@@ -346,10 +346,10 @@ int bdrv_create(BlockDriver *drv, const char* filename,
int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
BlockDriverState *bdrv_new(void);
-void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
- Error **errp);
-void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
- Error **errp);
+int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
+ Error **errp);
+int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
+ Error **errp);
int bdrv_parse_aio(const char *mode, int *flags);
int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
@@ -361,8 +361,8 @@ BdrvChild *bdrv_open_child(const char *filename,
BdrvChildRole child_role,
bool allow_none, Error **errp);
BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
-void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
- Error **errp);
+int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
+ Error **errp);
int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
const char *bdref_key, Error **errp);
BlockDriverState *bdrv_open(const char *filename, const char *reference,
@@ -2870,14 +2870,15 @@ static BdrvChildRole bdrv_backing_role(BlockDriverState *bs)
* Sets the bs->backing link of a BDS. A new reference is created; callers
* which don't need their own reference any more must call bdrv_unref().
*/
-void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
+int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
Error **errp)
{
+ int ret;
bool update_inherits_from = bdrv_chain_contains(bs, backing_hd) &&
bdrv_inherits_from_recursive(backing_hd, bs);
if (bdrv_is_backing_chain_frozen(bs, child_bs(bs->backing), errp)) {
- return;
+ return -EPERM;
}
if (backing_hd) {
@@ -2896,15 +2897,24 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_of_bds,
bdrv_backing_role(bs), errp);
+ if (!bs->backing) {
+ ret = -EPERM;
+ goto out;
+ }
+
/* If backing_hd was already part of bs's backing chain, and
* inherits_from pointed recursively to bs then let's update it to
* point directly to bs (else it will become NULL). */
- if (bs->backing && update_inherits_from) {
+ if (update_inherits_from) {
backing_hd->inherits_from = bs;
}
+ ret = 0;
+
out:
bdrv_refresh_limits(bs, NULL);
+
+ return ret;
}
/*
@@ -4554,8 +4564,8 @@ static bool should_update_child(BdrvChild *c, BlockDriverState *to)
return ret;
}
-void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
- Error **errp)
+int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
+ Error **errp)
{
BdrvChild *c, *next;
GSList *list = NULL, *p;
@@ -4577,6 +4587,7 @@ void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
continue;
}
if (c->frozen) {
+ ret = -EPERM;
error_setg(errp, "Cannot change '%s' link to '%s'",
c->name, from->node_name);
goto out;
@@ -4608,10 +4619,14 @@ void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
bdrv_get_cumulative_perm(to, &perm, &shared);
bdrv_set_perm(to, perm, shared);
+ ret = 0;
+
out:
g_slist_free(list);
bdrv_drained_end(from);
bdrv_unref(from);
+
+ return ret;
}
/*
@@ -4630,28 +4645,30 @@ out:
* parents of bs_top after bdrv_append() returns. If the caller needs to keep a
* reference of its own, it must call bdrv_ref().
*/
-void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
- Error **errp)
+int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
+ Error **errp)
{
- Error *local_err = NULL;
-
- bdrv_set_backing_hd(bs_new, bs_top, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
+ int ret = bdrv_set_backing_hd(bs_new, bs_top, errp);
+ if (ret < 0) {
goto out;
}
- bdrv_replace_node(bs_top, bs_new, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
+ ret = bdrv_replace_node(bs_top, bs_new, errp);
+ if (ret < 0) {
bdrv_set_backing_hd(bs_new, NULL, &error_abort);
goto out;
}
- /* bs_new is now referenced by its new parents, we don't need the
- * additional reference any more. */
+ ret = 0;
+
out:
+ /*
+ * bs_new is now referenced by its new parents, we don't need the
+ * additional reference any more.
+ */
bdrv_unref(bs_new);
+
+ return ret;
}
static void bdrv_delete(BlockDriverState *bs)
The recommended use of qemu error api assumes returning status together with setting errp and avoid void functions with errp parameter. Let's improve bdrv_append and some friends to reduce error-propagation overhead in further patches. Choose int return status, because bdrv_replace_node() has call to bdrv_check_update_perm(), which reports int status, which seems correct to propagate. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- include/block/block.h | 12 +++++----- block.c | 51 ++++++++++++++++++++++++++++--------------- 2 files changed, 40 insertions(+), 23 deletions(-)