*/
#include "qemu/osdep.h"
-#include "qemu-common.h"
#include "qapi/error.h"
#include "qemu/job.h"
#include "qemu/id.h"
-#include "trace-root.h"
+#include "qemu/main-loop.h"
+#include "block/aio-wait.h"
+#include "trace/trace-root.h"
+#include "qapi/qapi-events-job.h"
+/*
+ * The 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 job list with job_get, and
+ * therefore needs consistency across job_get and the actual operation
+ * (e.g. job_user_cancel). To achieve this consistency, the caller
+ * calls job_lock/job_unlock itself around the whole operation.
+ *
+ *
+ * The second includes functions used by the job drivers and sometimes
+ * by the core block layer. These delegate the locking to the callee instead.
+ */
+
+/*
+ * job_mutex protects the jobs list, but also makes the
+ * struct job fields thread-safe.
+ */
+QemuMutex job_mutex;
+
+/* Protected by job_mutex */
static QLIST_HEAD(, Job) jobs = QLIST_HEAD_INITIALIZER(jobs);
/* Job State Transition Table */
[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_COMPLETE] = {0, 0, 0, 0, 1, 1, 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},
};
-/* TODO Make static once the whole state machine is in job.c */
-void job_state_transition(Job *job, JobStatus s1)
+/* Transactional group of jobs */
+struct JobTxn {
+
+ /* Is this txn being cancelled? */
+ bool aborting;
+
+ /* List of jobs */
+ QLIST_HEAD(, Job) jobs;
+
+ /* Reference count */
+ int refcnt;
+};
+
+void job_lock(void)
+{
+ qemu_mutex_lock(&job_mutex);
+}
+
+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;
+}
+
+/* Called with job_mutex held. */
+static void job_txn_ref_locked(JobTxn *txn)
+{
+ txn->refcnt++;
+}
+
+void job_txn_unref_locked(JobTxn *txn)
+{
+ if (txn && --txn->refcnt == 0) {
+ g_free(txn);
+ }
+}
+
+void job_txn_unref(JobTxn *txn)
+{
+ JOB_LOCK_GUARD();
+ job_txn_unref_locked(txn);
+}
+
+/**
+ * @txn: The transaction (may be NULL)
+ * @job: Job to add to the transaction
+ *
+ * Add @job to the transaction. The @job must not already be in a transaction.
+ * The caller must call either job_txn_unref() or job_completed() to release
+ * the reference that is automatically grabbed here.
+ *
+ * If @txn is NULL, the function does nothing.
+ *
+ * Called with job_mutex held.
+ */
+static void job_txn_add_job_locked(JobTxn *txn, Job *job)
+{
+ if (!txn) {
+ return;
+ }
+
+ assert(!job->txn);
+ job->txn = txn;
+
+ QLIST_INSERT_HEAD(&txn->jobs, job, txn_list);
+ job_txn_ref_locked(txn);
+}
+
+/* Called with job_mutex held. */
+static void job_txn_del_job_locked(Job *job)
+{
+ if (job->txn) {
+ QLIST_REMOVE(job, txn_list);
+ job_txn_unref_locked(job->txn);
+ job->txn = NULL;
+ }
+}
+
+/* Called with job_mutex held, but releases it temporarily. */
+static int job_txn_apply_locked(Job *job, int fn(Job *))
+{
+ Job *other_job, *next;
+ JobTxn *txn = job->txn;
+ int rc = 0;
+
+ /*
+ * Similar to job_completed_txn_abort, we take each job's lock before
+ * applying fn, but since we assume that outer_ctx is held by the caller,
+ * we need to release it here to avoid holding the lock twice - which would
+ * break AIO_WAIT_WHILE from within fn.
