btrfs-progs: Add new feature to mkfs.btrfs to make file system image file from source directory

Changes from V1 to V2:
- support extended attributes
- move btrfs_alloc_data_chunk function to volumes.c
- fix an execution error when additional useless parameters are specified
- fix traverse_directory function so that the insertion functions for the common items are invoked in a single point

The extended attributes is implemented through llistxattr and getxattr function calls.

Thanks

Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

mkfs.c

@@ -29,12 +29,14 @@
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/dir.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <getopt.h>
 #include <uuid/uuid.h>
 #include <linux/fs.h>
 #include <ctype.h>
+#include <attr/xattr.h>
 #include "kerncompat.h"
 #include "ctree.h"
 #include "disk-io.h"
@@ -43,6 +45,15 @@
 #include "utils.h"
 #include "version.h"
 
+static u64 index_cnt = 2;
+
+struct directory_name_entry {
+	char *dir_name;
+	char *path;
+	ino_t inum;
+	struct list_head list;
+};
+
 static u64 parse_size(char *s)
 {
 	int len = strlen(s);
@@ -298,6 +309,7 @@ static void print_usage(void)
 	fprintf(stderr, "\t -M --mixed mix metadata and data together\n");
 	fprintf(stderr, "\t -n --nodesize size of btree nodes\n");
 	fprintf(stderr, "\t -s --sectorsize min block allocation\n");
+	fprintf(stderr, "\t -r --rootdir the source directory\n");
 	fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);
 	exit(1);
 }
@@ -355,9 +367,768 @@ static struct option long_options[] = {
 	{ "sectorsize", 1, NULL, 's' },
 	{ "data", 1, NULL, 'd' },
 	{ "version", 0, NULL, 'V' },
+	{ "rootdir", 1, NULL, 'r' },
 	{ 0, 0, 0, 0}
 };
 
