LXR qemu/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
  38typedef struct BlockdevAmendJob {
  39    Job common;
  40    BlockdevAmendOptions *opts;
  41    BlockDriverState *bs;
  42    bool force;
  43} BlockdevAmendJob;
  44
  45static 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
  58static int GRAPH_RDLOCK
  59blockdev_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
  68static 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
  81static 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
  88void 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}
 153