Re: Reiser4 SCSI Bug?

[Hans Reiser <reiser@namesys.com>]

Thanks Isaac!

Does IDE have a different maximum?  Is there a non-hack way to discover
the maximum of the device driver underneath?

Hans

Isaac Chanin wrote:

>Steve Olivieri wrote:
>  
>
>>Greetings!
>>
>>I have a Maxtor Atlas II 15k, 147GB SCSI hard disk and an LSI Logic
>>LSI21320 Ultra320 SCSI Host Bus Adapter for PCI-X (though it's running in
>>a PCI slot).  I have partitioned it and installed a temporary Gentoo
>>system with the reiserfs filesytem.  My boot partition uses ext2.  These
>>partitions seem perfectly stable.  I have booted this temporary system
>>multiple times and I have attempted to use it to install a permanent
>>system with the reiser4 filesystem.
>>
>>After making the fileystems on each partition and mounting them, I was
>>able to download two tarballs (the stage and portage snapshot).  While
>>extracting the first, the terminal seems to hang.
>>
>>I switched to another terminal to see what was wrong.  Everything works
>>great until I try to do anything at all on a reiser4 partition.  Then,
>>this terminal also hangs.  Repeat until I'm out of terminals.
>>
>>I've been able to repeat this problem a number of times.  The only
>>messages in my log file claimed that a flush failed (with code -12, if I
>>remember correctly).  I do not have access to the logs at this time but I
>>will try to get them soon.
>>
>>I am running a 2.6.13-ck8 kernel patched with the 2.6.13 reiser4 patchset.
>> Patitions were made using the 1.0.5 reiser4progs/libaal.  In the past, I
>>have also replicated this problem using a 2.6.12-gentoo kernel with the
>>2.6.12 patchset and 1.0.5 reiser4progs/libaal.
>>
>>Is there something that I can do to fix this problem?  Is it a known bug?
>>
>>Also, I am not on the mailing list and I would appreciate it if I could be
>>cc'd with any information about this problem.
>>
>>Thanks,
>>Steve
>>
>>
>>
>>
>>    
>>
>
>Hey Steve,
>
>The problem appears to be in the fs/reiser4/wander.c file.  In short,
>nr_blocks passed to bio_alloc ends up being too big; in my testing 1024,
>whereas the maximum the called functions will properly deal with is 256.
>
>The attached patch adds a hacky fix for this problem, but perhaps someone
>who knows the code better should go through and take a look why max_blocks
>and nr in write_jnodes_to_disk_extent in wander.c do not always have a
>shared minimum of no greater than 256.
>
>Hope this helps,
>Isaac
>  
>
>------------------------------------------------------------------------
>
>--- /mnt/gentoo/usr/src/linux/fs/reiser4/wander.c	2005-10-28 19:27:02.301541280 -0400
>+++ linux/fs/reiser4/wander.c	2005-10-28 19:29:37.000000000 -0400
>@@ -1241,7 +1241,7 @@
> 
> 	while (nr > 0) {
> 		struct bio *bio;
>-		int nr_blocks = min(nr, max_blocks);
>+		int nr_blocks = min(min(nr, max_blocks), 256);
> 		int i;
> 		int nr_used;
> 
>