md/raid5: Move code for finishing a reconstruction into handle_stripe.

Prior to commit ab69ae12 the code in handle_stripe5 and
handle_stripe6 to "Finish reconstruct operations initiated by the
expansion process" was identical.
That commit added an identical stanza of code to each function, but in
different places.  That was careless.

The raid5 code was correct, so move that out into handle_stripe and
remove raid6 version.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>

drivers/md/raid5.c

@@ -2998,7 +2998,7 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh)
  *
  */
 
-static void handle_stripe5(struct stripe_head *sh, struct stripe_head_state *s)
+static int handle_stripe5(struct stripe_head *sh, struct stripe_head_state *s)
 {
 	raid5_conf_t *conf = sh->raid_conf;
 	int disks = sh->disks, i;
@@ -3080,7 +3080,7 @@ static void handle_stripe5(struct stripe_head *sh, struct stripe_head_state *s)
 		if (s->syncing || s->expanding || s->expanded ||
 		    s->to_write || s->written) {
 			set_bit(STRIPE_HANDLE, &sh->state);
-			return;
+			return 1;
 		}
 		/* There is nothing for the blocked_rdev to block */
 		rdev_dec_pending(s->blocked_rdev, conf->mddev);
@@ -3204,54 +3204,10 @@ static void handle_stripe5(struct stripe_head *sh, struct stripe_head_state *s)
 			s->locked++;
 		}
 	}
-
-	/* Finish reconstruct operations initiated by the expansion process */
-	if (sh->reconstruct_state == reconstruct_state_result) {
-		struct stripe_head *sh2
-			= get_active_stripe(conf, sh->sector, 1, 1, 1);
-		if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
-			/* sh cannot be written until sh2 has been read.
-			 * so arrange for sh to be delayed a little
-			 */
-			set_bit(STRIPE_DELAYED, &sh->state);
-			set_bit(STRIPE_HANDLE, &sh->state);
-			if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
-					      &sh2->state))
-				atomic_inc(&conf->preread_active_stripes);
-			release_stripe(sh2);
-			return;
-		}
-		if (sh2)
-			release_stripe(sh2);
-
-		sh->reconstruct_state = reconstruct_state_idle;
-		clear_bit(STRIPE_EXPANDING, &sh->state);
-		for (i = conf->raid_disks; i--; ) {
-			set_bit(R5_Wantwrite, &sh->dev[i].flags);
-			set_bit(R5_LOCKED, &sh->dev[i].flags);
-			s->locked++;
-		}
-	}
-
-	if (s->expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
-	    !sh->reconstruct_state) {
-		/* Need to write out all blocks after computing parity */
-		sh->disks = conf->raid_disks;
-		stripe_set_idx(sh->sector, conf, 0, sh);
-		schedule_reconstruction(sh, s, 1, 1);
-	} else if (s->expanded && !sh->reconstruct_state && s->locked == 0) {
-		clear_bit(STRIPE_EXPAND_READY, &sh->state);
-		atomic_dec(&conf->reshape_stripes);
-		wake_up(&conf->wait_for_overlap);
-		md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
-	}
-
-	if (s->expanding && s->locked == 0 &&
-	    !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
-		handle_stripe_expansion(conf, sh);
+	return 0;
 }
 
