swarm/api: support mounting manifests via FUSE (#3690)

5 files changed, 623 insertions, 0 deletions

diff --git a/swarm/api/fuse.go b/swarm/api/fuse.go
new file mode 100644
index 000000000..4b1f817f8
--- /dev/null
+++ b/swarm/api/fuse.go
@@ -0,0 +1,139 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build !windows
+
+package api
+
+import (
+	"io"
+	"os"
+
+	"bazil.org/fuse"
+	"bazil.org/fuse/fs"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/swarm/storage"
+	"golang.org/x/net/context"
+)
+
+
+
+
+// Data structures used for Fuse filesystem, serving directories and serving files to Fuse driver
+type FS struct {
+	root *Dir
+}
+
+type Dir struct {
+	inode       uint64
+	name        string
+	path        string
+	directories []*Dir
+	files       []*File
+}
+
+type File struct {
+	inode    uint64
+	name     string
+	path     string
+	key      storage.Key
+	swarmApi *Api
+	fileSize uint64
+	reader   storage.LazySectionReader
+}
+
+
+// Functions which satisfy the Fuse File System requests
+func (filesystem *FS) Root() (fs.Node, error) {
+	return filesystem.root, nil
+}
+
+func (directory *Dir) Attr(ctx context.Context, a *fuse.Attr) error {
+	a.Inode = directory.inode
+	//TODO: need to get permission as argument
+	a.Mode = os.ModeDir | 0500
+	a.Uid = uint32(os.Getuid())
+	a.Gid = uint32(os.Getegid())
+	return nil
+}
+
+func (directory *Dir) Lookup(ctx context.Context, name string) (fs.Node, error) {
+	if directory.files != nil {
+		for _, n := range directory.files {
+			if n.name == name {
+				return n, nil
+			}
+		}
+	}
+	if directory.directories != nil {
+		for _, n := range directory.directories {
+			if n.name == name {
+				return n, nil
+			}
+		}
+	}
+	return nil, fuse.ENOENT
+}
+
+func (d *Dir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
+	var children []fuse.Dirent
+	if d.files != nil {
+		for _, file := range d.files {
+			children = append(children, fuse.Dirent{Inode: file.inode, Type: fuse.DT_File, Name: file.name})
+		}
+	}
+	if d.directories != nil {
+		for _, dir := range d.directories {
+			children = append(children, fuse.Dirent{Inode: dir.inode, Type: fuse.DT_Dir, Name: dir.name})
+		}
+	}
+	return children, nil
+}
+
+func (file *File) Attr(ctx context.Context, a *fuse.Attr) error {
+
+	a.Inode = file.inode
+	//TODO: need to get permission as argument
+	a.Mode = 0500
+	a.Uid = uint32(os.Getuid())
+	a.Gid = uint32(os.Getegid())
+
+
+	reader := file.swarmApi.Retrieve(file.key)
+	quitC := make(chan bool)
+	size, err := reader.Size(quitC)
+	if err != nil {
+		log.Warn("Couldnt file size of file %s : %v", file.path, err)
+		a.Size = uint64(0)
+	}
+	a.Size = uint64(size)
+	file.fileSize = a.Size
+	return nil
+}
+
+var _ = fs.HandleReader(&File{})
+
+func (file *File) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error {
+	buf := make([]byte, req.Size)
+	reader := file.swarmApi.Retrieve(file.key)
+	n, err := reader.ReadAt(buf, req.Offset)
+	if err == io.ErrUnexpectedEOF || err == io.EOF {
+		err = nil
+	}
+	resp.Data = buf[:n]
+	return err
+
+}
diff --git a/swarm/api/swarmfs.go b/swarm/api/swarmfs.go
new file mode 100644
index 000000000..8427d3c5b
--- /dev/null
+++ b/swarm/api/swarmfs.go
@@ -0,0 +1,48 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package api
+
+import (
+	"time"
+	"sync"
+)
+
+const (
+	Swarmfs_Version = "0.1"
+	mountTimeout   = time.Second * 5
+	maxFuseMounts  = 5
+)
+
+
+type SwarmFS struct {
+	swarmApi     *Api
+	activeMounts map[string]*MountInfo
+	activeLock   *sync.RWMutex
+}
+
+
+
+func NewSwarmFS(api *Api) *SwarmFS {
+	swarmfs := &SwarmFS{
+		swarmApi:     api,
+		activeLock:   &sync.RWMutex{},
+		activeMounts: map[string]*MountInfo{},
+	}
+	return swarmfs
+}
+
+
diff --git a/swarm/api/swarmfs_unix.go b/swarm/api/swarmfs_unix.go
new file mode 100644
index 000000000..ae0216e1d
--- /dev/null
+++ b/swarm/api/swarmfs_unix.go
