| /* |
| * 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 "trace.h" |
| #include "block/block.h" |
| #include "block/blockjob.h" |
| #include "block/block_int.h" |
| #include "sysemu/block-backend.h" |
| #include "qapi/qmp/qerror.h" |
| #include "qapi/qmp/qjson.h" |
| #include "qemu/coroutine.h" |
| #include "qemu/id.h" |
| #include "qmp-commands.h" |
| #include "qemu/timer.h" |
| #include "qapi-event.h" |
| |
| /* Transactional group of block jobs */ |
| struct BlockJobTxn { |
| |
| /* Is this txn being cancelled? */ |
| bool aborting; |
| |
| /* List of jobs */ |
| QLIST_HEAD(, BlockJob) jobs; |
| |
| /* Reference count */ |
| int refcnt; |
| }; |
| |
| static QLIST_HEAD(, BlockJob) block_jobs = QLIST_HEAD_INITIALIZER(block_jobs); |
| |
| BlockJob *block_job_next(BlockJob *job) |
| { |
| if (!job) { |
| return QLIST_FIRST(&block_jobs); |
| } |
| return QLIST_NEXT(job, job_list); |
| } |
| |
| BlockJob *block_job_get(const char *id) |
| { |
| BlockJob *job; |
| |
| QLIST_FOREACH(job, &block_jobs, job_list) { |
| if (!strcmp(id, job->id)) { |
| return job; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| /* Normally the job runs in its BlockBackend's AioContext. The exception is |
| * block_job_defer_to_main_loop() where it runs in the QEMU main loop. Code |
| * that supports both cases uses this helper function. |
| */ |
| static AioContext *block_job_get_aio_context(BlockJob *job) |
| { |
| return job->deferred_to_main_loop ? |
| qemu_get_aio_context() : |
| blk_get_aio_context(job->blk); |
| } |
| |
| static void block_job_attached_aio_context(AioContext *new_context, |
| void *opaque) |
| { |
| BlockJob *job = opaque; |
| |
| if (job->driver->attached_aio_context) { |
| job->driver->attached_aio_context(job, new_context); |
| } |
| |
| block_job_resume(job); |
| } |
| |
| static void block_job_detach_aio_context(void *opaque) |
| { |
| BlockJob *job = opaque; |
| |
| /* In case the job terminates during aio_poll()... */ |
| block_job_ref(job); |
| |
| block_job_pause(job); |
| |
| if (!job->paused) { |
| /* If job is !job->busy this kicks it into the next pause point. */ |
| block_job_enter(job); |
| } |
| while (!job->paused && !job->completed) { |
| aio_poll(block_job_get_aio_context(job), true); |
| } |
| |
| block_job_unref(job); |
| } |
| |
| void *block_job_create(const char *job_id, const BlockJobDriver *driver, |
| BlockDriverState *bs, int64_t speed, |
| BlockCompletionFunc *cb, void *opaque, Error **errp) |
| { |
| BlockBackend *blk; |
| BlockJob *job; |
| |
| assert(cb); |
| if (bs->job) { |
| error_setg(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs)); |
| return NULL; |
| } |
| |
| if (job_id == NULL) { |
| job_id = bdrv_get_device_name(bs); |
| if (!*job_id) { |
| error_setg(errp, "An explicit job ID is required for this node"); |
| return NULL; |
| } |
| } |
| |
| if (!id_wellformed(job_id)) { |
| error_setg(errp, "Invalid job ID '%s'", job_id); |
| return NULL; |
| } |
| |
| if (block_job_get(job_id)) { |
| error_setg(errp, "Job ID '%s' already in use", job_id); |
| return NULL; |
| } |
| |
| blk = blk_new(); |
| blk_insert_bs(blk, bs); |
| |
| job = g_malloc0(driver->instance_size); |
| error_setg(&job->blocker, "block device is in use by block job: %s", |
| BlockJobType_lookup[driver->job_type]); |
| bdrv_op_block_all(bs, job->blocker); |
| bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker); |
| |
| job->driver = driver; |
| job->id = g_strdup(job_id); |
| job->blk = blk; |
| job->cb = cb; |
| job->opaque = opaque; |
| job->busy = true; |
| job->refcnt = 1; |
| bs->job = job; |
| |
| QLIST_INSERT_HEAD(&block_jobs, job, job_list); |
| |
| blk_add_aio_context_notifier(blk, block_job_attached_aio_context, |
