pve-qemu-qoup/debian/patches/extra/0006-block-io-Update-BSC-only-if-want_zero-is-true.patch
Fabian Ebner 4567474e95 update submodule and patches to 6.2.0
Notable changes:
* bdrv_co_p{discard,readv,writev,write_zeroes} function signatures
  changed, to using int64_t for offsets/bytes and some still had int
  rather than BrdvRequestFlags for the flags.
* job_cancel_sync now has a force parameter. Commit messages in
  73895f3838cd7fdaf185cf1dbc47be58844a966f
  4cfb3f05627ad82af473e7f7ae113c3884cd04e3
  sound like using force=true makes more sense.
* Added 3 patches coming in via qemu-stable tag, most important one is
  to work around a librbd issue.
* Added another 3 patches from qemu-devel to fix issue leading to
  crash when live migrating with iothread.
* cluster_size calculation helper changed (see patch pve/0026).
* QAPI's if conditionals now use 'CONFIG_FOO' rather than
  'defined(CONFIG_FOO)'

Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
2022-02-15 14:03:07 +01:00

44 lines
1.8 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Hanna Reitz <hreitz@redhat.com>
Date: Tue, 18 Jan 2022 17:59:59 +0100
Subject: [PATCH] block/io: Update BSC only if want_zero is true
We update the block-status cache whenever we get new information from a
bdrv_co_block_status() call to the block driver. However, if we have
passed want_zero=false to that call, it may flag areas containing zeroes
as data, and so we would update the block-status cache with wrong
information.
Therefore, we should not update the cache with want_zero=false.
Reported-by: Nir Soffer <nsoffer@redhat.com>
Fixes: 0bc329fbb00 ("block: block-status cache for data regions")
Reviewed-by: Nir Soffer <nsoffer@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220118170000.49423-2-hreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
block/io.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/block/io.c b/block/io.c
index bb0a254def..4e4cb556c5 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2497,8 +2497,12 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
* non-protocol nodes, and then it is never used. However, filling
* the cache requires an RCU update, so double check here to avoid
* such an update if possible.
+ *
+ * Check want_zero, because we only want to update the cache when we
+ * have accurate information about what is zero and what is data.
*/
- if (ret == (BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID) &&
+ if (want_zero &&
+ ret == (BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID) &&
QLIST_EMPTY(&bs->children))
{
/*