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Diffstat (limited to 'job.c')
| -rw-r--r-- | job.c | 1000 |
1 files changed, 1000 insertions, 0 deletions
@@ -0,0 +1,1000 @@ +/* + * Background jobs (long-running operations) + * + * Copyright (c) 2011 IBM Corp. + * Copyright (c) 2012, 2018 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 "qemu-common.h" +#include "qapi/error.h" +#include "qemu/job.h" +#include "qemu/id.h" +#include "qemu/main-loop.h" +#include "trace-root.h" +#include "qapi/qapi-events-job.h" + +static QLIST_HEAD(, Job) jobs = QLIST_HEAD_INITIALIZER(jobs); + +/* Job State Transition Table */ +bool JobSTT[JOB_STATUS__MAX][JOB_STATUS__MAX] = { + /* U, C, R, P, Y, S, W, D, X, E, N */ + /* U: */ [JOB_STATUS_UNDEFINED] = {0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0}, + /* C: */ [JOB_STATUS_CREATED] = {0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1}, + /* R: */ [JOB_STATUS_RUNNING] = {0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0}, + /* P: */ [JOB_STATUS_PAUSED] = {0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0}, + /* Y: */ [JOB_STATUS_READY] = {0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0}, + /* S: */ [JOB_STATUS_STANDBY] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0}, + /* W: */ [JOB_STATUS_WAITING] = {0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0}, + /* D: */ [JOB_STATUS_PENDING] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0}, + /* X: */ [JOB_STATUS_ABORTING] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0}, + /* E: */ [JOB_STATUS_CONCLUDED] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}, + /* N: */ [JOB_STATUS_NULL] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, +}; + +bool JobVerbTable[JOB_VERB__MAX][JOB_STATUS__MAX] = { + /* U, C, R, P, Y, S, W, D, X, E, N */ + [JOB_VERB_CANCEL] = {0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0}, + [JOB_VERB_PAUSE] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, + [JOB_VERB_RESUME] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, + [JOB_VERB_SET_SPEED] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, + [JOB_VERB_COMPLETE] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0}, + [JOB_VERB_FINALIZE] = {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0}, + [JOB_VERB_DISMISS] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0}, +}; + +/* Transactional group of jobs */ +struct JobTxn { + + /* Is this txn being cancelled? */ + bool aborting; + + /* List of jobs */ + QLIST_HEAD(, Job) jobs; + + /* Reference count */ + int refcnt; +}; + +/* Right now, this mutex is only needed to synchronize accesses to job->busy + * and job->sleep_timer, such as concurrent calls to job_do_yield and + * job_enter. */ +static QemuMutex job_mutex; + +static void job_lock(void) +{ + qemu_mutex_lock(&job_mutex); +} + +static void job_unlock(void) +{ + qemu_mutex_unlock(&job_mutex); +} + +static void __attribute__((__constructor__)) job_init(void) +{ + qemu_mutex_init(&job_mutex); +} + +JobTxn *job_txn_new(void) +{ + JobTxn *txn = g_new0(JobTxn, 1); + QLIST_INIT(&txn->jobs); + txn->refcnt = 1; + return txn; +} + +static void job_txn_ref(JobTxn *txn) +{ + txn->refcnt++; +} + +void job_txn_unref(JobTxn *txn) +{ + if (txn && --txn->refcnt == 0) { + g_free(txn); + } +} + +void job_txn_add_job(JobTxn *txn, Job *job) +{ + if (!txn) { + return; + } + + assert(!job->txn); + job->txn = txn; + + QLIST_INSERT_HEAD(&txn->jobs, job, txn_list); + job_txn_ref(txn); +} + +static void job_txn_del_job(Job *job) +{ + if (job->txn) { + QLIST_REMOVE(job, txn_list); + job_txn_unref(job->txn); + job->txn = NULL; + } +} + +static