@@ -0,0 +1,266 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build linux darwin
+
+package api
+
+import (
+	"path/filepath"
+	"fmt"
+	"strings"
+	"time"
+	"github.com/ethereum/go-ethereum/swarm/storage"
+	"bazil.org/fuse"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/common"
+	"bazil.org/fuse/fs"
+	"sync"
+)
+
+
+var (
+	inode  uint64  = 1
+	inodeLock   sync.RWMutex
+)
+
+// information about every active mount
+type MountInfo struct {
+	mountPoint     string
+	manifestHash   string
+	resolvedKey    storage.Key
+	rootDir        *Dir
+	fuseConnection *fuse.Conn
+}
+
+// Inode numbers need to be unique, they are used for caching inside fuse
+func NewInode() uint64 {
+	inodeLock.Lock()
+	defer  inodeLock.Unlock()
+	inode += 1
+	return inode
+}
+
+
+
+func (self *SwarmFS) Mount(mhash, mountpoint string) (string, error)  {
+
+	self.activeLock.Lock()
+	defer self.activeLock.Unlock()
+
+	noOfActiveMounts := len(self.activeMounts)
+	if noOfActiveMounts >= maxFuseMounts {
+		err := fmt.Errorf("Max mount count reached. Cannot mount %s ", mountpoint)
+		log.Warn(err.Error())
+		return err.Error(), err
+	}
+
+	cleanedMountPoint, err := filepath.Abs(filepath.Clean(mountpoint))
+	if err != nil {
+		return err.Error(), err
+	}
+
+	if _, ok := self.activeMounts[cleanedMountPoint]; ok {
+		err := fmt.Errorf("Mountpoint %s already mounted.", cleanedMountPoint)
+		log.Warn(err.Error())
+		return err.Error(), err
+	}
+
+	log.Info(fmt.Sprintf("Attempting to mount %s ", cleanedMountPoint))
+	key, _, path, err := self.swarmApi.parseAndResolve(mhash, true)
+	if err != nil {
+		errStr := fmt.Sprintf("Could not resolve %s : %v", mhash, err)
+		log.Warn(errStr)
+		return errStr, err
+	}
+
+	if len(path) > 0 {
+		path += "/"
+	}
+
+	quitC := make(chan bool)
+	trie, err := loadManifest(self.swarmApi.dpa, key, quitC)
+	if err != nil {
+		errStr := fmt.Sprintf("fs.Download: loadManifestTrie error: %v", err)
+		log.Warn(errStr)
+		return errStr, err
+	}
+
+	dirTree := map[string]*Dir{}
+
+	rootDir := &Dir{
+		inode:       NewInode(),
+		name:        "root",
+		directories: nil,
+		files:       nil,
+	}
+	dirTree["root"] = rootDir
+
+	err = trie.listWithPrefix(path, quitC, func(entry *manifestTrieEntry, suffix string) {
+
+		key = common.Hex2Bytes(entry.Hash)
+		fullpath := "/" + suffix
+		basepath := filepath.Dir(fullpath)
+		filename := filepath.Base(fullpath)
+
+		parentDir := rootDir
+		dirUntilNow := ""
+		paths := strings.Split(basepath, "/")
+		for i := range paths {
+			if paths[i] != "" {
+				thisDir := paths[i]
+				dirUntilNow = dirUntilNow + "/" + thisDir
+
+				if _, ok := dirTree[dirUntilNow]; !ok {
+					dirTree[dirUntilNow] = &Dir{
+						inode:       NewInode(),
+						name:        thisDir,
+						path:        dirUntilNow,
+						directories: nil,
+						files:       nil,
+					}
+					parentDir.directories = append(parentDir.directories, dirTree[dirUntilNow])
+					parentDir = dirTree[dirUntilNow]
+
+				} else {
+					parentDir = dirTree[dirUntilNow]
+				}
+
+			}
+		}
+		thisFile := &File{
+			inode:    NewInode(),
+			name:     filename,
+			path:     fullpath,
+			key:      key,
+			swarmApi: self.swarmApi,
+		}
+		parentDir.files = append(parentDir.files, thisFile)
+	})
+
+	fconn, err := fuse.Mount(cleanedMountPoint, fuse.FSName("swarmfs"), fuse.VolumeName(mhash))
+	if err != nil {
+		fuse.Unmount(cleanedMountPoint)
+		errStr := fmt.Sprintf("Mounting %s encountered error: %v", cleanedMountPoint, err)
+		log.Warn(errStr)
+		return errStr, err
+	}
+
+	mounterr := make(chan error, 1)
+	go func() {
+		log.Info(fmt.Sprintf("Serving %s at %s", mhash, cleanedMountPoint))
+		filesys := &FS{root: rootDir}
+		if err := fs.Serve(fconn, filesys); err != nil {
+			log.Warn(fmt.Sprintf("Could not Serve FS error: %v", err))
+		}
+	}()
+
+	// Check if the mount process has an error to report.
