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>

10 files changed, 686 insertions, 4 deletions

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 25cc6962f9..44106e52ea 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -32,6 +32,7 @@
 #include "special.h"
 #include "string-table.h"
 #include "string-util.h"
+#include "stdio-util.h"
 
 #define CGROUP_CPU_QUOTA_PERIOD_USEC ((usec_t) 100 * USEC_PER_MSEC)
 
@@ -47,6 +48,9 @@ void cgroup_context_init(CGroupContext *c) {
 
         c->memory_limit = (uint64_t) -1;
 
+        c->io_weight = CGROUP_WEIGHT_INVALID;
+        c->startup_io_weight = CGROUP_WEIGHT_INVALID;
+
         c->blockio_weight = CGROUP_BLKIO_WEIGHT_INVALID;
         c->startup_blockio_weight = CGROUP_BLKIO_WEIGHT_INVALID;
 
@@ -62,6 +66,24 @@ void cgroup_context_free_device_allow(CGroupContext *c, CGroupDeviceAllow *a) {
         free(a);
 }
 
+void cgroup_context_free_io_device_weight(CGroupContext *c, CGroupIODeviceWeight *w) {
+        assert(c);
+        assert(w);
+
+        LIST_REMOVE(device_weights, c->io_device_weights, w);
+        free(w->path);
+        free(w);
+}
+
+void cgroup_context_free_io_device_limit(CGroupContext *c, CGroupIODeviceLimit *l) {
+        assert(c);
+        assert(l);
+
+        LIST_REMOVE(device_limits, c->io_device_limits, l);
+        free(l->path);
+        free(l);
+}
+
 void cgroup_context_free_blockio_device_weight(CGroupContext *c, CGroupBlockIODeviceWeight *w) {
         assert(c);
         assert(w);
@@ -83,6 +105,12 @@ void cgroup_context_free_blockio_device_bandwidth(CGroupContext *c, CGroupBlockI
 void cgroup_context_done(CGroupContext *c) {
         assert(c);
 
+        while (c->io_device_weights)
+                cgroup_context_free_io_device_weight(c, c->io_device_weights);
+
+        while (c->io_device_limits)
+                cgroup_context_free_io_device_limit(c, c->io_device_limits);
+
         while (c->blockio_device_weights)
                 cgroup_context_free_blockio_device_weight(c, c->blockio_device_weights);
 
@@ -94,6 +122,8 @@ void cgroup_context_done(CGroupContext *c) {
 }
 
 void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
+        CGroupIODeviceLimit *il;
+        CGroupIODeviceWeight *iw;
         CGroupBlockIODeviceBandwidth *b;
         CGroupBlockIODeviceWeight *w;
         CGroupDeviceAllow *a;
@@ -106,12 +136,15 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
 
         fprintf(f,
                 "%sCPUAccounting=%s\n"
+                "%sIOAccounting=%s\n"
                 "%sBlockIOAccounting=%s\n"
                 "%sMemoryAccounting=%s\n"
                 "%sTasksAccounting=%s\n"
                 "%sCPUShares=%" PRIu64 "\n"
                 "%sStartupCPUShares=%" PRIu64 "\n"
                 "%sCPUQuotaPerSecSec=%s\n"
+                "%sIOWeight=%" PRIu64 "\n"
+                "%sStartupIOWeight=%" PRIu64 "\n"
                 "%sBlockIOWeight=%" PRIu64 "\n"
                 "%sStartupBlockIOWeight=%" PRIu64 "\n"
                 "%sMemoryLimit=%" PRIu64 "\n"
@@ -119,12 +152,15 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
                 "%sDevicePolicy=%s\n"
                 "%sDelegate=%s\n",
                 prefix, yes_no(c->cpu_accounting),
+                prefix, yes_no(c->io_accounting),
                 prefix, yes_no(c->blockio_accounting),
                 prefix, yes_no(c->memory_accounting),
                 prefix, yes_no(c->tasks_accounting),
                 prefix, c->cpu_shares,
                 prefix, c->startup_cpu_shares,
                 prefix, format_timespan(u, sizeof(u), c->cpu_quota_per_sec_usec, 1),
+                prefix, c->io_weight,
+                prefix, c->startup_io_weight,
                 prefix, c->blockio_weight,
                 prefix, c->startup_blockio_weight,
                 prefix, c->memory_limit,
@@ -139,6 +175,31 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
                         a->path,
                         a->r ? "r" : "", a->w ? "w" : "", a->m ? "m" : "");
 
