add NVMe drive info [model num, serial num, drive temp. etc.] (#10613)

* add NVMe drive info [model num, serial num, drive temp. etc.]
* Ignore fuse partitions
* Add the nvme logic only for linux
* Move smart/nvme structs to a separate file

Co-authored-by: wlan0 <sidharthamn@gmail.com>

pkg/smart/nvme.go

@@ -0,0 +1,89 @@
+// +build linux
+
+/*
+ * MinIO Cloud Storage, (C) 2016-2020 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.
+ */
+
+/*
+ * This file has been adopted and then modified from Daniel Swarbrick's smart
+ * project residing at https://github.com/dswarbrick/smart
+ *
+ */
+
+package smart
+
+import (
+	"fmt"
+	"math/big"
+	"unsafe"
+
+	"github.com/dswarbrick/smart/ioctl"
+	"golang.org/x/sys/unix"
+)
+
+// NVMe admin disk query constants
+const (
+	NvmeAdminGetLogPage = 0x02
+	NvmeAdminIdentify   = 0x06
+)
+
+var (
+	nvmeIoctlAdminCmd = ioctl.Iowr('N', 0x41, unsafe.Sizeof(nvmePassthruCommand{}))
+)
+
+// NewNVMeDevice creates a new NVMeDevice struct with name
+func NewNVMeDevice(name string) *NVMeDevice {
+	return &NVMeDevice{name, -1}
+}
+
+// Open - open device file to find kernel info
+func (d *NVMeDevice) Open() (err error) {
+	d.fd, err = unix.Open(d.Name, unix.O_RDWR, 0600)
+	return err
+}
+
+// Close - closes device file
+func (d *NVMeDevice) Close() error {
+	return unix.Close(d.fd)
+}
+
+func (d *NVMeDevice) readLogPage(logID uint8, buf *[]byte) error {
+	bufLen := len(*buf)
+
+	if (bufLen < 4) || (bufLen > 0x4000) || (bufLen%4 != 0) {
+		return fmt.Errorf("Invalid buffer size")
+	}
+
+	cmd := nvmePassthruCommand{
+		opcode:  NvmeAdminGetLogPage,
+		nsid:    0xffffffff, // FIXME
+		addr:    uint64(uintptr(unsafe.Pointer(&(*buf)[0]))),
+		dataLen: uint32(bufLen),
+		cdw10:   uint32(logID) | (((uint32(bufLen) / 4) - 1) << 16),
+	}
+
+	return ioctl.Ioctl(uintptr(d.fd), nvmeIoctlAdminCmd, uintptr(unsafe.Pointer(&cmd)))
+}
+
+// le128ToBigInt takes a little-endian 16-byte slice and returns a *big.Int representing it.
+func le128ToBigInt(buf [16]byte) *big.Int {
+	// Int.SetBytes() expects big-endian input, so reverse the bytes locally first
+	rev := make([]byte, 16)
+	for x := 0; x < 16; x++ {
+		rev[x] = buf[16-x-1]
+	}
+
+	return new(big.Int).SetBytes(rev)
+}