Merge branch 'core-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[pandora-kernel.git] / drivers / md / raid5.c

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 2b521ee..b8a2c5d 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3785,7 +3785,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped
                    conf->reshape_progress < raid5_size(mddev, 0, 0)) {
                        sector_nr = raid5_size(mddev, 0, 0)
                                - conf->reshape_progress;
-               } else if (mddev->delta_disks > 0 &&
+               } else if (mddev->delta_disks >= 0 &&
                           conf->reshape_progress > 0)
                        sector_nr = conf->reshape_progress;
                sector_div(sector_nr, new_data_disks);
@@ -4509,7 +4509,26 @@ static int run(mddev_t *mddev)
                           (old_disks-max_degraded));
                /* here_old is the first stripe that we might need to read
                 * from */
-               if (here_new >= here_old) {
+               if (mddev->delta_disks == 0) {
+                       /* We cannot be sure it is safe to start an in-place
+                        * reshape.  It is only safe if user-space if monitoring
+                        * and taking constant backups.
+                        * mdadm always starts a situation like this in
+                        * readonly mode so it can take control before
+                        * allowing any writes.  So just check for that.
+                        */
+                       if ((here_new * mddev->new_chunk_sectors != 
+                            here_old * mddev->chunk_sectors) ||
+                           mddev->ro == 0) {
+                               printk(KERN_ERR "raid5: in-place reshape must be started"
+                                      " in read-only mode - aborting\n");
+                               return -EINVAL;
+                       }
+               } else if (mddev->delta_disks < 0
+                   ? (here_new * mddev->new_chunk_sectors <=
+                      here_old * mddev->chunk_sectors)
+                   : (here_new * mddev->new_chunk_sectors >=
+                      here_old * mddev->chunk_sectors)) {
                        /* Reading from the same stripe as writing to - bad */
                        printk(KERN_ERR "raid5: reshape_position too early for "
                               "auto-recovery - aborting.\n");
@@ -5078,8 +5097,15 @@ static void raid5_finish_reshape(mddev_t *mddev)
                                        mddev->degraded--;
                        for (d = conf->raid_disks ;
                             d < conf->raid_disks - mddev->delta_disks;
-                            d++)
-                               raid5_remove_disk(mddev, d);
+                            d++) {
+                               mdk_rdev_t *rdev = conf->disks[d].rdev;
+                               if (rdev && raid5_remove_disk(mddev, d) == 0) {
+                                       char nm[20];
+                                       sprintf(nm, "rd%d", rdev->raid_disk);
+                                       sysfs_remove_link(&mddev->kobj, nm);
+                                       rdev->raid_disk = -1;
+                               }
+                       }
                }
                mddev->layout = conf->algorithm;
                mddev->chunk_sectors = conf->chunk_sectors;