md/raid5: minor code cleanups in make_request.

... and to be certain the that make_request doesn't wait forever,
add a 'wake_up' when ->reshape_progress has been set to MaxSector

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

1 files changed, 7 insertions, 9 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index fb11c13eb69c..bb4b12e370df 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3637,10 +3637,9 @@ static int make_request(struct request_queue *q, struct bio * bi)
 
         retry:
                 previous = 0;
+                disks = conf->raid_disks;
                 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
-                if (likely(conf->reshape_progress == MaxSector))
-                        disks = conf->raid_disks;
-                else {
+                if (unlikely(conf->reshape_progress != MaxSector)) {
                         /* spinlock is needed as reshape_progress may be
                          * 64bit on a 32bit platform, and so it might be
                          * possible to see a half-updated value
@@ -3650,7 +3649,6 @@ static int make_request(struct request_queue *q, struct bio * bi)
                          * to check again.
                          */
                         spin_lock_irq(&conf->device_lock);
-                        disks = conf->raid_disks;
                         if (mddev->delta_disks < 0
                             ? logical_sector < conf->reshape_progress
                             : logical_sector >= conf->reshape_progress) {
@@ -3679,7 +3677,7 @@ static int make_request(struct request_queue *q, struct bio * bi)
                 sh = get_active_stripe(conf, new_sector, previous,
                                        (bi->bi_rw&RWA_MASK));
                 if (sh) {
-                        if (unlikely(conf->reshape_progress != MaxSector)) {
+                        if (unlikely(previous)) {
                                 /* expansion might have moved on while waiting for a
                                  * stripe, so we must do the range check again.
                                  * Expansion could still move past after this
@@ -3690,10 +3688,9 @@ static int make_request(struct request_queue *q, struct bio * bi)
                                  */
                                 int must_retry = 0;
                                 spin_lock_irq(&conf->device_lock);
-                                if ((mddev->delta_disks < 0
-                                     ? logical_sector >= conf->reshape_progress
-                                     : logical_sector < conf->reshape_progress)
-                                    && previous)
+                                if (mddev->delta_disks < 0
+                                    ? logical_sector >= conf->reshape_progress
+                                    : logical_sector < conf->reshape_progress)
                                         /* mismatch, need to try again */
                                         must_retry = 1;
                                 spin_unlock_irq(&conf->device_lock);
@@ -4977,6 +4974,7 @@ static void end_reshape(raid5_conf_t *conf)
                 conf->previous_raid_disks = conf->raid_disks;
                 conf->reshape_progress = MaxSector;
                 spin_unlock_irq(&conf->device_lock);
+                wake_up(&conf->wait_for_overlap);
 
                 /* read-ahead size must cover two whole stripes, which is
                  * 2 * (datadisks) * chunksize where 'n' is the number of raid devices