static BlockDriver bdrv_pass_through = {
.format_name = "pass-through",
+ .is_filter = true,
+ .filtered_child_is_backing = true,
.bdrv_child_perm = bdrv_default_perms,
};
static BlockDriver bdrv_no_perm = {
.format_name = "no-perm",
+ .supports_backing = true,
.bdrv_child_perm = no_perm_default_perms,
};
static BlockDriver bdrv_exclusive_writer = {
.format_name = "exclusive-writer",
+ .is_filter = true,
+ .filtered_child_is_backing = true,
.bdrv_child_perm = exclusive_write_perms,
};
* | perm: write, read
* | shared: except write
* v
- * +-------------------+ +----------------+
- * | passtrough filter |---------->| null-co node |
- * +-------------------+ +----------------+
+ * +--------------------+ +----------------+
+ * | passthrough filter |--------->| null-co node |
+ * +--------------------+ +----------------+
*
*
* and then, tries to append filter under node. Expected behavior: fail.
* | perm: write, read
* | shared: except write
* v
- * +-------------------+
- * | passtrough filter |
- * +-------------------+
+ * +--------------------+
+ * | passthrough filter |
+ * +--------------------+
* | |
* perm: write, read | | perm: write, read
* shared: except write | | shared: except write
blk_insert_bs(root, bs, &error_abort);
+ bdrv_graph_wrlock(NULL);
bdrv_attach_child(filter, bs, "child", &child_of_bds,
- BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, &error_abort);
+ BDRV_CHILD_DATA, &error_abort);
+ bdrv_graph_wrunlock(NULL);
+ aio_context_acquire(qemu_get_aio_context());
ret = bdrv_append(filter, bs, NULL);
g_assert_cmpint(ret, <, 0);
+ aio_context_release(qemu_get_aio_context());
bdrv_unref(filter);
blk_unref(root);
bdrv_set_backing_hd(target, bs, &error_abort);
+ bdrv_graph_wrlock(NULL);
g_assert(target->backing->bs == bs);
bdrv_attach_child(filter, target, "target", &child_of_bds,
BDRV_CHILD_DATA, &error_abort);
+ bdrv_graph_wrunlock(NULL);
+ aio_context_acquire(qemu_get_aio_context());
bdrv_append(filter, bs, &error_abort);
+ aio_context_release(qemu_get_aio_context());
+
+ bdrv_graph_rdlock_main_loop();
g_assert(target->backing->bs == bs);
+ bdrv_graph_rdunlock_main_loop();
bdrv_unref(filter);
bdrv_unref(bs);
BlockDriverState *fl1 = pass_through_node("fl1");
BlockDriverState *fl2 = pass_through_node("fl2");
+ bdrv_drained_begin(fl1);
+ bdrv_drained_begin(fl2);
+
/*
* bdrv_attach_child() eats child bs reference, so we need two @base
- * references for two filters:
+ * references for two filters. We also need an additional @fl1 reference so
+ * that it still exists when we want to undrain it.
*/
bdrv_ref(base);
+ bdrv_ref(fl1);
- bdrv_attach_child(top, fl1, "backing", &child_of_bds, BDRV_CHILD_DATA,
+ bdrv_graph_wrlock(NULL);
+ bdrv_attach_child(top, fl1, "backing", &child_of_bds,
+ BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
&error_abort);
- bdrv_attach_child(fl1, base, "backing", &child_of_bds, BDRV_CHILD_FILTERED,
+ bdrv_attach_child(fl1, base, "backing", &child_of_bds,
+ BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
&error_abort);
- bdrv_attach_child(fl2, base, "backing", &child_of_bds, BDRV_CHILD_FILTERED,
+ bdrv_attach_child(fl2, base, "backing", &child_of_bds,
+ BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
&error_abort);
bdrv_replace_node(fl1, fl2, &error_abort);
+ bdrv_graph_wrunlock(NULL);
+ bdrv_drained_end(fl2);
+ bdrv_drained_end(fl1);
+
+ bdrv_unref(fl1);
bdrv_unref(fl2);
bdrv_unref(top);
}
-static void write_to_file_perms(BlockDriverState *bs, BdrvChild *c,
- BdrvChildRole role,
- BlockReopenQueue *reopen_queue,
- uint64_t perm, uint64_t shared,
- uint64_t *nperm, uint64_t *nshared)
+/*
+ * write-to-selected node may have several DATA children, one of them may be
+ * "selected". Exclusive write permission is taken on selected child.
