[PATCH 03/28] xfs: work around bogus gcc warning in xfs_allocbt_init_cursor

Christoph Hellwig
2011-07-07T11:06:42Z

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GCC 4.6 complains about an array subscript is above array bounds when
using the btree index to index into the agf_levels array. The only
two indices passed in are 0 and 1, and we have an assert insuring that.

Replace the trick of using the array index directly with using constants
in the already existing branch for assigning the XFS_BTREE_LASTREC_UPDATE
flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Index: xfs/fs/xfs/xfs_alloc_btree.c
===================================================================
--- xfs.orig/fs/xfs/xfs_alloc_btree.c 2011-06-17 14:16:27.929065669 +0200
+++ xfs/fs/xfs/xfs_alloc_btree.c 2011-06-17 14:17:22.145729599 +0200
@@ -427,13 +427,16 @@ xfs_allocbt_init_cursor(

cur->bc_tp = tp;
cur->bc_mp = mp;
- cur->bc_nlevels = be32_to_cpu(agf->agf_levels[btnum]);
cur->bc_btnum = btnum;
cur->bc_blocklog = mp->m_sb.sb_blocklog;
-
cur->bc_ops = &xfs_allocbt_ops;
- if (btnum == XFS_BTNUM_CNT)
+
+ if (btnum == XFS_BTNUM_CNT) {
+ cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
cur->bc_flags = XFS_BTREE_LASTREC_UPDATE;
+ } else {
+ cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
+ }

cur->bc_private.a.agbp = agbp;
cur->bc_private.a.agno = agno;