btrfs-progs: build: add alias for check tests
[platform/upstream/btrfs-progs.git] / utils.c
diff --git a/utils.c b/utils.c
index eeff910..72e6ae9 100644 (file)
--- a/utils.c
+++ b/utils.c
@@ -182,9 +182,872 @@ int test_uuid_unique(char *fs_uuid)
 }
 
 /*
+ * Reserve space from free_tree.
+ * The algorithm is very simple, find the first cache_extent with enough space
+ * and allocate from its beginning.
+ */
+static int reserve_free_space(struct cache_tree *free_tree, u64 len,
+                             u64 *ret_start)
+{
+       struct cache_extent *cache;
+       int found = 0;
+
+       ASSERT(ret_start != NULL);
+       cache = first_cache_extent(free_tree);
+       while (cache) {
+               if (cache->size > len) {
+                       found = 1;
+                       *ret_start = cache->start;
+
+                       cache->size -= len;
+                       if (cache->size == 0) {
+                               remove_cache_extent(free_tree, cache);
+                               free(cache);
+                       } else {
+                               cache->start += len;
+                       }
+                       break;
+               }
+               cache = next_cache_extent(cache);
+       }
+       if (!found)
+               return -ENOSPC;
+       return 0;
+}
+
+static inline int write_temp_super(int fd, struct btrfs_super_block *sb,
+                                  u64 sb_bytenr)
+{
+       u32 crc = ~(u32)0;
+       int ret;
+
+       crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
+                             BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+       btrfs_csum_final(crc, &sb->csum[0]);
+       ret = pwrite(fd, sb, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
+       if (ret < BTRFS_SUPER_INFO_SIZE)
+               ret = (ret < 0 ? -errno : -EIO);
+       else
+               ret = 0;
+       return ret;
+}
+
+/*
+ * Setup temporary superblock at cfg->super_bynter
+ * Needed info are extracted from cfg, and root_bytenr, chunk_bytenr
+ *
+ * For now sys chunk array will be empty and dev_item is empty too.
+ * They will be re-initialized at temp chunk tree setup.
+ *
+ * The superblock signature is not valid, denotes a partially created
+ * filesystem, needs to be finalized.
+ */
+static int setup_temp_super(int fd, struct btrfs_mkfs_config *cfg,
+                           u64 root_bytenr, u64 chunk_bytenr)
+{
+       unsigned char chunk_uuid[BTRFS_UUID_SIZE];
+       char super_buf[BTRFS_SUPER_INFO_SIZE];
+       struct btrfs_super_block *super = (struct btrfs_super_block *)super_buf;
+       int ret;
+
+       memset(super_buf, 0, BTRFS_SUPER_INFO_SIZE);
+       cfg->num_bytes = round_down(cfg->num_bytes, cfg->sectorsize);
+
+       if (*cfg->fs_uuid) {
+               if (uuid_parse(cfg->fs_uuid, super->fsid) != 0) {
+                       error("cound not parse UUID: %s", cfg->fs_uuid);
+                       ret = -EINVAL;
+                       goto out;
+               }
+               if (!test_uuid_unique(cfg->fs_uuid)) {
+                       error("non-unique UUID: %s", cfg->fs_uuid);
+                       ret = -EINVAL;
+                       goto out;
+               }
+       } else {
+               uuid_generate(super->fsid);
+               uuid_unparse(super->fsid, cfg->fs_uuid);
+       }
+       uuid_generate(chunk_uuid);
+       uuid_unparse(chunk_uuid, cfg->chunk_uuid);
+
+       btrfs_set_super_bytenr(super, cfg->super_bytenr);
+       btrfs_set_super_num_devices(super, 1);
+       btrfs_set_super_magic(super, BTRFS_MAGIC_PARTIAL);
+       btrfs_set_super_generation(super, 1);
+       btrfs_set_super_root(super, root_bytenr);
+       btrfs_set_super_chunk_root(super, chunk_bytenr);
+       btrfs_set_super_total_bytes(super, cfg->num_bytes);
+       /*
+        * Temporary filesystem will only have 6 tree roots:
+        * chunk tree, root tree, extent_tree, device tree, fs tree
+        * and csum tree.
+        */
+       btrfs_set_super_bytes_used(super, 6 * cfg->nodesize);
+       btrfs_set_super_sectorsize(super, cfg->sectorsize);
+       btrfs_set_super_leafsize(super, cfg->nodesize);
+       btrfs_set_super_nodesize(super, cfg->nodesize);
+       btrfs_set_super_stripesize(super, cfg->stripesize);
+       btrfs_set_super_csum_type(super, BTRFS_CSUM_TYPE_CRC32);
+       btrfs_set_super_chunk_root(super, chunk_bytenr);
+       btrfs_set_super_cache_generation(super, -1);
+       btrfs_set_super_incompat_flags(super, cfg->features);
+       if (cfg->label)
+               __strncpy_null(super->label, cfg->label, BTRFS_LABEL_SIZE - 1);
+
+       /* Sys chunk array will be re-initialized at chunk tree init time */
+       super->sys_chunk_array_size = 0;
+
+       ret = write_temp_super(fd, super, cfg->super_bytenr);
+out:
+       return ret;
+}
+
+/*
+ * Setup an extent buffer for tree block.
+ */
+static int setup_temp_extent_buffer(struct extent_buffer *buf,
+                                   struct btrfs_mkfs_config *cfg,
+                                   u64 bytenr, u64 owner)
+{
+       unsigned char fsid[BTRFS_FSID_SIZE];
+       unsigned char chunk_uuid[BTRFS_UUID_SIZE];
+       int ret;
+
+       ret = uuid_parse(cfg->fs_uuid, fsid);
+       if (ret)
+               return -EINVAL;
+       ret = uuid_parse(cfg->chunk_uuid, chunk_uuid);
+       if (ret)
+               return -EINVAL;
+
+       memset(buf->data, 0, cfg->nodesize);
+       buf->len = cfg->nodesize;
+       btrfs_set_header_bytenr(buf, bytenr);
+       btrfs_set_header_generation(buf, 1);
+       btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
+       btrfs_set_header_owner(buf, owner);
+       btrfs_set_header_flags(buf, BTRFS_HEADER_FLAG_WRITTEN);
+       write_extent_buffer(buf, chunk_uuid, btrfs_header_chunk_tree_uuid(buf),
+                           BTRFS_UUID_SIZE);
+       write_extent_buffer(buf, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
+       return 0;
+}
+
+static inline int write_temp_extent_buffer(int fd, struct extent_buffer *buf,
+                                          u64 bytenr)
+{
+       int ret;
+
+       csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
+
+       /* Temporary extent buffer is always mapped 1:1 on disk */
+       ret = pwrite(fd, buf->data, buf->len, bytenr);
+       if (ret < buf->len)
+               ret = (ret < 0 ? ret : -EIO);
+       else
+               ret = 0;
+       return ret;
+}
+
+/*
+ * Insert a root item for temporary tree root
+ *
+ * Only used in make_btrfs_v2().
+ */
+static void insert_temp_root_item(struct extent_buffer *buf,
+                                 struct btrfs_mkfs_config *cfg,
+                                 int *slot, u32 *itemoff, u64 objectid,
+                                 u64 bytenr)
+{
+       struct btrfs_root_item root_item;
+       struct btrfs_inode_item *inode_item;
+       struct btrfs_disk_key disk_key;
+
+       btrfs_set_header_nritems(buf, *slot + 1);
+       (*itemoff) -= sizeof(root_item);
