pve-qemu-qoup/debian/patches/extra/0010-migration-block-dirty-bitmap-fix-loading-bitmap-when.patch
Fiona Ebner 5919ec1446 add patch fixing resume for snapshot and hibernate with drive with iothread and a dirty bitmap
Not difficult to run into, just have a drive with iothread, take a PBS
backup and then take a snapshot or hibernate. Resuming will fail with
> qemu: qemu_mutex_unlock_impl: Operation not permitted
because of not acquiring the correct AioContext first.

Migration is not affected, because it runs in coroutine context.

Reported in the community forum:
https://forum.proxmox.com/threads/129899/

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-07-28 12:00:50 +02:00

49 lines
2.0 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Fiona Ebner <f.ebner@proxmox.com>
Date: Fri, 28 Jul 2023 10:47:48 +0200
Subject: [PATCH] migration/block-dirty-bitmap: fix loading bitmap when there
is an iothread
The bdrv_create_dirty_bitmap() function (which is also called by
bdrv_dirty_bitmap_create_successor()) uses bdrv_getlength(bs). This is
a wrapper around a coroutine, and thus uses bdrv_poll_co(). Polling
tries to release the AioContext which will trigger an assert() if it
hasn't been acquired before.
The issue does not happen for migration, because there we are in a
coroutine already, so the wrapper will just call bdrv_co_getlength()
directly without polling.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
migration/block-dirty-bitmap.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index fe73aa94b1..7eaf498439 100644
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -805,8 +805,11 @@ static int dirty_bitmap_load_start(QEMUFile *f, DBMLoadState *s)
"destination", bdrv_dirty_bitmap_name(s->bitmap));
return -EINVAL;
} else {
+ AioContext *ctx = bdrv_get_aio_context(s->bs);
+ aio_context_acquire(ctx);
s->bitmap = bdrv_create_dirty_bitmap(s->bs, granularity,
s->bitmap_name, &local_err);
+ aio_context_release(ctx);
if (!s->bitmap) {
error_report_err(local_err);
return -EINVAL;
@@ -833,7 +836,10 @@ static int dirty_bitmap_load_start(QEMUFile *f, DBMLoadState *s)
bdrv_disable_dirty_bitmap(s->bitmap);
if (flags & DIRTY_BITMAP_MIG_START_FLAG_ENABLED) {
+ AioContext *ctx = bdrv_get_aio_context(s->bs);
+ aio_context_acquire(ctx);
bdrv_dirty_bitmap_create_successor(s->bitmap, &local_err);
+ aio_context_release(ctx);
if (local_err) {
error_report_err(local_err);
return -EINVAL;