diff options
Diffstat (limited to 'tests/test-bdrv-graph-mod.c')
| -rw-r--r-- | tests/test-bdrv-graph-mod.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/tests/test-bdrv-graph-mod.c b/tests/test-bdrv-graph-mod.c new file mode 100644 index 0000000000..458dfa6661 --- /dev/null +++ b/tests/test-bdrv-graph-mod.c @@ -0,0 +1,198 @@ +/* + * 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(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); + + bdrv_unref(bs); + 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(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(); +} |