core: add io controller support on the unified hierarchy

On the unified hierarchy, blkio controller is renamed to io and the interface
is changed significantly.

* blkio.weight and blkio.weight_device are consolidated into io.weight which
  uses the standardized weight range [1, 10000] with 100 as the default value.

* blkio.throttle.{read|write}_{bps|iops}_device are consolidated into io.max.
  Expansion of throttling features is being worked on to support
  work-conserving absolute limits (io.low and io.high).

* All stats are consolidated into io.stats.

This patchset adds support for the new interface.  As the interface has been
revamped and new features are expected to be added, it seems best to treat it
as a separate controller rather than trying to expand the blkio settings
although we might add automatic translation if only blkio settings are
specified.

* io.weight handling is mostly identical to blkio.weight[_device] handling
  except that the weight range is different.

* Both read and write bandwidth settings are consolidated into
  CGroupIODeviceLimit which describes all limits applicable to the device.
  This makes it less painful to add new limits.

* "max" can be used to specify the maximum limit which is equivalent to no
  config for max limits and treated as such.  If a given CGroupIODeviceLimit
  doesn't contain any non-default configs, the config struct is discarded once
  the no limit config is applied to cgroup.

* lookup_blkio_device() is renamed to lookup_block_device().

Signed-off-by: Tejun Heo <htejun@fb.com>

1 files changed, 308 insertions, 0 deletions

diff --git a/src/core/dbus-cgroup.c b/src/core/dbus-cgroup.c
index 859d155ec1..a2a4a6249c 100644
--- a/src/core/dbus-cgroup.c
+++ b/src/core/dbus-cgroup.c
@@ -28,6 +28,76 @@
 
 static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_cgroup_device_policy, cgroup_device_policy, CGroupDevicePolicy);
 
+static int property_get_io_device_weight(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        CGroupContext *c = userdata;
+        CGroupIODeviceWeight *w;
+        int r;
+
+        assert(bus);
+        assert(reply);
+        assert(c);
+
+        r = sd_bus_message_open_container(reply, 'a', "(st)");
+        if (r < 0)
+                return r;
+
+        LIST_FOREACH(device_weights, w, c->io_device_weights) {
+                r = sd_bus_message_append(reply, "(st)", w->path, w->weight);
+                if (r < 0)
+                        return r;
+        }
+
+        return sd_bus_message_close_container(reply);
+}
+
+static int property_get_io_device_limits(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        CGroupContext *c = userdata;
+        CGroupIODeviceLimit *l;
+        int r;
+
+        assert(bus);
+        assert(reply);
+        assert(c);
+
+        r = sd_bus_message_open_container(reply, 'a', "(st)");
+        if (r < 0)
+                return r;
+
+        LIST_FOREACH(device_limits, l, c->io_device_limits) {
+                uint64_t v;
+
+                if (streq(property, "IOReadBandwidthMax"))
+                        v = l->rbps_max;
+                else
+                        v = l->wbps_max;
+
+                if (v == CGROUP_LIMIT_MAX)
+                        continue;
+
+                r = sd_bus_message_append(reply, "(st)", l->path, v);
+                if (r < 0)
+                        return r;
+        }
+
+        return sd_bus_message_close_container(reply);
+}
+
 static int property_get_blockio_device_weight(
                 sd_bus *bus,
                 const char *path,
@@ -141,6 +211,12 @@ const sd_bus_vtable bus_cgroup_vtable[] = {
         SD_BUS_PROPERTY("CPUShares", "t", NULL, offsetof(CGroupContext, cpu_shares), 0),
         SD_BUS_PROPERTY("StartupCPUShares", "t", NULL, offsetof(CGroupContext, startup_cpu_shares), 0),
         SD_BUS_PROPERTY("CPUQuotaPerSecUSec", "t", bus_property_get_usec, offsetof(CGroupContext, cpu_quota_per_sec_usec), 0),
+        SD_BUS_PROPERTY("IOAccounting", "b", bus_property_get_bool, offsetof(CGroupContext, io_accounting), 0),
+        SD_BUS_PROPERTY("IOWeight", "t", NULL, offsetof(CGroupContext, io_weight), 0),
+        SD_BUS_PROPERTY("StartupIOWeight", "t", NULL, offsetof(CGroupContext, startup_io_weight), 0),
+        SD_BUS_PROPERTY("IODeviceWeight", "a(st)", property_get_io_device_weight, 0, 0),
+        SD_BUS_PROPERTY("IOReadBandwidthMax", "a(st)", property_get_io_device_limits, 0, 0),
+        SD_BUS_PROPERTY("IOWriteBandwidthMax", "a(st)", property_get_io_device_limits, 0, 0),
         SD_BUS_PROPERTY("BlockIOAccounting", "b", bus_property_get_bool, offsetof(CGroupContext, blockio_accounting), 0),
         SD_BUS_PROPERTY("BlockIOWeight", "t", NULL, offsetof(CGroupContext, blockio_weight), 0),
         SD_BUS_PROPERTY("StartupBlockIOWeight", "t", NULL, offsetof(CGroupContext, startup_blockio_weight), 0),
@@ -281,6 +357,238 @@ int bus_cgroup_set_property(
 