+static int add_directory_items(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root, u64 objectid,
+			       ino_t parent_inum, const char *name,
+			       struct stat *st, int *dir_index_cnt)
+{
+	int ret;
+	int name_len;
+	struct btrfs_key location;
+	u8 filetype = 0;
+
+	name_len = strlen(name);
+
+	location.objectid = objectid;
+	location.offset = 0;
+	btrfs_set_key_type(&location, BTRFS_INODE_ITEM_KEY);
+
+	if (S_ISDIR(st->st_mode))
+		filetype = BTRFS_FT_DIR;
+	if (S_ISREG(st->st_mode))
+		filetype = BTRFS_FT_REG_FILE;
+	if (S_ISLNK(st->st_mode))
+		filetype = BTRFS_FT_SYMLINK;
+
+	ret = btrfs_insert_dir_item(trans, root, name, name_len,
+				    parent_inum, &location,
+				    filetype, index_cnt);
+
+	*dir_index_cnt = index_cnt;
+	index_cnt++;
+
+	return ret;
+}
+
+static int fill_inode_item(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root,
+			   struct btrfs_inode_item *dst, struct stat *src)
+{
+	u64 blocks = 0;
+	u64 sectorsize = root->sectorsize;
+
+	btrfs_set_stack_inode_generation(dst, trans->transid);
+	btrfs_set_stack_inode_size(dst, src->st_size);
+	btrfs_set_stack_inode_nbytes(dst, 0);
+	btrfs_set_stack_inode_block_group(dst, 0);
+	btrfs_set_stack_inode_nlink(dst, src->st_nlink);
+	btrfs_set_stack_inode_uid(dst, src->st_uid);
+	btrfs_set_stack_inode_gid(dst, src->st_gid);
+	btrfs_set_stack_inode_mode(dst, src->st_mode);
+	btrfs_set_stack_inode_rdev(dst, 0);
+	btrfs_set_stack_inode_flags(dst, 0);
+	btrfs_set_stack_timespec_sec(&dst->atime, src->st_atime);
+	btrfs_set_stack_timespec_nsec(&dst->atime, 0);
+	btrfs_set_stack_timespec_sec(&dst->ctime, src->st_ctime);
+	btrfs_set_stack_timespec_nsec(&dst->ctime, 0);
+	btrfs_set_stack_timespec_sec(&dst->mtime, src->st_mtime);
+	btrfs_set_stack_timespec_nsec(&dst->mtime, 0);
+	btrfs_set_stack_timespec_sec(&dst->otime, 0);
+	btrfs_set_stack_timespec_nsec(&dst->otime, 0);
+
+	if (S_ISDIR(src->st_mode)) {
+		btrfs_set_stack_inode_size(dst, 0);
+		btrfs_set_stack_inode_nlink(dst, 1);
+	}
+	if (S_ISREG(src->st_mode)) {
+		btrfs_set_stack_inode_size(dst, (u64)src->st_size);
+		if (src->st_size <= BTRFS_MAX_INLINE_DATA_SIZE(root))
+			btrfs_set_stack_inode_nbytes(dst, src->st_size);
+		else {
+			blocks = src->st_size / sectorsize;
+			if (src->st_size % sectorsize)
+				blocks += 1;
+			blocks *= sectorsize;
+			btrfs_set_stack_inode_nbytes(dst, blocks);
+		}
+	}
+	if (S_ISLNK(src->st_mode))
+		btrfs_set_stack_inode_nbytes(dst, src->st_size + 1);
+
+	return 0;
+}
+
+static int directory_select(const struct direct *entry)
+{
+	if ((strncmp(entry->d_name, ".", entry->d_reclen) == 0) ||
+		(strncmp(entry->d_name, "..", entry->d_reclen) == 0))
+		return 0;
+	else
+		return 1;
+}
+
+static u64 calculate_dir_inode_size(char *dirname)
+{
+	int count, i;
+	struct direct **files, *cur_file;
+	u64 dir_inode_size = 0;
+
+	count = scandir(dirname, &files, directory_select, NULL);
+
+	for (i = 0; i < count; i++) {
+		cur_file = files[i];
+		dir_inode_size += strlen(cur_file->d_name);
+	}
+
+	dir_inode_size *= 2;
+	return dir_inode_size;
+}
+
+static int add_inode_items(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root,
+			   struct stat *st, char *name,
+			   u64 self_objectid, ino_t parent_inum,
+			   int dir_index_cnt, struct btrfs_inode_item *inode_ret)
+{
+	int ret;
+	struct btrfs_key inode_key;
+	struct btrfs_inode_item btrfs_inode;
+	u64 objectid;
+	u64 inode_size = 0;
+	int name_len;
+
+	name_len = strlen(name);
+	fill_inode_item(trans, root, &btrfs_inode, st);
+	objectid = self_objectid;
+
+	if (S_ISDIR(st->st_mode)) {
+		inode_size = calculate_dir_inode_size(name);
+		btrfs_set_stack_inode_size(&btrfs_inode, inode_size);
+	}
+
+	inode_key.objectid = objectid;
+	inode_key.offset = 0;
+	btrfs_set_key_type(&inode_key, BTRFS_INODE_ITEM_KEY);
+
+	ret = btrfs_insert_inode(trans, root, objectid, &btrfs_inode);
+	if (ret)
+		goto fail;
+
+	ret = btrfs_insert_inode_ref(trans, root, name, name_len,
+				     objectid, parent_inum, dir_index_cnt);
+	if (ret)
+		goto fail;
+
+	*inode_ret = btrfs_inode;
+fail:
+	return ret;
+}
+
+static int add_xattr_item(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *root, u64 objectid,
+			  const char *file_name)
+{
+	int ret;
+	int cur_name_len;
+	char xattr_list[XATTR_LIST_MAX];
+	char *cur_name;
+	char cur_value[XATTR_SIZE_MAX];
+	char delimiter = '\0';
+	char *next_location = xattr_list;
+
+	ret = llistxattr(file_name, xattr_list, XATTR_LIST_MAX);
+	if (ret < 0) {
+		fprintf(stderr, "get a list of xattr failed for %s\n",
+			file_name);
+		return ret;
+	}
+	if (ret == 0)
+		return ret;
+
+	cur_name = strtok(xattr_list, &delimiter);
+	while (cur_name != NULL) {
+		cur_name_len = strlen(cur_name);
+		next_location += cur_name_len + 1;
+
+		ret = getxattr(file_name, cur_name, cur_value, XATTR_SIZE_MAX);
+		if (ret < 0) {
+			fprintf(stderr, "get a xattr value failed for %s\n",
+				cur_name);
+		}
+
+		ret = btrfs_insert_xattr_item(trans, root, cur_name,
+					      cur_name_len, cur_value,
+					      ret, objectid);
+		if (ret) {
+			fprintf(stderr, "insert a xattr item failed for %s\n",
+				file_name);
+		}
+
