linux/drivers/md/md-cluster.h
Guoqing Jiang 818da59f97 md-cluster: add the support for resize
To update size for cluster raid, we need to make
sure all nodes can perform the change successfully.
However, it is possible that some of them can't do
it due to failure (bitmap_resize could fail). So
we need to consider the issue before we set the
capacity unconditionally, and we use below steps
to perform sanity check.

1. A change the size, then broadcast METADATA_UPDATED
   msg.
2. B and C receive METADATA_UPDATED change the size
   excepts call set_capacity, sync_size is not update
   if the change failed. Also call bitmap_update_sb
   to sync sb to disk.
3. A checks other node's sync_size, if sync_size has
   been updated in all nodes, then send CHANGE_CAPACITY
   msg otherwise send msg to revert previous change.
4. B and C call set_capacity if receive CHANGE_CAPACITY
   msg, otherwise pers->resize will be called to restore
   the old value.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-16 16:55:50 -07:00

34 lines
1.2 KiB
C

#ifndef _MD_CLUSTER_H
#define _MD_CLUSTER_H
#include "md.h"
struct mddev;
struct md_rdev;
struct md_cluster_operations {
int (*join)(struct mddev *mddev, int nodes);
int (*leave)(struct mddev *mddev);
int (*slot_number)(struct mddev *mddev);
int (*resync_info_update)(struct mddev *mddev, sector_t lo, sector_t hi);
int (*metadata_update_start)(struct mddev *mddev);
int (*metadata_update_finish)(struct mddev *mddev);
void (*metadata_update_cancel)(struct mddev *mddev);
int (*resync_start)(struct mddev *mddev);
int (*resync_finish)(struct mddev *mddev);
int (*area_resyncing)(struct mddev *mddev, int direction, sector_t lo, sector_t hi);
int (*add_new_disk)(struct mddev *mddev, struct md_rdev *rdev);
void (*add_new_disk_cancel)(struct mddev *mddev);
int (*new_disk_ack)(struct mddev *mddev, bool ack);
int (*remove_disk)(struct mddev *mddev, struct md_rdev *rdev);
void (*load_bitmaps)(struct mddev *mddev, int total_slots);
int (*gather_bitmaps)(struct md_rdev *rdev);
int (*lock_all_bitmaps)(struct mddev *mddev);
void (*unlock_all_bitmaps)(struct mddev *mddev);
void (*update_size)(struct mddev *mddev, sector_t old_dev_sectors);
};
#endif /* _MD_CLUSTER_H */