[RFC PATCH mtd-utils 057/110] fsck.ubifs: Add fsck support

From: Zhihao Cheng
Date: Fri Jun 07 2024 - 00:40:41 EST

Add basic process code for fsck.ubifs. There are following modes for fsck:
1. normal mode: Check the filesystem, ask user whether or not to fix
the problem as long as inconsistent data is found during fs checking.
2. safe mode: Check and safely repair the filesystem, if there are any
data dropping operations needed by fixing, fsck will fail.
3. danger mode: Answer 'yes' to all questions. There two sub modes:
a) Check and repair the filesystem according to TNC, data dropping
will be reported. If TNC/master/log is corrupted, fsck will fail.
b) Check and forcedly repair the filesystem according to TNC, turns
to rebuild filesystem if TNC/master/log is corrupted. Always make
fsck succeed.
4. check mode: Make no changes to the filesystem, only check the
filesystem.
5. rebuild mode: Scan entire UBI volume to find all nodes, and rebuild
filesystem, always make fsck success.

Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
---
.gitignore | 1 +
ubifs-utils/Makemodule.am | 12 ++
ubifs-utils/common/defs.h | 3 +-
ubifs-utils/fsck.ubifs/.gitignore | 1 +
ubifs-utils/fsck.ubifs/fsck.ubifs.c | 259 ++++++++++++++++++++++++++++++++++++
ubifs-utils/fsck.ubifs/fsck.ubifs.h | 91 +++++++++++++
ubifs-utils/libubifs/debug.c | 8 +-
ubifs-utils/libubifs/super.c | 52 ++++++++
ubifs-utils/libubifs/ubifs.h | 8 ++
9 files changed, 432 insertions(+), 3 deletions(-)
create mode 100644 ubifs-utils/fsck.ubifs/.gitignore
create mode 100644 ubifs-utils/fsck.ubifs/fsck.ubifs.c
create mode 100644 ubifs-utils/fsck.ubifs/fsck.ubifs.h

diff --git a/.gitignore b/.gitignore
index 8c51ee5f..3eb66c14 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,6 +30,7 @@ flash_otp_lock
flash_otp_write
flash_unlock
flashcp
+fsck.ubifs
ftl_check
ftl_format
jffs2dump
diff --git a/ubifs-utils/Makemodule.am b/ubifs-utils/Makemodule.am
index 936b49fc..0ed91dff 100644
--- a/ubifs-utils/Makemodule.am
+++ b/ubifs-utils/Makemodule.am
@@ -75,8 +75,20 @@ mkfs_ubifs_LDADD = libmtd.a libubi.a $(ZLIB_LIBS) $(LZO_LIBS) $(ZSTD_LIBS) $(UUI
mkfs_ubifs_CPPFLAGS = $(AM_CPPFLAGS) $(ZLIB_CFLAGS) $(LZO_CFLAGS) $(ZSTD_CFLAGS) $(UUID_CFLAGS) $(LIBSELINUX_CFLAGS) \
-I$(top_srcdir)/ubi-utils/include -I$(top_srcdir)/ubifs-utils/common -I $(top_srcdir)/ubifs-utils/libubifs -rdynamic

+fsck_ubifs_SOURCES = \
+ $(common_SOURCES) \
+ $(libubifs_SOURCES) \
+ ubifs-utils/fsck.ubifs/fsck.ubifs.h \
+ ubifs-utils/fsck.ubifs/fsck.ubifs.c
+
+fsck_ubifs_LDADD = libmtd.a libubi.a $(ZLIB_LIBS) $(LZO_LIBS) $(ZSTD_LIBS) $(UUID_LIBS) $(LIBSELINUX_LIBS) $(OPENSSL_LIBS) -lm -lpthread
+fsck_ubifs_CPPFLAGS = $(AM_CPPFLAGS) $(ZLIB_CFLAGS) $(LZO_CFLAGS) $(ZSTD_CFLAGS) $(UUID_CFLAGS) $(LIBSELINUX_CFLAGS) \
+ -I$(top_srcdir)/ubi-utils/include -I$(top_srcdir)/ubifs-utils/common -I $(top_srcdir)/ubifs-utils/libubifs \
+ -I$(top_srcdir)/ubifs-utils/fsck.ubifs -rdynamic
+
EXTRA_DIST += ubifs-utils/common/README ubifs-utils/libubifs/README

dist_sbin_SCRIPTS = ubifs-utils/mount.ubifs

sbin_PROGRAMS += mkfs.ubifs
+sbin_PROGRAMS += fsck.ubifs
diff --git a/ubifs-utils/common/defs.h b/ubifs-utils/common/defs.h
index 79451c40..8c8347a9 100644
--- a/ubifs-utils/common/defs.h
+++ b/ubifs-utils/common/defs.h
@@ -23,8 +23,9 @@ extern struct ubifs_info info_;
#include "common.h"

