Split out no-perm part of bdrv_root_attach_child() into separate
transaction action. bdrv_root_attach_child() now moves to new
permission update paradigm: first update graph relations then update
permissions.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
block.c | 189 ++++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 135 insertions(+), 54 deletions(-)
diff --git a/block.c b/block.c
index 98ff44dbf7..b6bdc534d2 100644
--- a/block.c
+++ b/block.c
@@ -2921,37 +2921,73 @@ static void bdrv_replace_child(BdrvChild *child,
BlockDriverState *new_bs)
}
}
-/*
- * This function steals the reference to child_bs from the caller.
- * That reference is later dropped by bdrv_root_unref_child().
- *
- * On failure NULL is returned, errp is set and the reference to
- * child_bs is also dropped.
- *
- * The caller must hold the AioContext lock @child_bs, but not that of @ctx
- * (unless @child_bs is already in @ctx).
- */
-BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
- const char *child_name,
- const BdrvChildClass *child_class,
- BdrvChildRole child_role,
- uint64_t perm, uint64_t shared_perm,
- void *opaque, Error **errp)
+static void bdrv_remove_empty_child(BdrvChild *child)
{
- BdrvChild *child;
- Error *local_err = NULL;
- int ret;
- AioContext *ctx;
+ assert(!child->bs);
+ QLIST_SAFE_REMOVE(child, next);
+ g_free(child->name);
+ g_free(child);
+}
- ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, errp);
- if (ret < 0) {
- bdrv_abort_perm_update(child_bs);
- bdrv_unref(child_bs);
- return NULL;
+typedef struct BdrvAttachChildCommonState {
+ BdrvChild **child;
+ AioContext *old_parent_ctx;
+ AioContext *old_child_ctx;
+} BdrvAttachChildCommonState;
+
+static void bdrv_attach_child_common_abort(void *opaque)
+{
+ BdrvAttachChildCommonState *s = opaque;
+ BdrvChild *child = *s->child;
+ BlockDriverState *bs = child->bs;
+
+ bdrv_replace_child_noperm(child, NULL);
+
+ if (bdrv_get_aio_context(bs) != s->old_child_ctx) {
+ bdrv_try_set_aio_context(bs, s->old_child_ctx, &error_abort);
}
- child = g_new(BdrvChild, 1);
- *child = (BdrvChild) {
+ if (bdrv_child_get_parent_aio_context(child) != s->old_parent_ctx) {
+ GSList *ignore = g_slist_prepend(NULL, child);
+
+ child->klass->can_set_aio_ctx(child, s->old_parent_ctx, &ignore,
+ &error_abort);
+ g_slist_free(ignore);
+ ignore = g_slist_prepend(NULL, child);
+ child->klass->set_aio_ctx(child, s->old_parent_ctx, &ignore);
+
+ g_slist_free(ignore);
+ }
+
+ bdrv_unref(bs);
+ bdrv_remove_empty_child(child);
+ *s->child = NULL;
+}
+
+static TransactionActionDrv bdrv_attach_child_common_drv = {
+ .abort = bdrv_attach_child_common_abort,
+};
+
+/*
+ * Common part of attoching bdrv child to bs or to blk or to job
+ */
+static int bdrv_attach_child_common(BlockDriverState *child_bs,
+ const char *child_name,
+ const BdrvChildClass *child_class,
+ BdrvChildRole child_role,
+ uint64_t perm, uint64_t shared_perm,
+ void *opaque, BdrvChild **child,
+ Transaction *tran, Error **errp)
+{
+ BdrvChild *new_child;
+ AioContext *parent_ctx;
+ AioContext *child_ctx = bdrv_get_aio_context(child_bs);
+
+ assert(child);
+ assert(*child == NULL);
+
+ new_child = g_new(BdrvChild, 1);
+ *new_child = (BdrvChild) {
.bs = NULL,
.name = g_strdup(child_name),
.klass = child_class,
@@ -2961,37 +2997,92 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState
*child_bs,
.opaque = opaque,
};
- ctx = bdrv_child_get_parent_aio_context(child);
-
- /* If the AioContexts don't match, first try to move the subtree of
+ /*
+ * If the AioContexts don't match, first try to move the subtree of
* child_bs into the AioContext of the new parent. If this doesn't work,
- * try moving the parent into the AioContext of child_bs instead. */
- if (bdrv_get_aio_context(child_bs) != ctx) {
- ret = bdrv_try_set_aio_context(child_bs, ctx, &local_err);
+ * try moving the parent into the AioContext of child_bs instead.
+ */
+ parent_ctx = bdrv_child_get_parent_aio_context(new_child);
+ if (child_ctx != parent_ctx) {
+ Error *local_err = NULL;
+ int ret = bdrv_try_set_aio_context(child_bs, parent_ctx, &local_err);
+
if (ret < 0 && child_class->can_set_aio_ctx) {
- GSList *ignore = g_slist_prepend(NULL, child);
- ctx = bdrv_get_aio_context(child_bs);
- if (child_class->can_set_aio_ctx(child, ctx, &ignore, NULL)) {
+ GSList *ignore = g_slist_prepend(NULL, new_child);
+ if (child_class->can_set_aio_ctx(new_child, child_ctx, &ignore,
+ NULL))
+ {
error_free(local_err);
ret = 0;
g_slist_free(ignore);
- ignore = g_slist_prepend(NULL, child);
- child_class->set_aio_ctx(child, ctx, &ignore);
+ ignore = g_slist_prepend(NULL, new_child);
+ child_class->set_aio_ctx(new_child, child_ctx, &ignore);
}
g_slist_free(ignore);
}
+
if (ret < 0) {
error_propagate(errp, local_err);
- g_free(child);
- bdrv_abort_perm_update(child_bs);
- bdrv_unref(child_bs);
- return NULL;
+ bdrv_remove_empty_child(new_child);
+ return ret;
}
}
- /* This performs the matching bdrv_set_perm() for the above check. */
- bdrv_replace_child(child, child_bs);
+ bdrv_ref(child_bs);
+ bdrv_replace_child_noperm(new_child, child_bs);
+
+ *child = new_child;
+ BdrvAttachChildCommonState *s = g_new(BdrvAttachChildCommonState, 1);
+ *s = (BdrvAttachChildCommonState) {
+ .child = child,
+ .old_parent_ctx = parent_ctx,
+ .old_child_ctx = child_ctx,
+ };
+ tran_add(tran, &bdrv_attach_child_common_drv, s);