1 files changed, 36 insertions, 55 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 35d12948e0a9..aaa434f0c175 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -49,6 +49,7 @@ static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
 #define raid1_log(md, fmt, args...)				\
 	do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
 
+#define RAID_1_10_NAME "raid1"
 #include "raid1-10.c"
 
 #define START(node) ((node)->start)
@@ -609,7 +610,6 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
 	int choose_first;
 	int choose_next_idle;
 
-	rcu_read_lock();
 	/*
 	 * Check if we can balance. We can balance on the whole
 	 * device if no resync is going on, or below the resync window.
@@ -642,7 +642,7 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
 		unsigned int pending;
 		bool nonrot;
 
-		rdev = rcu_dereference(conf->mirrors[disk].rdev);
+		rdev = conf->mirrors[disk].rdev;
 		if (r1_bio->bios[disk] == IO_BLOCKED
 		    || rdev == NULL
 		    || test_bit(Faulty, &rdev->flags))
@@ -773,7 +773,7 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
 	}
 
 	if (best_disk >= 0) {
-		rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
+		rdev = conf->mirrors[best_disk].rdev;
 		if (!rdev)
 			goto retry;
 		atomic_inc(&rdev->nr_pending);
@@ -784,7 +784,6 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
 
 		conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
 	}
-	rcu_read_unlock();
 	*max_sectors = sectors;
 
 	return best_disk;
@@ -1126,8 +1125,6 @@ static void alloc_behind_master_bio(struct r1bio *r1_bio,
 
 	behind_bio = bio_alloc_bioset(NULL, vcnt, 0, GFP_NOIO,
 				      &r1_bio->mddev->bio_set);
-	if (!behind_bio)
-		return;
 
 	/* discard op, we don't support writezero/writesame yet */
 	if (!bio_has_data(bio)) {
@@ -1235,14 +1232,12 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 
 	if (r1bio_existed) {
 		/* Need to get the block device name carefully */
-		struct md_rdev *rdev;
-		rcu_read_lock();
-		rdev = rcu_dereference(conf->mirrors[r1_bio->read_disk].rdev);
+		struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
+
 		if (rdev)
 			snprintf(b, sizeof(b), "%pg", rdev->bdev);
 		else
 			strcpy(b, "???");
-		rcu_read_unlock();
 	}
 
 	/*
@@ -1396,10 +1391,9 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 
 	disks = conf->raid_disks * 2;
 	blocked_rdev = NULL;
-	rcu_read_lock();
 	max_sectors = r1_bio->sectors;
 	for (i = 0;  i < disks; i++) {
-		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+		struct md_rdev *rdev = conf->mirrors[i].rdev;
 
 		/*
 		 * The write-behind io is only attempted on drives marked as
@@ -1465,7 +1459,6 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 		}
 		r1_bio->bios[i] = bio;
 	}
-	rcu_read_unlock();
 
 	if (unlikely(blocked_rdev)) {
 		/* Wait for this device to become unblocked */
@@ -1617,15 +1610,16 @@ static void raid1_status(struct seq_file *seq, struct mddev *mddev)
 	struct r1conf *conf = mddev->private;
 	int i;
 
+	lockdep_assert_held(&mddev->lock);
+
 	seq_printf(seq, " [%d/%d] [", conf->raid_disks,
 		   conf->raid_disks - mddev->degraded);
-	rcu_read_lock();
 	for (i = 0; i < conf->raid_disks; i++) {
-		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+		struct md_rdev *rdev = READ_ONCE(conf->mirrors[i].rdev);
+
 		seq_printf(seq, "%s",
 			   rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
 	}
-	rcu_read_unlock();
 	seq_printf(seq, "]");
 }
 
@@ -1691,16 +1685,15 @@ static void print_conf(struct r1conf *conf)
 	pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
 		 conf->raid_disks);
 
-	rcu_read_lock();
+	lockdep_assert_held(&conf->mddev->reconfig_mutex);
 	for (i = 0; i < conf->raid_disks; i++) {
-		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+		struct md_rdev *rdev = conf->mirrors[i].rdev;
 		if (rdev)
 			pr_debug(" disk %d, wo:%d, o:%d, dev:%pg\n",
 				 i, !test_bit(In_sync, &rdev->flags),
 				 !test_bit(Faulty, &rdev->flags),
 				 rdev->bdev);
 	}
-	rcu_read_unlock();
 }
 
 static void close_sync(struct r1conf *conf)
@@ -1810,7 +1803,7 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 			 */
 			if (rdev->saved_raid_disk < 0)
 				conf->fullsync = 1;
-			rcu_assign_pointer(p->rdev, rdev);
+			WRITE_ONCE(p->rdev, rdev);
 			break;
 		}
 		if (test_bit(WantReplacement, &p->rdev->flags) &&
@@ -1826,7 +1819,7 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 		rdev->raid_disk = repl_slot;
 		err = 0;
 		conf->fullsync = 1;
-		rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
+		WRITE_ONCE(p[conf->raid_disks].rdev, rdev);
 	}
 
 	print_conf(conf);
@@ -1862,16 +1855,7 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
 			err = -EBUSY;
 			goto abort;
 		}
-		p->rdev = NULL;
-		if (!test_bit(RemoveSynchronized, &rdev->flags)) {
-			synchronize_rcu();
-			if (atomic_read(&rdev->nr_pending)) {
-				/* lost the race, try later */
-				err = -EBUSY;
-				p->rdev = rdev;
-				goto abort;
-			}
-		}
+		WRITE_ONCE(p->rdev, NULL);
 		if (conf->mirrors[conf->raid_disks + number].rdev) {
 			/* We just removed a device that is being replaced.
 			 * Move down the replacement.  We drain all IO before
@@ -1892,7 +1876,7 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
 				goto abort;
 			}
 			clear_bit(Replacement, &repl->flags);
-			p->rdev = repl;
+			WRITE_ONCE(p->rdev, repl);
 			conf->mirrors[conf->raid_disks + number].rdev = NULL;
 			unfreeze_array(conf);
 		}
@@ -2272,16 +2256,24 @@ static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
  *	3.	Performs writes following reads for array synchronising.
  */
 
