diff --git a/devicemapper/devmapper.go b/devicemapper/devmapper.go index dc3185e..db3244a 100644 --- a/devicemapper/devmapper.go +++ b/devicemapper/devmapper.go @@ -47,32 +47,29 @@ const ( // List of errors returned when using devicemapper. var ( - ErrTaskRun = errors.New("dm_task_run failed") - ErrTaskSetName = errors.New("dm_task_set_name failed") - ErrTaskSetMessage = errors.New("dm_task_set_message failed") - ErrTaskSetAddNode = errors.New("dm_task_set_add_node failed") - ErrTaskSetRo = errors.New("dm_task_set_ro failed") - ErrTaskAddTarget = errors.New("dm_task_add_target failed") - ErrTaskSetSector = errors.New("dm_task_set_sector failed") - ErrTaskGetDeps = errors.New("dm_task_get_deps failed") - ErrTaskGetInfo = errors.New("dm_task_get_info failed") - ErrTaskGetDriverVersion = errors.New("dm_task_get_driver_version failed") - ErrTaskDeferredRemove = errors.New("dm_task_deferred_remove failed") - ErrTaskSetCookie = errors.New("dm_task_set_cookie failed") - ErrNilCookie = errors.New("cookie ptr can't be nil") - ErrAttachLoopbackDevice = errors.New("loopback mounting failed") - ErrGetBlockSize = errors.New("Can't get block size") - ErrUdevWait = errors.New("wait on udev cookie failed") - ErrSetDevDir = errors.New("dm_set_dev_dir failed") - ErrGetLibraryVersion = errors.New("dm_get_library_version failed") - ErrCreateRemoveTask = errors.New("Can't create task of type deviceRemove") - ErrRunRemoveDevice = errors.New("running RemoveDevice failed") - ErrInvalidAddNode = errors.New("Invalid AddNode type") - ErrGetLoopbackBackingFile = errors.New("Unable to get loopback backing file") - ErrLoopbackSetCapacity = errors.New("Unable set loopback capacity") - ErrBusy = errors.New("Device is Busy") - ErrDeviceIDExists = errors.New("Device Id Exists") - ErrEnxio = errors.New("No such device or address") + ErrTaskRun = errors.New("dm_task_run failed") + ErrTaskSetName = errors.New("dm_task_set_name failed") + ErrTaskSetMessage = errors.New("dm_task_set_message failed") + ErrTaskSetAddNode = errors.New("dm_task_set_add_node failed") + ErrTaskSetRo = errors.New("dm_task_set_ro failed") + ErrTaskAddTarget = errors.New("dm_task_add_target failed") + ErrTaskSetSector = errors.New("dm_task_set_sector failed") + ErrTaskGetDeps = errors.New("dm_task_get_deps failed") + ErrTaskGetInfo = errors.New("dm_task_get_info failed") + ErrTaskGetDriverVersion = errors.New("dm_task_get_driver_version failed") + ErrTaskDeferredRemove = errors.New("dm_task_deferred_remove failed") + ErrTaskSetCookie = errors.New("dm_task_set_cookie failed") + ErrNilCookie = errors.New("cookie ptr can't be nil") + ErrGetBlockSize = errors.New("Can't get block size") + ErrUdevWait = errors.New("wait on udev cookie failed") + ErrSetDevDir = errors.New("dm_set_dev_dir failed") + ErrGetLibraryVersion = errors.New("dm_get_library_version failed") + ErrCreateRemoveTask = errors.New("Can't create task of type deviceRemove") + ErrRunRemoveDevice = errors.New("running RemoveDevice failed") + ErrInvalidAddNode = errors.New("Invalid AddNode type") + ErrBusy = errors.New("Device is Busy") + ErrDeviceIDExists = errors.New("Device Id Exists") + ErrEnxio = errors.New("No such device or address") ) var ( @@ -257,58 +254,6 @@ func (t *Task) getNextTarget(next unsafe.Pointer) (nextPtr unsafe.Pointer, start start, length, targetType, params } -func getLoopbackBackingFile(file *os.File) (uint64, uint64, error) { - loopInfo, err := ioctlLoopGetStatus64(file.Fd()) - if err != nil { - logrus.Errorf("devicemapper: Error get loopback backing file: %s", err) - return 0, 0, ErrGetLoopbackBackingFile - } - return loopInfo.loDevice, loopInfo.loInode, nil -} - -// LoopbackSetCapacity reloads the size for the loopback device. -func LoopbackSetCapacity(file *os.File) error { - if err := ioctlLoopSetCapacity(file.Fd(), 0); err != nil { - logrus.Errorf("devicemapper: Error loopbackSetCapacity: %s", err) - return ErrLoopbackSetCapacity - } - return nil -} - -// FindLoopDeviceFor returns a loopback device file for the specified file which -// is backing file of a loop back device. -func FindLoopDeviceFor(file *os.File) *os.File { - stat, err := file.Stat() - if err != nil { - return nil - } - targetInode := stat.Sys().(*syscall.Stat_t).Ino - targetDevice := stat.Sys().(*syscall.Stat_t).Dev - - for i := 0; true; i++ { - path := fmt.Sprintf("/dev/loop%d", i) - - file, err := os.OpenFile(path, os.O_RDWR, 0) - if err != nil { - if os.IsNotExist(err) { - return nil - } - - // Ignore all errors until the first not-exist - // we want to continue looking for the file - continue - } - - dev, inode, err := getLoopbackBackingFile(file) - if err == nil && dev == targetDevice && inode == targetInode { - return file - } - file.Close() - } - - return nil -} - // UdevWait waits for any processes that are waiting for udev to complete the specified cookie. func UdevWait(cookie *uint) error { if res := DmUdevWait(*cookie); res != 1 { diff --git a/devicemapper/devmapper_wrapper.go b/devicemapper/devmapper_wrapper.go index a99c329..91fbc85 100644 --- a/devicemapper/devmapper_wrapper.go +++ b/devicemapper/devmapper_wrapper.go @@ -5,17 +5,8 @@ package devicemapper /* #cgo LDFLAGS: -L. -ldevmapper #include -#include // FIXME: present only for defines, maybe we can remove it? #include // FIXME: present only for BLKGETSIZE64, maybe we can remove it? -#ifndef LOOP_CTL_GET_FREE - #define LOOP_CTL_GET_FREE 0x4C82 -#endif - -#ifndef LO_FLAGS_PARTSCAN - #define LO_FLAGS_PARTSCAN 8 -#endif - // FIXME: Can't we find a way to do the logging in pure Go? extern void DevmapperLogCallback(int level, char *file, int line, int dm_errno_or_class, char *str); @@ -45,45 +36,12 @@ import ( type ( cdmTask C.struct_dm_task - - cLoopInfo64 C.struct_loop_info64 - loopInfo64 struct { - loDevice uint64 /* ioctl r/o */ - loInode uint64 /* ioctl r/o */ - loRdevice uint64 /* ioctl r/o */ - loOffset uint64 - loSizelimit uint64 /* bytes, 0 == max available */ - loNumber uint32 /* ioctl r/o */ - loEncryptType uint32 - loEncryptKeySize uint32 /* ioctl w/o */ - loFlags uint32 /* ioctl r/o */ - loFileName [LoNameSize]uint8 - loCryptName [LoNameSize]uint8 - loEncryptKey [LoKeySize]uint8 /* ioctl w/o */ - loInit [2]uint64 - } ) // IOCTL consts const ( BlkGetSize64 = C.BLKGETSIZE64 BlkDiscard = C.BLKDISCARD - - LoopSetFd = C.LOOP_SET_FD - LoopCtlGetFree = C.LOOP_CTL_GET_FREE - LoopGetStatus64 = C.LOOP_GET_STATUS64 - LoopSetStatus64 = C.LOOP_SET_STATUS64 - LoopClrFd = C.LOOP_CLR_FD - LoopSetCapacity = C.LOOP_SET_CAPACITY -) - -// LOOP consts. -const ( - LoFlagsAutoClear = C.LO_FLAGS_AUTOCLEAR - LoFlagsReadOnly = C.LO_FLAGS_READ_ONLY - LoFlagsPartScan = C.LO_FLAGS_PARTSCAN - LoKeySize = C.LO_KEY_SIZE - LoNameSize = C.LO_NAME_SIZE ) // Devicemapper cookie flags. diff --git a/devicemapper/ioctl.go b/devicemapper/ioctl.go