+ *
+ * We don't realize write handler itself, as we need only to test how permission
+ * update works.
+ */
+typedef struct BDRVWriteToSelectedState {
+ BdrvChild *selected;
+} BDRVWriteToSelectedState;
+
+static void write_to_selected_perms(BlockDriverState *bs, BdrvChild *c,
+ BdrvChildRole role,
+ BlockReopenQueue *reopen_queue,
+ uint64_t perm, uint64_t shared,
+ uint64_t *nperm, uint64_t *nshared)
{
- if (bs->file && c == bs->file) {
+ BDRVWriteToSelectedState *s = bs->opaque;
+
+ if (s->selected && c == s->selected) {
*nperm = BLK_PERM_WRITE;
*nshared = BLK_PERM_ALL & ~BLK_PERM_WRITE;
} else {
}
}
-static BlockDriver bdrv_write_to_file = {
- .format_name = "tricky-perm",
- .bdrv_child_perm = write_to_file_perms,
+static BlockDriver bdrv_write_to_selected = {
+ .format_name = "write-to-selected",
+ .instance_size = sizeof(BDRVWriteToSelectedState),
+ .bdrv_child_perm = write_to_selected_perms,
};
* The following test shows that topological-sort order is required for
* permission update, simple DFS is not enough.
*
- * Consider the block driver which has two filter children: one active
- * with exclusive write access and one inactive with no specific
- * permissions.
+ * Consider the block driver (write-to-selected) which has two children: one is
+ * selected so we have exclusive write access to it and for the other one we
+ * don't need any specific permissions.
*
* And, these two children has a common base child, like this:
+ * (additional "top" on top is used in test just because the only public
+ * function to update permission should get a specific child to update.
+ * Making bdrv_refresh_perms() public just for this test isn't worth it)
*
- * ┌─────┐ ┌──────┐
- * │ fl2 │ ◀── │ top │
- * └─────┘ └──────┘
+ * â\94\8câ\94\80â\94\80â\94\80â\94\80â\94\80â\94\90 â\94\8câ\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\90 â\94\8câ\94\80â\94\80â\94\80â\94\80â\94\80â\94\90
+ * │ fl2 │ ◀── │ write-to-selected │ ◀── │ top │
+ * â\94\94â\94\80â\94\80â\94\80â\94\80â\94\80â\94\98 â\94\94â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\80â\94\98 â\94\94â\94\80â\94\80â\94\80â\94\80â\94\80â\94\98
* │ │
* │ │ w
* │ ▼
*
* So, exclusive write is propagated.
*
- * Assume, we want to make fl2 active instead of fl1.
- * So, we set some option for top driver and do permission update.
+ * Assume, we want to select fl2 instead of fl1.
+ * So, we set some option for write-to-selected driver and do permission update.
*
* With simple DFS, if permission update goes first through
- * top->fl1->base branch it will succeed: it firstly drop exclusive write
- * permissions and than apply them for another BdrvChildren.
- * But if permission update goes first through top->fl2->base branch it
- * will fail, as when we try to update fl2->base child, old not yet
+ * write-to-selected -> fl1 -> base branch it will succeed: it firstly drop
+ * exclusive write permissions and than apply them for another BdrvChildren.
+ * But if permission update goes first through write-to-selected -> fl2 -> base
+ * branch it will fail, as when we try to update fl2->base child, old not yet
* updated fl1->base child will be in conflict.
