return 0;
}
+static bool bdrv_child_cb_can_set_aio_ctx(BdrvChild *child, AioContext *ctx,
+ GSList **ignore, Error **errp)
+{
+ BlockDriverState *bs = child->opaque;
+ return bdrv_can_set_aio_context(bs, ctx, ignore, errp);
+}
+
+static void bdrv_child_cb_set_aio_ctx(BdrvChild *child, AioContext *ctx,
+ GSList **ignore)
+{
+ BlockDriverState *bs = child->opaque;
+ return bdrv_set_aio_context_ignore(bs, ctx, ignore);
+}
+
/*
* Returns the options and flags that a temporary snapshot should get, based on
* the originally requested flags (the originally requested image will have
qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on");
- /* Copy the read-only option from the parent */
+ /* Copy the read-only and discard options from the parent */
qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
+ qdict_copy_default(child_options, parent_options, BDRV_OPT_DISCARD);
/* aio=native doesn't work for cache.direct=off, so disable it for the
* temporary snapshot */
.attach = bdrv_child_cb_attach,
.detach = bdrv_child_cb_detach,
.inactivate = bdrv_child_cb_inactivate,
+ .can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx,
+ .set_aio_ctx = bdrv_child_cb_set_aio_ctx,
};
/*
.attach = bdrv_child_cb_attach,
.detach = bdrv_child_cb_detach,
.inactivate = bdrv_child_cb_inactivate,
+ .can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx,
+ .set_aio_ctx = bdrv_child_cb_set_aio_ctx,
};
static void bdrv_backing_attach(BdrvChild *c)
.drained_end = bdrv_child_cb_drained_end,
.inactivate = bdrv_child_cb_inactivate,
.update_filename = bdrv_backing_update_filename,
+ .can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx,
+ .set_aio_ctx = bdrv_child_cb_set_aio_ctx,
};
static int bdrv_open_flags(BlockDriverState *bs, int flags)
GSList *ignore_children, Error **errp);
static void bdrv_child_abort_perm_update(BdrvChild *c);
static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared);
+static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
+ uint64_t *shared_perm);
typedef struct BlockReopenQueueEntry {
bool prepared;
uint64_t parent_perm, uint64_t parent_shared,
uint64_t *nperm, uint64_t *nshared)
{
- if (bs->drv && bs->drv->bdrv_child_perm) {
- bs->drv->bdrv_child_perm(bs, c, role, reopen_queue,
- parent_perm, parent_shared,
- nperm, nshared);
- }
+ assert(bs->drv && bs->drv->bdrv_child_perm);
+ bs->drv->bdrv_child_perm(bs, c, role, reopen_queue,
+ parent_perm, parent_shared,
+ nperm, nshared);
/* TODO Take force_share from reopen_queue */
if (child_bs && child_bs->force_share) {
*nshared = BLK_PERM_ALL;
if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) &&
!bdrv_is_writable_after_reopen(bs, q))
{
- error_setg(errp, "Block node is read-only");
+ if (!bdrv_is_writable_after_reopen(bs, NULL)) {
+ error_setg(errp, "Block node is read-only");
+ } else {
+ uint64_t current_perms, current_shared;
+ bdrv_get_cumulative_perm(bs, ¤t_perms, ¤t_shared);
+ if (current_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) {
+ error_setg(errp, "Cannot make block node read-only, there is "
+ "a writer on it");
+ } else {
+ error_setg(errp, "Cannot make block node read-only and create "
+ "a writer on it");
+ }
+ }
+
return -EPERM;
}
assert(bdrv_op_blocker_is_empty(bs));
assert(!bs->refcnt);
- bdrv_close(bs);
-
/* remove from list, if necessary */
if (bs->node_name[0] != '\0') {
QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
}
QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list);
+ bdrv_close(bs);
+
g_free(bs);
}
int ret;
} CheckCo;
-static void bdrv_check_co_entry(void *opaque)
+static void coroutine_fn bdrv_check_co_entry(void *opaque)
{
CheckCo *cco = opaque;
cco->ret = bdrv_co_check(cco->bs, cco->res, cco->fix);
/*
* Return true if at least one of the backing links between @bs and
* @base is frozen. @errp is set if that's the case.
+ * @base must be reachable from @bs, or NULL.
*/
bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
Error **errp)
{
BlockDriverState *i;
- for (i = bs; i != base && i->backing; i = backing_bs(i)) {
- if (i->backing->frozen) {
+ for (i = bs; i != base; i = backing_bs(i)) {
+ if (i->backing && i->backing->frozen) {
error_setg(errp, "Cannot change '%s' link from '%s' to '%s'",
i->backing->name, i->node_name,
backing_bs(i)->node_name);
* Freeze all backing links between @bs and @base.
* If any of the links is already frozen the operation is aborted and
* none of the links are modified.
+ * @base must be reachable from @bs, or NULL.
* Returns 0 on success. On failure returns < 0 and sets @errp.
*/
int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
return -EPERM;
}
- for (i = bs; i != base && i->backing; i = backing_bs(i)) {
- i->backing->frozen = true;
+ for (i = bs; i != base; i = backing_bs(i)) {
+ if (i->backing) {
+ i->backing->frozen = true;
+ }
}
return 0;
/*
* Unfreeze all backing links between @bs and @base. The caller must
* ensure that all links are frozen before using this function.
+ * @base must be reachable from @bs, or NULL.
*/
void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base)
{
BlockDriverState *i;
- for (i = bs; i != base && i->backing; i = backing_bs(i)) {
- assert(i->backing->frozen);
- i->backing->frozen = false;
+ for (i = bs; i != base; i = backing_bs(i)) {
+ if (i->backing) {
+ assert(i->backing->frozen);
+ i->backing->frozen = false;
+ }
}
}
QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
/* Check whether we are allowed to switch c from top to base */
GSList *ignore_children = g_slist_prepend(NULL, c);
- bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
- ignore_children, &local_err);
+ ret = bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
+ ignore_children, &local_err);
g_slist_free(ignore_children);
- if (local_err) {
- ret = -EPERM;
+ if (ret < 0) {
error_report_err(local_err);
goto exit;
}
g_free(ban);
}
-void bdrv_detach_aio_context(BlockDriverState *bs)
+static void bdrv_detach_aio_context(BlockDriverState *bs)
{
BdrvAioNotifier *baf, *baf_tmp;
- BdrvChild *child;
-
- if (!bs->drv) {
- return;
- }
assert(!bs->walking_aio_notifiers);
bs->walking_aio_notifiers = true;
*/
bs->walking_aio_notifiers = false;
- if (bs->drv->bdrv_detach_aio_context) {
+ if (bs->drv && bs->drv->bdrv_detach_aio_context) {
bs->drv->bdrv_detach_aio_context(bs);
}
- QLIST_FOREACH(child, &bs->children, next) {
- bdrv_detach_aio_context(child->bs);
- }
if (bs->quiesce_counter) {
aio_enable_external(bs->aio_context);
bs->aio_context = NULL;
}
-void bdrv_attach_aio_context(BlockDriverState *bs,
- AioContext *new_context)
+static void bdrv_attach_aio_context(BlockDriverState *bs,
+ AioContext *new_context)
{
BdrvAioNotifier *ban, *ban_tmp;
- BdrvChild *child;
-
- if (!bs->drv) {
- return;
- }
if (bs->quiesce_counter) {
aio_disable_external(new_context);
bs->aio_context = new_context;
- QLIST_FOREACH(child, &bs->children, next) {
- bdrv_attach_aio_context(child->bs, new_context);
- }
- if (bs->drv->bdrv_attach_aio_context) {
+ if (bs->drv && bs->drv->bdrv_attach_aio_context) {
bs->drv->bdrv_attach_aio_context(bs, new_context);
}
bs->walking_aio_notifiers = false;
}
-/* The caller must own the AioContext lock for the old AioContext of bs, but it
- * must not own the AioContext lock for new_context (unless new_context is
- * the same as the current context of bs). */
-void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
