GFS2: Fix case where reservation finished at end of rgrp

One corner case which the original patch failed to take into
account was when there is a reservation which ended such that
the following block was one beyond the end of the rgrp in
question. This extra test fixes that case.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reported-by: Bob Peterson <rpeterso@redhat.com>
Tested-by: Bob Peterson <rpeterso@redhat.com>

fs/gfs2/rgrp.c

@@ -1596,6 +1596,12 @@ static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state,
 			n += (rbm->bi - initial_bi);
 			goto find_next;
 		}
+		if (ret == -E2BIG) {
+			index = 0;
+			rbm->offset = 0;
+			n += (rbm->bi - initial_bi);
+			goto res_covered_end_of_rgrp;
+		}
 		return ret;
 
 bitmap_full:	/* Mark bitmap as full and fall through */
@@ -1608,6 +1614,7 @@ static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state,
 		index++;
 		if (index == rbm->rgd->rd_length)
 			index = 0;
+res_covered_end_of_rgrp:
 		rbm->bi = &rbm->rgd->rd_bits[index];
 		if ((index == 0) && nowrap)
 			break;