int job_txn_apply(JobTxn *txn, int fn(Job *), bool lock) +{ + AioContext *ctx; + Job *job, *next; + int rc = 0; + + QLIST_FOREACH_SAFE(job, &txn->jobs, txn_list, next) { + if (lock) { + ctx = job->aio_context; + aio_context_acquire(ctx); + } + rc = fn(job); + if (lock) { + aio_context_release(ctx); + } + if (rc) { + break; + } + } + return rc; +} + +bool job_is_internal(Job *job) +{ + return (job->id == NULL); +} + +static void job_state_transition(Job *job, JobStatus s1) +{ + JobStatus s0 = job->status; + assert(s1 >= 0 && s1 <= JOB_STATUS__MAX); + trace_job_state_transition(job, job->ret, + JobSTT[s0][s1] ? "allowed" : "disallowed", + JobStatus_str(s0), JobStatus_str(s1)); + assert(JobSTT[s0][s1]); + job->status = s1; + + if (!job_is_internal(job) && s1 != s0) { + qapi_event_send_job_status_change(job->id, job->status, &error_abort); + } +} + +int job_apply_verb(Job *job, JobVerb verb, Error **errp) +{ + JobStatus s0 = job->status; + assert(verb >= 0 && verb <= JOB_VERB__MAX); + trace_job_apply_verb(job, JobStatus_str(s0), JobVerb_str(verb), + JobVerbTable[verb][s0] ? "allowed" : "prohibited"); + if (JobVerbTable[verb][s0]) { + return 0; + } + error_setg(errp, "Job '%s' in state '%s' cannot accept command verb '%s'", + job->id, JobStatus_str(s0), JobVerb_str(verb)); + return -EPERM; +} + +JobType job_type(const Job *job) +{ + return job->driver->job_type; +} + +const char *job_type_str(const Job *job) +{ + return JobType_str(job_type(job)); +} + +bool job_is_cancelled(Job *job) +{ + return job->cancelled; +} + +bool job_is_ready(Job *job) +{ + switch (job->status) { + case JOB_STATUS_UNDEFINED: + case JOB_STATUS_CREATED: + case JOB_STATUS_RUNNING: + case JOB_STATUS_PAUSED: + case JOB_STATUS_WAITING: + case JOB_STATUS_PENDING: + case JOB_STATUS_ABORTING: + case JOB_STATUS_CONCLUDED: + case JOB_STATUS_NULL: + return false; + case JOB_STATUS_READY: + case JOB_STATUS_STANDBY: + return true; + default: + g_assert_not_reached(); + } + return false; +} + +bool job_is_completed(Job *job) +{ + switch (job->status) { + case JOB_STATUS_UNDEFINED: + case JOB_STATUS_CREATED: + case JOB_STATUS_RUNNING: + case JOB_STATUS_PAUSED: + case JOB_STATUS_READY: + case JOB_STATUS_STANDBY: + return false; + case JOB_STATUS_WAITING: + case JOB_STATUS_PENDING: + case JOB_STATUS_ABORTING: + case JOB_STATUS_CONCLUDED: + case JOB_STATUS_NULL: + return true; + default: + g_assert_not_reached(); + } + return false; +} + +static bool job_started(Job *job) +{ + return job->co; +} + +static bool job_should_pause(Job *job) +{ + return job->pause_count > 0; +} + +Job *job_next(Job *job) +{ + if (!job) { + return QLIST_FIRST(&jobs); + } + return QLIST_NEXT(job, job_list); +} + +Job *job_get(const char *id) +{ + Job *job; + + QLIST_FOREACH(job, &jobs, job_list) { + if (job->id && !strcmp(id, job->id)) { + return job; + } + } + + return NULL; +} + +static void job_sleep_timer_cb(void *opaque) +{ + Job *job = opaque; + + job_enter(job); +} + +void *job_create(const char *job_id, const JobDriver *driver, JobTxn *txn, + AioContext *ctx, int flags, BlockCompletionFunc *cb, + void *opaque, Error **errp) +{ + Job *job; + + if (job_id) { + if (flags & JOB_INTERNAL) { + error_setg(errp, "Cannot specify job ID for internal job"); + return NULL; + } + if (!id_wellformed(job_id)) { + error_setg(errp, "Invalid job ID '%s'", job_id); + return NULL; + } + if (job_get(job_id)) { + error_setg(errp, "Job ID '%s' already in use", job_id); + return NULL; + } + } else if (!