md: add explicit method to signal the end of a reshape.

Currently raid5 (the only module that supports restriping)
notices that the reshape has finished be sync_request being
given a large value, and handles any cleanup them.

This patch changes it so md_check_recovery calls into an
explicit finish_reshape method as well.

The clean-up from sync_request can do things that need to be
done promptly, typically things local to the raid5_conf_t
structure.

The "finish_reshape" method is called under the mddev_lock
so it can do things involving reconfiguring the device.

This allows us to get rid of md_set_array_sectors_locked, which
would have caused a deadlock if you tried to stop and array
while a reshape was happening.

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

1 files changed, 3 insertions, 8 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 923d1250b9a9..c50931352b23 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5073,14 +5073,6 @@ void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors)
 }
 EXPORT_SYMBOL(md_set_array_sectors);
 
-void md_set_array_sectors_lock(mddev_t *mddev, sector_t array_sectors)
-{
-        mddev_lock(mddev);
-        md_set_array_sectors(mddev, array_sectors);
-        mddev_unlock(mddev);
-}
-EXPORT_SYMBOL(md_set_array_sectors_lock);
-
 static int update_size(mddev_t *mddev, sector_t num_sectors)
 {
         mdk_rdev_t *rdev;
@@ -6641,6 +6633,9 @@ void md_check_recovery(mddev_t *mddev)
                                         sysfs_notify(&mddev->kobj, NULL,
                                                      "degraded");
                         }
+                        if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
+                            mddev->pers->finish_reshape)
+                                mddev->pers->finish_reshape(mddev);
                         md_update_sb(mddev, 1);
 
                         /* if array is no-longer degraded, then any saved_raid_disk