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.c b/drivers/md/md.c
index fe04846..5703c2e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2210,7 +2210,7 @@
}
}
-static void md_update_sb(struct mddev *mddev, int force_change)
+void md_update_sb(struct mddev *mddev, int force_change)
{
struct md_rdev *rdev;
int sync_req;
@@ -2371,6 +2371,7 @@
wake_up(&rdev->blocked_wait);
}
}
+EXPORT_SYMBOL(md_update_sb);
/* words written to sysfs files may, or may not, be \n terminated.
* We want to accept with case. For this we use cmd_match.
@@ -3151,7 +3152,7 @@
kick_rdev_from_array(rdev);
continue;
}
- if (rdev != freshest)
+ if (rdev != freshest) {
if (super_types[mddev->major_version].
validate_super(mddev, rdev)) {
printk(KERN_WARNING "md: kicking non-fresh %s"
@@ -3160,6 +3161,15 @@
kick_rdev_from_array(rdev);
continue;
}
+ /* No device should have a Candidate flag
+ * when reading devices
+ */
+ if (test_bit(Candidate, &rdev->flags)) {
+ pr_info("md: kicking Cluster Candidate %s from array!\n",
+ bdevname(rdev->bdev, b));
+ kick_rdev_from_array(rdev);
+ }
+ }
if (mddev->level == LEVEL_MULTIPATH) {
rdev->desc_nr = i++;
rdev->raid_disk = rdev->desc_nr;
@@ -5655,7 +5665,6 @@
info.state |= (1<<MD_SB_BITMAP_PRESENT);
if (mddev_is_clustered(mddev))
info.state |= (1<<MD_SB_CLUSTERED);
-
info.active_disks = insync;
info.working_disks = working;
info.failed_disks = failed;
@@ -5744,6 +5753,13 @@
struct md_rdev *rdev;
dev_t dev = MKDEV(info->major,info->minor);
+ if (mddev_is_clustered(mddev) &&
+ !(info->state & ((1 << MD_DISK_CLUSTER_ADD) | (1 << MD_DISK_CANDIDATE)))) {
+ pr_err("%s: Cannot add to clustered mddev. Try --cluster-add\n",
+ mdname(mddev));
+ return -EINVAL;
+ }
+
if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
return -EOVERFLOW;
@@ -5830,6 +5846,25 @@
else
clear_bit(WriteMostly, &rdev->flags);
+ /*
+ * check whether the device shows up in other nodes
+ */
+ if (mddev_is_clustered(mddev)) {
+ if (info->state & (1 << MD_DISK_CANDIDATE)) {
+ /* Through --cluster-confirm */
+ set_bit(Candidate, &rdev->flags);
+ md_cluster_ops->new_disk_ack(mddev, true);
+ } else if (info->state & (1 << MD_DISK_CLUSTER_ADD)) {
+ /* --add initiated by this node */
+ err = md_cluster_ops->add_new_disk_start(mddev, rdev);
+ if (err) {
+ md_cluster_ops->add_new_disk_finish(mddev);
+ export_rdev(rdev);
+ return err;
+ }
+ }
+ }
+
rdev->raid_disk = -1;
err = bind_rdev_to_array(rdev, mddev);
if (!err && !mddev->pers->hot_remove_disk) {
@@ -5855,6 +5890,9 @@
if (!err)
md_new_event(mddev);
md_wakeup_thread(mddev->thread);
+ if (mddev_is_clustered(mddev) &&
+ (info->state & (1 << MD_DISK_CLUSTER_ADD)))
+ md_cluster_ops->add_new_disk_finish(mddev);
return err;
}
@@ -6456,6 +6494,7 @@
case SET_DISK_FAULTY:
case STOP_ARRAY:
case STOP_ARRAY_RO:
+ case CLUSTERED_DISK_NACK:
return true;
default:
return false;
@@ -6728,6 +6767,13 @@
goto unlock;
}
+ case CLUSTERED_DISK_NACK:
+ if (mddev_is_clustered(mddev))
+ md_cluster_ops->new_disk_ack(mddev, false);
+ else
+ err = -EINVAL;
+ goto unlock;
+
case HOT_ADD_DISK:
err = hot_add_disk(mddev, new_decode_dev(arg));
goto unlock;