drivers/mtd/ubi/debug.c - kernel/mindspeed - Git at Google

 /*
  * Copyright (c) International Business Machines Corp., 2006
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  * the GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  *
  * Author: Artem Bityutskiy (Битюцкий Артём)
  */

 /*
  * Here we keep all the UBI debugging stuff which should normally be disabled
  * and compiled-out, but it is extremely helpful when hunting bugs or doing big
  * changes.
  */

 #ifdef CONFIG_MTD_UBI_DEBUG

 #include "ubi.h"
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/module.h>

 /**
  * ubi_dbg_dump_ec_hdr - dump an erase counter header.
  * @ec_hdr: the erase counter header to dump
  */
 void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr)
 {
 	printk(KERN_DEBUG "Erase counter header dump:\n");
 	printk(KERN_DEBUG "\tmagic          %#08x\n",
 	       be32_to_cpu(ec_hdr->magic));
 	printk(KERN_DEBUG "\tversion        %d\n", (int)ec_hdr->version);
 	printk(KERN_DEBUG "\tec             %llu\n",
 	       (long long)be64_to_cpu(ec_hdr->ec));
 	printk(KERN_DEBUG "\tvid_hdr_offset %d\n",
 	       be32_to_cpu(ec_hdr->vid_hdr_offset));
 	printk(KERN_DEBUG "\tdata_offset    %d\n",
 	       be32_to_cpu(ec_hdr->data_offset));
 	printk(KERN_DEBUG "\timage_seq      %d\n",
 	       be32_to_cpu(ec_hdr->image_seq));
 	printk(KERN_DEBUG "\thdr_crc        %#08x\n",
 	       be32_to_cpu(ec_hdr->hdr_crc));
 	printk(KERN_DEBUG "erase counter header hexdump:\n");
 	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
 		       ec_hdr, UBI_EC_HDR_SIZE, 1);
 }

 /**
  * ubi_dbg_dump_vid_hdr - dump a volume identifier header.
  * @vid_hdr: the volume identifier header to dump
  */
 void ubi_dbg_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr)
 {
 	printk(KERN_DEBUG "Volume identifier header dump:\n");
 	printk(KERN_DEBUG "\tmagic     %08x\n", be32_to_cpu(vid_hdr->magic));
 	printk(KERN_DEBUG "\tversion   %d\n",  (int)vid_hdr->version);
 	printk(KERN_DEBUG "\tvol_type  %d\n",  (int)vid_hdr->vol_type);
 	printk(KERN_DEBUG "\tcopy_flag %d\n",  (int)vid_hdr->copy_flag);
 	printk(KERN_DEBUG "\tcompat    %d\n",  (int)vid_hdr->compat);
 	printk(KERN_DEBUG "\tvol_id    %d\n",  be32_to_cpu(vid_hdr->vol_id));
 	printk(KERN_DEBUG "\tlnum      %d\n",  be32_to_cpu(vid_hdr->lnum));
 	printk(KERN_DEBUG "\tdata_size %d\n",  be32_to_cpu(vid_hdr->data_size));
 	printk(KERN_DEBUG "\tused_ebs  %d\n",  be32_to_cpu(vid_hdr->used_ebs));
 	printk(KERN_DEBUG "\tdata_pad  %d\n",  be32_to_cpu(vid_hdr->data_pad));
 	printk(KERN_DEBUG "\tsqnum     %llu\n",
 		(unsigned long long)be64_to_cpu(vid_hdr->sqnum));
 	printk(KERN_DEBUG "\thdr_crc   %08x\n", be32_to_cpu(vid_hdr->hdr_crc));
 	printk(KERN_DEBUG "Volume identifier header hexdump:\n");
 	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
 		       vid_hdr, UBI_VID_HDR_SIZE, 1);
 }

 /**
  * ubi_dbg_dump_vol_info- dump volume information.
  * @vol: UBI volume description object
  */
 void ubi_dbg_dump_vol_info(const struct ubi_volume *vol)
 {
 	printk(KERN_DEBUG "Volume information dump:\n");
 	printk(KERN_DEBUG "\tvol_id          %d\n", vol->vol_id);
 	printk(KERN_DEBUG "\treserved_pebs   %d\n", vol->reserved_pebs);
 	printk(KERN_DEBUG "\talignment       %d\n", vol->alignment);
 	printk(KERN_DEBUG "\tdata_pad        %d\n", vol->data_pad);
 	printk(KERN_DEBUG "\tvol_type        %d\n", vol->vol_type);
 	printk(KERN_DEBUG "\tname_len        %d\n", vol->name_len);
 	printk(KERN_DEBUG "\tusable_leb_size %d\n", vol->usable_leb_size);
 	printk(KERN_DEBUG "\tused_ebs        %d\n", vol->used_ebs);
 	printk(KERN_DEBUG "\tused_bytes      %lld\n", vol->used_bytes);
 	printk(KERN_DEBUG "\tlast_eb_bytes   %d\n", vol->last_eb_bytes);
 	printk(KERN_DEBUG "\tcorrupted       %d\n", vol->corrupted);
 	printk(KERN_DEBUG "\tupd_marker      %d\n", vol->upd_marker);

