Graph Driver-device Mapper-04libdevmapper Basic operations

Create thin pool//call path: newdeviceset->initdevmapper->createpool1.1 func createpool (poolname string, datafile, Metadatafile *os. File, poolblocksize UInt32) error {//The interaction task is encapsulated with Libdevmapper through a task, err: = CreateTask (Devicecreate, poolname) if task = = Ni L {return Err}//data block device size, via ioctlsize, err: = Getblockdevicesize (datafile) if err! = Nil {return FMT. Errorf ("Can ' t get data size%s", err)}//create thin pool parameter params: = FMT. Sprintf ("%s%s%d 32768 1 skip_block_zeroing", Metadatafile.name (), Datafile.name (), poolblocksize)//Add function parameter If err: = Task . AddTarget (0, size/512, "Thin-pool", params); Err! = Nil {return FMT. Errorf ("Can ' t add target%s", err)}//Create a sync amount var cookie uint = 0if ERR: = task. Setcookie (&cookie, 0); Err! = Nil {return FMT. Errorf ("Can ' t set cookie%s", err)}//perform the task if err: = task. Run (); Err! = Nil {return FMT. Errorf ("Error running Devicecreate (createpool)%s", err)}//wait for thin pool to be created udevwait (cookie) return nil}//create operation, The task encapsulates the operation of the Devicemapper 1.2 func createtask (t TaskType, name String (*task, error) {//create TaskType corresponding wrapper function Task: = taskcreate (t) if Task = = Nil {return nil, fmt. Errorf ("Can ' t create task of type%d", int (t))}if ERR: = task. SetName (name); Err! = Nil {return nil, fmt. Errorf ("Can ' t set task Name%s", name)}return task, nil}//creates a specified action type 1.3 func taskcreate (TaskType tasktype) *task {//create operation C Task: = dmtaskcreate (int (tasktype)) if Ctask = = Nil {return Nil}task: = &task{unmanaged:ctask}runtime. Setfinalizer (Task, (*task). Destroy) return task}//create the specified operation//dmtaskcreate=dmtaskcreatefct1.4 func dmtaskcreatefct ( TaskType int) *cdmtask {return (*cdmtask) (C.dm_task_create (C.int (TaskType)))}