[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PULL 2/6] virtio-blk: add missing AioContext lock
From: |
Stefan Hajnoczi |
Subject: |
[PULL 2/6] virtio-blk: add missing AioContext lock |
Date: |
Thu, 9 Feb 2023 10:25:16 -0500 |
From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
virtio_blk_update_config() calls blk_get_geometry and blk_getlength,
and both functions eventually end up calling bdrv_poll_co when not
running in a coroutine:
- blk_getlength is a co_wrapper_mixed function
- blk_get_geometry calls bdrv_get_geometry -> bdrv_nb_sectors, a
co_wrapper_mixed function too
Since we are not running in a coroutine, we need to take s->blk
AioContext lock, otherwise bdrv_poll_co will inevitably call
AIO_WAIT_WHILE and therefore try to un unlock() an AioContext lock
that was never acquired.
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=2167838
Steps to reproduce the issue: simply boot a VM with
-object '{"qom-type":"iothread","id":"iothread1"}' \
-blockdev
'{"driver":"file","filename":"$QCOW2","aio":"native","node-name":"libvirt-1-storage","cache":{"direct":true,"no-flush":false},"auto-read-only":true,"discard":"unmap"}'
\
-blockdev
'{"node-name":"libvirt-1-format","read-only":false,"cache":{"direct":true,"no-flush":false},"driver":"qcow2","file":"libvirt-1-storage"}'
\
-device
virtio-blk-pci,iothread=iothread1,drive=libvirt-1-format,id=virtio-disk0,bootindex=1,write-cache=on
and observe that it will fail not manage to boot with "qemu_mutex_unlock_impl:
Operation not permitted"
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Lukáš Doktor <ldoktor@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230208111148.1040083-1-eesposit@redhat.com>
---
hw/block/virtio-blk.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 1762517878..cefca93b31 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -894,6 +894,10 @@ static void virtio_blk_update_config(VirtIODevice *vdev,
uint8_t *config)
uint64_t capacity;
int64_t length;
int blk_size = conf->logical_block_size;
+ AioContext *ctx;
+
+ ctx = blk_get_aio_context(s->blk);
+ aio_context_acquire(ctx);
blk_get_geometry(s->blk, &capacity);
memset(&blkcfg, 0, sizeof(blkcfg));
@@ -917,6 +921,7 @@ static void virtio_blk_update_config(VirtIODevice *vdev,
uint8_t *config)
* per track (cylinder).
*/
length = blk_getlength(s->blk);
+ aio_context_release(ctx);
if (length > 0 && length / conf->heads / conf->secs % blk_size) {
blkcfg.geometry.sectors = conf->secs & ~s->sector_mask;
} else {
--
2.39.1
- [PULL 0/6] Block patches, Stefan Hajnoczi, 2023/02/09
- [PULL 1/6] vhost-user-fs: Back up vqs before cleaning up vhost_dev, Stefan Hajnoczi, 2023/02/09
- [PULL 2/6] virtio-blk: add missing AioContext lock,
Stefan Hajnoczi <=
- [PULL 3/6] block: fix detect-zeroes= with BDRV_REQ_REGISTERED_BUF, Stefan Hajnoczi, 2023/02/09
- [PULL 4/6] qemu-io: use BdrvRequestFlags instead of int, Stefan Hajnoczi, 2023/02/09
- [PULL 5/6] qemu-io: add -r option to register I/O buffer, Stefan Hajnoczi, 2023/02/09
- [PULL 6/6] iotests/detect-zeroes-registered-buf: add new test, Stefan Hajnoczi, 2023/02/09
- Re: [PULL 0/6] Block patches, Peter Maydell, 2023/02/10