#define MKFS_PROGRAM_NAME "mkfs.ubifs"
+#define FSCK_PROGRAM_NAME "fsck.ubifs"

-enum { MKFS_PROGRAM_TYPE = 0 };
+enum { MKFS_PROGRAM_TYPE = 0, FSCK_PROGRAM_TYPE };

enum {
DUMP_PREFIX_NONE,
diff --git a/ubifs-utils/fsck.ubifs/.gitignore b/ubifs-utils/fsck.ubifs/.gitignore
new file mode 100644
index 00000000..09d664aa
--- /dev/null
+++ b/ubifs-utils/fsck.ubifs/.gitignore
@@ -0,0 +1 @@
+/fsck.ubifs
diff --git a/ubifs-utils/fsck.ubifs/fsck.ubifs.c b/ubifs-utils/fsck.ubifs/fsck.ubifs.c
new file mode 100644
index 00000000..b1286150
--- /dev/null
+++ b/ubifs-utils/fsck.ubifs/fsck.ubifs.c
@@ -0,0 +1,259 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024, Huawei Technologies Co, Ltd.
+ *
+ * Authors: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <signal.h>
+
+#include "bitops.h"
+#include "kmem.h"
+#include "ubifs.h"
+#include "defs.h"
+#include "debug.h"
+#include "key.h"
+#include "misc.h"
+#include "fsck.ubifs.h"
+
+/*
+ * Because we copy functions from the kernel, we use a subset of the UBIFS
+ * file-system description object struct ubifs_info.
+ */
+struct ubifs_info info_;
+static struct ubifs_info *c = &info_;
+
+int exit_code = FSCK_OK;
+
+static const char *optstring = "Vrg:abyn";
+
+static const struct option longopts[] = {
+ {"version", 0, NULL, 'V'},
+ {"reserve", 1, NULL, 'r'},
+ {"debug", 1, NULL, 'g'},
+ {"auto", 1, NULL, 'a'},
+ {"rebuild", 1, NULL, 'b'},
+ {"yes", 1, NULL, 'y'},
+ {"nochange", 1, NULL, 'n'},
+ {NULL, 0, NULL, 0}
+};
+
+static const char *helptext =
+"Usage: fsck.ubifs [OPTIONS] ubi_volume\n"
+"Check & repair UBIFS filesystem on a given UBI volume\n\n"
+"Options:\n"
+"-V, --version Display version information\n"
+"-g, --debug=LEVEL Display debug information (0 - none, 1 - error message,\n"
+" 2 - warning message[default], 3 - notice message, 4 - debug message)\n"
+"-a, --auto Automatic safely repair without droping data (No questions).\n"
+" Can not be specified at the same time as the -y or -n options\n"
+"-y, --yes Assume \"yes\" to all questions. Automatic repair and report dropping data (No questions).\n"
+" There are two submodes for this working mode:\n"
+" a. default - Fail if TNC/master/log is corrupted. Only -y option is specified\n"
+" b. rebuild fs - Turn to rebuild fs if TNC/master/log is corrupted. Specify -b option to make effect\n"
+" Can not be specified at the same time as the -a or -n options\n"
+"-b, --rebuild Forcedly repair the filesystem even by rebuilding filesystem.\n"
+" Depends on -y option\n"
+"-n, --nochange Make no changes to the filesystem, only check filesystem.\n"
+" Can not be specified at the same time as the -a or -y options\n"
+"Examples:\n"
+"\t1. Check and repair filesystem from UBI volume /dev/ubi0_0\n"
+"\t fsck.ubifs /dev/ubi0_0\n"
+"\t2. Only check without modifying filesystem from UBI volume /dev/ubi0_0\n"
+"\t fsck.ubifs -n /dev/ubi0_0\n"
+"\t3. Check and safely repair filesystem from UBI volume /dev/ubi0_0\n"
+"\t fsck.ubifs -a /dev/ubi0_0\n"
+"\t4. Check and forcedly repair filesystem from UBI volume /dev/ubi0_0\n"
+"\t fsck.ubifs -y -b /dev/ubi0_0\n\n";
+
+static inline void usage(void)
+{
+ printf("%s", helptext);
+ exit_code |= FSCK_USAGE;
+ exit(exit_code);
+}
+
+static void get_options(int argc, char* argv[], int *mode)
+{
+ int opt, i, submode = 0;
+ char *endp;
+
+ while (1) {
+ opt = getopt_long(argc, argv, optstring, longopts, &i);
