Add linux scsi disk detection and attribute mapping

pkgs/scsi/scsi.go

@@ -0,0 +1,96 @@
+/*
+ * Mini Object Storage, (C) 2014 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.
+ */
+
+// !build linux,amd64
+
+package scsi
+
+import (
+	"errors"
+	"io/ioutil"
+	"path"
+)
+
+// NOTE : supporting virtio based scsi devices
+//        is out of scope for this implementation
+
+type _Scsi struct {
+	device  string
+	attrMap map[string][]byte
+}
+
+type Devices struct {
+	List []_Scsi
+}
+
+func (d *Devices) Get() error {
+	var scsidevices []string
+	var scsiAttrList []string
+
+	sysfs := path.Join(SYSFS_SCSI_DEVICES)
+	sysFiles, err := ioutil.ReadDir(sysfs)
+	if err != nil {
+		return err
+	}
+
+	scsidevices = filterdevices(sysFiles)
+	if len(scsidevices) == 0 {
+		return errors.New("No scsi devices found on the system")
+	}
+
+	for _, scsi := range scsidevices {
+		var _scsi _Scsi
+		scsiAttrPath := path.Join(sysfs, scsi, "/")
+		scsiAttrs, err := ioutil.ReadDir(scsiAttrPath)
+		if err != nil {
+			return err
+		}
+		scsiBlockPath := path.Join(sysfs, scsi, SYSFS_BLOCK)
+		scsidevList, err := ioutil.ReadDir(scsiBlockPath)
+		if err != nil {
+			return err
+		}
+
+		if len(scsidevList) > 1 {
+			return errors.New("Scsi address points to multiple block devices")
+		}
+
+		_scsi.device = UDEV + scsidevList[0].Name()
+		for _, sa := range scsiAttrs {
+			// Skip directories
+			if sa.IsDir() {
+				continue
+			}
+			// Skip symlinks
+			if !sa.Mode().IsRegular() {
+				continue
+			}
+			// Skip, not readable, write-only
+			if sa.Mode().Perm() == 128 {
+				continue
+			}
+			scsiAttrList = append(scsiAttrList, sa.Name())
+		}
+
+		if len(scsiAttrList) == 0 {
+			return errors.New("No scsi attributes found")
+		}
+		attrMap := getattrs(scsiAttrPath, scsiAttrList)
+		_scsi.attrMap = attrMap
+		d.List = append(d.List, _scsi)
+	}
+	return nil
+}