const char *node_name,
Error **errp)
{
- if (!node_name) {
- return;
- }
+ char *gen_node_name = NULL;
- /* Check for empty string or invalid characters */
- if (!id_wellformed(node_name)) {
+ if (!node_name) {
+ node_name = gen_node_name = id_generate(ID_BLOCK);
+ } else if (!id_wellformed(node_name)) {
+ /*
+ * Check for empty string or invalid characters, but not if it is
+ * generated (generated names use characters not available to the user)
+ */
error_setg(errp, "Invalid node name");
return;
}
if (blk_by_name(node_name)) {
error_setg(errp, "node-name=%s is conflicting with a device id",
node_name);
- return;
+ goto out;
}
/* takes care of avoiding duplicates node names */
if (bdrv_find_node(node_name)) {
error_setg(errp, "Duplicate node name");
- return;
+ goto out;
}
/* copy node name into the bs and insert it into the graph list */
pstrcpy(bs->node_name, sizeof(bs->node_name), node_name);
QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list);
+out:
+ g_free(gen_node_name);
}
static QemuOptsList bdrv_runtime_opts = {
return child;
}
-void bdrv_detach_child(BdrvChild *child)
+static void bdrv_detach_child(BdrvChild *child)
{
QLIST_REMOVE(child, next);
QLIST_REMOVE(child, next_parent);
void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
{
- BlockDriverState *child_bs = child->bs;
+ BlockDriverState *child_bs;
+
+ if (child == NULL) {
+ return;
+ }
if (child->bs->inherits_from == parent) {
child->bs->inherits_from = NULL;
}
+ child_bs = child->bs;
bdrv_detach_child(child);
bdrv_unref(child_bs);
}
bs->node_name[0] = '\0';
}
-static void bdrv_rebind(BlockDriverState *bs)
-{
- if (bs->drv && bs->drv->bdrv_rebind) {
- bs->drv->bdrv_rebind(bs);
- }
-}
-
-/* Fields that need to stay with the top-level BDS, no matter whether the
- * address of the top-level BDS stays the same or not. */
+/* Fields that need to stay with the top-level BDS */
static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
BlockDriverState *bs_src)
{
bs_dest->dirty_bitmaps = bs_src->dirty_bitmaps;
}
-/* Fields that only need to be swapped if the contents of BDSes is swapped
- * rather than pointers being changed in the parents, and throttling fields
- * because only bdrv_swap() messes with internals of throttling. */
-static void bdrv_move_reference_fields(BlockDriverState *bs_dest,
- BlockDriverState *bs_src)
-{
- /* i/o throttled req */
- bs_dest->throttle_state = bs_src->throttle_state,
- bs_dest->io_limits_enabled = bs_src->io_limits_enabled;
- bs_dest->pending_reqs[0] = bs_src->pending_reqs[0];
- bs_dest->pending_reqs[1] = bs_src->pending_reqs[1];
- bs_dest->throttled_reqs[0] = bs_src->throttled_reqs[0];
- bs_dest->throttled_reqs[1] = bs_src->throttled_reqs[1];
- memcpy(&bs_dest->round_robin,
- &bs_src->round_robin,
- sizeof(bs_dest->round_robin));
- memcpy(&bs_dest->throttle_timers,
- &bs_src->throttle_timers,
- sizeof(ThrottleTimers));
-
- /* reference count */
- bs_dest->refcnt = bs_src->refcnt;
-
- /* job */
- bs_dest->job = bs_src->job;
-
- /* keep the same entry in bdrv_states */
- bs_dest->device_list = bs_src->device_list;
- bs_dest->blk = bs_src->blk;
- bs_dest->parents = bs_src->parents;
-
- memcpy(bs_dest->op_blockers, bs_src->op_blockers,
- sizeof(bs_dest->op_blockers));
-}
-
-/*
- * Swap bs contents for two image chains while they are live,
- * while keeping required fields on the BlockDriverState that is
- * actually attached to a device.
- *
- * This will modify the BlockDriverState fields, and swap contents
- * between bs_new and bs_old. Both bs_new and bs_old are modified.
- *
- * bs_new must not be attached to a BlockBackend.
- *
- * This function does not create any image files.
- */
-void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
-{
- BlockDriverState tmp;
- BdrvChild *child;
-
- bdrv_drain(bs_new);
- bdrv_drain(bs_old);
-
- /* The code needs to swap the node_name but simply swapping node_list won't
- * work so first remove the nodes from the graph list, do the swap then
- * insert them back if needed.
