md/raid1: handle activation of replacement device when recovery completes.

When recovery completes ->spare_active is called.
This checks if the replacement is ready and if so it fails
the original.

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

1 files changed, 33 insertions, 3 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 3d9aa0c92821..f68075189df8 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1265,6 +1265,25 @@ static int raid1_spare_active(struct mddev *mddev)
          */
         for (i = 0; i < conf->raid_disks; i++) {
                 struct md_rdev *rdev = conf->mirrors[i].rdev;
+                struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
+                if (repl
+                    && repl->recovery_offset == MaxSector
+                    && !test_bit(Faulty, &repl->flags)
+                    && !test_and_set_bit(In_sync, &repl->flags)) {
+                        /* replacement has just become active */
+                        if (!rdev ||
+                            !test_and_clear_bit(In_sync, &rdev->flags))
+                                count++;
+                        if (rdev) {
+                                /* Replaced device not technically
+                                 * faulty, but we need to be sure
+                                 * it gets removed and never re-added
+                                 */
+                                set_bit(Faulty, &rdev->flags);
+                                sysfs_notify_dirent_safe(
+                                        rdev->sysfs_state);
+                        }
+                }
                 if (rdev
                     && !test_bit(Faulty, &rdev->flags)
                     && !test_and_set_bit(In_sync, &rdev->flags)) {
@@ -1362,10 +1381,21 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
                         err = -EBUSY;
                         p->rdev = rdev;
                         goto abort;
-                } else {
-                        clear_bit(Replacement, &rdev->flags);
+                } else if (conf->mirrors[conf->raid_disks + number].rdev) {
+                        /* We just removed a device that is being replaced.
+                         * Move down the replacement.  We drain all IO before
+                         * doing this to avoid confusion.
+                         */
+                        struct md_rdev *repl =
+                                conf->mirrors[conf->raid_disks + number].rdev;
+                        raise_barrier(conf);
+                        clear_bit(Replacement, &repl->flags);
+                        p->rdev = repl;
+                        conf->mirrors[conf->raid_disks + number].rdev = NULL;
+                        lower_barrier(conf);
+                        clear_bit(WantReplacement, &rdev->flags);
+                } else
                         clear_bit(WantReplacement, &rdev->flags);
-                }
                 err = md_integrity_register(mddev);
         }
 abort: