[PATCH] md: allow md intent bitmap to be stored near the superblock.

This provides an alternate to storing the bitmap in a separate file.  The
bitmap can be stored at a given offset from the superblock.  Obviously the
creator of the array must make sure this doesn't intersect with data....
After is good for version-0.90 superblocks.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/include/linux/raid/md.h b/include/linux/raid/md.h
index 75f41d8faed2..ffa316ce4dc8 100644
--- a/include/linux/raid/md.h
+++ b/include/linux/raid/md.h
@@ -60,7 +60,14 @@
  */
 #define MD_MAJOR_VERSION                0
 #define MD_MINOR_VERSION                90
-#define MD_PATCHLEVEL_VERSION           1
+/*
+ * MD_PATCHLEVEL_VERSION indicates kernel functionality.
+ * >=1 means different superblock formats are selectable using SET_ARRAY_INFO
+ *     and major_version/minor_version accordingly
+ * >=2 means that Internal bitmaps are supported by setting MD_SB_BITMAP_PRESENT
+ *     in the super status byte
+ */
+#define MD_PATCHLEVEL_VERSION           2
 
 extern int register_md_personality (int p_num, mdk_personality_t *p);
 extern int unregister_md_personality (int p_num);
@@ -78,6 +85,12 @@ extern void md_unplug_mddev(mddev_t *mddev);
 
 extern void md_print_devices (void);
 
+extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
+                           sector_t sector, int size, struct page *page);
+extern int sync_page_io(struct block_device *bdev, sector_t sector, int size,
+                        struct page *page, int rw);
+
+
 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
 
 #endif