 	if (vol->name_len <= UBI_VOL_NAME_MAX &&
 	    strnlen(vol->name, vol->name_len + 1) == vol->name_len) {
 		printk(KERN_DEBUG "\tname            %s\n", vol->name);
 	} else {
 		printk(KERN_DEBUG "\t1st 5 characters of name: %c%c%c%c%c\n",
 		       vol->name[0], vol->name[1], vol->name[2],
 		       vol->name[3], vol->name[4]);
 	}
 }

 /**
  * ubi_dbg_dump_vtbl_record - dump a &struct ubi_vtbl_record object.
  * @r: the object to dump
  * @idx: volume table index
  */
 void ubi_dbg_dump_vtbl_record(const struct ubi_vtbl_record *r, int idx)
 {
 	int name_len = be16_to_cpu(r->name_len);

 	printk(KERN_DEBUG "Volume table record %d dump:\n", idx);
 	printk(KERN_DEBUG "\treserved_pebs   %d\n",
 	       be32_to_cpu(r->reserved_pebs));
 	printk(KERN_DEBUG "\talignment       %d\n", be32_to_cpu(r->alignment));
 	printk(KERN_DEBUG "\tdata_pad        %d\n", be32_to_cpu(r->data_pad));
 	printk(KERN_DEBUG "\tvol_type        %d\n", (int)r->vol_type);
 	printk(KERN_DEBUG "\tupd_marker      %d\n", (int)r->upd_marker);
 	printk(KERN_DEBUG "\tname_len        %d\n", name_len);

 	if (r->name[0] == '\0') {
 		printk(KERN_DEBUG "\tname            NULL\n");
 		return;
 	}

 	if (name_len <= UBI_VOL_NAME_MAX &&
 	    strnlen(&r->name[0], name_len + 1) == name_len) {
 		printk(KERN_DEBUG "\tname            %s\n", &r->name[0]);
 	} else {
 		printk(KERN_DEBUG "\t1st 5 characters of name: %c%c%c%c%c\n",
 			r->name[0], r->name[1], r->name[2], r->name[3],
 			r->name[4]);
 	}
 	printk(KERN_DEBUG "\tcrc             %#08x\n", be32_to_cpu(r->crc));
 }

 /**
  * ubi_dbg_dump_sv - dump a &struct ubi_scan_volume object.
  * @sv: the object to dump
  */
 void ubi_dbg_dump_sv(const struct ubi_scan_volume *sv)
 {
 	printk(KERN_DEBUG "Volume scanning information dump:\n");
 	printk(KERN_DEBUG "\tvol_id         %d\n", sv->vol_id);
 	printk(KERN_DEBUG "\thighest_lnum   %d\n", sv->highest_lnum);
 	printk(KERN_DEBUG "\tleb_count      %d\n", sv->leb_count);
 	printk(KERN_DEBUG "\tcompat         %d\n", sv->compat);
 	printk(KERN_DEBUG "\tvol_type       %d\n", sv->vol_type);
 	printk(KERN_DEBUG "\tused_ebs       %d\n", sv->used_ebs);
 	printk(KERN_DEBUG "\tlast_data_size %d\n", sv->last_data_size);
 	printk(KERN_DEBUG "\tdata_pad       %d\n", sv->data_pad);
 }

 /**
  * ubi_dbg_dump_seb - dump a &struct ubi_scan_leb object.
  * @seb: the object to dump
  * @type: object type: 0 - not corrupted, 1 - corrupted
  */
 void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type)
 {
 	printk(KERN_DEBUG "eraseblock scanning information dump:\n");
 	printk(KERN_DEBUG "\tec       %d\n", seb->ec);
 	printk(KERN_DEBUG "\tpnum     %d\n", seb->pnum);
 	if (type == 0) {
 		printk(KERN_DEBUG "\tlnum     %d\n", seb->lnum);
 		printk(KERN_DEBUG "\tscrub    %d\n", seb->scrub);
 		printk(KERN_DEBUG "\tsqnum    %llu\n", seb->sqnum);
 	}
 }

