Add helper functions for working with inodes

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

11 files changed, 465 insertions, 167 deletions

diff --git a/difftool/compare_files.c b/difftool/compare_files.c
index a977d95..aa11f43 100644
--- a/difftool/compare_files.c
+++ b/difftool/compare_files.c
@@ -33,17 +33,8 @@ int compare_files(sqfsdiff_t *sd, const sqfs_inode_generic_t *old,
 	uint64_t offset, diff, oldsz, newsz;
 	int status = 0, ret;
 
-	if (old->base.type == SQFS_INODE_EXT_FILE) {
-		oldsz = old->data.file_ext.file_size;
-	} else {
-		oldsz = old->data.file.file_size;
-	}
-
-	if (new->base.type == SQFS_INODE_EXT_FILE) {
-		newsz = new->data.file_ext.file_size;
-	} else {
-		newsz = new->data.file.file_size;
-	}
+	sqfs_inode_get_file_size(old, &oldsz);
+	sqfs_inode_get_file_size(new, &newsz);
 
 	if (oldsz != newsz)
 		goto out_different;
diff --git a/include/sqfs/inode.h b/include/sqfs/inode.h
index 0019360..a65215b 100644
--- a/include/sqfs/inode.h
+++ b/include/sqfs/inode.h
@@ -452,4 +452,138 @@ struct sqfs_inode_generic_t {
 	uint8_t extra[];
 };
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Get the extended attribute index of an inode
+ *
+ * For basic inodes, this returns the inode index 0xFFFFFFFF, i.e. the
+ * sentinel value indicating that there are no xattrs.
+ *
+ * @param inode A pointer to an inode.
+ * @param out Returns the extended attribute index on success.
+ *
+ * @return Zero on success, an @ref SQFS_ERROR_CORRUPTED if the node has
+ *         an unknown type set.
+ */
+SQFS_API int sqfs_inode_get_xattr_index(const sqfs_inode_generic_t *inode,
+					uint32_t *out);
+
+/**
+ * @brief Convert a basic inode to an extended inode.
+ *
+ * For inodes that already have an extended type, this is a no-op.
+ *
+ * @param inode A pointer to an inode.
+ *
+ * @return Zero on success, an @ref SQFS_ERROR_CORRUPTED if the node has
+ *         an unknown type set.
+ */
+SQFS_API int sqfs_inode_make_extended(sqfs_inode_generic_t *inode);
+
+/**
+ * @brief Convert an extended inode to a basic inode if possible.
+ *
+ * For inodes that already have a basic type, this is a no-op. If the inode
+ * has values set that the coresponding basic type doesn't support (e.g. it
+ * has an xattr index set or a regular file which requires 64 bit size
+ * counter), it is left as an extended type and success state is returned.
+ *
+ * @param inode A pointer to an inode.
+ *
+ * @return Zero on success, an @ref SQFS_ERROR_CORRUPTED if the node has
+ *         an unknown type set.
+ */
+SQFS_API int sqfs_inode_make_basic(sqfs_inode_generic_t *inode);
+
+/**
+ * @brief Update the file size of a regular file inode.
+ *
+ * If the new size is wider than 32 bit, a basic file inode is transparently
+ * promoted to an extended file inode. For extended inodes, if the new size
+ * is small enough and was the only requirement for the extended type, the
+ * node is transparently demoted to a basic file inode.
+ *
+ * @param inode A pointer to an inode.
+ * @param size The new size to set.
+ *
+ * @return Zero on success, @ref SQFS_ERROR_NOT_FILE if the node is
+ *         not a regular file.
+ */
+SQFS_API int sqfs_inode_set_file_size(sqfs_inode_generic_t *inode,
+				      uint64_t size);
+
+/**
+ * @brief Update the location of the first data block of a regular file inode.
+ *
+ * If the new location is wider than 32 bit, a basic file inode is
+ * transparently promoted to an extended file inode. For extended inodes,
+ * if the new size is small enough and was the only requirement for the
+ * extended type, the node is transparently demoted to a basic file inode.
