cmds-scrub.c

   1 /*
   2  * Copyright (C) 2011 STRATO.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include "kerncompat.h"
  20
  21 #include <sys/ioctl.h>
  22 #include <sys/wait.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <sys/socket.h>
  26 #include <sys/un.h>
  27 #include <sys/syscall.h>
  28 #include <poll.h>
  29 #include <sys/file.h>
  30 #include <uuid/uuid.h>
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33 #include <pthread.h>
  34 #include <ctype.h>
  35 #include <signal.h>
  36 #include <stdarg.h>
  37
  38 #include "ctree.h"
  39 #include "ioctl.h"
  40 #include "utils.h"
  41 #include "volumes.h"
  42 #include "disk-io.h"
  43
  44 #include "commands.h"
  45
  46 static const char * const scrub_cmd_group_usage[] = {
  47         "btrfs scrub <command> [options] <path>|<device>",
  48         NULL
  49 };
  50
  51 #define SCRUB_DATA_FILE "/var/lib/btrfs/scrub.status"
  52 #define SCRUB_PROGRESS_SOCKET_PATH "/var/lib/btrfs/scrub.progress"
  53 #define SCRUB_FILE_VERSION_PREFIX "scrub status"
  54 #define SCRUB_FILE_VERSION "1"
  55
  56 struct scrub_stats {
  57         time_t t_start;
  58         time_t t_resumed;
  59         u64 duration;
  60         u64 finished;
  61         u64 canceled;
  62 };
  63
  64 /* TBD: replace with #include "linux/ioprio.h" in some years */
  65 #if !defined (IOPRIO_H)
  66 #define IOPRIO_WHO_PROCESS 1
  67 #define IOPRIO_CLASS_SHIFT 13
  68 #define IOPRIO_PRIO_VALUE(class, data) \
  69                 (((class) << IOPRIO_CLASS_SHIFT) | (data))
  70 #define IOPRIO_CLASS_IDLE 3
  71 #endif
  72
  73 struct scrub_progress {
  74         struct btrfs_ioctl_scrub_args scrub_args;
  75         int fd;
  76         int ret;
  77         int skip;
  78         struct scrub_stats stats;
  79         struct scrub_file_record *resumed;
  80         int ioctl_errno;
  81         pthread_mutex_t progress_mutex;
  82         int ioprio_class;
  83         int ioprio_classdata;
  84 };
  85
  86 struct scrub_file_record {
  87         u8 fsid[BTRFS_FSID_SIZE];
  88         u64 devid;
  89         struct scrub_stats stats;
  90         struct btrfs_scrub_progress p;
  91 };
  92
  93 struct scrub_progress_cycle {
  94         int fdmnt;
  95         int prg_fd;
  96         int do_record;
  97         struct btrfs_ioctl_fs_info_args *fi;
  98         struct scrub_progress *progress;
  99         struct scrub_progress *shared_progress;
 100         pthread_mutex_t *write_mutex;
 101 };
 102
 103 struct scrub_fs_stat {
 104         struct btrfs_scrub_progress p;
 105         struct scrub_stats s;
 106         int i;
 107 };
 108
 109 static void print_scrub_full(struct btrfs_scrub_progress *sp)
 110 {
 111         printf("\tdata_extents_scrubbed: %lld\n", sp->data_extents_scrubbed);
 112         printf("\ttree_extents_scrubbed: %lld\n", sp->tree_extents_scrubbed);
 113         printf("\tdata_bytes_scrubbed: %lld\n", sp->data_bytes_scrubbed);
 114         printf("\ttree_bytes_scrubbed: %lld\n", sp->tree_bytes_scrubbed);
 115         printf("\tread_errors: %lld\n", sp->read_errors);
 116         printf("\tcsum_errors: %lld\n", sp->csum_errors);
 117         printf("\tverify_errors: %lld\n", sp->verify_errors);
 118         printf("\tno_csum: %lld\n", sp->no_csum);
 119         printf("\tcsum_discards: %lld\n", sp->csum_discards);
 120         printf("\tsuper_errors: %lld\n", sp->super_errors);
 121         printf("\tmalloc_errors: %lld\n", sp->malloc_errors);
 122         printf("\tuncorrectable_errors: %lld\n", sp->uncorrectable_errors);
 123         printf("\tunverified_errors: %lld\n", sp->unverified_errors);
 124         printf("\tcorrected_errors: %lld\n", sp->corrected_errors);
 125         printf("\tlast_physical: %lld\n", sp->last_physical);
 126 }
 127
 128 #define ERR(test, ...) do {                     \
 129         if (test)                               \
 130                 fprintf(stderr, __VA_ARGS__);   \
 131 } while (0)
 132
 133 #define PRINT_SCRUB_ERROR(test, desc) do {      \
 134         if (test)                               \
 135                 printf(" %s=%llu", desc, test); \
 136 } while (0)
 137
 138 static void print_scrub_summary(struct btrfs_scrub_progress *p)
 139 {
 140         u64 err_cnt;
 141         u64 err_cnt2;
 142
 143         err_cnt = p->read_errors +
 144                         p->csum_errors +