- */
- if (bs_new->node_name[0] != '\0') {
- QTAILQ_REMOVE(&graph_bdrv_states, bs_new, node_list);
- }
- if (bs_old->node_name[0] != '\0') {
- QTAILQ_REMOVE(&graph_bdrv_states, bs_old, node_list);
- }
-
- /* If the BlockDriverState is part of a throttling group acquire
- * its lock since we're going to mess with the protected fields.
- * Otherwise there's no need to worry since no one else can touch
- * them. */
- if (bs_old->throttle_state) {
- throttle_group_lock(bs_old);
- }
-
- /* bs_new must be unattached and shouldn't have anything fancy enabled */
- assert(!bs_new->blk);
- assert(QLIST_EMPTY(&bs_new->dirty_bitmaps));
- assert(bs_new->job == NULL);
- assert(bs_new->io_limits_enabled == false);
- assert(bs_new->throttle_state == NULL);
- assert(!throttle_timers_are_initialized(&bs_new->throttle_timers));
-
- tmp = *bs_new;
- *bs_new = *bs_old;
- *bs_old = tmp;
-
- /* there are some fields that should not be swapped, move them back */
- bdrv_move_feature_fields(&tmp, bs_old);
- bdrv_move_feature_fields(bs_old, bs_new);
- bdrv_move_feature_fields(bs_new, &tmp);
-
- bdrv_move_reference_fields(&tmp, bs_old);
- bdrv_move_reference_fields(bs_old, bs_new);
- bdrv_move_reference_fields(bs_new, &tmp);
-
- /* bs_new must remain unattached */
- assert(!bs_new->blk);
-
- /* Check a few fields that should remain attached to the device */
- assert(bs_new->job == NULL);
- assert(bs_new->io_limits_enabled == false);
- assert(bs_new->throttle_state == NULL);
- assert(!throttle_timers_are_initialized(&bs_new->throttle_timers));
-
- /* Release the ThrottleGroup lock */
- if (bs_old->throttle_state) {
- throttle_group_unlock(bs_old);
- }
-
- /* insert the nodes back into the graph node list if needed */
- if (bs_new->node_name[0] != '\0') {
- QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_new, node_list);
- }
- if (bs_old->node_name[0] != '\0') {
- QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_old, node_list);
- }
-
- /*
- * Update lh_first.le_prev for non-empty lists.
- *
- * The head of the op blocker list doesn't change because it is moved back
- * in bdrv_move_feature_fields().
- */
- assert(QLIST_EMPTY(&bs_old->tracked_requests));
- assert(QLIST_EMPTY(&bs_new->tracked_requests));
-
- QLIST_FIX_HEAD_PTR(&bs_new->children, next);
- QLIST_FIX_HEAD_PTR(&bs_old->children, next);
-
- /* Update references in bs->opaque and children */
- QLIST_FOREACH(child, &bs_old->children, next) {
- if (child->bs->inherits_from == bs_new) {
- child->bs->inherits_from = bs_old;
- }
- }
- QLIST_FOREACH(child, &bs_new->children, next) {
- if (child->bs->inherits_from == bs_old) {
- child->bs->inherits_from = bs_new;
- }
- }
-
- bdrv_rebind(bs_new);
- bdrv_rebind(bs_old);
-}
-
static void change_parent_backing_link(BlockDriverState *from,
BlockDriverState *to)
{
bdrv_unref(bs_new);
}
+void bdrv_replace_in_backing_chain(BlockDriverState *old, BlockDriverState *new)
+{
+ assert(!bdrv_requests_pending(old));
+ assert(!bdrv_requests_pending(new));
+
+ bdrv_ref(old);
+
+ if (old->blk) {
+ /* As long as these fields aren't in BlockBackend, but in the top-level
+ * BlockDriverState, it's not possible for a BDS to have two BBs.
+ *
+ * We really want to copy the fields from old to new, but we go for a
+ * swap instead so that pointers aren't duplicated and cause trouble.
+ * (Also, bdrv_swap() used to do the same.) */
+ assert(!new->blk);
+ swap_feature_fields(old, new);
+ }
+ change_parent_backing_link(old, new);
+
+ /* Change backing files if a previously independent node is added to the
+ * chain. For active commit, we replace top by its own (indirect) backing
+ * file and don't do anything here so we don't build a loop. */
+ if (new->backing == NULL && !bdrv_chain_contains(backing_bs(old), new)) {
+ bdrv_set_backing_hd(new, backing_bs(old));
+ bdrv_set_backing_hd(old, NULL);
+ }
+
+ bdrv_unref(old);
+}
+
static void bdrv_delete(BlockDriverState *bs)
{
assert(!bs->job);
projects / qemu.git / blobdiff