-static void fix_read_error(struct r1conf *conf, int read_disk,
-			   sector_t sect, int sectors)
+static void fix_read_error(struct r1conf *conf, struct r1bio *r1_bio)
 {
+	sector_t sect = r1_bio->sector;
+	int sectors = r1_bio->sectors;
+	int read_disk = r1_bio->read_disk;
 	struct mddev *mddev = conf->mddev;
+	struct md_rdev *rdev = rcu_dereference(conf->mirrors[read_disk].rdev);
+
+	if (exceed_read_errors(mddev, rdev)) {
+		r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
+		return;
+	}
+
 	while(sectors) {
 		int s = sectors;
 		int d = read_disk;
 		int success = 0;
 		int start;
-		struct md_rdev *rdev;
 
 		if (s > (PAGE_SIZE>>9))
 			s = PAGE_SIZE >> 9;
@@ -2290,8 +2282,7 @@ static void fix_read_error(struct r1conf *conf, int read_disk,
 			sector_t first_bad;
 			int bad_sectors;
 
-			rcu_read_lock();
-			rdev = rcu_dereference(conf->mirrors[d].rdev);
+			rdev = conf->mirrors[d].rdev;
 			if (rdev &&
 			    (test_bit(In_sync, &rdev->flags) ||
 			     (!test_bit(Faulty, &rdev->flags) &&
@@ -2299,15 +2290,14 @@ static void fix_read_error(struct r1conf *conf, int read_disk,
 			    is_badblock(rdev, sect, s,
 					&first_bad, &bad_sectors) == 0) {
 				atomic_inc(&rdev->nr_pending);
-				rcu_read_unlock();
 				if (sync_page_io(rdev, sect, s<<9,
 					 conf->tmppage, REQ_OP_READ, false))
 					success = 1;
 				rdev_dec_pending(rdev, mddev);
 				if (success)
 					break;
-			} else
-				rcu_read_unlock();
+			}
+
 			d++;
 			if (d == conf->raid_disks * 2)
 				d = 0;
@@ -2326,29 +2316,24 @@ static void fix_read_error(struct r1conf *conf, int read_disk,
 			if (d==0)
 				d = conf->raid_disks * 2;
 			d--;
-			rcu_read_lock();
-			rdev = rcu_dereference(conf->mirrors[d].rdev);
+			rdev = conf->mirrors[d].rdev;
 			if (rdev &&
 			    !test_bit(Faulty, &rdev->flags)) {
 				atomic_inc(&rdev->nr_pending);
-				rcu_read_unlock();
 				r1_sync_page_io(rdev, sect, s,
 						conf->tmppage, WRITE);
 				rdev_dec_pending(rdev, mddev);
-			} else
-				rcu_read_unlock();
+			}
 		}
 		d = start;
 		while (d != read_disk) {
 			if (d==0)
 				d = conf->raid_disks * 2;
 			d--;
-			rcu_read_lock();
-			rdev = rcu_dereference(conf->mirrors[d].rdev);
+			rdev = conf->mirrors[d].rdev;
 			if (rdev &&
 			    !test_bit(Faulty, &rdev->flags)) {
 				atomic_inc(&rdev->nr_pending);
-				rcu_read_unlock();
 				if (r1_sync_page_io(rdev, sect, s,
 						    conf->tmppage, READ)) {
 					atomic_add(s, &rdev->corrected_errors);
@@ -2359,8 +2344,7 @@ static void fix_read_error(struct r1conf *conf, int read_disk,
 						rdev->bdev);
 				}
 				rdev_dec_pending(rdev, mddev);
-			} else
-				rcu_read_unlock();
+			}
 		}
 		sectors -= s;
 		sect += s;
@@ -2530,8 +2514,7 @@ static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
 	if (mddev->ro == 0
 	    && !test_bit(FailFast, &rdev->flags)) {
 		freeze_array(conf, 1);
-		fix_read_error(conf, r1_bio->read_disk,
-			       r1_bio->sector, r1_bio->sectors);
+		fix_read_error(conf, r1_bio);
 		unfreeze_array(conf);
 	} else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
 		md_error(mddev, rdev);
@@ -2741,7 +2724,6 @@ static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
 
 	r1_bio = raid1_alloc_init_r1buf(conf);
 
-	rcu_read_lock();
 	/*
 	 * If we get a correctably read error during resync or recovery,
 	 * we might want to read from a different device.  So we
@@ -2762,7 +2744,7 @@ static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
 		struct md_rdev *rdev;
 		bio = r1_bio->bios[i];
 
-		rdev = rcu_dereference(conf->mirrors[i].rdev);
+		rdev = conf->mirrors[i].rdev;
 		if (rdev == NULL ||
 		    test_bit(Faulty, &rdev->flags)) {
 			if (i < conf->raid_disks)
@@ -2820,7 +2802,6 @@ static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
 				bio->bi_opf |= MD_FAILFAST;
 		}
 	}
-	rcu_read_unlock();
 	if (disk < 0)
 		disk = wonly;
 	r1_bio->read_disk = disk;