+        LIST_FOREACH(device_weights, iw, c->io_device_weights)
+                fprintf(f,
+                        "%sIODeviceWeight=%s %" PRIu64,
+                        prefix,
+                        iw->path,
+                        iw->weight);
+
+        LIST_FOREACH(device_limits, il, c->io_device_limits) {
+                char buf[FORMAT_BYTES_MAX];
+
+                if (il->rbps_max != CGROUP_LIMIT_MAX)
+                        fprintf(f,
+                                "%sIOReadBandwidthMax=%s %s\n",
+                                prefix,
+                                il->path,
+                                format_bytes(buf, sizeof(buf), il->rbps_max));
+
+                if (il->wbps_max != CGROUP_LIMIT_MAX)
+                        fprintf(f,
+                                "%sIOWriteBandwidthMax=%s %s\n",
+                                prefix,
+                                il->path,
+                                format_bytes(buf, sizeof(buf), il->wbps_max));
+        }
+
         LIST_FOREACH(device_weights, w, c->blockio_device_weights)
                 fprintf(f,
                         "%sBlockIODeviceWeight=%s %" PRIu64,
@@ -158,7 +219,7 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
         }
 }
 
-static int lookup_blkio_device(const char *p, dev_t *dev) {
+static int lookup_block_device(const char *p, dev_t *dev) {
         struct stat st;
         int r;
 
@@ -343,6 +404,77 @@ void cgroup_context_apply(CGroupContext *c, CGroupMask mask, const char *path, M
                                        "Failed to set cpu.cfs_quota_us on %s: %m", path);
         }
 
+        if (mask & CGROUP_MASK_IO) {
+                CGroupIODeviceWeight *w;
+                CGroupIODeviceLimit *l, *next;
+
+                if (!is_root) {
+                        char buf[MAX(8+DECIMAL_STR_MAX(uint64_t)+1,
+                                     DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1)];
+                        uint64_t weight = CGROUP_WEIGHT_DEFAULT;
+
+                        if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) &&
+                            c->startup_io_weight != CGROUP_WEIGHT_INVALID)
+                                weight = c->startup_io_weight;
+                        else if (c->io_weight != CGROUP_WEIGHT_INVALID)
+                                weight = c->io_weight;
+
+                        xsprintf(buf, "default %" PRIu64 "\n", weight);
+                        r = cg_set_attribute("io", path, "io.weight", buf);
+                        if (r < 0)
+                                log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
+                                               "Failed to set io.weight on %s: %m", path);
+
+                        /* FIXME: no way to reset this list */
+                        LIST_FOREACH(device_weights, w, c->io_device_weights) {
+                                dev_t dev;
+
+                                r = lookup_block_device(w->path, &dev);
+                                if (r < 0)
+                                        continue;
+
+                                xsprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), w->weight);
+                                r = cg_set_attribute("io", path, "io.weight", buf);
+                                if (r < 0)
+                                        log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
+                                                       "Failed to set io.weight on %s: %m", path);
+                        }
+                }
+
+                LIST_FOREACH_SAFE(device_limits, l, next, c->io_device_limits) {
+                        char rbps_buf[DECIMAL_STR_MAX(uint64_t)] = "max";
+                        char wbps_buf[DECIMAL_STR_MAX(uint64_t)] = "max";
+                        char buf[DECIMAL_STR_MAX(dev_t)*2+2+(5+DECIMAL_STR_MAX(uint64_t)+1)*2];
+                        dev_t dev;
+                        unsigned n = 0;
+
+                        r = lookup_block_device(l->path, &dev);
+                        if (r < 0)
+                                continue;
+
+                        if (l->rbps_max != CGROUP_LIMIT_MAX) {
+                                xsprintf(rbps_buf, "%" PRIu64, l->rbps_max);
+                                n++;
+                        }
+
+                        if (l->wbps_max != CGROUP_LIMIT_MAX) {
+                                xsprintf(wbps_buf, "%" PRIu64, l->wbps_max);
+                                n++;
+                        }
+
+                        xsprintf(buf, "%u:%u rbps=%s wbps=%s\n", major(dev), minor(dev), rbps_buf, wbps_buf);
+                        r = cg_set_attribute("io", path, "io.max", buf);
+                        if (r < 0)
+                                log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
+                                               "Failed to set io.max on %s: %m", path);
+
+                        /* If @l contained no config, we just cleared the kernel
+                           counterpart too. No reason to keep @l around. */
+                        if (!n)
+                                cgroup_context_free_io_device_limit(c, l);
+                }
+        }
+
         if (mask & CGROUP_MASK_BLKIO) {
                 char buf[MAX(DECIMAL_STR_MAX(uint64_t)+1,
                              DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1)];
@@ -362,7 +494,7 @@ void cgroup_context_apply(CGroupContext *c, CGroupMask mask, const char *path, M
                         LIST_FOREACH(device_weights, w, c->blockio_device_weights) {
                                 dev_t dev;
 