+	select {
+
+	case <-time.After(mountTimeout):
+		err := fmt.Errorf("Mounting %s timed out.", cleanedMountPoint)
+		log.Warn(err.Error())
+		return err.Error(), err
+
+	case err := <-mounterr:
+	        errStr := fmt.Sprintf("Mounting %s encountered error: %v", cleanedMountPoint, err)
+		log.Warn(errStr)
+		return errStr, err
+
+	case <-fconn.Ready:
+		log.Debug(fmt.Sprintf("Mounting connection succeeded for : %v", cleanedMountPoint))
+	}
+
+
+
+	//Assemble and Store the mount information for future use
+	mountInformation := &MountInfo{
+		mountPoint:     cleanedMountPoint,
+		manifestHash:   mhash,
+		resolvedKey:    key,
+		rootDir:        rootDir,
+		fuseConnection: fconn,
+	}
+	self.activeMounts[cleanedMountPoint] = mountInformation
+
+	succString := fmt.Sprintf("Mounting successful for %s", cleanedMountPoint)
+	log.Info(succString)
+
+	return succString, nil
+}
+
+func (self *SwarmFS) Unmount(mountpoint string) (string, error)  {
+
+	self.activeLock.Lock()
+	defer self.activeLock.Unlock()
+
+	cleanedMountPoint, err := filepath.Abs(filepath.Clean(mountpoint))
+	if err != nil {
+		return err.Error(), err
+	}
+
+	// Get the mount information based on the mountpoint argument
+	mountInfo := self.activeMounts[cleanedMountPoint]
+
+
+	if mountInfo == nil || mountInfo.mountPoint != cleanedMountPoint {
+		err := fmt.Errorf("Could not find mount information for %s ", cleanedMountPoint)
+		log.Warn(err.Error())
+		return err.Error(), err
+	}
+
+	err = fuse.Unmount(cleanedMountPoint)
+	if err != nil {
+		//TODO: try forceful unmount if normal unmount fails
+		errStr := fmt.Sprintf("UnMount error: %v", err)
+		log.Warn(errStr)
+		return errStr, err
+	}
+
+	mountInfo.fuseConnection.Close()
+
+	//remove the mount information from the active map
+	delete(self.activeMounts, cleanedMountPoint)
+
+	succString := fmt.Sprintf("UnMounting %v succeeded", cleanedMountPoint)
+	log.Info(succString)
+	return succString, nil
+}
+
+func (self *SwarmFS) Listmounts() (string, error) {
+
+	self.activeLock.RLock()
+	defer self.activeLock.RUnlock()
+
+	var rows []string
+	for mp := range self.activeMounts {
+		mountInfo := self.activeMounts[mp]
+		rows = append(rows, fmt.Sprintf("Swarm Root: %s, Mount Point: %s ", mountInfo.manifestHash, mountInfo.mountPoint))
+	}
+
+	return strings.Join(rows, "\n"), nil
+}
+
+func (self *SwarmFS) Stop() bool {
+
+	for mp := range self.activeMounts {
+		mountInfo := self.activeMounts[mp]
+		self.Unmount(mountInfo.mountPoint)
+	}
+
+	return true
+}
diff --git a/swarm/api/swarmfs_unix_test.go b/swarm/api/swarmfs_unix_test.go
new file mode 100644
index 000000000..4f59dba5b
--- /dev/null
+++ b/swarm/api/swarmfs_unix_test.go
@@ -0,0 +1,122 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build linux darwin
+
+package api
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+var testUploadDir, _ = ioutil.TempDir(os.TempDir(), "fuse-source")
+var testMountDir, _ = ioutil.TempDir(os.TempDir(), "fuse-dest")
+
+func testFuseFileSystem(t *testing.T, f func(*FileSystem)) {
+	testApi(t, func(api *Api) {
+		f(NewFileSystem(api))
+	})
+}
+
+func createTestFiles(t *testing.T, files []string) {
+
