block/create.c

   1 /*
   2  * Block layer code related to image creation
   3  *
   4  * Copyright (c) 2018 Kevin Wolf <kwolf@redhat.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "qemu/osdep.h"
  26 #include "block/block_int.h"
  27 #include "qemu/job.h"
  28 #include "qemu/main-loop.h"
  29 #include "qapi/qapi-commands-block-core.h"
  30 #include "qapi/qapi-visit-block-core.h"
  31 #include "qapi/clone-visitor.h"
  32 #include "qapi/error.h"
  33
  34 typedef struct BlockdevCreateJob {
  35     Job common;
  36     BlockDriver *drv;
  37     BlockdevCreateOptions *opts;
  38 } BlockdevCreateJob;
  39
  40 static int coroutine_fn blockdev_create_run(Job *job, Error **errp)
  41 {
  42     BlockdevCreateJob *s = container_of(job, BlockdevCreateJob, common);
  43     int ret;
  44
  45     GLOBAL_STATE_CODE();
  46     GRAPH_RDLOCK_GUARD();
  47
  48     job_progress_set_remaining(&s->common, 1);
  49     ret = s->drv->bdrv_co_create(s->opts, errp);
  50     job_progress_update(&s->common, 1);
  51
  52     qapi_free_BlockdevCreateOptions(s->opts);
  53
  54     return ret;
  55 }
  56
  57 static const JobDriver blockdev_create_job_driver = {
  58     .instance_size = sizeof(BlockdevCreateJob),
  59     .job_type      = JOB_TYPE_CREATE,
  60     .run           = blockdev_create_run,
  61 };
  62
  63 /* Checking whether the function is present doesn't require the graph lock */
  64 static inline bool TSA_NO_TSA has_bdrv_co_create(BlockDriver *drv)
  65 {
  66     return drv->bdrv_co_create;
  67 }
  68
  69 void qmp_blockdev_create(const char *job_id, BlockdevCreateOptions *options,
  70                          Error **errp)
  71 {
  72     BlockdevCreateJob *s;
  73     const char *fmt = BlockdevDriver_str(options->driver);
  74     BlockDriver *drv = bdrv_find_format(fmt);
  75
  76     if (!drv) {
  77         error_setg(errp, "Block driver '%s' not found or not supported", fmt);
  78         return;
  79     }
  80
  81     /* If the driver is in the schema, we know that it exists. But it may not
  82      * be whitelisted. */
  83     if (bdrv_uses_whitelist() && !bdrv_is_whitelisted(drv, false)) {
  84         error_setg(errp, "Driver is not whitelisted");
  85         return;
  86     }
  87
  88     /* Error out if the driver doesn't support .bdrv_co_create */
  89     if (!has_bdrv_co_create(drv)) {
  90         error_setg(errp, "Driver does not support blockdev-create");
  91         return;
  92     }
  93
  94     /* Create the block job */
  95     /* TODO Running in the main context. Block drivers need to error out or add
  96      * locking when they use a BDS in a different AioContext. */
  97     s = job_create(job_id, &blockdev_create_job_driver, NULL,
  98                    qemu_get_aio_context(), JOB_DEFAULT | JOB_MANUAL_DISMISS,
  99                    NULL, NULL, errp);
 100     if (!s) {
 101         return;
 102     }
 103
 104     s->drv = drv,
 105     s->opts = QAPI_CLONE(BlockdevCreateOptions, options),
 106
 107     job_start(&s->common);
 108 }