block/throttle.c uses existing I/O throttle infrastructure inside a
block filter driver. I/O operations are intercepted in the filter's
read/write coroutines, and referred to block/throttle-groups.c
The driver can be used with the syntax
-drive driver=throttle,file.filename=foo.qcow2,throttle-group=bar
which registers the throttle filter node with the ThrottleGroup 'bar'. The
given group must be created beforehand with object-add or -object.
Signed-off-by: Manos Pitsidianakis <el13...@mail.ntua.gr>
---
qapi/block-core.json | 18 ++-
include/block/throttle-groups.h | 1 +
include/qemu/throttle-options.h | 1 +
block/throttle-groups.c | 7 +-
block/throttle.c | 250 ++++++++++++++++++++++++++++++++++++++++
block/Makefile.objs | 1 +
6 files changed, 276 insertions(+), 2 deletions(-)
create mode 100644 block/throttle.c
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 0bdc69aa5f..405c181954 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2222,6 +2222,7 @@
# Drivers that are supported in block device operations.
#
# @vxhs: Since 2.10
+# @throttle: Since 2.11
#
# Since: 2.9
##
@@ -2231,7 +2232,7 @@
'host_device', 'http', 'https', 'iscsi', 'luks', 'nbd', 'nfs',
'null-aio', 'null-co', 'parallels', 'qcow', 'qcow2', 'qed',
'quorum', 'raw', 'rbd', 'replication', 'sheepdog', 'ssh',
- 'vdi', 'vhdx', 'vmdk', 'vpc', 'vvfat', 'vxhs' ] }
+ 'throttle', 'vdi', 'vhdx', 'vmdk', 'vpc', 'vvfat', 'vxhs' ] }
##
# @BlockdevOptionsFile:
@@ -3095,6 +3096,20 @@
'*tls-creds': 'str' } }
##
+# @BlockdevOptionsThrottle:
+#
+# Driver specific block device options for the throttle driver
+#
+# @throttle-group: the name of the throttle-group object to use. It
+# must already exist.
+# @file: reference to or definition of the data source block device
+# Since: 2.11
+##
+{ 'struct': 'BlockdevOptionsThrottle',
+ 'data': { '*throttle-group': 'str',
+ 'file' : 'BlockdevRef'
+ } }
+##
# @BlockdevOptions:
#
# Options for creating a block device. Many options are available for all
@@ -3155,6 +3170,7 @@
'replication':'BlockdevOptionsReplication',
'sheepdog': 'BlockdevOptionsSheepdog',
'ssh': 'BlockdevOptionsSsh',
+ 'throttle': 'BlockdevOptionsThrottle',
'vdi': 'BlockdevOptionsGenericFormat',
'vhdx': 'BlockdevOptionsGenericFormat',
'vmdk': 'BlockdevOptionsGenericCOWFormat',
diff --git a/include/block/throttle-groups.h b/include/block/throttle-groups.h
index 82f030523f..ec969e84fe 100644
--- a/include/block/throttle-groups.h
+++ b/include/block/throttle-groups.h
@@ -76,5 +76,6 @@ void coroutine_fn
throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm
void throttle_group_attach_aio_context(ThrottleGroupMember *tgm,
AioContext *new_context);
void throttle_group_detach_aio_context(ThrottleGroupMember *tgm);
+bool throttle_group_exists(const char *name);
#endif
diff --git a/include/qemu/throttle-options.h b/include/qemu/throttle-options.h
index 182b7896e1..3528a8f4a2 100644
--- a/include/qemu/throttle-options.h
+++ b/include/qemu/throttle-options.h
@@ -29,6 +29,7 @@
#define QEMU_OPT_BPS_WRITE_MAX "bps-write-max"
#define QEMU_OPT_BPS_WRITE_MAX_LENGTH "bps-write-max-length"
#define QEMU_OPT_IOPS_SIZE "iops-size"
+#define QEMU_OPT_THROTTLE_GROUP_NAME "throttle-group"
#define THROTTLE_OPT_PREFIX "throttling."
#define THROTTLE_OPTS \
diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index a4268a954e..4b483a16d4 100644
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -101,7 +101,7 @@ static ThrottleGroup *throttle_group_by_name(const char
*name)
return NULL;
}
-static bool throttle_group_exists(const char *name)
+bool throttle_group_exists(const char *name)
{
return throttle_group_by_name(name) ? true : false;
}
@@ -548,6 +548,11 @@ void throttle_group_unregister_tgm(ThrottleGroupMember
*tgm)
ThrottleGroupMember *token;
int i;
+ if (!ts) {
+ /* Discard uninitialized tgm */
+ return;
+ }
+
assert(tgm->pending_reqs[0] == 0 && tgm->pending_reqs[1] == 0);
assert(qemu_co_queue_empty(&tgm->throttled_reqs[0]));
assert(qemu_co_queue_empty(&tgm->throttled_reqs[1]));
diff --git a/block/throttle.c b/block/throttle.c
new file mode 100644
index 0000000000..910de27dcd
--- /dev/null
+++ b/block/throttle.c
@@ -0,0 +1,250 @@
+/*
+ * 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 int64_t coroutine_fn throttle_co_get_block_status(BlockDriverState *bs,
+ int64_t sector_num,
+ int nb_sectors,
+ int *pnum,
+ BlockDriverState
**file)
+{
+ assert(bs->file && bs->file->bs);
+ *pnum = nb_sectors;
+ *file = bs->file->bs;
+ return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
+ (sector_num << BDRV_SECTOR_BITS);
+}
+
+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 = throttle_co_get_block_status,
+
+ .is_filter = true,
+};
+
+static void bdrv_throttle_init(void)
+{
+ bdrv_register(&bdrv_throttle);
+}
+
+block_init(bdrv_throttle_init);
diff --git a/block/Makefile.objs b/block/Makefile.objs
index 2aaede4ae1..6eaf78a046 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -25,6 +25,7 @@ block-obj-y += accounting.o dirty-bitmap.o
block-obj-y += write-threshold.o
block-obj-y += backup.o
block-obj-$(CONFIG_REPLICATION) += replication.o
+block-obj-y += throttle.o
block-obj-y += crypto.o
--
2.11.0
