1 files changed, 9 insertions, 1 deletions
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 370c29b536ea..66b6d4d8b1d2 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