blockjob.c

   1 /*
   2  * QEMU System Emulator block driver
   3  *
   4  * Copyright (c) 2011 IBM Corp.
   5  * Copyright (c) 2012 Red Hat, Inc.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23  * THE SOFTWARE.
  24  */
  25
  26 #include "config-host.h"
  27 #include "qemu-common.h"
  28 #include "trace.h"
  29 #include "monitor/monitor.h"
  30 #include "block/block.h"
  31 #include "block/blockjob.h"
  32 #include "block/block_int.h"
  33 #include "qapi/qmp/qjson.h"
  34 #include "block/coroutine.h"
  35 #include "qmp-commands.h"
  36 #include "qemu/timer.h"
  37
  38 void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
  39                        int64_t speed, BlockDriverCompletionFunc *cb,
  40                        void *opaque, Error **errp)
  41 {
  42     BlockJob *job;
  43
  44     if (bs->job || bdrv_in_use(bs)) {
  45         error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
  46         return NULL;
  47     }
  48     bdrv_ref(bs);
  49     bdrv_set_in_use(bs, 1);
  50
  51     job = g_malloc0(driver->instance_size);
  52     job->driver        = driver;
  53     job->bs            = bs;
  54     job->cb            = cb;
  55     job->opaque        = opaque;
  56     job->busy          = true;
  57     bs->job = job;
  58
  59     /* Only set speed when necessary to avoid NotSupported error */
  60     if (speed != 0) {
  61         Error *local_err = NULL;
  62
  63         block_job_set_speed(job, speed, &local_err);
  64         if (error_is_set(&local_err)) {
  65             bs->job = NULL;
  66             g_free(job);
  67             bdrv_set_in_use(bs, 0);
  68             error_propagate(errp, local_err);
  69             return NULL;
  70         }
  71     }
  72     return job;
  73 }
  74
  75 void block_job_completed(BlockJob *job, int ret)
  76 {
  77     BlockDriverState *bs = job->bs;
  78
  79     assert(bs->job == job);
  80     job->cb(job->opaque, ret);
  81     bs->job = NULL;
  82     g_free(job);
  83     bdrv_set_in_use(bs, 0);
  84 }
  85
  86 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
  87 {
  88     Error *local_err = NULL;
  89
  90     if (!job->driver->set_speed) {
  91         error_set(errp, QERR_NOT_SUPPORTED);
  92         return;
  93     }
  94     job->driver->set_speed(job, speed, &local_err);
  95     if (error_is_set(&local_err)) {
  96         error_propagate(errp, local_err);
  97         return;
  98     }
  99
 100     job->speed = speed;
 101 }
 102
 103 void block_job_complete(BlockJob *job, Error **errp)
 104 {
 105     if (job->paused || job->cancelled || !job->driver->complete) {
 106         error_set(errp, QERR_BLOCK_JOB_NOT_READY, job->bs->device_name);
 107         return;
 108     }
 109
 110     job->driver->complete(job, errp);
 111 }
 112
 113 void block_job_pause(BlockJob *job)
 114 {
 115     job->paused = true;
 116 }
 117
 118 bool block_job_is_paused(BlockJob *job)
 119 {
 120     return job->paused;
 121 }
 122
 123 void block_job_resume(BlockJob *job)
 124 {
 125     job->paused = false;
 126     block_job_iostatus_reset(job);
 127     if (job->co && !job->busy) {
 128         qemu_coroutine_enter(job->co, NULL);
 129     }
 130 }
 131
 132 void block_job_cancel(BlockJob *job)
 133 {
 134     job->cancelled = true;
 135     block_job_resume(job);
 136 }
 137
 138 bool block_job_is_cancelled(BlockJob *job)
 139 {
 140     return job->cancelled;
 141 }
 142
 143 void block_job_iostatus_reset(BlockJob *job)
 144 {
 145     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
 146     if (job->driver->iostatus_reset) {
 147         job->driver->iostatus_reset(job);
 148     }
 149 }
 150
 151 struct BlockCancelData {
 152     BlockJob *job;
 153     BlockDriverCompletionFunc *cb;
 154     void *opaque;
 155     bool cancelled;
 156     int ret;
 157 };
 158
 159 static void block_job_cancel_cb(void *opaque, int ret)
 160 {
 161     struct BlockCancelData *data = opaque;
 162
 163     data->cancelled = block_job_is_cancelled(data->job);
 164     data->ret = ret;
 165     data->cb(data->opaque, ret);
 166 }
 167
 168 int block_job_cancel_sync(BlockJob *job)
 169 {
 170     struct BlockCancelData data;
 171     BlockDriverState *bs = job->bs;
 172
 173     assert(bs->job == job);
 174
 175     /* Set up our own callback to store the result and chain to
 176      * the original callback.