+       memset(&root_item, 0, sizeof(root_item));
+       inode_item = &root_item.inode;
+       btrfs_set_stack_inode_generation(inode_item, 1);
+       btrfs_set_stack_inode_size(inode_item, 3);
+       btrfs_set_stack_inode_nlink(inode_item, 1);
+       btrfs_set_stack_inode_nbytes(inode_item, cfg->nodesize);
+       btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
+       btrfs_set_root_refs(&root_item, 1);
+       btrfs_set_root_used(&root_item, cfg->nodesize);
+       btrfs_set_root_generation(&root_item, 1);
+       btrfs_set_root_bytenr(&root_item, bytenr);
+
+       memset(&disk_key, 0, sizeof(disk_key));
+       btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
+       btrfs_set_disk_key_objectid(&disk_key, objectid);
+       btrfs_set_disk_key_offset(&disk_key, 0);
+
+       btrfs_set_item_key(buf, &disk_key, *slot);
+       btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
+       btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(root_item));
+       write_extent_buffer(buf, &root_item,
+                           btrfs_item_ptr_offset(buf, *slot),
+                           sizeof(root_item));
+       (*slot)++;
+}
+
+static int setup_temp_root_tree(int fd, struct btrfs_mkfs_config *cfg,
+                               u64 root_bytenr, u64 extent_bytenr,
+                               u64 dev_bytenr, u64 fs_bytenr, u64 csum_bytenr)
+{
+       struct extent_buffer *buf = NULL;
+       u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
+       int slot = 0;
+       int ret;
+
+       /*
+        * Provided bytenr must in ascending order, or tree root will have a
+        * bad key order.
+        */
+       if (!(root_bytenr < extent_bytenr && extent_bytenr < dev_bytenr &&
+             dev_bytenr < fs_bytenr && fs_bytenr < csum_bytenr)) {
+               error("bad tree bytenr order: "
+                               "root < extent %llu < %llu, "
+                               "extent < dev %llu < %llu, "
+                               "dev < fs %llu < %llu, "
+                               "fs < csum %llu < %llu",
+                               (unsigned long long)root_bytenr,
+                               (unsigned long long)extent_bytenr,
+                               (unsigned long long)extent_bytenr,
+                               (unsigned long long)dev_bytenr,
+                               (unsigned long long)dev_bytenr,
+                               (unsigned long long)fs_bytenr,
+                               (unsigned long long)fs_bytenr,
+                               (unsigned long long)csum_bytenr);
+               return -EINVAL;
+       }
+       buf = malloc(sizeof(*buf) + cfg->nodesize);
+       if (!buf)
+               return -ENOMEM;
+
+       ret = setup_temp_extent_buffer(buf, cfg, root_bytenr,
+                                      BTRFS_ROOT_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+
+       insert_temp_root_item(buf, cfg, &slot, &itemoff,
+                             BTRFS_EXTENT_TREE_OBJECTID, extent_bytenr);
+       insert_temp_root_item(buf, cfg, &slot, &itemoff,
+                             BTRFS_DEV_TREE_OBJECTID, dev_bytenr);
+       insert_temp_root_item(buf, cfg, &slot, &itemoff,
+                             BTRFS_FS_TREE_OBJECTID, fs_bytenr);
+       insert_temp_root_item(buf, cfg, &slot, &itemoff,
+                             BTRFS_CSUM_TREE_OBJECTID, csum_bytenr);
+
+       ret = write_temp_extent_buffer(fd, buf, root_bytenr);
+out:
+       free(buf);
+       return ret;
+}
+
+static int insert_temp_dev_item(int fd, struct extent_buffer *buf,
+                               struct btrfs_mkfs_config *cfg,
+                               int *slot, u32 *itemoff)
+{
+       struct btrfs_disk_key disk_key;
+       struct btrfs_dev_item *dev_item;
+       char super_buf[BTRFS_SUPER_INFO_SIZE];
+       unsigned char dev_uuid[BTRFS_UUID_SIZE];
+       unsigned char fsid[BTRFS_FSID_SIZE];
+       struct btrfs_super_block *super = (struct btrfs_super_block *)super_buf;
+       int ret;
+
+       ret = pread(fd, super_buf, BTRFS_SUPER_INFO_SIZE, cfg->super_bytenr);
+       if (ret < BTRFS_SUPER_INFO_SIZE) {
+               ret = (ret < 0 ? -errno : -EIO);
+               goto out;
+       }
+
+       btrfs_set_header_nritems(buf, *slot + 1);
+       (*itemoff) -= sizeof(*dev_item);
+       /* setup device item 1, 0 is for replace case */
+       btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_ITEM_KEY);
+       btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_ITEMS_OBJECTID);
+       btrfs_set_disk_key_offset(&disk_key, 1);
+       btrfs_set_item_key(buf, &disk_key, *slot);
+       btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
+       btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(*dev_item));
+
+       dev_item = btrfs_item_ptr(buf, *slot, struct btrfs_dev_item);
+       /* Generate device uuid */
+       uuid_generate(dev_uuid);
+       write_extent_buffer(buf, dev_uuid,
+                       (unsigned long)btrfs_device_uuid(dev_item),
+                       BTRFS_UUID_SIZE);
+       uuid_parse(cfg->fs_uuid, fsid);
+       write_extent_buffer(buf, fsid,
+                       (unsigned long)btrfs_device_fsid(dev_item),
+                       BTRFS_FSID_SIZE);
+       btrfs_set_device_id(buf, dev_item, 1);
+       btrfs_set_device_generation(buf, dev_item, 0);
+       btrfs_set_device_total_bytes(buf, dev_item, cfg->num_bytes);
+       /*
+        * The number must match the initial SYSTEM and META chunk size
+        */
+       btrfs_set_device_bytes_used(buf, dev_item,
+                       BTRFS_MKFS_SYSTEM_GROUP_SIZE +
+                       BTRFS_CONVERT_META_GROUP_SIZE);
+       btrfs_set_device_io_align(buf, dev_item, cfg->sectorsize);
+       btrfs_set_device_io_width(buf, dev_item, cfg->sectorsize);
+       btrfs_set_device_sector_size(buf, dev_item, cfg->sectorsize);
+       btrfs_set_device_type(buf, dev_item, 0);
+
+       /* Super dev_item is not complete, copy the complete one to sb */
+       read_extent_buffer(buf, &super->dev_item, (unsigned long)dev_item,
+                          sizeof(*dev_item));
+       ret = write_temp_super(fd, super, cfg->super_bytenr);
+       (*slot)++;
+out:
+       return ret;
+}
+
+static int insert_temp_chunk_item(int fd, struct extent_buffer *buf,
+                                 struct btrfs_mkfs_config *cfg,
+                                 int *slot, u32 *itemoff, u64 start, u64 len,
+                                 u64 type)
+{
+       struct btrfs_chunk *chunk;
+       struct btrfs_disk_key disk_key;
+       char super_buf[BTRFS_SUPER_INFO_SIZE];
+       struct btrfs_super_block *sb = (struct btrfs_super_block *)super_buf;
+       int ret = 0;
+
+       ret = pread(fd, super_buf, BTRFS_SUPER_INFO_SIZE,
+                   cfg->super_bytenr);
+       if (ret < BTRFS_SUPER_INFO_SIZE) {
+               ret = (ret < 0 ? ret : -EIO);
+               return ret;
+       }
+
+       btrfs_set_header_nritems(buf, *slot + 1);
+       (*itemoff) -= btrfs_chunk_item_size(1);
