio-blk.c | 4 ++++ hw/block/dataplane/xen-block.c | 7 ++++++- hw/scsi/virtio-scsi.c | 6 ++++-- 3 files changed, 14 insertions(+), 3 deletions(-) diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index 37499c5564..e9050c8987 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -172,6 +172,7 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) VirtIOBlockDataPlane *s = vblk->dataplane; BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vblk))); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); + AioContext *old_context; unsigned i; unsigned nvqs = s->conf->num_queues; Error *local_err = NULL; @@ -214,7 +215,10 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) vblk->dataplane_started = true; trace_virtio_blk_data_plane_start(s); + old_context = blk_get_aio_context(s->conf->conf.blk); + aio_context_acquire(old_context); r = blk_set_aio_context(s->conf->conf.blk, s->ctx, &local_err); + aio_context_release(old_context); if (r < 0) { error_report_err(local_err); goto fail_guest_notifiers; diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c index 71c337c7b7..3675f8deaf 100644 --- a/hw/block/dataplane/xen-block.c +++ b/hw/block/dataplane/xen-block.c @@ -725,6 +725,7 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane, { ERRP_GUARD(); XenDevice *xendev = dataplane->xendev; + AioContext *old_context; unsigned int ring_size; unsigned int i; @@ -808,10 +809,14 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane, goto stop; } - aio_context_acquire(dataplane->ctx); + old_context = blk_get_aio_context(dataplane->blk); + aio_context_acquire(old_context); /* If other users keep the BlockBackend in the iothread, that's ok */ blk_set_aio_context(dataplane->blk, dataplane->ctx, NULL); + aio_context_release(old_context); + /* Only reason for failure is a NULL channel */ + aio_context_acquire(dataplane->ctx); xen_device_set_event_channel_context(xendev, dataplane->event_channel, dataplane->ctx, &error_abort); aio_context_release(dataplane->ctx); diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index 82c025146d..66bdda5473 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -821,6 +821,7 @@ static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev, VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev); VirtIOSCSI *s = VIRTIO_SCSI(vdev); SCSIDevice *sd = SCSI_DEVICE(dev); + AioContext *old_context; int ret; /* XXX: Remove this check once block backend is capable of handling @@ -836,9 +837,10 @@ static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev, if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) { return; } - virtio_scsi_acquire(s); + old_context = blk_get_aio_context(sd->conf.blk); + aio_context_acquire(old_context); ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp); - virtio_scsi_release(s); + aio_context_release(old_context); if (ret < 0) { return; } -- 2.27.0