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-io.h"
  30 #include "block/block_int.h"
  31 #include "qemu/job.h"
  32 #include "qemu/main-loop.h"
  33 #include "qapi/qapi-commands-block-core.h"
  34 #include "qapi/qapi-visit-block-core.h"
  35 #include "qapi/clone-visitor.h"
  36 #include "qapi/error.h"
  37
  38 typedef struct BlockdevAmendJob {
  39     Job common;
  40     BlockdevAmendOptions *opts;
  41     BlockDriverState *bs;
  42     bool force;
  43 } BlockdevAmendJob;
  44
  45 static int coroutine_fn blockdev_amend_run(Job *job, Error **errp)
  46 {
  47     BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
  48     int ret;
  49     GRAPH_RDLOCK_GUARD();
  50
  51     job_progress_set_remaining(&s->common, 1);
  52     ret = s->bs->drv->bdrv_co_amend(s->bs, s->opts, s->force, errp);
  53     job_progress_update(&s->common, 1);
  54     qapi_free_BlockdevAmendOptions(s->opts);
  55     return ret;
  56 }
  57
  58 static int GRAPH_RDLOCK
  59 blockdev_amend_pre_run(BlockdevAmendJob *s, Error **errp)
  60 {
  61     if (s->bs->drv->bdrv_amend_pre_run) {
  62         return s->bs->drv->bdrv_amend_pre_run(s->bs, errp);
  63     }
  64
  65     return 0;
  66 }
  67
  68 static void blockdev_amend_free(Job *job)
  69 {
  70     BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
  71
  72     bdrv_graph_rdlock_main_loop();
  73     if (s->bs->drv->bdrv_amend_clean) {
  74         s->bs->drv->bdrv_amend_clean(s->bs);
  75     }
  76     bdrv_graph_rdunlock_main_loop();
  77
  78     bdrv_unref(s->bs);
  79 }
  80
  81 static const JobDriver blockdev_amend_job_driver = {
  82     .instance_size = sizeof(BlockdevAmendJob),
  83     .job_type      = JOB_TYPE_AMEND,
  84     .run           = blockdev_amend_run,
  85     .free          = blockdev_amend_free,
  86 };
  87
  88 void qmp_x_blockdev_amend(const char *job_id,
  89                           const char *node_name,
  90                           BlockdevAmendOptions *options,
  91                           bool has_force,
  92                           bool force,
  93                           Error **errp)
  94 {
  95     BlockdevAmendJob *s;
  96     const char *fmt = BlockdevDriver_str(options->driver);
  97     BlockDriver *drv = bdrv_find_format(fmt);
  98     BlockDriverState *bs;
  99
 100     GRAPH_RDLOCK_GUARD_MAINLOOP();
 101
 102     bs = bdrv_lookup_bs(NULL, node_name, errp);
 103     if (!bs) {
 104         return;
 105     }
 106
 107     if (!drv) {
 108         error_setg(errp, "Block driver '%s' not found or not supported", fmt);
 109         return;
 110     }
 111
 112     /*
 113      * If the driver is in the schema, we know that it exists. But it may not
 114      * be whitelisted.
 115      */
 116     if (bdrv_uses_whitelist() && !bdrv_is_whitelisted(drv, false)) {
 117         error_setg(errp, "Driver is not whitelisted");
 118         return;
 119     }
 120
 121     if (bs->drv != drv) {
 122         error_setg(errp,
 123                    "x-blockdev-amend doesn't support changing the block driver");
 124         return;
 125     }
 126
 127     /* Error out if the driver doesn't support .bdrv_co_amend */
 128     if (!drv->bdrv_co_amend) {
 129         error_setg(errp, "Driver does not support x-blockdev-amend");
 130         return;
 131     }
 132
 133     /* Create the block job */
 134     s = job_create(job_id, &blockdev_amend_job_driver, NULL,
 135                    bdrv_get_aio_context(bs), JOB_DEFAULT | JOB_MANUAL_DISMISS,
 136                    NULL, NULL, errp);
 137     if (!s) {
 138         return;
 139     }
 140
 141     bdrv_ref(bs);
 142     s->bs = bs,
 143     s->opts = QAPI_CLONE(BlockdevAmendOptions, options),
 144     s->force = has_force ? force : false;
 145
 146     if (blockdev_amend_pre_run(s, errp)) {
 147         job_early_fail(&s->common);
 148         return;
 149     }
 150
 151     job_start(&s->common);
 152 }