1/* 2 * Block node graph modifications tests 3 * 4 * Copyright (c) 2019 Virtuozzo International GmbH. All rights reserved. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 * 19 */ 20 21#include "qemu/osdep.h" 22#include "qapi/error.h" 23#include "block/block_int.h" 24#include "sysemu/block-backend.h" 25 26static BlockDriver bdrv_pass_through = { 27 .format_name = "pass-through", 28 .bdrv_child_perm = bdrv_filter_default_perms, 29}; 30 31static void no_perm_default_perms(BlockDriverState *bs, BdrvChild *c, 32 const BdrvChildRole *role, 33 BlockReopenQueue *reopen_queue, 34 uint64_t perm, uint64_t shared, 35 uint64_t *nperm, uint64_t *nshared) 36{ 37 *nperm = 0; 38 *nshared = BLK_PERM_ALL; 39} 40 41static BlockDriver bdrv_no_perm = { 42 .format_name = "no-perm", 43 .bdrv_child_perm = no_perm_default_perms, 44}; 45 46static BlockDriverState *no_perm_node(const char *name) 47{ 48 return bdrv_new_open_driver(&bdrv_no_perm, name, BDRV_O_RDWR, &error_abort); 49} 50 51static BlockDriverState *pass_through_node(const char *name) 52{ 53 return bdrv_new_open_driver(&bdrv_pass_through, name, 54 BDRV_O_RDWR, &error_abort); 55} 56 57/* 58 * test_update_perm_tree 59 * 60 * When checking node for a possibility to update permissions, it's subtree 61 * should be correctly checked too. New permissions for each node should be 62 * calculated and checked in context of permissions of other nodes. If we 63 * check new permissions of the node only in context of old permissions of 64 * its neighbors, we can finish up with wrong permission graph. 65 * 66 * This test firstly create the following graph: 67 * +--------+ 68 * | root | 69 * +--------+ 70 * | 71 * | perm: write, read 72 * | shared: except write 73 * v 74 * +-------------------+ +----------------+ 75 * | passtrough filter |---------->| null-co node | 76 * +-------------------+ +----------------+ 77 * 78 * 79 * and then, tries to append filter under node. Expected behavior: fail. 80 * Otherwise we'll get the following picture, with two BdrvChild'ren, having 81 * write permission to one node, without actually sharing it. 82 * 83 * +--------+ 84 * | root | 85 * +--------+ 86 * | 87 * | perm: write, read 88 * | shared: except write 89 * v 90 * +-------------------+ 91 * | passtrough filter | 92 * +-------------------+ 93 * | | 94 * perm: write, read | | perm: write, read 95 * shared: except write | | shared: except write 96 * v v 97 * +----------------+ 98 * | null co node | 99 * +----------------+ 100 */ 101static void test_update_perm_tree(void) 102{ 103 Error *local_err = NULL; 104 105 BlockBackend *root = blk_new(BLK_PERM_WRITE | BLK_PERM_CONSISTENT_READ, 106 BLK_PERM_ALL & ~BLK_PERM_WRITE); 107 BlockDriverState *bs = no_perm_node("node"); 108 BlockDriverState *filter = pass_through_node("filter"); 109 110 blk_insert_bs(root, bs, &error_abort); 111 112 bdrv_attach_child(filter, bs, "child", &child_file, &error_abort); 113 114 bdrv_append(filter, bs, &local_err); 115 116 g_assert_nonnull(local_err); 117 error_free(local_err); 118 119 bdrv_unref(bs); 120 blk_unref(root); 121} 122 123/* 124 * test_should_update_child 125 * 126 * Test that bdrv_replace_node, and concretely should_update_child 127 * do the right thing, i.e. not creating loops on the graph. 128 * 129 * The test does the following: 130 * 1. initial graph: 131 * 132 * +------+ +--------+ 133 * | root | | filter | 134 * +------+ +--------+ 135 * | | 136 * root| target| 137 * v v 138 * +------+ +--------+ 139 * | node |<---------| target | 140 * +------+ backing +--------+ 141 * 142 * 2. Append @filter above @node. If should_update_child works correctly, 143 * it understands, that backing child of @target should not be updated, 144 * as it will create a loop on node graph. Resulting picture should 145 * be the left one, not the right: 146 * 147 * +------+ +------+ 148 * | root | | root | 149 * +------+ +------+ 150 * | | 151 * root| root| 152 * v v 153 * +--------+ target +--------+ target 154 * | filter |--------------+ | filter |--------------+ 155 * +--------+ | +--------+ | 156 * | | | ^ v 157 * backing| | backing| | +--------+ 158 * v v | +-----------| target | 159 * +------+ +--------+ v backing +--------+ 160 * | node |<---------| target | +------+ 161 * +------+ backing +--------+ | node | 162 * +------+ 163 * 164 * (good picture) (bad picture) 165 * 166 */ 167static void test_should_update_child(void) 168{ 169 BlockBackend *root = blk_new(0, BLK_PERM_ALL); 170 BlockDriverState *bs = no_perm_node("node"); 171 BlockDriverState *filter = no_perm_node("filter"); 172 BlockDriverState *target = no_perm_node("target"); 173 174 blk_insert_bs(root, bs, &error_abort); 175 176 bdrv_set_backing_hd(target, bs, &error_abort); 177 178 g_assert(target->backing->bs == bs); 179 bdrv_attach_child(filter, target, "target", &child_file, &error_abort); 180 bdrv_append(filter, bs, &error_abort); 181 g_assert(target->backing->bs == bs); 182 183 bdrv_unref(bs); 184 blk_unref(root); 185} 186 187int main(int argc, char *argv[]) 188{ 189 bdrv_init(); 190 qemu_init_main_loop(&error_abort); 191 192 g_test_init(&argc, &argv, NULL); 193 194 g_test_add_func("/bdrv-graph-mod/update-perm-tree", test_update_perm_tree); 195 g_test_add_func("/bdrv-graph-mod/should-update-child", 196 test_should_update_child); 197 198 return g_test_run(); 199} 200