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.h"
  30 #include "block.h"
  31 #include "blockjob.h"
  32 #include "block_int.h"
  33 #include "qjson.h"
  34 #include "qemu-coroutine.h"
  35 #include "qmp-commands.h"
  36 #include "qemu-timer.h"
  37
  38 void *block_job_create(const BlockJobType *job_type, 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_set_in_use(bs, 1);
  49
  50     job = g_malloc0(job_type->instance_size);
  51     job->job_type      = job_type;
  52     job->bs            = bs;
  53     job->cb            = cb;
  54     job->opaque        = opaque;
  55     job->busy          = true;
  56     bs->job = job;
  57
  58     /* Only set speed when necessary to avoid NotSupported error */
  59     if (speed != 0) {
  60         Error *local_err = NULL;
  61
  62         block_job_set_speed(job, speed, &local_err);
  63         if (error_is_set(&local_err)) {
  64             bs->job = NULL;
  65             g_free(job);
  66             bdrv_set_in_use(bs, 0);
  67             error_propagate(errp, local_err);
  68             return NULL;
  69         }
  70     }
  71     return job;
  72 }
  73
  74 void block_job_completed(BlockJob *job, int ret)
  75 {
  76     BlockDriverState *bs = job->bs;
  77
  78     assert(bs->job == job);
  79     job->cb(job->opaque, ret);
  80     bs->job = NULL;
  81     g_free(job);
  82     bdrv_set_in_use(bs, 0);
  83 }
  84
  85 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
  86 {
  87     Error *local_err = NULL;
  88
  89     if (!job->job_type->set_speed) {
  90         error_set(errp, QERR_NOT_SUPPORTED);
  91         return;
  92     }
  93     job->job_type->set_speed(job, speed, &local_err);
  94     if (error_is_set(&local_err)) {
  95         error_propagate(errp, local_err);
  96         return;
  97     }
  98
  99     job->speed = speed;
 100 }
 101
 102 void block_job_complete(BlockJob *job, Error **errp)
 103 {
 104     if (job->paused || job->cancelled || !job->job_type->complete) {
 105         error_set(errp, QERR_BLOCK_JOB_NOT_READY, job->bs->device_name);
 106         return;
 107     }
 108
 109     job->job_type->complete(job, errp);
 110 }
 111
 112 void block_job_pause(BlockJob *job)
 113 {
 114     job->paused = true;
 115 }
 116
 117 bool block_job_is_paused(BlockJob *job)
 118 {
 119     return job->paused;
 120 }
 121
 122 void block_job_resume(BlockJob *job)
 123 {
 124     job->paused = false;
 125     block_job_iostatus_reset(job);
 126     if (job->co && !job->busy) {
 127         qemu_coroutine_enter(job->co, NULL);
 128     }
 129 }
 130
 131 void block_job_cancel(BlockJob *job)
 132 {
 133     job->cancelled = true;
 134     block_job_resume(job);
 135 }
 136
 137 bool block_job_is_cancelled(BlockJob *job)
 138 {
 139     return job->cancelled;
 140 }
 141
 142 void block_job_iostatus_reset(BlockJob *job)
 143 {
 144     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
 145     if (job->job_type->iostatus_reset) {
 146         job->job_type->iostatus_reset(job);
 147     }
 148 }
 149
 150 struct BlockCancelData {
 151     BlockJob *job;
 152     BlockDriverCompletionFunc *cb;
 153     void *opaque;
 154     bool cancelled;
 155     int ret;
 156 };
 157
 158 static void block_job_cancel_cb(void *opaque, int ret)
 159 {
 160     struct BlockCancelData *data = opaque;
 161
 162     data->cancelled = block_job_is_cancelled(data->job);
 163     data->ret = ret;
 164     data->cb(data->opaque, ret);
 165 }
 166
 167 int block_job_cancel_sync(BlockJob *job)
 168 {
 169     struct BlockCancelData data;
 170     BlockDriverState *bs = job->bs;
 171
 172     assert(bs->job == job);
 173
 174     /* Set up our own callback to store the result and chain to
 175      * the original callback.
