add scoutfs move_blocks

c_defs_linux.go

@@ -62,6 +62,7 @@ package scoutfs
 // };
 //
 // typedef struct scoutfs_ioctl_alloc_detail_entry_mod scoutfs_ioctl_alloc_detail_entry_t;
+// typedef struct scoutfs_ioctl_move_blocks scoutfs_ioctl_move_blocks_t;
 import "C"
 
 const IOCQUERYINODES = C.SCOUTFS_IOC_WALK_INODES
@@ -76,6 +77,7 @@ const IOCSEARCHXATTRS = C.SCOUTFS_IOC_SEARCH_XATTRS
 const IOCSTATFSMORE = C.SCOUTFS_IOC_STATFS_MORE
 const IOCDATAWAITERR = C.SCOUTFS_IOC_DATA_WAIT_ERR
 const IOCALLOCDETAIL = C.SCOUTFS_IOC_ALLOC_DETAIL
+const IOCMOVEBLOCKS = C.SCOUTFS_IOC_MOVE_BLOCKS
 
 const QUERYINODESMETASEQ = C.SCOUTFS_IOC_WALK_INODES_META_SEQ
 const QUERYINODESDATASEQ = C.SCOUTFS_IOC_WALK_INODES_DATA_SEQ
@@ -101,5 +103,6 @@ type searchXattrs C.scoutfs_ioctl_search_xattrs_t
 type statfsMore C.scoutfs_ioctl_statfs_more_t
 type allocDetail C.scoutfs_ioctl_alloc_detail_t
 type allocDetailEntry C.scoutfs_ioctl_alloc_detail_entry_t
+type moveBlocks C.scoutfs_ioctl_move_blocks_t
 
 const sizeofstatfsMore = C.sizeof_scoutfs_ioctl_statfs_more_t

examples/moveblocks/main.go

@@ -0,0 +1,41 @@
+// Copyright (c) 2021 Versity Software, Inc.
+//
+// Use of this source code is governed by a BSD-3-Clause license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package main
+
+import (
+	"fmt"
+	"os"
+
+	scoutfs "github.com/versity/scoutfs-go"
+)
+
+func main() {
+	if len(os.Args) != 3 || os.Args[1] == "-h" {
+		fmt.Fprintln(os.Stderr, "usage:", os.Args[0], "<file_to_move_blocks_from> <file_to_append_blocks_to>")
+		os.Exit(1)
+	}
+
+	ffrom, err := os.OpenFile(os.Args[1], os.O_RDWR, 0666)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "open %v: %v\n", os.Args[1], err)
+		os.Exit(1)
+	}
+	defer ffrom.Close()
+
+	fto, err := os.OpenFile(os.Args[2], os.O_RDWR, 0666)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "open %v: %v\n", os.Args[2], err)
+		os.Exit(1)
+	}
+	defer fto.Close()
+
+	err = scoutfs.MoveData(ffrom, fto)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "move blocks: %v\n", err)
+		os.Exit(1)
+	}
+}

scoutfs.go

@@ -10,6 +10,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"math"
 	"os"
@@ -716,3 +717,44 @@ func GetDF(f *os.File) (DiskUsage, error) {
 		FreeDataBlocks:  dataFree,
 	}, nil
 }
+
+// MoveData will move all of the extents in "from" file handle
+// and append to the end of "to" file handle.
+// The end of "to" must be 4KB aligned boundary.
+// errors this can return:
+// EINVAL: from_off, len, or to_off aren't a multiple of 4KB; the source
+//	   and destination files are the same inode; either the source or
+//	   destination is not a regular file; the destination file has
+//	   an existing overlapping extent.
+// EOVERFLOW: either from_off + len or to_off + len exceeded 64bits.
+// EBADF: from_fd isn't a valid open file descriptor.
+// EXDEV: the source and destination files are in different filesystems.
+// EISDIR: either the source or destination is a directory.
+// ENODATA: either the source or destination file have offline extents.
+func MoveData(from, to *os.File) error {
+	ffi, err := from.Stat()
+	if err != nil {
+		return fmt.Errorf("stat from: %v", err)
+	}
+	tfi, err := to.Stat()
+	if err != nil {
+		return fmt.Errorf("stat to: %v", err)
+	}
+
+	mb := moveBlocks{
+		From_fd:  uint64(from.Fd()),
+		From_off: 0,
+		Len:      uint64(ffi.Size()),
+		To_off:   uint64(tfi.Size()),
+	}
+
+	_, err = scoutfsctl(to, IOCMOVEBLOCKS, unsafe.Pointer(&mb))
+	if err != nil {
+		return err
+	}
+
+	from.Truncate(0)
+	from.Seek(0, io.SeekStart)
+
+	return nil
+}

scoutfsdefs.go

@@ -15,6 +15,7 @@ const IOCSEARCHXATTRS = 0x80387309
 const IOCSTATFSMORE = 0x8030730a
 const IOCDATAWAITERR = 0x8030730b
 const IOCALLOCDETAIL = 0x8010730c
+const IOCMOVEBLOCKS = 0x8020730d
 
 const QUERYINODESMETASEQ = 0x0
 const QUERYINODESDATASEQ = 0x1
@@ -132,5 +133,11 @@ type allocDetailEntry struct {
 	Flags		uint8
 	Pad_cgo_0	[6]byte
 }
+type moveBlocks struct {
+	From_fd		uint64
+	From_off	uint64
+	Len		uint64
+	To_off		uint64
+}
 
 const sizeofstatfsMore = 0x30