+ */
+ job_ref_locked(job);
+
+ QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) {
+ rc = fn(other_job);
+ if (rc) {
+ break;
+ }
+ }
+
+ job_unref_locked(job);
+ return rc;
+}
+
+bool job_is_internal(Job *job)
+{
+ return (job->id == NULL);
+}
+
+/* Called with job_mutex held. */
+static void job_state_transition_locked(Job *job, JobStatus s1)
{
JobStatus s0 = job->status;
- assert(s1 >= 0 && s1 <= JOB_STATUS__MAX);
- trace_job_state_transition(job, /* TODO re-enable: job->ret */ 0,
+ 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);
+ }
}
-int job_apply_verb(Job *job, JobVerb verb, Error **errp)
+int job_apply_verb_locked(Job *job, JobVerb verb, Error **errp)
{
JobStatus s0 = job->status;
- assert(verb >= 0 && verb <= JOB_VERB__MAX);
+ 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 JobType_str(job_type(job));
}
+bool job_is_cancelled_locked(Job *job)
+{
+ /* force_cancel may be true only if cancelled is true, too */
+ assert(job->cancelled || !job->force_cancel);
+ return job->force_cancel;
+}
+
bool job_is_cancelled(Job *job)
+{
+ JOB_LOCK_GUARD();
+ return job_is_cancelled_locked(job);
+}
+
+/* Called with job_mutex held. */
+static bool job_cancel_requested_locked(Job *job)
{
return job->cancelled;
}
-Job *job_next(Job *job)
+bool job_cancel_requested(Job *job)
+{
+ JOB_LOCK_GUARD();
+ return job_cancel_requested_locked(job);
+}
+
+bool job_is_ready_locked(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_ready(Job *job)
+{
+ JOB_LOCK_GUARD();
+ return job_is_ready_locked(job);
+}
+
+bool job_is_completed_locked(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_is_completed(Job *job)
+{
+ JOB_LOCK_GUARD();
+ return job_is_completed_locked(job);
+}
+
+static bool job_started_locked(Job *job)
+{
+ return job->co;
+}
+
+/* Called with job_mutex held. */
+static bool job_should_pause_locked(Job *job)
+{
+ return job->pause_count > 0;
+}
+
+Job *job_next_locked(Job *job)
{
if (!job) {
return QLIST_FIRST(&jobs);
return QLIST_NEXT(job, job_list);
}
-Job *job_get(const char *id)
+Job *job_next(Job *job)
+{
+ JOB_LOCK_GUARD();
+ return job_next_locked(job);
+}
+
+Job *job_get_locked(const char *id)
{
Job *job;
return NULL;
}
-void *job_create(const char *job_id, const JobDriver *driver, AioContext *ctx,
- Error **errp)
+void job_set_aio_context(Job *job, AioContext *ctx)
+{
+ /* protect against read in job_finish_sync_locked and job_start */
+ GLOBAL_STATE_CODE();
+ /* protect against read in job_do_yield_locked */
+ JOB_LOCK_GUARD();
+ /* ensure the job is quiescent while the AioContext is changed */
+ assert(job->paused || job_is_completed_locked(job));
+ job->aio_context = ctx;
+}
+
+/* Called with job_mutex *not* held. */
+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;
+ JOB_LOCK_GUARD();
+
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)) {
+ if (job_get_locked(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->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;
- job_state_transition(job, JOB_STATUS_CREATED);
+ progress_init(&job->progress);
+
+ 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);
+ notifier_list_init(&job->on_idle);
+
+ job_state_transition_locked(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_locked(txn, job);
+ job_txn_unref_locked(txn);
+ } else {
+ job_txn_add_job_locked(txn, job);
+ }
+
return job;
}
-void job_ref(Job *job)
+void job_ref_locked(Job *job)
{
++job->refcnt;
}
-void job_unref(Job *job)
+void job_unref_locked(Job *job)
{
+ GLOBAL_STATE_CODE();
+
if (--job->refcnt == 0) {
assert(job->status == JOB_STATUS_NULL);
+ assert(!timer_pending(&job->sleep_timer));
+ assert(!job->txn);
if (job->driver->free) {
+ AioContext *aio_context = job->aio_context;
+ job_unlock();
+ /* FIXME: aiocontext lock is required because cb calls blk_unref */
+ aio_context_acquire(aio_context);
job->driver->free(job);
+ aio_context_release(aio_context);
+ job_lock();
}
QLIST_REMOVE(job, job_list);
+ progress_destroy(&job->progress);
+ error_free(job->err);
g_free(job->id);
g_free(job);
}
}
+
+void job_progress_update(Job *job, uint64_t done)
+{
+ progress_work_done(&job->progress, done);
+}
+
+void job_progress_set_remaining(Job *job, uint64_t remaining)
+{
+ progress_set_remaining(&job->progress, remaining);
+}
+
+void job_progress_increase_remaining(Job *job, uint64_t delta)
+{
+ progress_increase_remaining(&job->progress, delta);
+}
+
+/**
+ * To be called when a cancelled job is finalised.
