blockjob.c - qemu - Git at Google

 /*
  * 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 "qemu/osdep.h"
 #include "block/block.h"
 #include "block/blockjob_int.h"
 #include "block/block_int.h"
 #include "block/trace.h"
 #include "sysemu/block-backend.h"
 #include "qapi/error.h"
 #include "qapi/qapi-events-block-core.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/coroutine.h"
 #include "qemu/main-loop.h"
 #include "qemu/timer.h"

 /*
  * The block job API is composed of two categories of functions.
  *
  * The first includes functions used by the monitor.  The monitor is
  * peculiar in that it accesses the block job list with block_job_get, and
  * therefore needs consistency across block_job_get and the actual operation
  * (e.g. block_job_set_speed).  The consistency is achieved with
  * aio_context_acquire/release.  These functions are declared in blockjob.h.
  *
  * The second includes functions used by the block job drivers and sometimes
  * by the core block layer.  These do not care about locking, because the
  * whole coroutine runs under the AioContext lock, and are declared in
  * blockjob_int.h.
  */

 static bool is_block_job(Job *job)
 {
     return job_type(job) == JOB_TYPE_BACKUP ||
            job_type(job) == JOB_TYPE_COMMIT ||
            job_type(job) == JOB_TYPE_MIRROR ||
            job_type(job) == JOB_TYPE_STREAM;
 }

 BlockJob *block_job_next(BlockJob *bjob)
 {
     Job *job = bjob ? &bjob->job : NULL;

     do {
         job = job_next(job);
     } while (job && !is_block_job(job));

     return job ? container_of(job, BlockJob, job) : NULL;
 }

 BlockJob *block_job_get(const char *id)
 {
     Job *job = job_get(id);

     if (job && is_block_job(job)) {
         return container_of(job, BlockJob, job);
     } else {
         return NULL;
     }
 }

 void block_job_free(Job *job)
 {
     BlockJob *bjob = container_of(job, BlockJob, job);

     block_job_remove_all_bdrv(bjob);
     blk_unref(bjob->blk);
     error_free(bjob->blocker);
 }

 void block_job_drain(Job *job)
 {
     BlockJob *bjob = container_of(job, BlockJob, job);
     const JobDriver *drv = job->driver;
     BlockJobDriver *bjdrv = container_of(drv, BlockJobDriver, job_driver);

     blk_drain(bjob->blk);
     if (bjdrv->drain) {
         bjdrv->drain(bjob);
     }
 }

 static char *child_job_get_parent_desc(BdrvChild *c)
 {
     BlockJob *job = c->opaque;
     return g_strdup_printf("%s job '%s'", job_type_str(&job->job), job->job.id);
 }

 static void child_job_drained_begin(BdrvChild *c)
 {
     BlockJob *job = c->opaque;
     job_pause(&job->job);
 }

 static bool child_job_drained_poll(BdrvChild *c)
 {
     BlockJob *bjob = c->opaque;
     Job *job = &bjob->job;
     const BlockJobDriver *drv = block_job_driver(bjob);

     /* An inactive or completed job doesn't have any pending requests. Jobs
      * with !job->busy are either already paused or have a pause point after
      * being reentered, so no job driver code will run before they pause. */
     if (!job->busy || job_is_completed(job)) {
         return false;
     }

     /* Otherwise, assume that it isn't fully stopped yet, but allow the job to
      * override this assumption. */
     if (drv->drained_poll) {
         return drv->drained_poll(bjob);
     } else {
         return true;
     }
 }

 static void child_job_drained_end(BdrvChild *c, int *drained_end_counter)
 {
     BlockJob *job = c->opaque;
     job_resume(&job->job);
 }

 static bool child_job_can_set_aio_ctx(BdrvChild *c, AioContext *ctx,
                                       GSList **ignore, Error **errp)
 {
     BlockJob *job = c->opaque;
     GSList *l;

