Write inodes to image

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 357 insertions, 0 deletions

diff --git a/mkfs/meta.c b/mkfs/meta.c
new file mode 100644
index 0000000..c48aec3
--- /dev/null
+++ b/mkfs/meta.c
@@ -0,0 +1,357 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "meta_writer.h"
+#include "mksquashfs.h"
+#include "util.h"
+
+#include <assert.h>
+#include <endian.h>
+
+static size_t hard_link_count(tree_node_t *n)
+{
+	size_t count;
+
+	if (S_ISDIR(n->mode)) {
+		count = 2;
+
+		for (n = n->data.dir->children; n != NULL; n = n->next)
+			++count;
+
+		return count;
+	}
+
+	return 1;
+}
+
+static int write_dir(meta_writer_t *dm, dir_info_t *dir)
+{
+	sqfs_dir_header_t hdr;
+	sqfs_dir_entry_t ent;
+	tree_node_t *c, *d;
+	size_t i, count;
+
+	c = dir->children;
+	dir->size = 0;
+
+	dir->start_block = dm->block_offset;
+	dir->block_offset = dm->offset;
+
+	while (c != NULL) {
+		count = 0;
+
+		for (d = c; d != NULL; d = d->next) {
+			if ((d->inode_ref >> 16) != (c->inode_ref >> 16))
+				break;
+			if ((d->inode_num - c->inode_num) > 0xFFFF)
+				break;
+			count += 1;
+		}
+
+		if (count > SQFS_MAX_DIR_ENT)
+			count = SQFS_MAX_DIR_ENT;
+
+		hdr.count = htole32(count - 1);
+		hdr.start_block = htole32(c->inode_ref >> 16);
+		hdr.inode_number = htole32(c->inode_num);
+		dir->size += sizeof(hdr);
+
+		if (meta_writer_append(dm, &hdr, sizeof(hdr)))
+			return -1;
+
+		d = c;
+
+		for (i = 0; i < count; ++i) {
+			ent.offset = htole16(c->inode_ref & 0x0000FFFF);
+			ent.inode_number = htole16(c->inode_num - d->inode_num);
+			ent.type = htole16(c->type);
+			ent.size = htole16(strlen(c->name) - 1);
+			dir->size += sizeof(ent) + strlen(c->name);
+
+			if (meta_writer_append(dm, &ent, sizeof(ent)))
+				return -1;
+			if (meta_writer_append(dm, c->name, strlen(c->name)))
+				return -1;
+
+			c = c->next;
+		}
+	}
+	return 0;
+}
+
+static int write_inode(sqfs_info_t *info, meta_writer_t *im, meta_writer_t *dm,
+		       tree_node_t *node)
+{
+	uint16_t uid_idx, gid_idx;
+	file_info_t *fi = NULL;
+	dir_info_t *di = NULL;
+	sqfs_inode_t base;
+	uint32_t bs;
+	uint64_t i;
+
+	if (id_table_id_to_index(&info->idtbl, node->uid, &uid_idx))
+		return -1;
+
+	if (id_table_id_to_index(&info->idtbl, node->gid, &gid_idx))
+		return -1;
+
+	node->inode_ref = (im->block_offset << 16) | im->offset;
+	node->inode_num = info->inode_counter++;
+
+	info->super.inode_count += 1;
+
+	switch (node->mode & S_IFMT) {
+	case S_IFSOCK: node->type = SQFS_INODE_SOCKET; break;
+	case S_IFIFO: node->type = SQFS_INODE_FIFO; break;
+	case S_IFLNK: node->type = SQFS_INODE_SLINK; break;
+	case S_IFBLK: node->type = SQFS_INODE_BDEV; break;
+	case S_IFCHR: node->type = SQFS_INODE_CDEV; break;
+	case S_IFDIR:
+		di = node->data.dir;
+		node->type = SQFS_INODE_DIR;
+
+		if (write_dir(dm, di))
+			return -1;
+
+		if ((di->start_block) > 0xFFFFFFFFUL || di->size > 0xFFFF) {
