sorry but my question it seems wsnt clear ... as my ques was suppose i have this function
blk_queue_hardsect_size(request_queue_t *queue , unsigned short max ); or some other function takes sector as parameter there in any of these functions how do i decide that whether i should send number sectors in terms of 512 bytes or in terms of my hardware size 2048 bytes .... how do i know that in this function communication is between kernel to block layer or from block layer to driver as in book they just write this "All request generated by kernel are multiple of hardware sect size and properly aligned All the communication from block layer and driver is in 512 bytes" as struct request req i get in request function .... what should i assume of req->current_nr_sectors are they 512 byte sectors or 2048 byte sectors pl clarify ....hope i m making sense.. On Sun, Feb 1, 2009 at 3:20 PM, nidhi mittal <nidhimitta...@gmail.com>wrote: > 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 > -- Thanks & Regards Nidhi
