[PATCH] md: make md on-disk bitmaps not host-endian
Current bitmaps use set_bit et.al and so are host-endian, which means
not-portable. Oops.
Define a new version number (4) for which bitmaps are little-endian.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/raid/bitmap.h b/include/linux/raid/bitmap.h
index 9de9919..8994378 100644
--- a/include/linux/raid/bitmap.h
+++ b/include/linux/raid/bitmap.h
@@ -6,7 +6,13 @@
#ifndef BITMAP_H
#define BITMAP_H 1
-#define BITMAP_MAJOR 3
+#define BITMAP_MAJOR_LO 3
+/* version 4 insists the bitmap is in little-endian order
+ * with version 3, it is host-endian which is non-portable
+ */
+#define BITMAP_MAJOR_HI 4
+#define BITMAP_MAJOR_HOSTENDIAN 3
+
#define BITMAP_MINOR 39
/*
@@ -133,7 +139,8 @@
/* use these for bitmap->flags and bitmap->sb->state bit-fields */
enum bitmap_state {
BITMAP_ACTIVE = 0x001, /* the bitmap is in use */
- BITMAP_STALE = 0x002 /* the bitmap file is out of date or had -EIO */
+ BITMAP_STALE = 0x002, /* the bitmap file is out of date or had -EIO */
+ BITMAP_HOSTENDIAN = 0x8000,
};
/* the superblock at the front of the bitmap file -- little endian */