// 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 freebsd
package api
import (
"errors"
"fmt"
"os"
"path/filepath"
"strings"
"sync"
"time"
"bazil.org/fuse"
"bazil.org/fuse/fs"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/swarm/storage"
)
var (
inode uint64 = 1
inodeLock sync.RWMutex
)
var (
errEmptyMountPoint = errors.New("need non-empty mount point")
errMaxMountCount = errors.New("max FUSE mount count reached")
errMountTimeout = errors.New("mount timeout")
)
func isFUSEUnsupportedError(err error) bool {
if perr, ok := err.(*os.PathError); ok {
return perr.Op == "open" && perr.Path == "/dev/fuse"
}
return err == fuse.ErrOSXFUSENotFound
}
// MountInfo contains information about every active mount
type MountInfo struct {
MountPoint string
ManifestHash string
resolvedKey storage.Key
rootDir *Dir
fuseConnection *fuse.Conn
}
// newInode creates a new inode number.
// 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) (*MountInfo, error) {
if mountpoint == "" {
return nil, errEmptyMountPoint
}
cleanedMountPoint, err := filepath.Abs(filepath.Clean(mountpoint))
if err != nil {
return nil, err
}
self.activeLock.Lock()
defer self.activeLock.Unlock()
noOfActiveMounts := len(self.activeMounts)
if noOfActiveMounts >= maxFuseMounts {
return nil, errMaxMountCount
}
if _, ok := self.activeMounts[cleanedMountPoint]; ok {
return nil, fmt.Errorf("%s is already mounted", cleanedMountPoint)
}
key, _, path, err := self.swarmApi.parseAndResolve(mhash, true)
if err != nil {
return nil, fmt.Errorf("can't resolve %q: %v", mhash, err)
}
if len(path) > 0 {
path += "/"
}
quitC := make(chan bool)
trie, err := loadManifest(self.swarmApi.dpa, key, quitC)
if err != nil {
return nil, fmt.Errorf("can't load manifest %v: %v", key.String(), 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)
log.Warn("Error mounting swarm manifest", "mountpoint", cleanedMountPoint, "err", err)
return nil, err
}
mounterr := make(chan error, 1)
go func() {
filesys := &FS{root: rootDir}
if err := fs.Serve(fconn, filesys); err != nil {
mounterr <- err
}
}()
// Check if the mount process has an error to report.
select {
case <-time.After(mountTimeout):
fuse.Unmount(cleanedMountPoint)
return nil, errMountTimeout
case err := <-mounterr:
log.Warn("Error serving swarm FUSE FS", "mountpoint", cleanedMountPoint, "err", err)
return nil, err
case <-fconn.Ready:
log.Info("Now serving swarm FUSE FS", "manifest", mhash, "mountpoint", cleanedMountPoint)
}
// Assemble and Store the mount information for future use
mi := &MountInfo{
MountPoint: cleanedMountPoint,
ManifestHash: mhash,
resolvedKey: key,
rootDir: rootDir,
fuseConnection: fconn,
}
self.activeMounts[cleanedMountPoint] = mi
return mi, nil
}
func (self *SwarmFS) Unmount(mountpoint string) (bool, error) {
self.activeLock.Lock()
defer self.activeLock.Unlock()
cleanedMountPoint, err := filepath.Abs(filepath.Clean(mountpoint))
if err != nil {
return false, err
}
mountInfo := self.activeMounts[cleanedMountPoint]
if mountInfo == nil || mountInfo.MountPoint != cleanedMountPoint {
return false, fmt.Errorf("%s is not mounted", cleanedMountPoint)
}
err = fuse.Unmount(cleanedMountPoint)
if err != nil {
// TODO(jmozah): try forceful unmount if normal unmount fails
return false, err
}
// remove the mount information from the active map
mountInfo.fuseConnection.Close()
delete(self.activeMounts, cleanedMountPoint)
return true, nil
}
func (self *SwarmFS) Listmounts() []*MountInfo {
self.activeLock.RLock()
defer self.activeLock.RUnlock()
rows := make([]*MountInfo, 0, len(self.activeMounts))
for _, mi := range self.activeMounts {
rows = append(rows, mi)
}
return rows
}
func (self *SwarmFS) Stop() bool {
for mp := range self.activeMounts {
mountInfo := self.activeMounts[mp]
self.Unmount(mountInfo.MountPoint)
}
return true
}