 /**
  * ubi_dbg_dump_mkvol_req - dump a &struct ubi_mkvol_req object.
  * @req: the object to dump
  */
 void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req)
 {
 	char nm[17];

 	printk(KERN_DEBUG "Volume creation request dump:\n");
 	printk(KERN_DEBUG "\tvol_id    %d\n",   req->vol_id);
 	printk(KERN_DEBUG "\talignment %d\n",   req->alignment);
 	printk(KERN_DEBUG "\tbytes     %lld\n", (long long)req->bytes);
 	printk(KERN_DEBUG "\tvol_type  %d\n",   req->vol_type);
 	printk(KERN_DEBUG "\tname_len  %d\n",   req->name_len);

 	memcpy(nm, req->name, 16);
 	nm[16] = 0;
 	printk(KERN_DEBUG "\t1st 16 characters of name: %s\n", nm);
 }

 /**
  * ubi_dbg_dump_flash - dump a region of flash.
  * @ubi: UBI device description object
  * @pnum: the physical eraseblock number to dump
  * @offset: the starting offset within the physical eraseblock to dump
  * @len: the length of the region to dump
  */
 void ubi_dbg_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len)
 {
 	int err;
 	size_t read;
 	void *buf;
 	loff_t addr = (loff_t)pnum * ubi->peb_size + offset;

 	buf = vmalloc(len);
 	if (!buf)
 		return;
 	err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
 	if (err && err != -EUCLEAN) {
 		ubi_err("error %d while reading %d bytes from PEB %d:%d, "
 			"read %zd bytes", err, len, pnum, offset, read);
 		goto out;
 	}

 	dbg_msg("dumping %d bytes of data from PEB %d, offset %d",
 		len, pnum, offset);
 	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
 out:
 	vfree(buf);
 	return;
 }

 /**
  * ubi_debugging_init_dev - initialize debugging for an UBI device.
  * @ubi: UBI device description object
  *
  * This function initializes debugging-related data for UBI device @ubi.
  * Returns zero in case of success and a negative error code in case of
  * failure.
  */
 int ubi_debugging_init_dev(struct ubi_device *ubi)
 {
 	ubi->dbg = kzalloc(sizeof(struct ubi_debug_info), GFP_KERNEL);
 	if (!ubi->dbg)
 		return -ENOMEM;

 	return 0;
 }

 /**
  * ubi_debugging_exit_dev - free debugging data for an UBI device.
  * @ubi: UBI device description object
  */
 void ubi_debugging_exit_dev(struct ubi_device *ubi)
 {
 	kfree(ubi->dbg);
 }

 /*
  * Root directory for UBI stuff in debugfs. Contains sub-directories which
  * contain the stuff specific to particular UBI devices.
  */
 static struct dentry *dfs_rootdir;

 /**
  * ubi_debugfs_init - create UBI debugfs directory.
  *
  * Create UBI debugfs directory. Returns zero in case of success and a negative
  * error code in case of failure.
  */
 int ubi_debugfs_init(void)
 {
 	dfs_rootdir = debugfs_create_dir("ubi", NULL);
 	if (IS_ERR_OR_NULL(dfs_rootdir)) {
 		int err = dfs_rootdir ? -ENODEV : PTR_ERR(dfs_rootdir);

 		ubi_err("cannot create \"ubi\" debugfs directory, error %d\n",
 			err);
 		return err;
 	}

 	return 0;
 }

 /**
  * ubi_debugfs_exit - remove UBI debugfs directory.
  */
 void ubi_debugfs_exit(void)
 {
 	debugfs_remove(dfs_rootdir);
 }

 /* Read an UBI debugfs file */
 static ssize_t dfs_file_read(struct file *file, char __user *user_buf,
 			     size_t count, loff_t *ppos)
 {
 	unsigned long ubi_num = (unsigned long)file->private_data;
 	struct dentry *dent = file->f_path.dentry;
 	struct ubi_device *ubi;
 	struct ubi_debug_info *d;
 	char buf[3];
 	int val;

 	ubi = ubi_get_device(ubi_num);
 	if (!ubi)
 		return -ENODEV;
 	d = ubi->dbg;

 	if (dent == d->dfs_chk_gen)
 		val = d->chk_gen;
 	else if (dent == d->dfs_chk_io)
 		val = d->chk_io;
 	else if (dent == d->dfs_disable_bgt)
 		val = d->disable_bgt;
 	else if (dent == d->dfs_emulate_bitflips)
 		val = d->emulate_bitflips;
 	else if (dent == d->dfs_emulate_io_failures)
 		val = d->emulate_io_failures;
 	else {
 		count = -EINVAL;
 		goto out;
 	}

