core: add support for IOReadIOPSMax and IOWriteIOPSMax

cgroup IO controller supports maximum limits for both bandwidth and IOPS but
systemd resource control currently only supports bandwidth limits.  This patch
adds support for IOReadIOPSMax and IOWriteIOPSMax when unified cgroup hierarchy
is in use.

It isn't difficult to also add BlockIOReadIOPS and BlockIOWriteIOPS for legacy
hierarchies but IO control on legacy hierarchies is half-broken anyway, so
let's leave it alone for now.

5 files changed, 14 insertions, 3 deletions

diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index 8eab100748..7cdc97ee3c 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -2272,11 +2272,15 @@ int cg_weight_parse(const char *s, uint64_t *ret) {
 const uint64_t cgroup_io_limit_defaults[_CGROUP_IO_LIMIT_TYPE_MAX] = {
         [CGROUP_IO_RBPS_MAX]    = CGROUP_LIMIT_MAX,
         [CGROUP_IO_WBPS_MAX]    = CGROUP_LIMIT_MAX,
+        [CGROUP_IO_RIOPS_MAX]   = CGROUP_LIMIT_MAX,
+        [CGROUP_IO_WIOPS_MAX]   = CGROUP_LIMIT_MAX,
 };
 
 static const char* const cgroup_io_limit_type_table[_CGROUP_IO_LIMIT_TYPE_MAX] = {
         [CGROUP_IO_RBPS_MAX]    = "IOReadBandwidthMax",
         [CGROUP_IO_WBPS_MAX]    = "IOWriteBandwidthMax",
+        [CGROUP_IO_RIOPS_MAX]   = "IOReadIOPSMax",
+        [CGROUP_IO_WIOPS_MAX]   = "IOWriteIOPSMax",
 };
 
 DEFINE_STRING_TABLE_LOOKUP(cgroup_io_limit_type, CGroupIOLimitType);
diff --git a/src/basic/cgroup-util.h b/src/basic/cgroup-util.h
index 0d96fb6b76..4bb5291296 100644
--- a/src/basic/cgroup-util.h
+++ b/src/basic/cgroup-util.h
@@ -76,6 +76,8 @@ static inline bool CGROUP_WEIGHT_IS_OK(uint64_t x) {
 typedef enum CGroupIOLimitType {
         CGROUP_IO_RBPS_MAX,
         CGROUP_IO_WBPS_MAX,
+        CGROUP_IO_RIOPS_MAX,
+        CGROUP_IO_WIOPS_MAX,
 
         _CGROUP_IO_LIMIT_TYPE_MAX,
         _CGROUP_IO_LIMIT_TYPE_INVALID = -1
diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 0b902fa6f7..a54634469f 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -439,7 +439,7 @@ void cgroup_context_apply(CGroupContext *c, CGroupMask mask, const char *path, M
 
                 LIST_FOREACH_SAFE(device_limits, l, next, c->io_device_limits) {
                         char limit_bufs[_CGROUP_IO_LIMIT_TYPE_MAX][DECIMAL_STR_MAX(uint64_t)];
-                        char buf[DECIMAL_STR_MAX(dev_t)*2+2+(5+DECIMAL_STR_MAX(uint64_t)+1)*2];
+                        char buf[DECIMAL_STR_MAX(dev_t)*2+2+(6+DECIMAL_STR_MAX(uint64_t)+1)*4];
                         CGroupIOLimitType type;
                         dev_t dev;
                         unsigned n = 0;
@@ -458,8 +458,9 @@ void cgroup_context_apply(CGroupContext *c, CGroupMask mask, const char *path, M
                                 }
                         }
 
-                        xsprintf(buf, "%u:%u rbps=%s wbps=%s\n", major(dev), minor(dev),
-                                 limit_bufs[CGROUP_IO_RBPS_MAX], limit_bufs[CGROUP_IO_WBPS_MAX]);
+                        xsprintf(buf, "%u:%u rbps=%s wbps=%s riops=%s wiops=%s\n", major(dev), minor(dev),
+                                 limit_bufs[CGROUP_IO_RBPS_MAX], limit_bufs[CGROUP_IO_WBPS_MAX],
+                                 limit_bufs[CGROUP_IO_RIOPS_MAX], limit_bufs[CGROUP_IO_WIOPS_MAX]);
                         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,
diff --git a/src/core/dbus-cgroup.c b/src/core/dbus-cgroup.c
index 4372828e30..29c2edaf6b 100644
--- a/src/core/dbus-cgroup.c
+++ b/src/core/dbus-cgroup.c
@@ -213,6 +213,8 @@ const sd_bus_vtable bus_cgroup_vtable[] = {
         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("IOReadIOPSMax", "a(st)", property_get_io_device_limits, 0, 0),
+        SD_BUS_PROPERTY("IOWriteIOPSMax", "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),
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index ad45611d9d..8193418980 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -126,6 +126,8 @@ $1.StartupIOWeight,              config_parse_io_weight,             0,
 $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.IOReadIOPSMax,                config_parse_io_limit,              0,                             offsetof($1, cgroup_context)
+$1.IOWriteIOPSMax,               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)