1 files changed, 43 insertions, 36 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index c5439dce0295..a4502686e7a8 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2774,10 +2774,12 @@ static void handle_stripe_clean_event(struct r5conf *conf,
                         dev = &sh->dev[i];
                         if (!test_bit(R5_LOCKED, &dev->flags) &&
                             (test_bit(R5_UPTODATE, &dev->flags) ||
-                             test_and_clear_bit(R5_Discard, &dev->flags))) {
+                             test_bit(R5_Discard, &dev->flags))) {
                                 /* We can return any write requests */
                                 struct bio *wbi, *wbi2;
                                 pr_debug("Return write for disc %d\n", i);
+                                if (test_and_clear_bit(R5_Discard, &dev->flags))
+                                        clear_bit(R5_UPTODATE, &dev->flags);
                                 wbi = dev->written;
                                 dev->written = NULL;
                                 while (wbi && wbi->bi_sector <
@@ -2795,7 +2797,8 @@ static void handle_stripe_clean_event(struct r5conf *conf,
                                          !test_bit(STRIPE_DEGRADED, &sh->state),
                                                 0);
                         }
-                }
+                } else if (test_bit(R5_Discard, &sh->dev[i].flags))
+                        clear_bit(R5_Discard, &sh->dev[i].flags);
 
         if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
                 if (atomic_dec_and_test(&conf->pending_full_writes))
@@ -3490,40 +3493,6 @@ static void handle_stripe(struct stripe_head *sh)
                         handle_failed_sync(conf, sh, &s);
         }
 
-        /*
-         * might be able to return some write requests if the parity blocks
-         * are safe, or on a failed drive
-         */
-        pdev = &sh->dev[sh->pd_idx];
-        s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
-                || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
-        qdev = &sh->dev[sh->qd_idx];
-        s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
-                || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
-                || conf->level < 6;
-
-        if (s.written &&
-            (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
-                             && !test_bit(R5_LOCKED, &pdev->flags)
-                             && (test_bit(R5_UPTODATE, &pdev->flags) ||
-                                 test_bit(R5_Discard, &pdev->flags))))) &&
-            (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
-                             && !test_bit(R5_LOCKED, &qdev->flags)
-                             && (test_bit(R5_UPTODATE, &qdev->flags) ||
-                                 test_bit(R5_Discard, &qdev->flags))))))
-                handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
-
-        /* Now we might consider reading some blocks, either to check/generate
-         * parity, or to satisfy requests
-         * or to load a block that is being partially written.
-         */
-        if (s.to_read || s.non_overwrite
-            || (conf->level == 6 && s.to_write && s.failed)
-            || (s.syncing && (s.uptodate + s.compute < disks))
-            || s.replacing
-            || s.expanding)
-                handle_stripe_fill(sh, &s, disks);
-
         /* Now we check to see if any write operations have recently
          * completed
          */
@@ -3561,6 +3530,40 @@ static void handle_stripe(struct stripe_head *sh)
                         s.dec_preread_active = 1;
         }
 
+        /*
+         * might be able to return some write requests if the parity blocks
+         * are safe, or on a failed drive
+         */
+        pdev = &sh->dev[sh->pd_idx];
+        s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
+                || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
+        qdev = &sh->dev[sh->qd_idx];
+        s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
+                || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
+                || conf->level < 6;
+
+        if (s.written &&
+            (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
+                             && !test_bit(R5_LOCKED, &pdev->flags)
+                             && (test_bit(R5_UPTODATE, &pdev->flags) ||
+                                 test_bit(R5_Discard, &pdev->flags))))) &&
+            (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
+                             && !test_bit(R5_LOCKED, &qdev->flags)
+                             && (test_bit(R5_UPTODATE, &qdev->flags) ||
+                                 test_bit(R5_Discard, &qdev->flags))))))
+                handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
+
+        /* Now we might consider reading some blocks, either to check/generate
+         * parity, or to satisfy requests
+         * or to load a block that is being partially written.
+         */
+        if (s.to_read || s.non_overwrite
+            || (conf->level == 6 && s.to_write && s.failed)
+            || (s.syncing && (s.uptodate + s.compute < disks))
+            || s.replacing
+            || s.expanding)
+                handle_stripe_fill(sh, &s, disks);
+
         /* Now to consider new write requests and what else, if anything
          * should be read.  We do not handle new writes when:
          * 1/ A 'write' operation (copy+xor) is already in flight.
@@ -5529,6 +5532,10 @@ static int run(struct mddev *mddev)
                  * discard data disk but write parity disk
                  */
                 stripe = stripe * PAGE_SIZE;
+                /* Round up to power of 2, as discard handling
+                 * currently assumes that */
+                while ((stripe-1) & stripe)
+                        stripe = (stripe | (stripe-1)) + 1;
                 mddev->queue->limits.discard_alignment = stripe;
                 mddev->queue->limits.discard_granularity = stripe;
                 /*