drivers/mtd/ubi/debug.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (c) International Business Machines Corp., 2006
   4  *
   5  * Author: Artem Bityutskiy (Битюцкий Артём)
   6  */
   7
   8 #include "ubi.h"
   9 #include <linux/debugfs.h>
  10 #include <linux/uaccess.h>
  11 #include <linux/module.h>
  12 #include <linux/seq_file.h>
  13 #include <linux/fault-inject.h>
  14
  15 #ifdef CONFIG_MTD_UBI_FAULT_INJECTION
  16 static DECLARE_FAULT_ATTR(fault_eccerr_attr);
  17 static DECLARE_FAULT_ATTR(fault_bitflips_attr);
  18 static DECLARE_FAULT_ATTR(fault_read_failure_attr);
  19 static DECLARE_FAULT_ATTR(fault_write_failure_attr);
  20 static DECLARE_FAULT_ATTR(fault_erase_failure_attr);
  21 static DECLARE_FAULT_ATTR(fault_power_cut_attr);
  22 static DECLARE_FAULT_ATTR(fault_io_ff_attr);
  23 static DECLARE_FAULT_ATTR(fault_io_ff_bitflips_attr);
  24 static DECLARE_FAULT_ATTR(fault_bad_hdr_attr);
  25 static DECLARE_FAULT_ATTR(fault_bad_hdr_ebadmsg_attr);
  26
  27 #define FAIL_ACTION(name, fault_attr)                   \
  28 bool should_fail_##name(void)                           \
  29 {                                                       \
  30         return should_fail(&fault_attr, 1);             \
  31 }
  32
  33 FAIL_ACTION(eccerr,             fault_eccerr_attr)
  34 FAIL_ACTION(bitflips,           fault_bitflips_attr)
  35 FAIL_ACTION(read_failure,       fault_read_failure_attr)
  36 FAIL_ACTION(write_failure,      fault_write_failure_attr)
  37 FAIL_ACTION(erase_failure,      fault_erase_failure_attr)
  38 FAIL_ACTION(power_cut,          fault_power_cut_attr)
  39 FAIL_ACTION(io_ff,              fault_io_ff_attr)
  40 FAIL_ACTION(io_ff_bitflips,     fault_io_ff_bitflips_attr)
  41 FAIL_ACTION(bad_hdr,            fault_bad_hdr_attr)
  42 FAIL_ACTION(bad_hdr_ebadmsg,    fault_bad_hdr_ebadmsg_attr)
  43 #endif
  44
  45 /**
  46  * ubi_dump_flash - dump a region of flash.
  47  * @ubi: UBI device description object
  48  * @pnum: the physical eraseblock number to dump
  49  * @offset: the starting offset within the physical eraseblock to dump
  50  * @len: the length of the region to dump
  51  */
  52 void ubi_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len)
  53 {
  54         int err;
  55         size_t read;
  56         void *buf;
  57         loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
  58
  59         buf = vmalloc(len);
  60         if (!buf)
  61                 return;
  62         err = mtd_read(ubi->mtd, addr, len, &read, buf);
  63         if (err && err != -EUCLEAN) {
  64                 ubi_err(ubi, "err %d while reading %d bytes from PEB %d:%d, read %zd bytes",
  65                         err, len, pnum, offset, read);
  66                 goto out;
  67         }
  68
  69         ubi_msg(ubi, "dumping %d bytes of data from PEB %d, offset %d",
  70                 len, pnum, offset);
  71         print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
  72 out:
  73         vfree(buf);
  74         return;
  75 }
  76
  77 /**
  78  * ubi_dump_ec_hdr - dump an erase counter header.
  79  * @ec_hdr: the erase counter header to dump
  80  */
  81 void ubi_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr)
  82 {
  83         pr_err("Erase counter header dump:\n");
  84         pr_err("\tmagic          %#08x\n", be32_to_cpu(ec_hdr->magic));
  85         pr_err("\tversion        %d\n", (int)ec_hdr->version);
  86         pr_err("\tec             %llu\n", (long long)be64_to_cpu(ec_hdr->ec));
  87         pr_err("\tvid_hdr_offset %d\n", be32_to_cpu(ec_hdr->vid_hdr_offset));
  88         pr_err("\tdata_offset    %d\n", be32_to_cpu(ec_hdr->data_offset));
  89         pr_err("\timage_seq      %d\n", be32_to_cpu(ec_hdr->image_seq));
  90         pr_err("\thdr_crc        %#08x\n", be32_to_cpu(ec_hdr->hdr_crc));
  91         pr_err("erase counter header hexdump:\n");
  92         print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
  93                        ec_hdr, UBI_EC_HDR_SIZE, 1);
  94 }
  95
  96 /**
  97  * ubi_dump_vid_hdr - dump a volume identifier header.
