md: add 'size' as a personality method
In preparation for giving userspace control over ->array_sectors we need
to be able to retrieve the 'default' size, and the 'anticipated' size
when a reshape is requested. For personalities that do not reshape emit
a warning if anything but the default size is requested.
In the raid5 case we need to update ->previous_raid_disks to make the
new 'default' size available.
Reviewed-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index d5d99290..b6bb976 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -101,6 +101,16 @@
return ret;
}
+static sector_t linear_size(mddev_t *mddev, sector_t sectors, int raid_disks)
+{
+ linear_conf_t *conf = mddev_to_conf(mddev);
+
+ WARN_ONCE(sectors || raid_disks,
+ "%s does not support generic reshape\n", __func__);
+
+ return conf->array_sectors;
+}
+
static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks)
{
linear_conf_t *conf;
@@ -253,7 +263,7 @@
if (!conf)
return 1;
mddev->private = conf;
- mddev->array_sectors = conf->array_sectors;
+ mddev->array_sectors = linear_size(mddev, 0, 0);
blk_queue_merge_bvec(mddev->queue, linear_mergeable_bvec);
mddev->queue->unplug_fn = linear_unplug;
@@ -287,7 +297,7 @@
newconf->prev = mddev_to_conf(mddev);
mddev->private = newconf;
mddev->raid_disks++;
- mddev->array_sectors = newconf->array_sectors;
+ mddev->array_sectors = linear_size(mddev, 0, 0);
set_capacity(mddev->gendisk, mddev->array_sectors);
return 0;
}
@@ -385,6 +395,7 @@
.stop = linear_stop,
.status = linear_status,
.hot_add_disk = linear_add,
+ .size = linear_size,
};
static int __init linear_init (void)