-static void handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s)
+static int handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s)
 {
 	raid5_conf_t *conf = sh->raid_conf;
 	int disks = sh->disks;
@@ -3334,7 +3290,7 @@ static void handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s)
 		if (s->syncing || s->expanding || s->expanded ||
 		    s->to_write || s->written) {
 			set_bit(STRIPE_HANDLE, &sh->state);
-			return;
+			return 1;
 		}
 		/* There is nothing for the blocked_rdev to block */
 		rdev_dec_pending(s->blocked_rdev, conf->mddev);
@@ -3467,56 +3423,14 @@ static void handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s)
 				}
 			}
 		}
-
-	/* Finish reconstruct operations initiated by the expansion process */
-	if (sh->reconstruct_state == reconstruct_state_result) {
-		sh->reconstruct_state = reconstruct_state_idle;
-		clear_bit(STRIPE_EXPANDING, &sh->state);
-		for (i = conf->raid_disks; i--; ) {
-			set_bit(R5_Wantwrite, &sh->dev[i].flags);
-			set_bit(R5_LOCKED, &sh->dev[i].flags);
-			s->locked++;
-		}
-	}
-
-	if (s->expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
-	    !sh->reconstruct_state) {
-		struct stripe_head *sh2
-			= get_active_stripe(conf, sh->sector, 1, 1, 1);
-		if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
-			/* sh cannot be written until sh2 has been read.
-			 * so arrange for sh to be delayed a little
-			 */
-			set_bit(STRIPE_DELAYED, &sh->state);
-			set_bit(STRIPE_HANDLE, &sh->state);
-			if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
-					      &sh2->state))
-				atomic_inc(&conf->preread_active_stripes);
-			release_stripe(sh2);
-			return;
-		}
-		if (sh2)
-			release_stripe(sh2);
-
-		/* Need to write out all blocks after computing P&Q */
-		sh->disks = conf->raid_disks;
-		stripe_set_idx(sh->sector, conf, 0, sh);
-		schedule_reconstruction(sh, s, 1, 1);
-	} else if (s->expanded && !sh->reconstruct_state && s->locked == 0) {
-		clear_bit(STRIPE_EXPAND_READY, &sh->state);
-		atomic_dec(&conf->reshape_stripes);
-		wake_up(&conf->wait_for_overlap);
-		md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
-	}
-
-	if (s->expanding && s->locked == 0 &&
-	    !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
-		handle_stripe_expansion(conf, sh);
+	return 0;
 }
 
 static void handle_stripe(struct stripe_head *sh)
 {
 	struct stripe_head_state s;
+	int done;
+	int i;
 	raid5_conf_t *conf = sh->raid_conf;
 
 	clear_bit(STRIPE_HANDLE, &sh->state);
@@ -3545,11 +3459,58 @@ static void handle_stripe(struct stripe_head *sh)
 	s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
 
 	if (conf->level == 6)
-		handle_stripe6(sh, &s);
+		done = handle_stripe6(sh, &s);
 	else
-		handle_stripe5(sh, &s);
+		done = handle_stripe5(sh, &s);
+
+	if (done)
+		goto finish;
+	/* Finish reconstruct operations initiated by the expansion process */
+	if (sh->reconstruct_state == reconstruct_state_result) {
+		struct stripe_head *sh_src
+			= get_active_stripe(conf, sh->sector, 1, 1, 1);
+		if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) {
+			/* sh cannot be written until sh_src has been read.
+			 * so arrange for sh to be delayed a little
+			 */
+			set_bit(STRIPE_DELAYED, &sh->state);
+			set_bit(STRIPE_HANDLE, &sh->state);
+			if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
+					      &sh_src->state))
+				atomic_inc(&conf->preread_active_stripes);
+			release_stripe(sh_src);
+			goto finish;
+		}
+		if (sh_src)
+			release_stripe(sh_src);
+
+		sh->reconstruct_state = reconstruct_state_idle;
+		clear_bit(STRIPE_EXPANDING, &sh->state);
+		for (i = conf->raid_disks; i--; ) {
+			set_bit(R5_Wantwrite, &sh->dev[i].flags);
+			set_bit(R5_LOCKED, &sh->dev[i].flags);
+			s.locked++;
+		}
+	}
 
+	if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
+	    !sh->reconstruct_state) {
+		/* Need to write out all blocks after computing parity */
+		sh->disks = conf->raid_disks;
+		stripe_set_idx(sh->sector, conf, 0, sh);
+		schedule_reconstruction(sh, &s, 1, 1);
+	} else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
+		clear_bit(STRIPE_EXPAND_READY, &sh->state);
+		atomic_dec(&conf->reshape_stripes);
+		wake_up(&conf->wait_for_overlap);
+		md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
+	}
+
+	if (s.expanding && s.locked == 0 &&
+	    !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
+		handle_stripe_expansion(conf, sh);
 
+finish:
 	/* wait for this device to become unblocked */
 	if (unlikely(s.blocked_rdev))
 		md_wait_for_blocked_rdev(s.blocked_rdev, conf->mddev);