+ * Called with job_mutex held.
+ */
+static void job_event_cancelled_locked(Job *job)
+{
+ notifier_list_notify(&job->on_finalize_cancelled, job);
+}
+
+/**
+ * To be called when a successfully completed job is finalised.
+ * Called with job_mutex held.
+ */
+static void job_event_completed_locked(Job *job)
+{
+ notifier_list_notify(&job->on_finalize_completed, job);
+}
+
+/* Called with job_mutex held. */
+static void job_event_pending_locked(Job *job)
+{
+ notifier_list_notify(&job->on_pending, job);
+}
+
+/* Called with job_mutex held. */
+static void job_event_ready_locked(Job *job)
+{
+ notifier_list_notify(&job->on_ready, job);
+}
+
+/* Called with job_mutex held. */
+static void job_event_idle_locked(Job *job)
+{
+ notifier_list_notify(&job->on_idle, job);
+}
+
+void job_enter_cond_locked(Job *job, bool(*fn)(Job *job))
+{
+ if (!job_started_locked(job)) {
+ return;
+ }
+ if (job->deferred_to_main_loop) {
+ return;
+ }
+
+ if (job->busy) {
+ return;
+ }
+
+ if (fn && !fn(job)) {
+ return;
+ }
+
+ assert(!job->deferred_to_main_loop);
+ timer_del(&job->sleep_timer);
+ job->busy = true;
+ job_unlock();
+ aio_co_wake(job->co);
+ job_lock();
+}
+
+void job_enter(Job *job)
+{
+ JOB_LOCK_GUARD();
+ job_enter_cond_locked(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.
+ *
+ * Called with job_mutex held, but releases it temporarily.
+ */
+static void coroutine_fn job_do_yield_locked(Job *job, uint64_t ns)
+{
+ AioContext *next_aio_context;
+
+ if (ns != -1) {
+ timer_mod(&job->sleep_timer, ns);
+ }
+ job->busy = false;
+ job_event_idle_locked(job);
+ job_unlock();
+ qemu_coroutine_yield();
+ job_lock();
+
+ next_aio_context = job->aio_context;
+ /*
+ * Coroutine has resumed, but in the meanwhile the job AioContext
+ * might have changed via bdrv_try_change_aio_context(), so we need to move
+ * the coroutine too in the new aiocontext.
+ */
+ while (qemu_get_current_aio_context() != next_aio_context) {
+ job_unlock();
+ aio_co_reschedule_self(next_aio_context);
+ job_lock();
+ next_aio_context = job->aio_context;
+ }
+
+ /* Set by job_enter_cond_locked() before re-entering the coroutine. */
+ assert(job->busy);
+}
+
+/* Called with job_mutex held, but releases it temporarily. */
+static void coroutine_fn job_pause_point_locked(Job *job)
+{
+ assert(job && job_started_locked(job));
+
+ if (!job_should_pause_locked(job)) {
+ return;
+ }
+ if (job_is_cancelled_locked(job)) {
+ return;
+ }
+
+ if (job->driver->pause) {
+ job_unlock();
+ job->driver->pause(job);
+ job_lock();
+ }
+
+ if (job_should_pause_locked(job) && !job_is_cancelled_locked(job)) {
+ JobStatus status = job->status;
+ job_state_transition_locked(job, status == JOB_STATUS_READY
+ ? JOB_STATUS_STANDBY
+ : JOB_STATUS_PAUSED);
+ job->paused = true;
+ job_do_yield_locked(job, -1);
+ job->paused = false;
+ job_state_transition_locked(job, status);
+ }
+
+ if (job->driver->resume) {
+ job_unlock();
+ job->driver->resume(job);
+ job_lock();
+ }
+}
+
+void coroutine_fn job_pause_point(Job *job)
+{
+ JOB_LOCK_GUARD();
+ job_pause_point_locked(job);
+}
+
+void coroutine_fn job_yield(Job *job)
+{
+ JOB_LOCK_GUARD();
+ assert(job->busy);
+
+ /* Check cancellation *before* setting busy = false, too! */
+ if (job_is_cancelled_locked(job)) {
+ return;
+ }
+
+ if (!job_should_pause_locked(job)) {
+ job_do_yield_locked(job, -1);
+ }
+
+ job_pause_point_locked(job);
+}
+