+       btrfs_set_disk_key_type(&disk_key, BTRFS_CHUNK_ITEM_KEY);
+       btrfs_set_disk_key_objectid(&disk_key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+       btrfs_set_disk_key_offset(&disk_key, start);
+       btrfs_set_item_key(buf, &disk_key, *slot);
+       btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
+       btrfs_set_item_size(buf, btrfs_item_nr(*slot),
+                           btrfs_chunk_item_size(1));
+
+       chunk = btrfs_item_ptr(buf, *slot, struct btrfs_chunk);
+       btrfs_set_chunk_length(buf, chunk, len);
+       btrfs_set_chunk_owner(buf, chunk, BTRFS_EXTENT_TREE_OBJECTID);
+       btrfs_set_chunk_stripe_len(buf, chunk, 64 * 1024);
+       btrfs_set_chunk_type(buf, chunk, type);
+       btrfs_set_chunk_io_align(buf, chunk, cfg->sectorsize);
+       btrfs_set_chunk_io_width(buf, chunk, cfg->sectorsize);
+       btrfs_set_chunk_sector_size(buf, chunk, cfg->sectorsize);
+       btrfs_set_chunk_num_stripes(buf, chunk, 1);
+       /* TODO: Support DUP profile for system chunk */
+       btrfs_set_stripe_devid_nr(buf, chunk, 0, 1);
+       /* We are doing 1:1 mapping, so start is its dev offset */
+       btrfs_set_stripe_offset_nr(buf, chunk, 0, start);
+       write_extent_buffer(buf, &sb->dev_item.uuid,
+                           (unsigned long)btrfs_stripe_dev_uuid_nr(chunk, 0),
+                           BTRFS_UUID_SIZE);
+       (*slot)++;
+
+       /*
+        * If it's system chunk, also copy it to super block.
+        */
+       if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
+               char *cur;
+
+               cur = (char *)sb->sys_chunk_array + sb->sys_chunk_array_size;
+               memcpy(cur, &disk_key, sizeof(disk_key));
+               cur += sizeof(disk_key);
+               read_extent_buffer(buf, cur, (unsigned long int)chunk,
+                                  btrfs_chunk_item_size(1));
+               sb->sys_chunk_array_size += btrfs_chunk_item_size(1) +
+                                           sizeof(disk_key);
+
+               ret = write_temp_super(fd, sb, cfg->super_bytenr);
+       }
+       return ret;
+}
+
+static int setup_temp_chunk_tree(int fd, struct btrfs_mkfs_config *cfg,
+                                u64 sys_chunk_start, u64 meta_chunk_start,
+                                u64 chunk_bytenr)
+{
+       struct extent_buffer *buf = NULL;
+       u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
+       int slot = 0;
+       int ret;
+
+       /* Must ensure SYS chunk starts before META chunk */
+       if (meta_chunk_start < sys_chunk_start) {
+               error("wrong chunk order: meta < system %llu < %llu",
+                               (unsigned long long)meta_chunk_start,
+                               (unsigned long long)sys_chunk_start);
+               return -EINVAL;
+       }
+       buf = malloc(sizeof(*buf) + cfg->nodesize);
+       if (!buf)
+               return -ENOMEM;
+       ret = setup_temp_extent_buffer(buf, cfg, chunk_bytenr,
+                                      BTRFS_CHUNK_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+
+       ret = insert_temp_dev_item(fd, buf, cfg, &slot, &itemoff);
+       if (ret < 0)
+               goto out;
+       ret = insert_temp_chunk_item(fd, buf, cfg, &slot, &itemoff,
+                                    sys_chunk_start,
+                                    BTRFS_MKFS_SYSTEM_GROUP_SIZE,
+                                    BTRFS_BLOCK_GROUP_SYSTEM);
+       if (ret < 0)
+               goto out;
+       ret = insert_temp_chunk_item(fd, buf, cfg, &slot, &itemoff,
+                                    meta_chunk_start,
+                                    BTRFS_CONVERT_META_GROUP_SIZE,
+                                    BTRFS_BLOCK_GROUP_METADATA);
+       if (ret < 0)
+               goto out;
+       ret = write_temp_extent_buffer(fd, buf, chunk_bytenr);
+
+out:
+       free(buf);
+       return ret;
+}
+
+static void insert_temp_dev_extent(struct extent_buffer *buf,
+                                  int *slot, u32 *itemoff, u64 start, u64 len)
+{
+       struct btrfs_dev_extent *dev_extent;
+       struct btrfs_disk_key disk_key;
+
+       btrfs_set_header_nritems(buf, *slot + 1);
+       (*itemoff) -= sizeof(*dev_extent);
+       btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_EXTENT_KEY);
+       btrfs_set_disk_key_objectid(&disk_key, 1);
+       btrfs_set_disk_key_offset(&disk_key, start);
+       btrfs_set_item_key(buf, &disk_key, *slot);
+       btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
+       btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(*dev_extent));
+
+       dev_extent = btrfs_item_ptr(buf, *slot, struct btrfs_dev_extent);
+       btrfs_set_dev_extent_chunk_objectid(buf, dev_extent,
+                                           BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+       btrfs_set_dev_extent_length(buf, dev_extent, len);
+       btrfs_set_dev_extent_chunk_offset(buf, dev_extent, start);
+       btrfs_set_dev_extent_chunk_tree(buf, dev_extent,
+                                       BTRFS_CHUNK_TREE_OBJECTID);
+       (*slot)++;
+}
+
+static int setup_temp_dev_tree(int fd, struct btrfs_mkfs_config *cfg,
+                              u64 sys_chunk_start, u64 meta_chunk_start,
+                              u64 dev_bytenr)
+{
+       struct extent_buffer *buf = NULL;
+       u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
+       int slot = 0;
+       int ret;
+
+       /* Must ensure SYS chunk starts before META chunk */
+       if (meta_chunk_start < sys_chunk_start) {
+               error("wrong chunk order: meta < system %llu < %llu",
+                               (unsigned long long)meta_chunk_start,
+                               (unsigned long long)sys_chunk_start);
+               return -EINVAL;
+       }
+       buf = malloc(sizeof(*buf) + cfg->nodesize);
+       if (!buf)
+               return -ENOMEM;
+       ret = setup_temp_extent_buffer(buf, cfg, dev_bytenr,
+                                      BTRFS_DEV_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+       insert_temp_dev_extent(buf, &slot, &itemoff, sys_chunk_start,
+                              BTRFS_MKFS_SYSTEM_GROUP_SIZE);
+       insert_temp_dev_extent(buf, &slot, &itemoff, meta_chunk_start,
+                              BTRFS_CONVERT_META_GROUP_SIZE);
+       ret = write_temp_extent_buffer(fd, buf, dev_bytenr);
+out:
+       free(buf);
+       return ret;
+}
+
+static int setup_temp_fs_tree(int fd, struct btrfs_mkfs_config *cfg,
+                             u64 fs_bytenr)
+{
+       struct extent_buffer *buf = NULL;
+       int ret;
+
+       buf = malloc(sizeof(*buf) + cfg->nodesize);
+       if (!buf)
+               return -ENOMEM;
+       ret = setup_temp_extent_buffer(buf, cfg, fs_bytenr,
+                                      BTRFS_FS_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+       /*
+        * Temporary fs tree is completely empty.
+        */