+ *
+ * @param inode A pointer to an inode.
+ * @param location The new location to set.
+ *
+ * @return Zero on success, @ref SQFS_ERROR_NOT_FILE if the node is
+ *         not a regular file.
+ */
+SQFS_API int sqfs_inode_set_file_block_start(sqfs_inode_generic_t *inode,
+					     uint64_t location);
+
+/**
+ * @brief Update the file fragment location of a regular file inode.
+ *
+ * @param inode A pointer to an inode.
+ * @param index The new fragment index to set.
+ * @param offset The new fragment offset to set.
+ *
+ * @return Zero on success, @ref SQFS_ERROR_NOT_FILE if the node is
+ *         not a regular file.
+ */
+SQFS_API int sqfs_inode_set_frag_location(sqfs_inode_generic_t *inode,
+					  uint32_t index, uint32_t offset);
+
+/**
+ * @brief Get the file size of a regular file inode.
+ *
+ * @param inode A pointer to an inode.
+ * @param size Returns the file size.
+ *
+ * @return Zero on success, @ref SQFS_ERROR_NOT_FILE if the node is
+ *         not a regular file.
+ */
+SQFS_API int sqfs_inode_get_file_size(const sqfs_inode_generic_t *inode,
+				      uint64_t *size);
+
+/**
+ * @brief Get the file fragment location of a regular file inode.
+ *
+ * @param inode A pointer to an inode.
+ * @param index Returns the fragment index.
+ * @param offset Returns the fragment offset.
+ *
+ * @return Zero on success, @ref SQFS_ERROR_NOT_FILE if the node is
+ *         not a regular file.
+ */
+SQFS_API int sqfs_inode_get_frag_location(const sqfs_inode_generic_t *inode,
+					  uint32_t *index, uint32_t *offset);
+
+/**
+ * @brief Get the location of the first data block of a regular file inode.
+ *
+ * @param inode A pointer to an inode.
+ * @param location Returns the location.
+ *
+ * @return Zero on success, @ref SQFS_ERROR_NOT_FILE if the node is
+ *         not a regular file.
+ */
+SQFS_API int sqfs_inode_get_file_block_start(const sqfs_inode_generic_t *inode,
+					     uint64_t *location);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* SQFS_INODE_H */
diff --git a/lib/sqfs/Makemodule.am b/lib/sqfs/Makemodule.am
index 16a07e9..44b5531 100644
--- a/lib/sqfs/Makemodule.am
+++ b/lib/sqfs/Makemodule.am
@@ -17,6 +17,7 @@ libsquashfs_la_SOURCES += lib/sqfs/dir_writer.c lib/sqfs/xattr_reader.c
 libsquashfs_la_SOURCES += lib/sqfs/read_table.c lib/sqfs/comp/compressor.c
 libsquashfs_la_SOURCES += lib/sqfs/io_stdin.c lib/sqfs/comp/internal.h
 libsquashfs_la_SOURCES += lib/sqfs/dir_reader.c lib/sqfs/read_tree.c
+libsquashfs_la_SOURCES += lib/sqfs/inode.c
 libsquashfs_la_SOURCES += lib/sqfs/blk_proc/process_block.c lib/sqfs/io.c
 libsquashfs_la_SOURCES += lib/sqfs/blk_proc/internal.h lib/sqfs/data_reader.c
 libsquashfs_la_CPPFLAGS = $(AM_CPPFLAGS)
diff --git a/lib/sqfs/data_reader.c b/lib/sqfs/data_reader.c
index 3de59ff..2603cfe 100644
--- a/lib/sqfs/data_reader.c
+++ b/lib/sqfs/data_reader.c
@@ -209,15 +209,8 @@ int sqfs_data_reader_get_block(sqfs_data_reader_t *data,
 	size_t i, unpacked_size;
 	uint64_t off, filesz;
 
-	if (inode->base.type == SQFS_INODE_FILE) {
-		off = inode->data.file.blocks_start;
-		filesz = inode->data.file.file_size;
-	} else if (inode->base.type == SQFS_INODE_EXT_FILE) {
-		off = inode->data.file_ext.blocks_start;
-		filesz = inode->data.file_ext.file_size;
-	} else {
-		return SQFS_ERROR_NOT_FILE;
-	}
+	sqfs_inode_get_file_block_start(inode, &off);
+	sqfs_inode_get_file_size(inode, &filesz);
 
 	if (index >= inode->num_file_blocks)
 		return SQFS_ERROR_OUT_OF_BOUNDS;
@@ -241,17 +234,8 @@ int sqfs_data_reader_get_fragment(sqfs_data_reader_t *data,
 	sqfs_block_t *blk;
 	uint64_t filesz;
 