+void coroutine_fn job_sleep_ns(Job *job, int64_t ns)
+{
+ JOB_LOCK_GUARD();
+ assert(job->busy);
+
+ /* Check cancellation *before* setting busy = false, too! */
+ if (job_is_cancelled_locked(job)) {
+ return;
+ }
+
+ if (!job_should_pause_locked(job)) {
+ job_do_yield_locked(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + ns);
+ }
+
+ job_pause_point_locked(job);
+}
+
+/* Assumes the job_mutex is held */
+static bool job_timer_not_pending_locked(Job *job)
+{
+ return !timer_pending(&job->sleep_timer);
+}
+
+void job_pause_locked(Job *job)
+{
+ job->pause_count++;
+ if (!job->paused) {
+ job_enter_cond_locked(job, NULL);
+ }
+}
+
+void job_pause(Job *job)
+{
+ JOB_LOCK_GUARD();
+ job_pause_locked(job);
+}
+
+void job_resume_locked(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_locked(job, job_timer_not_pending_locked);
+}
+
+void job_resume(Job *job)
+{
+ JOB_LOCK_GUARD();
+ job_resume_locked(job);
+}
+
+void job_user_pause_locked(Job *job, Error **errp)
+{
+ if (job_apply_verb_locked(job, JOB_VERB_PAUSE, errp)) {
+ return;
+ }
+ if (job->user_paused) {
+ error_setg(errp, "Job is already paused");
+ return;
+ }
+ job->user_paused = true;
+ job_pause_locked(job);
+}
+
+bool job_user_paused_locked(Job *job)
+{
+ return job->user_paused;
+}
+
+void job_user_resume_locked(Job *job, Error **errp)
+{
+ assert(job);
+ GLOBAL_STATE_CODE();
+ 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_locked(job, JOB_VERB_RESUME, errp)) {
+ return;
+ }
+ if (job->driver->user_resume) {
+ job_unlock();
+ job->driver->user_resume(job);
+ job_lock();
+ }
+ job->user_paused = false;
+ job_resume_locked(job);
+}
+
+/* Called with job_mutex held, but releases it temporarily. */
+static void job_do_dismiss_locked(Job *job)
+{
+ assert(job);
+ job->busy = false;
+ job->paused = false;
+ job->deferred_to_main_loop = true;
+
+ job_txn_del_job_locked(job);
+
+ job_state_transition_locked(job, JOB_STATUS_NULL);
+ job_unref_locked(job);
+}
+
+void job_dismiss_locked(Job **jobptr, Error **errp)
+{
+ Job *job = *jobptr;
+ /* similarly to _complete, this is QMP-interface only. */
+ assert(job->id);
+ if (job_apply_verb_locked(job, JOB_VERB_DISMISS, errp)) {
+ return;
+ }
+
+ job_do_dismiss_locked(job);
+ *jobptr = NULL;
+}
+
+void job_early_fail(Job *job)
+{
+ JOB_LOCK_GUARD();
+ assert(job->status == JOB_STATUS_CREATED);
+ job_do_dismiss_locked(job);
+}
+
+/* Called with job_mutex held. */
+static void job_conclude_locked(Job *job)
+{
+ job_state_transition_locked(job, JOB_STATUS_CONCLUDED);
+ if (job->auto_dismiss || !job_started_locked(job)) {
+ job_do_dismiss_locked(job);
+ }
+}
+
+/* Called with job_mutex held. */
+static void job_update_rc_locked(Job *job)
+{
+ if (!job->ret && job_is_cancelled_locked(job)) {
+ job->ret = -ECANCELED;
+ }
+ if (job->ret) {
+ if (!job->err) {
+ error_setg(&job->err, "%s", strerror(-job->ret));
+ }
+ job_state_transition_locked(job, JOB_STATUS_ABORTING);
+ }
+}
+
+static void job_commit(Job *job)
+{
+ assert(!job->ret);
+ GLOBAL_STATE_CODE();
+ if (job->driver->commit) {
+ job->driver->commit(job);
+ }
+}
+
+static void job_abort(Job *job)
+{
+ assert(job->ret);
+ GLOBAL_STATE_CODE();
+ if (job->driver->abort) {
+ job->driver->abort(job);
+ }
+}
+
+static void job_clean(Job *job)
+{
+ GLOBAL_STATE_CODE();
+ if (job->driver->clean) {
+ job->driver->clean(job);
+ }
+}
+
+/*
+ * Called with job_mutex held, but releases it temporarily.
