erofs-utils: introduce dump.erofs to erofs-utils

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AUTHORS

+EROFS USERSPACE UTILITIES
+M: Li Guifu <bluce.liguifu@huawei.com>
+M: Miao Xie <miaoxie@huawei.com>
+M: Fang Wei <fangwei1@huawei.com>
+R: Gao Xiang <xiang@kernel.org>
+R: Chao Yu <yuchao0@huawei.com>
+S: Maintained
+L: linux-erofs@lists.ozlabs.org
+

COPYING

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ChangeLog

+erofs-utils 1.3
+
+ * This release includes the following updates:
+   - support new big pcluster feature together with Linux 5.13+;
+   - optimize buffer allocation logic (Hu Weiwen);
+   - optimize build performance for large directories (Hu Weiwen);
+   - add support to override uid / gid (Hu Weiwen);
+   - add support to adjust lz4 history window size (Huang Jianan);
+   - add a manual for erofsfuse;
+   - add support to limit max decompressed extent size;
+   - various bugfixes and cleanups;
+
+ -- Gao Xiang <xiang@kernel.org>  Tue, 01 Jun 2021 00:00:00 +0800
+
+erofs-utils (1.2.1-1) unstable; urgency=medium
+
+ * A quick maintenance release includes the following updates:
+   - fix reported build issues due to different configurations;
+   - (mkfs.erofs, AOSP) fix sub-directory prefix for canned fs_config;
+   - update some obsoleted email address;
+
+ -- Gao Xiang <xiang@kernel.org>  Sun, 10 Jan 2021 00:00:00 +0800
+
+erofs-utils (1.2-1) unstable; urgency=medium
+
+ * This release includes the following features and bugfixes:
+   - (mkfs.erofs) support selinux file contexts;
+   - (mkfs.erofs) support $SOURCE_DATE_EPOCH;
+   - (mkfs.erofs) support a pre-defined UUID;
+   - (mkfs.erofs) fix random padding for reproducable builds;
+   - (mkfs.erofs) several fixes around hard links;
+   - (mkfs.erofs) minor code cleanups;
+   - (mkfs.erofs, AOSP) support Android fs_config;
+   - (experimental, disabled by default) add erofsfuse approach;
+
+ -- Gao Xiang <xiang@kernel.org>  Sun, 06 Dec 2020 00:00:00 +0800
+
+erofs-utils (1.1-1) unstable; urgency=low
+
+ * a maintenance release includes the following updates:
+   - (mkfs.erofs) add a manual for mkfs.erofs;
+   - (mkfs.erofs) add superblock checksum support;
+   - (mkfs.erofs) add filesystem UUID support;
+   - (mkfs.erofs) add exclude files support;
+   - (mkfs.erofs) fix compiling issues under specific conditions;
+   - (mkfs.erofs) minor code cleanups;
+
+ -- Gao Xiang <xiang@kernel.org>  Tue, 14 Apr 2020 00:00:00 +0800
+
+erofs-utils (1.0-1) unstable; urgency=low
+
+ * first release with the following new features:
+   - (mkfs.erofs) uncompressed file support;
+   - (mkfs.erofs) uncompressed tail-end packing inline data support;
+   - (mkfs.erofs) lz4 / lz4HC compressed file support;
+   - (mkfs.erofs) special file support;
+   - (mkfs.erofs) inline / shared xattrs support;
+   - (mkfs.erofs) Posix ACL support;
+
+ -- Gao Xiang <xiang@kernel.org>  Thu, 24 Oct 2019 00:00:00 +0800
+

README

+erofs-utils
+===========
+
+erofs-utils includes user-space tools for EROFS filesystem.
+Currently mkfs.erofs and erofsfuse (experimental) are available.
+
+Dependencies & build
+--------------------
+
+ lz4 1.8.0+ for lz4 enabled [2], lz4 1.9.3+ highly recommended [4][5].
+
+ libfuse 2.6+ for erofsfuse enabled as a plus.
+
+How to build for lz4-1.9.0 or above
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+To build, you can run the following commands in order:
+
+::
+
+	$ ./autogen.sh
+	$ ./configure
+	$ make
+
+mkfs.erofs binary will be generated under mkfs folder.
+
+* For lz4 < 1.9.2, there are some stability issues about
+  LZ4_compress_destSize(). (lz4hc isn't impacted) [3].
+
+** For lz4 = 1.9.2, there is a noticeable regression about
+   LZ4_decompress_safe_partial() [5], which impacts erofsfuse
+   functionality for legacy images (without 0PADDING).
+
+How to build for lz4-1.8.0~1.8.3
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+For these old lz4 versions, lz4hc algorithm cannot be supported
+without lz4-static installed due to LZ4_compress_HC_destSize()
+unstable api usage, which means lz4 will only be available if
+lz4-static isn't found.
+
+On Fedora, lz4-static can be installed by using:
+
+	yum install lz4-static.x86_64
+
+However, it's still not recommended using those versions directly
+since there are serious bugs in these compressors, see [2] [3] [4]
+as well.
