[Cluster-devel] [GFS2 PATCH] GFS2: Reset rd_last_alloc when it reaches the end of the rgrp

[Steven Whitehouse]

Hi,

Both patches are now queued for the -nmw tree. Thanks,

Steve.

On Thu, 2012-12-20 at 13:23 -0500, Bob Peterson wrote:
> Hi,
> 
> In function rg_mblk_search, it's searching for multiple blocks in
> a given state (e.g. "free"). If there's an active block reservation
> its goal is the next free block of that. If the resource group
> contains the dinode's goal block, that's used for the search. But
> if neither is the case, it uses the rgrp's last allocated block.
> That way, consecutive allocations appear after one another on media.
> The problem comes in when you hit the end of the rgrp; it would never
> start over and search from the beginning. This became a problem,
> since if you deleted all the files and data from the rgrp, it would
> never start over and find free blocks. So it had to keep searching
> further out on the media to allocate blocks. This patch resets the
> rd_last_alloc after it does an unsuccessful search at the end of
> the rgrp.
> 
> Regards,
> 
> Bob Peterson
> Red Hat File Systems
> 
> Signed-off-by: Bob Peterson <rpeterso at redhat.com> 
> ---
>  fs/gfs2/rgrp.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
> index db2c423..7e668e0 100644
> --- a/fs/gfs2/rgrp.c
> +++ b/fs/gfs2/rgrp.c
> @@ -1428,6 +1428,9 @@ static void rg_mblk_search(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip,
>  		rs->rs_free = extlen;
>  		rs->rs_inum = ip->i_no_addr;
>  		rs_insert(ip);
> +	} else {
> +		if (goal == rgd->rd_last_alloc + rgd->rd_data0)
> +			rgd->rd_last_alloc = 0;
>  	}
>  }
>  
>