  98  * @vid_hdr: the volume identifier header to dump
  99  */
 100 void ubi_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr)
 101 {
 102         pr_err("Volume identifier header dump:\n");
 103         pr_err("\tmagic     %08x\n", be32_to_cpu(vid_hdr->magic));
 104         pr_err("\tversion   %d\n",  (int)vid_hdr->version);
 105         pr_err("\tvol_type  %d\n",  (int)vid_hdr->vol_type);
 106         pr_err("\tcopy_flag %d\n",  (int)vid_hdr->copy_flag);
 107         pr_err("\tcompat    %d\n",  (int)vid_hdr->compat);
 108         pr_err("\tvol_id    %d\n",  be32_to_cpu(vid_hdr->vol_id));
 109         pr_err("\tlnum      %d\n",  be32_to_cpu(vid_hdr->lnum));
 110         pr_err("\tdata_size %d\n",  be32_to_cpu(vid_hdr->data_size));
 111         pr_err("\tused_ebs  %d\n",  be32_to_cpu(vid_hdr->used_ebs));
 112         pr_err("\tdata_pad  %d\n",  be32_to_cpu(vid_hdr->data_pad));
 113         pr_err("\tsqnum     %llu\n",
 114                 (unsigned long long)be64_to_cpu(vid_hdr->sqnum));
 115         pr_err("\thdr_crc   %08x\n", be32_to_cpu(vid_hdr->hdr_crc));
 116         pr_err("Volume identifier header hexdump:\n");
 117         print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
 118                        vid_hdr, UBI_VID_HDR_SIZE, 1);
 119 }
 120
 121 /**
 122  * ubi_dump_vol_info - dump volume information.
 123  * @vol: UBI volume description object
 124  */
 125 void ubi_dump_vol_info(const struct ubi_volume *vol)
 126 {
 127         pr_err("Volume information dump:\n");
 128         pr_err("\tvol_id          %d\n", vol->vol_id);
 129         pr_err("\treserved_pebs   %d\n", vol->reserved_pebs);
 130         pr_err("\talignment       %d\n", vol->alignment);
 131         pr_err("\tdata_pad        %d\n", vol->data_pad);
 132         pr_err("\tvol_type        %d\n", vol->vol_type);
 133         pr_err("\tname_len        %d\n", vol->name_len);
 134         pr_err("\tusable_leb_size %d\n", vol->usable_leb_size);
 135         pr_err("\tused_ebs        %d\n", vol->used_ebs);
 136         pr_err("\tused_bytes      %lld\n", vol->used_bytes);
 137         pr_err("\tlast_eb_bytes   %d\n", vol->last_eb_bytes);
 138         pr_err("\tcorrupted       %d\n", vol->corrupted);
 139         pr_err("\tupd_marker      %d\n", vol->upd_marker);
 140         pr_err("\tskip_check      %d\n", vol->skip_check);
 141
 142         if (vol->name_len <= UBI_VOL_NAME_MAX &&
 143             strnlen(vol->name, vol->name_len + 1) == vol->name_len) {
 144                 pr_err("\tname            %s\n", vol->name);
 145         } else {
 146                 pr_err("\t1st 5 characters of name: %c%c%c%c%c\n",
 147                        vol->name[0], vol->name[1], vol->name[2],
 148                        vol->name[3], vol->name[4]);
 149         }
 150 }
 151
 152 /**
 153  * ubi_dump_vtbl_record - dump a &struct ubi_vtbl_record object.