+
+mkfs.erofs
+----------
+
+two main kinds of EROFS images can be generated: (un)compressed.
+
+ - For uncompressed images, there will be none of compression
+   files in these images. However, it can decide whether the tail
+   block of a file should be inlined or not properly [1].
+
+ - For compressed images, it will try to use lz4(hc) algorithm
+   first for each regular file and see if storage space can be
+   saved with compression. If not, fallback to an uncompressed
+   file.
+
+How to generate EROFS images (Linux 5.3+)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Currently lz4 and lz4hc are available for compression, e.g.
+ $ mkfs.erofs -zlz4hc foo.erofs.img foo/
+
+Or leave all files uncompressed as an option:
+ $ mkfs.erofs foo.erofs.img foo/
+
+In addition, you could specify a higher compression level to get a
+(slightly) better compression ratio than the default level, e.g.
+ $ mkfs.erofs -zlz4hc,12 foo.erofs.img foo/
+
+How to generate EROFS big pcluster images (Linux 5.13+)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In order to get much better compression ratios (thus better sequential
+read performance for common storage devices), big pluster feature has
+been introduced since linux-5.13, which is not forward-compatible with
+old kernels.
+
+In details, -C is used to specify the maximum size of each big pcluster
+in bytes, e.g.
+ $ mkfs.erofs -zlz4hc -C65536 foo.erofs.img foo/
+
+So in that case, pcluster size can be 64KiB at most.
+
+Note that large pcluster size can cause bad random performance, so
+please evaluate carefully in advance. Or make your own per-(sub)file
+compression strategies according to file access patterns if needed.
+
+How to generate legacy EROFS images (Linux 4.19+)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Decompression inplace and compacted indexes have been introduced in
+linux-5.3, which are not forward-compatible with older kernels.
+
+In order to generate _legacy_ EROFS images for old kernels,
+consider adding "-E legacy-compress" to the command line, e.g.
+
+ $ mkfs.erofs -E legacy-compress -zlz4hc foo.erofs.img foo/
+
+For Linux kernel >= 5.3, legacy EROFS images are _NOT recommended_
+due to runtime performance loss compared with non-legacy images.
+
+Obsoleted erofs.mkfs
+~~~~~~~~~~~~~~~~~~~~
+
+There is an original erofs.mkfs version developed by Li Guifu,
+which was replaced by the new erofs-utils implementation.
+
+git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs-utils.git -b obsoleted_mkfs
+
+PLEASE NOTE: This version is highly _NOT recommended_ now.
+
+erofsfuse (experimental, unstable)
+----------------------------------
+
+erofsfuse is introduced to support EROFS format for various platforms
+(including older linux kernels) and new on-disk features iteration.
+It can also be used as an unpacking tool for unprivileged users.
+
+It supports fixed-sized output decompression *without* any in-place
+I/O or in-place decompression optimization. Also like the other FUSE
+implementations, it suffers from most common performance issues (e.g.
+significant I/O overhead, double caching, etc.)
+
+Therefore, NEVER use it if performance is the top concern.
+
+Note that xattr & ACL aren't implemented yet due to the current Android
+use-case vs limited time. If you have some interest, contribution is,
+as always, welcome.
+
+How to build erofsfuse
+~~~~~~~~~~~~~~~~~~~~~~
+
+It's disabled by default as an experimental feature for now, to enable
+and build it manually:
+
+	$ ./configure --enable-fuse
+	$ make
+
+erofsfuse binary will be generated under fuse folder.
+
+How to mount an EROFS image with erofsfuse
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+As the other FUSE implementations, it's quite simple to mount with
+erofsfuse, e.g.:
+ $ erofsfuse foo.erofs.img foo/
+
+Alternatively, to make it run in foreground (with debugging level 3):
+ $ erofsfuse -f --dbglevel=3 foo.erofs.img foo/
+
+To debug erofsfuse (also automatically run in foreground):
+ $ erofsfuse -d foo.erofs.img foo/
+
+To unmount an erofsfuse mountpoint as a non-root user:
+ $ fusermount -u foo/
+
+Contribution
+------------
+
+erofs-utils is under GPLv2+ as a part of EROFS filesystem project,
+feel free to send patches or feedback to us.
+
+To:
+  linux-erofs mailing list   <linux-erofs@lists.ozlabs.org>
+  Li Guifu                   <bluce.liguifu@huawei.com>
+  Miao Xie                   <miaoxie@huawei.com>
+  Fang Wei                   <fangwei1@huawei.com>
+
+Cc:
+  Gao Xiang                  <xiang@kernel.org>
+  Chao Yu                    <yuchao0@huawei.com>
+
+Comments
+--------
+
+[1] According to the EROFS on-disk format, the tail block of files
+    could be inlined aggressively with its metadata in order to reduce
+    the I/O overhead and save the storage space (called tail-packing).
+
+[2] There was a bug until lz4-1.8.3, which can crash erofs-utils
+    randomly. Fortunately bugfix by our colleague Qiuyang Sun was
+    merged in lz4-1.9.0.
+
+    For more details, please refer to
+    https://github.com/lz4/lz4/commit/660d21272e4c8a0f49db5fc1e6853f08713dff82
+
+[3] There were many bugfixes merged into lz4-1.9.2 for
+    LZ4_compress_destSize(), and I once ran into some crashs due to
+    those issues. * Again lz4hc is not affected. *
+
+    [LZ4_compress_destSize] Allow 2 more bytes of match length
+    https://github.com/lz4/lz4/commit/690009e2c2f9e5dcb0d40e7c0c40610ce6006eda
+
+    [LZ4_compress_destSize] Fix rare data corruption bug
+    https://github.com/lz4/lz4/commit/6bc6f836a18d1f8fd05c8fc2b42f1d800bc25de1
+
+    [LZ4_compress_destSize] Fix overflow condition
+    https://github.com/lz4/lz4/commit/13a2d9e34ffc4170720ce417c73e396d0ac1471a
+
+    [LZ4_compress_destSize] Fix off-by-one error in fix
+    https://github.com/lz4/lz4/commit/7c32101c655d93b61fc212dcd512b87119dd7333
+
+    [LZ4_compress_destSize] Fix off-by-one error
+    https://github.com/lz4/lz4/commit/d7cad81093cd805110291f84d64d385557d0ffba
+
+    since upstream lz4 doesn't have stable branch for old versions, it's
+    preferred to use latest upstream lz4 library (although some regressions
+    could happen since new features are also introduced to latest upstream
+    version as well) or backport all stable bugfixes to old stable versions,
+    e.g. our unofficial lz4 fork: https://github.com/erofs/lz4
+
+[4] LZ4HC didn't compress long zeroed buffer properly with
+    LZ4_compress_HC_destSize()
+    https://github.com/lz4/lz4/issues/784
+
+    which has been resolved in
+    https://github.com/lz4/lz4/commit/e7fe105ac6ed02019d34731d2ba3aceb11b51bb1
+
+    and already included in lz4-1.9.3, see:
+    https://github.com/lz4/lz4/releases/tag/v1.9.3
+
+[5] LZ4_decompress_safe_partial is broken in 1.9.2
+    https://github.com/lz4/lz4/issues/783
+
+    which is also resolved in lz4-1.9.3.
+

dump/Makefile.am

+# SPDX-License-Identifier: GPL-2.0+
+# Makefile.am
+
+AUTOMAKE_OPTIONS = foreign
+bin_PROGRAMS     = dump.erofs
+AM_CPPFLAGS = ${libuuid_CFLAGS}
+dump_erofs_SOURCES = main.c
+dump_erofs_CFLAGS = -Wall -Werror -I$(top_srcdir)/include
+dump_erofs_LDADD = $(top_builddir)/lib/liberofs.la ${libuuid_LIBS} ${liblz4_LIBS}
\ No newline at end of file

dump/main.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021-2022 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Wang Qi <mpiglet@outlook.com>
+ *            Guo Xuenan <guoxuenan@huawei.com>
+ */
+
+#include <stdlib.h>
+#include <getopt.h>
+#include <sys/sysmacros.h>
+#include <time.h>
+#include "erofs/print.h"
+#include "erofs/io.h"
+
+#ifdef HAVE_LIBUUID
+#include <uuid.h>
+#endif
+
+struct dumpcfg {
+	bool print_superblock;
+	bool print_inode;
+	bool print_statistic;
+	bool print_inode_phy;
+	bool print_version;
+	u64 ino;
+	u64 ino_phy;
+};
+static struct dumpcfg dumpcfg;
+
+static const char chart_format[] = "%-16s	%-11d %8.2f%% |%-50s|\n";
+static const char header_format[] = "%-16s %11s %16s |%-50s|\n";
+static char *file_types[] = {
+	".so", ".png", ".jpg", ".xml", ".html", ".odex",
+	".vdex", ".apk", ".ttf", ".jar", ".json", ".ogg",
+	".oat", ".art", ".rc", ".otf", ".txt", "others",
+};
+#define OTHERFILETYPE	ARRAY_SIZE(file_types)
+/* (1 << FILE_MAX_SIZE_BITS)KB */
+#define	FILE_MAX_SIZE_BITS	16
+
+static const char * const file_category_types[] = {
+	[EROFS_FT_UNKNOWN] = "unknown type",
+	[EROFS_FT_REG_FILE] = "regular file",
+	[EROFS_FT_DIR] = "directory",
+	[EROFS_FT_CHRDEV] = "char dev",
+	[EROFS_FT_BLKDEV] = "block dev",
+	[EROFS_FT_FIFO] = "FIFO file",
+	[EROFS_FT_SOCK] = "SOCK file",
+	[EROFS_FT_SYMLINK] = "symlink file",
+};
+
+struct statistics {
+	unsigned long files;
+	unsigned long compressed_files;
+	unsigned long uncompressed_files;
+	unsigned long files_total_size;
+	unsigned long files_total_origin_size;
+	double compress_rate;
+
+	/* statistics the number of files based on inode_info->flags */
+	unsigned long file_category_stat[EROFS_FT_MAX];
+	/* statistics the number of files based on file name extensions */
+	unsigned int file_type_stat[OTHERFILETYPE];
+	/* statistics the number of files based on file orignial size */
+	unsigned int file_original_size[FILE_MAX_SIZE_BITS + 1];
+	/* statistics the number of files based on the compressed
+	 * size of file
+	 */
+	unsigned int file_comp_size[FILE_MAX_SIZE_BITS + 1];
+};
+static struct statistics stats;
+
+static struct option long_options[] = {
+	{"help", no_argument, 0, 1},
+	{0, 0, 0, 0},
+};
+
+struct feature {
+	bool compat;
+	__le32 flag;
+	const char *name;
+};
+
+static struct feature feature_lists[] = {
+	{ true, EROFS_FEATURE_COMPAT_SB_CHKSUM, "sb_csum" },
+	{ false, EROFS_FEATURE_INCOMPAT_LZ4_0PADDING, "0padding" },
+	{ false, EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER, "bigpcluster" },
+};
+
+static void usage(void)
+{
+	fputs("usage: [options] IMAGE\n\n"
+		"Dump erofs layout from IMAGE, and [options] are:\n"
+		"-s      print information about superblock\n"
+		"-i #    print target # inode info\n"
+		"-I #    print target # inode on-disk info\n"
+		"-S      print statistic information of the erofs-image\n"
+		"-V      print the version number of dump.erofs and exit.\n"
+		"--help  display this help and exit.\n",
+		stderr);
+}
+static void dumpfs_print_version(void)
+{
+	fprintf(stderr, "dump.erofs %s\n", cfg.c_version);
+}
+
+static int dumpfs_parse_options_cfg(int argc, char **argv)
+{
+	int opt;
+	u64 i;
+
+	while ((opt = getopt_long(argc, argv, "i:I:sSV",
+					long_options, NULL)) != -1) {
+		switch (opt) {
+		case 'i':
+			i = atoll(optarg);
+			dumpcfg.print_inode = true;
+			dumpcfg.ino = i;
+			break;
+		case 'I':
+			i = atoll(optarg);
+			dumpcfg.print_inode_phy = true;
+			dumpcfg.ino_phy = i;
+			break;
+		case 's':
+			dumpcfg.print_superblock = true;
+			break;
+		case 'S':
+			dumpcfg.print_statistic = true;
+			break;
+		case 'V':
+			dumpfs_print_version();
+			exit(0);
+		case 1:
+			usage();
+			exit(0);
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (optind >= argc)
+		return -EINVAL;
+
+	cfg.c_img_path = strdup(argv[optind++]);
+	if (!cfg.c_img_path)
+		return -ENOMEM;
+
+	if (optind < argc) {
+		erofs_err("unexpected argument: %s\n", argv[optind]);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int get_file_compressed_size(struct erofs_inode *inode,
+		erofs_off_t *size)
+{
+	*size = 0;
+	switch (inode->datalayout) {
+	case EROFS_INODE_FLAT_INLINE:
+	case EROFS_INODE_FLAT_PLAIN:
+		stats.uncompressed_files++;
+		*size = inode->i_size;
+		break;
+	case EROFS_INODE_FLAT_COMPRESSION_LEGACY:
+	case EROFS_INODE_FLAT_COMPRESSION:
+		stats.compressed_files++;
+		*size = inode->u.i_blocks * EROFS_BLKSIZ;
+		break;
+	default:
+		erofs_err("unknown datalayout");
+		return -1;
+	}
+	return 0;
+}
+
+static int get_path_by_nid(erofs_nid_t nid, erofs_nid_t parent_nid,
+		erofs_nid_t target, char *path, unsigned int pos)
+{
+	int err;
+	struct erofs_inode inode = {.nid = nid};
+	erofs_off_t offset;
+	char buf[EROFS_BLKSIZ];
+
+	path[pos++] = '/';
+	if (target == sbi.root_nid)
+		return 0;
+
+	err = erofs_read_inode_from_disk(&inode);
+	if (err) {
+		erofs_err("read inode %lu failed", nid);
+		return err;
+	}
+
+	offset = 0;
+	while (offset < inode.i_size) {
+		erofs_off_t maxsize = min_t(erofs_off_t,
+					inode.i_size - offset, EROFS_BLKSIZ);
+		struct erofs_dirent *de = (void *)buf;
+		struct erofs_dirent *end;
+		unsigned int nameoff;
+
+		err = erofs_pread(&inode, buf, maxsize, offset);
+		if (err)
+			return err;
+
+		nameoff = le16_to_cpu(de->nameoff);
+		if (nameoff < sizeof(struct erofs_dirent) ||
+		    nameoff >= PAGE_SIZE) {
