[PATCH] md: Fix bad interaction between sync checkpointing and recovery

Md devices (raid1/raid5) can resync or recover.
There are similar but importantly different.
resync happens after an unclean shutdown
recovery happens when a failed drive is being replaced by a hot spare.

The sync-checkpoint code confused the two somewhat and this causes
problems.

This patch makes sure "recovery_cp" only relates to resync,
not recovery.
It also fixes a small problem with recording spares in
the superblock.

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5689df88774adb97af94ec2c450a81395d0067ce..8a8dc92a527da038cf3c8a998753c0ea17c8a093 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -713,7 +713,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
        sb->disks[0].state = (1<<MD_DISK_REMOVED);
        ITERATE_RDEV(mddev,rdev2,tmp) {
                mdp_disk_t *d;
-               if (rdev2->raid_disk >= 0)
+               if (rdev2->raid_disk >= 0 && rdev2->in_sync && !rdev2->faulty)
                        rdev2->desc_nr = rdev2->raid_disk;
                else
                        rdev2->desc_nr = next_spare++;
@@ -722,7 +722,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
                d->number = rdev2->desc_nr;
                d->major = MAJOR(rdev2->bdev->bd_dev);
                d->minor = MINOR(rdev2->bdev->bd_dev);
-               if (rdev2->raid_disk >= 0)
+               if (rdev2->raid_disk >= 0 && rdev->in_sync && !rdev2->faulty)
                        d->raid_disk = rdev2->raid_disk;
                else
                        d->raid_disk = rdev2->desc_nr; /* compatibility */
@@ -3020,9 +3020,13 @@ static void md_do_sync(mddev_t *mddev)
               sysctl_speed_limit_max);
 
        is_mddev_idle(mddev); /* this also initializes IO event counters */
+       if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
+               j = mddev->recovery_cp;
+       else
+               j = 0;
        for (m = 0; m < SYNC_MARKS; m++) {
                mark[m] = jiffies;
-               mark_cnt[m] = mddev->recovery_cp;
+               mark_cnt[m] = j;
        }
        last_mark = 0;
        mddev->resync_mark = mark[last_mark];
@@ -3039,10 +3043,10 @@ static void md_do_sync(mddev_t *mddev)
        init_waitqueue_head(&mddev->recovery_wait);
        last_check = 0;
 
-       if (mddev->recovery_cp)
+       if (j)
                printk(KERN_INFO "md: resuming recovery of md%d from checkpoint.\n", mdidx(mddev));
 
-       for (j = mddev->recovery_cp; j < max_sectors;) {
+       while (j < max_sectors) {
                int sectors;
 
                sectors = mddev->pers->sync_request(mddev, j, currspeed < sysctl_speed_limit_min);