+       ret = write_temp_extent_buffer(fd, buf, fs_bytenr);
+out:
+       free(buf);
+       return ret;
+}
+
+static int setup_temp_csum_tree(int fd, struct btrfs_mkfs_config *cfg,
+                               u64 csum_bytenr)
+{
+       struct extent_buffer *buf = NULL;
+       int ret;
+
+       buf = malloc(sizeof(*buf) + cfg->nodesize);
+       if (!buf)
+               return -ENOMEM;
+       ret = setup_temp_extent_buffer(buf, cfg, csum_bytenr,
+                                      BTRFS_CSUM_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+       /*
+        * Temporary csum tree is completely empty.
+        */
+       ret = write_temp_extent_buffer(fd, buf, csum_bytenr);
+out:
+       free(buf);
+       return ret;
+}
+
+/*
+ * Insert one temporary extent item.
+ *
+ * NOTE: if skinny_metadata is not enabled, this function must be called
+ * after all other trees are initialized.
+ * Or fs without skinny-metadata will be screwed up.
+ */
+static int insert_temp_extent_item(int fd, struct extent_buffer *buf,
+                                  struct btrfs_mkfs_config *cfg,
+                                  int *slot, u32 *itemoff, u64 bytenr,
+                                  u64 ref_root)
+{
+       struct extent_buffer *tmp;
+       struct btrfs_extent_item *ei;
+       struct btrfs_extent_inline_ref *iref;
+       struct btrfs_disk_key disk_key;
+       struct btrfs_disk_key tree_info_key;
+       struct btrfs_tree_block_info *info;
+       int itemsize;
+       int skinny_metadata = cfg->features &
+                             BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
+       int ret;
+
+       if (skinny_metadata)
+               itemsize = sizeof(*ei) + sizeof(*iref);
+       else
+               itemsize = sizeof(*ei) + sizeof(*iref) +
+                          sizeof(struct btrfs_tree_block_info);
+
+       btrfs_set_header_nritems(buf, *slot + 1);
+       *(itemoff) -= itemsize;
+
+       if (skinny_metadata) {
+               btrfs_set_disk_key_type(&disk_key, BTRFS_METADATA_ITEM_KEY);
+               btrfs_set_disk_key_offset(&disk_key, 0);
+       } else {
+               btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
+               btrfs_set_disk_key_offset(&disk_key, cfg->nodesize);
+       }
+       btrfs_set_disk_key_objectid(&disk_key, bytenr);
+
+       btrfs_set_item_key(buf, &disk_key, *slot);
+       btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
+       btrfs_set_item_size(buf, btrfs_item_nr(*slot), itemsize);
+
+       ei = btrfs_item_ptr(buf, *slot, struct btrfs_extent_item);
+       btrfs_set_extent_refs(buf, ei, 1);
+       btrfs_set_extent_generation(buf, ei, 1);
+       btrfs_set_extent_flags(buf, ei, BTRFS_EXTENT_FLAG_TREE_BLOCK);
+
+       if (skinny_metadata) {
+               iref = (struct btrfs_extent_inline_ref *)(ei + 1);
+       } else {
+               info = (struct btrfs_tree_block_info *)(ei + 1);
+               iref = (struct btrfs_extent_inline_ref *)(info + 1);
+       }
+       btrfs_set_extent_inline_ref_type(buf, iref,
+                                        BTRFS_TREE_BLOCK_REF_KEY);
+       btrfs_set_extent_inline_ref_offset(buf, iref, ref_root);
+
+       (*slot)++;
+       if (skinny_metadata)
+               return 0;
+
+       /*
+        * Lastly, check the tree block key by read the tree block
+        * Since we do 1:1 mapping for convert case, we can directly
+        * read the bytenr from disk
+        */
+       tmp = malloc(sizeof(*tmp) + cfg->nodesize);
+       if (!tmp)
+               return -ENOMEM;
+       ret = setup_temp_extent_buffer(tmp, cfg, bytenr, ref_root);
+       if (ret < 0)
+               goto out;
+       ret = pread(fd, tmp->data, cfg->nodesize, bytenr);
+       if (ret < cfg->nodesize) {
+               ret = (ret < 0 ? -errno : -EIO);
+               goto out;
+       }
+       if (btrfs_header_nritems(tmp) == 0) {
+               btrfs_set_disk_key_type(&tree_info_key, 0);
+               btrfs_set_disk_key_objectid(&tree_info_key, 0);
+               btrfs_set_disk_key_offset(&tree_info_key, 0);
+       } else {
+               btrfs_item_key(tmp, &tree_info_key, 0);
+       }
+       btrfs_set_tree_block_key(buf, info, &tree_info_key);
+
+out:
+       free(tmp);
+       return ret;
+}
+
+static void insert_temp_block_group(struct extent_buffer *buf,
+                                  struct btrfs_mkfs_config *cfg,
+                                  int *slot, u32 *itemoff,
+                                  u64 bytenr, u64 len, u64 used, u64 flag)
+{
+       struct btrfs_block_group_item bgi;
+       struct btrfs_disk_key disk_key;
+
+       btrfs_set_header_nritems(buf, *slot + 1);
+       (*itemoff) -= sizeof(bgi);
+       btrfs_set_disk_key_type(&disk_key, BTRFS_BLOCK_GROUP_ITEM_KEY);
+       btrfs_set_disk_key_objectid(&disk_key, bytenr);
+       btrfs_set_disk_key_offset(&disk_key, len);
+       btrfs_set_item_key(buf, &disk_key, *slot);
+       btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
+       btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(bgi));
+
+       btrfs_set_block_group_flags(&bgi, flag);
+       btrfs_set_block_group_used(&bgi, used);
+       btrfs_set_block_group_chunk_objectid(&bgi,
+                       BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+       write_extent_buffer(buf, &bgi, btrfs_item_ptr_offset(buf, *slot),
+                           sizeof(bgi));
+       (*slot)++;
+}
+
+static int setup_temp_extent_tree(int fd, struct btrfs_mkfs_config *cfg,
+                                 u64 chunk_bytenr, u64 root_bytenr,
+                                 u64 extent_bytenr, u64 dev_bytenr,
+                                 u64 fs_bytenr, u64 csum_bytenr)
+{
+       struct extent_buffer *buf = NULL;
+       u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
+       int slot = 0;
+       int ret;
+
+       /*
+        * We must ensure provided bytenr are in ascending order,
+        * or extent tree key order will be broken.
+        */
+       if (!(chunk_bytenr < root_bytenr && root_bytenr < extent_bytenr &&
+             extent_bytenr < dev_bytenr && dev_bytenr < fs_bytenr &&
+             fs_bytenr < csum_bytenr)) {
+               error("bad tree bytenr order: "
+                               "chunk < root %llu < %llu, "
+                               "root < extent %llu < %llu, "
+                               "extent < dev %llu < %llu, "
+                               "dev < fs %llu < %llu, "
+                               "fs < csum %llu < %llu",
+                               (unsigned long long)chunk_bytenr,
+                               (unsigned long long)root_bytenr,
+                               (unsigned long long)root_bytenr,
+                               (unsigned long long)extent_bytenr,
+                               (unsigned long long)extent_bytenr,
+                               (unsigned long long)dev_bytenr,
+                               (unsigned long long)dev_bytenr,
+                               (unsigned long long)fs_bytenr,
