>     AFAIK libc's pwrite() is the low-level (minimal) wrapper to the 
> linux Write system-call. There isn't the concept of sequential 
> read/write to a disk in the kernel and this paradigm is implemented by 
> the means of libc's write(). 

     I may be wrong here. What I actually remember is that, in the 
parameters received by the driver, there is an offset were to write to 
or read from. Therefore the current location is managed at a higher 
level, which may well be in the VFS and not in the libc. Sorry for that 
inacuracy.

     Didier