+		cur_name = strtok(next_location, &delimiter);
+	}
+
+	return ret;
+}
+
+static int custom_alloc_extent(struct btrfs_root *root, u64 num_bytes,
+			       u64 hint_byte, struct btrfs_key *ins)
+{
+	u64 start;
+	u64 end;
+	u64 last = hint_byte;
+	int ret;
+	int wrapped = 0;
+	struct btrfs_block_group_cache *cache;
+
+	while (1) {
+		ret = find_first_extent_bit(&root->fs_info->free_space_cache,
+					    last, &start, &end, EXTENT_DIRTY);
+		if (ret) {
+			if (wrapped++ == 0) {
+				last = 0;
+				continue;
+			} else {
+				goto fail;
+			}
+		}
+
+		start = max(last, start);
+		last = end + 1;
+		if (last - start < num_bytes)
+			continue;
+
+		last = start + num_bytes;
+		if (test_range_bit(&root->fs_info->pinned_extents,
+				   start, last - 1, EXTENT_DIRTY, 0))
+			continue;
+
+		cache = btrfs_lookup_block_group(root->fs_info, start);
+		BUG_ON(!cache);
+		if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM ||
+		    last > cache->key.objectid + cache->key.offset) {
+			last = cache->key.objectid + cache->key.offset;
+			continue;
+		}
+
+		if (cache->flags & (BTRFS_BLOCK_GROUP_SYSTEM |
+			    BTRFS_BLOCK_GROUP_METADATA)) {
+			last = cache->key.objectid + cache->key.offset;
+			continue;
+		}
+
+		clear_extent_dirty(&root->fs_info->free_space_cache,
+				   start, start + num_bytes - 1, 0);
+
+		ins->objectid = start;
+		ins->offset = num_bytes;
+		ins->type = BTRFS_EXTENT_ITEM_KEY;
+		return 0;
+	}
+fail:
+	fprintf(stderr, "not enough free space\n");
+	return -ENOSPC;
+}
+
+static int record_file_extent(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root, u64 objectid,
+			      struct btrfs_inode_item *inode,
+			      u64 file_pos, u64 disk_bytenr,
+			      u64 num_bytes)
+{
+	int ret;
+	struct btrfs_fs_info *info = root->fs_info;
+	struct btrfs_root *extent_root = info->extent_root;
+	struct extent_buffer *leaf;
+	struct btrfs_file_extent_item *fi;
+	struct btrfs_key ins_key;
+	struct btrfs_path path;
+	struct btrfs_extent_item *ei;
+
+	btrfs_init_path(&path);
+
+	ins_key.objectid = objectid;
+	ins_key.offset = 0;
+	btrfs_set_key_type(&ins_key, BTRFS_EXTENT_DATA_KEY);
+	ret = btrfs_insert_empty_item(trans, root, &path, &ins_key,
+				      sizeof(*fi));
+	if (ret)
+		goto fail;
+	leaf = path.nodes[0];
+	fi = btrfs_item_ptr(leaf, path.slots[0],
+			    struct btrfs_file_extent_item);
+	btrfs_set_file_extent_generation(leaf, fi, trans->transid);
+	btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
+	btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
+	btrfs_set_file_extent_disk_num_bytes(leaf, fi, num_bytes);
+	btrfs_set_file_extent_offset(leaf, fi, 0);
+	btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
+	btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
+	btrfs_set_file_extent_compression(leaf, fi, 0);
+	btrfs_set_file_extent_encryption(leaf, fi, 0);
+	btrfs_set_file_extent_other_encoding(leaf, fi, 0);
+	btrfs_mark_buffer_dirty(leaf);
+
+	btrfs_release_path(root, &path);
+
+	ins_key.objectid = disk_bytenr;
+	ins_key.offset = num_bytes;
+	ins_key.type = BTRFS_EXTENT_ITEM_KEY;
+
+	ret = btrfs_insert_empty_item(trans, extent_root, &path,
+				&ins_key, sizeof(*ei));
+	if (ret == 0) {
+		leaf = path.nodes[0];
+		ei = btrfs_item_ptr(leaf, path.slots[0],
+				    struct btrfs_extent_item);
+
+		btrfs_set_extent_refs(leaf, ei, 0);
+		btrfs_set_extent_generation(leaf, ei, trans->transid);
+		btrfs_set_extent_flags(leaf, ei, BTRFS_EXTENT_FLAG_DATA);
+
+		btrfs_mark_buffer_dirty(leaf);
+		ret = btrfs_update_block_group(trans, root, disk_bytenr,
+					       num_bytes, 1, 0);
+		if (ret)
+			goto fail;
+	} else if (ret != -EEXIST) {
+		goto fail;
+	}
+
+	ret = btrfs_inc_extent_ref(trans, root, disk_bytenr, num_bytes, 0,
+				   root->root_key.objectid,
+				   objectid, 0);
+fail:
+	btrfs_release_path(root, &path);
+	return ret;
+}
+
+static int add_symbolic_link(struct btrfs_trans_handle *trans,
+			     struct btrfs_root *root,
+			     u64 objectid, const char *path_name)
+{
+	int ret;
+	u64 sectorsize = root->sectorsize;
+	char *buf = malloc(sectorsize);
+
+	ret = readlink(path_name, buf, sectorsize);
+	if (ret <= 0) {
+		fprintf(stderr, "readlink failed for %s\n", path_name);
+		goto fail;
+	}
+	if (ret > sectorsize) {
+		fprintf(stderr, "symlink too long for %s", path_name);
+		ret = -1;
+		goto fail;
+	}
+	ret = btrfs_insert_inline_extent(trans, root, objectid, 0,
+					 buf, ret + 1);
+fail:
+	free(buf);
+	return ret;
+}
+
+static int add_file_items(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *root,
+			  struct btrfs_inode_item *btrfs_inode, u64 objectid,
+			  ino_t parent_inum, struct stat *st,
+			  const char *path_name, int out_fd)
+{
+	int ret;
+	ssize_t ret_read;
+	u64 bytes_read = 0;
+	char *buffer = NULL;
+	struct btrfs_key key;
+	int blocks;
+	u32 sectorsize = root->sectorsize;
+	u64 first_block = 0;
+	u64 num_blocks = 0;
+	int fd;
+
+	fd = open(path_name, O_RDONLY);
+	if (fd == -1) {
+		fprintf(stderr, "%s open failed\n", path_name);
+		goto end;
+	}
+
+	blocks = st->st_size / sectorsize;
+	if (st->st_size % sectorsize)
+		blocks += 1;
+
+	if (st->st_size <= BTRFS_MAX_INLINE_DATA_SIZE(root)) {
