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-rw-r--r--block/Makefile.objs1
-rw-r--r--block/throttle-groups.c15
-rw-r--r--block/throttle.c237
3 files changed, 252 insertions, 1 deletions
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
diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index ed1817ec84..6ba992c8d7 100644
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -101,6 +101,14 @@ static ThrottleGroup *throttle_group_by_name(const char *name)
return NULL;
}
+/* This function reads throttle_groups and must be called under the global
+ * mutex.
+ */
+bool throttle_group_exists(const char *name)
+{
+ return throttle_group_by_name(name) != NULL;
+}
+
/* Increments the reference count of a ThrottleGroup given its name.
*
* If no ThrottleGroup is found with the given name a new one is
@@ -543,6 +551,11 @@ void throttle_group_unregister_tgm(ThrottleGroupMember *tgm)
ThrottleGroupMember *token;
int i;
+ if (!ts) {
+ /* Discard already unregistered 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]));
@@ -709,7 +722,7 @@ static void throttle_group_obj_complete(UserCreatable *obj, Error **errp)
assert(tg->name);
/* error if name is duplicate */
- if (throttle_group_by_name(tg->name) != NULL) {
+ if (throttle_group_exists(tg->name)) {
error_setg(errp, "A group with this name already exists");
return;
}
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);