X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/8690785168e12635ce35614c02d557fe77a3fe25..13288c69988380210150124d7991af6ca6e3d62b:/services/keepstore/volume.go?ds=sidebyside

diff --git a/services/keepstore/volume.go b/services/keepstore/volume.go
index 7e001a2470..69802abdd1 100644
--- a/services/keepstore/volume.go
+++ b/services/keepstore/volume.go
@@ -1,8 +1,13 @@
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
 package main
 
 import (
 	"context"
 	"crypto/rand"
+	"fmt"
 	"io"
 	"math/big"
 	"sync/atomic"
@@ -231,6 +236,10 @@ type Volume interface {
 	// EmptyTrash looks for trashed blocks that exceeded TrashLifetime
 	// and deletes them from the volume.
 	EmptyTrash()
+
+	// Return a globally unique ID of the underlying storage
+	// device if possible, otherwise "".
+	DeviceID() string
 }
 
 // A VolumeWithExamples provides example configs to display in the
@@ -246,6 +255,11 @@ type VolumeManager interface {
 	// Mounts returns all mounts (volume attachments).
 	Mounts() []*VolumeMount
 
+	// Lookup returns the volume under the given mount
+	// UUID. Returns nil if the mount does not exist. If
+	// write==true, returns nil if the volume is not writable.
+	Lookup(uuid string, write bool) Volume
+
 	// AllReadable returns all volumes.
 	AllReadable() []Volume
 
@@ -270,11 +284,12 @@ type VolumeManager interface {
 
 // A VolumeMount is an attachment of a Volume to a VolumeManager.
 type VolumeMount struct {
-	UUID     string
-	DeviceID string
-	ReadOnly bool
-	Tier     int
-	volume   Volume
+	UUID        string
+	DeviceID    string
+	ReadOnly    bool
+	Replication int
+	Tier        int
+	volume      Volume
 }
 
 // Generate a UUID the way API server would for a "KeepVolumeMount"
@@ -289,7 +304,7 @@ func (*VolumeMount) generateUUID() string {
 	if err != nil {
 		panic(err)
 	}
-	return "zzzzz-ivpuk-" + r.Text(36)
+	return fmt.Sprintf("zzzzz-ivpuk-%015s", r.Text(36))
 }
 
 // RRVolumeManager is a round-robin VolumeManager: the Nth call to
@@ -297,6 +312,7 @@ func (*VolumeMount) generateUUID() string {
 // (where writables are all Volumes v where v.Writable()==true).
 type RRVolumeManager struct {
 	mounts    []*VolumeMount
+	mountMap  map[string]*VolumeMount
 	readables []Volume
 	writables []Volume
 	counter   uint32
@@ -308,21 +324,19 @@ func MakeRRVolumeManager(volumes []Volume) *RRVolumeManager {
 	vm := &RRVolumeManager{
 		iostats: make(map[Volume]*ioStats),
 	}
+	vm.mountMap = make(map[string]*VolumeMount)
 	for _, v := range volumes {
 		mnt := &VolumeMount{
-			UUID:     (*VolumeMount)(nil).generateUUID(),
-			DeviceID: "",
-			ReadOnly: !v.Writable(),
-			Tier:     1,
-			volume:   v,
-		}
-		if v, ok := v.(interface {
-			DeviceID() string
-		}); ok {
-			mnt.DeviceID = v.DeviceID()
+			UUID:        (*VolumeMount)(nil).generateUUID(),
+			DeviceID:    v.DeviceID(),
+			ReadOnly:    !v.Writable(),
+			Replication: v.Replication(),
+			Tier:        1,
+			volume:      v,
 		}
 		vm.iostats[v] = &ioStats{}
 		vm.mounts = append(vm.mounts, mnt)
+		vm.mountMap[mnt.UUID] = mnt
 		vm.readables = append(vm.readables, v)
 		if v.Writable() {
 			vm.writables = append(vm.writables, v)
@@ -335,6 +349,14 @@ func (vm *RRVolumeManager) Mounts() []*VolumeMount {
 	return vm.mounts
 }
 
+func (vm *RRVolumeManager) Lookup(uuid string, needWrite bool) Volume {
+	if mnt, ok := vm.mountMap[uuid]; ok && (!needWrite || !mnt.ReadOnly) {
+		return mnt.volume
+	} else {
+		return nil
+	}
+}
+
 // AllReadable returns an array of all readable volumes
 func (vm *RRVolumeManager) AllReadable() []Volume {
 	return vm.readables