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_complete(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_pause(BlockJob *job)
 103 {
 104     job->paused = true;
 105 }
 106
 107 bool block_job_is_paused(BlockJob *job)
 108 {
 109     return job->paused;
 110 }
 111
 112 void block_job_resume(BlockJob *job)
 113 {
 114     job->paused = false;
 115     if (job->co && !job->busy) {
 116         qemu_coroutine_enter(job->co, NULL);
 117     }
 118 }
 119
 120 void block_job_cancel(BlockJob *job)
 121 {
 122     job->cancelled = true;
 123     block_job_resume(job);
 124 }
 125
 126 bool block_job_is_cancelled(BlockJob *job)
 127 {
 128     return job->cancelled;
 129 }
 130
 131 struct BlockCancelData {
 132     BlockJob *job;
 133     BlockDriverCompletionFunc *cb;
 134     void *opaque;
 135     bool cancelled;
 136     int ret;
 137 };
 138
 139 static void block_job_cancel_cb(void *opaque, int ret)
 140 {
 141     struct BlockCancelData *data = opaque;
 142
 143     data->cancelled = block_job_is_cancelled(data->job);
 144     data->ret = ret;
 145     data->cb(data->opaque, ret);
 146 }
 147
 148 int block_job_cancel_sync(BlockJob *job)
 149 {
 150     struct BlockCancelData data;
 151     BlockDriverState *bs = job->bs;
 152
 153     assert(bs->job == job);
 154
 155     /* Set up our own callback to store the result and chain to
 156      * the original callback.
 157      */
 158     data.job = job;
 159     data.cb = job->cb;
 160     data.opaque = job->opaque;
 161     data.ret = -EINPROGRESS;
 162     job->cb = block_job_cancel_cb;
 163     job->opaque = &data;
 164     block_job_cancel(job);
 165     while (data.ret == -EINPROGRESS) {
 166         qemu_aio_wait();
 167     }
 168     return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
 169 }
 170
 171 void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns)
 172 {
 173     assert(job->busy);
 174
 175     /* Check cancellation *before* setting busy = false, too!  */
 176     if (block_job_is_cancelled(job)) {
 177         return;
 178     }
 179
 180     job->busy = false;
 181     if (block_job_is_paused(job)) {
 182         qemu_coroutine_yield();
 183     } else {
 184         co_sleep_ns(clock, ns);
 185     }
 186     job->busy = true;
 187 }
 188
 189 BlockJobInfo *block_job_query(BlockJob *job)
 190 {
 191     BlockJobInfo *info = g_new0(BlockJobInfo, 1);
 192     info->type   = g_strdup(job->job_type->job_type);
 193     info->device = g_strdup(bdrv_get_device_name(job->bs));
 194     info->len    = job->len;
 195     info->busy   = job->busy;
 196     info->paused = job->paused;
 197     info->offset = job->offset;
 198     info->speed  = job->speed;
 199     return info;
 200 }