xref: /openbmc/qemu/block/create.c (revision c5c0fdbe)
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 }
109