// Rollback rolls back the volume to the given snapshot
func (c *BtrfsConn) Rollback(label string) error {
if exists, err := c.snapshotExists(label); err != nil || !exists {
if err != nil {
return err
} else {
return fmt.Errorf("snapshot %s does not exist", label)
}
}
c.Lock()
defer c.Unlock()
vd := path.Join(c.root, c.name)
dirp, err := volume.IsDir(vd)
if err != nil {
return err
}
glog.Infof("starting rollback of snapshot %s", label)
start := time.Now()
if dirp {
timeout := getEnvMinDuration("SERVICED_BTRFS_ROLLBACK_TIMEOUT", 300, 120)
glog.Infof("rollback using env var SERVICED_BTRFS_ROLLBACK_TIMEOUT:%s", timeout)
for {
cmd := []string{"subvolume", "delete", vd}
output, deleteError := runcmd(c.sudoer, cmd...)
if deleteError == nil {
break
}
now := time.Now()
if now.Sub(start) > timeout {
glog.Errorf("rollback of snapshot %s failed - btrfs subvolume deletes took %s for cmd:%s", label, timeout, cmd)
return deleteError
} else if strings.Contains(string(output), "Device or resource busy") {
waitTime := time.Duration(5 * time.Second)
glog.Warningf("retrying rollback subvolume delete in %s - unable to run cmd:%s output:%s error:%s", waitTime, cmd, string(output), deleteError)
time.Sleep(waitTime)
} else {
return deleteError
}
}
}
cmd := []string{"subvolume", "snapshot", c.SnapshotPath(label), vd}
_, err = runcmd(c.sudoer, cmd...)
if err != nil {
glog.Errorf("rollback of snapshot %s failed for cmd:%s", label, cmd)
} else {
duration := time.Now().Sub(start)
glog.Infof("rollback of snapshot %s took %s", label, duration)
}
return err
}
// Snapshot performs a writable snapshot on the subvolume
func (c *RsyncConn) Snapshot(label string) (err error) {
c.Lock()
defer c.Unlock()
dest := c.SnapshotPath(label)
if exists, err := volume.IsDir(dest); exists || err != nil {
if exists {
return fmt.Errorf("snapshot %s already exists", label)
}
return err
}
exe, err := exec.LookPath("rsync")
if err != nil {
return err
}
argv := []string{"-a", c.Path() + "/", dest + "/"}
glog.Infof("Performing snapshot rsync command: %s %s", exe, argv)
var output []byte
for i := 0; i < 3; i++ {
rsync := exec.Command(exe, argv...)
done := make(chan interface{})
go func() {
defer close(done)
output, err = rsync.CombinedOutput()
}()
select {
case <-time.After(c.timeout):
glog.V(2).Infof("Received signal to kill rsync")
rsync.Process.Kill()
<-done
case <-done:
}
if err == nil {
return nil
}
if exitStatus, ok := utils.GetExitStatus(err); !ok || exitStatus != 24 {
glog.Errorf("Could not perform rsync: %s", string(output))
return err
}
glog.Infof("trying snapshot again: %s", label)
}
if exitStatus, _ := utils.GetExitStatus(err); exitStatus == 24 {
glog.Warningf("snapshot completed with errors: Partial transfer due to vanished source files")
return nil
}
glog.Errorf("Could not perform rsync: %s", string(output))
return err
}
// Import imports a snapshot
func (c *RsyncConn) Import(label, indir string) (err error) {
c.Lock()
defer c.Unlock()
if exists, err := volume.IsDir(c.SnapshotPath(label)); err != nil {
return err
} else if exists {
return fmt.Errorf("snapshot %s exists", label)
}
rsync := exec.Command("rsync", "-azh", filepath.Join(indir, label), c.root)
glog.V(4).Infof("About ro execute %s", rsync)
if output, err := rsync.CombinedOutput(); err != nil {
glog.V(2).Infof("Could not perform rsync: %s", string(output))
return err
}
return nil
}
// Export copys a snapshot
func (c *RsyncConn) Export(label, parent, outdir string) (err error) {
c.Lock()
defer c.Unlock()
src := c.SnapshotPath(label)
if exists, err := volume.IsDir(src); err != nil {
return err
} else if !exists {
return fmt.Errorf("snapshot %s does not exist", label)
}
rsync := exec.Command("rsync", "-azh", src, outdir)
glog.V(4).Infof("About ro execute %s", rsync)
if output, err := rsync.CombinedOutput(); err != nil {
glog.V(2).Infof("Could not perform rsync: %s", string(output))
return err
}
return nil
}
// Rollback rolls back the volume to the given snapshot
func (c *RsyncConn) Rollback(label string) (err error) {
c.Lock()
defer c.Unlock()
src := c.SnapshotPath(label)
if exists, err := volume.IsDir(src); !exists || err != nil {
if !exists {
return fmt.Errorf("snapshot %s does not exist", label)
}
return err
}
rsync := exec.Command("rsync", "-a", "--del", "--force", src+"/", c.Path()+"/")
glog.V(4).Infof("About to execute: %s", rsync)
if output, err := rsync.CombinedOutput(); err != nil {
glog.V(2).Infof("Could not perform rsync: %s", string(output))
return err
}
return nil
}