+                               (unsigned long long)fs_bytenr,
+                               (unsigned long long)csum_bytenr);
+               return -EINVAL;
+       }
+       buf = malloc(sizeof(*buf) + cfg->nodesize);
+       if (!buf)
+               return -ENOMEM;
+
+       ret = setup_temp_extent_buffer(buf, cfg, extent_bytenr,
+                                      BTRFS_EXTENT_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+
+       ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
+                       chunk_bytenr, BTRFS_CHUNK_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+
+       insert_temp_block_group(buf, cfg, &slot, &itemoff, chunk_bytenr,
+                       BTRFS_MKFS_SYSTEM_GROUP_SIZE, cfg->nodesize,
+                       BTRFS_BLOCK_GROUP_SYSTEM);
+
+       ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
+                       root_bytenr, BTRFS_ROOT_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+
+       /* 5 tree block used, root, extent, dev, fs and csum*/
+       insert_temp_block_group(buf, cfg, &slot, &itemoff, root_bytenr,
+                       BTRFS_CONVERT_META_GROUP_SIZE, cfg->nodesize * 5,
+                       BTRFS_BLOCK_GROUP_METADATA);
+
+       ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
+                       extent_bytenr, BTRFS_EXTENT_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+       ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
+                       dev_bytenr, BTRFS_DEV_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+       ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
+                       fs_bytenr, BTRFS_FS_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+       ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
+                       csum_bytenr, BTRFS_CSUM_TREE_OBJECTID);
+       if (ret < 0)
+               goto out;
+
+       ret = write_temp_extent_buffer(fd, buf, extent_bytenr);
+out:
+       free(buf);
+       return ret;
+}
+
+/*
+ * Improved version of make_btrfs().
+ *
+ * This one will
+ * 1) Do chunk allocation to avoid used data
+ *    And after this function, extent type matches chunk type
+ * 2) Better structured code
+ *    No super long hand written codes to initialized all tree blocks
+ *    Split into small blocks and reuse codes.
+ *    TODO: Reuse tree operation facilities by introducing new flags
+ */
+static int make_convert_btrfs(int fd, struct btrfs_mkfs_config *cfg,
+                             struct btrfs_convert_context *cctx)
+{
+       struct cache_tree *free = &cctx->free;
+       struct cache_tree *used = &cctx->used;
+       u64 sys_chunk_start;
+       u64 meta_chunk_start;
+       /* chunk tree bytenr, in system chunk */
+       u64 chunk_bytenr;
+       /* metadata trees bytenr, in metadata chunk */
+       u64 root_bytenr;
+       u64 extent_bytenr;
+       u64 dev_bytenr;
+       u64 fs_bytenr;
+       u64 csum_bytenr;
+       int ret;
+
+       /* Shouldn't happen */
+       BUG_ON(cache_tree_empty(used));
+
+       /*
+        * reserve space for temporary superblock first
+        * Here we allocate a little larger space, to keep later
+        * free space will be STRIPE_LEN aligned
+        */
+       ret = reserve_free_space(free, BTRFS_STRIPE_LEN,
+                                &cfg->super_bytenr);
+       if (ret < 0)
+               goto out;
+
+       /*
+        * Then reserve system chunk space
+        * TODO: Change system group size depending on cctx->total_bytes.
+        * If using current 4M, it can only handle less than one TB for
+        * worst case and then run out of sys space.
+        */
+       ret = reserve_free_space(free, BTRFS_MKFS_SYSTEM_GROUP_SIZE,
+                                &sys_chunk_start);
+       if (ret < 0)
+               goto out;
+       ret = reserve_free_space(free, BTRFS_CONVERT_META_GROUP_SIZE,
+                                &meta_chunk_start);
+       if (ret < 0)
+               goto out;
+
+       /*
+        * Allocated meta/sys chunks will be mapped 1:1 with device offset.
+        *
+        * Inside the allocated metadata chunk, the layout will be:
+        *  | offset            | contents      |
+        *  -------------------------------------
+        *  | +0                | tree root     |
+        *  | +nodesize         | extent root   |
+        *  | +nodesize * 2     | device root   |
+        *  | +nodesize * 3     | fs tree       |
+        *  | +nodesize * 4     | csum tree     |
+        *  -------------------------------------
+        * Inside the allocated system chunk, the layout will be:
+        *  | offset            | contents      |
+        *  -------------------------------------
+        *  | +0                | chunk root    |
+        *  -------------------------------------
+        */
+       chunk_bytenr = sys_chunk_start;
+       root_bytenr = meta_chunk_start;
+       extent_bytenr = meta_chunk_start + cfg->nodesize;
+       dev_bytenr = meta_chunk_start + cfg->nodesize * 2;
+       fs_bytenr = meta_chunk_start + cfg->nodesize * 3;
+       csum_bytenr = meta_chunk_start + cfg->nodesize * 4;
+
+       ret = setup_temp_super(fd, cfg, root_bytenr, chunk_bytenr);
+       if (ret < 0)
+               goto out;
+
+       ret = setup_temp_root_tree(fd, cfg, root_bytenr, extent_bytenr,
+                                  dev_bytenr, fs_bytenr, csum_bytenr);
+       if (ret < 0)
+               goto out;
+       ret = setup_temp_chunk_tree(fd, cfg, sys_chunk_start, meta_chunk_start,
+                                   chunk_bytenr);
+       if (ret < 0)
+               goto out;
+       ret = setup_temp_dev_tree(fd, cfg, sys_chunk_start, meta_chunk_start,
+                                 dev_bytenr);
+       if (ret < 0)
+               goto out;
+       ret = setup_temp_fs_tree(fd, cfg, fs_bytenr);
+       if (ret < 0)
+               goto out;
+       ret = setup_temp_csum_tree(fd, cfg, csum_bytenr);
+       if (ret < 0)
+               goto out;
+       /*
+        * Setup extent tree last, since it may need to read tree block key
+        * for non-skinny metadata case.
+        */
+       ret = setup_temp_extent_tree(fd, cfg, chunk_bytenr, root_bytenr,
+                                    extent_bytenr, dev_bytenr, fs_bytenr,
+                                    csum_bytenr);
+out:
+       return ret;
+}
+
+/*
  * @fs_uuid - if NULL, generates a UUID, returns back the new filesystem UUID
+ *
+ * The superblock signature is not valid, denotes a partially created
+ * filesystem, needs to be finalized.
  */
-int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
+int make_btrfs(int fd, struct btrfs_mkfs_config *cfg,
+               struct btrfs_convert_context *cctx)
 {
        struct btrfs_super_block super;
        struct extent_buffer *buf;
@@ -209,6 +1072,8 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
                                 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
        u64 num_bytes;
 