-	if (inode->base.type == SQFS_INODE_EXT_FILE) {
-		filesz = inode->data.file_ext.file_size;
-		frag_idx = inode->data.file_ext.fragment_idx;
-		frag_off = inode->data.file_ext.fragment_offset;
-	} else if (inode->base.type == SQFS_INODE_FILE) {
-		filesz = inode->data.file.file_size;
-		frag_idx = inode->data.file.fragment_index;
-		frag_off = inode->data.file.fragment_offset;
-	} else {
-		return -1;
-	}
+	sqfs_inode_get_file_size(inode, &filesz);
+	sqfs_inode_get_frag_location(inode, &frag_idx, &frag_off);
 
 	if (inode->num_file_blocks * data->block_size >= filesz) {
 		*out = NULL;
@@ -287,17 +271,9 @@ ssize_t sqfs_data_reader_read(sqfs_data_reader_t *data,
 	char *ptr;
 
 	/* work out file location and size */
-	if (inode->base.type == SQFS_INODE_EXT_FILE) {
-		off = inode->data.file_ext.blocks_start;
-		filesz = inode->data.file_ext.file_size;
-		frag_idx = inode->data.file_ext.fragment_idx;
-		frag_off = inode->data.file_ext.fragment_offset;
-	} else {
-		off = inode->data.file.blocks_start;
-		filesz = inode->data.file.file_size;
-		frag_idx = inode->data.file.fragment_index;
-		frag_off = inode->data.file.fragment_offset;
-	}
+	sqfs_inode_get_file_size(inode, &filesz);
+	sqfs_inode_get_frag_location(inode, &frag_idx, &frag_off);
+	sqfs_inode_get_file_block_start(inode, &off);
 
