Re: [PATCH -v2] ext4: Use inode preallocation with -o noextents

[Mingming Cao <cmm@us.ibm.com>]

On Thu, 2008-06-05 at 12:24 -0600, Andreas Dilger wrote:
> On Jun 05, 2008  07:55 -0700, Mingming Cao wrote:
> > >  /**
> > > - * ext4_new_blocks_old() -- core block(s) allocation function
> > > + * ext4_orlov_new_blocks() -- core block(s) allocation function
> > 
> > what is orlov means? this is core function for non extent based without
> > mballoc block allocation, right? 
> 
> Orlov is the name of the INODE allocator, not the block allocator.  I'm
> not sure there is a name for the block allocator except "old" or "bitmap".

I think rename it as ext4_old_new_blocks() seems better, better than
orlov. This is the block allocator that is only used when mballoc is
turned off. I think we should update the function description.

> In the future I suspect we won't want to keep this version at all, using
> the mballoc allocator even for block-mapped files, but it is useful for
> now for performance comparisons.

In fact I found the mballoc is enabled even for block-mapped files. what
Aneesh's patch "Use inode preallocation with -o noextents" does is
enable the per-inode in-core preallocation for block allocation for
block-mapped files, whem mballoc is turned on. Without this patch, there
is not old ext3 block reservation(as mblloc turned off ext3 block
reservation automatically) and non in-core preallocation in the new
mballoc.

Anessh, Could you clarify this and update in the change log? 

> Cheers, Andreas
> --
> Andreas Dilger
> Sr. Staff Engineer, Lustre Group
> Sun Microsystems of Canada, Inc.
> 
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