Archipelago » qemu

/*

 * 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 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_ref(bs);

    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_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->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_complete(BlockJob *job, Error **errp)

{

    if (job->paused || job->cancelled || !job->job_type->complete) {

        error_set(errp, QERR_BLOCK_JOB_NOT_READY, job->bs->device_name);

        return;

    }

    job->job_type->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->job_type->iostatus_reset) {

        job->job_type->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(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;

    }

}

QObject *qobject_from_block_job(BlockJob *job)

{

    return qobject_from_jsonf("{ 'type': %s,"

                              "'device': %s,"

                              "'len': %" PRId64 ","

                              "'offset': %" PRId64 ","

                              "'speed': %" PRId64 " }",

                              job->job_type->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;

}