Re: [PATCH] ext4: Rework the ext4_da_writepages

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

On Thu, Jul 31, 2008 at 11:03:25PM +0530, Aneesh Kumar K.V wrote:
> With the below changes we reserve credit needed to insert only one extent
> resulting from a call to single get_block. That make sure we don't take
> too much journal credits during writeout. We also don't limit the pages
> to write. That means we loop through the dirty pages building largest
> possible contiguous block request. Then we issue a single get_block request.
> We may get less block that we requested. If so we would end up not mapping
> some of the buffer_heads. That means those buffer_heads are still marked delay.
> Later in the writepage callback via __mpage_writepage we redirty those pages.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Tested with 
a) fsstress with falloc
b) fsxlinux with falloc
c) fs_inode
d) ffsb
e) cp -ax / .

with fsck after each test

-aneesh