md/raid5: reshape using largest of old and new chunk size
This ensures that even when old and new stripes are overlapping,
we will try to read all of the old before having to write any
of the new.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 80ec9a6..f7fb2b8 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3738,6 +3738,7 @@
int dd_idx;
sector_t writepos, safepos, gap;
sector_t stripe_addr;
+ int reshape_sectors;
if (sector_nr == 0) {
/* If restarting in the middle, skip the initial sectors */
@@ -3755,6 +3756,15 @@
}
}
+ /* We need to process a full chunk at a time.
+ * If old and new chunk sizes differ, we need to process the
+ * largest of these
+ */
+ if (mddev->new_chunk > mddev->chunk_size)
+ reshape_sectors = mddev->new_chunk / 512;
+ else
+ reshape_sectors = mddev->chunk_size / 512;
+
/* we update the metadata when there is more than 3Meg
* in the block range (that is rather arbitrary, should
* probably be time based) or when the data about to be
@@ -3768,12 +3778,12 @@
safepos = conf->reshape_safe;
sector_div(safepos, data_disks);
if (mddev->delta_disks < 0) {
- writepos -= conf->chunk_size/512;
- safepos += conf->chunk_size/512;
+ writepos -= reshape_sectors;
+ safepos += reshape_sectors;
gap = conf->reshape_safe - conf->reshape_progress;
} else {
- writepos += conf->chunk_size/512;
- safepos -= conf->chunk_size/512;
+ writepos += reshape_sectors;
+ safepos -= reshape_sectors;
gap = conf->reshape_progress - conf->reshape_safe;
}
@@ -3799,14 +3809,14 @@
BUG_ON(conf->reshape_progress == 0);
stripe_addr = writepos;
BUG_ON((mddev->dev_sectors &
- ~((sector_t)conf->chunk_size / 512 - 1))
- - (conf->chunk_size / 512) - stripe_addr
+ ~((sector_t)reshape_sectors - 1))
+ - reshape_sectors - stripe_addr
!= sector_nr);
} else {
- BUG_ON(writepos != sector_nr + conf->chunk_size / 512);
+ BUG_ON(writepos != sector_nr + reshape_sectors);
stripe_addr = sector_nr;
}
- for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) {
+ for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
int j;
int skipped = 0;
sh = get_active_stripe(conf, stripe_addr+i, 0, 0);
@@ -3839,9 +3849,9 @@
}
spin_lock_irq(&conf->device_lock);
if (mddev->delta_disks < 0)
- conf->reshape_progress -= i * new_data_disks;
+ conf->reshape_progress -= reshape_sectors * new_data_disks;
else
- conf->reshape_progress += i * new_data_disks;
+ conf->reshape_progress += reshape_sectors * new_data_disks;
spin_unlock_irq(&conf->device_lock);
/* Ok, those stripe are ready. We can start scheduling
* reads on the source stripes.
@@ -3867,7 +3877,7 @@
/* If this takes us to the resync_max point where we have to pause,
* then we need to write out the superblock.
*/
- sector_nr += conf->chunk_size>>9;
+ sector_nr += reshape_sectors;
if (sector_nr >= mddev->resync_max) {
/* Cannot proceed until we've updated the superblock... */
wait_event(conf->wait_for_overlap,
@@ -3883,7 +3893,7 @@
spin_unlock_irq(&conf->device_lock);
wake_up(&conf->wait_for_overlap);
}
- return conf->chunk_size>>9;
+ return reshape_sectors;
}
/* FIXME go_faster isn't used */