 154  * @r: the object to dump
 155  * @idx: volume table index
 156  */
 157 void ubi_dump_vtbl_record(const struct ubi_vtbl_record *r, int idx)
 158 {
 159         int name_len = be16_to_cpu(r->name_len);
 160
 161         pr_err("Volume table record %d dump:\n", idx);
 162         pr_err("\treserved_pebs   %d\n", be32_to_cpu(r->reserved_pebs));
 163         pr_err("\talignment       %d\n", be32_to_cpu(r->alignment));
 164         pr_err("\tdata_pad        %d\n", be32_to_cpu(r->data_pad));
 165         pr_err("\tvol_type        %d\n", (int)r->vol_type);
 166         pr_err("\tupd_marker      %d\n", (int)r->upd_marker);
 167         pr_err("\tname_len        %d\n", name_len);
 168
 169         if (r->name[0] == '\0') {
 170                 pr_err("\tname            NULL\n");
 171                 return;
 172         }
 173
 174         if (name_len <= UBI_VOL_NAME_MAX &&
 175             strnlen(&r->name[0], name_len + 1) == name_len) {
 176                 pr_err("\tname            %s\n", &r->name[0]);
 177         } else {
 178                 pr_err("\t1st 5 characters of name: %c%c%c%c%c\n",
 179                         r->name[0], r->name[1], r->name[2], r->name[3],
 180                         r->name[4]);
 181         }
 182         pr_err("\tcrc             %#08x\n", be32_to_cpu(r->crc));
 183 }
 184
 185 /**
 186  * ubi_dump_av - dump a &struct ubi_ainf_volume object.
 187  * @av: the object to dump
 188  */
 189 void ubi_dump_av(const struct ubi_ainf_volume *av)
 190 {
 191         pr_err("Volume attaching information dump:\n");
 192         pr_err("\tvol_id         %d\n", av->vol_id);
 193         pr_err("\thighest_lnum   %d\n", av->highest_lnum);
 194         pr_err("\tleb_count      %d\n", av->leb_count);
 195         pr_err("\tcompat         %d\n", av->compat);
 196         pr_err("\tvol_type       %d\n", av->vol_type);
 197         pr_err("\tused_ebs       %d\n", av->used_ebs);
 198         pr_err("\tlast_data_size %d\n", av->last_data_size);
 199         pr_err("\tdata_pad       %d\n", av->data_pad);
 200 }
 201
 202 /**
 203  * ubi_dump_aeb - dump a &struct ubi_ainf_peb object.
 204  * @aeb: the object to dump
 205  * @type: object type: 0 - not corrupted, 1 - corrupted
 206  */
 207 void ubi_dump_aeb(const struct ubi_ainf_peb *aeb, int type)
 208 {
 209         pr_err("eraseblock attaching information dump:\n");
 210         pr_err("\tec       %d\n", aeb->ec);
 211         pr_err("\tpnum     %d\n", aeb->pnum);
 212         if (type == 0) {
 213                 pr_err("\tlnum     %d\n", aeb->lnum);
 214                 pr_err("\tscrub    %d\n", aeb->scrub);
 215                 pr_err("\tsqnum    %llu\n", aeb->sqnum);
 216         }
 217 }
 218
 219 /**
 220  * ubi_dump_mkvol_req - dump a &struct ubi_mkvol_req object.
 221  * @req: the object to dump
 222  */
 223 void ubi_dump_mkvol_req(const struct ubi_mkvol_req *req)
 224 {
 225         char nm[17];
 226
 227         pr_err("Volume creation request dump:\n");
 228         pr_err("\tvol_id    %d\n",   req->vol_id);
 229         pr_err("\talignment %d\n",   req->alignment);
 230         pr_err("\tbytes     %lld\n", (long long)req->bytes);
 231         pr_err("\tvol_type  %d\n",   req->vol_type);
 232         pr_err("\tname_len  %d\n",   req->name_len);
 233
 234         memcpy(nm, req->name, 16);
 235         nm[16] = 0;
 236         pr_err("\t1st 16 characters of name: %s\n", nm);
 237 }
 238
 239 /*
 240  * Root directory for UBI stuff in debugfs. Contains sub-directories which
 241  * contain the stuff specific to particular UBI devices.
