md/raid5: recognise replacements when assembling array.

If a Replacement is seen, file it as such.

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

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index b443cd2..c80f8c2 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -4847,7 +4847,15 @@ static struct r5conf *setup_conf(struct mddev *mddev)
                        continue;
                disk = conf->disks + raid_disk;
 
-               disk->rdev = rdev;
+               if (test_bit(Replacement, &rdev->flags)) {
+                       if (disk->replacement)
+                               goto abort;
+                       disk->replacement = rdev;
+               } else {
+                       if (disk->rdev)
+                               goto abort;
+                       disk->rdev = rdev;
+               }
 
                if (test_bit(In_sync, &rdev->flags)) {
                        char b[BDEVNAME_SIZE];
@@ -4936,6 +4944,7 @@ static int run(struct mddev *mddev)
        int dirty_parity_disks = 0;
        struct md_rdev *rdev;
        sector_t reshape_offset = 0;
+       int i;
 
        if (mddev->recovery_cp != MaxSector)
                printk(KERN_NOTICE "md/raid:%s: not clean"
@@ -5025,12 +5034,25 @@ static int run(struct mddev *mddev)
        conf->thread = NULL;
        mddev->private = conf;
 
-       /*
-        * 0 for a fully functional array, 1 or 2 for a degraded array.
-        */
-       list_for_each_entry(rdev, &mddev->disks, same_set) {
-               if (rdev->raid_disk < 0)
+       for (i = 0; i < conf->raid_disks && conf->previous_raid_disks;
+            i++) {
+               rdev = conf->disks[i].rdev;
+               if (!rdev && conf->disks[i].replacement) {
+                       /* The replacement is all we have yet */
+                       rdev = conf->disks[i].replacement;
+                       conf->disks[i].replacement = NULL;
+                       clear_bit(Replacement, &rdev->flags);
+                       conf->disks[i].rdev = rdev;
+               }
+               if (!rdev)
                        continue;
+               if (conf->disks[i].replacement &&
+                   conf->reshape_progress != MaxSector) {
+                       /* replacements and reshape simply do not mix. */
+                       printk(KERN_ERR "md: cannot handle concurrent "
+                              "replacement and reshape.\n");
+                       goto abort;
+               }
                if (test_bit(In_sync, &rdev->flags)) {
                        working_disks++;
                        continue;
@@ -5064,6 +5086,9 @@ static int run(struct mddev *mddev)
                dirty_parity_disks++;
        }
 
+       /*
+        * 0 for a fully functional array, 1 or 2 for a degraded array.
+        */
        mddev->degraded = calc_degraded(conf);
 
        if (has_failed(conf)) {