md: separate meta and data devs
Allow the metadata to be on a separate device from the
data.
This doesn't mean the data and metadata will by on separate
physical devices - it simply gives device-mapper and userspace
tools more flexibility.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 1977765..6cf5871 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -264,14 +264,18 @@
static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
{
mdk_rdev_t *rdev = NULL;
+ struct block_device *bdev;
mddev_t *mddev = bitmap->mddev;
while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
int size = PAGE_SIZE;
loff_t offset = mddev->bitmap_info.offset;
+
+ bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
+
if (page->index == bitmap->file_pages-1)
size = roundup(bitmap->last_page_size,
- bdev_logical_block_size(rdev->bdev));
+ bdev_logical_block_size(bdev));
/* Just make sure we aren't corrupting data or
* metadata
*/