+ * Takes AioContext lock internally to invoke a job->driver callback.
+ */
+static int job_finalize_single_locked(Job *job)
+{
+ int job_ret;
+ AioContext *ctx = job->aio_context;
+
+ assert(job_is_completed_locked(job));
+
+ /* Ensure abort is called for late-transactional failures */
+ job_update_rc_locked(job);
+
+ job_ret = job->ret;
+ job_unlock();
+ aio_context_acquire(ctx);
+
+ if (!job_ret) {
+ job_commit(job);
+ } else {
+ job_abort(job);
+ }
+ job_clean(job);
+
+ if (job->cb) {
+ job->cb(job->opaque, job_ret);
+ }
+
+ aio_context_release(ctx);
+ job_lock();
+
+ /* Emit events only if we actually started */
+ if (job_started_locked(job)) {
+ if (job_is_cancelled_locked(job)) {
+ job_event_cancelled_locked(job);
+ } else {
+ job_event_completed_locked(job);
+ }
+ }
+
+ job_txn_del_job_locked(job);
+ job_conclude_locked(job);
+ return 0;
+}
+
+/*
+ * Called with job_mutex held, but releases it temporarily.
+ * Takes AioContext lock internally to invoke a job->driver callback.
+ */
+static void job_cancel_async_locked(Job *job, bool force)
+{
+ AioContext *ctx = job->aio_context;
+ GLOBAL_STATE_CODE();
+ if (job->driver->cancel) {
+ job_unlock();
+ aio_context_acquire(ctx);
+ force = job->driver->cancel(job, force);
+ aio_context_release(ctx);
+ job_lock();
+ } else {
+ /* No .cancel() means the job will behave as if force-cancelled */
+ force = true;
+ }
+
+ if (job->user_paused) {
+ /* Do not call job_enter here, the caller will handle it. */
+ if (job->driver->user_resume) {
+ job_unlock();
+ job->driver->user_resume(job);
+ job_lock();
+ }
+ job->user_paused = false;
+ assert(job->pause_count > 0);
+ job->pause_count--;
+ }
+
+ /*
+ * Ignore soft cancel requests after the job is already done
+ * (We will still invoke job->driver->cancel() above, but if the
+ * job driver supports soft cancelling and the job is done, that
+ * should be a no-op, too. We still call it so it can override
+ * @force.)
+ */
+ if (force || !job->deferred_to_main_loop) {
+ job->cancelled = true;
+ /* To prevent 'force == false' overriding a previous 'force == true' */
+ job->force_cancel |= force;
+ }
+}
+
+/*
+ * Called with job_mutex held, but releases it temporarily.
+ * Takes AioContext lock internally to invoke a job->driver callback.
+ */
+static void job_completed_txn_abort_locked(Job *job)
+{
+ 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_locked(txn);
+
+ job_ref_locked(job);
+
+ /* 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) {
+ /*
+ * This is a transaction: If one job failed, no result will matter.
+ * Therefore, pass force=true to terminate all other jobs as quickly
+ * as possible.