 	/* find location of the first block */
 	i = 0;
diff --git a/lib/sqfs/inode.c b/lib/sqfs/inode.c
new file mode 100644
index 0000000..d6c013c
--- /dev/null
+++ b/lib/sqfs/inode.c
@@ -0,0 +1,290 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * inode.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "config.h"
+
+#include "sqfs/inode.h"
+#include "sqfs/error.h"
+
+static int inverse_type[] = {
+	[SQFS_INODE_DIR] = SQFS_INODE_EXT_DIR,
+	[SQFS_INODE_FILE] = SQFS_INODE_EXT_FILE,
+	[SQFS_INODE_SLINK] = SQFS_INODE_EXT_SLINK,
+	[SQFS_INODE_BDEV] = SQFS_INODE_EXT_BDEV,
+	[SQFS_INODE_CDEV] = SQFS_INODE_EXT_CDEV,
+	[SQFS_INODE_FIFO] = SQFS_INODE_EXT_FIFO,
+	[SQFS_INODE_SOCKET] = SQFS_INODE_EXT_SOCKET,
+	[SQFS_INODE_EXT_DIR] = SQFS_INODE_DIR,
+	[SQFS_INODE_EXT_FILE] = SQFS_INODE_FILE,
+	[SQFS_INODE_EXT_SLINK] = SQFS_INODE_SLINK,
+	[SQFS_INODE_EXT_BDEV] = SQFS_INODE_BDEV,
+	[SQFS_INODE_EXT_CDEV] = SQFS_INODE_CDEV,
+	[SQFS_INODE_EXT_FIFO] = SQFS_INODE_FIFO,
+	[SQFS_INODE_EXT_SOCKET] = SQFS_INODE_SOCKET,
+};
+
+int sqfs_inode_get_xattr_index(const sqfs_inode_generic_t *inode,
+			       uint32_t *out)
+{
+	switch (inode->base.type) {
+	case SQFS_INODE_DIR:
+	case SQFS_INODE_FILE:
+	case SQFS_INODE_SLINK:
+	case SQFS_INODE_BDEV:
+	case SQFS_INODE_CDEV:
+	case SQFS_INODE_FIFO:
+	case SQFS_INODE_SOCKET:
+		*out = 0xFFFFFFFF;
+		break;
+	case SQFS_INODE_EXT_DIR:
+		*out = inode->data.dir_ext.xattr_idx;
+		break;
+	case SQFS_INODE_EXT_FILE:
+		*out = inode->data.file_ext.xattr_idx;
+		break;
+	case SQFS_INODE_EXT_SLINK:
+		*out = inode->data.slink_ext.xattr_idx;
+		break;
+	case SQFS_INODE_EXT_BDEV:
+	case SQFS_INODE_EXT_CDEV:
+		*out = inode->data.dev_ext.xattr_idx;
+		break;
+	case SQFS_INODE_EXT_FIFO:
+	case SQFS_INODE_EXT_SOCKET:
+		*out = inode->data.ipc_ext.xattr_idx;
+		break;
+	default:
+		return SQFS_ERROR_CORRUPTED;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_make_extended(sqfs_inode_generic_t *inode)
+{
+	switch (inode->base.type) {
+	case SQFS_INODE_DIR: {
+		sqfs_inode_dir_ext_t temp = {
+			.nlink = inode->data.dir.nlink,
+			.size = inode->data.dir.size,
+			.start_block = inode->data.dir.start_block,
+			.parent_inode = inode->data.dir.parent_inode,
+			.inodex_count = 0,
+			.offset = inode->data.dir.offset,
+			.xattr_idx = 0xFFFFFFFF,
+		};
+		inode->data.dir_ext = temp;
+		break;
+	}
+	case SQFS_INODE_FILE: {
+		sqfs_inode_file_ext_t temp = {
+			.blocks_start = inode->data.file.blocks_start,
+			.file_size = inode->data.file.file_size,
+			.sparse = 0,
+			.nlink = 1,
+			.fragment_idx = inode->data.file.fragment_index,
+			.fragment_offset = inode->data.file.fragment_offset,
+			.xattr_idx = 0xFFFFFFFF,
+		};
+		inode->data.file_ext = temp;
+		break;
+	}
+	case SQFS_INODE_SLINK:
+		inode->data.slink_ext.xattr_idx = 0xFFFFFFFF;
+		break;
+	case SQFS_INODE_BDEV:
+	case SQFS_INODE_CDEV:
+		inode->data.dev_ext.xattr_idx = 0xFFFFFFFF;
+		break;
+	case SQFS_INODE_FIFO:
+	case SQFS_INODE_SOCKET:
+		inode->data.dev_ext.xattr_idx = 0xFFFFFFFF;
+		break;
+	case SQFS_INODE_EXT_DIR:
+	case SQFS_INODE_EXT_FILE:
+	case SQFS_INODE_EXT_SLINK:
+	case SQFS_INODE_EXT_BDEV:
+	case SQFS_INODE_EXT_CDEV:
+	case SQFS_INODE_EXT_FIFO:
+	case SQFS_INODE_EXT_SOCKET:
+		return 0;
+	default:
+		return SQFS_ERROR_CORRUPTED;
+	}
+
+	inode->base.type = inverse_type[inode->base.type];
+	return 0;
+}
+
+int sqfs_inode_make_basic(sqfs_inode_generic_t *inode)
+{
+	uint32_t xattr;
+	int err;
+
+	err = sqfs_inode_get_xattr_index(inode, &xattr);
+	if (err != 0 || xattr != 0xFFFFFFFF)
+		return err;
+
+	switch (inode->base.type) {
+	case SQFS_INODE_DIR:
+	case SQFS_INODE_FILE:
+	case SQFS_INODE_SLINK:
+	case SQFS_INODE_BDEV:
+	case SQFS_INODE_CDEV:
+	case SQFS_INODE_FIFO:
+	case SQFS_INODE_SOCKET:
+		return 0;
+	case SQFS_INODE_EXT_DIR: {
+		sqfs_inode_dir_t temp = {
+			.start_block = inode->data.dir_ext.start_block,
+			.nlink = inode->data.dir_ext.nlink,
+			.size = inode->data.dir_ext.size,
