pve-qemu-qoup/debian/patches/pve/0046-block-io-accept-NULL-qiov-in-bdrv_pad_request.patch
Fabian Ebner 27199bd753 backup: add patch to initialize bcs bitmap early enough for PBS
This is necessary for multi-disk backups where not all jobs are
immediately started after they are created. QEMU commit
06e0a9c16405c0a4c1eca33cf286cc04c42066a2 did already part of the work,
ensuring that new writes after job creation don't pass through to the
backup, but not yet for the MIRROR_SYNC_MODE_BITMAP case which is used
for PBS.

Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
2022-03-03 11:37:17 +01:00

34 lines
1.1 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Stefan Reiter <s.reiter@proxmox.com>
Date: Tue, 2 Mar 2021 16:11:54 +0100
Subject: [PATCH] block/io: accept NULL qiov in bdrv_pad_request
Some operations, e.g. block-stream, perform reads while discarding the
results (only copy-on-read matters). In this case they will pass NULL as
the target QEMUIOVector, which will however trip bdrv_pad_request, since
it wants to extend its passed vector.
Simply check for NULL and do nothing, there's no reason to pad the
target if it will be discarded anyway.
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
---
block/io.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/block/io.c b/block/io.c
index 4e4cb556c5..04061f1e68 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1765,6 +1765,10 @@ static int bdrv_pad_request(BlockDriverState *bs,
{
int ret;
+ if (!qiov) {
+ return 0;
+ }
+
bdrv_check_qiov_request(*offset, *bytes, *qiov, *qiov_offset, &error_abort);
if (!bdrv_init_padding(bs, *offset, *bytes, pad)) {