+		buffer = malloc(st->st_size);
+		ret_read = pread64(fd, buffer, st->st_size, bytes_read);
+		if (ret_read == -1) {
+			fprintf(stderr, "%s read failed\n", path_name);
+			goto end;
+		}
+
+		ret = btrfs_insert_inline_extent(trans, root, objectid, 0,
+						 buffer, st->st_size);
+		goto end;
+	}
+
+	ret = custom_alloc_extent(root, blocks * sectorsize, 0, &key);
+	if (ret)
+		goto end;
+
+	first_block = key.objectid;
+	bytes_read = 0;
+	buffer = malloc(sectorsize);
+
+	do {
+		memset(buffer, 0, sectorsize);
+		ret_read = pread64(fd, buffer, sectorsize, bytes_read);
+		if (ret_read == -1) {
+			fprintf(stderr, "%s read failed\n", path_name);
+			goto end;
+		}
+
+		ret = pwrite64(out_fd, buffer, sectorsize,
+			       first_block + bytes_read);
+		if (ret != sectorsize) {
+			fprintf(stderr, "output file write failed\n");
+			goto end;
+		}
+
+		/* checksum for file data */
+		ret = btrfs_csum_file_block(trans, root->fs_info->csum_root,
+				first_block + (blocks * sectorsize),
+				first_block + bytes_read,
+				buffer, sectorsize);
+		if (ret) {
+			fprintf(stderr, "%s checksum failed\n", path_name);
+			goto end;
+		}
+
+		bytes_read += ret_read;
+		num_blocks++;
+	} while (ret_read == sectorsize);
+
+	if (num_blocks > 0) {
+		ret = record_file_extent(trans, root, objectid, btrfs_inode,
+					 first_block, first_block,
+					 blocks * sectorsize);
+		if (ret)
+			goto end;
+	}
+
+end:
+	if (buffer)
+		free(buffer);
+	close(fd);
+	return ret;
+}
+
+static char *make_path(char *dir, char *name)
+{
+	char *path;
+
+	path = malloc(strlen(dir) + strlen(name) + 2);
+	if (!path)
+		return NULL;
+	strcpy(path, dir);
+	if (dir[strlen(dir) - 1] != '/')
+		strcat(path, "/");
+	strcat(path, name);
+	return path;
+}
+
+static int traverse_directory(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root, char *dir_name,
+			      struct directory_name_entry *dir_head, int out_fd)
+{
+	int ret = 0;
+
+	struct btrfs_inode_item cur_inode;
+	struct btrfs_inode_item *inode_item;
+	int count, i, dir_index_cnt;
+	struct direct **files;
+	struct stat st;
+	struct directory_name_entry *dir_entry, *parent_dir_entry;
+	struct direct *cur_file;
+	ino_t parent_inum, cur_inum;
+	ino_t highest_inum = 0;
+	char *parent_dir_name;
+	struct btrfs_path path;
+	struct extent_buffer *leaf;
+	struct btrfs_key root_dir_key;
+	u64 root_dir_inode_size = 0;
+
+	/* Add list for source directory */
+	dir_entry = malloc(sizeof(struct directory_name_entry));
+	dir_entry->dir_name = dir_name;
+	dir_entry->path = malloc(strlen(dir_name) + 1);
+	strcpy(dir_entry->path, dir_name);
+
+	parent_inum = highest_inum + BTRFS_FIRST_FREE_OBJECTID;
+	dir_entry->inum = parent_inum;
+	list_add_tail(&dir_entry->list, &dir_head->list);
+
+	btrfs_init_path(&path);
+
+	root_dir_key.objectid = btrfs_root_dirid(&root->root_item);
+	root_dir_key.offset = 0;
+	btrfs_set_key_type(&root_dir_key, BTRFS_INODE_ITEM_KEY);
+	ret = btrfs_lookup_inode(trans, root, &path, &root_dir_key, 1);
+	if (ret) {
+		fprintf(stderr, "root dir lookup error\n");
+		goto fail;
+	}
+
+	leaf = path.nodes[0];
+	inode_item = btrfs_item_ptr(leaf, path.slots[0],
+				    struct btrfs_inode_item);
+
+	root_dir_inode_size = calculate_dir_inode_size(dir_name);
+	btrfs_set_inode_size(leaf, inode_item, root_dir_inode_size);
+	btrfs_mark_buffer_dirty(leaf);
+
+	btrfs_release_path(root, &path);
+
+	do {
+		parent_dir_entry = list_entry(dir_head->list.next,
+					      struct directory_name_entry,
+					      list);
+		list_del(&parent_dir_entry->list);
+
+		parent_inum = parent_dir_entry->inum;
+		parent_dir_name = parent_dir_entry->dir_name;
+		if (chdir(parent_dir_entry->path)) {
+			fprintf(stderr, "chdir error for %s\n",
+				parent_dir_name);
+			goto fail;
+		}
+
+		count = scandir(parent_dir_entry->path, &files,
+				directory_select, NULL);
+
+		for (i = 0; i < count; i++) {
+			cur_file = files[i];
+
+			if (lstat(cur_file->d_name, &st) == -1) {
+				fprintf(stderr, "lstat failed for file %s\n",
+					cur_file->d_name);
+				goto fail;
+			}
+
+			cur_inum = ++highest_inum + BTRFS_FIRST_FREE_OBJECTID;
+			ret = add_directory_items(trans, root,
+						  cur_inum, parent_inum,
+						  cur_file->d_name,
+						  &st, &dir_index_cnt);
+			if (ret) {
+				fprintf(stderr, "add_directory_items failed\n");
+				goto fail;
+			}
+
+			ret = add_inode_items(trans, root, &st,
+					      cur_file->d_name, cur_inum,
+					      parent_inum, dir_index_cnt,
+					      &cur_inode);
+			if (ret) {
+				fprintf(stderr, "add_inode_items failed\n");
+				goto fail;
+			}
+
+			ret = add_xattr_item(trans, root,
+					     cur_inum, cur_file->d_name);
+			if (ret) {
+				fprintf(stderr, "add_xattr_item failed\n");
+				goto fail;
+			}
+
+			if (S_ISDIR(st.st_mode)) {
+				dir_entry = malloc(sizeof(struct directory_name_entry));
+				dir_entry->dir_name = cur_file->d_name;
+				dir_entry->path = make_path(parent_dir_entry->path,
+							    cur_file->d_name);
+				dir_entry->inum = cur_inum;
+				list_add_tail(&dir_entry->list,	&dir_head->list);
+			} else if (S_ISREG(st.st_mode)) {
+				ret = add_file_items(trans, root, &cur_inode,
+						     cur_inum, parent_inum, &st,
