qemu/blockjob.c
Emanuele Giuseppe Esposito 880eeec613 jobs: group together API calls under the same job lock
Now that the API offers also _locked() functions, take advantage
of it and give also the caller control to take the lock and call
_locked functions.

This makes sense especially when we have for loops, because it
makes no sense to have:

for(job = job_next(); ...)

where each job_next() takes the lock internally.
Instead we want

JOB_LOCK_GUARD();
for(job = job_next_locked(); ...)

In addition, protect also direct field accesses, by either creating a
new critical section or widening the existing ones.

Note: at this stage, job_{lock/unlock} and job lock guard macros
are *nop*.

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

585 lines
16 KiB
C

/*
* 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"
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_locked(BlockJob *bjob)
{
Job *job = bjob ? &bjob->job : NULL;
GLOBAL_STATE_CODE();
do {
job = job_next_locked(job);
} while (job && !is_block_job(job));
return job ? container_of(job, BlockJob, job) : NULL;
}
BlockJob *block_job_next(BlockJob *bjob)
{
JOB_LOCK_GUARD();
return block_job_next_locked(bjob);
}
BlockJob *block_job_get_locked(const char *id)
{
Job *job = job_get_locked(id);
GLOBAL_STATE_CODE();
if (job && is_block_job(job)) {
return container_of(job, BlockJob, job);
} else {
return NULL;
}
}
BlockJob *block_job_get(const char *id)
{
JOB_LOCK_GUARD();
return block_job_get_locked(id);
}
void block_job_free(Job *job)
{
BlockJob *bjob = container_of(job, BlockJob, job);
GLOBAL_STATE_CODE();
block_job_remove_all_bdrv(bjob);
ratelimit_destroy(&bjob->limit);
error_free(bjob->blocker);
}
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. */
WITH_JOB_LOCK_GUARD() {
if (!job->busy || job_is_completed_locked(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 AioContext *child_job_get_parent_aio_context(BdrvChild *c)
{
BlockJob *job = c->opaque;
return job->job.aio_context;
}
static const BdrvChildClass 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,
.get_parent_aio_context = child_job_get_parent_aio_context,
};
void block_job_remove_all_bdrv(BlockJob *job)
{
GLOBAL_STATE_CODE();
/*
* bdrv_root_unref_child() may reach child_job_[can_]set_aio_ctx(),
* which will also traverse job->nodes, so consume the list one by
* one to make sure that such a concurrent access does not attempt
* to process an already freed BdrvChild.
*/
while (job->nodes) {
GSList *l = job->nodes;
BdrvChild *c = l->data;
job->nodes = l->next;
bdrv_op_unblock_all(c->bs, job->blocker);
bdrv_root_unref_child(c);
g_slist_free_1(l);
}
}
bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs)
{
GSList *el;
GLOBAL_STATE_CODE();
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;
bool need_context_ops;
GLOBAL_STATE_CODE();
bdrv_ref(bs);
need_context_ops = bdrv_get_aio_context(bs) != job->job.aio_context;
if (need_context_ops && job->job.aio_context != qemu_get_aio_context()) {
aio_context_release(job->job.aio_context);
}
c = bdrv_root_attach_child(bs, name, &child_job, 0, perm, shared_perm, job,
errp);
if (need_context_ops && 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);
}
bool block_job_set_speed_locked(BlockJob *job, int64_t speed, Error **errp)
{
const BlockJobDriver *drv = block_job_driver(job);
int64_t old_speed = job->speed;
GLOBAL_STATE_CODE();
if (job_apply_verb_locked(&job->job, JOB_VERB_SET_SPEED, errp) < 0) {
return false;
}
if (speed < 0) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "speed",
"a non-negative value");
return false;
}
ratelimit_set_speed(&job->limit, speed, BLOCK_JOB_SLICE_TIME);
job->speed = speed;
if (drv->set_speed) {
job_unlock();
drv->set_speed(job, speed);
job_lock();
}
if (speed && speed <= old_speed) {
return true;
}
/* kick only if a timer is pending */
job_enter_cond_locked(&job->job, job_timer_pending);
return true;
}
bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
{
JOB_LOCK_GUARD();