+			node->type = SQFS_INODE_EXT_DIR;
+		}
+		break;
+	case S_IFREG:
+		fi = node->data.file;
+		node->type = SQFS_INODE_FILE;
+
+		if (fi->startblock > 0xFFFFFFFFUL || fi->size > 0xFFFFFFFFUL ||
+		    hard_link_count(node) > 1) {
+			node->type = SQFS_INODE_EXT_FILE;
+		}
+		break;
+	default:
+		assert(0);
+	}
+
+	base.type = htole16(node->type);
+	base.mode = htole16(node->mode);
+	base.uid_idx = htole16(uid_idx);
+	base.gid_idx = htole16(gid_idx);
+	base.mod_time = htole32(info->opt.def_mtime);
+	base.inode_number = htole32(node->inode_num);
+
+	if (meta_writer_append(im, &base, sizeof(base)))
+		return -1;
+
+	switch (node->type) {
+	case SQFS_INODE_FIFO:
+	case SQFS_INODE_SOCKET: {
+		sqfs_inode_ipc_t ipc = {
+			.nlink = hard_link_count(node),
+		};
+
+		return meta_writer_append(im, &ipc, sizeof(ipc));
+	}
+	case SQFS_INODE_SLINK: {
+		sqfs_inode_slink_t slink = {
+			.nlink = htole32(hard_link_count(node)),
+			.target_size = htole32(strlen(node->data.slink_target)),
+		};
+
+		if (meta_writer_append(im, &slink, sizeof(slink)))
+			return -1;
+		if (meta_writer_append(im, node->data.slink_target,
+				       le32toh(slink.target_size))) {
+			return -1;
+		}
+		break;
+	}
+	case SQFS_INODE_BDEV:
+	case SQFS_INODE_CDEV: {
+		sqfs_inode_dev_t dev = {
+			.nlink = htole32(hard_link_count(node)),
+			.devno = htole32(node->data.devno),
+		};
+
+		return meta_writer_append(im, &dev, sizeof(dev));
+	}
+	case SQFS_INODE_EXT_FILE: {
+		sqfs_inode_file_ext_t ext = {
+			.blocks_start = htole64(fi->startblock),
+			.file_size = htole64(fi->size),
+			.sparse = htole64(0xFFFFFFFFFFFFFFFFUL),
+			.nlink = htole32(hard_link_count(node)),
+			.fragment_idx = htole32(fi->fragment),
+			.fragment_offset = htole32(fi->fragment_offset),
+			.xattr_idx = htole32(0xFFFFFFFF),
+		};
+
+		if (meta_writer_append(im, &ext, sizeof(ext)))
+			return -1;
+		goto out_file_blocks;
+	}
+	case SQFS_INODE_FILE: {
+		sqfs_inode_file_t reg = {
+			.blocks_start = htole32(fi->startblock),
+			.fragment_index = htole32(fi->fragment),
+			.fragment_offset = htole32(fi->fragment_offset),
+			.file_size = htole32(fi->size),
+		};
+
+		if (meta_writer_append(im, &reg, sizeof(reg)))
+			return -1;
+		goto out_file_blocks;
+	}
+	case SQFS_INODE_DIR: {
+		sqfs_inode_dir_t dir = {
+			.start_block = htole32(node->data.dir->start_block),
+			.nlink = htole32(hard_link_count(node)),
+			.size = htole16(node->data.dir->size),
+			.offset = htole16(node->data.dir->block_offset),
+			.parent_inode = node->parent ?
+				htole32(node->parent->inode_num) : htole32(1),
+		};
+
+		return meta_writer_append(im, &dir, sizeof(dir));
+	}
+	case SQFS_INODE_EXT_DIR: {
+		sqfs_inode_dir_ext_t ext = {
+			.nlink = htole32(hard_link_count(node)),
+			.size = htole32(node->data.dir->size),
+			.start_block = htole32(node->data.dir->start_block),
+			.parent_inode = node->parent ?
