Add --data-offset flag for Create and Grow

This can be used to over-ride the automatic assignment of
data offset.
For --create, it is useful to re-create old arrays where different
   defaults applied.
For --grow it may be able to force a reshape in the reverse direction.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 4 insertions, 1 deletions

diff --git a/mdadm.h b/mdadm.h
index 425cac39..79c47be4 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -326,6 +326,7 @@ enum special_options {
 	OffRootOpt,
 	Prefer,
 	KillOpt,
+	DataOffset,
 };
 
 enum prefix_standard {
@@ -1099,6 +1100,7 @@ extern int Grow_addbitmap(char *devname, int fd,
 			  struct context *c, struct shape *s);
 extern int Grow_reshape(char *devname, int fd,
 			struct mddev_dev *devlist,
+			unsigned long long data_offset,
 			struct context *c, struct shape *s);
 extern int Grow_restart(struct supertype *st, struct mdinfo *info,
 			int *fdlist, int cnt, char *backup_file, int verbose);
@@ -1127,7 +1129,8 @@ extern int Create(struct supertype *st, char *mddev,
 		  char *name, int *uuid,
 		  int subdevs, struct mddev_dev *devlist,
 		  struct shape *s,
-		  struct context *c);
+		  struct context *c,
+		  unsigned long long data_offset);
 
 extern int Detail(char *dev, struct context *c);
 extern int Detail_Platform(struct superswitch *ss, int scan, int verbose, int export, char *controller_path);