help in block drivers

Rahul Theraja rahul.theraja at gmail.com
Fri Oct 20 02:23:24 EST 2006


Hello Shakthi Kannan,

Thanks for the reply .

> driver. I could not understand why the "sbd_request " is called even
> though
> > i have given only one read call from user space file.
>
> Block device I/O transfer is done in blocks.
>
> >  And also in the driver, in the function sbd_request() how does the
> driver
> > get the parameters  like sector, current_nr_sectors and buffer.
>
> VFS <-> SCSI <-> Block device?
>
> > i could move
> > furhter fastly.
>
> Fastly? IMHO, learning kernel development involves lot of patience.
>
> SK



Is it necessary to use kernel_thread() in block drivers. In  drivers/block
loop.c i could see  kernel_thread() being used but in floopy.c it is not
used. When is this kernel_thread() function is supposed to be used ?  In the
sbd_device also the kernel_thread() is not used.

Anyone please kindly clarify my doubts.

Thanks in Advance

-Rahul
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