+						     cur_file->d_name, out_fd);
+				if (ret) {
+					fprintf(stderr, "add_file_items failed\n");
+					goto fail;
+				}
+			} else if (S_ISLNK(st.st_mode)) {
+				ret = add_symbolic_link(trans, root,
+						        cur_inum, cur_file->d_name);
+				if (ret) {
+					fprintf(stderr, "add_symbolic_link failed\n");
+					goto fail;
+				}
+			}
+		}
+
+		free(parent_dir_entry->path);
+		free(parent_dir_entry);
+
+		index_cnt = 2;
+
+	} while (!list_empty(&dir_head->list));
+
+	return 0;
+fail:
+	free(parent_dir_entry->path);
+	free(parent_dir_entry);
+	return -1;
+}
+
+static int open_target(char *output_name)
+{
+	int output_fd;
+	output_fd = open(output_name, O_CREAT | O_RDWR | O_TRUNC,
+		         S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH);
+
+	return output_fd;
+}
+
+static int create_chunks(struct btrfs_trans_handle *trans,
+			 struct btrfs_root *root, u64 num_of_meta_chunks,
+			 u64 size_of_data)
+{
+	u64 chunk_start;
+	u64 chunk_size;
+	u64 meta_type = BTRFS_BLOCK_GROUP_METADATA;
+	u64 data_type = BTRFS_BLOCK_GROUP_DATA;
+	u64 minimum_data_chunk_size = 64 * 1024 * 1024;
+	u64 i;
+	int ret;
+
+	for (i = 0; i < num_of_meta_chunks; i++) {
+		ret = btrfs_alloc_chunk(trans, root->fs_info->extent_root,
+					&chunk_start, &chunk_size, meta_type);
+		BUG_ON(ret);
+		ret = btrfs_make_block_group(trans, root->fs_info->extent_root, 0,
+					     meta_type, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+					     chunk_start, chunk_size);
+		BUG_ON(ret);
+		set_extent_dirty(&root->fs_info->free_space_cache,
+				 chunk_start, chunk_start + chunk_size - 1, 0);
+	}
+
+	if (size_of_data < minimum_data_chunk_size)
+		size_of_data = minimum_data_chunk_size;
+	ret = btrfs_alloc_data_chunk(trans, root->fs_info->extent_root,
+				     &chunk_start, size_of_data, data_type);
+	BUG_ON(ret);
+	ret = btrfs_make_block_group(trans, root->fs_info->extent_root, 0,
+				     data_type, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+				     chunk_start, size_of_data);
+	BUG_ON(ret);
+	set_extent_dirty(&root->fs_info->free_space_cache,
+			 chunk_start, chunk_start + size_of_data - 1, 0);
+	return ret;
+}
+
+static int make_image(char *source_dir, struct btrfs_root *root, int out_fd)
+{
+	int ret;
+	struct btrfs_trans_handle *trans;
+
+	struct stat root_st;
+	int root_len;
+
+	struct directory_name_entry dir_head;
+
+	ret = lstat(source_dir, &root_st);
+	if (ret) {
+		fprintf(stderr, "unable to lstat the %s\n", source_dir);
+		goto fail;
+	}
+
+	root_len = strlen(source_dir);
+
+	INIT_LIST_HEAD(&dir_head.list);
+
+	trans = btrfs_start_transaction(root, 1);
+	ret = traverse_directory(trans, root, source_dir, &dir_head, out_fd);
+	if (ret) {
+		fprintf(stderr, "unable to traverse_directory\n");
+		goto fail;
+	}
+	btrfs_commit_transaction(trans, root);
+
+	printf("Making image is completed.\n");
+	return 0;
+fail:
+	fprintf(stderr, "Making image is aborted.\n");
+	return -1;
+}
+
+static u64 size_sourcedir(char *dir_name, u64 sectorsize,
+			  u64 *num_of_meta_chunks_ret, u64 *size_of_data_ret)
+{
+	u64 dir_size = 0;
+	u64 total_size = 0;
+	int ret;
+	char command[1024];
+	char path[512];
+	char *file_name = "temp_file";
+	FILE *file;
+	u64 minimum_data_size = 256 * 1024 * 1024;	/* 256MB */
+	u64 default_chunk_size = 8 * 1024 * 1024;	/* 8MB */
+	u64 allocated_meta_size = 8 * 1024 * 1024;	/* 8MB */
+	u64 allocated_total_size = 20 * 1024 * 1024;	/* 20MB */
+	u64 num_of_meta_chunks = 0;
+	u64 num_of_allocated_meta_chunks =
+			allocated_meta_size / default_chunk_size;
+
+	ret = sprintf(command, "du -B 4096 -s ");
+	if (ret < 0) {
+		fprintf(stderr, "error executing sprintf for du command\n");
+		return -1;
+	}
+	strcat(command, dir_name);
+	strcat(command, " > ");
+	strcat(command, file_name);
+	ret = system(command);
+
+	file = fopen(file_name, "r");
+	ret = fscanf(file, "%lld %s\n", &dir_size, path);
+	fclose(file);
+	remove(file_name);
+
+	dir_size *= sectorsize;
+	*size_of_data_ret = dir_size;
+
+	num_of_meta_chunks = (dir_size / 2) / default_chunk_size;
+	if (((dir_size / 2) % default_chunk_size) != 0)
+		num_of_meta_chunks++;
+	if (num_of_meta_chunks <= num_of_allocated_meta_chunks)
+		num_of_meta_chunks = 0;
+	else
+		num_of_meta_chunks -= num_of_allocated_meta_chunks;
+
+	total_size = allocated_total_size + dir_size +
+		     (num_of_meta_chunks * default_chunk_size);
+
+	*num_of_meta_chunks_ret = num_of_meta_chunks;
+
+	if (total_size < minimum_data_size)
+		total_size = minimum_data_size;
+
+	return total_size;
+}
+
+static int zero_output_file(int out_fd, u64 size, u32 sectorsize)
+{
+	int len = sectorsize;
+	int loop_num = size / sectorsize;
+	u64 location = 0;
+	char *buf = malloc(len);
+	int ret = 0, i;
+	ssize_t written;
+
+	if (!buf)
+		return -ENOMEM;
+	memset(buf, 0, len);
+	for (i = 0; i < loop_num; i++) {
+		written = pwrite64(out_fd, buf, len, location);
+		if (written != len)
+			ret = -EIO;
+		location += sectorsize;
+	}
+	free(buf);
+	return ret;
+}
+
 int main(int ac, char **av)
 {
 	char *file;
@@ -385,9 +1156,15 @@ int main(int ac, char **av)
 	int data_profile_opt = 0;
 	int metadata_profile_opt = 0;
 
