[PATCH] MD - when writing superblock, generate from mddev/rdev info.

when writing superblock, generate from mddev/rdev info.

Rather than relying on the superblock info being kept up-to-date,
we regenerate the superblock from mddev/rdev info before
each write.

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 98544cd02a8b58354e30da6ceb265c800ce443b0..aeea2b334eaab1bbf57a4d8e963632c948e8caeb 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -860,44 +860,73 @@ fail:
        return 1;
 }
 
-static void set_this_disk(mddev_t *mddev, mdk_rdev_t *rdev)
-{
-       int i, ok = 0;
-       mdp_disk_t *desc;
-
-       for (i = 0; i < MD_SB_DISKS; i++) {
-               desc = mddev->sb->disks + i;
-#if 0
-               if (disk_faulty(desc)) {
-                       if (mk_kdev(desc->major,desc->minor) == rdev->dev)
-                               ok = 1;
-                       continue;
-               }
-#endif
-               if (kdev_same(mk_kdev(desc->major,desc->minor), rdev->dev)) {
-                       rdev->sb->this_disk = *desc;
-                       ok = 1;
-                       break;
-               }
-       }
-
-       if (!ok) {
-               MD_BUG();
-       }
-}
-
 static int sync_sbs(mddev_t * mddev)
 {
        mdk_rdev_t *rdev;
        mdp_super_t *sb;
        struct list_head *tmp;
 
+       /* make sb->disks match mddev->disks 
+        * 1/ zero out disks
+        * 2/ Add info for each disk, keeping track of highest desc_nr
+        * 3/ any empty disks < highest become removed
+        *
+        * disks[0] gets initialised to REMOVED because
+        * we cannot be sure from other fields if it has
+        * been initialised or not.
+        */
+       int highest = 0;
+       int i;
+       int active=0, working=0,failed=0,spare=0,nr_disks=0;
+
+       sb = mddev->sb;
+
+       sb->disks[0].state = (1<<MD_DISK_REMOVED);
+       ITERATE_RDEV(mddev,rdev,tmp) {
+               mdp_disk_t *d = &sb->disks[rdev->desc_nr];
+               nr_disks++;
+               d->number = rdev->desc_nr;
+               d->major = major(rdev->dev);
+               d->minor = minor(rdev->dev);
+               d->raid_disk = rdev->raid_disk;
+               if (rdev->faulty) {
+                       d->state = (1<<MD_DISK_FAULTY);
+                       failed++;
+               } else if (rdev->in_sync) {
+                       d->state = (1<<MD_DISK_ACTIVE);
+                       d->state |= (1<<MD_DISK_SYNC);
+                       active++;
+                       working++;
+               } else {
+                       d->state = 0;
+                       spare++;
+                       working++;
+               }
+               if (rdev->desc_nr > highest)
+                       highest = rdev->desc_nr;
+       }
+       
+       /* now set the "removed" bit on any non-trailing holes */
+       for (i=0; i<highest; i++) {
+               mdp_disk_t *d = &sb->disks[i];
+               if (d->state == 0 && d->number == 0) {
+                       d->number = i;
+                       d->raid_disk = i;
+                       d->state = (1<<MD_DISK_REMOVED);
+               }
+       }
+       sb->nr_disks = nr_disks;
+       sb->active_disks = active;
+       sb->working_disks = working;
+       sb->failed_disks = failed;
+       sb->spare_disks = spare;
+
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (rdev->faulty || rdev->alias_device)
                        continue;
                sb = rdev->sb;
                *sb = *mddev->sb;
-               set_this_disk(mddev, rdev);
+               sb->this_disk = sb->disks[rdev->desc_nr];
                sb->sb_csum = calc_sb_csum(sb);
        }
        return 0;