mirror of
https://gitlab.com/qemu-project/qemu
synced 2024-09-06 18:05:37 +00:00
![Fam Zheng](/assets/img/avatar_default.png)
This patch changes block_job_pause to increase the pause counter and block_job_resume to decrease it. The counter will allow calling block_job_pause/block_job_resume unconditionally on a job when we need to suspend the IO temporarily. From now on, each block_job_resume must be paired with a block_job_pause to keep the counter balanced. The user pause from QMP or HMP will only trigger block_job_pause once until it's resumed, this is achieved by adding a user_paused flag in BlockJob. One occurrence of block_job_resume in mirror_complete is replaced with block_job_enter which does what is necessary. In block_job_cancel, the cancel flag is good enough to instruct coroutines to quit loop, so use block_job_enter to replace the unpaired block_job_resume. Upon block job IO error, user is notified about the entering to the pause state, so this pause belongs to user pause, set the flag accordingly and expect a matching QMP resume. [Extended doc comments as suggested by Paolo Bonzini <pbonzini@redhat.com>. --Stefan] Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 1428069921-2957-2-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
402 lines
11 KiB
C
402 lines
11 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 "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"
|
|
#include "qapi-event.h"
|
|
|
|
void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
|
|
int64_t speed, BlockCompletionFunc *cb,
|
|
void *opaque, Error **errp)
|
|
{
|
|
BlockJob *job;
|
|
|
|
if (bs->job) {
|
|
error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
|
|
return NULL;
|
|
}
|
|
bdrv_ref(bs);
|
|
job = g_malloc0(driver->instance_size);
|
|
error_setg(&job->blocker, "block device is in use by block job: %s",
|
|
BlockJobType_lookup[driver->job_type]);
|
|
bdrv_op_block_all(bs, job->blocker);
|
|
bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
|
|
|
|
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;
|
|
bdrv_op_unblock_all(bs, job->blocker);
|
|
error_free(job->blocker);
|
|
g_free(job);
|
|
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;
|
|
bdrv_op_unblock_all(bs, job->blocker);
|
|
error_free(job->blocker);
|
|
g_free(job);
|
|
}
|
|
|
|
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_UNSUPPORTED);
|
|
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->pause_count || job->cancelled || !job->driver->complete) {
|
|
error_set(errp, QERR_BLOCK_JOB_NOT_READY,
|
|
bdrv_get_device_name(job->bs));
|
|
return;
|
|
}
|
|
|
|
job->driver->complete(job, errp);
|
|
}
|
|
|
|
void block_job_pause(BlockJob *job)
|
|
{
|
|
job->pause_count++;
|
|
}
|
|
|
|
bool block_job_is_paused(BlockJob *job)
|
|
{
|
|
return job->pause_count > 0;
|
|
}
|
|
|
|
void block_job_resume(BlockJob *job)
|
|
{
|
|
assert(job->pause_count > 0);
|
|
job->pause_count--;
|
|
if (job->pause_count) {
|
|
return;
|
|
}
|
|
block_job_enter(job);
|
|
}
|
|
|
|
void block_job_enter(BlockJob *job)
|
|
{
|
|
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_enter(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 BlockFinishData {
|
|
BlockJob *job;
|
|
BlockCompletionFunc *cb;
|
|
void *opaque;
|
|
bool cancelled;
|
|
int ret;
|
|
};
|
|
|
|
static void block_job_finish_cb(void *opaque, int ret)
|
|
{
|
|
struct BlockFinishData *data = opaque;
|
|
|
|
data->cancelled = block_job_is_cancelled(data->job);
|
|
data->ret = ret;
|
|
data->cb(data->opaque, ret);
|
|
}
|
|
|
|
static int block_job_finish_sync(BlockJob *job,
|
|
void (*finish)(BlockJob *, Error **errp),
|
|
Error **errp)
|
|
{
|
|
struct BlockFinishData data;
|
|
BlockDriverState *bs = job->bs;
|
|
Error *local_err = NULL;
|
|
|
|
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_finish_cb;
|
|
job->opaque = &data;
|
|
finish(job, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EBUSY;
|
|
}
|
|
while (data.ret == -EINPROGRESS) {
|
|
aio_poll(bdrv_get_aio_context(bs), true);
|
|
}
|
|
return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
|
|
}
|