+ if (opt == -1)
+ break;
+ switch (opt) {
+ case 'V':
+ common_print_version();
+ exit(FSCK_OK);
+ case 'g':
+ c->debug_level = strtol(optarg, &endp, 0);
+ if (*endp != '\0' || endp == optarg ||
+ c->debug_level < 0 || c->debug_level > DEBUG_LEVEL) {
+ log_err(c, 0, "bad debugging level '%s'", optarg);
+ usage();
+ }
+ break;
+ case 'a':
+ if (*mode != NORMAL_MODE) {
+ conflict_opt:
+ log_err(c, 0, "Only one of the options -a, -n or -y may be specified");
+ usage();
+ }
+ *mode = SAFE_MODE;
+ break;
+ case 'y':
+ if (*mode != NORMAL_MODE)
+ goto conflict_opt;
+ *mode = DANGER_MODE0;
+ break;
+ case 'b':
+ submode = 1;
+ break;
+ case 'n':
+ if (*mode != NORMAL_MODE)
+ goto conflict_opt;
+ *mode = CHECK_MODE;
+ c->ro_mount = 1;
+ break;
+ case 'r':
+ /* Compatible with FSCK(8). */
+ break;
+ default:
+ usage();
+ }
+ }
+
+ if (submode) {
+ if (*mode != DANGER_MODE0) {
+ log_err(c, 0, "Option -y is not specified when -b is used");
+ usage();
+ } else
+ *mode = DANGER_MODE1;
+ }
+
+ if (optind != argc) {
+ c->dev_name = strdup(argv[optind]);
+ if (!c->dev_name) {
+ log_err(c, errno, "can not allocate dev_name");
+ exit_code |= FSCK_ERROR;
+ exit(exit_code);
+ }
+ }
+
+ if (!c->dev_name) {
+ log_err(c, 0, "no ubi_volume specified");
+ usage();
+ }
+}
+
+static void exit_callback(void)
+{
+ if (exit_code & FSCK_NONDESTRUCT)
+ log_out(c, "********** Filesystem was modified **********");
+ if (exit_code & FSCK_UNCORRECTED)
+ log_out(c, "********** WARNING: Filesystem still has errors **********");
+ if (exit_code & ~(FSCK_OK|FSCK_NONDESTRUCT))
+ log_out(c, "FSCK failed, exit code %d", exit_code);
+ else
+ log_out(c, "FSCK success!");
+}
+
+static void fsck_assert_failed(__unused const struct ubifs_info *c)
+{
+ exit_code |= FSCK_ERROR;
+ exit(exit_code);
+}
+
+static void signal_cancel(int sig)
+{
+ ubifs_warn(c, "killed by signo %d", sig);
+ exit_code |= FSCK_CANCELED;
+ exit(exit_code);
+}
+
+static int init_fsck_info(struct ubifs_info *c, int argc, char *argv[])
+{
+ int err = 0, mode = NORMAL_MODE;
+ struct sigaction sa;
+ struct ubifs_fsck_info *fsck = NULL;
+
+ if (atexit(exit_callback)) {
+ log_err(c, errno, "can not set exit callback");
+ return -errno;
+ }
+
+ init_ubifs_info(c, FSCK_PROGRAM_TYPE);
+ get_options(argc, argv, &mode);
+
+ fsck = calloc(1, sizeof(struct ubifs_fsck_info));
+ if (!fsck) {
+ err = -errno;
+ log_err(c, errno, "can not allocate fsck info");
+ goto out_err;
+ }
+
+ c->private = fsck;
+ FSCK(c)->mode = mode;
+ c->assert_failed_cb = fsck_assert_failed;
+
+ memset(&sa, 0, sizeof(struct sigaction));
+ sa.sa_handler = signal_cancel;
+ if (sigaction(SIGINT, &sa, NULL) || sigaction(SIGTERM, &sa, NULL)) {
+ err = -errno;
+ log_err(c, errno, "can not set signal handler");
+ goto out_err;
+ }
+
+ return 0;
+
+out_err:
+ free(fsck);
+ free(c->dev_name);
+ c->dev_name = NULL;
+ return err;
+}
+
+static void destroy_fsck_info(struct ubifs_info *c)
+{
+ free(c->private);
+ c->private = NULL;
+ free(c->dev_name);
+ c->dev_name = NULL;
+}
+
+/*
+ * do_fsck - Check & repair the filesystem.
+ */
+static int do_fsck(void)
+{
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ int err;
+
+ err = init_fsck_info(c, argc, argv);
+ if (err) {
+ exit_code |= FSCK_ERROR;
+ goto out_exit;
+ }
+
+ err = ubifs_open_volume(c, c->dev_name);
+ if (err) {
+ exit_code |= FSCK_ERROR;
+ goto out_destroy_fsck;
