277 lines
8.6 KiB
C
277 lines
8.6 KiB
C
/*
|
|
* QEMU block throttling filter driver infrastructure
|
|
*
|
|
* Copyright (c) 2017 Manos Pitsidianakis
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation; either version 2 or
|
|
* (at your option) version 3 of the License.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "block/throttle-groups.h"
|
|
#include "qemu/module.h"
|
|
#include "qemu/option.h"
|
|
#include "qemu/throttle-options.h"
|
|
#include "qapi/error.h"
|
|
|
|
static QemuOptsList throttle_opts = {
|
|
.name = "throttle",
|
|
.head = QTAILQ_HEAD_INITIALIZER(throttle_opts.head),
|
|
.desc = {
|
|
{
|
|
.name = QEMU_OPT_THROTTLE_GROUP_NAME,
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "Name of the throttle group",
|
|
},
|
|
{ /* end of list */ }
|
|
},
|
|
};
|
|
|
|
/*
|
|
* If this function succeeds then the throttle group name is stored in
|
|
* @group and must be freed by the caller.
|
|
* If there's an error then @group remains unmodified.
|
|
*/
|
|
static int throttle_parse_options(QDict *options, char **group, Error **errp)
|
|
{
|
|
int ret;
|
|
const char *group_name;
|
|
QemuOpts *opts = qemu_opts_create(&throttle_opts, NULL, 0, &error_abort);
|
|
|
|
if (!qemu_opts_absorb_qdict(opts, options, errp)) {
|
|
ret = -EINVAL;
|
|
goto fin;
|
|
}
|
|
|
|
group_name = qemu_opt_get(opts, QEMU_OPT_THROTTLE_GROUP_NAME);
|
|
if (!group_name) {
|
|
error_setg(errp, "Please specify a throttle group");
|
|
ret = -EINVAL;
|
|
goto fin;
|
|
} else if (!throttle_group_exists(group_name)) {
|
|
error_setg(errp, "Throttle group '%s' does not exist", group_name);
|
|
ret = -EINVAL;
|
|
goto fin;
|
|
}
|
|
|
|
*group = g_strdup(group_name);
|
|
ret = 0;
|
|
fin:
|
|
qemu_opts_del(opts);
|
|
return ret;
|
|
}
|
|
|
|
static int throttle_open(BlockDriverState *bs, QDict *options,
|
|
int flags, Error **errp)
|
|
{
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
char *group;
|
|
int ret;
|
|
|
|
ret = bdrv_open_file_child(NULL, options, "file", bs, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
bs->supported_write_flags = bs->file->bs->supported_write_flags |
|
|
BDRV_REQ_WRITE_UNCHANGED;
|
|
bs->supported_zero_flags = bs->file->bs->supported_zero_flags |
|
|
BDRV_REQ_WRITE_UNCHANGED;
|
|
|
|
ret = throttle_parse_options(options, &group, errp);
|
|
if (ret == 0) {
|
|
/* Register membership to group with name group_name */
|
|
throttle_group_register_tgm(tgm, group, bdrv_get_aio_context(bs));
|
|
g_free(group);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void throttle_close(BlockDriverState *bs)
|
|
{
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
throttle_group_unregister_tgm(tgm);
|
|
}
|
|
|
|
|
|
static int64_t throttle_getlength(BlockDriverState *bs)
|
|
{
|
|
return bdrv_getlength(bs->file->bs);
|
|
}
|
|
|
|
static int coroutine_fn throttle_co_preadv(BlockDriverState *bs,
|
|
int64_t offset, int64_t bytes,
|
|
QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
throttle_group_co_io_limits_intercept(tgm, bytes, false);
|
|
|
|
return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
|
|
}
|
|
|
|
static int coroutine_fn throttle_co_pwritev(BlockDriverState *bs,
|
|
int64_t offset, int64_t bytes,
|
|
QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
throttle_group_co_io_limits_intercept(tgm, bytes, true);
|
|
|
|
return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
|
|
}
|
|
|
|
static int coroutine_fn throttle_co_pwrite_zeroes(BlockDriverState *bs,
|
|
int64_t offset, int64_t bytes,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
throttle_group_co_io_limits_intercept(tgm, bytes, true);
|
|
|
|
return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
|
|
}
|
|
|
|
static int coroutine_fn throttle_co_pdiscard(BlockDriverState *bs,
