xfs: Zero initialize highstale and lowstale in xfs_dir2_leafn_add

nathanchance · djwong · commit 7be73fa1c1b0 · 2019-03-08T14:24:43.000-08:00
When building with -Wsometimes-uninitialized, Clang warns: fs/xfs/libxfs/xfs_dir2_node.c:481:6: warning: variable 'lowstale' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] fs/xfs/libxfs/xfs_dir2_node.c:481:6: warning: variable 'highstale' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] While it isn't technically wrong, it isn't a problem in practice because highstale and lowstale are only initialized in xfs_dir2_leafn_add when compact is not zero then they are passed to xfs_dir3_leaf_find_entry, where they are initialized before use when compact is zero. Regardless, it's better not to be passing around uninitialized stack memory so zero initialize these variables, which silences this warning. Link: ClangBuiltLinux#393 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/libxfs/xfs_dir2_node.c b/fs/xfs/libxfs/xfs_dir2_node.c
@@ -444,6 +444,8 @@ xfs_dir2_leafn_add(
 
 	dp = args->dp;
 	leaf = bp->b_addr;
+	highstale = 0;
+	lowstale = 0;
 	dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
 	ents = dp->d_ops->leaf_ents_p(leaf);
 