                 return 1;
 
+        } else if (streq(name, "IOAccounting")) {
+                int b;
+
+                r = sd_bus_message_read(message, "b", &b);
+                if (r < 0)
+                        return r;
+
+                if (mode != UNIT_CHECK) {
+                        c->io_accounting = b;
+                        unit_invalidate_cgroup(u, CGROUP_MASK_IO);
+                        unit_write_drop_in_private(u, mode, name, b ? "IOAccounting=yes" : "IOAccounting=no");
+                }
+
+                return 1;
+
+        } else if (streq(name, "IOWeight")) {
+                uint64_t weight;
+
+                r = sd_bus_message_read(message, "t", &weight);
+                if (r < 0)
+                        return r;
+
+                if (!CGROUP_WEIGHT_IS_OK(weight))
+                        return sd_bus_error_set_errnof(error, EINVAL, "IOWeight value out of range");
+
+                if (mode != UNIT_CHECK) {
+                        c->io_weight = weight;
+                        unit_invalidate_cgroup(u, CGROUP_MASK_IO);
+
+                        if (weight == CGROUP_WEIGHT_INVALID)
+                                unit_write_drop_in_private(u, mode, name, "IOWeight=");
+                        else
+                                unit_write_drop_in_private_format(u, mode, name, "IOWeight=%" PRIu64, weight);
+                }
+
+                return 1;
+
+        } else if (streq(name, "StartupIOWeight")) {
+                uint64_t weight;
+
+                r = sd_bus_message_read(message, "t", &weight);
+                if (r < 0)
+                        return r;
+
+                if (CGROUP_WEIGHT_IS_OK(weight))
+                        return sd_bus_error_set_errnof(error, EINVAL, "StartupIOWeight value out of range");
+
+                if (mode != UNIT_CHECK) {
+                        c->startup_io_weight = weight;
+                        unit_invalidate_cgroup(u, CGROUP_MASK_IO);
+
+                        if (weight == CGROUP_WEIGHT_INVALID)
+                                unit_write_drop_in_private(u, mode, name, "StartupIOWeight=");
+                        else
+                                unit_write_drop_in_private_format(u, mode, name, "StartupIOWeight=%" PRIu64, weight);
+                }
+
+                return 1;
+
+        } else if (streq(name, "IOReadBandwidthMax") || streq(name, "IOWriteBandwidthMax")) {
+                const char *path;
+                bool read = true;
+                unsigned n = 0;
+                uint64_t u64;
+
+                if (streq(name, "IOWriteBandwidthMax"))
+                        read = false;
+
+                r = sd_bus_message_enter_container(message, 'a', "(st)");
+                if (r < 0)
+                        return r;
+
+                while ((r = sd_bus_message_read(message, "(st)", &path, &u64)) > 0) {
+
+                        if (mode != UNIT_CHECK) {
+                                CGroupIODeviceLimit *a = NULL, *b;
+
+                                LIST_FOREACH(device_limits, b, c->io_device_limits) {
+                                        if (path_equal(path, b->path)) {
+                                                a = b;
+                                                break;
+                                        }
+                                }
+
+                                if (!a) {
+                                        a = new0(CGroupIODeviceLimit, 1);
+                                        if (!a)
+                                                return -ENOMEM;
+
+                                        a->path = strdup(path);
+                                        if (!a->path) {
+                                                free(a);
+                                                return -ENOMEM;
+                                        }
+
+                                        a->rbps_max = CGROUP_LIMIT_MAX;
+                                        a->wbps_max = CGROUP_LIMIT_MAX;
+
+                                        LIST_PREPEND(device_limits, c->io_device_limits, a);
+                                }
+
+                                if (read)
+                                        a->rbps_max = u64;
+                                else
+                                        a->wbps_max = u64;
+                        }
+
+                        n++;
+                }
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_exit_container(message);
+                if (r < 0)
+                        return r;
+
+                if (mode != UNIT_CHECK) {
+                        CGroupIODeviceLimit *a;
+                        _cleanup_free_ char *buf = NULL;
+                        _cleanup_fclose_ FILE *f = NULL;
+                        size_t size = 0;
+
+                        if (n == 0) {