+       if (cctx)
+               return make_convert_btrfs(fd, cfg, cctx);
        buf = malloc(sizeof(*buf) + max(cfg->sectorsize, cfg->nodesize));
        if (!buf)
                return -ENOMEM;
@@ -219,7 +1084,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
        memset(&super, 0, sizeof(super));
 
        num_bytes = (cfg->num_bytes / cfg->sectorsize) * cfg->sectorsize;
-       if (cfg->fs_uuid && *cfg->fs_uuid) {
+       if (*cfg->fs_uuid) {
                if (uuid_parse(cfg->fs_uuid, super.fsid) != 0) {
                        error("cannot not parse UUID: %s", cfg->fs_uuid);
                        ret = -EINVAL;
@@ -240,7 +1105,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 
        btrfs_set_super_bytenr(&super, cfg->blocks[0]);
        btrfs_set_super_num_devices(&super, 1);
-       btrfs_set_super_magic(&super, BTRFS_MAGIC);
+       btrfs_set_super_magic(&super, BTRFS_MAGIC_PARTIAL);
        btrfs_set_super_generation(&super, 1);
        btrfs_set_super_root(&super, cfg->blocks[1]);
        btrfs_set_super_chunk_root(&super, cfg->blocks[3]);
@@ -354,8 +1219,21 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
                if (!skinny_metadata)
                        item_size += sizeof(struct btrfs_tree_block_info);
 
