Split fstree inode serialization, move independend part to libsquashfs.so

This commit adds a function to libsquashfs.so for writing generic inodes
to a meta writer and another function to libsqfshelper.a that turns a
tree node to an inode. That way, the tree serialization code can be
expressed in terms of those functions and a bulk of the independend code
can be moved over to libsquashfs.so

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

3 files changed, 287 insertions, 331 deletions

diff --git a/lib/sqfshelper/serialize_fstree.c b/lib/sqfshelper/serialize_fstree.c
index 53e2236..f8f3913 100644
--- a/lib/sqfshelper/serialize_fstree.c
+++ b/lib/sqfshelper/serialize_fstree.c
@@ -11,17 +11,46 @@
 #include "util.h"
 
 #include <unistd.h>
+#include <stdlib.h>
 #include <stdio.h>
 
+static int write_dir_entries(sqfs_dir_writer_t *dirw, tree_node_t *node)
+{
+	tree_node_t *it;
+	uint64_t ref;
+	int ret;
+
+	if (sqfs_dir_writer_begin(dirw))
+		return -1;
+
+	for (it = node->data.dir->children; it != NULL; it = it->next) {
+		ret = sqfs_dir_writer_add_entry(dirw, it->name, it->inode_num,
+						it->inode_ref, it->mode);
+		if (ret)
+			return -1;
+	}
+
+	if (sqfs_dir_writer_end(dirw))
+		return -1;
+
+	ref = sqfs_dir_writer_get_dir_reference(dirw);
+
+	node->data.dir->size = sqfs_dir_writer_get_size(dirw);
+	node->data.dir->start_block = ref >> 16;
+	node->data.dir->block_offset = ref & 0xFFFF;
+	return 0;
+}
+
 int sqfs_serialize_fstree(int outfd, sqfs_super_t *super, fstree_t *fs,
 			  compressor_t *cmp, id_table_t *idtbl)
 {
+	sqfs_inode_generic_t *inode;
 	sqfs_dir_writer_t *dirwr;
 	meta_writer_t *im, *dm;
+	size_t i, count;
 	uint32_t offset;
 	uint64_t block;
 	int ret = -1;
-	size_t i;
 
 	im = meta_writer_create(outfd, cmp, false);
 	if (im == NULL)
@@ -36,10 +65,37 @@ int sqfs_serialize_fstree(int outfd, sqfs_super_t *super, fstree_t *fs,
 		goto out_dm;
 
 	for (i = 2; i < fs->inode_tbl_size; ++i) {
-		if (meta_writer_write_inode(fs, idtbl, im, dirwr,
-					    fs->inode_table[i])) {
+		if (S_ISDIR(fs->inode_table[i]->mode)) {
+			if (write_dir_entries(dirwr, fs->inode_table[i]))
+				goto out;
+		}
+
+		inode = tree_node_to_inode(fs, idtbl, fs->inode_table[i],
+					   &count);
+		if (inode == NULL)
+			goto out;
+
+		if (inode->base.type == SQFS_INODE_EXT_DIR) {
+			inode->data.dir_ext.inodex_count =
+				sqfs_dir_writer_get_index_size(dirwr);
+		}
+
+		meta_writer_get_position(im, &block, &offset);
+		fs->inode_table[i]->inode_ref = (block << 16) | offset;
+
+		if (meta_writer_write_inode(im, inode, count)) {
+			free(inode);
 			goto out;
 		}
+
+		if (inode->base.type == SQFS_INODE_EXT_DIR) {
+			if (sqfs_dir_writer_write_index(dirwr, im)) {
+				free(inode);
+				goto out;
+			}
+		}
+
+		free(inode);
 	}
 