index 1ccc16c..581b57e 100644 --- a/devicemapper/ioctl.go +++ b/devicemapper/ioctl.go @@ -7,51 +7,6 @@ import ( "unsafe" ) -func ioctlLoopCtlGetFree(fd uintptr) (int, error) { - index, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, LoopCtlGetFree, 0) - if err != 0 { - return 0, err - } - return int(index), nil -} - -func ioctlLoopSetFd(loopFd, sparseFd uintptr) error { - if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopSetFd, sparseFd); err != 0 { - return err - } - return nil -} - -func ioctlLoopSetStatus64(loopFd uintptr, loopInfo *loopInfo64) error { - if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopSetStatus64, uintptr(unsafe.Pointer(loopInfo))); err != 0 { - return err - } - return nil -} - -func ioctlLoopClrFd(loopFd uintptr) error { - if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopClrFd, 0); err != 0 { - return err - } - return nil -} - -func ioctlLoopGetStatus64(loopFd uintptr) (*loopInfo64, error) { - loopInfo := &loopInfo64{} - - if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopGetStatus64, uintptr(unsafe.Pointer(loopInfo))); err != 0 { - return nil, err - } - return loopInfo, nil -} - -func ioctlLoopSetCapacity(loopFd uintptr, value int) error { - if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopSetCapacity, uintptr(value)); err != 0 { - return err - } - return nil -} - func ioctlBlkGetSize64(fd uintptr) (int64, error) { var size int64 if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, BlkGetSize64, uintptr(unsafe.Pointer(&size))); err != 0 { diff --git a/devicemapper/attach_loopback.go b/loopback/attach_loopback.go similarity index 92% rename from devicemapper/attach_loopback.go rename to loopback/attach_loopback.go index 30e0a48..c6d72d7 100644 --- a/devicemapper/attach_loopback.go +++ b/loopback/attach_loopback.go @@ -1,8 +1,9 @@ // +build linux -package devicemapper +package loopback import ( + "errors" "fmt" "os" "syscall" @@ -10,6 +11,13 @@ import ( "github.com/Sirupsen/logrus" ) +// Loopback related errors +var ( + ErrAttachLoopbackDevice = errors.New("loopback attach failed") + ErrGetLoopbackBackingFile = errors.New("Unable to get loopback backing file") + ErrSetCapacity = errors.New("Unable set loopback capacity") +) + func stringToLoopName(src string) [LoNameSize]uint8 { var dst [LoNameSize]uint8 copy(dst[:], src[:]) diff --git a/loopback/ioctl.go b/loopback/ioctl.go new file mode 100644 index 0000000..0714eb5 --- /dev/null +++ b/loopback/ioctl.go @@ -0,0 +1,53 @@ +// +build linux + +package loopback + +import ( + "syscall" + "unsafe" +) + +func ioctlLoopCtlGetFree(fd uintptr) (int, error) { + index, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, LoopCtlGetFree, 0) + if err != 0 { + return 0, err + } + return int(index), nil +} + +func ioctlLoopSetFd(loopFd, sparseFd uintptr) error { + if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopSetFd, sparseFd); err != 0 { + return err + } + return nil +} + +func ioctlLoopSetStatus64(loopFd uintptr, loopInfo *loopInfo64) error { + if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopSetStatus64, uintptr(unsafe.Pointer(loopInfo))); err != 0 { + return err + } + return nil +} + +func ioctlLoopClrFd(loopFd uintptr) error { + if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopClrFd, 0); err != 0 { + return err + } + return nil +} + +func ioctlLoopGetStatus64(loopFd uintptr) (*loopInfo64, error) { + loopInfo := &loopInfo64{} + + if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopGetStatus64, uintptr(unsafe.Pointer(loopInfo))); err != 0 { + return nil, err + } + return loopInfo, nil +} + +func ioctlLoopSetCapacity(loopFd uintptr, value int) error { + if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopSetCapacity, uintptr(value)); err != 0 { + return err + } + return nil +} diff --git a/loopback/loop_wrapper.go b/loopback/loop_wrapper.go new file mode 100644 index 0000000..e1100ce --- /dev/null +++ b/loopback/loop_wrapper.go @@ -0,0 +1,52 @@ +// +build linux + +package loopback + +/* +#include // FIXME: present only for defines, maybe we can remove it? + +#ifndef LOOP_CTL_GET_FREE + #define LOOP_CTL_GET_FREE 0x4C82 +#endif + +#ifndef LO_FLAGS_PARTSCAN + #define LO_FLAGS_PARTSCAN 8 +#endif + +*/ +import "C" + +type loopInfo64 struct { + loDevice uint64 /* ioctl r/o */ + loInode uint64 /* ioctl r/o */ + loRdevice uint64 /* ioctl r/o */ + loOffset uint64 + loSizelimit uint64 /* bytes, 0 == max available */ + loNumber uint32 /* ioctl r/o */ + loEncryptType uint32 + loEncryptKeySize uint32 /* ioctl w/o */ + loFlags uint32 /* ioctl r/o */ + loFileName [LoNameSize]uint8 + loCryptName [LoNameSize]uint8 + loEncryptKey [LoKeySize]uint8 /* ioctl w/o */ + loInit [2]uint64 +} + +// IOCTL consts +const ( + LoopSetFd = C.LOOP_SET_FD + LoopCtlGetFree = C.LOOP_CTL_GET_FREE + LoopGetStatus64 = C.LOOP_GET_STATUS64 + LoopSetStatus64 = C.LOOP_SET_STATUS64 + LoopClrFd = C.LOOP_CLR_FD + LoopSetCapacity = C.LOOP_SET_CAPACITY +) + +// LOOP consts. +const ( + LoFlagsAutoClear = C.LO_FLAGS_AUTOCLEAR + LoFlagsReadOnly = C.LO_FLAGS_READ_ONLY + LoFlagsPartScan = C.LO_FLAGS_PARTSCAN + LoKeySize = C.LO_KEY_SIZE + LoNameSize = C.LO_NAME_SIZE +) diff --git a/loopback/loopback.go b/loopback/loopback.go new file mode 100644 index 0000000..bc04792 --- /dev/null +++ b/loopback/loopback.go @@ -0,0 +1,63 @@ +// +build linux + +package loopback + +import ( + "fmt" + "os" + "syscall" + + "github.com/Sirupsen/logrus" +) + +func getLoopbackBackingFile(file *os.File) (uint64, uint64, error) { + loopInfo, err := ioctlLoopGetStatus64(file.Fd()) + if err != nil { + logrus.Errorf("Error get loopback backing file: %s", err) + return 0, 0, ErrGetLoopbackBackingFile + } + return loopInfo.loDevice, loopInfo.loInode, nil +} + +// SetCapacity reloads the size for the loopback device. +func SetCapacity(file *os.File) error { + if err := ioctlLoopSetCapacity(file.Fd(), 0); err != nil { + logrus.Errorf("Error loopbackSetCapacity: %s", err) + return ErrSetCapacity + } + return nil +} + +// FindLoopDeviceFor returns a loopback device file for the specified file which +// is backing file of a loop back device. +func FindLoopDeviceFor(file *os.File) *os.File { + stat, err := file.Stat() + if err != nil { + return nil + } + targetInode := stat.Sys().(*syscall.Stat_t).Ino + targetDevice := stat.Sys().(*syscall.Stat_t).Dev + + for i := 0; true; i++ { + path := fmt.Sprintf("/dev/loop%d", i) + + file, err := os.OpenFile(path, os.O_RDWR, 0) + if err != nil { + if os.IsNotExist(err) { + return nil + } + + // Ignore all errors until the first not-exist + // we want to continue looking for the file + continue + } + + dev, inode, err := getLoopbackBackingFile(file) + if err == nil && dev == targetDevice && inode == targetInode { + return file + } + file.Close() + } + + return nil +}