Re: set blksize of block device

["Shesha B. " Sreenivasamurthy <shesha@inostor.com>]

Firstly you cannot set the block size to lesser than 512. 

When there is a request for the IO, you populate "struct req" data
structure which you will pass it to the kernel or lower level SCSI/SATA
driver. In the "struct req" there is a field "b_size" which may be what
you are interested in. At the user level you can use the IOCTLs to set
the block size of the RAW block device.

-Shesha

On Wed, 2004-10-27 at 18:44, Lei Yang wrote:
> If nobody could answer this question, what about another one? Is there a 
> system call or a kernel interface that would allow me to write a block 
> of data to block 1 of a certain block device?
> 
> Thanks for your reply in advance!
> 
> Lei
> 
> Lei Yang wrote:
> 
> > Please cc me if you have answers to this, I am not on the list. Thanks 
> > a lot!
> >
> > Lei Yang wrote:
> >
> >> Hello,
> >>
> >> I am learning block device drivers and have a newbie question. Given 
> >> a block device, is there anyway that I could set its block size? For 
> >> example, I want to write a block device driver that will work on an 
> >> existing block device.  In this driver, I want block size smaller. 
> >> (The idea looks confusing but I could explain if anybody is 
> >> interested :- )  However,  typically the block size is 1KB, now I 
> >> want to set it to 512 or 256.  Can I do it?
> >>
> >> TIA
> >> Lei
> >>
> >
> >
> >
> 
> 
> 
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