From: Andreas Dilger <adilger@sun.com>
Subject: Re: [PATCH -v2] ext4: Use inode preallocation with -o noextents
Date: Thu, 05 Jun 2008 12:28:30 -0600
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Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
	cmm@us.ibm.com, sandeen@redhat.com, linux-ext4@vger.kernel.org
To: Theodore Tso <tytso@mit.edu>
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On Jun 05, 2008  11:37 -0400, Theodore Ts'o wrote:
> This is better, but it still means that we are exporting a large
> number of functions to the callers.  It's not clear to me we need so
> many different variants of ext4_new_blocks_* --- what is their
> justification to exist?
> 
> For example, why not just have:
> 
> static ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
>        				ext4_lblk_t iblock, ext4_fsblk_t goal,
> 				unsigned long *count, int *errp, int meta)
> 
> where if inode is NULL, then you're allocating a metadata block, and
> if count is NULL, then you only want one block.  Of course, this needs
> to be carefully documented at the function.

I don't necessarily agree that meta should be implied by inode != NULL.
We do want to cluster metadata allocations for a single inode if possible,
so keeping the inode information is useful.  We may want to keep a separate
"metadata goal block" from the "data goal block" in the inode...

That said, it seems you still have a "meta" parameter here?  I always hate
having an int for a boolean, and we may as well make this a "flags" so
that when we want to improve it later we don't need to rename it and change
all of the "1" parameters to "EXT4_META_BLOCK".  Do it right the first time.

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