Undeletable files.

[Mikel Lechner]

bob at pds3 (Robert A. Earl) writes:

>In article <22347 at pasteur.Berkeley.EDU> c91a1-rd at amazon.Berkeley.EDU.UUCP (Raja (Reader)) writes:
>>I tried to remove an old, unwanted directory in the root system.
>>There werea couple of subdirectories in that directory, and no matter what 
>>commands I used, I just could not remove it. rm -R, rmdir, etc.  I then ran 
>>icheck and then fsck, and still no errors were reported.  Then, on 
>>doing an ls -ilR, I noted that the directories were circularly linked!
>>One of the subdirectories had the same inode number as it's parent.
>>I then ran clri, and tried to first remove that inode number only, and
>>then that inode nbr and the other sub-directory inode.  Both times I failed.

>If you have root permissions on your system, you should be able to use the
>'unlink' command to solve this one.  (Note:  I have just created and solved the
>problem you described on my SCO XENIX 386 2.3.2 system, SVR2 + BSD stuff)

I once this problem in an old release of SunOS (3.2 I think).  The unlink
command refused to delete a directory which was linked.  It turned
out that the system call to remove a directory tested for a link
count == 2 before attempting to delete the directory.  This was used
as a shortcut to avoid checking the directory to determine if it was really
empty.  However, in the case of a linked directory the link count for
an emtpy directory is > 2.

I deleted the problem directory by:

1)  bringing the system to single user,
2)  sync'ing the disks,
3)  clri'ing the offending inode,
4)  stopping the system and rebooting with a sync,
5)  running fsck on reboot which finds and fixes the filesystem errors,
    caused by the clri.


-- 
				If you explain so clearly that nobody
				can misunderstand, somebody will.
Mikel Lechner
Teradyne EDA, Inc.		UUCP:  mikel at teraida.UUCP