ipld-eth-server/vendor/github.com/ipfs/go-ipfs/fuse/mount/fuse.go

163 lines
3.2 KiB
Go

// +build !nofuse
// +build !windows
package mount
import (
"errors"
"fmt"
"sync"
"time"
"bazil.org/fuse"
"bazil.org/fuse/fs"
"github.com/jbenet/goprocess"
)
var ErrNotMounted = errors.New("not mounted")
// mount implements go-ipfs/fuse/mount
type mount struct {
mpoint string
filesys fs.FS
fuseConn *fuse.Conn
active bool
activeLock *sync.RWMutex
proc goprocess.Process
}
// Mount mounts a fuse fs.FS at a given location, and returns a Mount instance.
// parent is a ContextGroup to bind the mount's ContextGroup to.
func NewMount(p goprocess.Process, fsys fs.FS, mountpoint string, allow_other bool) (Mount, error) {
var conn *fuse.Conn
var err error
if allow_other {
conn, err = fuse.Mount(mountpoint, fuse.AllowOther())
} else {
conn, err = fuse.Mount(mountpoint)
}
if err != nil {
return nil, err
}
m := &mount{
mpoint: mountpoint,
fuseConn: conn,
filesys: fsys,
active: false,
activeLock: &sync.RWMutex{},
proc: goprocess.WithParent(p), // link it to parent.
}
m.proc.SetTeardown(m.unmount)
// launch the mounting process.
if err := m.mount(); err != nil {
_ = m.Unmount() // just in case.
return nil, err
}
return m, nil
}
func (m *mount) mount() error {
log.Infof("Mounting %s", m.MountPoint())
errs := make(chan error, 1)
go func() {
// fs.Serve blocks until the filesystem is unmounted.
err := fs.Serve(m.fuseConn, m.filesys)
log.Debugf("%s is unmounted", m.MountPoint())
if err != nil {
log.Debugf("fs.Serve returned (%s)", err)
errs <- err
}
m.setActive(false)
}()
// wait for the mount process to be done, or timed out.
select {
case <-time.After(MountTimeout):
return fmt.Errorf("mounting %s timed out", m.MountPoint())
case err := <-errs:
return err
case <-m.fuseConn.Ready:
}
// check if the mount process has an error to report
if err := m.fuseConn.MountError; err != nil {
return err
}
m.setActive(true)
log.Infof("Mounted %s", m.MountPoint())
return nil
}
// umount is called exactly once to unmount this service.
// note that closing the connection will not always unmount
// properly. If that happens, we bring out the big guns
// (mount.ForceUnmountManyTimes, exec unmount).
func (m *mount) unmount() error {
log.Infof("Unmounting %s", m.MountPoint())
// try unmounting with fuse lib
err := fuse.Unmount(m.MountPoint())
if err == nil {
m.setActive(false)
return nil
}
log.Warningf("fuse unmount err: %s", err)
// try closing the fuseConn
err = m.fuseConn.Close()
if err == nil {
m.setActive(false)
return nil
}
log.Warningf("fuse conn error: %s", err)
// try mount.ForceUnmountManyTimes
if err := ForceUnmountManyTimes(m, 10); err != nil {
return err
}
log.Infof("Seemingly unmounted %s", m.MountPoint())
m.setActive(false)
return nil
}
func (m *mount) Process() goprocess.Process {
return m.proc
}
func (m *mount) MountPoint() string {
return m.mpoint
}
func (m *mount) Unmount() error {
if !m.IsActive() {
return ErrNotMounted
}
// call Process Close(), which calls unmount() exactly once.
return m.proc.Close()
}
func (m *mount) IsActive() bool {
m.activeLock.RLock()
defer m.activeLock.RUnlock()
return m.active
}
func (m *mount) setActive(a bool) {
m.activeLock.Lock()
m.active = a
m.activeLock.Unlock()
}