| block_job_detach_aio_context, job); |
| |
| /* 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) { |
| block_job_unref(job); |
| error_propagate(errp, local_err); |
| return NULL; |
| } |
| } |
| return job; |
| } |
| |
| void block_job_ref(BlockJob *job) |
| { |
| ++job->refcnt; |
| } |
| |
| void block_job_unref(BlockJob *job) |
| { |
| if (--job->refcnt == 0) { |
| BlockDriverState *bs = blk_bs(job->blk); |
| bs->job = NULL; |
| bdrv_op_unblock_all(bs, job->blocker); |
| blk_remove_aio_context_notifier(job->blk, |
| block_job_attached_aio_context, |
| block_job_detach_aio_context, job); |
| blk_unref(job->blk); |
| error_free(job->blocker); |
| g_free(job->id); |
| QLIST_REMOVE(job, job_list); |
| g_free(job); |
| } |
| } |
| |
| static void block_job_completed_single(BlockJob *job) |
| { |
| if (!job->ret) { |
| if (job->driver->commit) { |
| job->driver->commit(job); |
| } |
| } else { |
| if (job->driver->abort) { |
| job->driver->abort(job); |
| } |
| } |
| job->cb(job->opaque, job->ret); |
| if (job->txn) { |
| block_job_txn_unref(job->txn); |
| } |
| block_job_unref(job); |
| } |
| |
| static void block_job_completed_txn_abort(BlockJob *job) |
| { |
| AioContext *ctx; |
| BlockJobTxn *txn = job->txn; |
| BlockJob *other_job, *next; |
| |
| if (txn->aborting) { |
| /* |
| * We are cancelled by another job, which will handle everything. |
| */ |
| return; |
| } |
| txn->aborting = true; |
| /* We are the first failed job. Cancel other jobs. */ |
| QLIST_FOREACH(other_job, &txn->jobs, txn_list) { |
| ctx = blk_get_aio_context(other_job->blk); |
| aio_context_acquire(ctx); |
| } |
| QLIST_FOREACH(other_job, &txn->jobs, txn_list) { |
| if (other_job == job || other_job->completed) { |
| /* 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. */ |
| if (other_job != job) { |
| other_job->cancelled = true; |
| } |
| continue; |
| } |
| block_job_cancel_sync(other_job); |
| assert(other_job->completed); |
| } |
| QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) { |
| ctx = blk_get_aio_context(other_job->blk); |
| block_job_completed_single(other_job); |
| aio_context_release(ctx); |
| } |
| } |
| |
| static void block_job_completed_txn_success(BlockJob *job) |
| { |
| AioContext *ctx; |
| BlockJobTxn *txn = job->txn; |
| BlockJob *other_job, *next; |
| /* |
| * Successful completion, see if there are other running jobs in this |
| * txn. |
| */ |
| QLIST_FOREACH(other_job, &txn->jobs, txn_list) { |
| if (!other_job->completed) { |
| return; |
| } |
| } |
| /* We are the last completed job, commit the transaction. */ |
| QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) { |
| ctx = blk_get_aio_context(other_job->blk); |
| aio_context_acquire(ctx); |
| assert(other_job->ret == 0); |
| block_job_completed_single(other_job); |
| aio_context_release(ctx); |
| } |
| } |
| |
| void block_job_completed(BlockJob *job, int ret) |
| { |
| assert(blk_bs(job->blk)->job == job); |
| assert(!job->completed); |
| job->completed = true; |
| job->ret = ret; |
| if (!job->txn) { |
| block_job_completed_single(job); |
| } else if (ret < 0 || block_job_is_cancelled(job)) { |
| block_job_completed_txn_abort(job); |
| } else { |
| block_job_completed_txn_success(job); |
| } |
| } |
| |
| void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) |
| { |
| Error *local_err = NULL; |
| |
| if (!job->driver->set_speed) { |
| error_setg(errp, QERR_UNSUPPORTED); |
| return; |
| } |
| job->driver->set_speed(job, speed, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| return; |
| } |
| |
| job->speed = speed; |
| } |
| |
| void block_job_complete(BlockJob *job, Error **errp) |
| { |
| if (job->pause_count || job->cancelled || !job->driver->complete) { |
