--- 7eda483d7b5aa0cd5e5bd96d149cca6fe2fc8f16
+++ 41ecbb2347f2d3171f7645782ab4e5a39621c84d
@@ -1135,7 +1135,7 @@ int btrfs_rm_device(struct btrfs_root *r
 		root->fs_info->avail_metadata_alloc_bits;
 
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
-	    root->fs_info->fs_devices->rw_devices <= 4) {
+	    root->fs_info->fs_devices->num_devices <= 4) {
 		printk(KERN_ERR "btrfs: unable to go below four devices "
 		       "on raid10\n");
 		ret = -EINVAL;
@@ -1143,7 +1143,7 @@ int btrfs_rm_device(struct btrfs_root *r
 	}
 
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
-	    root->fs_info->fs_devices->rw_devices <= 2) {
+	    root->fs_info->fs_devices->num_devices <= 2) {
 		printk(KERN_ERR "btrfs: unable to go below two "
 		       "devices on raid1\n");
 		ret = -EINVAL;
@@ -1434,8 +1434,8 @@ int btrfs_init_new_device(struct btrfs_r
 		return -EINVAL;
 
 	bdev = open_bdev_exclusive(device_path, 0, root->fs_info->bdev_holder);
-	if (!bdev)
-		return -EIO;
+	if (IS_ERR(bdev))
+		return PTR_ERR(bdev);
 
 	if (root->fs_info->fs_devices->seeding) {
 		seeding_dev = 1;
@@ -2209,7 +2209,7 @@ static int __btrfs_alloc_chunk(struct bt
 		max_chunk_size = 10 * calc_size;
 		min_stripe_size = 64 * 1024 * 1024;
 	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
-		max_chunk_size = 4 * calc_size;
+		max_chunk_size = 256 * 1024 * 1024;
 		min_stripe_size = 32 * 1024 * 1024;
 	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
 		calc_size = 8 * 1024 * 1024;
@@ -2538,6 +2538,11 @@ int btrfs_chunk_readonly(struct btrfs_ro
 	if (!em)
 		return 1;
 
+	if (btrfs_test_opt(root, DEGRADED)) {
+		free_extent_map(em);
+		return 0;
+	}
+
 	map = (struct map_lookup *)em->bdev;
 	for (i = 0; i < map->num_stripes; i++) {
 		if (!map->stripes[i].dev->writeable) {
@@ -2649,8 +2654,10 @@ again:
 	em = lookup_extent_mapping(em_tree, logical, *length);
 	read_unlock(&em_tree->lock);
 
-	if (!em && unplug_page)
+	if (!em && unplug_page) {
+		kfree(multi);
 		return 0;
+	}
 
 	if (!em) {
 		printk(KERN_CRIT "unable to find logical %llu len %llu\n",