(flags & JOB_INTERNAL)) { + error_setg(errp, "An explicit job ID is required"); + return NULL; + } + + job = g_malloc0(driver->instance_size); + job->driver = driver; + job->id = g_strdup(job_id); + job->refcnt = 1; + job->aio_context = ctx; + job->busy = false; + job->paused = true; + job->pause_count = 1; + job->auto_finalize = !(flags & JOB_MANUAL_FINALIZE); + job->auto_dismiss = !(flags & JOB_MANUAL_DISMISS); + job->cb = cb; + job->opaque = opaque; + + notifier_list_init(&job->on_finalize_cancelled); + notifier_list_init(&job->on_finalize_completed); + notifier_list_init(&job->on_pending); + notifier_list_init(&job->on_ready); + + job_state_transition(job, JOB_STATUS_CREATED); + aio_timer_init(qemu_get_aio_context(), &job->sleep_timer, + QEMU_CLOCK_REALTIME, SCALE_NS, + job_sleep_timer_cb, job); + + QLIST_INSERT_HEAD(&jobs, job, job_list); + + /* Single jobs are modeled as single-job transactions for sake of + * consolidating the job management logic */ + if (!txn) { + txn = job_txn_new(); + job_txn_add_job(txn, job); + job_txn_unref(txn); + } else { + job_txn_add_job(txn, job); + } + + return job; +} + +void job_ref(Job *job) +{ + ++job->refcnt; +} + +void job_unref(Job *job) +{ + if (--job->refcnt == 0) { + assert(job->status == JOB_STATUS_NULL); + assert(!timer_pending(&job->sleep_timer)); + assert(!job->txn); + + if (job->driver->free) { + job->driver->free(job); + } + + QLIST_REMOVE(job, job_list); + + g_free(job->id); + g_free(job); + } +} + +void job_progress_update(Job *job, uint64_t done) +{ + job->progress_current += done; +} + +void job_progress_set_remaining(Job *job, uint64_t remaining) +{ + job->progress_total = job->progress_current + remaining; +} + +void job_event_cancelled(Job *job) +{ + notifier_list_notify(&job->on_finalize_cancelled, job); +} + +void job_event_completed(Job *job) +{ + notifier_list_notify(&job->on_finalize_completed, job); +} + +static void job_event_pending(Job *job) +{ + notifier_list_notify(&job->on_pending, job); +} + +static void job_event_ready(Job *job) +{ + notifier_list_notify(&job->on_ready, job); +} + +void job_enter_cond(Job *job, bool(*fn)(Job *job)) +{ + if (!job_started(job)) { + return; + } + if (job->deferred_to_main_loop) { + return; + } + + job_lock(); + if (job->busy) { + job_unlock(); + return; + } + + if (fn && !fn(job)) { + job_unlock(); + return; + } + + assert(!job->deferred_to_main_loop); + timer_del(&job->sleep_timer); + job->busy = true; + job_unlock(); + aio_co_wake(job->co); +} + +void job_enter(Job *job) +{ + job_enter_cond(job, NULL); +} + +/* Yield, and schedule a timer to reenter the coroutine after @ns nanoseconds. + * Reentering the job coroutine with job_enter() before the timer has expired + * is allowed and cancels the timer. + * + * If @ns is (uint64_t) -1, no timer is scheduled and job_enter() must be + * called explicitly. */ +static void coroutine_fn job_do_yield(Job *job, uint64_t ns) +{ + job_lock(); + if (ns != -1) { + timer_mod(&job->sleep_timer, ns); + } + job->busy = false; + job_unlock(); + qemu_coroutine_yield(); + + /* Set by job_enter_cond() before re-entering the coroutine. */ + assert(job->busy); +} + +void coroutine_fn job_pause_point(Job *job) +{ + assert(job && job_started(job)); + + if (!job_should_pause(job)) { + return; + } + if (job_is_cancelled(job)) { + return; + } + + if (job->driver->pause) { + job->driver->pause(job); + } + + if (job_should_pause(job) && !job_is_cancelled(job)) { + JobStatus status = job->status; + job_state_transition(job, status == JOB_STATUS_READY + ? JOB_STATUS_STANDBY + : JOB_STATUS_PAUSED); + job->paused = true; + job_do_yield(job, -1); + job->paused = false; + job_state_transition(job, status); + } + + if (job->driver->resume) { + job->driver->resume(job); + } +} + +void