+                                LIST_FOREACH(device_limits, a, c->io_device_limits)
+                                        if (read)
+                                                a->rbps_max = CGROUP_LIMIT_MAX;
+                                        else
+                                                a->wbps_max = CGROUP_LIMIT_MAX;
+                        }
+
+                        unit_invalidate_cgroup(u, CGROUP_MASK_IO);
+
+                        f = open_memstream(&buf, &size);
+                        if (!f)
+                                return -ENOMEM;
+
+                        if (read) {
+                                fputs("IOReadBandwidthMax=\n", f);
+                                LIST_FOREACH(device_limits, a, c->io_device_limits)
+                                        if (a->rbps_max != CGROUP_LIMIT_MAX)
+                                                fprintf(f, "IOReadBandwidthMax=%s %" PRIu64 "\n", a->path, a->rbps_max);
+                        } else {
+                                fputs("IOWriteBandwidthMax=\n", f);
+                                LIST_FOREACH(device_limits, a, c->io_device_limits)
+                                        if (a->wbps_max != CGROUP_LIMIT_MAX)
+                                                fprintf(f, "IOWriteBandwidthMax=%s %" PRIu64 "\n", a->path, a->wbps_max);
+                        }
+
+                        r = fflush_and_check(f);
+                        if (r < 0)
+                                return r;
+                        unit_write_drop_in_private(u, mode, name, buf);
+                }
+
+                return 1;
+
+        } else if (streq(name, "IODeviceWeight")) {
+                const char *path;
+                uint64_t weight;
+                unsigned n = 0;
+
+                r = sd_bus_message_enter_container(message, 'a', "(st)");
+                if (r < 0)
+                        return r;
+
+                while ((r = sd_bus_message_read(message, "(st)", &path, &weight)) > 0) {
+
+                        if (!CGROUP_WEIGHT_IS_OK(weight) || weight == CGROUP_WEIGHT_INVALID)
+                                return sd_bus_error_set_errnof(error, EINVAL, "IODeviceWeight out of range");
+
+                        if (mode != UNIT_CHECK) {
+                                CGroupIODeviceWeight *a = NULL, *b;
+
+                                LIST_FOREACH(device_weights, b, c->io_device_weights) {
+                                        if (path_equal(b->path, path)) {
+                                                a = b;
+                                                break;
+                                        }
+                                }
+
+                                if (!a) {
+                                        a = new0(CGroupIODeviceWeight, 1);
+                                        if (!a)
+                                                return -ENOMEM;
+
+                                        a->path = strdup(path);
+                                        if (!a->path) {
+                                                free(a);
+                                                return -ENOMEM;
+                                        }
+                                        LIST_PREPEND(device_weights,c->io_device_weights, a);
+                                }
+
+                                a->weight = weight;
+                        }
+
+                        n++;
+                }
+
+                r = sd_bus_message_exit_container(message);
+                if (r < 0)
+                        return r;
+
+                if (mode != UNIT_CHECK) {
+                        _cleanup_free_ char *buf = NULL;
+                        _cleanup_fclose_ FILE *f = NULL;
+                        CGroupIODeviceWeight *a;
+                        size_t size = 0;
+
+                        if (n == 0) {
+                                while (c->io_device_weights)
+                                        cgroup_context_free_io_device_weight(c, c->io_device_weights);
+                        }
+
+                        unit_invalidate_cgroup(u, CGROUP_MASK_IO);
+
+                        f = open_memstream(&buf, &size);
+                        if (!f)
+                                return -ENOMEM;
+
+                        fputs("IODeviceWeight=\n", f);
+                        LIST_FOREACH(device_weights, a, c->io_device_weights)
+                                fprintf(f, "IODeviceWeight=%s %" PRIu64 "\n", a->path, a->weight);
+
+                        r = fflush_and_check(f);
+                        if (r < 0)
+                                return r;
+                        unit_write_drop_in_private(u, mode, name, buf);
+                }
+
+                return 1;
+
         } else if (streq(name, "BlockIOAccounting")) {
                 int b;