+			erofs_err("invalid de[0].nameoff %u @ nid %llu",
+				  nameoff, nid | 0ULL);
+			return -EFSCORRUPTED;
+		}
+
+		end = (void *)buf + nameoff;
+		while (de < end) {
+			const char *dname;
+			unsigned int dname_len;
+
+			nameoff = le16_to_cpu(de->nameoff);
+			dname = (char *)buf + nameoff;
+			if (de + 1 >= end)
+				dname_len = strnlen(dname, maxsize - nameoff);
+			else
+				dname_len = le16_to_cpu(de[1].nameoff)
+					- nameoff;
+
+			/* a corrupted entry is found */
+			if (nameoff + dname_len > maxsize ||
+			    dname_len > EROFS_NAME_LEN) {
+				erofs_err("bogus dirent @ nid %llu",
+						le64_to_cpu(de->nid) | 0ULL);
+				DBG_BUGON(1);
+				return -EFSCORRUPTED;
+			}
+
+			if (de->nid == target) {
+				memcpy(path + pos, dname, dname_len);
+				return 0;
+			}
+
+			if (de->file_type == EROFS_FT_DIR &&
+					de->nid != parent_nid &&
+					de->nid != nid) {
+				memcpy(path + pos, dname, dname_len);
+				err = get_path_by_nid(de->nid, nid,
+						target, path, pos + dname_len);
+				if (!err)
+					return 0;
+				memset(path + pos, 0, dname_len);
+			}
+			++de;
+		}
+		offset += maxsize;
+	}
+	return -1;
+}
+
+static void dumpfs_print_inode_phy(void)
+{
+	int err;
+	erofs_nid_t nid = dumpcfg.ino_phy;
+	struct erofs_inode inode = {.nid = nid};
+	char path[PATH_MAX + 1] = {0};
+
+	err = erofs_read_inode_from_disk(&inode);
+	if (err < 0) {
+		erofs_err("read inode %lu from disk failed", nid);
+		return;
+	}
+
+	const erofs_off_t ibase = iloc(inode.nid);
+	const erofs_off_t pos = Z_EROFS_VLE_LEGACY_INDEX_ALIGN(
+			ibase + inode.inode_isize + inode.xattr_isize);
+	erofs_blk_t blocks = inode.u.i_blocks;
+	erofs_blk_t start = 0;
+	erofs_blk_t end = 0;
+	unsigned int extent_count;
+	struct erofs_map_blocks map = {
+		.index = UINT_MAX,
+		.m_la = 0,
+	};
+
+	fprintf(stdout, "Inode %lu on-disk info:\n", nid);
+	err = get_path_by_nid(sbi.root_nid, sbi.root_nid, nid, path, 0);
+	if (!err)
+		fprintf(stderr, "File path: %s\n", path);
+	else
+		erofs_err("path not found");
+	fprintf(stdout, "File size: %lu\n", inode.i_size);
+
+	switch (inode.datalayout) {
+	case EROFS_INODE_FLAT_INLINE:
+	case EROFS_INODE_FLAT_PLAIN:
+		if (inode.u.i_blkaddr == NULL_ADDR)
+			start = end = erofs_blknr(pos);
+		else {
+			start = inode.u.i_blkaddr;
+			end = start + BLK_ROUND_UP(inode.i_size) - 1;
+		}
+		fprintf(stdout, "Plain blknr: %u - %u\n", start, end);
+		break;
+
+	case EROFS_INODE_FLAT_COMPRESSION_LEGACY:
+	case EROFS_INODE_FLAT_COMPRESSION:
+		err = z_erofs_map_blocks_iter(&inode, &map, 0);
+		if (err)
+			erofs_err("get file blocks range failed");
+
+		start = erofs_blknr(map.m_pa);
+		end = start - 1 + blocks;
+		fprintf(stdout,
+				"Compressed blknr: %u - %u\n", start, end);
+		extent_count = 0;
+		map.m_la = 0;
+		while (map.m_la < inode.i_size) {
+			err = z_erofs_map_blocks_iter(&inode, &map,
+					EROFS_GET_BLOCKS_FIEMAP);
+			fprintf(stdout, "Extent %u:\n", extent_count++);
+			fprintf(stdout, "on-disk blkaddr/length: 0x%08lx/0x%04lx\n",
+					map.m_pa, map.m_plen);
+			fprintf(stdout, "logical offset/length:  0x%08lx/0x%04lx\n",
+					map.m_la, map.m_llen);
+			map.m_la += map.m_llen;
+		}
+
+		break;
+	}
+}
+
+static void dumpfs_print_inode(void)
+{
+	int err;
+	erofs_off_t size;
+	u16 access_mode;
+	time_t t;
+	erofs_nid_t nid = dumpcfg.ino;
+	struct erofs_inode inode = {.nid = nid};
+	char path[PATH_MAX + 1] = {0};
+	char access_mode_str[] = "rwxrwxrwx";
+
+	err = erofs_read_inode_from_disk(&inode);
+	if (err) {
+		erofs_err("read inode %lu from disk failed", nid);
+		return;
+	}
+
+	err = get_file_compressed_size(&inode, &size);
+	if (err) {
+		erofs_err("get file size failed\n");
+		return;
+	}
+
+	fprintf(stdout, "Inode %lu on-disk info:\n", dumpcfg.ino);
+	err = get_path_by_nid(sbi.root_nid, sbi.root_nid, nid, path, 0);