|
|
int64_t offset, int64_t bytes)
|
|
{
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
throttle_group_co_io_limits_intercept(tgm, bytes, true);
|
|
|
|
return bdrv_co_pdiscard(bs->file, offset, bytes);
|
|
}
|
|
|
|
static int coroutine_fn throttle_co_pwritev_compressed(BlockDriverState *bs,
|
|
int64_t offset,
|
|
int64_t bytes,
|
|
QEMUIOVector *qiov)
|
|
{
|
|
return throttle_co_pwritev(bs, offset, bytes, qiov,
|
|
BDRV_REQ_WRITE_COMPRESSED);
|
|
}
|
|
|
|
static int coroutine_fn throttle_co_flush(BlockDriverState *bs)
|
|
{
|
|
return bdrv_co_flush(bs->file->bs);
|
|
}
|
|
|
|
static void throttle_detach_aio_context(BlockDriverState *bs)
|
|
{
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
throttle_group_detach_aio_context(tgm);
|
|
}
|
|
|
|
static void throttle_attach_aio_context(BlockDriverState *bs,
|
|
AioContext *new_context)
|
|
{
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
throttle_group_attach_aio_context(tgm, new_context);
|
|
}
|
|
|
|
static int throttle_reopen_prepare(BDRVReopenState *reopen_state,
|
|
BlockReopenQueue *queue, Error **errp)
|
|
{
|
|
int ret;
|
|
char *group = NULL;
|
|
|
|
assert(reopen_state != NULL);
|
|
assert(reopen_state->bs != NULL);
|
|
|
|
ret = throttle_parse_options(reopen_state->options, &group, errp);
|
|
reopen_state->opaque = group;
|
|
return ret;
|
|
}
|
|
|
|
static void throttle_reopen_commit(BDRVReopenState *reopen_state)
|
|
{
|
|
BlockDriverState *bs = reopen_state->bs;
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
char *group = reopen_state->opaque;
|
|
|
|
assert(group);
|
|
|
|
if (strcmp(group, throttle_group_get_name(tgm))) {
|
|
throttle_group_unregister_tgm(tgm);
|
|
throttle_group_register_tgm(tgm, group, bdrv_get_aio_context(bs));
|
|
}
|
|
g_free(reopen_state->opaque);
|
|
reopen_state->opaque = NULL;
|
|
}
|
|
|
|
static void throttle_reopen_abort(BDRVReopenState *reopen_state)
|
|
{
|
|
g_free(reopen_state->opaque);
|
|
reopen_state->opaque = NULL;
|
|
}
|
|
|
|
static void coroutine_fn throttle_co_drain_begin(BlockDriverState *bs)
|
|
{
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
if (qatomic_fetch_inc(&tgm->io_limits_disabled) == 0) {
|
|
throttle_group_restart_tgm(tgm);
|
|
}
|
|
}
|
|
|
|
static void coroutine_fn throttle_co_drain_end(BlockDriverState *bs)
|
|
{
|
|
ThrottleGroupMember *tgm = bs->opaque;
|
|
assert(tgm->io_limits_disabled);
|
|
qatomic_dec(&tgm->io_limits_disabled);
|
|
}
|
|
|
|
static const char *const throttle_strong_runtime_opts[] = {
|
|
QEMU_OPT_THROTTLE_GROUP_NAME,
|
|
|
|
NULL
|
|
};
|
|
|
|
static BlockDriver bdrv_throttle = {
|
|
.format_name = "throttle",
|
|
.instance_size = sizeof(ThrottleGroupMember),
|
|
|
|
.bdrv_open = throttle_open,
|
|
.bdrv_close = throttle_close,
|
|
.bdrv_co_flush = throttle_co_flush,
|
|
|
|
.bdrv_child_perm = bdrv_default_perms,
|
|
|
|
.bdrv_getlength = throttle_getlength,
|
|
|
|
.bdrv_co_preadv = throttle_co_preadv,
|
|
.bdrv_co_pwritev = throttle_co_pwritev,
|
|
|
|
.bdrv_co_pwrite_zeroes = throttle_co_pwrite_zeroes,
|
|
.bdrv_co_pdiscard = throttle_co_pdiscard,
|
|
.bdrv_co_pwritev_compressed = throttle_co_pwritev_compressed,
|
|
|
|
.bdrv_attach_aio_context = throttle_attach_aio_context,
|
|
.bdrv_detach_aio_context = throttle_detach_aio_context,
|
|
|
|
.bdrv_reopen_prepare = throttle_reopen_prepare,
|
|
.bdrv_reopen_commit = throttle_reopen_commit,
|
|
.bdrv_reopen_abort = throttle_reopen_abort,
|
|
|
|
.bdrv_co_drain_begin = throttle_co_drain_begin,
|
|
.bdrv_co_drain_end = throttle_co_drain_end,
|
|
|
|
.is_filter = true,
|
|
.strong_runtime_opts = throttle_strong_runtime_opts,
|
|
};
|
|
|
|
static void bdrv_throttle_init(void)
|
|
{
|
|
bdrv_register(&bdrv_throttle);
|
|
}
|
|
|
|
block_init(bdrv_throttle_init);
|