|
|
|
/* A wrapper around block_job_cancel() taking an Error ** parameter so it may be
|
|
* used with block_job_finish_sync() without the need for (rather nasty)
|
|
* function pointer casts there. */
|
|
static void block_job_cancel_err(BlockJob *job, Error **errp)
|
|
{
|
|
block_job_cancel(job);
|
|
}
|
|
|
|
int block_job_cancel_sync(BlockJob *job)
|
|
{
|
|
return block_job_finish_sync(job, &block_job_cancel_err, NULL);
|
|
}
|
|
|
|
int block_job_complete_sync(BlockJob *job, Error **errp)
|
|
{
|
|
return block_job_finish_sync(job, &block_job_complete, errp);
|
|
}
|
|
|
|
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_aio_sleep_ns(bdrv_get_aio_context(job->bs), type, ns);
|
|
}
|
|
job->busy = true;
|
|
}
|
|
|
|
void block_job_yield(BlockJob *job)
|
|
{
|
|
assert(job->busy);
|
|
|
|
/* Check cancellation *before* setting busy = false, too! */
|
|
if (block_job_is_cancelled(job)) {
|
|
return;
|
|
}
|
|
|
|
job->busy = false;
|
|
qemu_coroutine_yield();
|
|
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->pause_count > 0;
|
|
info->offset = job->offset;
|
|
info->speed = job->speed;
|
|
info->io_status = job->iostatus;
|
|
info->ready = job->ready;
|
|
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;
|
|
}
|
|
}
|
|
|
|
void block_job_event_cancelled(BlockJob *job)
|
|
{
|
|
qapi_event_send_block_job_cancelled(job->driver->job_type,
|
|
bdrv_get_device_name(job->bs),
|
|
job->len,
|
|
job->offset,
|
|
job->speed,
|
|
&error_abort);
|
|
}
|
|
|
|
void block_job_event_completed(BlockJob *job, const char *msg)
|
|
{
|
|
qapi_event_send_block_job_completed(job->driver->job_type,
|
|
bdrv_get_device_name(job->bs),
|
|
job->len,
|
|
job->offset,
|
|
job->speed,
|
|
!!msg,
|
|
msg,
|
|
&error_abort);
|
|
}
|
|
|
|
void block_job_event_ready(BlockJob *job)
|
|
{
|
|
job->ready = true;
|
|
|
|
qapi_event_send_block_job_ready(job->driver->job_type,
|
|
bdrv_get_device_name(job->bs),
|
|
job->len,
|
|
job->offset,
|
|
job->speed, &error_abort);
|
|
}
|
|
|
|
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) ?
|
|
BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
|
|
break;
|
|
case BLOCKDEV_ON_ERROR_STOP:
|
|
action = BLOCK_ERROR_ACTION_STOP;
|
|
break;
|
|
case BLOCKDEV_ON_ERROR_REPORT:
|
|
action = BLOCK_ERROR_ACTION_REPORT;
|
|
break;
|
|
case BLOCKDEV_ON_ERROR_IGNORE:
|
|
action = BLOCK_ERROR_ACTION_IGNORE;
|
|
break;
|
|
default:
|
|
abort();
|
|
}
|
|
qapi_event_send_block_job_error(bdrv_get_device_name(job->bs),
|
|
is_read ? IO_OPERATION_TYPE_READ :
|
|
IO_OPERATION_TYPE_WRITE,
|
|
action, &error_abort);
|
|
if (action == BLOCK_ERROR_ACTION_STOP) {
|
|
/* make the pause user visible, which will be resumed from QMP. */
|
|
job->user_paused = true;
|
|
block_job_pause(job);
|
|
block_job_iostatus_set_err(job, error);
|
|
if (bs != job->bs) {
|
|
bdrv_iostatus_set_err(bs, error);
|
|
}
|
|
}
|
|
return action;
|
|
}
|
|
|
|
typedef struct {
|
|
BlockJob *job;
|
|
QEMUBH *bh;
|
|
AioContext *aio_context;
|
|
BlockJobDeferToMainLoopFn *fn;
|
|
void *opaque;
|
|
} BlockJobDeferToMainLoopData;
|
|
|
|
static void block_job_defer_to_main_loop_bh(void *opaque)
|
|
{
|
|
BlockJobDeferToMainLoopData *data = opaque;
|
|
AioContext *aio_context;
|
|
|
|
qemu_bh_delete(data->bh);
|
|
|
|
/* Prevent race with block_job_defer_to_main_loop() */
|
|
aio_context_acquire(data->aio_context);
|
|
|
|
/* Fetch BDS AioContext again, in case it has changed */
|
|
aio_context = bdrv_get_aio_context(data->job->bs);
|
|
aio_context_acquire(aio_context);
|
|
|
|
data->fn(data->job, data->opaque);
|
|
|
|
aio_context_release(aio_context);
|
|
|
|
aio_context_release(data->aio_context);
|
|
|
|
g_free(data);
|
|
}
|
|
|
|
void block_job_defer_to_main_loop(BlockJob *job,
|
|
BlockJobDeferToMainLoopFn *fn,
|
|
void *opaque)
|
|
{
|
|
BlockJobDeferToMainLoopData *data = g_malloc(sizeof(*data));
|
|
data->job = job;
|
|
data->bh = qemu_bh_new(block_job_defer_to_main_loop_bh, data);
|
|
data->aio_context = bdrv_get_aio_context(job->bs);
|
|
data->fn = fn;
|
|
data->opaque = opaque;
|
|
|
|
qemu_bh_schedule(data->bh);
|
|
}
|