qemu/blockjob.c
Markus Armbruster 84d18f065f Use error_is_set() only when necessary
error_is_set(&var) is the same as var != NULL, but it takes
whole-program analysis to figure that out.  Unnecessarily hard for
optimizers, static checkers, and human readers.  Dumb it down to
obvious.

Gets rid of several dozen Coverity false positives.

Note that the obvious form is already used in many places.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-02-17 11:57:23 -05:00

285 lines
7.6 KiB
C

/*
* QEMU System Emulator block driver
*
* Copyright (c) 2011 IBM Corp.
* Copyright (c) 2012 Red Hat, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "config-host.h"
#include "qemu-common.h"
#include "trace.h"
#include "monitor/monitor.h"
#include "block/block.h"
#include "block/blockjob.h"
#include "block/block_int.h"
#include "qapi/qmp/qjson.h"
#include "block/coroutine.h"
#include "qmp-commands.h"
#include "qemu/timer.h"
void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
int64_t speed, BlockDriverCompletionFunc *cb,
void *opaque, Error **errp)
{
BlockJob *job;
if (bs->job || bdrv_in_use(bs)) {
error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
return NULL;
}
bdrv_ref(bs);
bdrv_set_in_use(bs, 1);
job = g_malloc0(driver->instance_size);
job->driver = driver;
job->bs = bs;
job->cb = cb;
job->opaque = opaque;
job->busy = true;
bs->job = job;
/* Only set speed when necessary to avoid NotSupported error */
if (speed != 0) {
Error *local_err = NULL;
block_job_set_speed(job, speed, &local_err);
if (local_err) {
bs->job = NULL;
g_free(job);
bdrv_set_in_use(bs, 0);
error_propagate(errp, local_err);
return NULL;
}
}
return job;
}
void block_job_completed(BlockJob *job, int ret)
{
BlockDriverState *bs = job->bs;
assert(bs->job == job);
job->cb(job->opaque, ret);
bs->job = NULL;
g_free(job);
bdrv_set_in_use(bs, 0);
}
void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
{
Error *local_err = NULL;
if (!job->driver->set_speed) {
error_set(errp, QERR_NOT_SUPPORTED);
return;
}
job->driver->set_speed(job, speed, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
job->speed = speed;
}
void block_job_complete(BlockJob *job, Error **errp)
{
if (job->paused || job->cancelled || !job->driver->complete) {
error_set(errp, QERR_BLOCK_JOB_NOT_READY, job->bs->device_name);
return;
}
job->driver->complete(job, errp);
}
void block_job_pause(BlockJob *job)
{
job->paused = true;
}
bool block_job_is_paused(BlockJob *job)
{
return job->paused;
}
void block_job_resume(BlockJob *job)
{
job->paused = false;
block_job_iostatus_reset(job);
if (job->co && !job->busy) {
qemu_coroutine_enter(job->co, NULL);
}
}
void block_job_cancel(BlockJob *job)
{
job->cancelled = true;
block_job_resume(job);
}
bool block_job_is_cancelled(BlockJob *job)
{
return job->cancelled;
}
void block_job_iostatus_reset(BlockJob *job)
{
job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
if (job->driver->iostatus_reset) {
job->driver->iostatus_reset(job);
}
}
struct BlockCancelData {
BlockJob *job;
BlockDriverCompletionFunc *cb;
void *opaque;
bool cancelled;
int ret;
};
static void block_job_cancel_cb(void *opaque, int ret)
{
struct BlockCancelData *data = opaque;
data->cancelled = block_job_is_cancelled(data->job);
data->ret = ret;
data->cb(data->opaque, ret);
}
int block_job_cancel_sync(BlockJob *job)
{
struct BlockCancelData data;
BlockDriverState *bs = job->bs;
assert(bs->job == job);
/* Set up our own callback to store the result and chain to
* the original callback.
*/
data.job = job;
data.cb = job->cb;
data.opaque = job->opaque;
data.ret = -EINPROGRESS;
job->cb = block_job_cancel_cb;
job->opaque = &data;
block_job_cancel(job);
while (data.ret == -EINPROGRESS) {
qemu_aio_wait();
}
return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
}
void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns)
{
assert(job->busy);
/* Check cancellation *before* setting busy = false, too! */
if (block_job_is_cancelled(job)) {
return;
}
job->busy = false;
if (block_job_is_paused(job)) {
qemu_coroutine_yield();
} else {
co_sleep_ns(type, ns);
}
job->busy = true;
}
BlockJobInfo *block_job_query(BlockJob *job)
{
BlockJobInfo *info = g_new0(BlockJobInfo, 1);
info->type = g_strdup(BlockJobType_lookup[job->driver->job_type]);
info->device = g_strdup(bdrv_get_device_name(job->bs));
info->len = job->len;
info->busy = job->busy;
info->paused = job->paused;
info->offset = job->offset;
info->speed = job->speed;
info->io_status = job->iostatus;
return info;
}
static void block_job_iostatus_set_err(BlockJob *job, int error)
{
if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
BLOCK_DEVICE_IO_STATUS_FAILED;
}
}
QObject *qobject_from_block_job(BlockJob *job)
{
return qobject_from_jsonf("{ 'type': %s,"
"'device': %s,"
"'len': %" PRId64 ","
"'offset': %" PRId64 ","
"'speed': %" PRId64 " }",
BlockJobType_lookup[job->driver->job_type],
bdrv_get_device_name(job->bs),
job->len,
job->offset,
job->speed);
}
void block_job_ready(BlockJob *job)
{
QObject *data = qobject_from_block_job(job);
monitor_protocol_event(QEVENT_BLOCK_JOB_READY, data);
qobject_decref(data);
}
BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs,
BlockdevOnError on_err,
int is_read, int error)
{
BlockErrorAction action;
switch (on_err) {
case BLOCKDEV_ON_ERROR_ENOSPC:
action = (error == ENOSPC) ? BDRV_ACTION_STOP : BDRV_ACTION_REPORT;
break;
case BLOCKDEV_ON_ERROR_STOP:
action = BDRV_ACTION_STOP;
break;
case BLOCKDEV_ON_ERROR_REPORT:
action = BDRV_ACTION_REPORT;
break;
case BLOCKDEV_ON_ERROR_IGNORE:
action = BDRV_ACTION_IGNORE;
break;
default:
abort();
}
bdrv_emit_qmp_error_event(job->bs, QEVENT_BLOCK_JOB_ERROR, action, is_read);
if (action == BDRV_ACTION_STOP) {
block_job_pause(job);
block_job_iostatus_set_err(job, error);
if (bs != job->bs) {
bdrv_iostatus_set_err(bs, error);
}
}
return action;
}