-                                r = lookup_blkio_device(w->path, &dev);
+                                r = lookup_block_device(w->path, &dev);
                                 if (r < 0)
                                         continue;
 
@@ -379,7 +511,7 @@ void cgroup_context_apply(CGroupContext *c, CGroupMask mask, const char *path, M
                         const char *a;
                         dev_t dev;
 
-                        r = lookup_blkio_device(b->path, &dev);
+                        r = lookup_block_device(b->path, &dev);
                         if (r < 0)
                                 continue;
 
@@ -506,6 +638,13 @@ CGroupMask cgroup_context_get_mask(CGroupContext *c) {
             c->cpu_quota_per_sec_usec != USEC_INFINITY)
                 mask |= CGROUP_MASK_CPUACCT | CGROUP_MASK_CPU;
 
+        if (c->io_accounting ||
+            c->io_weight != CGROUP_WEIGHT_INVALID ||
+            c->startup_io_weight != CGROUP_WEIGHT_INVALID ||
+            c->io_device_weights ||
+            c->io_device_limits)
+                mask |= CGROUP_MASK_IO;
+
         if (c->blockio_accounting ||
             c->blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID ||
             c->startup_blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID ||
@@ -1608,7 +1747,7 @@ void manager_invalidate_startup_units(Manager *m) {
         assert(m);
 
         SET_FOREACH(u, m->startup_units, i)
-                unit_invalidate_cgroup(u, CGROUP_MASK_CPU|CGROUP_MASK_BLKIO);
+                unit_invalidate_cgroup(u, CGROUP_MASK_CPU|CGROUP_MASK_IO|CGROUP_MASK_BLKIO);
 }
 
 static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = {
diff --git a/src/core/cgroup.h b/src/core/cgroup.h
index 360bbca30f..a533923072 100644
--- a/src/core/cgroup.h
+++ b/src/core/cgroup.h
@@ -26,6 +26,8 @@
 
 typedef struct CGroupContext CGroupContext;
 typedef struct CGroupDeviceAllow CGroupDeviceAllow;
+typedef struct CGroupIODeviceWeight CGroupIODeviceWeight;
+typedef struct CGroupIODeviceLimit CGroupIODeviceLimit;
 typedef struct CGroupBlockIODeviceWeight CGroupBlockIODeviceWeight;
 typedef struct CGroupBlockIODeviceBandwidth CGroupBlockIODeviceBandwidth;
 
@@ -53,6 +55,19 @@ struct CGroupDeviceAllow {
         bool m:1;
 };
 
+struct CGroupIODeviceWeight {
+        LIST_FIELDS(CGroupIODeviceWeight, device_weights);
+        char *path;
+        uint64_t weight;
+};
+
+struct CGroupIODeviceLimit {
+        LIST_FIELDS(CGroupIODeviceLimit, device_limits);
+        char *path;
+        uint64_t rbps_max;
+        uint64_t wbps_max;
+};
+
 struct CGroupBlockIODeviceWeight {
         LIST_FIELDS(CGroupBlockIODeviceWeight, device_weights);
         char *path;
@@ -68,10 +83,18 @@ struct CGroupBlockIODeviceBandwidth {
 
 struct CGroupContext {
         bool cpu_accounting;
+        bool io_accounting;
         bool blockio_accounting;
         bool memory_accounting;
         bool tasks_accounting;
 
