From 1aee41f637694d4bbf91c24195f2b63e3f6badd2 Mon Sep 17 00:00:00 2001 From: Goldwyn Rodrigues Date: Wed, 29 Oct 2014 18:51:31 -0500 Subject: 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 Signed-off-by: Goldwyn Rodrigues --- drivers/md/md.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/md/md.h') diff --git a/drivers/md/md.h b/drivers/md/md.h index bfebcfdf54e6..6dc0ce09f50c 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -171,6 +171,10 @@ enum flag_bits { * a want_replacement device with same * raid_disk number. */ + Candidate, /* For clustered environments only: + * This device is seen locally but not + * by the whole cluster + */ }; #define BB_LEN_MASK (0x00000000000001FFULL) @@ -666,6 +670,7 @@ extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs, extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule); extern void md_reload_sb(struct mddev *mddev); +extern void md_update_sb(struct mddev *mddev, int force); static inline int mddev_check_plugged(struct mddev *mddev) { return !!blk_check_plugged(md_unplug, mddev, -- cgit v1.2.3