 	if (meta_writer_flush(im))
diff --git a/lib/sqfshelper/tree_node_to_inode.c b/lib/sqfshelper/tree_node_to_inode.c
new file mode 100644
index 0000000..21e30dd
--- /dev/null
+++ b/lib/sqfshelper/tree_node_to_inode.c
@@ -0,0 +1,228 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * write_inode.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "highlevel.h"
+#include "sqfs/inode.h"
+#include "sqfs/dir.h"
+#include "util.h"
+
+#include <assert.h>
+#include <endian.h>
+#include <stdlib.h>
+#include <string.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 get_type(tree_node_t *node)
+{
+	switch (node->mode & S_IFMT) {
+	case S_IFSOCK:
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_SOCKET;
+		return SQFS_INODE_SOCKET;
+	case S_IFIFO:
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_FIFO;
+		return SQFS_INODE_FIFO;
+	case S_IFLNK:
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_SLINK;
+		return SQFS_INODE_SLINK;
+	case S_IFBLK:
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_BDEV;
+		return SQFS_INODE_BDEV;
+	case S_IFCHR:
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_CDEV;
+		return SQFS_INODE_CDEV;
+	case S_IFREG: {
+		file_info_t *fi = node->data.file;
+
+		if (node->xattr != NULL || fi->sparse > 0)
+			return SQFS_INODE_EXT_FILE;
+
+		if (fi->startblock > 0xFFFFFFFFUL || fi->size > 0xFFFFFFFFUL)
+			return SQFS_INODE_EXT_FILE;
+
+		return SQFS_INODE_FILE;
+	}
+	case S_IFDIR: {
+		dir_info_t *di = node->data.dir;
+
+		if (node->xattr != NULL)
+			return SQFS_INODE_EXT_DIR;
+
+		if (di->start_block > 0xFFFFFFFFUL || di->size > 0xFFFF)
+			return SQFS_INODE_EXT_DIR;
+
+		return SQFS_INODE_DIR;
+	}
+	}
+	assert(0);
+}
+
+sqfs_inode_generic_t *tree_node_to_inode(fstree_t *fs, id_table_t *idtbl,
+					 tree_node_t *node,
+					 size_t *file_num_blocks)
+{
+	size_t i, extra = 0, block_count = 0;
+	sqfs_inode_generic_t *inode;
+	uint16_t uid_idx, gid_idx;
+	uint32_t xattr = 0xFFFFFFFF;
+	file_info_t *fi = NULL;
+
+	if (S_ISLNK(node->mode)) {
+		extra = strlen(node->data.slink_target);
+	} else if (S_ISREG(node->mode)) {
+		fi = node->data.file;
+
+		block_count = fi->size / fs->block_size;
+
+		if ((fi->size % fs->block_size) != 0 &&
+		    !(fi->flags & FILE_FLAG_HAS_FRAGMENT)) {
+			++block_count;
+		}
+
+		extra = block_count * sizeof(uint32_t);
+	}
+
+	inode = alloc_flex(sizeof(*inode), 1, extra);
+	if (inode == NULL) {
+		perror("creating inode from file system tree node");
+		return NULL;
+	}
+
+	if (S_ISLNK(node->mode)) {
+		inode->slink_target = (char *)inode->extra;
+
+		memcpy(inode->extra, node->data.slink_target, extra);
+	} else if (S_ISREG(node->mode)) {
+		inode->block_sizes = (uint32_t *)inode->extra;
+
+		for (i = 0; i < block_count; ++i) {
+			inode->block_sizes[i] =
+				node->data.file->blocks[i].size;
+		}
+	}
+
+	if (id_table_id_to_index(idtbl, node->uid, &uid_idx))
+		goto fail;
+
+	if (id_table_id_to_index(idtbl, node->gid, &gid_idx))
+		goto fail;
+
+	if (node->xattr != NULL)
+		xattr = node->xattr->index;
+
+	inode->base.type = get_type(node);
+	inode->base.mode = node->mode;
+	inode->base.uid_idx = uid_idx;
+	inode->base.gid_idx = gid_idx;
+	inode->base.mod_time = node->mod_time;
+	inode->base.inode_number = node->inode_num;
