block: Add Error to blk_set_aio_context()

Add an Error parameter to blk_set_aio_context() and use
bdrv_child_try_set_aio_context() internally to check whether all
involved nodes can actually support the AioContext switch.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2019-05-02 11:10:59 +02:00
parent 45e92a9011
commit 97896a4887
7 changed files with 53 additions and 34 deletions

View File

@ -1865,30 +1865,36 @@ static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb)
return blk_get_aio_context(blk_acb->blk);
}
static void blk_do_set_aio_context(BlockBackend *blk, AioContext *new_context,
bool update_root_node)
static int blk_do_set_aio_context(BlockBackend *blk, AioContext *new_context,
bool update_root_node, Error **errp)
{
BlockDriverState *bs = blk_bs(blk);
ThrottleGroupMember *tgm = &blk->public.throttle_group_member;
int ret;
if (bs) {
if (update_root_node) {
ret = bdrv_child_try_set_aio_context(bs, new_context, blk->root,
errp);
if (ret < 0) {
return ret;
}
}
if (tgm->throttle_state) {
bdrv_drained_begin(bs);
throttle_group_detach_aio_context(tgm);
throttle_group_attach_aio_context(tgm, new_context);
bdrv_drained_end(bs);
}
if (update_root_node) {
GSList *ignore = g_slist_prepend(NULL, blk->root);
bdrv_set_aio_context_ignore(bs, new_context, &ignore);
g_slist_free(ignore);
}
}
return 0;
}
void blk_set_aio_context(BlockBackend *blk, AioContext *new_context)
int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
Error **errp)
{
blk_do_set_aio_context(blk, new_context, true);
return blk_do_set_aio_context(blk, new_context, true, errp);
}
static bool blk_root_can_set_aio_ctx(BdrvChild *child, AioContext *ctx,
@ -1915,7 +1921,7 @@ static void blk_root_set_aio_ctx(BdrvChild *child, AioContext *ctx,
GSList **ignore)
{
BlockBackend *blk = child->opaque;
blk_do_set_aio_context(blk, ctx, false);
blk_do_set_aio_context(blk, ctx, false, &error_abort);
}
void blk_add_aio_context_notifier(BlockBackend *blk,

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@ -173,6 +173,7 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev)
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
unsigned i;
unsigned nvqs = s->conf->num_queues;
Error *local_err = NULL;
int r;
if (vblk->dataplane_started || s->starting) {
@ -212,7 +213,11 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev)
vblk->dataplane_started = true;
trace_virtio_blk_data_plane_start(s);
blk_set_aio_context(s->conf->conf.blk, s->ctx);
r = blk_set_aio_context(s->conf->conf.blk, s->ctx, &local_err);
if (r < 0) {
error_report_err(local_err);
goto fail_guest_notifiers;
}
/* Kick right away to begin processing requests already in vring */
for (i = 0; i < nvqs; i++) {
@ -281,8 +286,9 @@ void virtio_blk_data_plane_stop(VirtIODevice *vdev)
aio_context_acquire(s->ctx);
aio_wait_bh_oneshot(s->ctx, virtio_blk_data_plane_stop_bh, s);
/* Drain and switch bs back to the QEMU main loop */
blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context());
/* Drain and try to switch bs back to the QEMU main loop. If other users
* keep the BlockBackend in the iothread, that's ok */
blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context(), NULL);
aio_context_release(s->ctx);

View File

@ -682,7 +682,8 @@ void xen_block_dataplane_stop(XenBlockDataPlane *dataplane)
}
aio_context_acquire(dataplane->ctx);
blk_set_aio_context(dataplane->blk, qemu_get_aio_context());
/* Xen doesn't have multiple users for nodes, so this can't fail */
blk_set_aio_context(dataplane->blk, qemu_get_aio_context(), &error_abort);
aio_context_release(dataplane->ctx);
xendev = dataplane->xendev;
@ -811,7 +812,8 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
}
aio_context_acquire(dataplane->ctx);
blk_set_aio_context(dataplane->blk, dataplane->ctx);
/* If other users keep the BlockBackend in the iothread, that's ok */
blk_set_aio_context(dataplane->blk, dataplane->ctx, NULL);
aio_context_release(dataplane->ctx);
return;

View File

@ -795,6 +795,7 @@ 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);
int ret;
if (s->ctx && !s->dataplane_fenced) {
AioContext *ctx;
@ -808,9 +809,11 @@ static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
return;
}
virtio_scsi_acquire(s);
blk_set_aio_context(sd->conf.blk, s->ctx);
ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
virtio_scsi_release(s);
if (ret < 0) {
return;
}
}
if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
@ -839,7 +842,8 @@ static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
if (s->ctx) {
virtio_scsi_acquire(s);
blk_set_aio_context(sd->conf.blk, qemu_get_aio_context());
/* If other users keep the BlockBackend in the iothread, that's ok */
blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL);
virtio_scsi_release(s);
}

View File

@ -208,7 +208,8 @@ void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason);
void blk_op_block_all(BlockBackend *blk, Error *reason);
void blk_op_unblock_all(BlockBackend *blk, Error *reason);
AioContext *blk_get_aio_context(BlockBackend *blk);
void blk_set_aio_context(BlockBackend *blk, AioContext *new_context);
int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
Error **errp);
void blk_add_aio_context_notifier(BlockBackend *blk,
void (*attached_aio_context)(AioContext *new_context, void *opaque),
void (*detach_aio_context)(void *opaque), void *opaque);