 242  */
 243 static struct dentry *dfs_rootdir;
 244
 245 #ifdef CONFIG_MTD_UBI_FAULT_INJECTION
 246 static void dfs_create_fault_entry(struct dentry *parent)
 247 {
 248         struct dentry *dir;
 249
 250         dir = debugfs_create_dir("fault_inject", parent);
 251         if (IS_ERR_OR_NULL(dir)) {
 252                 int err = dir ? PTR_ERR(dir) : -ENODEV;
 253
 254                 pr_warn("UBI error: cannot create \"fault_inject\" debugfs directory, error %d\n",
 255                          err);
 256                 return;
 257         }
 258
 259         fault_create_debugfs_attr("emulate_eccerr", dir,
 260                                   &fault_eccerr_attr);
 261
 262         fault_create_debugfs_attr("emulate_read_failure", dir,
 263                                   &fault_read_failure_attr);
 264
 265         fault_create_debugfs_attr("emulate_bitflips", dir,
 266                                   &fault_bitflips_attr);
 267
 268         fault_create_debugfs_attr("emulate_write_failure", dir,
 269                                   &fault_write_failure_attr);
 270
 271         fault_create_debugfs_attr("emulate_erase_failure", dir,
 272                                   &fault_erase_failure_attr);
 273
 274         fault_create_debugfs_attr("emulate_power_cut", dir,
 275                                   &fault_power_cut_attr);
 276
 277         fault_create_debugfs_attr("emulate_io_ff", dir,
 278                                   &fault_io_ff_attr);
 279
 280         fault_create_debugfs_attr("emulate_io_ff_bitflips", dir,
 281                                   &fault_io_ff_bitflips_attr);
 282
 283         fault_create_debugfs_attr("emulate_bad_hdr", dir,
 284                                   &fault_bad_hdr_attr);
 285
 286         fault_create_debugfs_attr("emulate_bad_hdr_ebadmsg", dir,
 287                                   &fault_bad_hdr_ebadmsg_attr);
 288 }
 289 #endif
 290
 291 /**
 292  * ubi_debugfs_init - create UBI debugfs directory.
 293  *
 294  * Create UBI debugfs directory. Returns zero in case of success and a negative
 295  * error code in case of failure.
 296  */
 297 int ubi_debugfs_init(void)
 298 {
 299         if (!IS_ENABLED(CONFIG_DEBUG_FS))
 300                 return 0;
 301
 302         dfs_rootdir = debugfs_create_dir("ubi", NULL);
 303         if (IS_ERR_OR_NULL(dfs_rootdir)) {
 304                 int err = dfs_rootdir ? PTR_ERR(dfs_rootdir) : -ENODEV;
 305
 306                 pr_err("UBI error: cannot create \"ubi\" debugfs directory, error %d\n",
 307                        err);
 308                 return err;
 309         }
 310
 311 #ifdef CONFIG_MTD_UBI_FAULT_INJECTION
 312         dfs_create_fault_entry(dfs_rootdir);
 313 #endif
 314
 315         return 0;
 316 }
 317
 318 /**
 319  * ubi_debugfs_exit - remove UBI debugfs directory.
 320  */
 321 void ubi_debugfs_exit(void)
 322 {
 323         if (IS_ENABLED(CONFIG_DEBUG_FS))
 324                 debugfs_remove(dfs_rootdir);
 325 }
 326
 327 /* Read an UBI debugfs file */
 328 static ssize_t dfs_file_read(struct file *file, char __user *user_buf,
 329                              size_t count, loff_t *ppos)
 330 {
 331         unsigned long ubi_num = (unsigned long)file->private_data;
 332         struct dentry *dent = file->f_path.dentry;
 333         struct ubi_device *ubi;
 334         struct ubi_debug_info *d;
 335         char buf[16];
 336         int val;
 337
 338         ubi = ubi_get_device(ubi_num);
 339         if (!ubi)
 340                 return -ENODEV;
 341         d = &ubi->dbg;
 342
 343         if (dent == d->dfs_chk_gen)
 344                 val = d->chk_gen;
 345         else if (dent == d->dfs_chk_io)
 346                 val = d->chk_io;
 347         else if (dent == d->dfs_chk_fastmap)
 348                 val = d->chk_fastmap;
 349         else if (dent == d->dfs_disable_bgt)
 350                 val = d->disable_bgt;
 351         else if (dent == d->dfs_emulate_bitflips)
 352                 val = d->emulate_bitflips;
 353         else if (dent == d->dfs_emulate_io_failures)
 354                 val = d->emulate_io_failures;
 355         else if (dent == d->dfs_emulate_failures) {
 356                 snprintf(buf, sizeof(buf), "0x%04x\n", d->emulate_failures);
 357                 count = simple_read_from_buffer(user_buf, count, ppos,
 358                                                 buf, strlen(buf));
 359                 goto out;
 360         } else if (dent == d->dfs_emulate_power_cut) {
