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) {
  45         error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
  46         return NULL;
  47     }
  48     bdrv_ref(bs);
  49     job = g_malloc0(driver->instance_size);
  50     error_setg(&job->blocker, "block device is in use by block job: %s",
  51                BlockJobType_lookup[driver->job_type]);
  52     bdrv_op_block_all(bs, job->blocker);
  53
  54     job->driver        = driver;
  55     job->bs            = bs;
  56     job->cb            = cb;
  57     job->opaque        = opaque;
  58     job->busy          = true;
  59     bs->job = job;
  60
  61     /* Only set speed when necessary to avoid NotSupported error */
  62     if (speed != 0) {
  63         Error *local_err = NULL;
  64
  65         block_job_set_speed(job, speed, &local_err);
  66         if (local_err) {
  67             bs->job = NULL;
  68             bdrv_op_unblock_all(bs, job->blocker);
  69             error_free(job->blocker);
  70             g_free(job);
  71             error_propagate(errp, local_err);
  72             return NULL;
  73         }
  74     }
  75     return job;
  76 }
  77
  78 void block_job_completed(BlockJob *job, int ret)
  79 {
  80     BlockDriverState *bs = job->bs;
  81
  82     assert(bs->job == job);
  83     job->cb(job->opaque, ret);
  84     bs->job = NULL;
  85     bdrv_op_unblock_all(bs, job->blocker);
  86     error_free(job->blocker);
  87     g_free(job);
  88 }
  89
  90 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
  91 {
  92     Error *local_err = NULL;
  93
  94     if (!job->driver->set_speed) {
  95         error_set(errp, QERR_UNSUPPORTED);
  96         return;
  97     }
  98     job->driver->set_speed(job, speed, &local_err);
  99     if (local_err) {
 100         error_propagate(errp, local_err);
 101         return;
 102     }
 103
 104     job->speed = speed;
 105 }
 106
 107 void block_job_complete(BlockJob *job, Error **errp)
 108 {
 109     if (job->paused || job->cancelled || !job->driver->complete) {
 110         error_set(errp, QERR_BLOCK_JOB_NOT_READY, job->bs->device_name);
 111         return;
 112     }
 113
 114     job->driver->complete(job, errp);
 115 }
 116
 117 void block_job_pause(BlockJob *job)
 118 {
 119     job->paused = true;
 120 }
 121
 122 bool block_job_is_paused(BlockJob *job)
 123 {
 124     return job->paused;
 125 }
 126
 127 void block_job_resume(BlockJob *job)
 128 {
 129     job->paused = false;
 130     block_job_iostatus_reset(job);
 131     if (job->co && !job->busy) {
 132         qemu_coroutine_enter(job->co, NULL);
 133     }
 134 }
 135
 136 void block_job_cancel(BlockJob *job)
 137 {
 138     job->cancelled = true;
 139     block_job_resume(job);
 140 }
 141
 142 bool block_job_is_cancelled(BlockJob *job)
 143 {
 144     return job->cancelled;
 145 }
 146
 147 void block_job_iostatus_reset(BlockJob *job)
 148 {
 149     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
 150     if (job->driver->iostatus_reset) {
 151         job->driver->iostatus_reset(job);
 152     }
 153 }
 154
 155 struct BlockCancelData {
 156     BlockJob *job;
 157     BlockDriverCompletionFunc *cb;
 158     void *opaque;
 159     bool cancelled;
 160     int ret;
 161 };
 162
 163 static void block_job_cancel_cb(void *opaque, int ret)
 164 {
 165     struct BlockCancelData *data = opaque;
 166
 167     data->cancelled = block_job_is_cancelled(data->job);
 168     data->ret = ret;
 169     data->cb(data->opaque, ret);
 170 }
 171
 172 int block_job_cancel_sync(BlockJob *job)
 173 {
 174     struct BlockCancelData data;
 175     BlockDriverState *bs = job->bs;
 176
 177     assert(bs->job == job);
 178
 179     /* Set up our own callback to store the result and chain to
 180      * the original callback.