return block_job_set_speed_locked(job, speed, errp);
}
int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n)
{
IO_CODE();
return ratelimit_calculate_delay(&job->limit, n);
}
BlockJobInfo *block_job_query_locked(BlockJob *job, Error **errp)
{
BlockJobInfo *info;
uint64_t progress_current, progress_total;
GLOBAL_STATE_CODE();
if (block_job_is_internal(job)) {
error_setg(errp, "Cannot query QEMU internal jobs");
return NULL;
}
progress_get_snapshot(&job->job.progress, &progress_current,
&progress_total);
info = g_new0(BlockJobInfo, 1);
info->type = g_strdup(job_type_str(&job->job));
info->device = g_strdup(job->job.id);
info->busy = qatomic_read(&job->job.busy);
info->paused = job->job.pause_count > 0;
info->offset = progress_current;
info->len = progress_total;
info->speed = job->speed;
info->io_status = job->iostatus;
info->ready = job_is_ready_locked(&job->job),
info->status = job->job.status;
info->auto_finalize = job->job.auto_finalize;
info->auto_dismiss = job->job.auto_dismiss;
if (job->job.ret) {
info->has_error = true;
info->error = job->job.err ?
g_strdup(error_get_pretty(job->job.err)) :
g_strdup(strerror(-job->job.ret));
}
return info;
}
BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
{
JOB_LOCK_GUARD();
return block_job_query_locked(job, errp);
}
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;
uint64_t progress_current, progress_total;
if (block_job_is_internal(job)) {
return;
}
progress_get_snapshot(&job->job.progress, &progress_current,
&progress_total);
qapi_event_send_block_job_cancelled(job_type(&job->job),
job->job.id,
progress_total,
progress_current,
job->speed);
}
static void block_job_event_completed(Notifier *n, void *opaque)
{
BlockJob *job = opaque;
const char *msg = NULL;
uint64_t progress_current, progress_total;
if (block_job_is_internal(job)) {
return;
}
if (job->job.ret < 0) {
msg = error_get_pretty(job->job.err);
}
progress_get_snapshot(&job->job.progress, &progress_current,
&progress_total);
qapi_event_send_block_job_completed(job_type(&job->job),
job->job.id,
progress_total,
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;
uint64_t progress_current, progress_total;
if (block_job_is_internal(job)) {
return;
}
progress_get_snapshot(&job->job.progress, &progress_current,
&progress_total);
qapi_event_send_block_job_ready(job_type(&job->job),
job->job.id,
progress_total,
progress_current,
job->speed);
}
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)
{
BlockJob *job;
int ret;
GLOBAL_STATE_CODE();
if (job_id == NULL && !(flags & JOB_INTERNAL)) {
job_id = bdrv_get_device_name(bs);
}
job = job_create(job_id, &driver->job_driver, txn, bdrv_get_aio_context(bs),
flags, cb, opaque, errp);
if (job == NULL) {
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);
ratelimit_init(&job->limit);
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;
WITH_JOB_LOCK_GUARD() {
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));
ret = block_job_add_bdrv(job, "main node", bs, perm, shared_perm, errp);
if (ret < 0) {
goto fail;
}
bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
if (!block_job_set_speed(job, speed, errp)) {
goto fail;
}
return job;
fail:
job_early_fail(&job->job);
return NULL;
}
void block_job_iostatus_reset_locked(BlockJob *job)
{
GLOBAL_STATE_CODE();
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_iostatus_reset(BlockJob *job)
{
JOB_LOCK_GUARD();
block_job_iostatus_reset_locked(job);
}
void block_job_user_resume(Job *job)
{
BlockJob *bjob = container_of(job, BlockJob, job);
GLOBAL_STATE_CODE();
block_job_iostatus_reset(bjob);
}
BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
int is_read, int error)
{
BlockErrorAction action;
IO_CODE();
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) {
WITH_JOB_LOCK_GUARD() {
if (!job->job.user_paused) {
job_pause_locked(&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;
}
AioContext *block_job_get_aio_context(BlockJob *job)
{
GLOBAL_STATE_CODE();
return job->job.aio_context;
}