block/amend.c

   1 /*
   2  * Block layer code related to image options amend
   3  *
   4  * Copyright (c) 2018 Kevin Wolf <kwolf@redhat.com>
   5  * Copyright (c) 2020 Red Hat. Inc
   6  *
   7  * Heavily based on create.c
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a copy
  10  * of this software and associated documentation files (the "Software"), to deal
  11  * in the Software without restriction, including without limitation the rights
  12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13  * copies of the Software, and to permit persons to whom the Software is
  14  * furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  25  * THE SOFTWARE.
  26  */
  27
  28 #include "qemu/osdep.h"
  29 #include "block/block_int.h"
  30 #include "qemu/job.h"
  31 #include "qemu/main-loop.h"
  32 #include "qapi/qapi-commands-block-core.h"
  33 #include "qapi/qapi-visit-block-core.h"
  34 #include "qapi/clone-visitor.h"
  35 #include "qapi/error.h"
  36
  37 typedef struct BlockdevAmendJob {
  38     Job common;
  39     BlockdevAmendOptions *opts;
  40     BlockDriverState *bs;
  41     bool force;
  42 } BlockdevAmendJob;
  43
  44 static int coroutine_fn blockdev_amend_run(Job *job, Error **errp)
  45 {
  46     BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
  47     int ret;
  48
  49     job_progress_set_remaining(&s->common, 1);
  50     ret = s->bs->drv->bdrv_co_amend(s->bs, s->opts, s->force, errp);
  51     job_progress_update(&s->common, 1);
  52     qapi_free_BlockdevAmendOptions(s->opts);
  53     return ret;
  54 }
  55
  56 static int blockdev_amend_pre_run(BlockdevAmendJob *s, Error **errp)
  57 {
  58     if (s->bs->drv->bdrv_amend_pre_run) {
  59         return s->bs->drv->bdrv_amend_pre_run(s->bs, errp);
  60     }
  61
  62     return 0;
  63 }
  64
  65 static void blockdev_amend_free(Job *job)
  66 {
  67     BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
  68
  69     if (s->bs->drv->bdrv_amend_clean) {
  70         s->bs->drv->bdrv_amend_clean(s->bs);
  71     }
  72
  73     bdrv_unref(s->bs);
  74 }
  75
  76 static const JobDriver blockdev_amend_job_driver = {
  77     .instance_size = sizeof(BlockdevAmendJob),
  78     .job_type      = JOB_TYPE_AMEND,
  79     .run           = blockdev_amend_run,
  80     .free          = blockdev_amend_free,
  81 };
  82
  83 void qmp_x_blockdev_amend(const char *job_id,
  84                           const char *node_name,
  85                           BlockdevAmendOptions *options,
  86                           bool has_force,
  87                           bool force,
  88                           Error **errp)
  89 {
  90     BlockdevAmendJob *s;
  91     const char *fmt = BlockdevDriver_str(options->driver);
  92     BlockDriver *drv = bdrv_find_format(fmt);
  93     BlockDriverState *bs;
  94
  95     bs = bdrv_lookup_bs(NULL, node_name, errp);
  96     if (!bs) {
  97         return;
  98     }
  99
 100     if (!drv) {
 101         error_setg(errp, "Block driver '%s' not found or not supported", fmt);
 102         return;
 103     }
 104
 105     /*
 106      * If the driver is in the schema, we know that it exists. But it may not
 107      * be whitelisted.
 108      */
 109     if (bdrv_uses_whitelist() && !bdrv_is_whitelisted(drv, false)) {
 110         error_setg(errp, "Driver is not whitelisted");
 111         return;
 112     }
 113
 114     if (bs->drv != drv) {
 115         error_setg(errp,
 116                    "x-blockdev-amend doesn't support changing the block driver");
 117         return;
 118     }
 119
 120     /* Error out if the driver doesn't support .bdrv_co_amend */
 121     if (!drv->bdrv_co_amend) {
 122         error_setg(errp, "Driver does not support x-blockdev-amend");
 123         return;
 124     }
 125
 126     /* Create the block job */
 127     s = job_create(job_id, &blockdev_amend_job_driver, NULL,
 128                    bdrv_get_aio_context(bs), JOB_DEFAULT | JOB_MANUAL_DISMISS,
 129                    NULL, NULL, errp);
 130     if (!s) {
 131         return;
 132     }
 133
 134     bdrv_ref(bs);
 135     s->bs = bs,
 136     s->opts = QAPI_CLONE(BlockdevAmendOptions, options),
 137     s->force = has_force ? force : false;
 138
 139     if (blockdev_amend_pre_run(s, errp)) {
 140         job_early_fail(&s->common);
 141         return;
 142     }
 143
 144     job_start(&s->common);
 145 }