1 files changed, 40 insertions, 36 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 456c3c2c961..442622067ca 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1618,7 +1618,7 @@ static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
 }
 
 static void
-handle_write_operations5(struct stripe_head *sh, struct stripe_head_state *s,
+schedule_reconstruction5(struct stripe_head *sh, struct stripe_head_state *s,
 			 int rcw, int expand)
 {
 	int i, pd_idx = sh->pd_idx, disks = sh->disks;
@@ -1783,7 +1783,7 @@ static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks)
 }
 
 static void
-handle_requests_to_failed_array(raid5_conf_t *conf, struct stripe_head *sh,
+handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
 				struct stripe_head_state *s, int disks,
 				struct bio **return_bi)
 {
@@ -1874,23 +1874,28 @@ handle_requests_to_failed_array(raid5_conf_t *conf, struct stripe_head *sh,
 			md_wakeup_thread(conf->mddev->thread);
 }
 
-/* __handle_issuing_new_read_requests5 - returns 0 if there are no more disks
- * to process
+/* fetch_block5 - checks the given member device to see if its data needs
+ * to be read or computed to satisfy a request.
+ *
+ * Returns 1 when no more member devices need to be checked, otherwise returns
+ * 0 to tell the loop in handle_stripe_fill5 to continue
  */
-static int __handle_issuing_new_read_requests5(struct stripe_head *sh,
-			struct stripe_head_state *s, int disk_idx, int disks)
+static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,
+			int disk_idx, int disks)
 {
 	struct r5dev *dev = &sh->dev[disk_idx];
 	struct r5dev *failed_dev = &sh->dev[s->failed_num];
 
 	/* is the data in this block needed, and can we get it? */
 	if (!test_bit(R5_LOCKED, &dev->flags) &&
-	    !test_bit(R5_UPTODATE, &dev->flags) && (dev->toread ||
-	    (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
-	     s->syncing || s->expanding || (s->failed &&
-	     (failed_dev->toread || (failed_dev->towrite &&
-	     !test_bit(R5_OVERWRITE, &failed_dev->flags)
-	     ))))) {
+	    !test_bit(R5_UPTODATE, &dev->flags) &&
+	    (dev->toread ||
+	     (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
+	     s->syncing || s->expanding ||
+	     (s->failed &&
+	      (failed_dev->toread ||
+	       (failed_dev->towrite &&
+		!test_bit(R5_OVERWRITE, &failed_dev->flags)))))) {
 		/* We would like to get this block, possibly by computing it,
 		 * otherwise read it if the backing disk is insync
 		 */
@@ -1908,7 +1913,7 @@ static int __handle_issuing_new_read_requests5(struct stripe_head *sh,
 			 * subsequent operation.
 			 */
 			s->uptodate++;
-			return 0; /* uptodate + compute == disks */
+			return 1; /* uptodate + compute == disks */
 		} else if (test_bit(R5_Insync, &dev->flags)) {
 			set_bit(R5_LOCKED, &dev->flags);
 			set_bit(R5_Wantread, &dev->flags);
@@ -1918,10 +1923,13 @@ static int __handle_issuing_new_read_requests5(struct stripe_head *sh,
 		}
 	}
 
-	return ~0;
+	return 0;
 }
 
-static void handle_issuing_new_read_requests5(struct stripe_head *sh,
+/**
+ * handle_stripe_fill5 - read or compute data to satisfy pending requests.
+ */
+static void handle_stripe_fill5(struct stripe_head *sh,
 			struct stripe_head_state *s, int disks)
 {
 	int i;
@@ -1931,16 +1939,14 @@ static void handle_issuing_new_read_requests5(struct stripe_head *sh,
 	 * midst of changing due to a write
 	 */
 	if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
-	    !sh->reconstruct_state) {
+	    !sh->reconstruct_state)
 		for (i = disks; i--; )
-			if (__handle_issuing_new_read_requests5(
-				sh, s, i, disks) == 0)
+			if (fetch_block5(sh, s, i, disks))
 				break;
-	}
 	set_bit(STRIPE_HANDLE, &sh->state);
 }
 
-static void handle_issuing_new_read_requests6(struct stripe_head *sh,
+static void handle_stripe_fill6(struct stripe_head *sh,
 			struct stripe_head_state *s, struct r6_state *r6s,
 			int disks)
 {
@@ -1999,12 +2005,12 @@ static void handle_issuing_new_read_requests6(struct stripe_head *sh,
 }
 
 
-/* handle_completed_write_requests
+/* handle_stripe_clean_event
  * any written block on an uptodate or failed drive can be returned.
  * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
  * never LOCKED, so we don't need to test 'failed' directly.
  */
-static void handle_completed_write_requests(raid5_conf_t *conf,
+static void handle_stripe_clean_event(raid5_conf_t *conf,
 	struct stripe_head *sh, int disks, struct bio **return_bi)
 {
 	int i;
@@ -2049,7 +2055,7 @@ static void handle_completed_write_requests(raid5_conf_t *conf,
 			md_wakeup_thread(conf->mddev->thread);
 }
 
