From: Hanna Reitz <hreitz@redhat.com>
To: qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
qemu-devel@nongnu.org
Subject: [PATCH 1/7] stream: Traverse graph after modification
Date: Thu, 4 Nov 2021 11:38:43 +0100 [thread overview]
Message-ID: <20211104103849.46855-2-hreitz@redhat.com> (raw)
In-Reply-To: <20211104103849.46855-1-hreitz@redhat.com>
bdrv_cor_filter_drop() modifies the block graph. That means that other
parties can also modify the block graph before it returns. Therefore,
we cannot assume that the result of a graph traversal we did before
remains valid afterwards.
We should thus fetch `base` and `unfiltered_base` afterwards instead of
before.
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
---
block/stream.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/block/stream.c b/block/stream.c
index 97bee482dc..e45113aed6 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -54,8 +54,8 @@ static int stream_prepare(Job *job)
{
StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
BlockDriverState *unfiltered_bs = bdrv_skip_filters(s->target_bs);
- BlockDriverState *base = bdrv_filter_or_cow_bs(s->above_base);
- BlockDriverState *unfiltered_base = bdrv_skip_filters(base);
+ BlockDriverState *base;
+ BlockDriverState *unfiltered_base;
Error *local_err = NULL;
int ret = 0;
@@ -63,6 +63,9 @@ static int stream_prepare(Job *job)
bdrv_cor_filter_drop(s->cor_filter_bs);
s->cor_filter_bs = NULL;
+ base = bdrv_filter_or_cow_bs(s->above_base);
+ unfiltered_base = bdrv_skip_filters(base);
+
if (bdrv_cow_child(unfiltered_bs)) {
const char *base_id = NULL, *base_fmt = NULL;
if (unfiltered_base) {
--
2.33.1
next prev parent reply other threads:[~2021-11-04 10:42 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-04 10:38 [PATCH 0/7] block: Attempt on fixing 030-reported errors Hanna Reitz
2021-11-04 10:38 ` Hanna Reitz [this message]
2021-11-10 12:17 ` [PATCH 1/7] stream: Traverse graph after modification Vladimir Sementsov-Ogievskiy
2021-11-04 10:38 ` [PATCH 2/7] block: Manipulate children list in .attach/.detach Hanna Reitz
2021-11-10 12:46 ` Vladimir Sementsov-Ogievskiy
2021-11-10 15:05 ` Hanna Reitz
2021-11-10 12:51 ` Vladimir Sementsov-Ogievskiy
2021-11-10 15:12 ` Hanna Reitz
2021-11-04 10:38 ` [PATCH 3/7] block: Unite remove_empty_child and child_free Hanna Reitz
2021-11-10 12:52 ` Vladimir Sementsov-Ogievskiy
2021-11-04 10:38 ` [PATCH 4/7] block: Drop detached child from ignore list Hanna Reitz
2021-11-10 13:38 ` Vladimir Sementsov-Ogievskiy via
2021-11-10 17:32 ` Hanna Reitz
2021-11-04 10:38 ` [PATCH 5/7] block: Pass BdrvChild ** to replace_child_noperm Hanna Reitz
2021-11-05 15:15 ` Kevin Wolf
2021-11-08 9:58 ` Hanna Reitz
2021-11-04 10:38 ` [PATCH 6/7] block: Let replace_child_noperm free children Hanna Reitz
2021-11-05 15:41 ` Kevin Wolf
2021-11-08 10:12 ` Hanna Reitz
2021-11-04 10:38 ` [PATCH 7/7] iotests/030: Unthrottle parallel jobs in reverse Hanna Reitz
2021-11-04 11:58 ` [PATCH 0/7] block: Attempt on fixing 030-reported errors Kevin Wolf
2021-11-04 13:34 ` Hanna Reitz
2021-11-05 15:44 ` Kevin Wolf
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