| error_setg(errp, "The active block job '%s' cannot be completed", |
| job->id); |
| return; |
| } |
| |
| job->driver->complete(job, errp); |
| } |
| |
| void block_job_pause(BlockJob *job) |
| { |
| job->pause_count++; |
| } |
| |
| static bool block_job_should_pause(BlockJob *job) |
| { |
| return job->pause_count > 0; |
| } |
| |
| void coroutine_fn block_job_pause_point(BlockJob *job) |
| { |
| if (!block_job_should_pause(job)) { |
| return; |
| } |
| if (block_job_is_cancelled(job)) { |
| return; |
| } |
| |
| if (job->driver->pause) { |
| job->driver->pause(job); |
| } |
| |
| if (block_job_should_pause(job) && !block_job_is_cancelled(job)) { |
| job->paused = true; |
| job->busy = false; |
| qemu_coroutine_yield(); /* wait for block_job_resume() */ |
| job->busy = true; |
| job->paused = false; |
| } |
| |
| if (job->driver->resume) { |
| job->driver->resume(job); |
| } |
| } |
| |
| void block_job_resume(BlockJob *job) |
| { |
| assert(job->pause_count > 0); |
| job->pause_count--; |
| if (job->pause_count) { |
| return; |
| } |
| block_job_enter(job); |
| } |
| |
| void block_job_enter(BlockJob *job) |
| { |
| if (job->co && !job->busy) { |
| qemu_coroutine_enter(job->co); |
| } |
| } |
| |
| void block_job_cancel(BlockJob *job) |
| { |
| job->cancelled = true; |
| block_job_iostatus_reset(job); |
| block_job_enter(job); |
| } |
| |
| bool block_job_is_cancelled(BlockJob *job) |
| { |
| return job->cancelled; |
| } |
| |
| void block_job_iostatus_reset(BlockJob *job) |
| { |
| job->iostatus = BLOCK_DEVICE_IO_STATUS_OK; |
| if (job->driver->iostatus_reset) { |
| job->driver->iostatus_reset(job); |
| } |
| } |
| |
| static int block_job_finish_sync(BlockJob *job, |
| void (*finish)(BlockJob *, Error **errp), |
| Error **errp) |
| { |
| Error *local_err = NULL; |
| int ret; |
| |
| assert(blk_bs(job->blk)->job == job); |
| |
| block_job_ref(job); |
| finish(job, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| block_job_unref(job); |
| return -EBUSY; |
| } |
| while (!job->completed) { |
| aio_poll(block_job_get_aio_context(job), true); |
| } |
| ret = (job->cancelled && job->ret == 0) ? -ECANCELED : job->ret; |
| block_job_unref(job); |
| return ret; |
| } |
| |
| /* A wrapper around block_job_cancel() taking an Error ** parameter so it may be |
| * used with block_job_finish_sync() without the need for (rather nasty) |
| * function pointer casts there. */ |
| static void block_job_cancel_err(BlockJob *job, Error **errp) |
| { |
| block_job_cancel(job); |
| } |
| |
| int block_job_cancel_sync(BlockJob *job) |
| { |
| return block_job_finish_sync(job, &block_job_cancel_err, NULL); |
| } |
| |
| void block_job_cancel_sync_all(void) |
| { |
| BlockJob *job; |
| AioContext *aio_context; |
| |
| while ((job = QLIST_FIRST(&block_jobs))) { |
| aio_context = blk_get_aio_context(job->blk); |
| aio_context_acquire(aio_context); |
| block_job_cancel_sync(job); |
| aio_context_release(aio_context); |
| } |
| } |
| |
| int block_job_complete_sync(BlockJob *job, Error **errp) |
| { |
| return block_job_finish_sync(job, &block_job_complete, errp); |
| } |
| |
| void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns) |
| { |
| assert(job->busy); |
| |
| /* Check cancellation *before* setting busy = false, too! */ |
| if (block_job_is_cancelled(job)) { |
| return; |
| } |
| |
| job->busy = false; |
| if (!block_job_should_pause(job)) { |
| co_aio_sleep_ns(blk_get_aio_context(job->blk), type, ns); |
| } |
| job->busy = true; |
| |
| block_job_pause_point(job); |
| } |
| |
| void block_job_yield(BlockJob *job) |
| { |
| assert(job->busy); |
| |
| /* Check cancellation *before* setting busy = false, too! */ |
| if (block_job_is_cancelled(job)) { |
| return; |
