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[PATCH 85/97] blockjob: update nodes head while removing all bdrv
From: |
Michael Roth |
Subject: |
[PATCH 85/97] blockjob: update nodes head while removing all bdrv |
Date: |
Tue, 1 Oct 2019 18:46:04 -0500 |
From: Sergio Lopez <address@hidden>
block_job_remove_all_bdrv() iterates through job->nodes, calling
bdrv_root_unref_child() for each entry. The call to the latter may
reach child_job_[can_]set_aio_ctx(), which will also attempt to
traverse job->nodes, potentially finding entries that where freed
on previous iterations.
To avoid this situation, update job->nodes head on each iteration to
ensure that already freed entries are no longer linked to the list.
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1746631
Signed-off-by: Sergio Lopez <address@hidden>
Cc: address@hidden
Signed-off-by: Max Reitz <address@hidden>
Message-id: address@hidden
Reviewed-by: Sergio Lopez <address@hidden>
Signed-off-by: Max Reitz <address@hidden>
(cherry picked from commit d876bf676f5e7c6aa9ac64555e48cba8734ecb2f)
Signed-off-by: Michael Roth <address@hidden>
---
blockjob.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/blockjob.c b/blockjob.c
index 730101d282..d770144fd6 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -193,14 +193,23 @@ static const BdrvChildRole child_job = {
void block_job_remove_all_bdrv(BlockJob *job)
{
- GSList *l;
- for (l = job->nodes; l; l = l->next) {
+ /*
+ * bdrv_root_unref_child() may reach child_job_[can_]set_aio_ctx(),
+ * which will also traverse job->nodes, so consume the list one by
+ * one to make sure that such a concurrent access does not attempt
+ * to process an already freed BdrvChild.
+ */
+ while (job->nodes) {
+ GSList *l = job->nodes;
BdrvChild *c = l->data;
+
+ job->nodes = l->next;
+
bdrv_op_unblock_all(c->bs, job->blocker);
bdrv_root_unref_child(c);
+
+ g_slist_free_1(l);
}
- g_slist_free(job->nodes);
- job->nodes = NULL;
}
int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
--
2.17.1
- [PATCH 81/97] iotests: Test blockdev-create for vpc, (continued)
- [PATCH 81/97] iotests: Test blockdev-create for vpc, Michael Roth, 2019/10/01
- [PATCH 06/97] block: Fix AioContext switch for bs->drv == NULL, Michael Roth, 2019/10/01
- [PATCH 84/97] block/nfs: tear down aio before nfs_close, Michael Roth, 2019/10/01
- [PATCH 61/97] block/backup: unify different modes code path, Michael Roth, 2019/10/01
- [PATCH 67/97] mirror: Only mirror granularity-aligned chunks, Michael Roth, 2019/10/01
- [PATCH 60/97] block/backup: refactor and tolerate unallocated cluster skipping, Michael Roth, 2019/10/01
- [PATCH 77/97] vpc: Return 0 from vpc_co_create() on success, Michael Roth, 2019/10/01
- [PATCH 86/97] curl: Keep pointer to the CURLState in CURLSocket, Michael Roth, 2019/10/01
- [PATCH 87/97] curl: Keep *socket until the end of curl_sock_cb(), Michael Roth, 2019/10/01
- [PATCH 76/97] iotests: add testing shim for script-style python tests, Michael Roth, 2019/10/01
- [PATCH 85/97] blockjob: update nodes head while removing all bdrv,
Michael Roth <=
- [PATCH 89/97] curl: Pass CURLSocket to curl_multi_do(), Michael Roth, 2019/10/01
- [PATCH 92/97] curl: Check curl_multi_add_handle()'s return code, Michael Roth, 2019/10/01
- [PATCH 91/97] curl: Handle success in multi_check_completion, Michael Roth, 2019/10/01
- [PATCH 63/97] backup: Copy only dirty areas, Michael Roth, 2019/10/01
- [PATCH 23/97] iotests: add iotest 256 for testing blockdev-backup across iothread contexts, Michael Roth, 2019/10/01
- [PATCH 09/97] docs/interop/bitmaps: rewrite and modernize doc, Michael Roth, 2019/10/01
- [PATCH 19/97] iotests.py: do not use infinite waits, Michael Roth, 2019/10/01
- Re: [PATCH 00/97] Patch Round-up for stable 4.0.1, freeze on 2019-10-10, Thomas Huth, 2019/10/02
- Re: [PATCH 00/97] Patch Round-up for stable 4.0.1, freeze on 2019-10-10, Philippe Mathieu-Daudé, 2019/10/03