*
* With topological-sort order we always update parents before children, so fl1
static void test_parallel_perm_update(void)
{
BlockDriverState *top = no_perm_node("top");
- BlockDriverState *tricky =
- bdrv_new_open_driver(&bdrv_write_to_file, "tricky", BDRV_O_RDWR,
+ BlockDriverState *ws =
+ bdrv_new_open_driver(&bdrv_write_to_selected, "ws", BDRV_O_RDWR,
&error_abort);
+ BDRVWriteToSelectedState *s = ws->opaque;
BlockDriverState *base = no_perm_node("base");
BlockDriverState *fl1 = pass_through_node("fl1");
BlockDriverState *fl2 = pass_through_node("fl2");
*/
bdrv_ref(base);
- bdrv_attach_child(top, tricky, "file", &child_of_bds, BDRV_CHILD_DATA,
+ bdrv_graph_wrlock(NULL);
+ bdrv_attach_child(top, ws, "file", &child_of_bds, BDRV_CHILD_DATA,
&error_abort);
- c_fl1 = bdrv_attach_child(tricky, fl1, "first", &child_of_bds,
- BDRV_CHILD_FILTERED, &error_abort);
- c_fl2 = bdrv_attach_child(tricky, fl2, "second", &child_of_bds,
- BDRV_CHILD_FILTERED, &error_abort);
- bdrv_attach_child(fl1, base, "backing", &child_of_bds, BDRV_CHILD_FILTERED,
+ c_fl1 = bdrv_attach_child(ws, fl1, "first", &child_of_bds,
+ BDRV_CHILD_DATA, &error_abort);
+ c_fl2 = bdrv_attach_child(ws, fl2, "second", &child_of_bds,
+ BDRV_CHILD_DATA, &error_abort);
+ bdrv_attach_child(fl1, base, "backing", &child_of_bds,
+ BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
&error_abort);
- bdrv_attach_child(fl2, base, "backing", &child_of_bds, BDRV_CHILD_FILTERED,
+ bdrv_attach_child(fl2, base, "backing", &child_of_bds,
+ BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
&error_abort);
+ bdrv_graph_wrunlock(NULL);
/* Select fl1 as first child to be active */
- tricky->file = c_fl1;
+ s->selected = c_fl1;
+
+ bdrv_graph_rdlock_main_loop();
+
bdrv_child_refresh_perms(top, top->children.lh_first, &error_abort);
assert(c_fl1->perm & BLK_PERM_WRITE);
assert(!(c_fl2->perm & BLK_PERM_WRITE));
/* Now, try to switch active child and update permissions */
- tricky->file = c_fl2;
+ s->selected = c_fl2;
bdrv_child_refresh_perms(top, top->children.lh_first, &error_abort);
assert(c_fl2->perm & BLK_PERM_WRITE);
assert(!(c_fl1->perm & BLK_PERM_WRITE));
/* Switch once more, to not care about real child order in the list */
- tricky->file = c_fl1;
+ s->selected = c_fl1;
bdrv_child_refresh_perms(top, top->children.lh_first, &error_abort);
assert(c_fl1->perm & BLK_PERM_WRITE);
assert(!(c_fl2->perm & BLK_PERM_WRITE));
+ bdrv_graph_rdunlock_main_loop();
bdrv_unref(top);
}
BlockDriverState *base = no_perm_node("base");
BlockDriverState *fl = exclusive_writer_node("fl1");
- bdrv_attach_child(top, base, "backing", &child_of_bds, BDRV_CHILD_COW,
+ bdrv_graph_wrlock(NULL);
+ bdrv_attach_child(top, base, "backing", &child_of_bds,
+ BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
&error_abort);
+ bdrv_graph_wrunlock(NULL);
+ aio_context_acquire(qemu_get_aio_context());
bdrv_append(fl, base, &error_abort);
+ aio_context_release(qemu_get_aio_context());
bdrv_unref(fl);
bdrv_unref(top);
}
int main(int argc, char *argv[])
{
- int i;
- bool debug = false;
-
- for (i = 1; i < argc; i++) {
- if (!strcmp(argv[i], "-d")) {
- debug = true;
- break;
- }
- }
-
bdrv_init();
qemu_init_main_loop(&error_abort);
test_should_update_child);
g_test_add_func("/bdrv-graph-mod/parallel-perm-update",
test_parallel_perm_update);
-
- if (debug) {
- g_test_add_func("/bdrv-graph-mod/parallel-exclusive-write",
- test_parallel_exclusive_write);
- g_test_add_func("/bdrv-graph-mod/append-greedy-filter",
- test_append_greedy_filter);
- }
+ g_test_add_func("/bdrv-graph-mod/parallel-exclusive-write",
+ test_parallel_exclusive_write);
+ g_test_add_func("/bdrv-graph-mod/append-greedy-filter",
+ test_append_greedy_filter);
return g_test_run();
}