Bug#324724: linux-image-2.6.12-1-686: dismally slow throughput to usb flash drive

[Chris Roddy <croddy@emory.edu>]

i experimented with different usb ports, filesystems and mount options
on the device. i have only been able to find one factor to which to
attribute the slow write behavior:

it appears that this is in some way related to the 'sync' mount option.
when the device is mounted without the sync option, write speeds are
very much in the normal usb2.0 range. when mounted with the sync option,
write speed drops to around 24kB/s.

of course, *some* slowdown is expected when a device is mounted 'sync',
but something else is wrong here -- writing the file and then
immediately unmounting the device (which should flush all remaining
writes to disk) is still much, much faster than just writing the file
when mounted sync.