Merge tag 'md-3.11-fixes' of git://neil.brown.name/md

Pull md bug fixes from NeilBrown:
 "Sorry boss, back at work now boss.  Here's them nice shiny patches ya
  wanted.  All nicely tagged and justified for -stable and everyfing:

  Three bug fixes for md in 3.10

  3.10 wasn't a good release for md.  The bio changes left a couple of
  bugs, and an md "fix" created another one.

  These three patches appear to fix the issues and have been tagged for
  -stable"

* tag 'md-3.11-fixes' of git://neil.brown.name/md:
  md/raid1: fix bio handling problems in process_checks()
  md: Remove recent change which allows devices to skip recovery.
  md/raid10: fix two problems with RAID10 resync.

drivers/md/md.c

@@ -7716,20 +7716,6 @@ static int remove_and_add_spares(struct mddev *mddev,
 			continue;
 
 		rdev->recovery_offset = 0;
-		if (rdev->saved_raid_disk >= 0 && mddev->in_sync) {
-			spin_lock_irq(&mddev->write_lock);
-			if (mddev->in_sync)
-				/* OK, this device, which is in_sync,
-				 * will definitely be noticed before
-				 * the next write, so recovery isn't
-				 * needed.
-				 */
-				rdev->recovery_offset = mddev->recovery_cp;
-			spin_unlock_irq(&mddev->write_lock);
-		}
-		if (mddev->ro && rdev->recovery_offset != MaxSector)
-			/* not safe to add this disk now */
-			continue;
 		if (mddev->pers->
 		    hot_add_disk(mddev, rdev) == 0) {
 			if (sysfs_link_rdev(mddev, rdev))

drivers/md/raid1.c

@@ -1849,6 +1849,36 @@ static int process_checks(struct r1bio *r1_bio)
 	int i;
 	int vcnt;
 
+	/* Fix variable parts of all bios */
+	vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
+	for (i = 0; i < conf->raid_disks * 2; i++) {
+		int j;
+		int size;
+		struct bio *b = r1_bio->bios[i];
+		if (b->bi_end_io != end_sync_read)
+			continue;
+		/* fixup the bio for reuse */
+		bio_reset(b);
+		b->bi_vcnt = vcnt;
+		b->bi_size = r1_bio->sectors << 9;
+		b->bi_sector = r1_bio->sector +
+			conf->mirrors[i].rdev->data_offset;
+		b->bi_bdev = conf->mirrors[i].rdev->bdev;
+		b->bi_end_io = end_sync_read;
+		b->bi_private = r1_bio;
+
+		size = b->bi_size;
+		for (j = 0; j < vcnt ; j++) {
+			struct bio_vec *bi;
+			bi = &b->bi_io_vec[j];
+			bi->bv_offset = 0;
+			if (size > PAGE_SIZE)
+				bi->bv_len = PAGE_SIZE;
+			else
+				bi->bv_len = size;
+			size -= PAGE_SIZE;
+		}
+	}
 	for (primary = 0; primary < conf->raid_disks * 2; primary++)
 		if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
 		    test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
@@ -1857,12 +1887,10 @@ static int process_checks(struct r1bio *r1_bio)
 			break;
 		}
 	r1_bio->read_disk = primary;
-	vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
 	for (i = 0; i < conf->raid_disks * 2; i++) {
 		int j;
 		struct bio *pbio = r1_bio->bios[primary];
 		struct bio *sbio = r1_bio->bios[i];
-		int size;
 
 		if (sbio->bi_end_io != end_sync_read)
 			continue;
@@ -1888,27 +1916,6 @@ static int process_checks(struct r1bio *r1_bio)
 			rdev_dec_pending(conf->mirrors[i].rdev, mddev);
 			continue;
 		}
-		/* fixup the bio for reuse */
-		bio_reset(sbio);
-		sbio->bi_vcnt = vcnt;
-		sbio->bi_size = r1_bio->sectors << 9;
-		sbio->bi_sector = r1_bio->sector +
-			conf->mirrors[i].rdev->data_offset;
-		sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
-		sbio->bi_end_io = end_sync_read;
-		sbio->bi_private = r1_bio;
-
-		size = sbio->bi_size;
-		for (j = 0; j < vcnt ; j++) {
-			struct bio_vec *bi;
-			bi = &sbio->bi_io_vec[j];
-			bi->bv_offset = 0;
-			if (size > PAGE_SIZE)
-				bi->bv_len = PAGE_SIZE;
-			else
-				bi->bv_len = size;
-			size -= PAGE_SIZE;
-		}
 
 		bio_copy_data(sbio, pbio);
 	}

drivers/md/raid10.c

@@ -2097,11 +2097,17 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
 			 * both 'first' and 'i', so we just compare them.
 			 * All vec entries are PAGE_SIZE;
 			 */
-			for (j = 0; j < vcnt; j++)
+			int sectors = r10_bio->sectors;
+			for (j = 0; j < vcnt; j++) {
+				int len = PAGE_SIZE;
+				if (sectors < (len / 512))
+					len = sectors * 512;
 				if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
 					   page_address(tbio->bi_io_vec[j].bv_page),
-					   fbio->bi_io_vec[j].bv_len))
+					   len))
 					break;
+				sectors -= len/512;
+			}
 			if (j == vcnt)
 				continue;
 			atomic64_add(r10_bio->sectors, &mddev->resync_mismatches);
@@ -3407,6 +3413,7 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
 
 		if (bio->bi_end_io == end_sync_read) {
 			md_sync_acct(bio->bi_bdev, nr_sectors);
+			set_bit(BIO_UPTODATE, &bio->bi_flags);
 			generic_make_request(bio);
 		}
 	}