+
+	fprintf(stdout, "File path:            %s\n",
+			!err ? path : "path not found");
+	fprintf(stdout, "File nid:             %lu\n", inode.nid);
+	fprintf(stdout, "File inode core size: %d\n", inode.inode_isize);
+	fprintf(stdout, "File original size:   %lu\n", inode.i_size);
+	fprintf(stdout,	"File on-disk size:    %lu\n", size);
+	fprintf(stdout, "File compress rate:   %.2f%%\n",
+			(double)(100 * size) / (double)(inode.i_size));
+	fprintf(stdout, "File extent size:     %u\n", inode.extent_isize);
+	fprintf(stdout,	"File xattr size:      %u\n", inode.xattr_isize);
+	fprintf(stdout, "File type:            ");
+	switch (inode.i_mode & S_IFMT) {
+	case S_IFBLK:  fprintf(stdout, "block device\n");     break;
+	case S_IFCHR:  fprintf(stdout, "character device\n"); break;
+	case S_IFDIR:  fprintf(stdout, "directory\n");        break;
+	case S_IFIFO:  fprintf(stdout, "FIFO/pipe\n");        break;
+	case S_IFLNK:  fprintf(stdout, "symlink\n");          break;
+	case S_IFREG:  fprintf(stdout, "regular file\n");     break;
+	case S_IFSOCK: fprintf(stdout, "socket\n");           break;
+	default:       fprintf(stdout, "unknown?\n");         break;
+	}
+
+	access_mode = inode.i_mode & 0777;
+	t = inode.i_ctime;
+	for (int i = 8; i >= 0; i--)
+		if (((access_mode >> i) & 1) == 0)
+			access_mode_str[8 - i] = '-';
+	fprintf(stdout, "File access:          %04o/%s\n",
+			access_mode, access_mode_str);
+	fprintf(stdout, "File uid:             %u\n", inode.i_uid);
+	fprintf(stdout, "File gid:             %u\n", inode.i_gid);
+	fprintf(stdout, "File datalayout:      %d\n", inode.datalayout);
+	fprintf(stdout,	"File nlink:           %u\n", inode.i_nlink);
+	fprintf(stdout, "File create time:     %s", ctime(&t));
+	fprintf(stdout, "File access time:     %s", ctime(&t));
+	fprintf(stdout, "File modify time:     %s", ctime(&t));
+}
+
+static int get_file_type(const char *filename)
+{
+	char *postfix = strrchr(filename, '.');
+	int type = 0;
+
+	if (postfix == NULL)
+		return OTHERFILETYPE - 1;
+	while (type < OTHERFILETYPE - 1) {
+		if (strcmp(postfix, file_types[type]) == 0)
+			break;
+		type++;
+	}
+	return type;
+}
+
+static void update_file_size_statatics(erofs_off_t occupied_size,
+		erofs_off_t original_size)
+{
+	int occupied_size_mark;
+	int original_size_mark;
+
+	original_size_mark = 0;
+	occupied_size_mark = 0;
+	occupied_size >>= 10;
+	original_size >>= 10;
+
+	while (occupied_size || original_size) {
+		if (occupied_size) {
+			occupied_size >>= 1;
+			occupied_size_mark++;
+		}
+		if (original_size) {
+			original_size >>= 1;
+			original_size_mark++;
+		}
+	}
+
+	if (original_size_mark >= FILE_MAX_SIZE_BITS)
+		stats.file_original_size[FILE_MAX_SIZE_BITS]++;
+	else
+		stats.file_original_size[original_size_mark]++;
+
+	if (occupied_size_mark >= FILE_MAX_SIZE_BITS)
+		stats.file_comp_size[FILE_MAX_SIZE_BITS]++;
+	else
+		stats.file_comp_size[occupied_size_mark]++;
+}
+
+static int erofs_read_dir(erofs_nid_t nid, erofs_nid_t parent_nid)
+{
+	struct erofs_inode vi = { .nid = nid};
+	int err;
+	char buf[EROFS_BLKSIZ];
+	erofs_off_t offset;
+
+	err = erofs_read_inode_from_disk(&vi);
+	if (err)
+		return err;
+
+	offset = 0;
+	while (offset < vi.i_size) {
+		erofs_off_t maxsize = min_t(erofs_off_t,
+			vi.i_size - offset, EROFS_BLKSIZ);
+		struct erofs_dirent *de = (void *)buf;
+		struct erofs_dirent *end;
+		unsigned int nameoff;
+
+		err = erofs_pread(&vi, buf, maxsize, offset);
+		if (err)
+			return err;
+
+		nameoff = le16_to_cpu(de->nameoff);
+
+		if (nameoff < sizeof(struct erofs_dirent) ||
+		    nameoff >= PAGE_SIZE) {
+			erofs_err("invalid de[0].nameoff %u @ nid %llu",
+				  nameoff, nid | 0ULL);
+			return -EFSCORRUPTED;
+		}
+		end = (void *)buf + nameoff;
+		while (de < end) {
+			const char *dname;
+			unsigned int dname_len;
