md/raid1: recognise replacements when assembling arrays.

If a Replacement is seen, file it as such.

If we see two replacements (or two normal devices) for the one slot,
abort.

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

1 files changed, 23 insertions, 2 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index f68075189df8..6df0c41578af 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2453,14 +2453,20 @@ static struct r1conf *setup_conf(struct mddev *mddev)
 
         conf->poolinfo->mddev = mddev;
 
+        err = -EINVAL;
         spin_lock_init(&conf->device_lock);
         list_for_each_entry(rdev, &mddev->disks, same_set) {
                 int disk_idx = rdev->raid_disk;
                 if (disk_idx >= mddev->raid_disks
                     || disk_idx < 0)
                         continue;
-                disk = conf->mirrors + disk_idx;
+                if (test_bit(Replacement, &rdev->flags))
+                        disk = conf->mirrors + conf->raid_disks + disk_idx;
+                else
+                        disk = conf->mirrors + disk_idx;
 
+                if (disk->rdev)
+                        goto abort;
                 disk->rdev = rdev;
 
                 disk->head_position = 0;
@@ -2476,11 +2482,27 @@ static struct r1conf *setup_conf(struct mddev *mddev)
         conf->pending_count = 0;
         conf->recovery_disabled = mddev->recovery_disabled - 1;
 
+        err = -EIO;
         conf->last_used = -1;
         for (i = 0; i < conf->raid_disks * 2; i++) {
 
                 disk = conf->mirrors + i;
 
+                if (i < conf->raid_disks &&
+                    disk[conf->raid_disks].rdev) {
+                        /* This slot has a replacement. */
+                        if (!disk->rdev) {
+                                /* No original, just make the replacement
+                                 * a recovering spare
+                                 */
+                                disk->rdev =
+                                        disk[conf->raid_disks].rdev;
+                                disk[conf->raid_disks].rdev = NULL;
+                        } else if (!test_bit(In_sync, &disk->rdev->flags))
+                                /* Original is not in_sync - bad */
+                                goto abort;
+                }
+
                 if (!disk->rdev ||
                     !test_bit(In_sync, &disk->rdev->flags)) {
                         disk->head_position = 0;
@@ -2494,7 +2516,6 @@ static struct r1conf *setup_conf(struct mddev *mddev)
                         conf->last_used = i;
         }
 
-        err = -EIO;
         if (conf->last_used < 0) {
                 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
                        mdname(mddev));