Are Bio's blocks physically contiguous?

["Bao zhao" <paozhaokeats@xxxxxxxxxxx>]

  In one bio, all the page's virtual addresses needn't be contiguous,but 
their mapping in disk must be  contiguous, is this right?
 For ext2 fs,ext2_readpage call  mpage_readpage,mpage_readpage must check 
that the physical blocks of the page is contiguous,if contiguous,then use 
one bio, otherwise ,call block_read_full_page. my question is: is this 
decision right?The default block size is 1kB,  are most pages'  blocks    
physically contiguous? if not , why don't call block_read_full_page 
directly?
   Thanks in advance for anyone's reply.

_________________________________________________________________
Add photos to your messages with MSN 8. Get 2 months FREE*. 
http://join.msn.com/?page=features/featuredemail


--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive:       http://mail.nl.linux.org/kernelnewbies/
FAQ:           http://kernelnewbies.org/faq/