Introduce a new function, setup_temp_super(), to setup temporary super
for make_btrfs_v2().
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
Signed-off-by: David Sterba <dste...@suse.com>
---
utils.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 117 insertions(+)
diff --git a/utils.c b/utils.c
index bc10293..ed5476d 100644
--- a/utils.c
+++ b/utils.c
@@ -212,6 +212,98 @@ static int reserve_free_space(struct cache_tree
*free_tree, u64 len,
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, (char *)&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.
+ */
+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;
+
+ /*
+ * We rely on cfg->chunk_uuid and cfg->fs_uuid to pass uuid
+ * for other functions.
+ * Caller must allocation space for them
+ */
+ BUG_ON(!cfg->chunk_uuid || !cfg->fs_uuid);
+ memset(super_buf, 0, BTRFS_SUPER_INFO_SIZE);
+ cfg->num_bytes = round_down(cfg->num_bytes, cfg->sectorsize);
+
+ if (cfg->fs_uuid && *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);
+ 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 btrfs will only has 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(super->label, cfg->label, BTRFS_LABEL_SIZE - 1);
