[Cluster-devel] [PATCH 3/3] gfs2: Don't create unnecessary indirect blocks

[Bob Peterson <rpeterso@redhat.com>]

Hi,

----- Original Message -----
> When gfs2 increases the height of an inode, it always creates an
> indirect block for each the new level of indirection, even when the
> inode is entirely empty.  For example, these commands:
> 
>   $ mkfs.gfs2 -O -b 4096 -p lock_nolock /dev/vdb
>   $ mount /dev/vdb /mnt/test/
>   $ xfs_io -f -c 'truncate 0' -c 'pwrite 509b 4k' /mnt/test/foo
> 
> will create a pointer to an entirely empty indirect block.  This is
> unnecessary, so fix the code to avoid that.  While at it, clean things
> up and add some more documentation.
> 
> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
> ---
(snip)
> +	bool overlap = false;

Can we change overlap to be unsigned or something? Although technically
there's nothing wrong with doing so, arithmetic with a bool just rubs
me the wrong way.

(snip)
> +				i = 1 + overlap;

This patch is a little more cryptic. I'll have to look at it again
when I'm fresh.

Regards,

Bob Peterson