+        /* For unified hierarchy */
+        uint64_t io_weight;
+        uint64_t startup_io_weight;
+        LIST_HEAD(CGroupIODeviceWeight, io_device_weights);
+        LIST_HEAD(CGroupIODeviceLimit, io_device_limits);
+
+        /* For legacy hierarchies */
         uint64_t cpu_shares;
         uint64_t startup_cpu_shares;
         usec_t cpu_quota_per_sec_usec;
@@ -86,6 +109,7 @@ struct CGroupContext {
         CGroupDevicePolicy device_policy;
         LIST_HEAD(CGroupDeviceAllow, device_allow);
 
+        /* Common */
         uint64_t tasks_max;
 
         bool delegate;
@@ -102,6 +126,8 @@ void cgroup_context_apply(CGroupContext *c, CGroupMask mask, const char *path, M
 CGroupMask cgroup_context_get_mask(CGroupContext *c);
 
 void cgroup_context_free_device_allow(CGroupContext *c, CGroupDeviceAllow *a);
+void cgroup_context_free_io_device_weight(CGroupContext *c, CGroupIODeviceWeight *w);
+void cgroup_context_free_io_device_limit(CGroupContext *c, CGroupIODeviceLimit *l);
 void cgroup_context_free_blockio_device_weight(CGroupContext *c, CGroupBlockIODeviceWeight *w);
 void cgroup_context_free_blockio_device_bandwidth(CGroupContext *c, CGroupBlockIODeviceBandwidth *b);
 
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;
 
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 928b913c7b..ad45611d9d 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -120,6 +120,12 @@ $1.MemoryAccounting,             config_parse_bool,                  0,
 $1.MemoryLimit,                  config_parse_memory_limit,          0,                             offsetof($1, cgroup_context)
 $1.DeviceAllow,                  config_parse_device_allow,          0,                             offsetof($1, cgroup_context)
 $1.DevicePolicy,                 config_parse_device_policy,         0,                             offsetof($1, cgroup_context.device_policy)
+$1.IOAccounting,                 config_parse_bool,                  0,                             offsetof($1, cgroup_context.io_accounting)
+$1.IOWeight,                     config_parse_io_weight,             0,                             offsetof($1, cgroup_context.io_weight)
+$1.StartupIOWeight,              config_parse_io_weight,             0,                             offsetof($1, cgroup_context.startup_io_weight)
+$1.IODeviceWeight,               config_parse_io_device_weight,      0,                             offsetof($1, cgroup_context)
+$1.IOReadBandwidthMax,           config_parse_io_limit,              0,                             offsetof($1, cgroup_context)
+$1.IOWriteBandwidthMax,          config_parse_io_limit,              0,                             offsetof($1, cgroup_context)
 $1.BlockIOAccounting,            config_parse_bool,                  0,                             offsetof($1, cgroup_context.blockio_accounting)
 $1.BlockIOWeight,                config_parse_blockio_weight,        0,                             offsetof($1, cgroup_context.blockio_weight)
 $1.StartupBlockIOWeight,         config_parse_blockio_weight,        0,                             offsetof($1, cgroup_context.startup_blockio_weight)
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 1a8c03904c..9d7329e924 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -2904,6 +2904,196 @@ int config_parse_device_allow(
         return 0;
 }
 
