[Xen-devel] problems of 'blktap'

[李敏 <fly.limin@xxxxxxxxx>]

when I am studying blktap mechanism , I faced a problem that I can't understand.

In tapdisk.c(xen-3.3.0/tools/blktap/drivers) line 687-689

 

page  = (char *)MMAP_VADDR(info->vstart,
         (unsigned long)req->id, i);
   page += (req->seg[i].first_sect << SECTOR_SHIFT);

 

how was the page address caculated?  I am not quite understanding.

thanks a lot!
--
Min Li
School of Computer Science and Technology
Cluster and Grid Computing Lab
Services Computing Technology and System Lab
Huazhong University of Science and Technology
Wuhan, 430074, China
Tel: 13986251431 027-65236831
Email: fly.limin@xxxxxxxxx

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