block: Mark block_job_add_bdrv() GRAPH_WRLOCK
Instead of taking the writer lock internally, require callers to already
hold it when calling block_job_add_bdrv(). These callers will typically
already hold the graph lock once the locking work is completed, which
means that they can't call functions that take it internally.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-6-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/commit.c b/block/commit.c
index 43d1de7..fc3ad79 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -342,6 +342,7 @@
*/
iter_shared_perms = BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE;
+ bdrv_graph_wrlock(top);
for (iter = top; iter != base; iter = bdrv_filter_or_cow_bs(iter)) {
if (iter == filtered_base) {
/*
@@ -354,16 +355,20 @@
ret = block_job_add_bdrv(&s->common, "intermediate node", iter, 0,
iter_shared_perms, errp);
if (ret < 0) {
+ bdrv_graph_wrunlock();
goto fail;
}
}
if (bdrv_freeze_backing_chain(commit_top_bs, base, errp) < 0) {
+ bdrv_graph_wrunlock();
goto fail;
}
s->chain_frozen = true;
ret = block_job_add_bdrv(&s->common, "base", base, 0, BLK_PERM_ALL, errp);
+ bdrv_graph_wrunlock();
+
if (ret < 0) {
goto fail;
}