+			struct erofs_inode inode = { .nid = de->nid };
+			erofs_off_t occupied_size = 0;
+			/* skip "." and ".." dentry */
+			if (de->nid == nid || de->nid == parent_nid) {
+				de++;
+				continue;
+			}
+
+			nameoff = le16_to_cpu(de->nameoff);
+			dname = (char *)buf + nameoff;
+
+			if (de + 1 >= end)
+				dname_len = strnlen(dname, maxsize - nameoff);
+			else
+				dname_len = le16_to_cpu(de[1].nameoff) - nameoff;
+
+			/* a corrupted entry is found */
+			if (nameoff + dname_len > maxsize ||
+				dname_len > EROFS_NAME_LEN) {
+				erofs_err("bogus dirent @ nid %llu",
+						le64_to_cpu(de->nid) | 0ULL);
+				DBG_BUGON(1);
+				return -EFSCORRUPTED;
+			}
+
+			if (de->file_type >= EROFS_FT_MAX) {
+				erofs_err("invalid file type %llu", de->nid);
+				de++;
+				continue;
+			}
+			if (de->file_type != EROFS_FT_DIR)
+				stats.file_category_stat[de->file_type]++;
+
+			err = erofs_read_inode_from_disk(&inode);
+			if (err) {
+				erofs_err("read file inode from disk failed!");
+				return err;
+			}
+
+			stats.files++;
+			err = get_file_compressed_size(&inode, &occupied_size);
+			if (err) {
+				erofs_err("get file size failed\n");
+				return err;
+			}
+
+			switch (de->file_type) {
+			case EROFS_FT_REG_FILE:
+				stats.files_total_origin_size += inode.i_size;
+				stats.file_type_stat[get_file_type(dname)]++;
+				stats.files_total_size += occupied_size;
+				update_file_size_statatics(occupied_size, inode.i_size);
+				break;
+			case EROFS_FT_DIR:
+				if (de->nid != nid && de->nid != parent_nid) {
+					err = erofs_read_dir(de->nid, nid);
+					if (err) {
+						fprintf(stdout,
+								"parse dir nid %llu error occurred\n",
+								de->nid);
+						return err;
+					}
+					stats.file_category_stat[EROFS_FT_DIR]++;
+				}
+				break;
+			case EROFS_FT_UNKNOWN:
+			case EROFS_FT_CHRDEV:
+			case EROFS_FT_BLKDEV:
+			case EROFS_FT_FIFO:
+			case EROFS_FT_SOCK:
+			case EROFS_FT_SYMLINK:
+				break;
+			default:
+				erofs_err("%d file type not exists", de->file_type);
+			}
+			++de;
+		}
+		offset += maxsize;
+	}
+	return 0;
+}
+
+static void dumpfs_print_statistic_of_filetype(void)
+{
+	fprintf(stdout, "Filesystem total file count:		%lu\n",
+			stats.files);
+	for (int i = 0; i < EROFS_FT_MAX; i++)
+		fprintf(stdout, "Filesystem %s count:		%lu\n",
+			file_category_types[i], stats.file_category_stat[i]);
+}
+
+static void dumpfs_print_chart_row(char *col1, unsigned int col2,
+		double col3, char *col4)
+{
+	char row[500] = {0};
+
+	sprintf(row, chart_format, col1, col2, col3, col4);
+	fprintf(stdout, row);
+}
+
+static void dumpfs_print_chart_of_file(unsigned int *file_counts,
+		unsigned int len)
+{
+	char col1[30];
+	unsigned int col2;
+	double col3;
+	char col4[400];
+	unsigned int lowerbound = 0;
+	unsigned int upperbound = 1;
+
+	fprintf(stdout, header_format, ">=(KB) .. <(KB) ", "count",
+			"ratio", "distribution");
+	for (int i = 0; i < len; i++) {
+		memset(col1, 0, sizeof(col1));
+		memset(col4, 0, sizeof(col4));
+		if (i == len - 1)
+			sprintf(col1, "%6d ..", lowerbound);
+		else if (i <= 6)
+			sprintf(col1, "%6d .. %-6d", lowerbound, upperbound);
+		else
+
+			sprintf(col1, "%6d .. %-6d", lowerbound, upperbound);
+		col2 = file_counts[i];
+		col3 = (double)(100 * col2) / (double)stats.file_category_stat[EROFS_FT_REG_FILE];
+		memset(col4, '#', col3 / 2);
+		dumpfs_print_chart_row(col1, col2, col3, col4);
+		lowerbound = upperbound;
+		upperbound <<= 1;
+	}
+}
+
+static void dumpfs_print_chart_of_file_type(char **file_types, unsigned int len)
+{
+	char col1[30];
+	unsigned int col2;
+	double col3;
+	char col4[401];
+
+	fprintf(stdout, header_format, "type", "count", "ratio",
+			"distribution");
+	for (int i = 0; i < len; i++) {
+		memset(col1, 0, sizeof(col1));
+		memset(col4, 0, sizeof(col4));
