diff --git a/fs/btrfs/block-rsv.c b/fs/btrfs/block-rsv.c
index 96cf7a162987..e823230c09b7 100644
--- a/fs/btrfs/block-rsv.c
+++ b/fs/btrfs/block-rsv.c
@@ -419,6 +419,9 @@ void btrfs_init_root_block_rsv(struct btrfs_root *root)
 	case BTRFS_TREE_LOG_OBJECTID:
 		root->block_rsv = &fs_info->treelog_rsv;
 		break;
+	case BTRFS_REMAP_TREE_OBJECTID:
+		root->block_rsv = &fs_info->remap_block_rsv;
+		break;
 	default:
 		root->block_rsv = NULL;
 		break;
@@ -432,6 +435,9 @@ void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info)
 	space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
 	fs_info->chunk_block_rsv.space_info = space_info;
 
+	space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA_REMAP);
+	fs_info->remap_block_rsv.space_info = space_info;
+
 	space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
 	fs_info->global_block_rsv.space_info = space_info;
 	fs_info->trans_block_rsv.space_info = space_info;
@@ -458,6 +464,8 @@ void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info)
 	WARN_ON(fs_info->trans_block_rsv.reserved > 0);
 	WARN_ON(fs_info->chunk_block_rsv.size > 0);
 	WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
+	WARN_ON(fs_info->remap_block_rsv.size > 0);
+	WARN_ON(fs_info->remap_block_rsv.reserved > 0);
 	WARN_ON(fs_info->delayed_block_rsv.size > 0);
 	WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
 	WARN_ON(fs_info->delayed_refs_rsv.reserved > 0);
diff --git a/fs/btrfs/block-rsv.h b/fs/btrfs/block-rsv.h
index 79ae9d05cd91..8359fb96bc3c 100644
--- a/fs/btrfs/block-rsv.h
+++ b/fs/btrfs/block-rsv.h
@@ -22,6 +22,7 @@ enum btrfs_rsv_type {
 	BTRFS_BLOCK_RSV_DELALLOC,
 	BTRFS_BLOCK_RSV_TRANS,
 	BTRFS_BLOCK_RSV_CHUNK,
+	BTRFS_BLOCK_RSV_REMAP,
 	BTRFS_BLOCK_RSV_DELOPS,
 	BTRFS_BLOCK_RSV_DELREFS,
 	BTRFS_BLOCK_RSV_TREELOG,
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index faa1c2c20ecd..922e69038d81 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2751,6 +2751,7 @@ void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
 			     BTRFS_BLOCK_RSV_GLOBAL);
 	btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
 	btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
+	btrfs_init_block_rsv(&fs_info->remap_block_rsv, BTRFS_BLOCK_RSV_REMAP);
 	btrfs_init_block_rsv(&fs_info->treelog_rsv, BTRFS_BLOCK_RSV_TREELOG);
 	btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
 	btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
diff --git a/fs/btrfs/fs.h b/fs/btrfs/fs.h
index e3e5e52e97a2..195428ecfd75 100644
--- a/fs/btrfs/fs.h
+++ b/fs/btrfs/fs.h
@@ -509,6 +509,8 @@ struct btrfs_fs_info {
 	struct btrfs_block_rsv trans_block_rsv;
 	/* Block reservation for chunk tree */
 	struct btrfs_block_rsv chunk_block_rsv;
+	/* Block reservation for remap tree. */
+	struct btrfs_block_rsv remap_block_rsv;
 	/* Block reservation for delayed operations */
 	struct btrfs_block_rsv delayed_block_rsv;
 	/* Block reservation for delayed refs */
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index 1d76242f5e0d..2c9cf1ab232b 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -215,7 +215,7 @@ static u64 calc_chunk_size(const struct btrfs_fs_info *fs_info, u64 flags)
 
 	if (flags & BTRFS_BLOCK_GROUP_DATA)
 		return BTRFS_MAX_DATA_CHUNK_SIZE;
-	else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+	else if (flags & (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA_REMAP))
 		return SZ_32M;
 
 	/* Handle BTRFS_BLOCK_GROUP_METADATA */
@@ -348,6 +348,8 @@ int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
 	if (mixed) {
 		flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
 		ret = create_space_info(fs_info, flags);
+		if (ret)
+			goto out;
 	} else {
 		flags = BTRFS_BLOCK_GROUP_METADATA;
 		ret = create_space_info(fs_info, flags);
@@ -356,7 +358,15 @@ int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
 
 		flags = BTRFS_BLOCK_GROUP_DATA;
 		ret = create_space_info(fs_info, flags);
+		if (ret)
+			goto out;
 	}
+
+	if (features & BTRFS_FEATURE_INCOMPAT_REMAP_TREE) {
+		flags = BTRFS_BLOCK_GROUP_METADATA_REMAP;
+		ret = create_space_info(fs_info, flags);
+	}
+
 out:
 	return ret;
 }
@@ -611,6 +621,7 @@ static void dump_global_block_rsv(struct btrfs_fs_info *fs_info)
 	DUMP_BLOCK_RSV(fs_info, global_block_rsv);
 	DUMP_BLOCK_RSV(fs_info, trans_block_rsv);
 	DUMP_BLOCK_RSV(fs_info, chunk_block_rsv);
+	DUMP_BLOCK_RSV(fs_info, remap_block_rsv);
 	DUMP_BLOCK_RSV(fs_info, delayed_block_rsv);
 	DUMP_BLOCK_RSV(fs_info, delayed_refs_rsv);
 }
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 8834a1dd499c..27bfb7b55ec4 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -1929,6 +1929,8 @@ static const char *alloc_name(struct btrfs_space_info *space_info)
 	case BTRFS_BLOCK_GROUP_SYSTEM:
 		ASSERT(space_info->subgroup_id == BTRFS_SUB_GROUP_PRIMARY);
 		return "system";
+	case BTRFS_BLOCK_GROUP_METADATA_REMAP:
+		return "metadata-remap";
 	default:
 		WARN_ON(1);
 		return "invalid-combination";
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index aedc208a95b8..a6c158cd8fcd 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -748,17 +748,26 @@ static int check_block_group_item(struct extent_buffer *leaf,
 		return -EUCLEAN;
 	}
 