+ }
+
+ err = do_fsck();
+
+ ubifs_close_volume(c);
+out_destroy_fsck:
+ destroy_fsck_info(c);
+out_exit:
+ return exit_code;
+}
diff --git a/ubifs-utils/fsck.ubifs/fsck.ubifs.h b/ubifs-utils/fsck.ubifs/fsck.ubifs.h
new file mode 100644
index 00000000..d267dd24
--- /dev/null
+++ b/ubifs-utils/fsck.ubifs/fsck.ubifs.h
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024, Huawei Technologies Co, Ltd.
+ *
+ * Authors: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
+ */
+
+#ifndef __FSCK_UBIFS_H__
+#define __FSCK_UBIFS_H__
+
+/* Exit codes used by fsck-type programs */
+#define FSCK_OK 0 /* No errors */
+#define FSCK_NONDESTRUCT 1 /* File system errors corrected */
+#define FSCK_REBOOT 2 /* System should be rebooted */
+#define FSCK_UNCORRECTED 4 /* File system errors left uncorrected */
+#define FSCK_ERROR 8 /* Operational error */
+#define FSCK_USAGE 16 /* Usage or syntax error */
+#define FSCK_CANCELED 32 /* Aborted with a signal or ^C */
+#define FSCK_LIBRARY 128 /* Shared library error */
+
+/*
+ * There are 6 working modes for fsck:
+ * NORMAL_MODE: Check the filesystem, ask user whether or not to fix the
+ * problem as long as inconsistent data is found during checking.
+ * SAFE_MODE: Check and safely repair the filesystem, if there are any
+ * data dropping operations needed by fixing, fsck will fail.
+ * DANGER_MODE0:Check and repair the filesystem according to TNC, data dropping
+ * will be reported. If TNC/master/log is corrupted, fsck will fail.
+ * DANGER_MODE1:Check and forcedly repair the filesystem according to TNC,
+ * turns to @REBUILD_MODE mode automatically if TNC/master/log is
+ * corrupted.
+ * REBUILD_MODE:Scan entire UBI volume to find all nodes, and rebuild the
+ * filesystem, always make fsck success.
+ * CHECK_MODE: Make no changes to the filesystem, only check the filesystem.
+ */
+enum { NORMAL_MODE = 0, SAFE_MODE, DANGER_MODE0,
+ DANGER_MODE1, REBUILD_MODE, CHECK_MODE };
+
+/**
+ * struct ubifs_fsck_info - UBIFS fsck information.
+ * @mode: working mode
+ */
+struct ubifs_fsck_info {
+ int mode;
+};
+
+#define FSCK(c) ((struct ubifs_fsck_info*)c->private)
+
+static inline const char *mode_name(const struct ubifs_info *c)
+{
+ if (!c->private)
+ return "";
+
+ switch (FSCK(c)->mode) {
+ case NORMAL_MODE:
+ return ",normal mode";
+ case SAFE_MODE:
+ return ",safe mode";
+ case DANGER_MODE0:
+ return ",danger mode";
+ case DANGER_MODE1:
+ return ",danger + rebuild mode";
+ case REBUILD_MODE:
+ return ",rebuild mode";
+ case CHECK_MODE:
+ return ",check mode";
+ default:
+ return "";
+ }
+}
+
+#define log_out(c, fmt, ...) do { \
+ printf("%s[%d] (%s%s): " fmt "\n", c->program_name ? : "noprog",\
+ getpid(), c->dev_name ? : "-", mode_name(c), \
+ ##__VA_ARGS__); \
+} while (0)
+
+#define log_err(c, err, fmt, ...) do { \
+ printf("%s[%d][ERROR] (%s%s): %s: " fmt, \
+ c->program_name ? : "noprog", getpid(), \
+ c->dev_name ? : "-", mode_name(c), \
+ __FUNCTION__, ##__VA_ARGS__); \
+ if (err) \
+ printf(" - %s", strerror(err)); \
+ printf("\n"); \
+} while (0)
+
+/* Exit code for fsck program. */
+extern int exit_code;
+
+#endif
diff --git a/ubifs-utils/libubifs/debug.c b/ubifs-utils/libubifs/debug.c
index a2109906..94928da3 100644
--- a/ubifs-utils/libubifs/debug.c
+++ b/ubifs-utils/libubifs/debug.c
@@ -1021,7 +1021,11 @@ void ubifs_assert_failed(struct ubifs_info *c, const char *expr,