 	if (val)
 		buf[0] = '1';
 	else
 		buf[0] = '0';
 	buf[1] = '\n';
 	buf[2] = 0x00;

 	count = simple_read_from_buffer(user_buf, count, ppos, buf, 2);

 out:
 	ubi_put_device(ubi);
 	return count;
 }

 /* Write an UBI debugfs file */
 static ssize_t dfs_file_write(struct file *file, const char __user *user_buf,
 			      size_t count, loff_t *ppos)
 {
 	unsigned long ubi_num = (unsigned long)file->private_data;
 	struct dentry *dent = file->f_path.dentry;
 	struct ubi_device *ubi;
 	struct ubi_debug_info *d;
 	size_t buf_size;
 	char buf[8];
 	int val;

 	ubi = ubi_get_device(ubi_num);
 	if (!ubi)
 		return -ENODEV;
 	d = ubi->dbg;

 	buf_size = min_t(size_t, count, (sizeof(buf) - 1));
 	if (copy_from_user(buf, user_buf, buf_size)) {
 		count = -EFAULT;
 		goto out;
 	}

 	if (buf[0] == '1')
 		val = 1;
 	else if (buf[0] == '0')
 		val = 0;
 	else {
 		count = -EINVAL;
 		goto out;
 	}

 	if (dent == d->dfs_chk_gen)
 		d->chk_gen = val;
 	else if (dent == d->dfs_chk_io)
 		d->chk_io = val;
 	else if (dent == d->dfs_disable_bgt)
 		d->disable_bgt = val;
 	else if (dent == d->dfs_emulate_bitflips)
 		d->emulate_bitflips = val;
 	else if (dent == d->dfs_emulate_io_failures)
 		d->emulate_io_failures = val;
 	else
 		count = -EINVAL;

 out:
 	ubi_put_device(ubi);
 	return count;
 }

 static int default_open(struct inode *inode, struct file *file)
 {
 	if (inode->i_private)
 		file->private_data = inode->i_private;

 	return 0;
 }

 /* File operations for all UBI debugfs files */
 static const struct file_operations dfs_fops = {
 	.read   = dfs_file_read,
 	.write  = dfs_file_write,
 	.open   = default_open,
 	.llseek = no_llseek,
 	.owner  = THIS_MODULE,
 };

 /**
  * ubi_debugfs_init_dev - initialize debugfs for an UBI device.
  * @ubi: UBI device description object
  *
  * This function creates all debugfs files for UBI device @ubi. Returns zero in
  * case of success and a negative error code in case of failure.
  */
 int ubi_debugfs_init_dev(struct ubi_device *ubi)
 {
 	int err, n;
 	unsigned long ubi_num = ubi->ubi_num;
 	const char *fname;
 	struct dentry *dent;
 	struct ubi_debug_info *d = ubi->dbg;

 	n = snprintf(d->dfs_dir_name, UBI_DFS_DIR_LEN + 1, UBI_DFS_DIR_NAME,
 		     ubi->ubi_num);
 	if (n == UBI_DFS_DIR_LEN) {
 		/* The array size is too small */
 		fname = UBI_DFS_DIR_NAME;
 		dent = ERR_PTR(-EINVAL);
 		goto out;
 	}

 	fname = d->dfs_dir_name;
 	dent = debugfs_create_dir(fname, dfs_rootdir);
 	if (IS_ERR_OR_NULL(dent))
 		goto out;
 	d->dfs_dir = dent;

 	fname = "chk_gen";
 	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
 				   &dfs_fops);
 	if (IS_ERR_OR_NULL(dent))
 		goto out_remove;
 	d->dfs_chk_gen = dent;

 	fname = "chk_io";
 	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
 				   &dfs_fops);
 	if (IS_ERR_OR_NULL(dent))
 		goto out_remove;
 	d->dfs_chk_io = dent;

 	fname = "tst_disable_bgt";
 	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
 				   &dfs_fops);
 	if (IS_ERR_OR_NULL(dent))
 		goto out_remove;
 	d->dfs_disable_bgt = dent;

 	fname = "tst_emulate_bitflips";
 	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
 				   &dfs_fops);
 	if (IS_ERR_OR_NULL(dent))
 		goto out_remove;
 	d->dfs_emulate_bitflips = dent;

 	fname = "tst_emulate_io_failures";
 	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
 				   &dfs_fops);
 	if (IS_ERR_OR_NULL(dent))
 		goto out_remove;
 	d->dfs_emulate_io_failures = dent;

 	return 0;

 out_remove:
 	debugfs_remove_recursive(d->dfs_dir);
 out:
 	err = dent ? PTR_ERR(dent) : -ENODEV;
 	ubi_err("cannot create \"%s\" debugfs file or directory, error %d\n",
 		fname, err);
 	return err;
 }

