Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!tecate.mips.com!trevc
From: trevc@tecate.mips.com (Trevor Cotton)
Newsgroups: comp.sys.mips
Subject: Re: RISC/os 4.5[12] (and probably earlier) cpio bug
Message-ID: <2862@spim.mips.COM>
Date: 1 May 91 02:06:29 GMT
References: <2368@cluster.cs.su.oz.au>
Sender: news@mips.COM
Reply-To: trevc@mips.com
Organization: Mips Computer Systems Inc., Sunnyvale, CA
Lines: 48
Nntp-Posting-Host: tecate.mips.com

In article <2368@cluster.cs.su.oz.au>, bruce@cs.su.oz (Bruce Janson) writes:
|> Summary:
|> 	"cpio -pdm" sometimes fails to create empty directories.
|> 
|> Repeat by:
|> 	$ uname -a
|> 	joyce joyce 4_52 UMIPS mips
|> 	$ id
|> 	uid=0(root) gid=0(root)
|> 	$ cd /tmp; mkdir t f f/a f/a/b; cd f
|> 	$ find . -depth -print | cpio -pdm ../t
|> 	cpio: WARNING: Cannot change the mode of file "../t/a/b" to 16877.
|> 	cpio: WARNING: Cannot change owner to 0 and group to 0 for file "../t/a/b".
|> 	0 blocks
|> 	$ 

Because the -depth option to find is used, cpio will be fed 
./a/b and then ./a
Because the -d option to cpio is used, it will try and create the needed
directory 'a' first.

The problem is that cpio is doing a

if (!mkdir(namep, df_mode)) {

When trying to create the directory ../t/a

mkdir returns 0 on success, -1 on failure which means that cpio thinks it
managed to create the directory when it did not.
The reason it gives the "Cannot change the mode of file "../t/a/b" to 16877."
error message is actually because ../t/a/b does not exist.

Changing the offending line of code to

if (mkdir(namep, df_mode) == -1) {

cures the problem.

I will make sure that a bug report is submitted so that we can get this
fixed in the next release.

-- 
--trevc--

  Trevor Cotton, Sustaining Engineering, MIPS Computer Systems Inc.
  MS 6-05, 930 DeGuigne Drive, Sunnyvale, CA 94088-3650
  Tel: +1 408 524 7286  Fax: +1 408 524 7521
  Email: {wyse,ames,decwrl,pyramid}!mips!trevc    trevc@mips.com