md/raid5: Check all disks in a stripe_head for reshape progress

When testing if a previous stripe has had reshape expand past it, use
the earliest or latest logical sector in all the disks for that stripe
head. This will allow adding multiple disks at a time in a subesquent
patch.

To do this cleaner, refactor the check into a helper function called
stripe_ahead_of_reshape().

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index f243043..ca91cbe 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5819,6 +5819,40 @@ static bool ahead_of_reshape(struct mddev *mddev, sector_t sector,
                                          sector >= reshape_sector;
 }
 
+static bool range_ahead_of_reshape(struct mddev *mddev, sector_t min,
+                                  sector_t max, sector_t reshape_sector)
+{
+       return mddev->reshape_backwards ? max < reshape_sector :
+                                         min >= reshape_sector;
+}
+
+static bool stripe_ahead_of_reshape(struct mddev *mddev, struct r5conf *conf,
+                                   struct stripe_head *sh)
+{
+       sector_t max_sector = 0, min_sector = MaxSector;
+       bool ret = false;
+       int dd_idx;
+
+       for (dd_idx = 0; dd_idx < sh->disks; dd_idx++) {
+               if (dd_idx == sh->pd_idx)
+                       continue;
+
+               min_sector = min(min_sector, sh->dev[dd_idx].sector);
+               max_sector = min(max_sector, sh->dev[dd_idx].sector);
+       }
+
+       spin_lock_irq(&conf->device_lock);
+
+       if (!range_ahead_of_reshape(mddev, min_sector, max_sector,
+                                    conf->reshape_progress))
+               /* mismatch, need to try again */
+               ret = true;
+
+       spin_unlock_irq(&conf->device_lock);
+
+       return ret;
+}
+
 enum stripe_result {
        STRIPE_SUCCESS = 0,
        STRIPE_RETRY,
@@ -5883,27 +5917,18 @@ static enum stripe_result make_stripe_request(struct mddev *mddev,
                return STRIPE_FAIL;
        }
 
-       if (unlikely(previous)) {
+       if (unlikely(previous) &&
+           stripe_ahead_of_reshape(mddev, conf, sh)) {
                /*
-                * Expansion might have moved on while waiting for a
-                * stripe, so we must do the range check again.
+                * Expansion moved on while waiting for a stripe.
                 * Expansion could still move past after this
                 * test, but as we are holding a reference to
                 * 'sh', we know that if that happens,
                 *  STRIPE_EXPANDING will get set and the expansion
                 * won't proceed until we finish with the stripe.
                 */
-               int must_retry = 0;
-               spin_lock_irq(&conf->device_lock);
-               if (!ahead_of_reshape(mddev, logical_sector,
-                                     conf->reshape_progress))
-                       /* mismatch, need to try again */
-                       must_retry = 1;
-               spin_unlock_irq(&conf->device_lock);
-               if (must_retry) {
-                       ret = STRIPE_SCHEDULE_AND_RETRY;
-                       goto out_release;
-               }
+               ret = STRIPE_SCHEDULE_AND_RETRY;
+               goto out_release;
        }
 
        if (read_seqcount_retry(&conf->gen_lock, seq)) {