 /**
  * dbg_debug_exit_dev - free all debugfs files corresponding to device @ubi
  * @ubi: UBI device description object
  */
 void ubi_debugfs_exit_dev(struct ubi_device *ubi)
 {
 	debugfs_remove_recursive(ubi->dbg->dfs_dir);
 }

 #endif /* CONFIG_MTD_UBI_DEBUG */
	/*
	* Copyright (c) International Business Machines Corp., 2006
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
	* the GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	* Author: Artem Bityutskiy (Битюцкий Артём)
	*/

	/*
	* Here we keep all the UBI debugging stuff which should normally be disabled
	* and compiled-out, but it is extremely helpful when hunting bugs or doing big
	* changes.
	*/

	#ifdef CONFIG_MTD_UBI_DEBUG

	#include "ubi.h"
	#include <linux/debugfs.h>
	#include <linux/uaccess.h>
	#include <linux/module.h>

	/**
	* ubi_dbg_dump_ec_hdr - dump an erase counter header.
	* @ec_hdr: the erase counter header to dump
	*/
	void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr)
	{
	printk(KERN_DEBUG "Erase counter header dump:\n");
	printk(KERN_DEBUG "\tmagic %#08x\n",
	be32_to_cpu(ec_hdr->magic));
	printk(KERN_DEBUG "\tversion %d\n", (int)ec_hdr->version);
	printk(KERN_DEBUG "\tec %llu\n",
	(long long)be64_to_cpu(ec_hdr->ec));
	printk(KERN_DEBUG "\tvid_hdr_offset %d\n",
	be32_to_cpu(ec_hdr->vid_hdr_offset));
	printk(KERN_DEBUG "\tdata_offset %d\n",
	be32_to_cpu(ec_hdr->data_offset));
	printk(KERN_DEBUG "\timage_seq %d\n",
	be32_to_cpu(ec_hdr->image_seq));
	printk(KERN_DEBUG "\thdr_crc %#08x\n",
	be32_to_cpu(ec_hdr->hdr_crc));
	printk(KERN_DEBUG "erase counter header hexdump:\n");
	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
	ec_hdr, UBI_EC_HDR_SIZE, 1);
	}

	/**
	* ubi_dbg_dump_vid_hdr - dump a volume identifier header.
	* @vid_hdr: the volume identifier header to dump
	*/
	void ubi_dbg_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr)
	{
	printk(KERN_DEBUG "Volume identifier header dump:\n");
	printk(KERN_DEBUG "\tmagic %08x\n", be32_to_cpu(vid_hdr->magic));
	printk(KERN_DEBUG "\tversion %d\n", (int)vid_hdr->version);
	printk(KERN_DEBUG "\tvol_type %d\n", (int)vid_hdr->vol_type);
	printk(KERN_DEBUG "\tcopy_flag %d\n", (int)vid_hdr->copy_flag);
	printk(KERN_DEBUG "\tcompat %d\n", (int)vid_hdr->compat);
	printk(KERN_DEBUG "\tvol_id %d\n", be32_to_cpu(vid_hdr->vol_id));
	printk(KERN_DEBUG "\tlnum %d\n", be32_to_cpu(vid_hdr->lnum));
	printk(KERN_DEBUG "\tdata_size %d\n", be32_to_cpu(vid_hdr->data_size));
	printk(KERN_DEBUG "\tused_ebs %d\n", be32_to_cpu(vid_hdr->used_ebs));
	printk(KERN_DEBUG "\tdata_pad %d\n", be32_to_cpu(vid_hdr->data_pad));
	printk(KERN_DEBUG "\tsqnum %llu\n",
	(unsigned long long)be64_to_cpu(vid_hdr->sqnum));
	printk(KERN_DEBUG "\thdr_crc %08x\n", be32_to_cpu(vid_hdr->hdr_crc));
	printk(KERN_DEBUG "Volume identifier header hexdump:\n");
	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
	vid_hdr, UBI_VID_HDR_SIZE, 1);
	}