 177      */
 178     data.job = job;
 179     data.cb = job->cb;
 180     data.opaque = job->opaque;
 181     data.ret = -EINPROGRESS;
 182     job->cb = block_job_cancel_cb;
 183     job->opaque = &data;
 184     block_job_cancel(job);
 185     while (data.ret == -EINPROGRESS) {
 186         qemu_aio_wait();
 187     }
 188     return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
 189 }
 190
 191 void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns)
 192 {
 193     assert(job->busy);
 194
 195     /* Check cancellation *before* setting busy = false, too!  */
 196     if (block_job_is_cancelled(job)) {
 197         return;
 198     }
 199
 200     job->busy = false;
 201     if (block_job_is_paused(job)) {
 202         qemu_coroutine_yield();
 203     } else {
 204         co_sleep_ns(type, ns);
 205     }
 206     job->busy = true;
 207 }
 208
 209 BlockJobInfo *block_job_query(BlockJob *job)
 210 {
 211     BlockJobInfo *info = g_new0(BlockJobInfo, 1);
 212     info->type      = g_strdup(BlockJobType_lookup[job->driver->job_type]);
 213     info->device    = g_strdup(bdrv_get_device_name(job->bs));
 214     info->len       = job->len;
 215     info->busy      = job->busy;
 216     info->paused    = job->paused;
 217     info->offset    = job->offset;
 218     info->speed     = job->speed;
 219     info->io_status = job->iostatus;
 220     return info;
 221 }
 222
 223 static void block_job_iostatus_set_err(BlockJob *job, int error)
 224 {
 225     if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
 226         job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
 227                                           BLOCK_DEVICE_IO_STATUS_FAILED;
 228     }
 229 }
 230
 231
 232 QObject *qobject_from_block_job(BlockJob *job)
 233 {
 234     return qobject_from_jsonf("{ 'type': %s,"
 235                               "'device': %s,"
 236                               "'len': %" PRId64 ","
 237                               "'offset': %" PRId64 ","
 238                               "'speed': %" PRId64 " }",
 239                               BlockJobType_lookup[job->driver->job_type],
 240                               bdrv_get_device_name(job->bs),
 241                               job->len,
 242                               job->offset,
 243                               job->speed);
 244 }
 245
 246 void block_job_ready(BlockJob *job)
 247 {
 248     QObject *data = qobject_from_block_job(job);
 249     monitor_protocol_event(QEVENT_BLOCK_JOB_READY, data);
 250     qobject_decref(data);
 251 }
 252
 253 BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs,
 254                                         BlockdevOnError on_err,
 255                                         int is_read, int error)
 256 {
 257     BlockErrorAction action;
 258
 259     switch (on_err) {
 260     case BLOCKDEV_ON_ERROR_ENOSPC:
 261         action = (error == ENOSPC) ? BDRV_ACTION_STOP : BDRV_ACTION_REPORT;
 262         break;
 263     case BLOCKDEV_ON_ERROR_STOP:
 264         action = BDRV_ACTION_STOP;
 265         break;
 266     case BLOCKDEV_ON_ERROR_REPORT:
 267         action = BDRV_ACTION_REPORT;
 268         break;
 269     case BLOCKDEV_ON_ERROR_IGNORE:
 270         action = BDRV_ACTION_IGNORE;
 271         break;
 272     default:
 273         abort();
 274     }
 275     bdrv_emit_qmp_error_event(job->bs, QEVENT_BLOCK_JOB_ERROR, action, is_read);
 276     if (action == BDRV_ACTION_STOP) {
 277         block_job_pause(job);
 278         block_job_iostatus_set_err(job, error);
 279         if (bs != job->bs) {
 280             bdrv_iostatus_set_err(bs, error);
 281         }
 282     }
 283     return action;
 284 }