 361                 snprintf(buf, sizeof(buf), "%u\n", d->emulate_power_cut);
 362                 count = simple_read_from_buffer(user_buf, count, ppos,
 363                                                 buf, strlen(buf));
 364                 goto out;
 365         } else if (dent == d->dfs_power_cut_min) {
 366                 snprintf(buf, sizeof(buf), "%u\n", d->power_cut_min);
 367                 count = simple_read_from_buffer(user_buf, count, ppos,
 368                                                 buf, strlen(buf));
 369                 goto out;
 370         } else if (dent == d->dfs_power_cut_max) {
 371                 snprintf(buf, sizeof(buf), "%u\n", d->power_cut_max);
 372                 count = simple_read_from_buffer(user_buf, count, ppos,
 373                                                 buf, strlen(buf));
 374                 goto out;
 375         } else {
 376                 count = -EINVAL;
 377                 goto out;
 378         }
 379
 380         if (val)
 381                 buf[0] = '1';
 382         else
 383                 buf[0] = '0';
 384         buf[1] = '\n';
 385         buf[2] = 0x00;
 386
 387         count = simple_read_from_buffer(user_buf, count, ppos, buf, 2);
 388
 389 out:
 390         ubi_put_device(ubi);
 391         return count;
 392 }
 393
 394 /* Write an UBI debugfs file */
 395 static ssize_t dfs_file_write(struct file *file, const char __user *user_buf,
 396                               size_t count, loff_t *ppos)
 397 {
 398         unsigned long ubi_num = (unsigned long)file->private_data;
 399         struct dentry *dent = file->f_path.dentry;
 400         struct ubi_device *ubi;
 401         struct ubi_debug_info *d;
 402         size_t buf_size;
 403         char buf[16] = {0};
 404         int val;
 405
 406         ubi = ubi_get_device(ubi_num);
 407         if (!ubi)
 408                 return -ENODEV;
 409         d = &ubi->dbg;
 410
 411         buf_size = min_t(size_t, count, (sizeof(buf) - 1));
 412         if (copy_from_user(buf, user_buf, buf_size)) {
 413                 count = -EFAULT;
 414                 goto out;
 415         }
 416
 417         if (dent == d->dfs_emulate_failures) {
 418                 if (kstrtouint(buf, 0, &d->emulate_failures) != 0)
 419                         count = -EINVAL;
 420                 goto out;
 421         } else if (dent == d->dfs_power_cut_min) {
 422                 if (kstrtouint(buf, 0, &d->power_cut_min) != 0)
 423                         count = -EINVAL;
 424                 goto out;
 425         } else if (dent == d->dfs_power_cut_max) {
 426                 if (kstrtouint(buf, 0, &d->power_cut_max) != 0)
 427                         count = -EINVAL;
 428                 goto out;
 429         } else if (dent == d->dfs_emulate_power_cut) {
 430                 if (kstrtoint(buf, 0, &val) != 0)
 431                         count = -EINVAL;
 432                 else
 433                         d->emulate_power_cut = val;
 434                 goto out;
 435         }
 436
 437         if (buf[0] == '1')
 438                 val = 1;
 439         else if (buf[0] == '0')
 440                 val = 0;
 441         else {
 442                 count = -EINVAL;
 443                 goto out;
 444         }
 445
 446         if (dent == d->dfs_chk_gen)
 447                 d->chk_gen = val;
 448         else if (dent == d->dfs_chk_io)
 449                 d->chk_io = val;
 450         else if (dent == d->dfs_chk_fastmap)
 451                 d->chk_fastmap = val;
 452         else if (dent == d->dfs_disable_bgt)
 453                 d->disable_bgt = val;
 454         else if (dent == d->dfs_emulate_bitflips)
 455                 d->emulate_bitflips = val;
 456         else if (dent == d->dfs_emulate_io_failures)
 457                 d->emulate_io_failures = val;
 458         else
 459                 count = -EINVAL;
 460
 461 out:
 462         ubi_put_device(ubi);
 463         return count;
 464 }
 465
 466 /* File operations for all UBI debugfs files except
 467  * detailed_erase_block_info
 468  */
 469 static const struct file_operations dfs_fops = {
 470         .read   = dfs_file_read,
 471         .write  = dfs_file_write,
 472         .open   = simple_open,
 473         .llseek = no_llseek,
 474         .owner  = THIS_MODULE,
 475 };
 476
 477 /* As long as the position is less then that total number of erase blocks,
 478  * we still have more to print.
