freebsd stable - Apr 2009 - bdes: fwrite error at 8

Hi,

I'm doing encrypted nightly dumps over the network to an NFS file  
system, i.e., dump | bzip2 | bdes > nfs.

Since about a week ago, I see occasional errors from bdes ("bdes:  
fwrite error at 8"). Anyone have a hunch what's going on here? I'm
wondering if this is something that started when I upgraded to 7.2- 
PRERELEASE...

Thanks,
Lars

Dumping /usr to /mnt/backup/fit.usr.3.20090408.dump.bz2.des
  DUMP: Date of this level 3 dump: Wed Apr  8 03:30:18 2009
  DUMP: Date of last level 2 dump: Tue Apr  7 03:29:44 2009
  DUMP: Dumping snapshot of /dev/mfid0s1f (/usr) to standard output
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 7237937 tape blocks.
  DUMP: dumping (Pass III) [directories]
  DUMP: dumping (Pass IV) [regular files]
  DUMP: 13.89% done, finished in 0:31 at Wed Apr  8 04:09:30 2009
  DUMP: 20.69% done, finished in 0:38 at Wed Apr  8 04:21:50 2009
  DUMP: 25.17% done, finished in 0:44 at Wed Apr  8 04:33:06 2009
  DUMP: 29.66% done, finished in 0:47 at Wed Apr  8 04:40:56 2009
  DUMP: 34.16% done, finished in 0:48 at Wed Apr  8 04:46:41 2009
bdes: fwrite error at 8
  DUMP: 38.56% done, finished in 0:47 at Wed Apr  8 04:51:17 2009
  DUMP: 42.96% done, finished in 0:46 at Wed Apr  8 04:54:58 2009
  DUMP: 47.47% done, finished in 0:44 at Wed Apr  8 04:57:45 2009
  DUMP: 51.95% done, finished in 0:41 at Wed Apr  8 05:00:07 2009
  DUMP: 56.44% done, finished in 0:38 at Wed Apr  8 05:02:05 2009
  DUMP: 60.96% done, finished in 0:35 at Wed Apr  8 05:03:45 2009
  DUMP: 65.47% done, finished in 0:31 at Wed Apr  8 05:05:10 2009
  DUMP: 70.01% done, finished in 0:27 at Wed Apr  8 05:06:22 2009
  DUMP: 74.51% done, finished in 0:23 at Wed Apr  8 05:07:28 2009
  DUMP: 79.01% done, finished in 0:19 at Wed Apr  8 05:08:26 2009
  DUMP: 83.86% done, finished in 0:15 at Wed Apr  8 05:08:55 2009
bdes: fwrite error at 8
  DUMP: 91.89% done, finished in 0:07 at Wed Apr  8 05:06:01 2009
  DUMP: DUMP: 7223390 tape blocks
  DUMP: finished in 5335 seconds, throughput 1353 KBytes/sec
  DUMP: level 3 dump on Wed Apr  8 03:30:18 2009
  DUMP: DUMP IS DONE

In the last episode (Apr 08), Lars Eggert said:
> I'm doing encrypted nightly dumps over the network to an NFS file
system,
> i.e., dump | bzip2 | bdes > nfs.
> 
> Since about a week ago, I see occasional errors from bdes ("bdes:  
> fwrite error at 8"). Anyone have a hunch what's going on here?
I'm
> wondering if this is something that started when I upgraded to 7.2- 
> PRERELEASE...
[..]
>   DUMP: 34.16% done, finished in 0:48 at Wed Apr  8 04:46:41 2009
> bdes: fwrite error at 8
>   DUMP: 38.56% done, finished in 0:47 at Wed Apr  8 04:51:17 2009
Two bugs:  if fwrite fails, there's no sense in continuing to encrypt, and
it should print the error it got.  Apply this patch and try again:

Index: bdes.c
==================================================================RCS file:
/home/ncvs/src/secure/usr.bin/bdes/bdes.c,v
retrieving revision 1.9
diff -u -r1.9 bdes.c
--- bdes.c	10 Feb 2005 14:47:06 -0000	1.9
+++ bdes.c	8 Apr 2009 14:32:43 -0000
@@ -112,7 +112,7 @@
 #define	READ(buf, n)	fread(buf, sizeof(char), n, stdin)
 #define WRITE(buf,n)						\
 		if (fwrite(buf, sizeof(char), n, stdout) != n)	\
-			warnx("fwrite error at %d", n);
+			err(1, "fwrite error at %d", n);
 
 /*
  * global variables and related macros


After patching, the following test commands should print a single usefull
error instead of a stream of useless ones.

$ trap '' PIPE 
$ bdes -k asd < /boot/kernel/kernel | dd of=/dev/null count=1

-- 
	Dan Nelson
	dnelson@allantgroup.com

On 2009-4-8, at 17:46, Dan Nelson wrote:
> bdes -k asd < /boot/kernel/kernel | dd of=/dev/null count=1
# bdes -k asd < /boot/kernel/kernel | dd of=/dev/null count=1
1+0 records in
1+0 records out
512 bytes transferred in 0.000860 secs (595366 bytes/sec)
bdes: fwrite error at 8: Broken pipe

Lars