 181      */
 182     data.job = job;
 183     data.cb = job->cb;
 184     data.opaque = job->opaque;
 185     data.ret = -EINPROGRESS;
 186     job->cb = block_job_cancel_cb;
 187     job->opaque = &data;
 188     block_job_cancel(job);
 189     while (data.ret == -EINPROGRESS) {
 190         qemu_aio_wait();
 191     }
 192     return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
 193 }
 194
 195 void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns)
 196 {
 197     assert(job->busy);
 198
 199     /* Check cancellation *before* setting busy = false, too!  */
 200     if (block_job_is_cancelled(job)) {
 201         return;
 202     }
 203
 204     job->busy = false;
 205     if (block_job_is_paused(job)) {
 206         qemu_coroutine_yield();
 207     } else {
 208         co_sleep_ns(type, ns);
 209     }
 210     job->busy = true;
 211 }
 212
 213 BlockJobInfo *block_job_query(BlockJob *job)
 214 {
 215     BlockJobInfo *info = g_new0(BlockJobInfo, 1);
 216     info->type      = g_strdup(BlockJobType_lookup[job->driver->job_type]);
 217     info->device    = g_strdup(bdrv_get_device_name(job->bs));
 218     info->len       = job->len;
 219     info->busy      = job->busy;
 220     info->paused    = job->paused;
 221     info->offset    = job->offset;
 222     info->speed     = job->speed;
 223     info->io_status = job->iostatus;
 224     return info;
 225 }
 226
 227 static void block_job_iostatus_set_err(BlockJob *job, int error)
 228 {
 229     if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
 230         job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
 231                                           BLOCK_DEVICE_IO_STATUS_FAILED;
 232     }
 233 }
 234
 235
 236 QObject *qobject_from_block_job(BlockJob *job)
 237 {
 238     return qobject_from_jsonf("{ 'type': %s,"
 239                               "'device': %s,"
 240                               "'len': %" PRId64 ","
 241                               "'offset': %" PRId64 ","
 242                               "'speed': %" PRId64 " }",
 243                               BlockJobType_lookup[job->driver->job_type],
 244                               bdrv_get_device_name(job->bs),
 245                               job->len,
 246                               job->offset,
 247                               job->speed);
 248 }
 249
 250 void block_job_ready(BlockJob *job)
 251 {
 252     QObject *data = qobject_from_block_job(job);
 253     monitor_protocol_event(QEVENT_BLOCK_JOB_READY, data);
 254     qobject_decref(data);
 255 }
 256
 257 BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs,
 258                                         BlockdevOnError on_err,
 259                                         int is_read, int error)
 260 {
 261     BlockErrorAction action;
 262
 263     switch (on_err) {
 264     case BLOCKDEV_ON_ERROR_ENOSPC:
 265         action = (error == ENOSPC) ? BDRV_ACTION_STOP : BDRV_ACTION_REPORT;
 266         break;
 267     case BLOCKDEV_ON_ERROR_STOP:
 268         action = BDRV_ACTION_STOP;
 269         break;
 270     case BLOCKDEV_ON_ERROR_REPORT:
 271         action = BDRV_ACTION_REPORT;
 272         break;
 273     case BLOCKDEV_ON_ERROR_IGNORE:
 274         action = BDRV_ACTION_IGNORE;
 275         break;
 276     default:
 277         abort();
 278     }
 279     bdrv_emit_qmp_error_event(job->bs, QEVENT_BLOCK_JOB_ERROR, action, is_read);
 280     if (action == BDRV_ACTION_STOP) {
 281         block_job_pause(job);
 282         block_job_iostatus_set_err(job, error);
 283         if (bs != job->bs) {
 284             bdrv_iostatus_set_err(bs, error);
 285         }
 286     }
 287     return action;
 288 }