+	char *source_dir = NULL;
+	int source_dir_set = 0;
+	char *output = "output.img";
+	u64 num_of_meta_chunks = 0;
+	u64 size_of_data = 0;
+
 	while(1) {
 		int c;
-		c = getopt_long(ac, av, "A:b:l:n:s:m:d:L:VM", long_options,
+		c = getopt_long(ac, av, "A:b:l:n:s:m:d:L:r:VM", long_options,
 				&option_index);
 		if (c < 0)
 			break;
@@ -430,6 +1207,10 @@ int main(int ac, char **av)
 			case 'V':
 				print_version();
 				break;
+			case 'r':
+				source_dir = optarg;
+				source_dir_set = 1;
+				break;
 			default:
 				print_usage();
 		}
@@ -443,6 +1224,8 @@ int main(int ac, char **av)
 		fprintf(stderr, "Illegal nodesize %u\n", nodesize);
 		exit(1);
 	}
+	if (source_dir_set)
+		ac++;
 	ac = ac - optind;
 	if (ac == 0)
 		print_usage();
@@ -450,28 +1233,47 @@ int main(int ac, char **av)
 	printf("\nWARNING! - %s IS EXPERIMENTAL\n", BTRFS_BUILD_VERSION);
 	printf("WARNING! - see http://btrfs.wiki.kernel.org before using\n\n");
 