     for (l = job->nodes; l; l = l->next) {
         BdrvChild *sibling = l->data;
         if (!bdrv_child_can_set_aio_context(sibling, ctx, ignore, errp)) {
             return false;
         }
     }
     return true;
 }

 static void child_job_set_aio_ctx(BdrvChild *c, AioContext *ctx,
                                   GSList **ignore)
 {
     BlockJob *job = c->opaque;
     GSList *l;

     for (l = job->nodes; l; l = l->next) {
         BdrvChild *sibling = l->data;
         if (g_slist_find(*ignore, sibling)) {
             continue;
         }
         *ignore = g_slist_prepend(*ignore, sibling);
         bdrv_set_aio_context_ignore(sibling->bs, ctx, ignore);
     }

     job->job.aio_context = ctx;
 }

 static const BdrvChildRole child_job = {
     .get_parent_desc    = child_job_get_parent_desc,
     .drained_begin      = child_job_drained_begin,
     .drained_poll       = child_job_drained_poll,
     .drained_end        = child_job_drained_end,
     .can_set_aio_ctx    = child_job_can_set_aio_ctx,
     .set_aio_ctx        = child_job_set_aio_ctx,
     .stay_at_node       = true,
 };

 void block_job_remove_all_bdrv(BlockJob *job)
 {
     GSList *l;
     for (l = job->nodes; l; l = l->next) {
         BdrvChild *c = l->data;
         bdrv_op_unblock_all(c->bs, job->blocker);
         bdrv_root_unref_child(c);
     }
     g_slist_free(job->nodes);
     job->nodes = NULL;
 }

 bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs)
 {
     GSList *el;

     for (el = job->nodes; el; el = el->next) {
         BdrvChild *c = el->data;
         if (c->bs == bs) {
             return true;
         }
     }

     return false;
 }

 int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
                        uint64_t perm, uint64_t shared_perm, Error **errp)
 {
     BdrvChild *c;

     bdrv_ref(bs);
     if (job->job.aio_context != qemu_get_aio_context()) {
         aio_context_release(job->job.aio_context);
     }
     c = bdrv_root_attach_child(bs, name, &child_job, job->job.aio_context,
                                perm, shared_perm, job, errp);
     if (job->job.aio_context != qemu_get_aio_context()) {
         aio_context_acquire(job->job.aio_context);
     }
     if (c == NULL) {
         return -EPERM;
     }

     job->nodes = g_slist_prepend(job->nodes, c);
     bdrv_op_block_all(bs, job->blocker);

     return 0;
 }

 static void block_job_on_idle(Notifier *n, void *opaque)
 {
     aio_wait_kick();
 }

 bool block_job_is_internal(BlockJob *job)
 {
     return (job->job.id == NULL);
 }

 const BlockJobDriver *block_job_driver(BlockJob *job)
 {
     return container_of(job->job.driver, BlockJobDriver, job_driver);
 }

 /* Assumes the job_mutex is held */
 static bool job_timer_pending(Job *job)
 {
     return timer_pending(&job->sleep_timer);
 }

 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
 {
     int64_t old_speed = job->speed;

     if (job_apply_verb(&job->job, JOB_VERB_SET_SPEED, errp)) {
         return;
     }
     if (speed < 0) {
         error_setg(errp, QERR_INVALID_PARAMETER, "speed");
         return;
     }

     ratelimit_set_speed(&job->limit, speed, BLOCK_JOB_SLICE_TIME);

     job->speed = speed;
     if (speed && speed <= old_speed) {
         return;
     }

