Re: [rdiff-backup-users] rdiff-backup, broken symlinks and python 2.4?

[Alexander 'Leo' Bergolth]

On 11/09/2008 10:54 AM, Andreas Olsson wrote:
> On Sunday 09 November 2008 04:17:45 Andrew Ferguson wrote:
> > On Nov 8, 2008, at 9:04 PM, Andreas Olsson wrote:
> > > When I upgraded my servers running Ubuntu 6.06 and Ubuntu 4.0 to use
> s/Ubuntu 4.0/Debian 4.0/
>
> > Try updating your version of python-pyxattr. What *should* be
> > happening is that the extended attribute calls are working on the
> > symlink, and not the target of the symlink. Since the warning makes
> > sense if the later is happening (target of the symlink), I suspect a
> > bug in python-pyxattr or lower. (Or maybe older Ubuntu don't even
> > support xattr on symlink).
>
> You are right, this is due to a bug in older versions of pyxattr. It seems to 
> have been fixed in pyxattr 0.2.2. Unfortunately Ubuntu 6.06 and Debian 4.0 
> supplies slightly older versions; 0.2 and 0.2.1, that is.
>
> When I installed the most recent version of pyxattr on an Ubuntu 6.06 system 
> it had no trouble properly handling extended attributes on symlinks.

I'm also experiencing problems with extended attributes on symlinks.
rdiff-backup even dies with an exception because listxattr returns 
garbage on some symlinks. (See the attached debugger excerpt.)

Maybe there should be a way to turn off xattrs on symlinks for use on 
systems stuck with old versions of pyxattr?

Cheers,
--leo
--
e-mail   ::: Leo.Bergolth (at) wu-wien.ac.at
fax      ::: +43-1-31336-906050
location ::: Computer Center | Vienna University of Economics | Austria

Exception '[Errno 34] Numerical result out of range' raised of class 
'exceptions.IOError':
  File "/usr/lib/python2.4/site-packages/rdiff_backup/robust.py", line 32, in 
check_common_error
    try: return function(*args)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 1123, in 
append
    return self.__class__(self.conn, self.base, self.index + (ext,))
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 868, in 
__init__
    else: self.setdata()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 893, in 
setdata
    if self.lstat(): self.conn.rpath.setdata_local(self)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 1470, in 
setdata_local
    if Globals.eas_conn: rpath.data['ea'] = ea_get(rpath)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/eas_acls.py", line 584, 
in rpath_ea_get
    ea.read_from_rp(rp)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/eas_acls.py", line 74, in 
read_from_rp
    try: self.attr_dict[attr] = rp.conn.xattr.getxattr(rp.path, attr, 
rp.issym())

Exception '[Errno 34] Numerical result out of range' raised of class 
'exceptions.IOError':
  File "/usr/lib/python2.4/site-packages/rdiff_backup/Main.py", line 304, in 
error_check_Main
    try: Main(arglist)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/Main.py", line 324, in 
Main
    take_action(rps)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/Main.py", line 280, in 
take_action
    elif action == "backup": Backup(rps[0], rps[1])
  File "/usr/lib/python2.4/site-packages/rdiff_backup/Main.py", line 343, in 
Backup
    backup.Mirror_and_increment(rpin, rpout, incdir)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/backup.py", line 51, in 
Mirror_and_increment
    DestS.patch_and_increment(dest_rpath, source_diffiter, inc_rpath)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/backup.py", line 241, in 
patch_and_increment
    for diff in rorpiter.FillInIter(source_diffiter, dest_rpath):
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rorpiter.py", line 177, 
in FillInIter
    for rp in rpiter:
  File "/usr/lib/python2.4/site-packages/rdiff_backup/backup.py", line 103, in 
get_diffs
    for dest_sig in dest_sigiter:
  File "/usr/lib/python2.4/site-packages/rdiff_backup/backup.py", line 166, in 
get_sigs
    for src_rorp, dest_rorp in cls.CCPP:
  File "/usr/lib/python2.4/site-packages/rdiff_backup/backup.py", line 320, in 
next
    source_rorp, dest_rorp = self.iter.next()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rorpiter.py", line 92, in 
Collate2Iters
    try: relem1 = riter1.next()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rorpiter.py", line 342, 
in next
    next_elem = self.iter.next()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/selection.py", line 132, 
in Iterate_fast
    try: rpath, val = diryield_stack[-1].next()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/selection.py", line 120, 
in diryield
    rpath.append, (filename,))
  File "/usr/lib/python2.4/site-packages/rdiff_backup/robust.py", line 32, in 
check_common_error
    try: return function(*args)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 1123, in 
append
    return self.__class__(self.conn, self.base, self.index + (ext,))
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 868, in 
__init__
    else: self.setdata()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 893, in 
setdata
    if self.lstat(): self.conn.rpath.setdata_local(self)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 1470, in 
setdata_local
    if Globals.eas_conn: rpath.data['ea'] = ea_get(rpath)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/eas_acls.py", line 584, 
in rpath_ea_get
    ea.read_from_rp(rp)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/eas_acls.py", line 74, in 
read_from_rp
    try: self.attr_dict[attr] = rp.conn.xattr.getxattr(rp.path, attr, 
rp.issym())

