Diff b/w generic_file_read & do_sync_read

Diff b/w generic_file_read & do_sync_read

[UZAIR LAKHANI]

Hello All,

I want to find out the difference between
generic_file_read and do_sync_read. The thing I have
got upto now is that generic_file_read uses the page
cache for doing read therefore we must implement
readpage function with generic_file_read. 

On the other hand do_sync_read uses aio_read function
for doing read. I want a little bit explanation about
the difference b/w these two.

Thanks,
Uzair Lakhani,
Karachi, Pakistan.

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

Re: Diff b/w generic_file_read & do_sync_read

[Dave Kleikamp]

On Wed, 2006-08-23 at 07:11 -0700, UZAIR LAKHANI wrote:
> Hello All,
> 
> I want to find out the difference between
> generic_file_read and do_sync_read. The thing I have
> got upto now is that generic_file_read uses the page
> cache for doing read therefore we must implement
> readpage function with generic_file_read. 
> 
> On the other hand do_sync_read uses aio_read function
> for doing read. I want a little bit explanation about
> the difference b/w these two.

There really isn't too much difference between the two.  There is a set
of patches in the -mm kernel that cleans up some of the duplicity and
removes generic_file_read completely:
http://marc.theaimsgroup.com/?l=linux-kernel&m=115214448319794&w=2

Shaggy
-- 
David Kleikamp
IBM Linux Technology Center