     /* kick only if a timer is pending */
     job_enter_cond(&job->job, job_timer_pending);
 }

 int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n)
 {
     if (!job->speed) {
         return 0;
     }

     return ratelimit_calculate_delay(&job->limit, n);
 }

 BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
 {
     BlockJobInfo *info;

     if (block_job_is_internal(job)) {
         error_setg(errp, "Cannot query QEMU internal jobs");
         return NULL;
     }
     info = g_new0(BlockJobInfo, 1);
     info->type      = g_strdup(job_type_str(&job->job));
     info->device    = g_strdup(job->job.id);
     info->busy      = atomic_read(&job->job.busy);
     info->paused    = job->job.pause_count > 0;
     info->offset    = job->job.progress_current;
     info->len       = job->job.progress_total;
     info->speed     = job->speed;
     info->io_status = job->iostatus;
     info->ready     = job_is_ready(&job->job),
     info->status    = job->job.status;
     info->auto_finalize = job->job.auto_finalize;
     info->auto_dismiss  = job->job.auto_dismiss;
     info->has_error = job->job.ret != 0;
     info->error     = job->job.ret ? g_strdup(strerror(-job->job.ret)) : NULL;
     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;
     }
 }

 static void block_job_event_cancelled(Notifier *n, void *opaque)
 {
     BlockJob *job = opaque;

     if (block_job_is_internal(job)) {
         return;
     }

     qapi_event_send_block_job_cancelled(job_type(&job->job),
                                         job->job.id,
                                         job->job.progress_total,
                                         job->job.progress_current,
                                         job->speed);
 }

 static void block_job_event_completed(Notifier *n, void *opaque)
 {
     BlockJob *job = opaque;
     const char *msg = NULL;

     if (block_job_is_internal(job)) {
         return;
     }

     if (job->job.ret < 0) {
         msg = strerror(-job->job.ret);
     }

     qapi_event_send_block_job_completed(job_type(&job->job),
                                         job->job.id,
                                         job->job.progress_total,
                                         job->job.progress_current,
                                         job->speed,
                                         !!msg,
                                         msg);
 }

 static void block_job_event_pending(Notifier *n, void *opaque)
 {
     BlockJob *job = opaque;

     if (block_job_is_internal(job)) {
         return;
     }

     qapi_event_send_block_job_pending(job_type(&job->job),
                                       job->job.id);
 }

 static void block_job_event_ready(Notifier *n, void *opaque)
 {
     BlockJob *job = opaque;

     if (block_job_is_internal(job)) {
         return;
     }

     qapi_event_send_block_job_ready(job_type(&job->job),
                                     job->job.id,
                                     job->job.progress_total,
                                     job->job.progress_current,
                                     job->speed);
 }


 /*
  * API for block job drivers and the block layer.  These functions are
  * declared in blockjob_int.h.
  */

 void *block_job_create(const char *job_id, const BlockJobDriver *driver,
                        JobTxn *txn, BlockDriverState *bs, uint64_t perm,
                        uint64_t shared_perm, int64_t speed, int flags,
                        BlockCompletionFunc *cb, void *opaque, Error **errp)
 {
     BlockBackend *blk;
     BlockJob *job;
     int ret;

     if (job_id == NULL && !(flags & JOB_INTERNAL)) {
         job_id = bdrv_get_device_name(bs);
     }

     blk = blk_new(bdrv_get_aio_context(bs), perm, shared_perm);
     ret = blk_insert_bs(blk, bs, errp);
     if (ret < 0) {
         blk_unref(blk);
         return NULL;
     }

     job = job_create(job_id, &driver->job_driver, txn, blk_get_aio_context(blk),
                      flags, cb, opaque, errp);
     if (job == NULL) {
         blk_unref(blk);
         return NULL;
     }

     assert(is_block_job(&job->job));
     assert(job->job.driver->free == &block_job_free);
     assert(job->job.driver->user_resume == &block_job_user_resume);
     assert(job->job.driver->drain == &block_job_drain);

     job->blk = blk;

     job->finalize_cancelled_notifier.notify = block_job_event_cancelled;
     job->finalize_completed_notifier.notify = block_job_event_completed;
     job->pending_notifier.notify = block_job_event_pending;
     job->ready_notifier.notify = block_job_event_ready;
     job->idle_notifier.notify = block_job_on_idle;