+ */
+ job_cancel_async_locked(other_job, true);
+ }
+ }
+ while (!QLIST_EMPTY(&txn->jobs)) {
+ other_job = QLIST_FIRST(&txn->jobs);
+ if (!job_is_completed_locked(other_job)) {
+ assert(job_cancel_requested_locked(other_job));
+ job_finish_sync_locked(other_job, NULL, NULL);
+ }
+ job_finalize_single_locked(other_job);
+ }
+
+ job_unref_locked(job);
+ job_txn_unref_locked(txn);
+}
+
+/* Called with job_mutex held, but releases it temporarily */
+static int job_prepare_locked(Job *job)
+{
+ int ret;
+ AioContext *ctx = job->aio_context;
+
+ GLOBAL_STATE_CODE();
+
+ if (job->ret == 0 && job->driver->prepare) {
+ job_unlock();
+ aio_context_acquire(ctx);
+ ret = job->driver->prepare(job);
+ aio_context_release(ctx);
+ job_lock();
+ job->ret = ret;
+ job_update_rc_locked(job);
+ }
+
+ return job->ret;
+}
+
+/* Called with job_mutex held */
+static int job_needs_finalize_locked(Job *job)
+{
+ return !job->auto_finalize;
+}
+
+/* Called with job_mutex held */
+static void job_do_finalize_locked(Job *job)
+{
+ int rc;
+ assert(job && job->txn);
+
+ /* prepare the transaction to complete */
+ rc = job_txn_apply_locked(job, job_prepare_locked);
+ if (rc) {
+ job_completed_txn_abort_locked(job);
+ } else {
+ job_txn_apply_locked(job, job_finalize_single_locked);
+ }
+}
+
+void job_finalize_locked(Job *job, Error **errp)
+{
+ assert(job && job->id);
+ if (job_apply_verb_locked(job, JOB_VERB_FINALIZE, errp)) {
+ return;
+ }
+ job_do_finalize_locked(job);
+}
+
+/* Called with job_mutex held. */
+static int job_transition_to_pending_locked(Job *job)
+{
+ job_state_transition_locked(job, JOB_STATUS_PENDING);
+ if (!job->auto_finalize) {
+ job_event_pending_locked(job);
+ }
+ return 0;
+}
+
+void job_transition_to_ready(Job *job)
+{
+ JOB_LOCK_GUARD();
+ job_state_transition_locked(job, JOB_STATUS_READY);
+ job_event_ready_locked(job);
+}
+
+/* Called with job_mutex held. */
+static void job_completed_txn_success_locked(Job *job)
+{
+ JobTxn *txn = job->txn;
+ Job *other_job;
+
+ job_state_transition_locked(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_locked(other_job)) {
+ return;
+ }
+ assert(other_job->ret == 0);
+ }
+
+ job_txn_apply_locked(job, job_transition_to_pending_locked);
+
+ /* If no jobs need manual finalization, automatically do so */
+ if (job_txn_apply_locked(job, job_needs_finalize_locked) == 0) {
+ job_do_finalize_locked(job);
+ }
+}
+
+/* Called with job_mutex held. */
+static void job_completed_locked(Job *job)
+{
+ assert(job && job->txn && !job_is_completed_locked(job));
+
+ job_update_rc_locked(job);
+ trace_job_completed(job, job->ret);
+ if (job->ret) {
+ job_completed_txn_abort_locked(job);
+ } else {
+ job_completed_txn_success_locked(job);
+ }
+}
+
+/**
+ * Useful only as a type shim for aio_bh_schedule_oneshot.
+ * Called with job_mutex *not* held.
+ */
+static void job_exit(void *opaque)
+{
+ Job *job = (Job *)opaque;
+ JOB_LOCK_GUARD();
+ job_ref_locked(job);
+
+ /* This is a lie, we're not quiescent, but still doing the completion
+ * callbacks. However, completion callbacks tend to involve operations that
+ * drain block nodes, and if .drained_poll still returned true, we would
+ * deadlock. */
+ job->busy = false;
+ job_event_idle_locked(job);
+
+ job_completed_locked(job);
+ job_unref_locked(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;
+ int ret;
+
+ assert(job && job->driver && job->driver->run);
+ WITH_JOB_LOCK_GUARD() {
+ assert(job->aio_context == qemu_get_current_aio_context());
+ job_pause_point_locked(job);
+ }
+ ret = job->driver->run(job, &job->err);
+ WITH_JOB_LOCK_GUARD() {
+ job->ret = ret;
+ job->deferred_to_main_loop = true;
+ job->busy = true;
+ }
+ aio_bh_schedule_oneshot(qemu_get_aio_context(), job_exit, job);
+}
+
+void job_start(Job *job)
+{
+ assert(qemu_in_main_thread());
+
+ WITH_JOB_LOCK_GUARD() {
+ assert(job && !job_started_locked(job) && job->paused &&
+ job->driver && job->driver->run);
+ job->co = qemu_coroutine_create(job_co_entry, job);
+ job->pause_count--;
+ job->busy = true;
+ job->paused = false;
+ job_state_transition_locked(job, JOB_STATUS_RUNNING);
+ }
+ aio_co_enter(job->aio_context, job->co);
+}
+
+void job_cancel_locked(Job *job, bool force)
+{
+ if (job->status == JOB_STATUS_CONCLUDED) {
+ job_do_dismiss_locked(job);
+ return;
+ }
+ job_cancel_async_locked(job, force);
+ if (!job_started_locked(job)) {
+ job_completed_locked(job);
+ } else if (job->deferred_to_main_loop) {
+ /*
+ * job_cancel_async() ignores soft-cancel requests for jobs
+ * that are already done (i.e. deferred to the main loop). We
+ * have to check again whether the job is really cancelled.