+		sprintf(col1, "%-17s", file_types[i]);
+		col2 = stats.file_type_stat[i];
+		col3 = (double)(100 * col2) / (double)stats.file_category_stat[EROFS_FT_REG_FILE];
+		memset(col4, '#', col3 / 2);
+		dumpfs_print_chart_row(col1, col2, col3, col4);
+	}
+}
+
+static void dumpfs_print_statistic_of_compression(void)
+{
+	stats.compress_rate = (double)(100 * stats.files_total_size) /
+		(double)(stats.files_total_origin_size);
+	fprintf(stdout, "Filesystem compressed files:            %lu\n",
+			stats.compressed_files);
+	fprintf(stdout, "Filesystem uncompressed files:          %lu\n",
+			stats.uncompressed_files);
+	fprintf(stdout, "Filesystem total original file size:    %lu Bytes\n",
+			stats.files_total_origin_size);
+	fprintf(stdout, "Filesystem total file size:             %lu Bytes\n",
+			stats.files_total_size);
+	fprintf(stdout, "Filesystem compress rate:               %.2f%%\n",
+			stats.compress_rate);
+}
+
+static void dumpfs_print_statistic(void)
+{
+	int err;
+
+	err = erofs_read_dir(sbi.root_nid, sbi.root_nid);
+	if (err) {
+		erofs_err("read dir failed");
+		return;
+	}
+
+	dumpfs_print_statistic_of_filetype();
+	dumpfs_print_statistic_of_compression();
+
+	fprintf(stdout, "\nOriginal file size distribution:\n");
+	dumpfs_print_chart_of_file(stats.file_original_size,
+			ARRAY_SIZE(stats.file_original_size));
+	fprintf(stdout, "\nOn-Disk file size distribution:\n");
+	dumpfs_print_chart_of_file(stats.file_comp_size,
+			ARRAY_SIZE(stats.file_comp_size));
+	fprintf(stdout, "\nFile type distribution:\n");
+	dumpfs_print_chart_of_file_type(file_types, OTHERFILETYPE);
+}
+
+static void dumpfs_print_superblock(void)
+{
+	time_t time = sbi.build_time;
+	char uuid_str[37] = "not available";
+	int i = 0;
+
+	fprintf(stdout, "Filesystem magic number:                      0x%04X\n",
+			EROFS_SUPER_MAGIC_V1);
+	fprintf(stdout, "Filesystem blocks:                            %lu\n",
+			sbi.blocks);
+	fprintf(stdout, "Filesystem inode metadata start block:        %u\n",
+			sbi.meta_blkaddr);
+	fprintf(stdout, "Filesystem shared xattr metadata start block: %u\n",
+			sbi.xattr_blkaddr);
+	fprintf(stdout, "Filesystem root nid:                          %ld\n",
+			sbi.root_nid);
+	fprintf(stdout, "Filesystem inode count:                       %lu\n",
+			sbi.inos);
+	fprintf(stdout, "Filesystem created:                           %s",
+			ctime(&time));
+	fprintf(stdout, "Filesystem features:                          ");
+	for (; i < ARRAY_SIZE(feature_lists); i++) {
+		__le32 feature = feature_lists[i].compat ?
+			sbi.feature_compat : sbi.feature_incompat;
+		if (feature & feature_lists[i].flag)
+			fprintf(stdout, "%s ", feature_lists[i].name);
+	}
+#ifdef HAVE_LIBUUID
+	uuid_unparse_lower(sbi.uuid, uuid_str);
+#endif
+	fprintf(stdout, "\nFilesystem UUID:                              %s\n",
+			uuid_str);
+}
+
+int main(int argc, char **argv)
+{
+	int err = 0;
+
+	erofs_init_configure();
+	err = dumpfs_parse_options_cfg(argc, argv);
+	if (err) {
+		if (err == -EINVAL)
+			usage();
+		goto exit;
+	}
+
+	err = dev_open_ro(cfg.c_img_path);
+	if (err) {
+		erofs_err("open image file failed");
+		goto exit;
+	}
+
+	err = erofs_read_superblock();
+	if (err) {
+		erofs_err("read superblock failed");
+		goto exit;
+	}
+
+	if (dumpcfg.print_superblock)
+		dumpfs_print_superblock();
+
+	if (dumpcfg.print_statistic)
+		dumpfs_print_statistic();
+
+	if (dumpcfg.print_inode)
+		dumpfs_print_inode();
+
+	if (dumpcfg.print_inode_phy)
+		dumpfs_print_inode_phy();
+
+exit:
+	erofs_exit_configure();
+	return err;
+}

lib/inode.c

@@ -1214,4 +1214,4 @@ struct erofs_inode *erofs_dumpfs_build_tree_from_path(struct erofs_inode *parent
 	struct erofs_inode *inode = erofs_iget_from_img_path(path);
 	
 	
-}
+}
\ No newline at end of file