     notifier_list_add(&job->job.on_finalize_cancelled,
                       &job->finalize_cancelled_notifier);
     notifier_list_add(&job->job.on_finalize_completed,
                       &job->finalize_completed_notifier);
     notifier_list_add(&job->job.on_pending, &job->pending_notifier);
     notifier_list_add(&job->job.on_ready, &job->ready_notifier);
     notifier_list_add(&job->job.on_idle, &job->idle_notifier);

     error_setg(&job->blocker, "block device is in use by block job: %s",
                job_type_str(&job->job));
     block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort);

     bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);

     blk_set_allow_aio_context_change(blk, true);

     /* 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) {
             job_early_fail(&job->job);
             error_propagate(errp, local_err);
             return NULL;
         }
     }

     return job;
 }

 void block_job_iostatus_reset(BlockJob *job)
 {
     if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
         return;
     }
     assert(job->job.user_paused && job->job.pause_count > 0);
     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
 }

 void block_job_user_resume(Job *job)
 {
     BlockJob *bjob = container_of(job, BlockJob, job);
     block_job_iostatus_reset(bjob);
 }

 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
                                         int is_read, int error)
 {
     BlockErrorAction action;

     switch (on_err) {
     case BLOCKDEV_ON_ERROR_ENOSPC:
     case BLOCKDEV_ON_ERROR_AUTO:
         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();
     }
     if (!block_job_is_internal(job)) {
         qapi_event_send_block_job_error(job->job.id,
                                         is_read ? IO_OPERATION_TYPE_READ :
                                         IO_OPERATION_TYPE_WRITE,
                                         action);
     }
     if (action == BLOCK_ERROR_ACTION_STOP) {
         if (!job->job.user_paused) {
             job_pause(&job->job);
             /* make the pause user visible, which will be resumed from QMP. */
             job->job.user_paused = true;
         }
         block_job_iostatus_set_err(job, error);
     }
     return action;
 }
	/*
	* 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 "qemu/osdep.h"
	#include "block/block.h"
	#include "block/blockjob_int.h"
	#include "block/block_int.h"
	#include "block/trace.h"
	#include "sysemu/block-backend.h"
	#include "qapi/error.h"
	#include "qapi/qapi-events-block-core.h"
	#include "qapi/qmp/qerror.h"
	#include "qemu/coroutine.h"
	#include "qemu/main-loop.h"
	#include "qemu/timer.h"

	/*
	* The block job API is composed of two categories of functions.
	*
	* The first includes functions used by the monitor. The monitor is
	* peculiar in that it accesses the block job list with block_job_get, and
	* therefore needs consistency across block_job_get and the actual operation
	* (e.g. block_job_set_speed). The consistency is achieved with
	* aio_context_acquire/release. These functions are declared in blockjob.h.
	*
	* The second includes functions used by the block job drivers and sometimes
	* by the core block layer. These do not care about locking, because the
	* whole coroutine runs under the AioContext lock, and are declared in
	* blockjob_int.h.
	*/

	static bool is_block_job(Job *job)
	{
	return job_type(job) == JOB_TYPE_BACKUP \|\|
	job_type(job) == JOB_TYPE_COMMIT \|\|
	job_type(job) == JOB_TYPE_MIRROR \|\|
	job_type(job) == JOB_TYPE_STREAM;
	}

	BlockJob block_job_next(BlockJob bjob)
	{
	Job *job = bjob ? &bjob->job : NULL;

	do {
	job = job_next(job);
	} while (job && !is_block_job(job));

	return job ? container_of(job, BlockJob, job) : NULL;
	}

	BlockJob block_job_get(const char id)
	{
	Job *job = job_get(id);

	if (job && is_block_job(job)) {
	return container_of(job, BlockJob, job);
	} else {
	return NULL;
	}
	}

	void block_job_free(Job *job)
	{
	BlockJob *bjob = container_of(job, BlockJob, job);