	/**
	* ubi_dbg_dump_vol_info- dump volume information.
	* @vol: UBI volume description object
	*/
	void ubi_dbg_dump_vol_info(const struct ubi_volume *vol)
	{
	printk(KERN_DEBUG "Volume information dump:\n");
	printk(KERN_DEBUG "\tvol_id %d\n", vol->vol_id);
	printk(KERN_DEBUG "\treserved_pebs %d\n", vol->reserved_pebs);
	printk(KERN_DEBUG "\talignment %d\n", vol->alignment);
	printk(KERN_DEBUG "\tdata_pad %d\n", vol->data_pad);
	printk(KERN_DEBUG "\tvol_type %d\n", vol->vol_type);
	printk(KERN_DEBUG "\tname_len %d\n", vol->name_len);
	printk(KERN_DEBUG "\tusable_leb_size %d\n", vol->usable_leb_size);
	printk(KERN_DEBUG "\tused_ebs %d\n", vol->used_ebs);
	printk(KERN_DEBUG "\tused_bytes %lld\n", vol->used_bytes);
	printk(KERN_DEBUG "\tlast_eb_bytes %d\n", vol->last_eb_bytes);
	printk(KERN_DEBUG "\tcorrupted %d\n", vol->corrupted);
	printk(KERN_DEBUG "\tupd_marker %d\n", vol->upd_marker);

	if (vol->name_len <= UBI_VOL_NAME_MAX &&
	strnlen(vol->name, vol->name_len + 1) == vol->name_len) {
	printk(KERN_DEBUG "\tname %s\n", vol->name);
	} else {
	printk(KERN_DEBUG "\t1st 5 characters of name: %c%c%c%c%c\n",
	vol->name[0], vol->name[1], vol->name[2],
	vol->name[3], vol->name[4]);
	}
	}

	/**
	* ubi_dbg_dump_vtbl_record - dump a &struct ubi_vtbl_record object.
	* @r: the object to dump
	* @idx: volume table index
	*/
	void ubi_dbg_dump_vtbl_record(const struct ubi_vtbl_record *r, int idx)
	{
	int name_len = be16_to_cpu(r->name_len);

	printk(KERN_DEBUG "Volume table record %d dump:\n", idx);
	printk(KERN_DEBUG "\treserved_pebs %d\n",
	be32_to_cpu(r->reserved_pebs));
	printk(KERN_DEBUG "\talignment %d\n", be32_to_cpu(r->alignment));
	printk(KERN_DEBUG "\tdata_pad %d\n", be32_to_cpu(r->data_pad));
	printk(KERN_DEBUG "\tvol_type %d\n", (int)r->vol_type);
	printk(KERN_DEBUG "\tupd_marker %d\n", (int)r->upd_marker);
	printk(KERN_DEBUG "\tname_len %d\n", name_len);

	if (r->name[0] == '\0') {
	printk(KERN_DEBUG "\tname NULL\n");
	return;
	}

	if (name_len <= UBI_VOL_NAME_MAX &&
	strnlen(&r->name[0], name_len + 1) == name_len) {
	printk(KERN_DEBUG "\tname %s\n", &r->name[0]);
	} else {
	printk(KERN_DEBUG "\t1st 5 characters of name: %c%c%c%c%c\n",
	r->name[0], r->name[1], r->name[2], r->name[3],
	r->name[4]);
	}
	printk(KERN_DEBUG "\tcrc %#08x\n", be32_to_cpu(r->crc));
	}

	/**
	* ubi_dbg_dump_sv - dump a &struct ubi_scan_volume object.
	* @sv: the object to dump
	*/
	void ubi_dbg_dump_sv(const struct ubi_scan_volume *sv)
	{
	printk(KERN_DEBUG "Volume scanning information dump:\n");
	printk(KERN_DEBUG "\tvol_id %d\n", sv->vol_id);
	printk(KERN_DEBUG "\thighest_lnum %d\n", sv->highest_lnum);
	printk(KERN_DEBUG "\tleb_count %d\n", sv->leb_count);
	printk(KERN_DEBUG "\tcompat %d\n", sv->compat);
	printk(KERN_DEBUG "\tvol_type %d\n", sv->vol_type);
	printk(KERN_DEBUG "\tused_ebs %d\n", sv->used_ebs);
	printk(KERN_DEBUG "\tlast_data_size %d\n", sv->last_data_size);
	printk(KERN_DEBUG "\tdata_pad %d\n", sv->data_pad);
	}

	/**
	* ubi_dbg_dump_seb - dump a &struct ubi_scan_leb object.
	* @seb: the object to dump
	* @type: object type: 0 - not corrupted, 1 - corrupted
	*/
	void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type)
	{
	printk(KERN_DEBUG "eraseblock scanning information dump:\n");
	printk(KERN_DEBUG "\tec %d\n", seb->ec);
	printk(KERN_DEBUG "\tpnum %d\n", seb->pnum);
	if (type == 0) {
	printk(KERN_DEBUG "\tlnum %d\n", seb->lnum);
	printk(KERN_DEBUG "\tscrub %d\n", seb->scrub);
	printk(KERN_DEBUG "\tsqnum %llu\n", seb->sqnum);
	}
	}