View File

@ -678,7 +678,7 @@ static void test_iothread_common(enum drain_type drain_type, int drain_thread)
s = bs->opaque;
blk_insert_bs(blk, bs, &error_abort);
blk_set_aio_context(blk, ctx_a);
blk_set_aio_context(blk, ctx_a, &error_abort);
aio_context_acquire(ctx_a);
s->bh_indirection_ctx = ctx_b;
@ -742,7 +742,7 @@ static void test_iothread_common(enum drain_type drain_type, int drain_thread)
}
aio_context_acquire(ctx_a);
blk_set_aio_context(blk, qemu_get_aio_context());
blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
aio_context_release(ctx_a);
bdrv_unref(bs);
@ -903,7 +903,7 @@ static void test_blockjob_common_drain_node(enum drain_type drain_type,
if (use_iothread) {
iothread = iothread_new();
ctx = iothread_get_aio_context(iothread);
blk_set_aio_context(blk_src, ctx);
blk_set_aio_context(blk_src, ctx, &error_abort);
} else {
ctx = qemu_get_aio_context();
}
@ -1001,7 +1001,7 @@ static void test_blockjob_common_drain_node(enum drain_type drain_type,
g_assert_cmpint(ret, ==, (result == TEST_JOB_SUCCESS ? 0 : -EIO));
if (use_iothread) {
blk_set_aio_context(blk_src, qemu_get_aio_context());
blk_set_aio_context(blk_src, qemu_get_aio_context(), &error_abort);
}
aio_context_release(ctx);

View File

@ -342,14 +342,14 @@ static void test_sync_op(const void *opaque)
blk_insert_bs(blk, bs, &error_abort);
c = QLIST_FIRST(&bs->parents);
blk_set_aio_context(blk, ctx);
blk_set_aio_context(blk, ctx, &error_abort);
aio_context_acquire(ctx);
t->fn(c);
if (t->blkfn) {
t->blkfn(blk);
}
aio_context_release(ctx);
blk_set_aio_context(blk, qemu_get_aio_context());
blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
bdrv_unref(bs);
blk_unref(blk);
@ -428,7 +428,7 @@ static void test_attach_blockjob(void)
aio_poll(qemu_get_aio_context(), false);
}
blk_set_aio_context(blk, ctx);
blk_set_aio_context(blk, ctx, &error_abort);
tjob->n = 0;
while (tjob->n == 0) {
@ -436,7 +436,7 @@ static void test_attach_blockjob(void)
}
aio_context_acquire(ctx);
blk_set_aio_context(blk, qemu_get_aio_context());
blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
aio_context_release(ctx);
tjob->n = 0;
@ -444,7 +444,7 @@ static void test_attach_blockjob(void)
aio_poll(qemu_get_aio_context(), false);
}
blk_set_aio_context(blk, ctx);
blk_set_aio_context(blk, ctx, &error_abort);
tjob->n = 0;
while (tjob->n == 0) {
@ -453,7 +453,7 @@ static void test_attach_blockjob(void)
aio_context_acquire(ctx);
job_complete_sync(&tjob->common.job, &error_abort);
blk_set_aio_context(blk, qemu_get_aio_context());
blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
aio_context_release(ctx);
bdrv_unref(bs);
@ -497,7 +497,7 @@ static void test_propagate_basic(void)
bs_verify = bdrv_open(NULL, NULL, options, BDRV_O_RDWR, &error_abort);
/* Switch the AioContext */
blk_set_aio_context(blk, ctx);
blk_set_aio_context(blk, ctx, &error_abort);
g_assert(blk_get_aio_context(blk) == ctx);
g_assert(bdrv_get_aio_context(bs_a) == ctx);
g_assert(bdrv_get_aio_context(bs_verify) == ctx);
@ -505,7 +505,7 @@ static void test_propagate_basic(void)
/* Switch the AioContext back */
ctx = qemu_get_aio_context();
blk_set_aio_context(blk, ctx);
blk_set_aio_context(blk, ctx, &error_abort);
g_assert(blk_get_aio_context(blk) == ctx);
g_assert(bdrv_get_aio_context(bs_a) == ctx);
g_assert(bdrv_get_aio_context(bs_verify) == ctx);
@ -565,7 +565,7 @@ static void test_propagate_diamond(void)
blk_insert_bs(blk, bs_verify, &error_abort);
/* Switch the AioContext */
blk_set_aio_context(blk, ctx);
blk_set_aio_context(blk, ctx, &error_abort);
g_assert(blk_get_aio_context(blk) == ctx);
g_assert(bdrv_get_aio_context(bs_verify) == ctx);
g_assert(bdrv_get_aio_context(bs_a) == ctx);
@ -574,7 +574,7 @@ static void test_propagate_diamond(void)
/* Switch the AioContext back */
ctx = qemu_get_aio_context();
blk_set_aio_context(blk, ctx);
blk_set_aio_context(blk, ctx, &error_abort);
g_assert(blk_get_aio_context(blk) == ctx);
g_assert(bdrv_get_aio_context(bs_verify) == ctx);
g_assert(bdrv_get_aio_context(bs_a) == ctx);
@ -654,7 +654,7 @@ static void test_propagate_mirror(void)
job_cancel_sync_all();
aio_context_acquire(ctx);
blk_set_aio_context(blk, main_ctx);
blk_set_aio_context(blk, main_ctx, &error_abort);
bdrv_try_set_aio_context(target, main_ctx, &error_abort);
aio_context_release(ctx);