qemu/job-qmp.c
Emanuele Giuseppe Esposito 6f592e5aca job.c: enable job lock/unlock and remove Aiocontext locks
Change the job_{lock/unlock} and macros to use job_mutex.

Now that they are not nop anymore, remove the aiocontext
to avoid deadlocks.

Therefore:
- when possible, remove completely the aiocontext lock/unlock pair
- if it is used by some other function too, reduce the locking
  section as much as possible, leaving the job API outside.
- change AIO_WAIT_WHILE in AIO_WAIT_WHILE_UNLOCKED, since we
  are not using the aiocontext lock anymore

The only functions that still need the aiocontext lock are:
- the JobDriver callbacks, already documented in job.h
- job_cancel_sync() in replication.c is called with aio_context_lock
  taken, but now job is using AIO_WAIT_WHILE_UNLOCKED so we need to
  release the lock.

Reduce the locking section to only cover the callback invocation
and document the functions that take the AioContext lock,
to avoid taking it twice.

Also remove real_job_{lock/unlock}, as they are replaced by the
public functions.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20220926093214.506243-19-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-07 12:11:41 +02:00

190 lines
4.3 KiB
C

/*
* QMP interface for background jobs
*
* 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/job.h"
#include "qapi/qapi-commands-job.h"
#include "qapi/error.h"
#include "trace/trace-root.h"
/*
* Get a job using its ID. Called with job_mutex held.
*/
static Job *find_job_locked(const char *id, Error **errp)
{
Job *job;
job = job_get_locked(id);
if (!job) {
error_setg(errp, "Job not found");
return NULL;
}
return job;
}
void qmp_job_cancel(const char *id, Error **errp)
{
Job *job;
JOB_LOCK_GUARD();
job = find_job_locked(id, errp);
if (!job) {
return;
}
trace_qmp_job_cancel(job);
job_user_cancel_locked(job, true, errp);
}
void qmp_job_pause(const char *id, Error **errp)
{
Job *job;
JOB_LOCK_GUARD();
job = find_job_locked(id, errp);
if (!job) {
return;
}
trace_qmp_job_pause(job);
job_user_pause_locked(job, errp);
}
void qmp_job_resume(const char *id, Error **errp)
{
Job *job;
JOB_LOCK_GUARD();
job = find_job_locked(id, errp);
if (!job) {
return;
}
trace_qmp_job_resume(job);
job_user_resume_locked(job, errp);
}
void qmp_job_complete(const char *id, Error **errp)
{
Job *job;
JOB_LOCK_GUARD();
job = find_job_locked(id, errp);
if (!job) {
return;
}
trace_qmp_job_complete(job);
job_complete_locked(job, errp);
}
void qmp_job_finalize(const char *id, Error **errp)
{
Job *job;
JOB_LOCK_GUARD();
job = find_job_locked(id, errp);
if (!job) {
return;
}
trace_qmp_job_finalize(job);
job_ref_locked(job);
job_finalize_locked(job, errp);
job_unref_locked(job);
}
void qmp_job_dismiss(const char *id, Error **errp)
{
Job *job;
JOB_LOCK_GUARD();
job = find_job_locked(id, errp);
if (!job) {
return;
}
trace_qmp_job_dismiss(job);
job_dismiss_locked(&job, errp);
}
/* Called with job_mutex held. */
static JobInfo *job_query_single_locked(Job *job, Error **errp)
{
JobInfo *info;
uint64_t progress_current;
uint64_t progress_total;
assert(!job_is_internal(job));
progress_get_snapshot(&job->progress, &progress_current,
&progress_total);
info = g_new(JobInfo, 1);
*info = (JobInfo) {
.id = g_strdup(job->id),
.type = job_type(job),
.status = job->status,
.current_progress = progress_current,
.total_progress = progress_total,
.has_error = !!job->err,
.error = job->err ? \
g_strdup(error_get_pretty(job->err)) : NULL,
};
return info;
}
JobInfoList *qmp_query_jobs(Error **errp)
{
JobInfoList *head = NULL, **tail = &head;
Job *job;
JOB_LOCK_GUARD();
for (job = job_next_locked(NULL); job; job = job_next_locked(job)) {
JobInfo *value;
if (job_is_internal(job)) {
continue;
}
value = job_query_single_locked(job, errp);
if (!value) {
qapi_free_JobInfoList(head);
return NULL;
}
QAPI_LIST_APPEND(tail, value);
}
return head;
}