+
+	switch (inode->base.type) {
+	case SQFS_INODE_FIFO:
+	case SQFS_INODE_SOCKET:
+		inode->data.ipc.nlink = hard_link_count(node);
+		break;
+	case SQFS_INODE_EXT_FIFO:
+	case SQFS_INODE_EXT_SOCKET:
+		inode->data.ipc_ext.nlink = hard_link_count(node);
+		inode->data.ipc_ext.xattr_idx = xattr;
+		break;
+	case SQFS_INODE_SLINK:
+		inode->data.slink.nlink = hard_link_count(node);
+		inode->data.slink.target_size = extra;
+		break;
+	case SQFS_INODE_EXT_SLINK:
+		inode->data.slink_ext.nlink = hard_link_count(node);
+		inode->data.slink_ext.target_size = extra;
+		inode->data.slink_ext.xattr_idx = xattr;
+		break;
+	case SQFS_INODE_BDEV:
+	case SQFS_INODE_CDEV:
+		inode->data.dev.nlink = hard_link_count(node);
+		inode->data.dev.devno = node->data.devno;
+		break;
+	case SQFS_INODE_EXT_BDEV:
+	case SQFS_INODE_EXT_CDEV:
+		inode->data.dev_ext.nlink = hard_link_count(node);
+		inode->data.dev_ext.devno = node->data.devno;
+		inode->data.dev_ext.xattr_idx = xattr;
+		break;
+	case SQFS_INODE_FILE:
+		inode->data.file.blocks_start = fi->startblock;
+		inode->data.file.fragment_index = 0xFFFFFFFF;
+		inode->data.file.fragment_offset = 0xFFFFFFFF;
+		inode->data.file.file_size = fi->size;
+
+		if ((fi->size % fs->block_size) != 0 &&
+		    (fi->flags & FILE_FLAG_HAS_FRAGMENT)) {
+			inode->data.file.fragment_index = fi->fragment;
+			inode->data.file.fragment_offset = fi->fragment_offset;
+		}
+		break;
+	case SQFS_INODE_EXT_FILE:
+		inode->data.file_ext.blocks_start = fi->startblock;
+		inode->data.file_ext.file_size = fi->size;
+		inode->data.file_ext.sparse = fi->sparse;
+		inode->data.file_ext.nlink = hard_link_count(node);
+		inode->data.file_ext.fragment_idx = 0xFFFFFFFF;
+		inode->data.file_ext.fragment_offset = 0xFFFFFFFF;
+		inode->data.file_ext.xattr_idx = xattr;
+
+		if ((fi->size % fs->block_size) != 0 &&
+		    (fi->flags & FILE_FLAG_HAS_FRAGMENT)) {
+			inode->data.file_ext.fragment_idx = fi->fragment;
+			inode->data.file_ext.fragment_offset =
+				fi->fragment_offset;
+		}
+		break;
+	case SQFS_INODE_DIR:
+		inode->data.dir.start_block = node->data.dir->start_block;
+		inode->data.dir.nlink = hard_link_count(node);
+		inode->data.dir.size = node->data.dir->size;
+		inode->data.dir.offset = node->data.dir->block_offset;
+		inode->data.dir.parent_inode = node->parent ?
+			node->parent->inode_num : 1;
+		break;
+	case SQFS_INODE_EXT_DIR:
+		inode->data.dir_ext.nlink = hard_link_count(node);
+		inode->data.dir_ext.size = node->data.dir->size;
+		inode->data.dir_ext.start_block = node->data.dir->start_block;
+		inode->data.dir_ext.parent_inode = node->parent ?
+			node->parent->inode_num : 1;
+		inode->data.dir_ext.offset = node->data.dir->block_offset;
+		inode->data.dir_ext.xattr_idx = xattr;
+		break;
+	default:
+		goto fail;
+	}
+
+	*file_num_blocks = block_count;
+	return inode;
+fail:
+	free(inode);
+	return NULL;
+}
diff --git a/lib/sqfshelper/write_inode.c b/lib/sqfshelper/write_inode.c
deleted file mode 100644
index d9dfe53..0000000
--- a/lib/sqfshelper/write_inode.c
+++ /dev/null
@@ -1,328 +0,0 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
-/*
- * write_inode.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#include "config.h"