-static void handle_issuing_new_write_requests5(raid5_conf_t *conf,
+static void handle_stripe_dirtying5(raid5_conf_t *conf,
 		struct stripe_head *sh,	struct stripe_head_state *s, int disks)
 {
 	int rmw = 0, rcw = 0, i;
@@ -2136,10 +2142,10 @@ static void handle_issuing_new_write_requests5(raid5_conf_t *conf,
 	if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
 	    (s->locked == 0 && (rcw == 0 || rmw == 0) &&
 	    !test_bit(STRIPE_BIT_DELAY, &sh->state)))
-		handle_write_operations5(sh, s, rcw == 0, 0);
+		schedule_reconstruction5(sh, s, rcw == 0, 0);
 }
 
-static void handle_issuing_new_write_requests6(raid5_conf_t *conf,
+static void handle_stripe_dirtying6(raid5_conf_t *conf,
 		struct stripe_head *sh,	struct stripe_head_state *s,
 		struct r6_state *r6s, int disks)
 {
@@ -2597,8 +2603,7 @@ static void handle_stripe5(struct stripe_head *sh)
 	 * need to be failed
 	 */
 	if (s.failed > 1 && s.to_read+s.to_write+s.written)
-		handle_requests_to_failed_array(conf, sh, &s, disks,
-						&return_bi);
+		handle_failed_stripe(conf, sh, &s, disks, &return_bi);
 	if (s.failed > 1 && s.syncing) {
 		md_done_sync(conf->mddev, STRIPE_SECTORS,0);
 		clear_bit(STRIPE_SYNCING, &sh->state);
@@ -2614,7 +2619,7 @@ static void handle_stripe5(struct stripe_head *sh)
 	       !test_bit(R5_LOCKED, &dev->flags) &&
 	       test_bit(R5_UPTODATE, &dev->flags)) ||
 	       (s.failed == 1 && s.failed_num == sh->pd_idx)))
-		handle_completed_write_requests(conf, sh, disks, &return_bi);
+		handle_stripe_clean_event(conf, sh, disks, &return_bi);
 
 	/* Now we might consider reading some blocks, either to check/generate
 	 * parity, or to satisfy requests
@@ -2622,7 +2627,7 @@ static void handle_stripe5(struct stripe_head *sh)
 	 */
 	if (s.to_read || s.non_overwrite ||
 	    (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
-		handle_issuing_new_read_requests5(sh, &s, disks);
+		handle_stripe_fill5(sh, &s, disks);
 
 	/* Now we check to see if any write operations have recently
 	 * completed
@@ -2666,7 +2671,7 @@ static void handle_stripe5(struct stripe_head *sh)
 	 *    block.
 	 */
 	if (s.to_write && !sh->reconstruct_state && !sh->check_state)
-		handle_issuing_new_write_requests5(conf, sh, &s, disks);
+		handle_stripe_dirtying5(conf, sh, &s, disks);
 
 	/* maybe we need to check and possibly fix the parity for this stripe
 	 * Any reads will already have been scheduled, so we just see if enough
@@ -2722,7 +2727,7 @@ static void handle_stripe5(struct stripe_head *sh)
 		sh->disks = conf->raid_disks;
 		sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
 			conf->raid_disks);
-		handle_write_operations5(sh, &s, 1, 1);
+		schedule_reconstruction5(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);
@@ -2854,8 +2859,7 @@ static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
 	 * might need to be failed
 	 */
 	if (s.failed > 2 && s.to_read+s.to_write+s.written)
-		handle_requests_to_failed_array(conf, sh, &s, disks,
-						&return_bi);
+		handle_failed_stripe(conf, sh, &s, disks, &return_bi);
 	if (s.failed > 2 && s.syncing) {
 		md_done_sync(conf->mddev, STRIPE_SECTORS,0);
 		clear_bit(STRIPE_SYNCING, &sh->state);
@@ -2880,7 +2884,7 @@ static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
 	     ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
 			     && !test_bit(R5_LOCKED, &qdev->flags)
 			     && test_bit(R5_UPTODATE, &qdev->flags)))))
-		handle_completed_write_requests(conf, sh, disks, &return_bi);
+		handle_stripe_clean_event(conf, sh, disks, &return_bi);
 
 	/* Now we might consider reading some blocks, either to check/generate
 	 * parity, or to satisfy requests
@@ -2888,11 +2892,11 @@ static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
 	 */
 	if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
 	    (s.syncing && (s.uptodate < disks)) || s.expanding)
-		handle_issuing_new_read_requests6(sh, &s, &r6s, disks);
+		handle_stripe_fill6(sh, &s, &r6s, disks);
 
 	/* now to consider writing and what else, if anything should be read */
 	if (s.to_write)
-		handle_issuing_new_write_requests6(conf, sh, &s, &r6s, disks);
+		handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
 
 	/* maybe we need to check and possibly fix the parity for this stripe
 	 * Any reads will already have been scheduled, so we just see if enough