+				htole32(node->parent->inode_num) : htole32(1),
+			.inodex_count = htole32(0),
+			.offset = htole16(node->data.dir->block_offset),
+			.xattr_idx = htole32(0xFFFFFFFF),
+		};
+
+		return meta_writer_append(im, &ext, sizeof(ext));
+	}
+	default:
+		assert(0);
+	}
+	return 0;
+out_file_blocks:
+	for (i = 0; i < fi->size / info->super.block_size; ++i) {
+		bs = htole32(fi->blocksizes[i]);
+
+		if (meta_writer_append(im, &bs, sizeof(bs)))
+			return -1;
+	}
+	return 0;
+}
+
+static int write_child_inodes(sqfs_info_t *info, meta_writer_t *im,
+			      meta_writer_t *dm, tree_node_t *root)
+{
+	bool has_subdirs = false;
+	tree_node_t *it;
+
+	for (it = root->data.dir->children; it != NULL; it = it->next) {
+		if (S_ISDIR(it->mode)) {
+			has_subdirs = true;
+			break;
+		}
+	}
+
+	if (has_subdirs) {
+		for (it = root->data.dir->children; it != NULL; it = it->next) {
+			if (!S_ISDIR(it->mode))
+				continue;
+
+			if (write_child_inodes(info, im, dm, it))
+				return -1;
+		}
+	}
+
+	for (it = root->data.dir->children; it != NULL; it = it->next) {
+		if (write_inode(info, im, dm, it))
+			return -1;
+	}
+
+	return 0;
+}
+
+int sqfs_write_inodes(sqfs_info_t *info)
+{
+	meta_writer_t *im, *dm;
+	size_t diff;
+	ssize_t ret;
+	FILE *tmp;
+	int tmpfd;
+
+	tmp = tmpfile();
+	if (tmp == NULL) {
+		perror("tmpfile");
+		return -1;
+	}
+
+	tmpfd = fileno(tmp);
+
+	im = meta_writer_create(info->outfd, info->cmp);
+	if (im == NULL)
+		goto fail_tmp;
+
+	dm = meta_writer_create(tmpfd, info->cmp);
+	if (dm == NULL)
+		goto fail_im;
+
+	info->inode_counter = 2;
+
+	if (write_child_inodes(info, im, dm, info->fs.root))
+		goto fail;
+
+	if (write_inode(info, im, dm, info->fs.root))
+		goto fail;
+
+	if (meta_writer_flush(im))
+		goto fail;
+
+	if (meta_writer_flush(dm))
+		goto fail;
+
+	info->super.root_inode_ref = info->fs.root->inode_ref;
+
+	info->super.inode_table_start = info->super.bytes_used;
+	info->super.bytes_used += im->block_offset;
+
+	info->super.directory_table_start = info->super.bytes_used;
+	info->super.bytes_used += dm->block_offset;
+
+	if (lseek(tmpfd, 0, SEEK_SET) == (off_t)-1) {
+		perror("rewind on directory temp file");
+		goto fail;
+	}
+
+	for (;;) {
+		ret = read_retry(tmpfd, dm->data, sizeof(dm->data));
+
+		if (ret < 0) {
+			perror("read from temp file");
+			goto fail;
+		}
+		if (ret == 0)
+			break;
+
+		diff = ret;
+		ret = write_retry(info->outfd, dm->data, diff);
+
+		if (ret < 0) {
+			perror("write to image file");
+			goto fail;
+		}
+		if ((size_t)ret < diff) {
+			fputs("copying meta data to image file: "
+			      "truncated write\n", stderr);
+			goto fail;
+		}
+	}
+
+	meta_writer_destroy(dm);
+	meta_writer_destroy(im);
+	fclose(tmp);
+	return 0;
+fail:
+	meta_writer_destroy(dm);
+fail_im:
+	meta_writer_destroy(im);
+fail_tmp:
+	fclose(tmp);
+	return -1;
+}