+	if (unlikely(flags & BTRFS_BLOCK_GROUP_METADATA_REMAP &&
+		     !btrfs_fs_incompat(fs_info, REMAP_TREE))) {
+		block_group_err(leaf, slot,
+"invalid flags, have 0x%llx (METADATA_REMAP flag set) but no remap-tree incompat flag",
+				flags);
+		return -EUCLEAN;
+	}
+
 	type = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
 	if (unlikely(type != BTRFS_BLOCK_GROUP_DATA &&
 		     type != BTRFS_BLOCK_GROUP_METADATA &&
 		     type != BTRFS_BLOCK_GROUP_SYSTEM &&
+		     type != BTRFS_BLOCK_GROUP_METADATA_REMAP &&
 		     type != (BTRFS_BLOCK_GROUP_METADATA |
 			      BTRFS_BLOCK_GROUP_DATA))) {
 		block_group_err(leaf, slot,
-"invalid type, have 0x%llx (%lu bits set) expect either 0x%llx, 0x%llx, 0x%llx or 0x%llx",
+"invalid type, have 0x%llx (%lu bits set) expect either 0x%llx, 0x%llx, 0x%llx, 0x%llx or 0x%llx",
 			type, hweight64(type),
 			BTRFS_BLOCK_GROUP_DATA, BTRFS_BLOCK_GROUP_METADATA,
-			BTRFS_BLOCK_GROUP_SYSTEM,
+			BTRFS_BLOCK_GROUP_SYSTEM, BTRFS_BLOCK_GROUP_METADATA_REMAP,
 			BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA);
 		return -EUCLEAN;
 	}
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d2b7352eb7cb..eda6505f3ee5 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -231,6 +231,9 @@ void btrfs_describe_block_groups(u64 bg_flags, char *buf, u32 size_buf)
 	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_DATA, "data");
 	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_SYSTEM, "system");
 	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_METADATA, "metadata");
+	/* Block groups containing the remap tree. */
+	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_METADATA_REMAP, "metadata-remap");
+	/* Block group that has been remapped. */
 	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_REMAPPED, "remapped");
 
 	DESCRIBE_FLAG(BTRFS_AVAIL_ALLOC_BIT_SINGLE, "single");
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 59347a4bb185..e4b3cb50f94a 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -58,7 +58,6 @@ static_assert(ilog2(BTRFS_STRIPE_LEN) == BTRFS_STRIPE_LEN_SHIFT);
  */
 static_assert(const_ffs(BTRFS_BLOCK_GROUP_RAID0) <
 	      const_ffs(BTRFS_BLOCK_GROUP_PROFILE_MASK & ~BTRFS_BLOCK_GROUP_RAID0));
-static_assert(ilog2(BTRFS_BLOCK_GROUP_RAID0) > ilog2(BTRFS_BLOCK_GROUP_TYPE_MASK));
 
 /* ilog2() can handle both constants and variables */
 #define BTRFS_BG_FLAG_TO_INDEX(profile)					\
@@ -80,6 +79,15 @@ enum btrfs_raid_types {
 	BTRFS_NR_RAID_TYPES
 };
 
+static_assert(BTRFS_RAID_RAID0 == 1);
+static_assert(BTRFS_RAID_RAID1 == 2);
+static_assert(BTRFS_RAID_DUP == 3);
+static_assert(BTRFS_RAID_RAID10 == 4);
+static_assert(BTRFS_RAID_RAID5 == 5);
+static_assert(BTRFS_RAID_RAID6 == 6);
+static_assert(BTRFS_RAID_RAID1C3 == 7);
+static_assert(BTRFS_RAID_RAID1C4 == 8);
+
 /*
  * Use sequence counter to get consistent device stat data on
  * 32-bit processors.
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index f011d34cb699..76578426671c 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -1169,12 +1169,14 @@ struct btrfs_dev_replace_item {
 #define BTRFS_BLOCK_GROUP_RAID1C3       (1ULL << 9)
 #define BTRFS_BLOCK_GROUP_RAID1C4       (1ULL << 10)
 #define BTRFS_BLOCK_GROUP_REMAPPED      (1ULL << 11)
+#define BTRFS_BLOCK_GROUP_METADATA_REMAP (1ULL << 12)
 #define BTRFS_BLOCK_GROUP_RESERVED	(BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
 					 BTRFS_SPACE_INFO_GLOBAL_RSV)
 
 #define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
 					 BTRFS_BLOCK_GROUP_SYSTEM |  \
-					 BTRFS_BLOCK_GROUP_METADATA)
+					 BTRFS_BLOCK_GROUP_METADATA | \
+					 BTRFS_BLOCK_GROUP_METADATA_REMAP)
 
 #define BTRFS_BLOCK_GROUP_PROFILE_MASK	(BTRFS_BLOCK_GROUP_RAID0 |   \
 					 BTRFS_BLOCK_GROUP_RAID1 |   \