From include/qapi/error.h:
* Pass an existing error to the caller with the message modified:
* error_propagate(errp, err);
* error_prepend(errp, "Could not frobnicate '%s': ", name);
Fei Li pointed out that doing error_propagate() first doesn't work
well when @errp is &error_fatal or &error_abort: the error_prepend()
is never reached.
Since I doubt fixing the documentation will stop people from getting
it wrong, introduce error_propagate_prepend(), in the hope that it
lures people away from using its constituents in the wrong order.
Update the instructions in error.h accordingly.
Convert existing error_prepend() next to error_propagate to
error_propagate_prepend(). If any of these get reached with
&error_fatal or &error_abort, the error messages improve. I didn't
check whether that's the case anywhere.
Cc: Fei Li <fli@suse.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <
20181017082702.5581-2-armbru@redhat.com>
assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
if (!QLIST_EMPTY(&bs->op_blockers[op])) {
blocker = QLIST_FIRST(&bs->op_blockers[op]);
- error_propagate(errp, error_copy(blocker->reason));
- error_prepend(errp, "Node '%s' is busy: ",
- bdrv_get_device_or_node_name(bs));
+ error_propagate_prepend(errp, error_copy(blocker->reason),
+ "Node '%s' is busy: ",
+ bdrv_get_device_or_node_name(bs));
return true;
}
return false;
qemu_co_mutex_unlock(&s->lock);
qobject_unref(options);
if (local_err) {
- error_propagate(errp, local_err);
- error_prepend(errp, "Could not reopen qcow2 layer: ");
+ error_propagate_prepend(errp, local_err,
+ "Could not reopen qcow2 layer: ");
bs->drv = NULL;
return;
} else if (ret < 0) {
ret = bdrv_qed_do_open(bs, NULL, bs->open_flags, &local_err);
qemu_co_mutex_unlock(&s->table_lock);
if (local_err) {
- error_propagate(errp, local_err);
- error_prepend(errp, "Could not reopen qed layer: ");
+ error_propagate_prepend(errp, local_err,
+ "Could not reopen qed layer: ");
return;
} else if (ret < 0) {
error_setg_errno(errp, -ret, "Could not reopen qed layer");
fsdev_throttle_parse_opts(opts, &fse->fst, &local_err);
if (local_err) {
- error_propagate(errp, local_err);
- error_prepend(errp, "invalid throttle configuration: ");
+ error_propagate_prepend(errp, local_err,
+ "invalid throttle configuration: ");
return -1;
}
obj = object_property_get_link(OBJECT(dev), ICP_PROP_XICS, &err);
if (!obj) {
- error_propagate(errp, err);
- error_prepend(errp, "required link '" ICP_PROP_XICS "' not found: ");
+ error_propagate_prepend(errp, err,
+ "required link '" ICP_PROP_XICS
+ "' not found: ");
return;
}
obj = object_property_get_link(OBJECT(dev), ICP_PROP_CPU, &err);
if (!obj) {
- error_propagate(errp, err);
- error_prepend(errp, "required link '" ICP_PROP_CPU "' not found: ");
+ error_propagate_prepend(errp, err,
+ "required link '" ICP_PROP_CPU
+ "' not found: ");
return;
}
obj = object_property_get_link(OBJECT(dev), ICS_PROP_XICS, &err);
if (!obj) {
- error_propagate(errp, err);
- error_prepend(errp, "required link '" ICS_PROP_XICS "' not found: ");
+ error_propagate_prepend(errp, err,
+ "required link '" ICS_PROP_XICS
+ "' not found: ");
return;
}
ics->xics = XICS_FABRIC(obj);
chip = object_property_get_link(OBJECT(dev), "chip", &local_err);
if (!chip) {
- error_propagate(errp, local_err);
- error_prepend(errp, "required link 'chip' not found: ");
+ error_propagate_prepend(errp, local_err,
+ "required link 'chip' not found: ");
return;
}
if (smc->legacy_irq_allocation) {
irq = spapr_irq_findone(spapr, &local_err);
if (local_err) {
- error_propagate(errp, local_err);
- error_prepend(errp, "can't allocate LSIs: ");
+ error_propagate_prepend(errp, local_err,
+ "can't allocate LSIs: ");
return;
}
}
spapr_irq_claim(spapr, irq, true, &local_err);
if (local_err) {
- error_propagate(errp, local_err);
- error_prepend(errp, "can't allocate LSIs: ");
+ error_propagate_prepend(errp, local_err, "can't allocate LSIs: ");
return;
}
obj = object_property_get_link(OBJECT(dev), "scu", &err);
if (!obj) {
- error_propagate(errp, err);
- error_prepend(errp, "required link 'scu' not found: ");
+ error_propagate_prepend(errp, err, "required link 'scu' not found: ");
return;
}
s->scu = ASPEED_SCU(obj);
}
object_property_set_bool(OBJECT(dev), true, "realized", &err);
if (err) {
- error_propagate(errp, err);
- error_prepend(errp, "Failed to initialize USB device '%s': ", name);
+ error_propagate_prepend(errp, err,
+ "Failed to initialize USB device '%s': ",
+ name);
return NULL;
}
return dev;
if (ret == -ENOTSUP) {
return 0;
}
- error_prepend(&err, "msi_init failed: ");
- error_propagate(errp, err);
+ error_propagate_prepend(errp, err, "msi_init failed: ");
return ret;
}
vdev->msi_cap_size = 0xa + (msi_maskbit ? 0xa : 0) + (msi_64bit ? 0x4 : 0);
* where Error **errp is a parameter, by convention the last one.
*
* Pass an existing error to the caller with the message modified:
+ * error_propagate_prepend(errp, err);
+ *
+ * Avoid
* error_propagate(errp, err);
* error_prepend(errp, "Could not frobnicate '%s': ", name);
+ * because this fails to prepend when @errp is &error_fatal.
*
* Create a new error and pass it to the caller:
* error_setg(errp, "situation normal, all fouled up");
*/
void error_propagate(Error **dst_errp, Error *local_err);
+
+/*
+ * Propagate error object (if any) with some text prepended.
+ * Behaves like
+ * error_prepend(&local_err, fmt, ...);
+ * error_propagate(dst_errp, local_err);
+ */
+void error_propagate_prepend(Error **dst_errp, Error *local_err,
+ const char *fmt, ...);
+
/*
* Prepend some text to @errp's human-readable error message.
* The text is made by formatting @fmt, @ap like vprintf().
int migrate_add_blocker(Error *reason, Error **errp)
{
if (migrate_get_current()->only_migratable) {
- error_propagate(errp, error_copy(reason));
- error_prepend(errp, "disallowing migration blocker "
- "(--only_migratable) for: ");
+ error_propagate_prepend(errp, error_copy(reason),
+ "disallowing migration blocker "
+ "(--only_migratable) for: ");
return -EACCES;
}
return 0;
}
- error_propagate(errp, error_copy(reason));
- error_prepend(errp, "disallowing migration blocker (migration in "
- "progress) for: ");
+ error_propagate_prepend(errp, error_copy(reason),
+ "disallowing migration blocker "
+ "(migration in progress) for: ");
return -EBUSY;
}
error_free(local_err);
}
}
+
+void error_propagate_prepend(Error **dst_errp, Error *err,
+ const char *fmt, ...)
+{
+ va_list ap;
+
+ if (dst_errp && !*dst_errp) {
+ va_start(ap, fmt);
+ error_vprepend(&err, fmt, ap);
+ va_end(ap);
+ } /* else error is being ignored, don't bother with prepending */
+ error_propagate(dst_errp, err);
+}