/*
* Different from linux kernel.
- * There is only one action(readonly) when assertion is failed.
+ * Invoke callback function if there is one, otherwise make filesystem
+ * readonly when assertion is failed.
*/
- ubifs_ro_mode(c, -EINVAL);
+ if (c->assert_failed_cb)
+ c->assert_failed_cb(c);
+ else
+ ubifs_ro_mode(c, -EINVAL);
}
diff --git a/ubifs-utils/libubifs/super.c b/ubifs-utils/libubifs/super.c
index 9fa366f3..155489d9 100644
--- a/ubifs-utils/libubifs/super.c
+++ b/ubifs-utils/libubifs/super.c
@@ -138,6 +138,53 @@ int close_target(struct ubifs_info *c)
}

/**
+ * ubifs_open_volume - open UBI volume.
+ * @c: the UBIFS file-system description object
+ * @volume_name: the UBI volume name
+ *
+ * Open ubi volume. This function is implemented by open_ubi + open_target.
+ *
+ * Returns %0 in case of success and a negative error code in case of failure.
+ */
+int ubifs_open_volume(struct ubifs_info *c, const char *volume_name)
+{
+ int err;
+
+ err = open_ubi(c, volume_name);
+ if (err) {
+ ubifs_err(c, "cannot open libubi. %s", strerror(errno));
+ return err;
+ }
+
+ err = open_target(c);
+ if (err)
+ close_ubi(c);
+
+ return err;
+}
+
+/**
+ * ubifs_close_volume - close UBI volume.
+ * @c: the UBIFS file-system description object
+ *
+ * Close ubi volume. This function is implemented by close_target + close_ubi.
+ *
+ * Returns %0 in case of success and a negative error code in case of failure.
+ */
+int ubifs_close_volume(struct ubifs_info *c)
+{
+ int err;
+
+ err = close_target(c);
+ if (err)
+ return err;
+
+ close_ubi(c);
+
+ return 0;
+}
+
+/**
* check_volume_empty - check if the UBI volume is empty.
* @c: the UBIFS file-system description object
*
@@ -197,6 +244,11 @@ void init_ubifs_info(struct ubifs_info *c, int program_type)
case MKFS_PROGRAM_TYPE:
c->program_name = MKFS_PROGRAM_NAME;
break;
+ case FSCK_PROGRAM_TYPE:
+ c->program_name = FSCK_PROGRAM_NAME;
+ /* Always check crc for data node. */
+ c->no_chk_data_crc = 0;
+ break;
default:
assert(0);
break;
diff --git a/ubifs-utils/libubifs/ubifs.h b/ubifs-utils/libubifs/ubifs.h
index 2af9d87b..babaae8f 100644
--- a/ubifs-utils/libubifs/ubifs.h
+++ b/ubifs-utils/libubifs/ubifs.h
@@ -1026,6 +1026,9 @@ struct ubifs_budg_info {
*
* @new_ihead_lnum: used by debugging to check @c->ihead_lnum
* @new_ihead_offs: used by debugging to check @c->ihead_offs
+ *
+ * @private: private information related to specific situation, eg. fsck.
+ * @assert_failed_cb: callback function to handle assertion failure
*/
struct ubifs_info {
struct ubifs_sb_node *sup_node;
@@ -1248,6 +1251,9 @@ struct ubifs_info {

int new_ihead_lnum;
int new_ihead_offs;
+
+ void *private;
+ void (*assert_failed_cb)(const struct ubifs_info *c);
};

extern atomic_long_t ubifs_clean_zn_cnt;
@@ -1684,6 +1690,8 @@ int open_ubi(struct ubifs_info *c, const char *node);
void close_ubi(struct ubifs_info *c);
int open_target(struct ubifs_info *c);
int close_target(struct ubifs_info *c);
+int ubifs_open_volume(struct ubifs_info *c, const char *volume_name);
+int ubifs_close_volume(struct ubifs_info *c);
int check_volume_empty(struct ubifs_info *c);
void init_ubifs_info(struct ubifs_info *c, int program_type);
int init_constants_early(struct ubifs_info *c);
--
2.13.6