-	file = av[optind++];
-	ret = check_mounted(file);
-	if (ret < 0) {
-		fprintf(stderr, "error checking %s mount status\n", file);
-		exit(1);
+	if (source_dir == 0) {
+		file = av[optind++];
+		ret = check_mounted(file);
+		if (ret < 0) {
+			fprintf(stderr, "error checking %s mount status\n", file);
+			exit(1);
+		}
+		if (ret == 1) {
+			fprintf(stderr, "%s is mounted\n", file);
+			exit(1);
+		}
+		ac--;
+		fd = open(file, O_RDWR);
+		if (fd < 0) {
+			fprintf(stderr, "unable to open %s\n", file);
+			exit(1);
+		}
+		first_fd = fd;
+		first_file = file;
+		ret = btrfs_prepare_device(fd, file, zero_end, &dev_block_count, &mixed);
+		if (block_count == 0)
+			block_count = dev_block_count;
+	} else {
+		ac = 0;
+		fd = open_target(output);
+		if (fd < 0) {
+			fprintf(stderr, "unable to open the %s\n", file);
+			exit(1);
+		}
+
+		file = output;
+		first_fd = fd;
+		first_file = file;
+		block_count = size_sourcedir(source_dir, sectorsize,
+					     &num_of_meta_chunks, &size_of_data);
+		ret = zero_output_file(fd, block_count, sectorsize);
+		if (ret) {
+			fprintf(stderr, "unable to zero the output file\n");
+			exit(1);
+		}
 	}
-	if (ret == 1) {
-		fprintf(stderr, "%s is mounted\n", file);
-		exit(1);
-	}
-	ac--;
-	fd = open(file, O_RDWR);
-	if (fd < 0) {
-		fprintf(stderr, "unable to open %s\n", file);
-		exit(1);
-	}
-	first_fd = fd;
-	first_file = file;
-	ret = btrfs_prepare_device(fd, file, zero_end, &dev_block_count,
-				   &mixed);
-	if (block_count == 0)
-		block_count = dev_block_count;
 	if (mixed) {
 		if (!metadata_profile_opt)
 			metadata_profile = 0;
@@ -558,9 +1360,11 @@ int main(int ac, char **av)
 	}
 
