qemu/blockjob.c
Emanuele Giuseppe Esposito a7b4f8fc09 progressmeter: protect with a mutex
Progressmeter is protected by the AioContext mutex, which
is taken by the block jobs and their caller (like blockdev).

We would like to remove the dependency of block layer code on the
AioContext mutex, since most drivers and the core I/O code are already
not relying on it.

Create a new C file to implement the ProgressMeter API, but keep the
struct as public, to avoid forcing allocation on the heap.

Also add a mutex to be able to provide an accurate snapshot of the
progress values to the caller.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20210614081130.22134-5-eesposit@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-06-25 14:24:24 +03:00

550 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"
/*
* 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);
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. */
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 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)
{
/*
* 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;
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;
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(BlockJob *job, int64_t speed, Error **errp)
{
const BlockJobDriver *drv = block_job_driver(job);
int64_t old_speed = job->speed;
if (job_apply_verb(&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) {
drv->set_speed(job, speed);
}
if (speed && speed <= old_speed) {
return true;
}
/* kick only if a timer is pending */
job_enter_cond(&job->job, job_timer_pending);
return true;
}
int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n)
{
return ratelimit_calculate_delay(&job->limit, n);
}
BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
{
BlockJobInfo *info;
uint64_t progress_current, progress_total;
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(&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;
}
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);
}
/*
* 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;
if (job_id == NULL && !(flags & JOB_INTERNAL)) {
job_id = bdrv_get_device_name(bs);
}
blk = blk_new_with_bs(bs, perm, shared_perm, errp);
if (!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);
ratelimit_init(&job->limit);
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);
/* Disable request queuing in the BlockBackend to avoid deadlocks on drain:
* The job reports that it's busy until it reaches a pause point. */
blk_set_disable_request_queuing(blk, true);
blk_set_allow_aio_context_change(blk, true);
if (!block_job_set_speed(job, speed, errp)) {
job_early_fail(&job->job);
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;
}