Add linux scsi disk detection and attribute mapping

pkgs/scsi/.gitignore

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+scsi

pkgs/scsi/constants.go

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+/*
+ * 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
+
+var (
+	// From 2.6.x kernel onwards, no need to support procfs
+	SYSFSROOT                = "/sys"
+	SYSFS_SCSI_DEVICES       = "/sys/bus/scsi/devices/"
+	SYSFS_BLOCK              = "/block/"
+	SYSFS_CLASS_SCSI_DEVICES = "/sys/class/scsi_device/"
+	UDEV                     = "/dev/"
+	DEV_DISK_BYID_DIR        = "/dev/disk/by-id"
+)
+
+var SCSI_DEVICE_TYPES = []string{
+	"disk",
+	"tape",
+	"printer",
+	"process",
+	"worm",
+	"cd/dvd",
+	"scanner",
+	"optical",
+	"mediumx",
+	"comms",
+	"(0xa)",
+	"(0xb)",
+	"storage",
+	"enclosu",
+	"sim disk",
+	"optical rd",
+	"bridge",
+	"osd",
+	"adi",
+	"sec man",
+	"zbc",
+	"(0x15)",
+	"(0x16)",
+	"(0x17)",
+	"(0x18)",
+	"(0x19)",
+	"(0x1a)",
+	"(0x1b)",
+	"(0x1c)",
+	"(0x1e)",
+	"wlun",
+	"no dev",
+}

pkgs/scsi/scsi.go

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+/*
+ * 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
+}

pkgs/scsi/scsi_test.go

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+// !build linux,amd64
+package scsi
+
+import (
+	. "gopkg.in/check.v1"
+	"testing"
+)
+
+type MySuite struct{}
+
+var _ = Suite(&MySuite{})
+
+func Test(t *testing.T) { TestingT(t) }
+
+func (s *MySuite) TestSCSI(c *C) {
+	var d Devices
+	err := d.Get()
+	c.Assert(err, IsNil)
+	c.Assert(len(d.List), Equals, 1)
+}

pkgs/scsi/utils.go

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+/*
+ * 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 (
+	"io/ioutil"
+	"os"
+	"path"
+	"strings"
+)
+
+func getattrs(scsiAttrPath string, scsiAttrList []string) map[string][]byte {
+	attrMap := make(map[string][]byte)
+	for _, attr := range scsiAttrList {
+		value, _ := ioutil.ReadFile(path.Join(scsiAttrPath, attr))
+		attrMap[attr] = value
+	}
+	return attrMap
+}
+
+func filterdevices(files []os.FileInfo) (scsidevices []string) {
+	for _, fi := range files {
+		if strings.Contains(fi.Name(), "host") {
+			continue
+		}
+		if strings.Contains(fi.Name(), "target") {
+			continue
+		}
+		scsidevices = append(scsidevices, fi.Name())
+	}
+	return scsidevices
+}