+ * (job_cancel_requested() and job_is_cancelled() are equivalent
+ * here, because job_cancel_async() will make soft-cancel
+ * requests no-ops when deferred_to_main_loop is true. We
+ * choose to call job_is_cancelled() to show that we invoke
+ * job_completed_txn_abort() only for force-cancelled jobs.)
+ */
+ if (job_is_cancelled_locked(job)) {
+ job_completed_txn_abort_locked(job);
+ }
+ } else {
+ job_enter_cond_locked(job, NULL);
+ }
+}
+
+void job_user_cancel_locked(Job *job, bool force, Error **errp)
+{
+ if (job_apply_verb_locked(job, JOB_VERB_CANCEL, errp)) {
+ return;
+ }
+ job_cancel_locked(job, force);
+}
+
+/* A wrapper around job_cancel_locked() taking an Error ** parameter so it may
+ * be used with job_finish_sync_locked() without the need for (rather nasty)
+ * function pointer casts there.
+ *
+ * Called with job_mutex held.
+ */
+static void job_cancel_err_locked(Job *job, Error **errp)
+{
+ job_cancel_locked(job, false);
+}
+
+/**
+ * Same as job_cancel_err(), but force-cancel.
+ * Called with job_mutex held.
+ */
+static void job_force_cancel_err_locked(Job *job, Error **errp)
+{
+ job_cancel_locked(job, true);
+}
+
+int job_cancel_sync_locked(Job *job, bool force)
+{
+ if (force) {
+ return job_finish_sync_locked(job, &job_force_cancel_err_locked, NULL);
+ } else {
+ return job_finish_sync_locked(job, &job_cancel_err_locked, NULL);
+ }
+}
+
+int job_cancel_sync(Job *job, bool force)
+{
+ JOB_LOCK_GUARD();
+ return job_cancel_sync_locked(job, force);
+}
+
+void job_cancel_sync_all(void)
+{
+ Job *job;
+ JOB_LOCK_GUARD();
+
+ while ((job = job_next_locked(NULL))) {
+ job_cancel_sync_locked(job, true);
+ }
+}
+
+int job_complete_sync_locked(Job *job, Error **errp)
+{
+ return job_finish_sync_locked(job, job_complete_locked, errp);
+}
+
+void job_complete_locked(Job *job, Error **errp)
+{
+ /* Should not be reachable via external interface for internal jobs */
+ assert(job->id);
+ GLOBAL_STATE_CODE();
+ if (job_apply_verb_locked(job, JOB_VERB_COMPLETE, errp)) {
+ return;
+ }
+ if (job_cancel_requested_locked(job) || !job->driver->complete) {
+ error_setg(errp, "The active block job '%s' cannot be completed",
+ job->id);
+ return;
+ }
+
+ job_unlock();
+ job->driver->complete(job, errp);
+ job_lock();
+}
+
+int job_finish_sync_locked(Job *job,
+ void (*finish)(Job *, Error **errp),
+ Error **errp)
+{
+ Error *local_err = NULL;
+ int ret;
+ GLOBAL_STATE_CODE();
+
+ job_ref_locked(job);
+
+ if (finish) {
+ finish(job, &local_err);
+ }
+ if (local_err) {
+ error_propagate(errp, local_err);
+ job_unref_locked(job);
+ return -EBUSY;
+ }
+
+ job_unlock();
+ AIO_WAIT_WHILE_UNLOCKED(job->aio_context,
+ (job_enter(job), !job_is_completed(job)));
+ job_lock();
+
+ ret = (job_is_cancelled_locked(job) && job->ret == 0)
+ ? -ECANCELED : job->ret;
+ job_unref_locked(job);
+ return ret;
+}
projects / mirror_qemu.git / blobdiff