md: Support write-intent bitmaps with externally managed metadata.
In this case, the metadata needs to not be in the same
sector as the bitmap.
md will not read/write any bitmap metadata. Config must be
done via sysfs and when a recovery makes the array non-degraded
again, writing 'true' to 'bitmap/can_clear' will allow bits in
the bitmap to be cleared again.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/md.h b/drivers/md/md.h
index fce0207..d913888 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -296,6 +296,7 @@
unsigned long chunksize;
unsigned long daemon_sleep; /* how many seconds between updates? */
unsigned long max_write_behind; /* write-behind mode */
+ int external;
} bitmap_info;
struct list_head all_mddevs;