[Cluster-devel] [GFS2 PATCH] GFS2: Stop block extents at the end of bitmaps

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

On Tue, 2012-08-28 at 08:45 -0400, Bob Peterson wrote:
> Hi,
> 
> This patch stops multiple block allocations if a nonzero
> return code is received from gfs2_rbm_from_block. Without
> this patch, if enough pressure is put on the file system,
> you get a kernel warning quickly followed by:
> BUG: unable to handle kernel NULL pointer dereference at (null)
> IP: [<ffffffffa04f47e8>] gfs2_alloc_blocks+0x2c8/0x880 [gfs2]
> With this patch, things run normally.
> 
> Regards,
> 

Now in the -nmw tree. Thanks,

Steve.


> Bob Peterson
> Red Hat File Systems
> 
> Signed-off-by: Bob Peterson <rpeterso@redhat.com> 
> ---
> diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
> index 87ee0b7..081fba8 100644
> --- a/fs/gfs2/rgrp.c
> +++ b/fs/gfs2/rgrp.c
> @@ -1852,8 +1852,7 @@ static void gfs2_alloc_extent(const struct gfs2_rbm *rbm, bool dinode,
>  	block++;
>  	while (*n < elen) {
>  		ret = gfs2_rbm_from_block(&pos, block);
> -		WARN_ON(ret);
> -		if (gfs2_testbit(&pos) != GFS2_BLKST_FREE)
> +		if (ret || gfs2_testbit(&pos) != GFS2_BLKST_FREE)
>  			break;
>  		gfs2_trans_add_bh(pos.rgd->rd_gl, pos.bi->bi_bh, 1);
>  		gfs2_setbit(&pos, true, GFS2_BLKST_USED);
>