	/**
	* ubi_dbg_dump_mkvol_req - dump a &struct ubi_mkvol_req object.
	* @req: the object to dump
	*/
	void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req)
	{
	char nm[17];

	printk(KERN_DEBUG "Volume creation request dump:\n");
	printk(KERN_DEBUG "\tvol_id %d\n", req->vol_id);
	printk(KERN_DEBUG "\talignment %d\n", req->alignment);
	printk(KERN_DEBUG "\tbytes %lld\n", (long long)req->bytes);
	printk(KERN_DEBUG "\tvol_type %d\n", req->vol_type);
	printk(KERN_DEBUG "\tname_len %d\n", req->name_len);

	memcpy(nm, req->name, 16);
	nm[16] = 0;
	printk(KERN_DEBUG "\t1st 16 characters of name: %s\n", nm);
	}

	/**
	* ubi_dbg_dump_flash - dump a region of flash.
	* @ubi: UBI device description object
	* @pnum: the physical eraseblock number to dump
	* @offset: the starting offset within the physical eraseblock to dump
	* @len: the length of the region to dump
	*/
	void ubi_dbg_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len)
	{
	int err;
	size_t read;
	void *buf;
	loff_t addr = (loff_t)pnum * ubi->peb_size + offset;

	buf = vmalloc(len);
	if (!buf)
	return;
	err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
	if (err && err != -EUCLEAN) {
	ubi_err("error %d while reading %d bytes from PEB %d:%d, "
	"read %zd bytes", err, len, pnum, offset, read);
	goto out;
	}

	dbg_msg("dumping %d bytes of data from PEB %d, offset %d",
	len, pnum, offset);
	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
	out:
	vfree(buf);
	return;
	}

	/**
	* ubi_debugging_init_dev - initialize debugging for an UBI device.
	* @ubi: UBI device description object
	*
	* This function initializes debugging-related data for UBI device @ubi.
	* Returns zero in case of success and a negative error code in case of
	* failure.
	*/
	int ubi_debugging_init_dev(struct ubi_device *ubi)
	{
	ubi->dbg = kzalloc(sizeof(struct ubi_debug_info), GFP_KERNEL);
	if (!ubi->dbg)
	return -ENOMEM;

	return 0;
	}

	/**
	* ubi_debugging_exit_dev - free debugging data for an UBI device.
	* @ubi: UBI device description object
	*/
	void ubi_debugging_exit_dev(struct ubi_device *ubi)
	{
	kfree(ubi->dbg);
	}

	/*
	* Root directory for UBI stuff in debugfs. Contains sub-directories which
	* contain the stuff specific to particular UBI devices.
	*/
	static struct dentry *dfs_rootdir;

	/**
	* ubi_debugfs_init - create UBI debugfs directory.
	*
	* Create UBI debugfs directory. Returns zero in case of success and a negative
	* error code in case of failure.
	*/
	int ubi_debugfs_init(void)
	{
	dfs_rootdir = debugfs_create_dir("ubi", NULL);
	if (IS_ERR_OR_NULL(dfs_rootdir)) {
	int err = dfs_rootdir ? -ENODEV : PTR_ERR(dfs_rootdir);

	ubi_err("cannot create \"ubi\" debugfs directory, error %d\n",
	err);
	return err;
	}

	return 0;
	}

	/**
	* ubi_debugfs_exit - remove UBI debugfs directory.
	*/
	void ubi_debugfs_exit(void)
	{
	debugfs_remove(dfs_rootdir);
	}

	/* Read an UBI debugfs file */
	static ssize_t dfs_file_read(struct file file, char __user user_buf,
	size_t count, loff_t *ppos)
	{
	unsigned long ubi_num = (unsigned long)file->private_data;
	struct dentry *dent = file->f_path.dentry;
	struct ubi_device *ubi;
	struct ubi_debug_info *d;
	char buf[3];
	int val;

	ubi = ubi_get_device(ubi_num);
	if (!ubi)
	return -ENODEV;
	d = ubi->dbg;

	if (dent == d->dfs_chk_gen)
	val = d->chk_gen;
	else if (dent == d->dfs_chk_io)
	val = d->chk_io;
	else if (dent == d->dfs_disable_bgt)
	val = d->disable_bgt;
	else if (dent == d->dfs_emulate_bitflips)
	val = d->emulate_bitflips;
	else if (dent == d->dfs_emulate_io_failures)
	val = d->emulate_io_failures;
	else {
	count = -EINVAL;
	goto out;
	}

	if (val)
	buf[0] = '1';
	else
	buf[0] = '0';
	buf[1] = '\n';
	buf[2] = 0x00;

	count = simple_read_from_buffer(user_buf, count, ppos, buf, 2);

