[PATCH] xfsprogs: Fix attr leaf block definition

[Jan Kara]

struct xfs_attr_leafblock contains 'entries' array which is declared
with size 1 altough it can in fact contain much more entries. Since this
array is followed by further struct members, gcc (at least in version
4.8.3) thinks that the delared size of the array is the real one and
thus optimizes away all accesses beyond the end of array resulting in
non-working code.

Signed-off-by: Jan Kara <jack at suse.com>
---
 include/xfs_da_format.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/xfs_da_format.h b/include/xfs_da_format.h
index 11f142078e12..39bfeb042844 100644
--- a/include/xfs_da_format.h
+++ b/include/xfs_da_format.h
@@ -1180,8 +1180,14 @@ typedef struct xfs_attr_leaf_name_remote {
 typedef struct xfs_attr_leafblock {
 	xfs_attr_leaf_hdr_t	hdr;	/* constant-structure header block */
 	xfs_attr_leaf_entry_t	entries[1];	/* sorted on key, not name */
+	/*
+	 * Definitions below are commented out so that gcc doesn't optimize
+	 * away accesses into 'entries' for indexes larger than 1
+	 */
+#if 0
 	xfs_attr_leaf_name_local_t namelist;	/* grows from bottom of buf */
 	xfs_attr_leaf_name_remote_t valuelist;	/* grows from bottom of buf */
+#endif
 } xfs_attr_leafblock_t;
 
 /*
-- 
2.1.4