+/* @ignore will accumulate all visited BdrvChild object. The caller is
+ * responsible for freeing the list afterwards. */
+void bdrv_set_aio_context_ignore(BlockDriverState *bs,
+ AioContext *new_context, GSList **ignore)
{
+ BdrvChild *child;
+
if (bdrv_get_aio_context(bs) == new_context) {
return;
}
bdrv_drained_begin(bs);
+
+ QLIST_FOREACH(child, &bs->children, next) {
+ if (g_slist_find(*ignore, child)) {
+ continue;
+ }
+ *ignore = g_slist_prepend(*ignore, child);
+ bdrv_set_aio_context_ignore(child->bs, new_context, ignore);
+ }
+ QLIST_FOREACH(child, &bs->parents, next_parent) {
+ if (g_slist_find(*ignore, child)) {
+ continue;
+ }
+ if (child->role->set_aio_ctx) {
+ *ignore = g_slist_prepend(*ignore, child);
+ child->role->set_aio_ctx(child, new_context, ignore);
+ }
+ }
+
bdrv_detach_aio_context(bs);
/* This function executes in the old AioContext so acquire the new one in
aio_context_release(new_context);
}
+/* The caller must own the AioContext lock for the old AioContext of bs, but it
+ * must not own the AioContext lock for new_context (unless new_context is
+ * the same as the current context of bs). */
+void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
+{
+ GSList *ignore_list = NULL;
+ bdrv_set_aio_context_ignore(bs, new_context, &ignore_list);
+ g_slist_free(ignore_list);
+}
+
+static bool bdrv_parent_can_set_aio_context(BdrvChild *c, AioContext *ctx,
+ GSList **ignore, Error **errp)
+{
+ if (g_slist_find(*ignore, c)) {
+ return true;
+ }
+ *ignore = g_slist_prepend(*ignore, c);
+
+ /* A BdrvChildRole that doesn't handle AioContext changes cannot
+ * tolerate any AioContext changes */
+ if (!c->role->can_set_aio_ctx) {
+ char *user = bdrv_child_user_desc(c);
+ error_setg(errp, "Changing iothreads is not supported by %s", user);
+ g_free(user);
+ return false;
+ }
+ if (!c->role->can_set_aio_ctx(c, ctx, ignore, errp)) {
+ assert(!errp || *errp);
+ return false;
+ }
+ return true;
+}
+
+bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx,
+ GSList **ignore, Error **errp)
+{
+ if (g_slist_find(*ignore, c)) {
+ return true;
+ }
+ *ignore = g_slist_prepend(*ignore, c);
+ return bdrv_can_set_aio_context(c->bs, ctx, ignore, errp);
+}
+
+/* @ignore will accumulate all visited BdrvChild object. The caller is
+ * responsible for freeing the list afterwards. */
+bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx,
+ GSList **ignore, Error **errp)
+{
+ BdrvChild *c;
+
+ if (bdrv_get_aio_context(bs) == ctx) {
+ return true;
+ }
+
+ QLIST_FOREACH(c, &bs->parents, next_parent) {
+ if (!bdrv_parent_can_set_aio_context(c, ctx, ignore, errp)) {
+ return false;
+ }
+ }
+ QLIST_FOREACH(c, &bs->children, next) {
+ if (!bdrv_child_can_set_aio_context(c, ctx, ignore, errp)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
+ BdrvChild *ignore_child, Error **errp)
+{
+ GSList *ignore;
+ bool ret;
+
+ ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL;
+ ret = bdrv_can_set_aio_context(bs, ctx, &ignore, errp);
+ g_slist_free(ignore);
+
+ if (!ret) {
+ return -EPERM;
+ }
+
+ ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL;
+ bdrv_set_aio_context_ignore(bs, ctx, &ignore);
+ g_slist_free(ignore);
+
+ return 0;
+}
+
+int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
+ Error **errp)
+{
+ return bdrv_child_try_set_aio_context(bs, ctx, NULL, errp);
+}
+
void bdrv_add_aio_context_notifier(BlockDriverState *bs,
void (*attached_aio_context)(AioContext *new_context, void *opaque),
void (*detach_aio_context)(void *opaque), void *opaque)
projects / qemu.git / blobdiff