+int config_parse_io_weight(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        uint64_t *weight = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        r = cg_weight_parse(rvalue, weight);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "IO weight '%s' invalid. Ignoring.", rvalue);
+                return 0;
+        }
+
+        return 0;
+}
+
+int config_parse_io_device_weight(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        _cleanup_free_ char *path = NULL;
+        CGroupIODeviceWeight *w;
+        CGroupContext *c = data;
+        const char *weight;
+        uint64_t u;
+        size_t n;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        if (isempty(rvalue)) {
+                while (c->io_device_weights)
+                        cgroup_context_free_io_device_weight(c, c->io_device_weights);
+
+                return 0;
+        }
+
+        n = strcspn(rvalue, WHITESPACE);
+        weight = rvalue + n;
+        weight += strspn(weight, WHITESPACE);
+
+        if (isempty(weight)) {
+                log_syntax(unit, LOG_ERR, filename, line, 0, "Expected block device and device weight. Ignoring.");
+                return 0;
+        }
+
+        path = strndup(rvalue, n);
+        if (!path)
+                return log_oom();
+
+        if (!path_startswith(path, "/dev")) {
+                log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid device node path '%s'. Ignoring.", path);
+                return 0;
+        }
+
+        r = cg_weight_parse(weight, &u);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "IO weight '%s' invalid. Ignoring.", weight);
+                return 0;
+        }
+
+        assert(u != CGROUP_WEIGHT_INVALID);
+
+        w = new0(CGroupIODeviceWeight, 1);
+        if (!w)
+                return log_oom();
+
+        w->path = path;
+        path = NULL;
+
+        w->weight = u;
+
+        LIST_PREPEND(device_weights, c->io_device_weights, w);
+        return 0;
+}
+
+int config_parse_io_limit(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        _cleanup_free_ char *path = NULL;
+        CGroupIODeviceLimit *l = NULL, *t;
+        CGroupContext *c = data;
+        const char *limit;
+        uint64_t num;
+        bool read;
+        size_t n;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        read = streq("IOReadBandwidthMax", lvalue);
+
+        if (isempty(rvalue)) {
+                LIST_FOREACH(device_limits, l, c->io_device_limits)
+                        if (read)
+                                l->rbps_max = CGROUP_LIMIT_MAX;
+                        else
+                                l->wbps_max = CGROUP_LIMIT_MAX;
+                return 0;
+        }
+
+        n = strcspn(rvalue, WHITESPACE);
+        limit = rvalue + n;
+        limit += strspn(limit, WHITESPACE);
+
+        if (!*limit) {
+                log_syntax(unit, LOG_ERR, filename, line, 0, "Expected space separated pair of device node and bandwidth. Ignoring.");
+                return 0;
+        }
+
+        path = strndup(rvalue, n);
+        if (!path)
+                return log_oom();
+
+        if (!path_startswith(path, "/dev")) {
+                log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid device node path '%s'. Ignoring.", path);
+                return 0;
+        }
+
+        if (streq("max", limit)) {
+                num = CGROUP_LIMIT_MAX;
+        } else {
+                r = parse_size(limit, 1000, &num);
+                if (r < 0 || num <= 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "IO Limit '%s' invalid. Ignoring.", rvalue);
+                        return 0;
+                }
+        }
+
+        LIST_FOREACH(device_limits, t, c->io_device_limits) {
+                if (path_equal(path, t->path)) {
+                        l = t;
+                        break;
+                }
+        }
+
+        if (!l) {
+                l = new0(CGroupIODeviceLimit, 1);
+                if (!l)
+                        return log_oom();
+
+                l->path = path;
+                path = NULL;
+                l->rbps_max = CGROUP_LIMIT_MAX;
+                l->wbps_max = CGROUP_LIMIT_MAX;
+
+                LIST_PREPEND(device_limits, c->io_device_limits, l);
+        }
+
+        if (read)
+                l->rbps_max = num;
+        else
+                l->wbps_max = num;
+
+        return 0;
+}
+
 int config_parse_blockio_weight(
                 const char *unit,
                 const char *filename,
@@ -3824,6 +4014,9 @@ void unit_dump_config_items(FILE *f) {
                 { config_parse_memory_limit,          "LIMIT" },
                 { config_parse_device_allow,          "DEVICE" },
                 { config_parse_device_policy,         "POLICY" },
+                { config_parse_io_limit,              "LIMIT" },
+                { config_parse_io_weight,             "WEIGHT" },
+                { config_parse_io_device_weight,      "DEVICEWEIGHT" },
                 { config_parse_blockio_bandwidth,     "BANDWIDTH" },
                 { config_parse_blockio_weight,        "WEIGHT" },
                 { config_parse_blockio_device_weight, "DEVICEWEIGHT" },
diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
index 34f15afa62..b36a2e3a02 100644
--- a/src/core/load-fragment.h
+++ b/src/core/load-fragment.h
@@ -86,6 +86,9 @@ int config_parse_memory_limit(const char *unit, const char *filename, unsigned l
 int config_parse_tasks_max(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_device_policy(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_device_allow(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_io_weight(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_io_device_weight(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_io_limit(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_blockio_weight(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_blockio_device_weight(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_blockio_bandwidth(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
diff --git a/src/core/main.c b/src/core/main.c
index ed4d42c8cc..6397aadc73 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -122,6 +122,7 @@ static usec_t arg_default_timer_accuracy_usec = 1 * USEC_PER_MINUTE;
 static Set* arg_syscall_archs = NULL;
 static FILE* arg_serialization = NULL;
 static bool arg_default_cpu_accounting = false;
+static bool arg_default_io_accounting = false;
 static bool arg_default_blockio_accounting = false;
 static bool arg_default_memory_accounting = false;
 static bool arg_default_tasks_accounting = true;
@@ -691,6 +692,7 @@ static int parse_config_file(void) {
                 { "Manager", "DefaultLimitRTPRIO",        config_parse_limit,            RLIMIT_RTPRIO, arg_default_rlimit         },
                 { "Manager", "DefaultLimitRTTIME",        config_parse_limit,            RLIMIT_RTTIME, arg_default_rlimit         },
                 { "Manager", "DefaultCPUAccounting",      config_parse_bool,             0, &arg_default_cpu_accounting            },
+                { "Manager", "DefaultIOAccounting",       config_parse_bool,             0, &arg_default_io_accounting             },
                 { "Manager", "DefaultBlockIOAccounting",  config_parse_bool,             0, &arg_default_blockio_accounting        },
                 { "Manager", "DefaultMemoryAccounting",   config_parse_bool,             0, &arg_default_memory_accounting         },
                 { "Manager", "DefaultTasksAccounting",    config_parse_bool,             0, &arg_default_tasks_accounting          },
@@ -733,6 +735,7 @@ static void manager_set_defaults(Manager *m) {
         m->default_start_limit_interval = arg_default_start_limit_interval;
         m->default_start_limit_burst = arg_default_start_limit_burst;
         m->default_cpu_accounting = arg_default_cpu_accounting;
+        m->default_io_accounting = arg_default_io_accounting;
         m->default_blockio_accounting = arg_default_blockio_accounting;
         m->default_memory_accounting = arg_default_memory_accounting;
         m->default_tasks_accounting = arg_default_tasks_accounting;
diff --git a/src/core/manager.h b/src/core/manager.h
index 17f84e6963..f23e4056c4 100644
--- a/src/core/manager.h
+++ b/src/core/manager.h
@@ -252,6 +252,7 @@ struct Manager {
 
