add ruleguard support, fix all the reported issues (#10335)

pkg/sys/stats_linux.go

@@ -1,4 +1,4 @@
-// +build linux
+// +build linux,!arm,!386
 
 /*
  * MinIO Cloud Storage, (C) 2016,2017 MinIO, Inc.
@@ -64,13 +64,12 @@ func getSysinfoMemoryLimit() (limit uint64, err error) {
 
 	// Some fields in syscall.Sysinfo_t have different  integer sizes
 	// in different platform architectures. Cast all fields to uint64.
-	totalRAM := uint64(si.Totalram)
-	unit := uint64(si.Unit)
+	unit := si.Unit
+	totalRAM := si.Totalram
 
 	// Total RAM is always the multiplicative value
 	// of unit size and total ram.
-	limit = unit * totalRAM
-	return limit, nil
+	return uint64(unit) * totalRAM, nil
 }
 
 // GetStats - return system statistics, currently only

pkg/sys/stats_linux_32bit.go

@@ -0,0 +1,86 @@
+// +build linux,arm linux,386
+
+/*
+ * MinIO Cloud Storage, (C) 2020 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package sys
+
+import (
+	"os"
+	"syscall"
+
+	"github.com/minio/minio/pkg/cgroup"
+)
+
+// Get the final system memory limit chosen by the user.
+// by default without any configuration on a vanilla Linux
+// system you would see physical RAM limit. If cgroup
+// is configured at some point in time this function
+// would return the memory limit chosen for the given pid.
+func getMemoryLimit() (sysLimit uint64, err error) {
+	if sysLimit, err = getSysinfoMemoryLimit(); err != nil {
+		// Physical memory info is not accessible, just exit here.
+		return 0, err
+	}
+
+	// Following code is deliberately ignoring the error.
+	cGroupLimit, gerr := cgroup.GetMemoryLimit(os.Getpid())
+	if gerr != nil {
+		// Upon error just return system limit.
+		return sysLimit, nil
+	}
+
+	// cgroup limit is lesser than system limit means
+	// user wants to limit the memory usage further
+	// treat cgroup limit as the system limit.
+	if cGroupLimit <= sysLimit {
+		sysLimit = cGroupLimit
+	}
+
+	// Final system limit.
+	return sysLimit, nil
+
+}
+
+// Get physical RAM size of the node.
+func getSysinfoMemoryLimit() (limit uint64, err error) {
+	var si syscall.Sysinfo_t
+	if err = syscall.Sysinfo(&si); err != nil {
+		return 0, err
+	}
+
+	// Some fields in syscall.Sysinfo_t have different  integer sizes
+	// in different platform architectures. Cast all fields to uint64.
+	unit := si.Unit
+	totalRAM := si.Totalram
+
+	// Total RAM is always the multiplicative value
+	// of unit size and total ram.
+	return uint64(unit) * uint64(totalRAM), nil
+}
+
+// GetStats - return system statistics, currently only
+// supported value is TotalRAM.
+func GetStats() (stats Stats, err error) {
+	var limit uint64
+	limit, err = getMemoryLimit()
+	if err != nil {
+		return Stats{}, err
+	}
+
+	stats.TotalRAM = limit
+	return stats, nil
+}