qemu/blockjob.c
Paolo Bonzini 32c81a4a6e block: introduce block job error
The following behaviors are possible:

'report': The behavior is the same as in 1.1.  An I/O error,
respectively during a read or a write, will complete the job immediately
with an error code.

'ignore': An I/O error, respectively during a read or a write, will be
ignored.  For streaming, the job will complete with an error and the
backing file will be left in place.  For mirroring, the sector will be
marked again as dirty and re-examined later.

'stop': The job will be paused and the job iostatus will be set to
failed or nospace, while the VM will keep running.  This can only be
specified if the block device has rerror=stop and werror=stop or enospc.

'enospc': Behaves as 'stop' for ENOSPC errors, 'report' for others.

In all cases, even for 'report', the I/O error is reported as a QMP
event BLOCK_JOB_ERROR, with the same arguments as BLOCK_IO_ERROR.

It is possible that while stopping the VM a BLOCK_IO_ERROR event will be
reported and will clobber the event from BLOCK_JOB_ERROR, or vice versa.
This is not really avoidable since stopping the VM completes all pending
I/O requests.  In fact, it is already possible now that a series of
BLOCK_IO_ERROR events are reported with rerror=stop, because vm_stop
calls bdrv_drain_all and this can generate further errors.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:40:56 +02:00

250 lines
6.5 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.h"
#include "block.h"
#include "blockjob.h"
#include "block_int.h"
#include "qjson.h"
#include "qemu-coroutine.h"
#include "qmp-commands.h"
#include "qemu-timer.h"
void *block_job_create(const BlockJobType *job_type, 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_set_in_use(bs, 1);
job = g_malloc0(job_type->instance_size);
job->job_type = job_type;
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 (error_is_set(&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_complete(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->job_type->set_speed) {
error_set(errp, QERR_NOT_SUPPORTED);
return;
}
job->job_type->set_speed(job, speed, &local_err);
if (error_is_set(&local_err)) {
error_propagate(errp, local_err);
return;
}
job->speed = speed;
}
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;
}
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, QEMUClock *clock, 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(clock, ns);
}
job->busy = true;
}
BlockJobInfo *block_job_query(BlockJob *job)
{
BlockJobInfo *info = g_new0(BlockJobInfo, 1);
info->type = g_strdup(job->job_type->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;
}
}
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;
}