-               BUG_ON(cfg->blocks[i] < first_free);
-               BUG_ON(cfg->blocks[i] < cfg->blocks[i - 1]);
+               if (cfg->blocks[i] < first_free) {
+                       error("block[%d] below first free: %llu < %llu",
+                                       i, (unsigned long long)cfg->blocks[i],
+                                       (unsigned long long)first_free);
+                       ret = -EINVAL;
+                       goto out;
+               }
+               if (cfg->blocks[i] < cfg->blocks[i - 1]) {
+                       error("blocks %d and %d in reverse order: %llu < %llu",
+                               i, i - 1,
+                               (unsigned long long)cfg->blocks[i],
+                               (unsigned long long)cfg->blocks[i - 1]);
+                       ret = -EINVAL;
+                       goto out;
+               }
 
                /* create extent item */
                itemoff -= item_size;
@@ -555,7 +1433,6 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
        }
 
        /* and write out the super block */
-       BUG_ON(sizeof(super) > cfg->sectorsize);
        memset(buf->data, 0, BTRFS_SUPER_INFO_SIZE);
        memcpy(buf->data, &super, sizeof(super));
        buf->len = BTRFS_SUPER_INFO_SIZE;
@@ -729,7 +1606,7 @@ static int zero_dev_clamped(int fd, off_t start, ssize_t len, u64 dev_size)
 }
 
 int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
-                     struct btrfs_root *root, int fd, char *path,
+                     struct btrfs_root *root, int fd, const char *path,
                      u64 device_total_bytes, u32 io_width, u32 io_align,
                      u32 sectorsize)
 {
@@ -744,13 +1621,16 @@ int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
 
        device_total_bytes = (device_total_bytes / sectorsize) * sectorsize;
 
-       device = kzalloc(sizeof(*device), GFP_NOFS);
-       if (!device)
-               goto err_nomem;
-       buf = kzalloc(sectorsize, GFP_NOFS);
-       if (!buf)
-               goto err_nomem;
-       BUG_ON(sizeof(*disk_super) > sectorsize);
+       device = calloc(1, sizeof(*device));
+       if (!device) {
+               ret = -ENOMEM;
+               goto out;
+       }
+       buf = calloc(1, sectorsize);
+       if (!buf) {
+               ret = -ENOMEM;
+               goto out;
+       }
 
        disk_super = (struct btrfs_super_block *)buf;
        dev_item = &disk_super->dev_item;
@@ -768,12 +1648,15 @@ int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
        device->total_ios = 0;
        device->dev_root = root->fs_info->dev_root;
        device->name = strdup(path);
-       if (!device->name)
-               goto err_nomem;
+       if (!device->name) {
+               ret = -ENOMEM;
+               goto out;
+       }
 
        INIT_LIST_HEAD(&device->dev_list);
        ret = btrfs_add_device(trans, root, device);
-       BUG_ON(ret);
+       if (ret)
+               goto out;
 
        fs_total_bytes = btrfs_super_total_bytes(super) + device_total_bytes;
        btrfs_set_super_total_bytes(super, fs_total_bytes);
@@ -796,15 +1679,15 @@ int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
        ret = pwrite(fd, buf, sectorsize, BTRFS_SUPER_INFO_OFFSET);
        BUG_ON(ret != sectorsize);
 
-       kfree(buf);
+       free(buf);
        list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
        device->fs_devices = root->fs_info->fs_devices;
        return 0;
 
-err_nomem:
-       kfree(device);
-       kfree(buf);
-       return -ENOMEM;
+out:
+       free(device);
+       free(buf);
+       return ret;
 }
 
 static int btrfs_wipe_existing_sb(int fd)
@@ -858,8 +1741,8 @@ out:
        return ret;
 }
 
-int btrfs_prepare_device(int fd, const char *file, int zero_end,
-               u64 *block_count_ret, u64 max_block_count, int discard)
+int btrfs_prepare_device(int fd, const char *file, u64 *block_count_ret,
+               u64 max_block_count, unsigned opflags)
 {
        u64 block_count;
        struct stat st;
@@ -879,15 +1762,16 @@ int btrfs_prepare_device(int fd, const char *file, int zero_end,
        if (max_block_count)
                block_count = min(block_count, max_block_count);
 
