pve-qemu-qoup/debian/patches/pve/0047-block-io-accept-NULL-qiov-in-bdrv_pad_request.patch

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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
update submodule and patches to QEMU 8.0.0 Many changes were necessary this time around: * QAPI was changed to avoid redundant has_* variables, see commit 44ea9d9be3 ("qapi: Start to elide redundant has_FOO in generated C") for details. This affected many QMP commands added by Proxmox too. * Pending querying for migration got split into two functions, one to estimate, one for exact value, see commit c8df4a7aef ("migration: Split save_live_pending() into state_pending_*") for details. Relevant for savevm-async and PBS dirty bitmap. * Some block (driver) functions got converted to coroutines, so the Proxmox block drivers needed to be adapted. * Alloc track auto-detaching during PBS live restore got broken by AioContext-related changes resulting in a deadlock. The current, hacky method was replaced by a simpler one. Stefan apparently ran into a problem with that when he wrote the driver, but there were improvements in the stream job code since then and I didn't manage to reproduce the issue. It's a separate patch "alloc-track: fix deadlock during drop" for now, you can find the details there. * Async snapshot-related changes: - The pending querying got adapted to the above-mentioned split and a patch is added to optimize it/make it more similar to what upstream code does. - Added initialization of the compression counters (for future-proofing). - It's necessary the hold the BQL (big QEMU lock = iothread mutex) during the setup phase, because block layer functions are used there and not doing so leads to racy, hard-to-debug crashes or hangs. It's necessary to change some upstream code too for this, a version of the patch "migration: for snapshots, hold the BQL during setup callbacks" is intended to be upstreamed. - Need to take the bdrv graph read lock before flushing. * hmp_info_balloon was moved to a different file. * Needed to include a new headers from time to time to still get the correct functions. Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-05-15 16:39:53 +03:00
index 2e267a85ab..449a44bf20 100644
--- a/block/io.c
+++ b/block/io.c
update submodule and patches to QEMU 8.0.0 Many changes were necessary this time around: * QAPI was changed to avoid redundant has_* variables, see commit 44ea9d9be3 ("qapi: Start to elide redundant has_FOO in generated C") for details. This affected many QMP commands added by Proxmox too. * Pending querying for migration got split into two functions, one to estimate, one for exact value, see commit c8df4a7aef ("migration: Split save_live_pending() into state_pending_*") for details. Relevant for savevm-async and PBS dirty bitmap. * Some block (driver) functions got converted to coroutines, so the Proxmox block drivers needed to be adapted. * Alloc track auto-detaching during PBS live restore got broken by AioContext-related changes resulting in a deadlock. The current, hacky method was replaced by a simpler one. Stefan apparently ran into a problem with that when he wrote the driver, but there were improvements in the stream job code since then and I didn't manage to reproduce the issue. It's a separate patch "alloc-track: fix deadlock during drop" for now, you can find the details there. * Async snapshot-related changes: - The pending querying got adapted to the above-mentioned split and a patch is added to optimize it/make it more similar to what upstream code does. - Added initialization of the compression counters (for future-proofing). - It's necessary the hold the BQL (big QEMU lock = iothread mutex) during the setup phase, because block layer functions are used there and not doing so leads to racy, hard-to-debug crashes or hangs. It's necessary to change some upstream code too for this, a version of the patch "migration: for snapshots, hold the BQL during setup callbacks" is intended to be upstreamed. - Need to take the bdrv graph read lock before flushing. * hmp_info_balloon was moved to a different file. * Needed to include a new headers from time to time to still get the correct functions. Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-05-15 16:39:53 +03:00
@@ -1576,6 +1576,10 @@ 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)) {