         bool default_cpu_accounting;
         bool default_memory_accounting;
+        bool default_io_accounting;
         bool default_blockio_accounting;
         bool default_tasks_accounting;
 
diff --git a/src/core/system.conf b/src/core/system.conf
index eacd7ee282..db8b7acd78 100644
--- a/src/core/system.conf
+++ b/src/core/system.conf
@@ -38,6 +38,7 @@
 #DefaultStartLimitBurst=5
 #DefaultEnvironment=
 #DefaultCPUAccounting=no
+#DefaultIOAccounting=no
 #DefaultBlockIOAccounting=no
 #DefaultMemoryAccounting=no
 #DefaultTasksAccounting=yes
diff --git a/src/core/unit.c b/src/core/unit.c
index 8153515e89..04addc1f70 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -132,6 +132,7 @@ static void unit_init(Unit *u) {
                  * been initialized */
 
                 cc->cpu_accounting = u->manager->default_cpu_accounting;
+                cc->io_accounting = u->manager->default_io_accounting;
                 cc->blockio_accounting = u->manager->default_blockio_accounting;
                 cc->memory_accounting = u->manager->default_memory_accounting;
                 cc->tasks_accounting = u->manager->default_tasks_accounting;
@@ -1213,6 +1214,7 @@ static int unit_add_startup_units(Unit *u) {
                 return 0;
 
         if (c->startup_cpu_shares == CGROUP_CPU_SHARES_INVALID &&
+            c->startup_io_weight == CGROUP_WEIGHT_INVALID &&
             c->startup_blockio_weight == CGROUP_BLKIO_WEIGHT_INVALID)
                 return 0;