+			.offset = inode->data.dir_ext.offset,
+			.parent_inode = inode->data.dir_ext.parent_inode,
+		};
+
+		if (inode->data.dir_ext.size > 0x0FFFF)
+			return 0;
+
+		inode->data.dir = temp;
+		break;
+	}
+	case SQFS_INODE_EXT_FILE: {
+		sqfs_inode_file_t temp = {
+			.blocks_start = inode->data.file_ext.blocks_start,
+			.fragment_index = inode->data.file_ext.fragment_idx,
+			.fragment_offset = inode->data.file_ext.fragment_offset,
+			.file_size = inode->data.file_ext.file_size,
+		};
+
+		if (inode->data.file_ext.blocks_start > 0x0FFFFFFFFUL)
+			return 0;
+		if (inode->data.file_ext.file_size > 0x0FFFFFFFFUL)
+			return 0;
+		if (inode->data.file_ext.sparse > 0)
+			return 0;
+		if (inode->data.file_ext.nlink > 1)
+			return 0;
+
+		inode->data.file = temp;
+		break;
+	}
+	case SQFS_INODE_EXT_SLINK:
+	case SQFS_INODE_EXT_BDEV:
+	case SQFS_INODE_EXT_CDEV:
+	case SQFS_INODE_EXT_FIFO:
+	case SQFS_INODE_EXT_SOCKET:
+		break;
+	default:
+		return SQFS_ERROR_CORRUPTED;
+	}
+
+	inode->base.type = inverse_type[inode->base.type];
+	return 0;
+}
+
+int sqfs_inode_set_file_size(sqfs_inode_generic_t *inode, uint64_t size)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		inode->data.file_ext.file_size = size;
+
+		if (size < 0x0FFFFFFFFUL)
+			sqfs_inode_make_basic(inode);
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		if (size > 0x0FFFFFFFFUL) {
+			sqfs_inode_make_extended(inode);
+			inode->data.file_ext.file_size = size;
+		} else {
+			inode->data.file.file_size = size;
+		}
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_set_frag_location(sqfs_inode_generic_t *inode,
+				 uint32_t index, uint32_t offset)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		inode->data.file_ext.fragment_idx = index;
+		inode->data.file_ext.fragment_offset = offset;
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		inode->data.file.fragment_index = index;
+		inode->data.file.fragment_offset = offset;
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_set_file_block_start(sqfs_inode_generic_t *inode,
+				    uint64_t location)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		inode->data.file_ext.blocks_start = location;
+
+		if (location < 0x0FFFFFFFFUL)
+			sqfs_inode_make_basic(inode);
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		if (location > 0x0FFFFFFFFUL) {
+			sqfs_inode_make_extended(inode);
+			inode->data.file_ext.blocks_start = location;
+		} else {
+			inode->data.file.blocks_start = location;
+		}
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_get_file_size(const sqfs_inode_generic_t *inode, uint64_t *size)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		*size = inode->data.file_ext.file_size;
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		*size = inode->data.file.file_size;
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_get_frag_location(const sqfs_inode_generic_t *inode,
+				 uint32_t *index, uint32_t *offset)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		*index = inode->data.file_ext.fragment_idx;
+		*offset = inode->data.file_ext.fragment_offset;
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		*index = inode->data.file.fragment_index;
+		*offset = inode->data.file.fragment_offset;
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
+
+int sqfs_inode_get_file_block_start(const sqfs_inode_generic_t *inode,
+				    uint64_t *location)
+{
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		*location = inode->data.file_ext.blocks_start;
+	} else if (inode->base.type == SQFS_INODE_FILE) {
+		*location = inode->data.file.blocks_start;
+	} else {
+		return SQFS_ERROR_NOT_FILE;
+	}
+
+	return 0;
+}
diff --git a/lib/sqfshelper/data_reader_dump.c b/lib/sqfshelper/data_reader_dump.c
index e28bf20..a9b6bb9 100644
--- a/lib/sqfshelper/data_reader_dump.c
+++ b/lib/sqfshelper/data_reader_dump.c
@@ -25,11 +25,7 @@ int sqfs_data_reader_dump(sqfs_data_reader_t *data,
 	size_t i, diff;
 	int err;
 
