qemu/blockjob.c
Kevin Wolf 132ada80c4 block: Adjust AioContexts when attaching nodes
So far, we only made sure that updating the AioContext of a node
affected the whole subtree. However, if a node is newly attached to a
new parent, we also need to make sure that both the subtree of the node
and the parent are in the same AioContext. This tries to move the new
child node to the parent AioContext and returns an error if this isn't
possible.

BlockBackends now actually apply their AioContext to their root node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 15:22:22 +02:00

514 lines
15 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 "qemu-common.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/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);
BlockDriverState *bs = blk_bs(bjob->blk);
bs->job = NULL;
block_job_remove_all_bdrv(bjob);
blk_unref(bjob->blk);
error_free(bjob->blocker);
}
void block_job_drain(Job *job)
{
BlockJob *bjob = container_of(job, BlockJob, job);
const JobDriver *drv = job->driver;
BlockJobDriver *bjdrv = container_of(drv, BlockJobDriver, job_driver);
blk_drain(bjob->blk);
if (bjdrv->drain) {
bjdrv->drain(bjob);
}
}
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)
{
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 const BdrvChildRole 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,
};
void block_job_remove_all_bdrv(BlockJob *job)
{
GSList *l;
for (l = job->nodes; l; l = l->next) {
BdrvChild *c = l->data;
bdrv_op_unblock_all(c->bs, job->blocker);
bdrv_root_unref_child(c);
}
g_slist_free(job->nodes);
job->nodes = NULL;
}
int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
uint64_t perm, uint64_t shared_perm, Error **errp)
{
BdrvChild *c;
bdrv_ref(bs);
if (job->job.aio_context != qemu_get_aio_context()) {
aio_context_release(job->job.aio_context);
}
c = bdrv_root_attach_child(bs, name, &child_job, job->job.aio_context,
perm, shared_perm, job, errp);
if (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);
}
void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
{
int64_t old_speed = job->speed;
if (job_apply_verb(&job->job, JOB_VERB_SET_SPEED, errp)) {
return;
}
if (speed < 0) {
error_setg(errp, QERR_INVALID_PARAMETER, "speed");
return;
}
ratelimit_set_speed(&job->limit, speed, BLOCK_JOB_SLICE_TIME);
job->speed = speed;
if (speed && speed <= old_speed) {
return;
}
/* kick only if a timer is pending */
job_enter_cond(&job->job, job_timer_pending);
}
int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n)
{
if (!job->speed) {
return 0;
}
return ratelimit_calculate_delay(&job->limit, n);
}
BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
{
BlockJobInfo *info;
if (block_job_is_internal(job)) {
error_setg(errp, "Cannot query QEMU internal jobs");
return NULL;
}
info = g_new0(BlockJobInfo, 1);
info->type = g_strdup(job_type_str(&job->job));
info->device = g_strdup(job->job.id);
info->busy = atomic_read(&job->job.busy);
info->paused = job->job.pause_count > 0;
info->offset = job->job.progress_current;
info->len = job->job.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;
info->has_error = job->job.ret != 0;
info->error = job->job.ret ? g_strdup(strerror(-job->job.ret)) : NULL;
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;
if (block_job_is_internal(job)) {
return;
}
qapi_event_send_block_job_cancelled(job_type(&job->job),
job->job.id,
job->job.progress_total,
job->job.progress_current,
job->speed);
}
static void block_job_event_completed(Notifier *n, void *opaque)
{
BlockJob *job = opaque;
const char *msg = NULL;
if (block_job_is_internal(job)) {
return;
}
if (job->job.ret < 0) {
msg = strerror(-job->job.ret);
}
qapi_event_send_block_job_completed(job_type(&job->job),
job->job.id,
job->job.progress_total,
job->job.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;
if (block_job_is_internal(job)) {
return;
}
qapi_event_send_block_job_ready(job_type(&job->job),
job->job.id,
job->job.progress_total,
job->job.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;
int ret;
if (bs->job) {
error_setg(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
return NULL;
}
if (job_id == NULL && !(flags & JOB_INTERNAL)) {
job_id = bdrv_get_device_name(bs);
}
blk = blk_new(bdrv_get_aio_context(bs), perm, shared_perm);
ret = blk_insert_bs(blk, bs, errp);
if (ret < 0) {
blk_unref(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);
assert(job->job.driver->drain == &block_job_drain);
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);
bs->job = job;
bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
blk_set_allow_aio_context_change(blk, true);
/* Only set speed when necessary to avoid NotSupported error */
if (speed != 0) {
Error *local_err = NULL;
block_job_set_speed(job, speed, &local_err);
if (local_err) {
job_early_fail(&job->job);
error_propagate(errp, local_err);
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;
}