	block_job_remove_all_bdrv(bjob);
	blk_unref(bjob->blk);
	error_free(bjob->blocker);
	}

	void block_job_drain(Job *job)
	{
	BlockJob *bjob = container_of(job, BlockJob, job);
	const JobDriver *drv = job->driver;
	BlockJobDriver *bjdrv = container_of(drv, BlockJobDriver, job_driver);

	blk_drain(bjob->blk);
	if (bjdrv->drain) {
	bjdrv->drain(bjob);
	}
	}

	static char child_job_get_parent_desc(BdrvChild c)
	{
	BlockJob *job = c->opaque;
	return g_strdup_printf("%s job '%s'", job_type_str(&job->job), job->job.id);
	}

	static void child_job_drained_begin(BdrvChild *c)
	{
	BlockJob *job = c->opaque;
	job_pause(&job->job);
	}

	static bool child_job_drained_poll(BdrvChild *c)
	{
	BlockJob *bjob = c->opaque;
	Job *job = &bjob->job;
	const BlockJobDriver *drv = block_job_driver(bjob);

	/* An inactive or completed job doesn't have any pending requests. Jobs
	* with !job->busy are either already paused or have a pause point after
	* being reentered, so no job driver code will run before they pause. */
	if (!job->busy \|\| job_is_completed(job)) {
	return false;
	}

	/* Otherwise, assume that it isn't fully stopped yet, but allow the job to
	* override this assumption. */
	if (drv->drained_poll) {
	return drv->drained_poll(bjob);
	} else {
	return true;
	}
	}

	static void child_job_drained_end(BdrvChild c, int drained_end_counter)
	{
	BlockJob *job = c->opaque;
	job_resume(&job->job);
	}

	static bool child_job_can_set_aio_ctx(BdrvChild c, AioContext ctx,
	GSList ignore, Error errp)
	{
	BlockJob *job = c->opaque;
	GSList *l;

	for (l = job->nodes; l; l = l->next) {
	BdrvChild *sibling = l->data;
	if (!bdrv_child_can_set_aio_context(sibling, ctx, ignore, errp)) {
	return false;
	}
	}
	return true;
	}

	static void child_job_set_aio_ctx(BdrvChild c, AioContext ctx,
	GSList **ignore)
	{
	BlockJob *job = c->opaque;
	GSList *l;

	for (l = job->nodes; l; l = l->next) {
	BdrvChild *sibling = l->data;
	if (g_slist_find(*ignore, sibling)) {
	continue;
	}
	ignore = g_slist_prepend(ignore, sibling);
	bdrv_set_aio_context_ignore(sibling->bs, ctx, ignore);
	}

	job->job.aio_context = ctx;
	}

	static const BdrvChildRole child_job = {
	.get_parent_desc = child_job_get_parent_desc,
	.drained_begin = child_job_drained_begin,
	.drained_poll = child_job_drained_poll,
	.drained_end = child_job_drained_end,
	.can_set_aio_ctx = child_job_can_set_aio_ctx,
	.set_aio_ctx = child_job_set_aio_ctx,
	.stay_at_node = true,
	};

	void block_job_remove_all_bdrv(BlockJob *job)
	{
	GSList *l;
	for (l = job->nodes; l; l = l->next) {
	BdrvChild *c = l->data;
	bdrv_op_unblock_all(c->bs, job->blocker);
	bdrv_root_unref_child(c);
	}
	g_slist_free(job->nodes);
	job->nodes = NULL;
	}

	bool block_job_has_bdrv(BlockJob job, BlockDriverState bs)
	{
	GSList *el;

	for (el = job->nodes; el; el = el->next) {
	BdrvChild *c = el->data;
	if (c->bs == bs) {
	return true;
	}
	}

	return false;
	}

	int block_job_add_bdrv(BlockJob job, const char name, BlockDriverState *bs,
	uint64_t perm, uint64_t shared_perm, Error **errp)
	{
	BdrvChild *c;

