mirror of https://github.com/proxmox/mirror_qemu
blockjob: update nodes head while removing all bdrv
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 <slp@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190911100316.32282-1-mreitz@redhat.com
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
(cherry picked from commit d876bf676f
)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
parent
2d86df1f78
commit
86b0f4022b
17
blockjob.c
17
blockjob.c
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@ -186,14 +186,23 @@ static const BdrvChildRole child_job = {
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void block_job_remove_all_bdrv(BlockJob *job)
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{
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GSList *l;
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for (l = job->nodes; l; l = l->next) {
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/*
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* bdrv_root_unref_child() may reach child_job_[can_]set_aio_ctx(),
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* which will also traverse job->nodes, so consume the list one by
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* one to make sure that such a concurrent access does not attempt
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* to process an already freed BdrvChild.
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*/
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while (job->nodes) {
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GSList *l = job->nodes;
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BdrvChild *c = l->data;
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job->nodes = l->next;
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bdrv_op_unblock_all(c->bs, job->blocker);
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bdrv_root_unref_child(c);
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g_slist_free_1(l);
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}
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g_slist_free(job->nodes);
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job->nodes = NULL;
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}
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bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs)
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