pve-qemu-qoup/debian/patches/pve/0046-block-io-accept-NULL-qiov-in-bdrv_pad_request.patch
Stefan Reiter 8dca018b68 udpate and rebase to QEMU v6.0.0
Mostly minor changes, bigger ones summarized:
* QEMU's internal backup code now uses a new async system, which allows
  parallel requests - the default max_workers settings is 64, I chose
  less, since 64 put enough stress on QEMU that the guest became
  practically unusable during the backup, and 16 still shows quite a
  nice measureable performance improvement. Little code changes for us
  though.
* 'malformed' QAPI parameters/functions are now a build error (i.e.
  using '_' vs '-'), I chose to just whitelist our calls in the name of
  backwards compatibility.
* monitor OOB race fix now uses the upstream variant, cherry-picked from
  origin/master since it's not in 6.0 by default
* last patch fixes a bug with snapshot rollback related to the new yank
  system

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
2021-05-28 11:29:44 +02:00

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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.
---
block/io.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/block/io.c b/block/io.c
index ca2dca3007..a9e70a4f91 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1731,6 +1731,10 @@ 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)) {