| } |
| |
| job->busy = false; |
| if (!block_job_should_pause(job)) { |
| qemu_coroutine_yield(); |
| } |
| job->busy = true; |
| |
| block_job_pause_point(job); |
| } |
| |
| BlockJobInfo *block_job_query(BlockJob *job) |
| { |
| BlockJobInfo *info = g_new0(BlockJobInfo, 1); |
| info->type = g_strdup(BlockJobType_lookup[job->driver->job_type]); |
| info->device = g_strdup(job->id); |
| info->len = job->len; |
| info->busy = job->busy; |
| info->paused = job->pause_count > 0; |
| info->offset = job->offset; |
| info->speed = job->speed; |
| info->io_status = job->iostatus; |
| info->ready = job->ready; |
| 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; |
| } |
| } |
| |
| void block_job_event_cancelled(BlockJob *job) |
| { |
| qapi_event_send_block_job_cancelled(job->driver->job_type, |
| job->id, |
| job->len, |
| job->offset, |
| job->speed, |
| &error_abort); |
| } |
| |
| void block_job_event_completed(BlockJob *job, const char *msg) |
| { |
| qapi_event_send_block_job_completed(job->driver->job_type, |
| job->id, |
| job->len, |
| job->offset, |
| job->speed, |
| !!msg, |
| msg, |
| &error_abort); |
| } |
| |
| void block_job_event_ready(BlockJob *job) |
| { |
| job->ready = true; |
| |
| qapi_event_send_block_job_ready(job->driver->job_type, |
| job->id, |
| job->len, |
| job->offset, |
| job->speed, &error_abort); |
| } |
| |
| 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(); |
| } |
| qapi_event_send_block_job_error(job->id, |
| is_read ? IO_OPERATION_TYPE_READ : |
| IO_OPERATION_TYPE_WRITE, |
| action, &error_abort); |
| if (action == BLOCK_ERROR_ACTION_STOP) { |
| /* make the pause user visible, which will be resumed from QMP. */ |
| job->user_paused = true; |
| block_job_pause(job); |
| block_job_iostatus_set_err(job, error); |
| } |
| return action; |
| } |
| |
| typedef struct { |
| BlockJob *job; |
| QEMUBH *bh; |
| AioContext *aio_context; |
| BlockJobDeferToMainLoopFn *fn; |
| void *opaque; |
| } BlockJobDeferToMainLoopData; |
| |
| static void block_job_defer_to_main_loop_bh(void *opaque) |
| { |
| BlockJobDeferToMainLoopData *data = opaque; |
| AioContext *aio_context; |
| |
| qemu_bh_delete(data->bh); |
| |
| /* Prevent race with block_job_defer_to_main_loop() */ |
| aio_context_acquire(data->aio_context); |
| |
| /* Fetch BDS AioContext again, in case it has changed */ |
| aio_context = blk_get_aio_context(data->job->blk); |
| aio_context_acquire(aio_context); |
| |
| data->job->deferred_to_main_loop = false; |
| data->fn(data->job, data->opaque); |
| |
| aio_context_release(aio_context); |
| |
| aio_context_release(data->aio_context); |
| |
| g_free(data); |
| } |
| |
| void block_job_defer_to_main_loop(BlockJob *job, |
| BlockJobDeferToMainLoopFn *fn, |
| void *opaque) |
| { |
| BlockJobDeferToMainLoopData *data = g_malloc(sizeof(*data)); |
| data->job = job; |
| data->bh = qemu_bh_new(block_job_defer_to_main_loop_bh, data); |
| data->aio_context = blk_get_aio_context(job->blk); |
| data->fn = fn; |
| data->opaque = opaque; |
| job->deferred_to_main_loop = true; |
| |
| qemu_bh_schedule(data->bh); |
| } |
| |
| BlockJobTxn *block_job_txn_new(void) |
| { |
| BlockJobTxn *txn = g_new0(BlockJobTxn, 1); |
| QLIST_INIT(&txn->jobs); |
| txn->refcnt = 1; |
| return txn; |
| } |
| |
| static void block_job_txn_ref(BlockJobTxn *txn) |
| { |
| txn->refcnt++; |
| } |
| |
| void block_job_txn_unref(BlockJobTxn *txn) |
| { |
| if (txn && --txn->refcnt == 0) { |
| g_free(txn); |
| } |
| } |
| |
| void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job) |
| { |
| if (!txn) { |
| return; |
| } |
| |
| assert(!job->txn); |
| job->txn = txn; |
| |
| QLIST_INSERT_HEAD(&txn->jobs, job, txn_list); |
| block_job_txn_ref(txn); |
| } |