-       if (discard) {
+       if (opflags & PREP_DEVICE_DISCARD) {
                /*
                 * We intentionally ignore errors from the discard ioctl.  It
                 * is not necessary for the mkfs functionality but just an
                 * optimization.
                 */
                if (discard_range(fd, 0, 0) == 0) {
-                       printf("Performing full device TRIM (%s) ...\n",
-                               pretty_size(block_count));
+                       if (opflags & PREP_DEVICE_VERBOSE)
+                               printf("Performing full device TRIM (%s) ...\n",
+                                               pretty_size(block_count));
                        discard_blocks(fd, 0, block_count);
                }
        }
@@ -896,7 +1780,7 @@ int btrfs_prepare_device(int fd, const char *file, int zero_end,
        for (i = 0 ; !ret && i < BTRFS_SUPER_MIRROR_MAX; i++)
                ret = zero_dev_clamped(fd, btrfs_sb_offset(i),
                                       BTRFS_SUPER_INFO_SIZE, block_count);
-       if (!ret && zero_end)
+       if (!ret && (opflags & PREP_DEVICE_ZERO_END))
                ret = zero_dev_clamped(fd, block_count - ZERO_DEV_BYTES,
                                       ZERO_DEV_BYTES, block_count);
 
@@ -1447,7 +2331,7 @@ int check_mounted_where(int fd, const char *file, char *where, int size,
 
        /* scan the initial device */
        ret = btrfs_scan_one_device(fd, file, &fs_devices_mnt,
-                                   &total_devs, BTRFS_SUPER_INFO_OFFSET, 0);
+                   &total_devs, BTRFS_SUPER_INFO_OFFSET, SBREAD_DEFAULT);
        is_btrfs = (ret >= 0);
 
        /* scan other devices */
@@ -1575,7 +2459,12 @@ int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
 
        ret = 0;
        disk_super = (struct btrfs_super_block *)buf;
-       if (btrfs_super_magic(disk_super) != BTRFS_MAGIC)
+       /*
+        * Accept devices from the same filesystem, allow partially created
+        * structures.
+        */
+       if (btrfs_super_magic(disk_super) != BTRFS_MAGIC &&
+                       btrfs_super_magic(disk_super) != BTRFS_MAGIC_PARTIAL)
                goto brelse;
 
        if (!memcmp(disk_super->fsid, root->fs_info->super_copy->fsid,
@@ -1991,6 +2880,8 @@ path:
        if (fd < 0)
                goto err;
        ret = lookup_ino_rootid(fd, &id);
+       if (ret)
+               error("failed to lookup root id: %s", strerror(-ret));
        close(fd);
        if (ret < 0)
                goto err;
@@ -2140,7 +3031,7 @@ again:
  *
  * Returns 0 on success, or a negative errno.
  */
-int get_fs_info(char *path, struct btrfs_ioctl_fs_info_args *fi_args,
+int get_fs_info(const char *path, struct btrfs_ioctl_fs_info_args *fi_args,
                struct btrfs_ioctl_dev_info_args **di_ret)
 {
        int fd = -1;
@@ -2442,6 +3333,7 @@ int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
        u64 dev_cnt, int mixed, int ssd)
 {
        u64 allowed = 0;
+       u64 profile = metadata_profile | data_profile;
 
        switch (dev_cnt) {
        default:
@@ -2456,8 +3348,7 @@ int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
                allowed |= BTRFS_BLOCK_GROUP_DUP;
        }
 
-       if (dev_cnt > 1 &&
-           ((metadata_profile | data_profile) & BTRFS_BLOCK_GROUP_DUP)) {
+       if (dev_cnt > 1 && profile & BTRFS_BLOCK_GROUP_DUP) {
                warning("DUP is not recommended on filesystem with multiple devices");
        }
        if (metadata_profile & ~allowed) {
@@ -2477,6 +3368,12 @@ int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
                return 1;
        }
 
+       if (dev_cnt == 3 && profile & BTRFS_BLOCK_GROUP_RAID6) {
+               warning("RAID6 is not recommended on filesystem with 3 devices only");
+       }
+       if (dev_cnt == 2 && profile & BTRFS_BLOCK_GROUP_RAID5) {
+               warning("RAID5 is not recommended on filesystem with 2 devices only");
+       }
        warning_on(!mixed && (data_profile & BTRFS_BLOCK_GROUP_DUP) && ssd,
                   "DUP may not actually lead to 2 copies on the device, see manual page");
 
@@ -2592,7 +3489,8 @@ int btrfs_scan_lblkid(void)
                        continue;
                }
                ret = btrfs_scan_one_device(fd, path, &tmp_devices,
-                               &num_devices, BTRFS_SUPER_INFO_OFFSET, 0);
+                               &num_devices, BTRFS_SUPER_INFO_OFFSET,
+                               SBREAD_DEFAULT);
                if (ret) {
                        error("cannot scan %s: %s", path, strerror(-ret));
                        close (fd);
@@ -2673,10 +3571,8 @@ int lookup_ino_rootid(int fd, u64 *rootid)
        args.objectid = BTRFS_FIRST_FREE_OBJECTID;
 
        ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
-       if (ret < 0) {
-               error("failed to lookup root id: %s", strerror(errno));
-               return ret;
-       }
+       if (ret < 0)
+               return -errno;
 
        *rootid = args.treeid;
 
@@ -3106,6 +4002,24 @@ void clean_args_no_options(int argc, char *argv[], const char * const *usagestr)
        }
 }
 
+/*
+ * Same as clean_args_no_options but pass through arguments that could look
+ * like short options. Eg. reisze which takes a negative resize argument like
+ * '-123M' .
+ *
+ * This accepts only two forms:
+ * - "-- option1 option2 ..."
+ * - "option1 option2 ..."
+ */
+void clean_args_no_options_relaxed(int argc, char *argv[], const char * const *usagestr)
+{
+       if (argc <= 1)
+               return;
+
+       if (strcmp(argv[1], "--") == 0)
+               optind = 2;
+}
+
 /* Subvolume helper functions */
 /*
  * test if name is a correct subvolume name