qemu/block/amend.c

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/*
* Block layer code related to image options amend
*
* Copyright (c) 2018 Kevin Wolf <kwolf@redhat.com>
* Copyright (c) 2020 Red Hat. Inc
*
* Heavily based on create.c
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "block/block_int.h"
#include "qemu/job.h"
#include "qemu/main-loop.h"
#include "qapi/qapi-commands-block-core.h"
#include "qapi/qapi-visit-block-core.h"
#include "qapi/clone-visitor.h"
#include "qapi/error.h"
typedef struct BlockdevAmendJob {
Job common;
BlockdevAmendOptions *opts;
BlockDriverState *bs;
bool force;
} BlockdevAmendJob;
static int coroutine_fn blockdev_amend_run(Job *job, Error **errp)
{
BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
int ret;
job_progress_set_remaining(&s->common, 1);
ret = s->bs->drv->bdrv_co_amend(s->bs, s->opts, s->force, errp);
job_progress_update(&s->common, 1);
qapi_free_BlockdevAmendOptions(s->opts);
return ret;
}
crypto: perform permission checks under BQL Move the permission API calls into driver-specific callbacks that always run under BQL. In this case, bdrv_crypto_luks needs to perform permission checks before and after qcrypto_block_amend_options(). The problem is that the caller, block_crypto_amend_options_generic_luks(), can also run in I/O from .bdrv_co_amend(). This does not comply with Global State-I/O API split, as permissions API must always run under BQL. Firstly, introduce .bdrv_amend_pre_run() and .bdrv_amend_clean() callbacks. These two callbacks are guaranteed to be invoked under BQL, respectively before and after .bdrv_co_amend(). They take care of performing the permission checks in the same way as they are currently done before and after qcrypto_block_amend_options(). These callbacks are in preparation for next patch, where we delete the original permission check. Right now they just add redundant control. Then, call .bdrv_amend_pre_run() before job_start in qmp_x_blockdev_amend(), so that it will be run before the job coroutine is created and stay in the main loop. As a cleanup, use JobDriver's .clean() callback to call .bdrv_amend_clean(), and run amend-specific cleanup callbacks under BQL. After this patch, permission failures occur early in the blockdev-amend job to update a LUKS volume's keys. iotest 296 must now expect them in x-blockdev-amend's QMP reply instead of waiting for the actual job to fail later. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20220209105452.1694545-2-eesposit@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220304153729.711387-6-hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-02-09 13:54:48 +03:00
static int blockdev_amend_pre_run(BlockdevAmendJob *s, Error **errp)
{
if (s->bs->drv->bdrv_amend_pre_run) {
return s->bs->drv->bdrv_amend_pre_run(s->bs, errp);
}
return 0;
}
static void blockdev_amend_clean(Job *job)
{
BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
if (s->bs->drv->bdrv_amend_clean) {
s->bs->drv->bdrv_amend_clean(s->bs);
}
}
static const JobDriver blockdev_amend_job_driver = {
.instance_size = sizeof(BlockdevAmendJob),
.job_type = JOB_TYPE_AMEND,
.run = blockdev_amend_run,
crypto: perform permission checks under BQL Move the permission API calls into driver-specific callbacks that always run under BQL. In this case, bdrv_crypto_luks needs to perform permission checks before and after qcrypto_block_amend_options(). The problem is that the caller, block_crypto_amend_options_generic_luks(), can also run in I/O from .bdrv_co_amend(). This does not comply with Global State-I/O API split, as permissions API must always run under BQL. Firstly, introduce .bdrv_amend_pre_run() and .bdrv_amend_clean() callbacks. These two callbacks are guaranteed to be invoked under BQL, respectively before and after .bdrv_co_amend(). They take care of performing the permission checks in the same way as they are currently done before and after qcrypto_block_amend_options(). These callbacks are in preparation for next patch, where we delete the original permission check. Right now they just add redundant control. Then, call .bdrv_amend_pre_run() before job_start in qmp_x_blockdev_amend(), so that it will be run before the job coroutine is created and stay in the main loop. As a cleanup, use JobDriver's .clean() callback to call .bdrv_amend_clean(), and run amend-specific cleanup callbacks under BQL. After this patch, permission failures occur early in the blockdev-amend job to update a LUKS volume's keys. iotest 296 must now expect them in x-blockdev-amend's QMP reply instead of waiting for the actual job to fail later. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20220209105452.1694545-2-eesposit@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220304153729.711387-6-hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-02-09 13:54:48 +03:00
.clean = blockdev_amend_clean,
};
void qmp_x_blockdev_amend(const char *job_id,
const char *node_name,
BlockdevAmendOptions *options,
bool has_force,
bool force,
Error **errp)
{
BlockdevAmendJob *s;
const char *fmt = BlockdevDriver_str(options->driver);
BlockDriver *drv = bdrv_find_format(fmt);
BlockDriverState *bs;
bs = bdrv_lookup_bs(NULL, node_name, errp);
if (!bs) {
return;
}
if (!drv) {
error_setg(errp, "Block driver '%s' not found or not supported", fmt);
return;
}
/*
* If the driver is in the schema, we know that it exists. But it may not
* be whitelisted.
*/
if (bdrv_uses_whitelist() && !bdrv_is_whitelisted(drv, false)) {
error_setg(errp, "Driver is not whitelisted");
return;
}
if (bs->drv != drv) {
error_setg(errp,
"x-blockdev-amend doesn't support changing the block driver");
return;
}
/* Error out if the driver doesn't support .bdrv_co_amend */
if (!drv->bdrv_co_amend) {
error_setg(errp, "Driver does not support x-blockdev-amend");
return;
}
/* Create the block job */
s = job_create(job_id, &blockdev_amend_job_driver, NULL,
bdrv_get_aio_context(bs), JOB_DEFAULT | JOB_MANUAL_DISMISS,
NULL, NULL, errp);
if (!s) {
return;
}
s->bs = bs,
s->opts = QAPI_CLONE(BlockdevAmendOptions, options),
s->force = has_force ? force : false;
crypto: perform permission checks under BQL Move the permission API calls into driver-specific callbacks that always run under BQL. In this case, bdrv_crypto_luks needs to perform permission checks before and after qcrypto_block_amend_options(). The problem is that the caller, block_crypto_amend_options_generic_luks(), can also run in I/O from .bdrv_co_amend(). This does not comply with Global State-I/O API split, as permissions API must always run under BQL. Firstly, introduce .bdrv_amend_pre_run() and .bdrv_amend_clean() callbacks. These two callbacks are guaranteed to be invoked under BQL, respectively before and after .bdrv_co_amend(). They take care of performing the permission checks in the same way as they are currently done before and after qcrypto_block_amend_options(). These callbacks are in preparation for next patch, where we delete the original permission check. Right now they just add redundant control. Then, call .bdrv_amend_pre_run() before job_start in qmp_x_blockdev_amend(), so that it will be run before the job coroutine is created and stay in the main loop. As a cleanup, use JobDriver's .clean() callback to call .bdrv_amend_clean(), and run amend-specific cleanup callbacks under BQL. After this patch, permission failures occur early in the blockdev-amend job to update a LUKS volume's keys. iotest 296 must now expect them in x-blockdev-amend's QMP reply instead of waiting for the actual job to fail later. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20220209105452.1694545-2-eesposit@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220304153729.711387-6-hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-02-09 13:54:48 +03:00
if (blockdev_amend_pre_run(s, errp)) {
job_early_fail(&s->common);
return;
}
job_start(&s->common);
}