diff options
Diffstat (limited to 'block/throttle.c')
| -rw-r--r-- | block/throttle.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/block/throttle.c b/block/throttle.c new file mode 100644 index 0000000000..5bca76300f --- /dev/null +++ b/block/throttle.c @@ -0,0 +1,237 @@ +/* + * 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/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 */ } + }, +}; + +static int throttle_configure_tgm(BlockDriverState *bs, + ThrottleGroupMember *tgm, + QDict *options, Error **errp) +{ + int ret; + const char *group_name; + Error *local_err = NULL; + QemuOpts *opts = qemu_opts_create(&throttle_opts, NULL, 0, &error_abort); + + qemu_opts_absorb_qdict(opts, options, &local_err); + if (local_err) { + error_propagate(errp, local_err); + 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; + } + + /* Register membership to group with name group_name */ + throttle_group_register_tgm(tgm, group_name, bdrv_get_aio_context(bs)); + 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; + + bs->file = bdrv_open_child(NULL, options, "file", bs, + &child_file, false, errp); + if (!bs->file) { + return -EINVAL; + } + bs->supported_write_flags = bs->file->bs->supported_write_flags; + bs->supported_zero_flags = bs->file->bs->supported_zero_flags; + + return throttle_configure_tgm(bs, tgm, options, errp); +} + +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, + uint64_t offset, uint64_t bytes, + QEMUIOVector *qiov, int 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, + uint64_t offset, uint64_t bytes, + QEMUIOVector *qiov, int 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, int 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, int bytes) +{ + ThrottleGroupMember *tgm = bs->opaque; + throttle_group_co_io_limits_intercept(tgm, bytes, true); + + return bdrv_co_pdiscard(bs->file->bs, offset, bytes); +} + +static int 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) +{ + ThrottleGroupMember *tgm; + + assert(reopen_state != NULL); + assert(reopen_state->bs != NULL); + + reopen_state->opaque = g_new0(ThrottleGroupMember, 1); + tgm = reopen_state->opaque; + + return throttle_configure_tgm(reopen_state->bs, tgm, reopen_state->options, + errp); +} + +static void throttle_reopen_commit(BDRVReopenState *reopen_state) +{ + ThrottleGroupMember *old_tgm = reopen_state->bs->opaque; + ThrottleGroupMember *new_tgm = reopen_state->opaque; + + throttle_group_unregister_tgm(old_tgm); + g_free(old_tgm); + reopen_state->bs->opaque = new_tgm; + reopen_state->opaque = NULL; +} + +static void throttle_reopen_abort(BDRVReopenState *reopen_state) +{ + ThrottleGroupMember *tgm = reopen_state->opaque; + + throttle_group_unregister_tgm(tgm); + g_free(tgm); + reopen_state->opaque = NULL; +} + +static bool throttle_recurse_is_first_non_filter(BlockDriverState *bs, + BlockDriverState *candidate) +{ + return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate); +} + +static BlockDriver bdrv_throttle = { + .format_name = "throttle", + .protocol_name = "throttle", + .instance_size = sizeof(ThrottleGroupMember), + + .bdrv_file_open = throttle_open, + .bdrv_close = throttle_close, + .bdrv_co_flush = throttle_co_flush, + + .bdrv_child_perm = bdrv_filter_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_recurse_is_first_non_filter = throttle_recurse_is_first_non_filter, + + .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_get_block_status = bdrv_co_get_block_status_from_file, + + .is_filter = true, +}; + +static void bdrv_throttle_init(void) +{ + bdrv_register(&bdrv_throttle); +} + +block_init(bdrv_throttle_init); |