qemu/blockdev-backup-don-t-check-aio_context-too-early.patch
2019-12-25 16:06:27 +08:00

54 lines
2.1 KiB
Diff

From 2429dc4eea91b381ff67a4d25ea9f6bbfe87c784 Mon Sep 17 00:00:00 2001
From: John Snow <jsnow@redhat.com>
Date: Thu, 23 May 2019 13:06:39 -0400
Subject: [PATCH] blockdev-backup: don't check aio_context too early
in blockdev_backup_prepare, we check to make sure that the target is
associated with a compatible aio context. However, do_blockdev_backup is
called later and has some logic to move the target to a compatible
aio_context. The transaction version will fail certain commands
needlessly early as a result.
Allow blockdev_backup_prepare to simply call do_blockdev_backup, which
will ultimately decide if the contexts are compatible or not.
Note: the transaction version has always disallowed this operation since
its initial commit bd8baecd (2014), whereas the version of
qmp_blockdev_backup at the time, from commit c29c1dd312f, tried to
enforce the aio_context switch instead. It's not clear, and I can't see
from the mailing list archives at the time, why the two functions take a
different approach. It wasn't until later in efd7556708b (2016) that the
standalone version tried to determine if it could set the context or
not.
Reported-by: aihua liang <aliang@redhat.com>
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1683498
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20190523170643.20794-2-jsnow@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
(cherry picked from commit d81e1efbea7d19c2f142d300df56538c73800590)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
blockdev.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index 4775a07d93..d358169995 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1871,10 +1871,6 @@ static void blockdev_backup_prepare(BlkActionState *common, Error **errp)
}
aio_context = bdrv_get_aio_context(bs);
- if (aio_context != bdrv_get_aio_context(target)) {
- error_setg(errp, "Backup between two IO threads is not implemented");
- return;
- }
aio_context_acquire(aio_context);
state->bs = bs;
--
2.19.1