 raid_groups:
-	ret = create_raid_groups(trans, root, data_profile,
+	if (!source_dir_set) {
+		ret = create_raid_groups(trans, root, data_profile,
 				 metadata_profile, mixed);
-	BUG_ON(ret);
+		BUG_ON(ret);
+	}
 
 	ret = create_data_reloc_tree(trans, root);
 	BUG_ON(ret);
@@ -580,6 +1384,18 @@ raid_groups:
 
 	printf("%s\n", BTRFS_BUILD_VERSION);
 	btrfs_commit_transaction(trans, root);
+
+	if (source_dir_set) {
+		trans = btrfs_start_transaction(root, 1);
+		ret = create_chunks(trans, root,
+				    num_of_meta_chunks, size_of_data);
+		BUG_ON(ret);
+		btrfs_commit_transaction(trans, root);
+
+		ret = make_image(source_dir, root, fd);
+		BUG_ON(ret);
+	}
+
 	ret = close_ctree(root);
 	BUG_ON(ret);
 

volumes.c

@@ -857,6 +857,110 @@ again:
 	return ret;
 }
 
+int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *extent_root, u64 *start,
+			   u64 num_bytes, u64 type)
+{
+	u64 dev_offset;
+	struct btrfs_fs_info *info = extent_root->fs_info;
+	struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
+	struct btrfs_stripe *stripes;
+	struct btrfs_device *device = NULL;
+	struct btrfs_chunk *chunk;
+	struct list_head *dev_list = &extent_root->fs_info->fs_devices->devices;
+	struct list_head *cur;
+	struct map_lookup *map;
+	u64 physical;
+	u64 calc_size = 8 * 1024 * 1024;
+	int num_stripes = 1;
+	int sub_stripes = 0;
+	int ret;
+	int index;
+	int stripe_len = 64 * 1024;
+	struct btrfs_key key;
+
+	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+	key.type = BTRFS_CHUNK_ITEM_KEY;
+	ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+			      &key.offset);
+	if (ret)
+		return ret;
+
+	chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
+	if (!chunk)
+		return -ENOMEM;
+
+	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+	if (!map) {
+		kfree(chunk);
+		return -ENOMEM;
+	}
+
+	stripes = &chunk->stripe;
+	calc_size = num_bytes;
+
+	index = 0;
+	cur = dev_list->next;
+	device = list_entry(cur, struct btrfs_device, dev_list);
+
+	while (index < num_stripes) {
+		struct btrfs_stripe *stripe;
+
+		ret = btrfs_alloc_dev_extent(trans, device,
+			     info->chunk_root->root_key.objectid,
+			     BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
+			     calc_size, &dev_offset);
+		BUG_ON(ret);
+
+		device->bytes_used += calc_size;
+		ret = btrfs_update_device(trans, device);
+		BUG_ON(ret);
+
+		map->stripes[index].dev = device;
+		map->stripes[index].physical = dev_offset;
+		stripe = stripes + index;
+		btrfs_set_stack_stripe_devid(stripe, device->devid);
+		btrfs_set_stack_stripe_offset(stripe, dev_offset);
+		memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
+		physical = dev_offset;
+		index++;
+	}
+
+	/* key was set above */
+	btrfs_set_stack_chunk_length(chunk, num_bytes);
+	btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
+	btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
+	btrfs_set_stack_chunk_type(chunk, type);
+	btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
+	btrfs_set_stack_chunk_io_align(chunk, stripe_len);
+	btrfs_set_stack_chunk_io_width(chunk, stripe_len);
+	btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
+	btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
+	map->sector_size = extent_root->sectorsize;
+	map->stripe_len = stripe_len;
+	map->io_align = stripe_len;
+	map->io_width = stripe_len;
+	map->type = type;
+	map->num_stripes = num_stripes;
+	map->sub_stripes = sub_stripes;
+
+	ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
+				btrfs_chunk_item_size(num_stripes));
+	BUG_ON(ret);
+	*start = key.offset;
+
+	map->ce.start = key.offset;
+	map->ce.size = num_bytes;
+
+	ret = insert_existing_cache_extent(
+			   &extent_root->fs_info->mapping_tree.cache_tree,
+			   &map->ce);
+	BUG_ON(ret);
+
+	kfree(chunk);
+	return ret;
+}
+
 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
 {
 	cache_tree_init(&tree->cache_tree);

volumes.h

@@ -107,6 +107,9 @@ int btrfs_read_chunk_tree(struct btrfs_root *root);
 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 		      struct btrfs_root *extent_root, u64 *start,
 		      u64 *num_bytes, u64 type);
+int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *extent_root, u64 *start,
+			   u64 num_bytes, u64 type);
 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf);
 int btrfs_add_device(struct btrfs_trans_handle *trans,
 		     struct btrfs_root *root,