Traceback (most recent call last):
  File "/usr/bin/rdiff-backup", line 44, in ?
    rdiff_backup.Main.error_check_Main(sys.argv[1:])
  File "/usr/lib/python2.4/site-packages/rdiff_backup/Main.py", line 304, in 
error_check_Main
    try: Main(arglist)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/Main.py", line 324, in 
Main
    take_action(rps)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/Main.py", line 280, in 
take_action
    elif action == "backup": Backup(rps[0], rps[1])
  File "/usr/lib/python2.4/site-packages/rdiff_backup/Main.py", line 343, in 
Backup
    backup.Mirror_and_increment(rpin, rpout, incdir)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/backup.py", line 51, in 
Mirror_and_increment
    DestS.patch_and_increment(dest_rpath, source_diffiter, inc_rpath)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/backup.py", line 241, in 
patch_and_increment
    for diff in rorpiter.FillInIter(source_diffiter, dest_rpath):
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rorpiter.py", line 177, 
in FillInIter
    for rp in rpiter:
  File "/usr/lib/python2.4/site-packages/rdiff_backup/backup.py", line 103, in 
get_diffs
    for dest_sig in dest_sigiter:
  File "/usr/lib/python2.4/site-packages/rdiff_backup/backup.py", line 166, in 
get_sigs
    for src_rorp, dest_rorp in cls.CCPP:
  File "/usr/lib/python2.4/site-packages/rdiff_backup/backup.py", line 320, in 
next
    source_rorp, dest_rorp = self.iter.next()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rorpiter.py", line 92, in 
Collate2Iters
    try: relem1 = riter1.next()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rorpiter.py", line 342, 
in next
    next_elem = self.iter.next()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/selection.py", line 132, 
in Iterate_fast
    try: rpath, val = diryield_stack[-1].next()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/selection.py", line 120, 
in diryield
    rpath.append, (filename,))
  File "/usr/lib/python2.4/site-packages/rdiff_backup/robust.py", line 32, in 
check_common_error
    try: return function(*args)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 1123, in 
append
    return self.__class__(self.conn, self.base, self.index + (ext,))
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 868, in 
__init__
    else: self.setdata()
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 893, in 
setdata
    if self.lstat(): self.conn.rpath.setdata_local(self)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/rpath.py", line 1470, in 
setdata_local
    if Globals.eas_conn: rpath.data['ea'] = ea_get(rpath)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/eas_acls.py", line 584, 
in rpath_ea_get
    ea.read_from_rp(rp)
  File "/usr/lib/python2.4/site-packages/rdiff_backup/eas_acls.py", line 74, in 
read_from_rp
    try: self.attr_dict[attr] = rp.conn.xattr.getxattr(rp.path, attr, 
rp.issym())
IOError: [Errno 34] Numerical result out of range

> /usr/lib/python2.4/site-packages/rdiff_backup/eas_acls.py(79)read_from_rp()


(Pdb) rp.path
'/usr/share/man/man1/lpq.1.gz'
(Pdb) attr
''
(Pdb) rp.issym()
True
(Pdb) attr_list
('', '', '', '', '\xe0+\x90\xb7\xe0[\xf6\xb7)', '', '', 
'l\x16\xb2\t\xd4\\\xcf\t\xe41\xe5\t')
(Pdb) rp.conn.xattr.listxattr(rp.path, rp.issym())
('', '', '', '', '\xff\xff\xff\xff', '', '', '', ')', '', '', 
'\xdcd\x9f\t\x04\xea\x7f\t\xdcT\xf2\t')
(Pdb) rp.conn.xattr.listxattr(rp.path, False)
()

# getfattr -h -d /usr/share/man/man1/lpq.1.gz
# getfattr -d /usr/share/man/man1/lpq.1.gz