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-rw-r--r--tests/Makefile.include2
-rw-r--r--tests/test-bdrv-graph-mod.c198
2 files changed, 200 insertions, 0 deletions
diff --git a/tests/Makefile.include b/tests/Makefile.include
index b39e989f72..992378e031 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -70,6 +70,7 @@ check-unit-y += tests/test-throttle$(EXESUF)
check-unit-y += tests/test-thread-pool$(EXESUF)
check-unit-y += tests/test-hbitmap$(EXESUF)
check-unit-y += tests/test-bdrv-drain$(EXESUF)
+check-unit-y += tests/test-bdrv-graph-mod$(EXESUF)
check-unit-y += tests/test-blockjob$(EXESUF)
check-unit-y += tests/test-blockjob-txn$(EXESUF)
check-unit-y += tests/test-block-backend$(EXESUF)
@@ -555,6 +556,7 @@ tests/test-aio$(EXESUF): tests/test-aio.o $(test-block-obj-y)
tests/test-aio-multithread$(EXESUF): tests/test-aio-multithread.o $(test-block-obj-y)
tests/test-throttle$(EXESUF): tests/test-throttle.o $(test-block-obj-y)
tests/test-bdrv-drain$(EXESUF): tests/test-bdrv-drain.o $(test-block-obj-y) $(test-util-obj-y)
+tests/test-bdrv-graph-mod$(EXESUF): tests/test-bdrv-graph-mod.o $(test-block-obj-y) $(test-util-obj-y)
tests/test-blockjob$(EXESUF): tests/test-blockjob.o $(test-block-obj-y) $(test-util-obj-y)
tests/test-blockjob-txn$(EXESUF): tests/test-blockjob-txn.o $(test-block-obj-y) $(test-util-obj-y)
tests/test-block-backend$(EXESUF): tests/test-block-backend.o $(test-block-obj-y) $(test-util-obj-y)
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();
+}