diff options
Diffstat (limited to 'tests/unit')
| -rw-r--r-- | tests/unit/test-bdrv-graph-mod.c | 80 |
1 files changed, 49 insertions, 31 deletions
diff --git a/tests/unit/test-bdrv-graph-mod.c b/tests/unit/test-bdrv-graph-mod.c index a6e3bb7..e2f1355 100644 --- a/tests/unit/test-bdrv-graph-mod.c +++ b/tests/unit/test-bdrv-graph-mod.c @@ -241,13 +241,26 @@ static void test_parallel_exclusive_write(void) 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 { @@ -256,9 +269,10 @@ static void write_to_file_perms(BlockDriverState *bs, BdrvChild *c, } } -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, }; @@ -266,15 +280,18 @@ static BlockDriver bdrv_write_to_file = { * 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 │ - * └─────┘ └──────┘ + * ┌─────┐ ┌───────────────────┐ ┌─────┐ + * │ fl2 │ ◀── │ write-to-selected │ ◀── │ top │ + * └─────┘ └───────────────────┘ └─────┘ * │ │ * │ │ w * │ ▼ @@ -290,14 +307,14 @@ static BlockDriver bdrv_write_to_file = { * * 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 @@ -306,9 +323,10 @@ static BlockDriver bdrv_write_to_file = { 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"); @@ -320,33 +338,33 @@ static void test_parallel_perm_update(void) */ bdrv_ref(base); - bdrv_attach_child(top, tricky, "file", &child_of_bds, BDRV_CHILD_DATA, + 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); + 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, &error_abort); bdrv_attach_child(fl2, base, "backing", &child_of_bds, BDRV_CHILD_FILTERED, &error_abort); /* Select fl1 as first child to be active */ - 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)); /* 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); |