Add new disk to clustered array
Algorithm:
1. Node 1 issues mdadm --manage /dev/mdX --add /dev/sdYY which issues
ioctl(ADD_NEW_DISC with disc.state set to MD_DISK_CLUSTER_ADD)
2. Node 1 sends NEWDISK with uuid and slot number
3. Other nodes issue kobject_uevent_env with uuid and slot number
(Steps 4,5 could be a udev rule)
4. In userspace, the node searches for the disk, perhaps
using blkid -t SUB_UUID=""
5. Other nodes issue either of the following depending on whether the disk
was found:
ioctl(ADD_NEW_DISK with disc.state set to MD_DISK_CANDIDATE and
disc.number set to slot number)
ioctl(CLUSTERED_DISK_NACK)
6. Other nodes drop lock on no-new-devs (CR) if device is found
7. Node 1 attempts EX lock on no-new-devs
8. If node 1 gets the lock, it sends METADATA_UPDATED after unmarking the disk
as SpareLocal
9. If not (get no-new-dev lock), it fails the operation and sends METADATA_UPDATED
10. Other nodes understand if the device is added or not by reading the superblock again after receiving the METADATA_UPDATED message.
Signed-off-by: Lidong Zhong <lzhong@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
diff --git a/drivers/md/md-cluster.h b/drivers/md/md-cluster.h
index 0378540..60d7e58 100644
--- a/drivers/md/md-cluster.h
+++ b/drivers/md/md-cluster.h
@@ -6,6 +6,7 @@
#include "md.h"
struct mddev;
+struct md_rdev;
struct md_cluster_operations {
int (*join)(struct mddev *mddev, int nodes);
@@ -18,6 +19,9 @@
int (*metadata_update_finish)(struct mddev *mddev);
int (*metadata_update_cancel)(struct mddev *mddev);
int (*area_resyncing)(struct mddev *mddev, sector_t lo, sector_t hi);
+ int (*add_new_disk_start)(struct mddev *mddev, struct md_rdev *rdev);
+ int (*add_new_disk_finish)(struct mddev *mddev);
+ void (*new_disk_ack)(struct mddev *mddev, bool ack);
};
#endif /* _MD_CLUSTER_H */