job_yield(Job *job) +{ + assert(job->busy); + + /* Check cancellation *before* setting busy = false, too! */ + if (job_is_cancelled(job)) { + return; + } + + if (!job_should_pause(job)) { + job_do_yield(job, -1); + } + + job_pause_point(job); +} + +void coroutine_fn job_sleep_ns(Job *job, int64_t ns) +{ + assert(job->busy); + + /* Check cancellation *before* setting busy = false, too! */ + if (job_is_cancelled(job)) { + return; + } + + if (!job_should_pause(job)) { + job_do_yield(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + ns); + } + + job_pause_point(job); +} + +void job_drain(Job *job) +{ + /* If job is !busy this kicks it into the next pause point. */ + job_enter(job); + + if (job->driver->drain) { + job->driver->drain(job); + } +} + + +/** + * All jobs must allow a pause point before entering their job proper. This + * ensures that jobs can be paused prior to being started, then resumed later. + */ +static void coroutine_fn job_co_entry(void *opaque) +{ + Job *job = opaque; + + assert(job && job->driver && job->driver->start); + job_pause_point(job); + job->driver->start(job); +} + + +void job_start(Job *job) +{ + assert(job && !job_started(job) && job->paused && + job->driver && job->driver->start); + job->co = qemu_coroutine_create(job_co_entry, job); + job->pause_count--; + job->busy = true; + job->paused = false; + job_state_transition(job, JOB_STATUS_RUNNING); + aio_co_enter(job->aio_context, job->co); +} + +/* Assumes the block_job_mutex is held */ +static bool job_timer_not_pending(Job *job) +{ + return !timer_pending(&job->sleep_timer); +} + +void job_pause(Job *job) +{ + job->pause_count++; +} + +void job_resume(Job *job) +{ + assert(job->pause_count > 0); + job->pause_count--; + if (job->pause_count) { + return; + } + + /* kick only if no timer is pending */ + job_enter_cond(job, job_timer_not_pending); +} + +void job_user_pause(Job *job, Error **errp) +{ + if (job_apply_verb(job, JOB_VERB_PAUSE, errp)) { + return; + } + if (job->user_paused) { + error_setg(errp, "Job is already paused"); + return; + } + job->user_paused = true; + job_pause(job); +} + +bool job_user_paused(Job *job) +{ + return job->user_paused; +} + +void job_user_resume(Job *job, Error **errp) +{ + assert(job); + if (!job->user_paused || job->pause_count <= 0) { + error_setg(errp, "Can't resume a job that was not paused"); + return; + } + if (job_apply_verb(job, JOB_VERB_RESUME, errp)) { + return; + } + if (job->driver->user_resume) { + job->driver->user_resume(job); + } + job->user_paused = false; + job_resume(job); +} + +static void job_do_dismiss(Job *job) +{ + assert(job); + job->busy = false; + job->paused = false; + job->deferred_to_main_loop = true; + + job_txn_del_job(job); + + job_state_transition(job, JOB_STATUS_NULL); + job_unref(job); +} + +void job_dismiss(Job **jobptr, Error **errp) +{ + Job *job = *jobptr; + /* similarly to _complete, this is QMP-interface only. */ + assert(job->id); + if (job_apply_verb(job, JOB_VERB_DISMISS, errp)) { + return; + } + + job_do_dismiss(job); + *jobptr = NULL; +} + +void job_early_fail(Job *job) +{ + assert(job->status == JOB_STATUS_CREATED); + job_do_dismiss(job); +} + +static void job_conclude(Job *job) +{ + job_state_transition(job, JOB_STATUS_CONCLUDED); + if (job->auto_dismiss || !job_started(job)) { + job_do_dismiss(job); + } +} + +static void job_update_rc(Job *job) +{ + if (!job->ret && job_is_cancelled(job)) { + job->ret = -ECANCELED; + } + if (job->ret) { + job_state_transition(job, JOB_STATUS_ABORTING); + } +} + +static void job_commit(Job *job) +{ + assert(!job->ret); + if (job->driver->commit) { + job->driver->commit(job); + } +} + +static void job_abort(Job *job) +{ + assert(job->ret); + if (job->driver->abort) { + job->driver->abort(job); + } +} + +static void job_clean(Job *job) +{ + if (job->driver->clean) { + job->driver->clean(job); + } +} + +static int job_finalize_single(Job *job) +{ + assert(job_is_completed(job)); + + /* Ensure abort is called for late-transactional failures */ + job_update_rc(job); + + if (!job->ret) { + job_commit(job); + } else { + job_abort(job); + } + job_clean(job); + + if (job->cb) { + job->cb(job->opaque, job->ret); + } + + /* Emit events only if we actually started */ + if (job_started(job)) { + if (job_is_cancelled(job)) { + job_event_cancelled(job); + } else { + job_event_completed(job); + } + } + + job_txn_del_job(job); + job_conclude(job); + return 0; +} + +static void job_cancel_async(Job *job, bool force) +{ + if (job->user_paused) { + /* Do not call job_enter here, the caller will handle it. */ + job->user_paused = false; + if (job->driver->user_resume) { + job->driver->user_resume(job); + } + assert(job->pause_count > 0); + job->pause_count--; + } + job->cancelled = true; + /* To prevent 'force == false' overriding a previous 'force == true' */ + job->force_cancel |= force; +} + +static void job_completed_txn_abort(Job *job) +{ + AioContext *ctx; + JobTxn *txn = job->txn; + Job *other_job; + + if (txn->aborting) { + /* + * We are cancelled by another job, which will handle everything. + */ + return; + } + txn->aborting = true; + job_txn_ref(txn); + + /* We are the first failed job. Cancel other jobs. */ + QLIST_FOREACH(other_job, &txn->jobs, txn_list) { + ctx = other_job->aio_context; + aio_context_acquire(ctx); + } + + /* Other jobs are effectively cancelled by us, set the status for + * them; this job, however, may or may not be cancelled, depending + * on the caller, so leave it. */ + QLIST_FOREACH(other_job, &txn->jobs, txn_list) { + if (other_job != job) { + job_cancel_async(other_job, false); + } + } + while (!QLIST_EMPTY(&txn->jobs)) { + other_job = QLIST_FIRST(&txn->jobs); + ctx = other_job->aio_context; + if (!job_is_completed(other_job)) { + assert(job_is_cancelled(other_job)); + job_finish_sync(other_job, NULL, NULL); + } + job_finalize_single(other_job); + aio_context_release(ctx); + } + + job_txn_unref(txn); +} + +static int job_prepare(Job *job) +{ + if (job->ret == 0 && job->driver->prepare) { + job->ret = job->driver->prepare(job); + } + return job->ret; +} + +static int job_needs_finalize(Job *job) +{ + return !job->auto_finalize; +} + +static void job_do_finalize(Job *job) +{ + int rc; + assert(job && job->txn); + + /* prepare the transaction to complete */ + rc = job_txn_apply(job->txn, job_prepare, true); + if (rc) { + job_completed_txn_abort(job); + } else { + job_txn_apply(job->txn, job_finalize_single, true); + } +} + +void job_finalize(Job *job, Error **errp) +{ + assert(job && job->id); + if (job_apply_verb(job, JOB_VERB_FINALIZE, errp)) { + return; + } + job_do_finalize(job); +} + +static int job_transition_to_pending(Job *job) +{ + job_state_transition(job, JOB_STATUS_PENDING); + if (!job->auto_finalize) { + job_event_pending(job); + } + return 0; +} + +void job_transition_to_ready(Job *job) +{ + job_state_transition(job, JOB_STATUS_READY); + job_event_ready(job); +} + +static void job_completed_txn_success(Job *job) +{ + JobTxn *txn = job->txn; + Job *other_job; + + job_state_transition(job, JOB_STATUS_WAITING); + + /* + * Successful completion, see if there are other running jobs in this + * txn. + */ + QLIST_FOREACH(other_job, &txn->jobs, txn_list) { + if (!job_is_completed(other_job)) { + return; + } + assert(other_job->ret == 0); + } + + job_txn_apply(txn, job_transition_to_pending, false); + + /* If no jobs need manual finalization, automatically do so */ + if (job_txn_apply(txn, job_needs_finalize, false) == 0) { + job_do_finalize(job); + } +} + +void job_completed(Job *job, int ret) +{ + assert(job && job->txn && !job_is_completed(job)); + job->ret = ret; + job_update_rc(job); + trace_job_completed(job, ret, job->ret); + if (job->ret) { + job_completed_txn_abort(job); + } else { + job_completed_txn_success(job); + } +} + +void job_cancel(Job *job, bool force) +{ + if (job->status == JOB_STATUS_CONCLUDED) { + job_do_dismiss(job); + return; + } + job_cancel_async(job, force); + if (!job_started(job)) { + job_completed(job, -ECANCELED); + } else if (job->deferred_to_main_loop) { + job_completed_txn_abort(job); + } else { + job_enter(job); + } +} + +void job_user_cancel(Job *job, bool force, Error **errp) +{ + if (job_apply_verb(job, JOB_VERB_CANCEL, errp)) { + return; + } + job_cancel(job, force); +} + +/* A wrapper around job_cancel() taking an Error ** parameter so it may be + * used with job_finish_sync() without the need for (rather nasty) function + * pointer casts there. */ +static void job_cancel_err(Job *job, Error **errp) +{ + job_cancel(job, false); +} + +int job_cancel_sync(Job *job) +{ + return job_finish_sync(job, &job_cancel_err, NULL); +} + +void job_cancel_sync_all(void) +{ + Job *job; + AioContext *aio_context; + + while ((job = job_next(NULL))) { + aio_context = job->aio_context; + aio_context_acquire(aio_context); + job_cancel_sync(job); + aio_context_release(aio_context); + } +} + +int job_complete_sync(Job *job, Error **errp) +{ + return job_finish_sync(job, job_complete, errp); +} + +void job_complete(Job *job, Error **errp) +{ + /* Should not be reachable via external interface for internal jobs */ + assert(job->id); + if (job_apply_verb(job, JOB_VERB_COMPLETE, errp)) { + return; + } + if (job->pause_count || job_is_cancelled(job) || !job->driver->complete) { + error_setg(errp, "The active block job '%s' cannot be completed", + job->id); + return; + } + + job->driver->complete(job, errp); +} + + +typedef struct { + Job *job; + JobDeferToMainLoopFn *fn; + void *opaque; +} JobDeferToMainLoopData; + +static void job_defer_to_main_loop_bh(void *opaque) +{ + JobDeferToMainLoopData *data = opaque; + Job *job = data->job; + AioContext *aio_context = job->aio_context; + + aio_context_acquire(aio_context); + data->fn(data->job, data->opaque); + aio_context_release(aio_context); + + g_free(data); +} + +void job_defer_to_main_loop(Job *job, JobDeferToMainLoopFn *fn, void *opaque) +{ + JobDeferToMainLoopData *data = g_malloc(sizeof(*data)); + data->job = job; + data->fn = fn; + data->opaque = opaque; + job->deferred_to_main_loop = true; + + aio_bh_schedule_oneshot(qemu_get_aio_context(), + job_defer_to_main_loop_bh, data); +} + +int job_finish_sync(Job *job, void (*finish)(Job *, Error **errp), Error **errp) +{ + Error *local_err = NULL; + int ret; + + job_ref(job); + + if (finish) { + finish(job, &local_err); + } + if (local_err) { + error_propagate(errp, local_err); + job_unref(job); + return -EBUSY; + } + /* job_drain calls job_enter, and it should be enough to induce progress + * until the job completes or moves to the main thread. */ + while (!job->deferred_to_main_loop && !job_is_completed(job)) { + job_drain(job); + } + while (!job_is_completed(job)) { + aio_poll(qemu_get_aio_context(), true); + } + ret = (job_is_cancelled(job) && job->ret == 0) ? -ECANCELED : job->ret; + job_unref(job); + return ret; +} |