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block: Mark bdrv_skip_implicit_filters() and callers GRAPH_RDLOCK

Browse source 
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_skip_implicit_filters() need to hold a reader lock for the graph
because it calls bdrv_filter_child(), which accesses bs->file/backing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-8-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2023-10-27 17:53:16 +02:00
parent 372b69f503
commit 430da832af
4 changed files with 32 additions and 16 deletions
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28
block.c
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@ -4778,6 +4778,8 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state,
return 0;
}
bdrv_graph_rdlock_main_loop();
switch (qobject_type(value)) {
case QTYPE_QNULL:
assert(is_backing); /* The 'file' option does not allow a null value */
@ -4787,17 +4789,16 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state,
str = qstring_get_str(qobject_to(QString, value));
new_child_bs = bdrv_lookup_bs(NULL, str, errp);
if (new_child_bs == NULL) {
return -EINVAL;
ret = -EINVAL;
goto out_rdlock;
}
bdrv_graph_rdlock_main_loop();
has_child = bdrv_recurse_has_child(new_child_bs, bs);
bdrv_graph_rdunlock_main_loop();
if (has_child) {
error_setg(errp, "Making '%s' a %s child of '%s' would create a "
"cycle", str, child_name, bs->node_name);
return -EINVAL;
ret = -EINVAL;
goto out_rdlock;
}
break;
default:
@ -4809,18 +4810,21 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state,
}
if (old_child_bs == new_child_bs) {
return 0;
ret = 0;
goto out_rdlock;
}
if (old_child_bs) {
if (bdrv_skip_implicit_filters(old_child_bs) == new_child_bs) {
return 0;
ret = 0;
goto out_rdlock;
}
if (old_child_bs->implicit) {
error_setg(errp, "Cannot replace implicit %s child of %s",
child_name, bs->node_name);
return -EPERM;
ret = -EPERM;
goto out_rdlock;
}
}
@ -4831,7 +4835,8 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state,
*/
error_setg(errp, "'%s' is a %s filter node that does not support a "
"%s child", bs->node_name, bs->drv->format_name, child_name);
return -EINVAL;
ret = -EINVAL;
goto out_rdlock;
}
if (is_backing) {
@ -4852,6 +4857,7 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state,
aio_context_acquire(ctx);
}
bdrv_graph_rdunlock_main_loop();
bdrv_graph_wrlock(new_child_bs);
ret = bdrv_set_file_or_backing_noperm(bs, new_child_bs, is_backing,
@ -4870,6 +4876,10 @@ bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state,
}
return ret;
out_rdlock:
bdrv_graph_rdunlock_main_loop();
return ret;
}
/*