From 9a3f236d40a99ea8dca3df40d8ef67631057cad6 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Mon, 23 Aug 2010 11:49:34 +0100 Subject: GFS2: Add a bug trap in allocation code This adds a check to ensure that if we reach the block allocator that we don't try and proceed if there is no alloc structure hanging off the inode. This should only happen if there is a bug in GFS2. The error return code is distinctive in order that it will be easily spotted. Signed-off-by: Steven Whitehouse --- fs/gfs2/rgrp.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'fs/gfs2') diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 370c29b536e..66b6d4d8b1d 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -1496,11 +1496,19 @@ int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n) struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct buffer_head *dibh; struct gfs2_alloc *al = ip->i_alloc; - struct gfs2_rgrpd *rgd = al->al_rgd; + struct gfs2_rgrpd *rgd; u32 goal, blk; u64 block; int error; + /* Only happens if there is a bug in gfs2, return something distinctive + * to ensure that it is noticed. + */ + if (al == NULL) + return -ECANCELED; + + rgd = al->al_rgd; + if (rgrp_contains_block(rgd, ip->i_goal)) goal = ip->i_goal - rgd->rd_data0; else -- cgit v1.2.3-18-g5258