-
-#include "highlevel.h"
-#include "sqfs/inode.h"
-#include "sqfs/dir.h"
-#include "util.h"
-
-#include <assert.h>
-#include <endian.h>
-#include <stdlib.h>
-#include <string.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 get_type(tree_node_t *node)
-{
-	switch (node->mode & S_IFMT) {
-	case S_IFSOCK:
-		if (node->xattr != NULL)
-			return SQFS_INODE_EXT_SOCKET;
-		return SQFS_INODE_SOCKET;
-	case S_IFIFO:
-		if (node->xattr != NULL)
-			return SQFS_INODE_EXT_FIFO;
-		return SQFS_INODE_FIFO;
-	case S_IFLNK:
-		if (node->xattr != NULL)
-			return SQFS_INODE_EXT_SLINK;
-		return SQFS_INODE_SLINK;
-	case S_IFBLK:
-		if (node->xattr != NULL)
-			return SQFS_INODE_EXT_BDEV;
-		return SQFS_INODE_BDEV;
-	case S_IFCHR:
-		if (node->xattr != NULL)
-			return SQFS_INODE_EXT_CDEV;
-		return SQFS_INODE_CDEV;
-	case S_IFREG: {
-		file_info_t *fi = node->data.file;
-
-		if (node->xattr != NULL || fi->sparse > 0)
-			return SQFS_INODE_EXT_FILE;
-
-		if (fi->startblock > 0xFFFFFFFFUL || fi->size > 0xFFFFFFFFUL)
-			return SQFS_INODE_EXT_FILE;
-
-		if (hard_link_count(node) > 1)
-			return SQFS_INODE_EXT_FILE;
-
-		return SQFS_INODE_FILE;
-	}
-	case S_IFDIR: {
-		dir_info_t *di = node->data.dir;
-
-		if (node->xattr != NULL)
-			return SQFS_INODE_EXT_DIR;
-
-		if (di->start_block > 0xFFFFFFFFUL || di->size > 0xFFFF)
-			return SQFS_INODE_EXT_DIR;
-
-		return SQFS_INODE_DIR;
-	}
-	}
-	assert(0);
-}
-
-static int write_file_blocks(fstree_t *fs, file_info_t *fi, meta_writer_t *im)
-{
-	uint64_t i, count = fi->size / fs->block_size;
-	uint32_t bs;
-
-	if ((fi->size % fs->block_size) != 0 &&
-	    !(fi->flags & FILE_FLAG_HAS_FRAGMENT)) {
-		++count;
-	}
-
-	for (i = 0; i < count; ++i) {
-		bs = htole32(fi->blocks[i].size);
-
-		if (meta_writer_append(im, &bs, sizeof(bs)))
-			return -1;
-	}
-	return 0;
-}
-
-static int write_dir_entries(sqfs_dir_writer_t *dirw, tree_node_t *node)
-{
-	tree_node_t *it;
-	uint64_t ref;
-	int ret;
-
-	if (sqfs_dir_writer_begin(dirw))
-		return -1;
-
-	for (it = node->data.dir->children; it != NULL; it = it->next) {
-		ret = sqfs_dir_writer_add_entry(dirw, it->name, it->inode_num,
-						it->inode_ref, it->mode);
-		if (ret)
-			return -1;
-	}
-
-	if (sqfs_dir_writer_end(dirw))
-		return -1;
-
-	ref = sqfs_dir_writer_get_dir_reference(dirw);
-
-	node->data.dir->size = sqfs_dir_writer_get_size(dirw);
-	node->data.dir->start_block = ref >> 16;
-	node->data.dir->block_offset = ref & 0xFFFF;
-	return 0;
-}
-
-int meta_writer_write_inode(fstree_t *fs, id_table_t *idtbl, meta_writer_t *im,
-			    sqfs_dir_writer_t *dirw, tree_node_t *node)
-{
-	uint16_t uid_idx, gid_idx;
-	sqfs_inode_t base;
-	uint32_t offset;
-	uint64_t block;
-
-	if (id_table_id_to_index(idtbl, node->uid, &uid_idx))
-		return -1;
-
-	if (id_table_id_to_index(idtbl, node->gid, &gid_idx))
-		return -1;
-
-	meta_writer_get_position(im, &block, &offset);
-	node->inode_ref = (block << 16) | offset;
-
-	if (S_ISDIR(node->mode)) {
-		if (write_dir_entries(dirw, node))
-			return -1;
-	}
-
-	base.type = htole16(get_type(node));
-	base.mode = htole16(node->mode);
-	base.uid_idx = htole16(uid_idx);
-	base.gid_idx = htole16(gid_idx);
-	base.mod_time = htole32(node->mod_time);