+	os.RemoveAll(testUploadDir)
+	os.RemoveAll(testMountDir)
+	defer os.MkdirAll(testMountDir, 0777)
+
+	for f := range files {
+		actualPath := filepath.Join(testUploadDir, files[f])
+		filePath := filepath.Dir(actualPath)
+
+		err := os.MkdirAll(filePath, 0777)
+		if err != nil {
+			t.Fatalf("Error creating directory '%v' : %v", filePath, err)
+		}
+
+		_, err1 := os.OpenFile(actualPath, os.O_RDONLY|os.O_CREATE, 0666)
+		if err1 != nil {
+			t.Fatalf("Error creating file %v: %v", actualPath, err1)
+		}
+	}
+
+}
+
+func compareFiles(t *testing.T, files []string) {
+
+	for f := range files {
+
+		sourceFile := filepath.Join(testUploadDir, files[f])
+		destinationFile := filepath.Join(testMountDir, files[f])
+
+		sfinfo, err := os.Stat(sourceFile)
+		if err != nil {
+			t.Fatalf("Source file %v missing in mount: %v", files[f], err)
+		}
+
+		dfinfo, err := os.Stat(destinationFile)
+		if err != nil {
+			t.Fatalf("Destination file %v missing in mount: %v", files[f], err)
+		}
+
+		if sfinfo.Size() != dfinfo.Size() {
+			t.Fatalf("Size mismatch  source (%v) vs destination(%v)", sfinfo.Size(), dfinfo.Size())
+		}
+
+		if dfinfo.Mode().Perm().String() != "-r-x------" {
+			t.Fatalf("Permission is not 0500for file: %v", err)
+		}
+
+	}
+}
+
+func doHashTest(fs *FileSystem, t *testing.T, ensName string, files ...string) {
+
+	createTestFiles(t, files)
+	bzzhash, err := fs.Upload(testUploadDir, "")
+	if err != nil {
+		t.Fatalf("Error uploading directory %v: %v", testUploadDir, err)
+	}
+
+	swarmfs := NewSwarmFS(fs.api)
+	_ ,err1 := swarmfs.Mount(bzzhash, testMountDir)
+	if err1 != nil {
+
+		t.Fatalf("Error mounting hash  %v: %v", bzzhash, err)
+	}
+	compareFiles(t, files)
+	_, err2 := swarmfs.Unmount(testMountDir)
+	if err2 != nil {
+		t.Fatalf("Error unmounting path  %v: %v", testMountDir, err)
+	}
+	swarmfs.Stop()
+
+}
+
+// mounting with manifest Hash
+func TestFuseMountingScenarios(t *testing.T) {
+	testFuseFileSystem(t, func(fs *FileSystem) {
+
+		//doHashTest(fs,t, "test","1.txt")
+		doHashTest(fs, t, "", "1.txt")
+		doHashTest(fs, t, "", "1.txt", "11.txt", "111.txt", "two/2.txt", "two/two/2.txt", "three/3.txt")
+		doHashTest(fs, t, "", "1/2/3/4/5/6/7/8/9/10/11/12/1.txt")
+		doHashTest(fs, t, "", "one/one.txt", "one.txt", "once/one.txt", "one/one/one.txt")
+
+	})
+}
diff --git a/swarm/api/swarmfs_windows.go b/swarm/api/swarmfs_windows.go
new file mode 100644
index 000000000..525a25399
--- /dev/null
+++ b/swarm/api/swarmfs_windows.go
@@ -0,0 +1,48 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build windows
+
+package api
+
+import (
+	"github.com/ethereum/go-ethereum/log"
+)
+
+// Dummy struct and functions to satsfy windows build
+type MountInfo struct {
+}
+
+
+func (self *SwarmFS) Mount(mhash, mountpoint string) error {
+	log.Info("Platform not supported")
+	return nil
+}
+
+func (self *SwarmFS) Unmount(mountpoint string) error {
+	log.Info("Platform not supported")
+	return nil
+}
+
+func (self *SwarmFS) Listmounts() (string, error) {
+	log.Info("Platform not supported")
+	return "",nil
+}
+
+func (self *SwarmFS) Stop() error {
+	log.Info("Platform not supported")
+	return nil
+}
\ No newline at end of file