Manage: check alignment when stopping an array undergoing reshape.

To be able to revert-reshape of raid4/5/6 which is changing
the number of devices, the reshape must has been stopped on a multiple
of the old and new stripe sizes.

The kernel only enforces the new stripe size multiple.

So we enforce the old-stripe-size multiple by careful use of
"sync_max" and monitoring "reshape_position".

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

1 files changed, 4 insertions, 0 deletions

diff --git a/mdadm.h b/mdadm.h
index 13ea26a0..13aa84ab 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -538,6 +538,9 @@ extern int sysfs_get_fd(struct mdinfo *sra, struct mdinfo *dev,
 extern int sysfs_fd_get_ll(int fd, unsigned long long *val);
 extern int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
 			char *name, unsigned long long *val);
+extern int sysfs_fd_get_two(int fd, unsigned long long *v1, unsigned long long *v2);
+extern int sysfs_get_two(struct mdinfo *sra, struct mdinfo *dev,
+			 char *name, unsigned long long *v1, unsigned long long *v2);
 extern int sysfs_fd_get_str(int fd, char *val, int size);
 extern int sysfs_attribute_available(struct mdinfo *sra, struct mdinfo *dev,
 				     char *name);
@@ -1277,6 +1280,7 @@ extern char *conf_word(FILE *file, int allow_key);
 extern void print_quoted(char *str);
 extern void print_escape(char *str);
 extern int use_udev(void);
+extern unsigned long GCD(unsigned long a, unsigned long b);
 extern int conf_name_is_free(char *name);
 extern int conf_verify_devnames(struct mddev_ident *array_list);
 extern int devname_matches(char *name, char *match);