 176      */
 177     data.job = job;
 178     data.cb = job->cb;
 179     data.opaque = job->opaque;
 180     data.ret = -EINPROGRESS;
 181     job->cb = block_job_cancel_cb;
 182     job->opaque = &data;
 183     block_job_cancel(job);
 184     while (data.ret == -EINPROGRESS) {
 185         qemu_aio_wait();
 186     }
 187     return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
 188 }
 189
 190 void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns)
 191 {
 192     assert(job->busy);
 193
 194     /* Check cancellation *before* setting busy = false, too!  */
 195     if (block_job_is_cancelled(job)) {
 196         return;
 197     }
 198
 199     job->busy = false;
 200     if (block_job_is_paused(job)) {
 201         qemu_coroutine_yield();
 202     } else {
 203         co_sleep_ns(clock, ns);
 204     }
 205     job->busy = true;
 206 }
 207
 208 BlockJobInfo *block_job_query(BlockJob *job)
 209 {
 210     BlockJobInfo *info = g_new0(BlockJobInfo, 1);
 211     info->type      = g_strdup(job->job_type->job_type);
 212     info->device    = g_strdup(bdrv_get_device_name(job->bs));
 213     info->len       = job->len;
 214     info->busy      = job->busy;
 215     info->paused    = job->paused;
 216     info->offset    = job->offset;
 217     info->speed     = job->speed;
 218     info->io_status = job->iostatus;
 219     return info;
 220 }
 221
 222 static void block_job_iostatus_set_err(BlockJob *job, int error)
 223 {
 224     if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
 225         job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
 226                                           BLOCK_DEVICE_IO_STATUS_FAILED;
 227     }
 228 }
 229
 230
 231 QObject *qobject_from_block_job(BlockJob *job)
 232 {
 233     return qobject_from_jsonf("{ 'type': %s,"
 234                               "'device': %s,"
 235                               "'len': %" PRId64 ","
 236                               "'offset': %" PRId64 ","
 237                               "'speed': %" PRId64 " }",
 238                               job->job_type->job_type,
 239                               bdrv_get_device_name(job->bs),
 240                               job->len,
 241                               job->offset,
 242                               job->speed);
 243 }
 244
 245 void block_job_ready(BlockJob *job)
 246 {
 247     QObject *data = qobject_from_block_job(job);
 248     monitor_protocol_event(QEVENT_BLOCK_JOB_READY, data);
 249     qobject_decref(data);
 250 }
 251
 252 BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs,
 253                                         BlockdevOnError on_err,
 254                                         int is_read, int error)
 255 {
 256     BlockErrorAction action;
 257
 258     switch (on_err) {
 259     case BLOCKDEV_ON_ERROR_ENOSPC:
 260         action = (error == ENOSPC) ? BDRV_ACTION_STOP : BDRV_ACTION_REPORT;
 261         break;
 262     case BLOCKDEV_ON_ERROR_STOP:
 263         action = BDRV_ACTION_STOP;
 264         break;
 265     case BLOCKDEV_ON_ERROR_REPORT:
 266         action = BDRV_ACTION_REPORT;
 267         break;
 268     case BLOCKDEV_ON_ERROR_IGNORE:
 269         action = BDRV_ACTION_IGNORE;
 270         break;
 271     default:
 272         abort();
 273     }
 274     bdrv_emit_qmp_error_event(job->bs, QEVENT_BLOCK_JOB_ERROR, action, is_read);
 275     if (action == BDRV_ACTION_STOP) {
 276         block_job_pause(job);
 277         block_job_iostatus_set_err(job, error);
 278         if (bs != job->bs) {
 279             bdrv_iostatus_set_err(bs, error);
 280         }
 281     }
 282     return action;
 283 }