hello
i was writing my initial block device driver following LDD
but was totally confused on KERNEL SECTOR SIZE and hardware sector size issue they discussed in that .
they write sth like
if sector number passed between kernel and block layer it should be something and
if its passed between blocklayer and driver it should be something else.
means at different place some confusing note abt sector size
can someone clear it to me in simple 2-3 sentences
At what places , in which function i shd consider sending sector size with a thought that
at this place it understand sector= 512 bytes
and
At what places , in which function i shd consider sending sector size as my hardware sector size
in thinking that it understand 2048 bytes ...
and
most important
in book they write
blk_queue_hardsect_size(request_queue_t *queue , unsigned short max );
"All the communication from block layer and driver is in 512 bytes but all request generated by kernel are multiple of
hardware sect size and properly aligned "
so i wanted to know where actually is block layer and where is driver
where are they separated how do i know when i m going from block layer to driver ....
what i understand is ONLY user space and kernel space
it will be very kind if someone clears it to me.
thanks
Nidhi
Thanks & Regards
Nidhi
Nidhi
