qemu/tests/test-bdrv-graph-mod.c
Kevin Wolf d861ab3acf block: Add BlockBackend.ctx
This adds a new parameter to blk_new() which requires its callers to
declare from which AioContext this BlockBackend is going to be used (or
the locks of which AioContext need to be taken anyway).

The given context is only stored and kept up to date when changing
AioContexts. Actually applying the stored AioContext to the root node
is saved for another commit.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 15:22:22 +02:00

200 lines
6.9 KiB
C

/*
* Block node graph modifications tests
*
* Copyright (c) 2019 Virtuozzo International GmbH. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "block/block_int.h"
#include "sysemu/block-backend.h"
static BlockDriver bdrv_pass_through = {
.format_name = "pass-through",
.bdrv_child_perm = bdrv_filter_default_perms,
};
static void no_perm_default_perms(BlockDriverState *bs, BdrvChild *c,
const BdrvChildRole *role,
BlockReopenQueue *reopen_queue,
uint64_t perm, uint64_t shared,
uint64_t *nperm, uint64_t *nshared)
{
*nperm = 0;
*nshared = BLK_PERM_ALL;
}
static BlockDriver bdrv_no_perm = {
.format_name = "no-perm",
.bdrv_child_perm = no_perm_default_perms,
};
static BlockDriverState *no_perm_node(const char *name)
{
return bdrv_new_open_driver(&bdrv_no_perm, name, BDRV_O_RDWR, &error_abort);
}
static BlockDriverState *pass_through_node(const char *name)
{
return bdrv_new_open_driver(&bdrv_pass_through, name,
BDRV_O_RDWR, &error_abort);
}
/*
* test_update_perm_tree
*
* When checking node for a possibility to update permissions, it's subtree
* should be correctly checked too. New permissions for each node should be
* calculated and checked in context of permissions of other nodes. If we
* check new permissions of the node only in context of old permissions of
* its neighbors, we can finish up with wrong permission graph.
*
* This test firstly create the following graph:
* +--------+
* | root |
* +--------+
* |
* | perm: write, read
* | shared: except write
* v
* +-------------------+ +----------------+
* | passtrough filter |---------->| null-co node |
* +-------------------+ +----------------+
*
*
* and then, tries to append filter under node. Expected behavior: fail.
* Otherwise we'll get the following picture, with two BdrvChild'ren, having
* write permission to one node, without actually sharing it.
*
* +--------+
* | root |
* +--------+
* |
* | perm: write, read
* | shared: except write
* v
* +-------------------+
* | passtrough filter |
* +-------------------+
* | |
* perm: write, read | | perm: write, read
* shared: except write | | shared: except write
* v v
* +----------------+
* | null co node |
* +----------------+
*/
static void test_update_perm_tree(void)
{
Error *local_err = NULL;
BlockBackend *root = blk_new(qemu_get_aio_context(),
BLK_PERM_WRITE | BLK_PERM_CONSISTENT_READ,
BLK_PERM_ALL & ~BLK_PERM_WRITE);
BlockDriverState *bs = no_perm_node("node");
BlockDriverState *filter = pass_through_node("filter");
blk_insert_bs(root, bs, &error_abort);
bdrv_attach_child(filter, bs, "child", &child_file, &error_abort);
bdrv_append(filter, bs, &local_err);
g_assert_nonnull(local_err);
error_free(local_err);
blk_unref(root);
}
/*
* test_should_update_child
*
* Test that bdrv_replace_node, and concretely should_update_child
* do the right thing, i.e. not creating loops on the graph.
*
* The test does the following:
* 1. initial graph:
*
* +------+ +--------+
* | root | | filter |
* +------+ +--------+
* | |
* root| target|
* v v
* +------+ +--------+
* | node |<---------| target |
* +------+ backing +--------+
*
* 2. Append @filter above @node. If should_update_child works correctly,
* it understands, that backing child of @target should not be updated,
* as it will create a loop on node graph. Resulting picture should
* be the left one, not the right:
*
* +------+ +------+
* | root | | root |
* +------+ +------+
* | |
* root| root|
* v v
* +--------+ target +--------+ target
* | filter |--------------+ | filter |--------------+
* +--------+ | +--------+ |
* | | | ^ v
* backing| | backing| | +--------+
* v v | +-----------| target |
* +------+ +--------+ v backing +--------+
* | node |<---------| target | +------+
* +------+ backing +--------+ | node |
* +------+
*
* (good picture) (bad picture)
*
*/
static void test_should_update_child(void)
{
BlockBackend *root = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
BlockDriverState *bs = no_perm_node("node");
BlockDriverState *filter = no_perm_node("filter");
BlockDriverState *target = no_perm_node("target");
blk_insert_bs(root, bs, &error_abort);
bdrv_set_backing_hd(target, bs, &error_abort);
g_assert(target->backing->bs == bs);
bdrv_attach_child(filter, target, "target", &child_file, &error_abort);
bdrv_append(filter, bs, &error_abort);
g_assert(target->backing->bs == bs);
bdrv_unref(bs);
blk_unref(root);
}
int main(int argc, char *argv[])
{
bdrv_init();
qemu_init_main_loop(&error_abort);
g_test_init(&argc, &argv, NULL);
g_test_add_func("/bdrv-graph-mod/update-perm-tree", test_update_perm_tree);
g_test_add_func("/bdrv-graph-mod/should-update-child",
test_should_update_child);
return g_test_run();
}