 479  */
 480 static void *eraseblk_count_seq_start(struct seq_file *s, loff_t *pos)
 481 {
 482         struct ubi_device *ubi = s->private;
 483
 484         if (*pos < ubi->peb_count)
 485                 return pos;
 486
 487         return NULL;
 488 }
 489
 490 /* Since we are using the position as the iterator, we just need to check if we
 491  * are done and increment the position.
 492  */
 493 static void *eraseblk_count_seq_next(struct seq_file *s, void *v, loff_t *pos)
 494 {
 495         struct ubi_device *ubi = s->private;
 496
 497         (*pos)++;
 498
 499         if (*pos < ubi->peb_count)
 500                 return pos;
 501
 502         return NULL;
 503 }
 504
 505 static void eraseblk_count_seq_stop(struct seq_file *s, void *v)
 506 {
 507 }
 508
 509 static int eraseblk_count_seq_show(struct seq_file *s, void *iter)
 510 {
 511         struct ubi_device *ubi = s->private;
 512         struct ubi_wl_entry *wl;
 513         int *block_number = iter;
 514         int erase_count = -1;
 515         int err;
 516
 517         /* If this is the start, print a header */
 518         if (*block_number == 0)
 519                 seq_puts(s, "physical_block_number\terase_count\n");
 520
 521         err = ubi_io_is_bad(ubi, *block_number);
 522         if (err)
 523                 return err;
 524
 525         spin_lock(&ubi->wl_lock);
 526
 527         wl = ubi->lookuptbl[*block_number];
 528         if (wl)
 529                 erase_count = wl->ec;
 530
 531         spin_unlock(&ubi->wl_lock);
 532
 533         if (erase_count < 0)
 534                 return 0;
 535
 536         seq_printf(s, "%-22d\t%-11d\n", *block_number, erase_count);
 537
 538         return 0;
 539 }
 540
 541 static const struct seq_operations eraseblk_count_seq_ops = {
 542         .start = eraseblk_count_seq_start,
 543         .next = eraseblk_count_seq_next,
 544         .stop = eraseblk_count_seq_stop,
 545         .show = eraseblk_count_seq_show
 546 };
 547
 548 static int eraseblk_count_open(struct inode *inode, struct file *f)
 549 {
 550         struct seq_file *s;
 551         int err;
 552
 553         err = seq_open(f, &eraseblk_count_seq_ops);
 554         if (err)
 555                 return err;
 556
 557         s = f->private_data;
 558         s->private = ubi_get_device((unsigned long)inode->i_private);
 559
 560         if (!s->private)
 561                 return -ENODEV;
 562         else
 563                 return 0;
 564 }
 565
 566 static int eraseblk_count_release(struct inode *inode, struct file *f)
 567 {
 568         struct seq_file *s = f->private_data;
 569         struct ubi_device *ubi = s->private;
 570
 571         ubi_put_device(ubi);
 572
 573         return seq_release(inode, f);
 574 }
 575
 576 static const struct file_operations eraseblk_count_fops = {
 577         .owner = THIS_MODULE,
 578         .open = eraseblk_count_open,
 579         .read = seq_read,
 580         .llseek = seq_lseek,
 581         .release = eraseblk_count_release,
 582 };
 583
 584 /**
 585  * ubi_debugfs_init_dev - initialize debugfs for an UBI device.
 586  * @ubi: UBI device description object
 587  *
 588  * This function creates all debugfs files for UBI device @ubi. Returns zero in
 589  * case of success and a negative error code in case of failure.