	bdrv_ref(bs);
	if (job->job.aio_context != qemu_get_aio_context()) {
	aio_context_release(job->job.aio_context);
	}
	c = bdrv_root_attach_child(bs, name, &child_job, job->job.aio_context,
	perm, shared_perm, job, errp);
	if (job->job.aio_context != qemu_get_aio_context()) {
	aio_context_acquire(job->job.aio_context);
	}
	if (c == NULL) {
	return -EPERM;
	}

	job->nodes = g_slist_prepend(job->nodes, c);
	bdrv_op_block_all(bs, job->blocker);

	return 0;
	}

	static void block_job_on_idle(Notifier n, void opaque)
	{
	aio_wait_kick();
	}

	bool block_job_is_internal(BlockJob *job)
	{
	return (job->job.id == NULL);
	}

	const BlockJobDriver block_job_driver(BlockJob job)
	{
	return container_of(job->job.driver, BlockJobDriver, job_driver);
	}

	/* Assumes the job_mutex is held */
	static bool job_timer_pending(Job *job)
	{
	return timer_pending(&job->sleep_timer);
	}

	void block_job_set_speed(BlockJob job, int64_t speed, Error *errp)
	{
	int64_t old_speed = job->speed;

	if (job_apply_verb(&job->job, JOB_VERB_SET_SPEED, errp)) {
	return;
	}
	if (speed < 0) {
	error_setg(errp, QERR_INVALID_PARAMETER, "speed");
	return;
	}

	ratelimit_set_speed(&job->limit, speed, BLOCK_JOB_SLICE_TIME);

	job->speed = speed;
	if (speed && speed <= old_speed) {
	return;
	}

	/* kick only if a timer is pending */
	job_enter_cond(&job->job, job_timer_pending);
	}

	int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n)
	{
	if (!job->speed) {
	return 0;
	}

	return ratelimit_calculate_delay(&job->limit, n);
	}

	BlockJobInfo block_job_query(BlockJob job, Error **errp)
	{
	BlockJobInfo *info;

	if (block_job_is_internal(job)) {
	error_setg(errp, "Cannot query QEMU internal jobs");
	return NULL;
	}
	info = g_new0(BlockJobInfo, 1);
	info->type = g_strdup(job_type_str(&job->job));
	info->device = g_strdup(job->job.id);
	info->busy = atomic_read(&job->job.busy);
	info->paused = job->job.pause_count > 0;
	info->offset = job->job.progress_current;
	info->len = job->job.progress_total;
	info->speed = job->speed;
	info->io_status = job->iostatus;
	info->ready = job_is_ready(&job->job),
	info->status = job->job.status;
	info->auto_finalize = job->job.auto_finalize;
	info->auto_dismiss = job->job.auto_dismiss;
	info->has_error = job->job.ret != 0;
	info->error = job->job.ret ? g_strdup(strerror(-job->job.ret)) : NULL;
	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;
	}
	}

	static void block_job_event_cancelled(Notifier n, void opaque)
	{
	BlockJob *job = opaque;

	if (block_job_is_internal(job)) {
	return;
	}

	qapi_event_send_block_job_cancelled(job_type(&job->job),
	job->job.id,
	job->job.progress_total,
	job->job.progress_current,
	job->speed);
	}

	static void block_job_event_completed(Notifier n, void opaque)
	{
	BlockJob *job = opaque;
	const char *msg = NULL;

	if (block_job_is_internal(job)) {
	return;
	}

	if (job->job.ret < 0) {
	msg = strerror(-job->job.ret);
	}

	qapi_event_send_block_job_completed(job_type(&job->job),
	job->job.id,
	job->job.progress_total,
	job->job.progress_current,
	job->speed,
	!!msg,
	msg);
	}

	static void block_job_event_pending(Notifier n, void opaque)
	{
	BlockJob *job = opaque;

	if (block_job_is_internal(job)) {
	return;
	}

	qapi_event_send_block_job_pending(job_type(&job->job),
	job->job.id);
	}

	static void block_job_event_ready(Notifier n, void opaque)
	{
	BlockJob *job = opaque;

	if (block_job_is_internal(job)) {
	return;
	}

	qapi_event_send_block_job_ready(job_type(&job->job),
	job->job.id,
	job->job.progress_total,
	job->job.progress_current,
	job->speed);
	}