	out:
	ubi_put_device(ubi);
	return count;
	}

	/* Write an UBI debugfs file */
	static ssize_t dfs_file_write(struct file file, const char __user user_buf,
	size_t count, loff_t *ppos)
	{
	unsigned long ubi_num = (unsigned long)file->private_data;
	struct dentry *dent = file->f_path.dentry;
	struct ubi_device *ubi;
	struct ubi_debug_info *d;
	size_t buf_size;
	char buf[8];
	int val;

	ubi = ubi_get_device(ubi_num);
	if (!ubi)
	return -ENODEV;
	d = ubi->dbg;

	buf_size = min_t(size_t, count, (sizeof(buf) - 1));
	if (copy_from_user(buf, user_buf, buf_size)) {
	count = -EFAULT;
	goto out;
	}

	if (buf[0] == '1')
	val = 1;
	else if (buf[0] == '0')
	val = 0;
	else {
	count = -EINVAL;
	goto out;
	}

	if (dent == d->dfs_chk_gen)
	d->chk_gen = val;
	else if (dent == d->dfs_chk_io)
	d->chk_io = val;
	else if (dent == d->dfs_disable_bgt)
	d->disable_bgt = val;
	else if (dent == d->dfs_emulate_bitflips)
	d->emulate_bitflips = val;
	else if (dent == d->dfs_emulate_io_failures)
	d->emulate_io_failures = val;
	else
	count = -EINVAL;

	out:
	ubi_put_device(ubi);
	return count;
	}

	static int default_open(struct inode inode, struct file file)
	{
	if (inode->i_private)
	file->private_data = inode->i_private;

	return 0;
	}

	/* File operations for all UBI debugfs files */
	static const struct file_operations dfs_fops = {
	.read = dfs_file_read,
	.write = dfs_file_write,
	.open = default_open,
	.llseek = no_llseek,
	.owner = THIS_MODULE,
	};

	/**
	* ubi_debugfs_init_dev - initialize debugfs for an UBI device.
	* @ubi: UBI device description object
	*
	* This function creates all debugfs files for UBI device @ubi. Returns zero in
	* case of success and a negative error code in case of failure.
	*/
	int ubi_debugfs_init_dev(struct ubi_device *ubi)
	{
	int err, n;
	unsigned long ubi_num = ubi->ubi_num;
	const char *fname;
	struct dentry *dent;
	struct ubi_debug_info *d = ubi->dbg;

	n = snprintf(d->dfs_dir_name, UBI_DFS_DIR_LEN + 1, UBI_DFS_DIR_NAME,
	ubi->ubi_num);
	if (n == UBI_DFS_DIR_LEN) {
	/* The array size is too small */
	fname = UBI_DFS_DIR_NAME;
	dent = ERR_PTR(-EINVAL);
	goto out;
	}

	fname = d->dfs_dir_name;
	dent = debugfs_create_dir(fname, dfs_rootdir);
	if (IS_ERR_OR_NULL(dent))
	goto out;
	d->dfs_dir = dent;

	fname = "chk_gen";
	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
	&dfs_fops);
	if (IS_ERR_OR_NULL(dent))
	goto out_remove;
	d->dfs_chk_gen = dent;

	fname = "chk_io";
	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
	&dfs_fops);
	if (IS_ERR_OR_NULL(dent))
	goto out_remove;
	d->dfs_chk_io = dent;

	fname = "tst_disable_bgt";
	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
	&dfs_fops);
	if (IS_ERR_OR_NULL(dent))
	goto out_remove;
	d->dfs_disable_bgt = dent;

	fname = "tst_emulate_bitflips";
	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
	&dfs_fops);
	if (IS_ERR_OR_NULL(dent))
	goto out_remove;
	d->dfs_emulate_bitflips = dent;

	fname = "tst_emulate_io_failures";
	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
	&dfs_fops);
	if (IS_ERR_OR_NULL(dent))
	goto out_remove;
	d->dfs_emulate_io_failures = dent;

	return 0;

	out_remove:
	debugfs_remove_recursive(d->dfs_dir);
	out:
	err = dent ? PTR_ERR(dent) : -ENODEV;
	ubi_err("cannot create \"%s\" debugfs file or directory, error %d\n",
	fname, err);
	return err;
	}

	/**
	* dbg_debug_exit_dev - free all debugfs files corresponding to device @ubi
	* @ubi: UBI device description object
	*/
	void ubi_debugfs_exit_dev(struct ubi_device *ubi)
	{
	debugfs_remove_recursive(ubi->dbg->dfs_dir);
	}

	#endif /* CONFIG_MTD_UBI_DEBUG */