btrfs-progs/bcp

#!/usr/bin/env python
# Copyright (C) 2007 Oracle.  All rights reserved.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public
# License v2 as published by the Free Software Foundation.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
# 
# You should have received a copy of the GNU General Public
# License along with this program; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 021110-1307, USA.
#
import sys, os, stat, fcntl
from optparse import OptionParser

def copylink(srcname, dst, filename, statinfo):
    dstname = os.path.join(dst, filename)
    if not os.path.exists(dstname):
        link_target = os.readlink(srcname)
        os.symlink(link_target, dstname)

def copydev(srcname, dst, filename, statinfo):
    devbits = statinfo.st_mode & (stat.S_IFBLK | stat.S_IFCHR)
    mode = stat.S_IMODE(statinfo.st_mode) | devbits
    dstname = os.path.join(dst, filename)
    if not os.path.exists(dstname):
        os.mknod(dstname, mode, statinfo.st_rdev)

def copyfile(srcname, dst, filename, statinfo):
    written = 0
    dstname = os.path.join(dst, filename)

    try:
        os.unlink(dstname)
    except:
        pass

    if options.link:
        os.link(srcname, dstname)
        return

    dstf = file(dstname, 'w')
    srcf = file(srcname, 'r')

    ret = 1

    try:
        if not options.copy:
            ret = fcntl.ioctl(dstf.fileno(), 1074041865, srcf.fileno())
    except:
        pass

    if ret != 0:
        while True:
            buf = srcf.read(256 * 1024)
            if not buf:
                break
            written += len(buf)
            dstf.write(buf)

    os.chmod(dstname, stat.S_IMODE(statinfo.st_mode))
    os.chown(dstname, statinfo.st_uid, statinfo.st_gid)


usage = "usage: %prog [options]"
parser = OptionParser(usage=usage)
parser.add_option("-l", "--link", help="Create hard links", default=False,
                  action="store_true")
parser.add_option("-c", "--copy", help="Copy file bytes (don't cow)",
                  default=False, action="store_true")

(options,args) = parser.parse_args()

if len(args) < 2:
    sys.stderr.write("source or destination not specified\n")
    sys.exit(1)

if options.link and options.copy:
    sys.stderr.write("Both -l and -c specified, using copy mode\n")
    options.link = False


src = args[0]
dst = args[1]

if not os.path.exists(dst):
    os.makedirs(dst)

iter = os.walk(src, topdown=True)

for (dirpath, dirnames, filenames) in iter:
    for x in dirnames:
        srcname = os.path.join(dirpath, x)
        statinfo = os.lstat(srcname)

        if srcname.startswith(src):
            part = srcname[len(src) + 1:]

        if stat.S_ISLNK(statinfo.st_mode):
            copylink(srcname, dst, part, statinfo)
            continue

        dst_dir = os.path.join(dst, part)
        if not os.path.exists(dst_dir):
            os.makedirs(dst_dir)

        os.chmod(dst_dir, stat.S_IMODE(statinfo.st_mode))
        os.chown(dst_dir, statinfo.st_uid, statinfo.st_gid)

    for f in filenames:
        srcname = os.path.join(dirpath, f)
        if srcname.startswith(src):
            part = srcname[len(src) + 1:]

        statinfo = os.lstat(srcname)
        st_mode = statinfo.st_mode

        if stat.S_ISLNK(st_mode):
            copylink(srcname, dst, part, statinfo)

        elif stat.S_ISBLK(st_mode) or stat.S_ISCHR(st_mode):
            copydev(srcname, dst, part, statinfo)

        elif stat.S_ISREG(st_mode):
            copyfile(srcname, dst, part, statinfo)