-	if (inode->base.type == SQFS_INODE_EXT_FILE) {
-		filesz = inode->data.file_ext.file_size;
-	} else {
-		filesz = inode->data.file.file_size;
-	}
+	sqfs_inode_get_file_size(inode, &filesz);
 
 	if (allow_sparse && ftruncate(outfd, filesz))
 		goto fail_sparse;
diff --git a/tar/sqfs2tar.c b/tar/sqfs2tar.c
index 0bacd0e..1afbedf 100644
--- a/tar/sqfs2tar.c
+++ b/tar/sqfs2tar.c
@@ -195,27 +195,7 @@ static int get_xattrs(const sqfs_inode_generic_t *inode, tar_xattr_t **out)
 	if (xr == NULL)
 		return 0;
 
-	switch (inode->base.type) {
-	case SQFS_INODE_EXT_DIR:
-		index = inode->data.dir_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_FILE:
-		index = inode->data.file_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_SLINK:
-		index = inode->data.slink_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_BDEV:
-	case SQFS_INODE_EXT_CDEV:
-		index = inode->data.dev_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_FIFO:
-	case SQFS_INODE_EXT_SOCKET:
-		index = inode->data.ipc_ext.xattr_idx;
-		break;
-	default:
-		return 0;
-	}
+	sqfs_inode_get_xattr_index(inode, &index);
 
 	if (index == 0xFFFFFFFF)
 		return 0;
diff --git a/unpack/dump_xattrs.c b/unpack/dump_xattrs.c
index c619767..13bddfe 100644
--- a/unpack/dump_xattrs.c
+++ b/unpack/dump_xattrs.c
@@ -17,27 +17,7 @@ int dump_xattrs(sqfs_xattr_reader_t *xattr, const sqfs_inode_generic_t *inode)
 	if (xattr == NULL)
 		return 0;
 
-	switch (inode->base.type) {
-	case SQFS_INODE_EXT_DIR:
-		index = inode->data.dir_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_FILE:
-		index = inode->data.file_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_SLINK:
-		index = inode->data.slink_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_BDEV:
-	case SQFS_INODE_EXT_CDEV:
-		index = inode->data.dev_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_FIFO:
-	case SQFS_INODE_EXT_SOCKET:
-		index = inode->data.ipc_ext.xattr_idx;
-		break;
-	default:
-		return 0;
-	}
+	sqfs_inode_get_xattr_index(inode, &index);
 
 	if (index == 0xFFFFFFFF)
 		return 0;
diff --git a/unpack/fill_files.c b/unpack/fill_files.c
index 2c20ab0..3d1e7b2 100644
--- a/unpack/fill_files.c
+++ b/unpack/fill_files.c
@@ -15,80 +15,51 @@ static struct file_ent {
 static size_t num_files = 0, max_files = 0;
 static size_t block_size = 0;
 
-static uint32_t get_frag_idx(const sqfs_inode_generic_t *inode)
-{
-	if (inode->base.type == SQFS_INODE_EXT_FILE)
-		return inode->data.file_ext.fragment_idx;
-
-	return inode->data.file.fragment_index;
-}
-
-static uint32_t get_frag_off(const sqfs_inode_generic_t *inode)
-{
-	if (inode->base.type == SQFS_INODE_EXT_FILE)
-		return inode->data.file_ext.fragment_offset;
-
-	return inode->data.file.fragment_offset;
-}
-
-static uint64_t get_size(const sqfs_inode_generic_t *inode)
-{
-	if (inode->base.type == SQFS_INODE_EXT_FILE)
-		return inode->data.file_ext.file_size;
-
-	return inode->data.file.file_size;
-}
-
-static uint64_t get_start(const sqfs_inode_generic_t *inode)
-{
-	if (inode->base.type == SQFS_INODE_EXT_FILE)
-		return inode->data.file_ext.blocks_start;
-
-	return inode->data.file.blocks_start;
-}
-
-static bool has_fragment(const struct file_ent *ent)
-{
-	if (get_size(ent->inode) % block_size == 0)
-		return false;
-
-	return get_frag_off(ent->inode) < block_size &&
-		(get_frag_idx(ent->inode) != 0xFFFFFFFF);
-}
-
 static int compare_files(const void *l, const void *r)
 {
+	uint32_t lhs_frag_idx, lhs_frag_off, rhs_frag_idx, rhs_frag_off;
+	uint64_t lhs_size, rhs_size, lhs_start, rhs_start;
 	const struct file_ent *lhs = l, *rhs = r;
 
