endless loop in /usr/bin/find ?

[Dave Howorth]

I have a weird problem and am wondering if anybody has seen it before -
find seems to be in an infinite loop. I'm running on Suse9.2. kernel 
2.6.8-24.14-smp. findutils 4.1.20-2 x86_64. Dual processor Xeon.

I ran a Perl script, which in turn ran find. The Perl script belongs to 
a package called dirvish and this job has previously worked fine every 
night. I don't think the Perl code is a factor, but here's the relevant 
line:

   open(FIND, "find $destree -ls|") or seppuku 21, "dirvish
$vault:$image cannot build index";

Here's what I can see on the system.

 From ps, here are the commands:

root      5042  4820  0 Jun15 ?        00:00:01 /usr/bin/perl
/usr/local/sbin/dirvish --vault pcx36-var --image-time 22:00

root      5106  5042 99 Jun15 ?        1-05:49:36 find
/backup/pcx36/pcx36-var/2005-06-14/tree -ls

 From top, find seems to be very busy doing something:

   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  5106 root      39  15  2928  528 2752 R 99.9  0.0   1792:15 find

 From strace, find isn't interacting with the system at all. In 
particular it's not examining files or directories :(

suse1:~ # strace -p 5042
Process 5042 attached - interrupt to quit
read(11,

suse1:~ # strace -p 5106
Process 5106 attached - interrupt to quit

(no output despite leaving it for quite a while, so my conclusion is
that find is in an infinite loop)

 From lsof, to be sure it really is /usr/bin/find:

suse1:~ # lsof -p 5106
COMMAND  PID USER   FD   TYPE DEVICE    SIZE     NODE NAME
find    5106 root  cwd    DIR  253,5     744   793554
/backup/pcx36/pcx36-var/2005-06-14/tree/www
find    5106 root  rtd    DIR    3,1     680        2 /
find    5106 root  txt    REG    3,1   66216    36947 /usr/bin/find
find    5106 root  mem    REG    3,1  106608    20736 /lib64/ld-2.3.3.so
find    5106 root  mem    REG    3,1  217016   164645 /var/run/nscd/passwd
find    5106 root  mem    REG    3,1  217016   164652 /var/run/nscd/group
find    5106 root  mem    REG    3,1 1412174    20761 /lib64/tls/libc.so.6
find    5106 root    0r  FIFO    0,7         32522573 pipe
find    5106 root    1w  FIFO    0,7         33987450 pipe
find    5106 root    2w   REG    3,1    2256   164546
/tmp/run-crons.ZY4693/run-crons.daily.4691
find    5106 root    3r   DIR    3,1     848    13368 /root

Has anyone seen anything like this?

To me it looks like find is in an infinite loop. Any ideas on how to 
extract more information before I finally give up and kill the process?

I've asked about this on the dirvish list and the suse list but got no 
feedback. I don't know how to subscribe to this list so please copy me 
on any replies.

Thanks and regards, Dave