 590  */
 591 int ubi_debugfs_init_dev(struct ubi_device *ubi)
 592 {
 593         unsigned long ubi_num = ubi->ubi_num;
 594         struct ubi_debug_info *d = &ubi->dbg;
 595         umode_t mode = S_IRUSR | S_IWUSR;
 596         int n;
 597
 598         if (!IS_ENABLED(CONFIG_DEBUG_FS))
 599                 return 0;
 600
 601         n = snprintf(d->dfs_dir_name, UBI_DFS_DIR_LEN + 1, UBI_DFS_DIR_NAME,
 602                      ubi->ubi_num);
 603         if (n > UBI_DFS_DIR_LEN) {
 604                 /* The array size is too small */
 605                 return -EINVAL;
 606         }
 607
 608         d->dfs_dir = debugfs_create_dir(d->dfs_dir_name, dfs_rootdir);
 609
 610         d->dfs_chk_gen = debugfs_create_file("chk_gen", mode, d->dfs_dir,
 611                                              (void *)ubi_num, &dfs_fops);
 612
 613         d->dfs_chk_io = debugfs_create_file("chk_io", mode, d->dfs_dir,
 614                                             (void *)ubi_num, &dfs_fops);
 615
 616         d->dfs_chk_fastmap = debugfs_create_file("chk_fastmap", mode,
 617                                                  d->dfs_dir, (void *)ubi_num,
 618                                                  &dfs_fops);
 619
 620         d->dfs_disable_bgt = debugfs_create_file("tst_disable_bgt", mode,
 621                                                  d->dfs_dir, (void *)ubi_num,
 622                                                  &dfs_fops);
 623
 624         d->dfs_emulate_bitflips = debugfs_create_file("tst_emulate_bitflips",
 625                                                       mode, d->dfs_dir,
 626                                                       (void *)ubi_num,
 627                                                       &dfs_fops);
 628
 629         d->dfs_emulate_io_failures = debugfs_create_file("tst_emulate_io_failures",
 630                                                          mode, d->dfs_dir,
 631                                                          (void *)ubi_num,
 632                                                          &dfs_fops);
 633
 634         d->dfs_emulate_power_cut = debugfs_create_file("tst_emulate_power_cut",
 635                                                        mode, d->dfs_dir,
 636                                                        (void *)ubi_num,
 637                                                        &dfs_fops);
 638
 639         d->dfs_power_cut_min = debugfs_create_file("tst_emulate_power_cut_min",
 640                                                    mode, d->dfs_dir,
 641                                                    (void *)ubi_num, &dfs_fops);
 642
 643         d->dfs_power_cut_max = debugfs_create_file("tst_emulate_power_cut_max",
 644                                                    mode, d->dfs_dir,
 645                                                    (void *)ubi_num, &dfs_fops);
 646
 647         debugfs_create_file("detailed_erase_block_info", S_IRUSR, d->dfs_dir,
 648                             (void *)ubi_num, &eraseblk_count_fops);
 649
 650 #ifdef CONFIG_MTD_UBI_FAULT_INJECTION
 651         d->dfs_emulate_failures = debugfs_create_file("emulate_failures",
 652                                                        mode, d->dfs_dir,
 653                                                        (void *)ubi_num,
 654                                                        &dfs_fops);
 655 #endif
 656         return 0;
 657 }
 658
 659 /**
 660  * ubi_debugfs_exit_dev - free all debugfs files corresponding to device @ubi
 661  * @ubi: UBI device description object
 662  */
 663 void ubi_debugfs_exit_dev(struct ubi_device *ubi)
 664 {
 665         if (IS_ENABLED(CONFIG_DEBUG_FS))
 666                 debugfs_remove_recursive(ubi->dbg.dfs_dir);
 667 }
 668
 669 /**
 670  * ubi_dbg_power_cut - emulate a power cut if it is time to do so
 671  * @ubi: UBI device description object
 672  * @caller: Flags set to indicate from where the function is being called
 673  *
 674  * Returns non-zero if a power cut was emulated, zero if not.
 675  */
 676 int ubi_dbg_power_cut(struct ubi_device *ubi, int caller)
 677 {
 678         unsigned int range;
 679
 680         if ((ubi->dbg.emulate_power_cut & caller) == 0)
 681                 return 0;
 682
 683         if (ubi->dbg.power_cut_counter == 0) {
 684                 ubi->dbg.power_cut_counter = ubi->dbg.power_cut_min;
 685
 686                 if (ubi->dbg.power_cut_max > ubi->dbg.power_cut_min) {
 687                         range = ubi->dbg.power_cut_max - ubi->dbg.power_cut_min;
 688                         ubi->dbg.power_cut_counter += get_random_u32_below(range);
 689                 }
 690                 return 0;
 691         }
 692
 693         ubi->dbg.power_cut_counter--;
 694         if (ubi->dbg.power_cut_counter)
 695                 return 0;
 696
 697         return 1;
 698 }