reiserfs: add comment to explain endianness issue in xattr_hash

[sfrench/cifs-2.6.git] / fs / reiserfs / xattr.c

diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 32d8986c26fb1fa2d3c5140d9fb7629eaf9b865f..b5b26d8a192c4ae71d5a958bd4968183f3ca010a 100644 (file)
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -450,6 +450,15 @@ fail:
 
 static inline __u32 xattr_hash(const char *msg, int len)
 {
+       /*
+        * csum_partial() gives different results for little-endian and
+        * big endian hosts. Images created on little-endian hosts and
+        * mounted on big-endian hosts(and vice versa) will see csum mismatches
+        * when trying to fetch xattrs. Treating the hash as __wsum_t would
+        * lower the frequency of mismatch.  This is an endianness bug in
+        * reiserfs.  The return statement would result in a sparse warning. Do
+        * not fix the sparse warning so as to not hide a reminder of the bug.
+        */
        return csum_partial(msg, len, 0);
 }