+	sqfs_inode_get_frag_location(lhs->inode, &lhs_frag_idx, &lhs_frag_off);
+	sqfs_inode_get_file_block_start(lhs->inode, &lhs_start);
+	sqfs_inode_get_file_size(lhs->inode, &lhs_size);
+
+	sqfs_inode_get_frag_location(rhs->inode, &rhs_frag_idx, &rhs_frag_off);
+	sqfs_inode_get_file_block_start(rhs->inode, &rhs_start);
+	sqfs_inode_get_file_size(rhs->inode, &rhs_size);
+
 	/* Files with fragments come first, ordered by ID.
 	   In case of tie, files without data blocks come first,
 	   and the others are ordered by start block. */
-	if (has_fragment(lhs)) {
-		if (!(has_fragment(rhs)))
+	if ((lhs_size % block_size) && (lhs_frag_off < block_size) &&
+	    (lhs_frag_idx != 0xFFFFFFFF)) {
+		if ((rhs_size % block_size) && (rhs_frag_off < block_size) &&
+		    (rhs_frag_idx != 0xFFFFFFFF))
 			return -1;
 
-		if (get_frag_idx(lhs->inode) < get_frag_idx(rhs->inode))
+		if (lhs_frag_idx < rhs_frag_idx)
 			return -1;
 
-		if (get_frag_idx(lhs->inode) > get_frag_idx(rhs->inode))
+		if (lhs_frag_idx > rhs_frag_idx)
 			return 1;
 
-		if (get_size(lhs->inode) < block_size)
-			return (get_size(rhs->inode) < block_size) ? 0 : -1;
+		if (lhs_size < block_size)
+			return (rhs_size < block_size) ? 0 : -1;
 
-		if (get_size(rhs->inode) < block_size)
+		if (rhs_size < block_size)
 			return 1;
 
 		goto order_by_start;
 	}
 
-	if (has_fragment(rhs))
+	if ((rhs_size % block_size) && (rhs_frag_off < block_size) &&
+	    (rhs_frag_idx != 0xFFFFFFFF))
 		return 1;
 
 	/* order the rest by start block */
 order_by_start:
-	return get_start(lhs->inode) < get_start(rhs->inode) ? -1 :
-		get_start(lhs->inode) > get_start(rhs->inode) ? 1 : 0;
+	return lhs_start < rhs_start ? -1 : lhs_start > rhs_start ? 1 : 0;
 }
 
 static int add_file(const sqfs_tree_node_t *node)
diff --git a/unpack/list_files.c b/unpack/list_files.c
index 11e18cb..ae259bd 100644
--- a/unpack/list_files.c
+++ b/unpack/list_files.c
@@ -87,13 +87,12 @@ static void print_node_size(const sqfs_tree_node_t *n, char *buffer)
 	case S_IFLNK:
 		print_size(strlen(n->inode->slink_target), buffer);
 		break;
-	case S_IFREG:
-		if (n->inode->base.type == SQFS_INODE_EXT_FILE) {
-			print_size(n->inode->data.file_ext.file_size, buffer);
-		} else {
-			print_size(n->inode->data.file.file_size, buffer);
-		}
+	case S_IFREG: {
+		uint64_t size;
+		sqfs_inode_get_file_size(n->inode, &size);
+		print_size(size, buffer);
 		break;
+	}
 	case S_IFDIR:
 		if (n->inode->base.type == SQFS_INODE_EXT_DIR) {
 			print_size(n->inode->data.dir_ext.size, buffer);
diff --git a/unpack/restore_fstree.c b/unpack/restore_fstree.c
index afa4abb..5b82de4 100644
--- a/unpack/restore_fstree.c
+++ b/unpack/restore_fstree.c
@@ -101,27 +101,7 @@ static int set_xattr(sqfs_xattr_reader_t *xattr, const sqfs_tree_node_t *n)
 	size_t i;
 	int ret;
 
-	switch (n->inode->base.type) {
-	case SQFS_INODE_EXT_DIR:
-		index = n->inode->data.dir_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_FILE:
-		index = n->inode->data.file_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_SLINK:
-		index = n->inode->data.slink_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_BDEV:
-	case SQFS_INODE_EXT_CDEV:
-		index = n->inode->data.dev_ext.xattr_idx;
-		break;
-	case SQFS_INODE_EXT_FIFO:
-	case SQFS_INODE_EXT_SOCKET:
-		index = n->inode->data.ipc_ext.xattr_idx;
-		break;
-	default:
-		return 0;
-	}
+	sqfs_inode_get_xattr_index(n->inode, &index);
 
 	if (index == 0xFFFFFFFF)
 		return 0;