-	base.inode_number = htole32(node->inode_num);
-
-	if (meta_writer_append(im, &base, sizeof(base)))
-		return -1;
-
-	switch (le16toh(base.type)) {
-	case SQFS_INODE_FIFO:
-	case SQFS_INODE_SOCKET: {
-		sqfs_inode_ipc_t ipc = {
-			.nlink = htole32(hard_link_count(node)),
-		};
-
-		return meta_writer_append(im, &ipc, sizeof(ipc));
-	}
-	case SQFS_INODE_EXT_FIFO:
-	case SQFS_INODE_EXT_SOCKET: {
-		sqfs_inode_ipc_ext_t ipc = {
-			.nlink = htole32(hard_link_count(node)),
-			.xattr_idx = htole32(0xFFFFFFFF),
-		};
-
-		if (node->xattr != NULL)
-			ipc.xattr_idx = htole32(node->xattr->index);
-
-		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_EXT_SLINK: {
-		sqfs_inode_slink_t slink = {
-			.nlink = htole32(hard_link_count(node)),
-			.target_size = htole32(strlen(node->data.slink_target)),
-		};
-		uint32_t xattr = htole32(0xFFFFFFFF);
-
-		if (node->xattr != NULL)
-			xattr = htole32(node->xattr->index);
-
-		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;
-		}
-		if (meta_writer_append(im, &xattr, sizeof(xattr)))
-			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_BDEV:
-	case SQFS_INODE_EXT_CDEV: {
-		sqfs_inode_dev_ext_t dev = {
-			.nlink = htole32(hard_link_count(node)),
-			.devno = htole32(node->data.devno),
-			.xattr_idx = htole32(0xFFFFFFFF),
-		};
-
-		if (node->xattr != NULL)
-			dev.xattr_idx = htole32(node->xattr->index);
-
-		return meta_writer_append(im, &dev, sizeof(dev));
-	}
-	case SQFS_INODE_EXT_FILE: {
-		file_info_t *fi = node->data.file;
-		sqfs_inode_file_ext_t ext = {
-			.blocks_start = htole64(fi->startblock),
-			.file_size = htole64(fi->size),
-			.sparse = htole64(fi->sparse),
-			.nlink = htole32(hard_link_count(node)),
-			.fragment_idx = htole32(0xFFFFFFFF),
-			.fragment_offset = htole32(0xFFFFFFFF),
-			.xattr_idx = htole32(0xFFFFFFFF),
-		};
-
-		if ((fi->size % fs->block_size) != 0) {
-			ext.fragment_idx = htole32(fi->fragment);
-			ext.fragment_offset = htole32(fi->fragment_offset);
-		}
-
-		if (node->xattr != NULL)
-			ext.xattr_idx = htole32(node->xattr->index);
-
-		if (meta_writer_append(im, &ext, sizeof(ext)))
-			return -1;
-		return write_file_blocks(fs, fi, im);
-	}
-	case SQFS_INODE_FILE: {
-		file_info_t *fi = node->data.file;
-		sqfs_inode_file_t reg = {
-			.blocks_start = htole32(fi->startblock),
-			.fragment_index = htole32(0xFFFFFFFF),
-			.fragment_offset = htole32(0xFFFFFFFF),
-			.file_size = htole32(fi->size),
-		};
-
-		if ((fi->size % fs->block_size) != 0) {
-			reg.fragment_index = htole32(fi->fragment);
-			reg.fragment_offset = htole32(fi->fragment_offset);
-		}
-
-		if (meta_writer_append(im, &reg, sizeof(reg)))
-			return -1;
-		return write_file_blocks(fs, fi, im);
-	}
-	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: {
-		size_t idx_size;
-		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),
-		};
-
-		if (node->xattr != NULL)
-			ext.xattr_idx = htole32(node->xattr->index);
-
-		idx_size = sqfs_dir_writer_get_index_size(dirw);
-
-		if (idx_size > 0)
-			ext.inodex_count = htole32(idx_size - 1);
-
-		if (meta_writer_append(im, &ext, sizeof(ext)))
-			return -1;
-
-		if (sqfs_dir_writer_write_index(dirw, im))
-			return -1;
-		break;
-	}
-	default:
-		assert(0);
-	}
-	return 0;
-}