[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PULL 24/24] vhost-user-blk: Implement reconnection during realize
From: |
Kevin Wolf |
Subject: |
[PULL 24/24] vhost-user-blk: Implement reconnection during realize |
Date: |
Wed, 30 Jun 2021 18:02:06 +0200 |
Commit dabefdd6 removed code that was supposed to try reconnecting
during .realize(), but actually just crashed and had several design
problems.
This adds the feature back without the crash in simple cases while also
fixing some design problems: Reconnection is now only tried if there was
a problem with the connection and not an error related to the content
(which would fail again the same way in the next attempt). Reconnection
is limited to three attempts (four with the initial attempt) so that we
won't end up in an infinite loop if a problem is permanent. If the
backend restarts three times in the very short time window of device
initialisation, we have bigger problems and erroring out is the right
course of action.
In the case that a connection error occurs and we reconnect, the error
message is printed using error_report_err(), but otherwise ignored.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210609154658.350308-8-kwolf@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
hw/block/vhost-user-blk.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index e49d2e4c83..ba13cb87e5 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -31,6 +31,8 @@
#include "sysemu/sysemu.h"
#include "sysemu/runstate.h"
+#define REALIZE_CONNECTION_RETRIES 3
+
static const int user_feature_bits[] = {
VIRTIO_BLK_F_SIZE_MAX,
VIRTIO_BLK_F_SEG_MAX,
@@ -455,8 +457,10 @@ static int vhost_user_blk_realize_connect(VHostUserBlk *s,
Error **errp)
static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
{
+ ERRP_GUARD();
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserBlk *s = VHOST_USER_BLK(vdev);
+ int retries;
int i, ret;
if (!s->chardev.chr) {
@@ -498,7 +502,17 @@ static void vhost_user_blk_device_realize(DeviceState
*dev, Error **errp)
s->inflight = g_new0(struct vhost_inflight, 1);
s->vhost_vqs = g_new0(struct vhost_virtqueue, s->num_queues);
- ret = vhost_user_blk_realize_connect(s, errp);
+ retries = REALIZE_CONNECTION_RETRIES;
+ assert(!*errp);
+ do {
+ if (*errp) {
+ error_prepend(errp, "Reconnecting after error: ");
+ error_report_err(*errp);
+ *errp = NULL;
+ }
+ ret = vhost_user_blk_realize_connect(s, errp);
+ } while (ret == -EPROTO && retries--);
+
if (ret < 0) {
goto virtio_err;
}
--
2.31.1
- [PULL 13/24] block: Allow changing bs->file on reopen, (continued)
- [PULL 13/24] block: Allow changing bs->file on reopen, Kevin Wolf, 2021/06/30
- [PULL 04/24] block: rename bdrv_replace_child to bdrv_replace_child_tran, Kevin Wolf, 2021/06/30
- [PULL 17/24] block/ssh: add support for sha256 host key fingerprints, Kevin Wolf, 2021/06/30
- [PULL 15/24] introduce QEMU_AUTO_VFREE, Kevin Wolf, 2021/06/30
- [PULL 18/24] vhost: Add Error parameter to vhost_dev_init(), Kevin Wolf, 2021/06/30
- [PULL 16/24] block/commit: use QEMU_AUTO_VFREE, Kevin Wolf, 2021/06/30
- [PULL 22/24] vhost: Distinguish errors in vhost_dev_get_config(), Kevin Wolf, 2021/06/30
- [PULL 23/24] vhost-user-blk: Factor out vhost_user_blk_realize_connect(), Kevin Wolf, 2021/06/30
- [PULL 14/24] iotests: Test replacing files with x-blockdev-reopen, Kevin Wolf, 2021/06/30
- [PULL 20/24] vhost: Return 0/-errno in vhost_dev_init(), Kevin Wolf, 2021/06/30
- [PULL 24/24] vhost-user-blk: Implement reconnection during realize,
Kevin Wolf <=
- [PULL 21/24] vhost-user-blk: Add Error parameter to vhost_user_blk_start(), Kevin Wolf, 2021/06/30
- [PULL 05/24] block: comment graph-modifying function not updating permissions, Kevin Wolf, 2021/06/30
- [PULL 19/24] vhost: Distinguish errors in vhost_backend_init(), Kevin Wolf, 2021/06/30