	/*
	* API for block job drivers and the block layer. These functions are
	* declared in blockjob_int.h.
	*/

	void block_job_create(const char job_id, const BlockJobDriver *driver,
	JobTxn txn, BlockDriverState bs, uint64_t perm,
	uint64_t shared_perm, int64_t speed, int flags,
	BlockCompletionFunc cb, void opaque, Error **errp)
	{
	BlockBackend *blk;
	BlockJob *job;
	int ret;

	if (job_id == NULL && !(flags & JOB_INTERNAL)) {
	job_id = bdrv_get_device_name(bs);
	}

	blk = blk_new(bdrv_get_aio_context(bs), perm, shared_perm);
	ret = blk_insert_bs(blk, bs, errp);
	if (ret < 0) {
	blk_unref(blk);
	return NULL;
	}

	job = job_create(job_id, &driver->job_driver, txn, blk_get_aio_context(blk),
	flags, cb, opaque, errp);
	if (job == NULL) {
	blk_unref(blk);
	return NULL;
	}

	assert(is_block_job(&job->job));
	assert(job->job.driver->free == &block_job_free);
	assert(job->job.driver->user_resume == &block_job_user_resume);
	assert(job->job.driver->drain == &block_job_drain);

	job->blk = blk;

	job->finalize_cancelled_notifier.notify = block_job_event_cancelled;
	job->finalize_completed_notifier.notify = block_job_event_completed;
	job->pending_notifier.notify = block_job_event_pending;
	job->ready_notifier.notify = block_job_event_ready;
	job->idle_notifier.notify = block_job_on_idle;

	notifier_list_add(&job->job.on_finalize_cancelled,
	&job->finalize_cancelled_notifier);
	notifier_list_add(&job->job.on_finalize_completed,
	&job->finalize_completed_notifier);
	notifier_list_add(&job->job.on_pending, &job->pending_notifier);
	notifier_list_add(&job->job.on_ready, &job->ready_notifier);
	notifier_list_add(&job->job.on_idle, &job->idle_notifier);

	error_setg(&job->blocker, "block device is in use by block job: %s",
	job_type_str(&job->job));
	block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort);

	bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);

	blk_set_allow_aio_context_change(blk, true);

	/* 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) {
	job_early_fail(&job->job);
	error_propagate(errp, local_err);
	return NULL;
	}
	}

	return job;
	}

	void block_job_iostatus_reset(BlockJob *job)
	{
	if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
	return;
	}
	assert(job->job.user_paused && job->job.pause_count > 0);
	job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
	}

	void block_job_user_resume(Job *job)
	{
	BlockJob *bjob = container_of(job, BlockJob, job);
	block_job_iostatus_reset(bjob);
	}

	BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
	int is_read, int error)
	{
	BlockErrorAction action;

	switch (on_err) {
	case BLOCKDEV_ON_ERROR_ENOSPC:
	case BLOCKDEV_ON_ERROR_AUTO:
	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();
	}
	if (!block_job_is_internal(job)) {
	qapi_event_send_block_job_error(job->job.id,
	is_read ? IO_OPERATION_TYPE_READ :
	IO_OPERATION_TYPE_WRITE,
	action);
	}
	if (action == BLOCK_ERROR_ACTION_STOP) {
	if (!job->job.user_paused) {
	job_pause(&job->job);
	/* make the pause user visible, which will be resumed from QMP. */
	job->job.user_paused = true;
	}
	block_job_iostatus_set_err(job, error);
	}
	return action;
	}