Latest working kernel version:
Earliest failing kernel version:
Distribution:Scientific Linux 5.1 / Updated Kernel 
Hardware Environment: HP Proliant ML115
Software Environment: 2.6.19-92.el5 and 2.6.18-53 (default SL5.1 kernel)
Problem Description:

I installed a linux server based on SL 5.1 linux and run a backup using dump.

The effect was the the kernel panic'ed in map_bio() with 2.6.18-53.1.4.el5.
After I upgraded to 2.6.18-92 the system seem to hang.
Always after some time, ie. when 17% of the dump is done.

I do a dump level 0 (-b64) from a RAID 1 array mounted on /data to a
file in root fs in /backup. It's called /dev/mapper/nvidia_bcacfdbgp1
The system is in normal user mode, but also in single user mode.

Steps to reproduce:
/sbin/dump -0u -b64 -f /backup/data.0 /data

either in single or multiuser mode.

Maybe it has something todo with the -b option? I've created a few backups
before I introduced the -b64 option to improve the speed.
-b64 seems to panic always. Right now I start over with -b16.

EIP was pointing to map_bio(). 
Callstack which I could read of the console:
add_to_page_cache
__do_pache_cache_readahead
dm_any_congested
blockable_page_cache_readahead
make_ahead_window
page_cache_readahead
do_generic_mapping
__generic_file_io_read
file_read_actor
generic_file_read
auto_remove_wake_function
mutex_lock
block_lseek
vfs_read
sys_read
sys_call

Let me know if you need more information...

Thanks,
Alf