 145                         p->verify_errors +
 146                         p->super_errors;
 147
 148         err_cnt2 = p->corrected_errors + p->uncorrectable_errors;
 149
 150         if (p->malloc_errors)
 151                 printf("*** WARNING: memory allocation failed while scrubbing. "
 152                        "results may be inaccurate\n");
 153
 154         printf("\ttotal bytes scrubbed: %s with %llu errors\n",
 155                 pretty_size(p->data_bytes_scrubbed + p->tree_bytes_scrubbed),
 156                 max(err_cnt, err_cnt2));
 157
 158         if (err_cnt || err_cnt2) {
 159                 printf("\terror details:");
 160                 PRINT_SCRUB_ERROR(p->read_errors, "read");
 161                 PRINT_SCRUB_ERROR(p->super_errors, "super");
 162                 PRINT_SCRUB_ERROR(p->verify_errors, "verify");
 163                 PRINT_SCRUB_ERROR(p->csum_errors, "csum");
 164                 printf("\n");
 165                 printf("\tcorrected errors: %llu, uncorrectable errors: %llu, "
 166                         "unverified errors: %llu\n", p->corrected_errors,
 167                         p->uncorrectable_errors, p->unverified_errors);
 168         }
 169 }
 170
 171 #define _SCRUB_FS_STAT(p, name, fs_stat) do {   \
 172         fs_stat->p.name += p->name;             \
 173 } while (0)
 174
 175 #define _SCRUB_FS_STAT_MIN(ss, name, fs_stat)   \
 176 do {                                            \
 177         if (fs_stat->s.name > ss->name) {       \
 178                 fs_stat->s.name = ss->name;     \
 179         }                                       \
 180 } while (0)
 181
 182 #define _SCRUB_FS_STAT_ZMIN(ss, name, fs_stat)                  \
 183 do {                                                            \
 184         if (!fs_stat->s.name || fs_stat->s.name > ss->name) {   \
 185                 fs_stat->s.name = ss->name;                     \
 186         }                                                       \
 187 } while (0)
 188
 189 #define _SCRUB_FS_STAT_ZMAX(ss, name, fs_stat)                          \
 190 do {                                                                    \
 191         if (!(fs_stat)->s.name || (fs_stat)->s.name < (ss)->name) {     \
 192                 (fs_stat)->s.name = (ss)->name;                         \
 193         }                                                               \
 194 } while (0)
 195
 196 static void add_to_fs_stat(struct btrfs_scrub_progress *p,
 197                                 struct scrub_stats *ss,
 198                                 struct scrub_fs_stat *fs_stat)
 199 {
 200         _SCRUB_FS_STAT(p, data_extents_scrubbed, fs_stat);
 201         _SCRUB_FS_STAT(p, tree_extents_scrubbed, fs_stat);
 202         _SCRUB_FS_STAT(p, data_bytes_scrubbed, fs_stat);
 203         _SCRUB_FS_STAT(p, tree_bytes_scrubbed, fs_stat);
 204         _SCRUB_FS_STAT(p, read_errors, fs_stat);
 205         _SCRUB_FS_STAT(p, csum_errors, fs_stat);
 206         _SCRUB_FS_STAT(p, verify_errors, fs_stat);
 207         _SCRUB_FS_STAT(p, no_csum, fs_stat);
 208         _SCRUB_FS_STAT(p, csum_discards, fs_stat);
 209         _SCRUB_FS_STAT(p, super_errors, fs_stat);
 210         _SCRUB_FS_STAT(p, malloc_errors, fs_stat);
 211         _SCRUB_FS_STAT(p, uncorrectable_errors, fs_stat);
 212         _SCRUB_FS_STAT(p, corrected_errors, fs_stat);
 213         _SCRUB_FS_STAT(p, last_physical, fs_stat);
 214         _SCRUB_FS_STAT_ZMIN(ss, t_start, fs_stat);
 215         _SCRUB_FS_STAT_ZMIN(ss, t_resumed, fs_stat);
 216         _SCRUB_FS_STAT_ZMAX(ss, duration, fs_stat);
 217         _SCRUB_FS_STAT_ZMAX(ss, canceled, fs_stat);
 218         _SCRUB_FS_STAT_MIN(ss, finished, fs_stat);
 219 }
 220
 221 static void init_fs_stat(struct scrub_fs_stat *fs_stat)
 222 {
 223         memset(fs_stat, 0, sizeof(*fs_stat));
 224         fs_stat->s.finished = 1;
 225 }
 226
 227 static void _print_scrub_ss(struct scrub_stats *ss)
 228 {
 229         char t[4096];
 230         struct tm tm;
 231
 232         if (!ss || !ss->t_start) {
 233                 printf("\tno stats available\n");
 234                 return;
 235         }
 236         if (ss->t_resumed) {
 237                 localtime_r(&ss->t_resumed, &tm);
 238                 strftime(t, sizeof(t), "%c", &tm);
 239                 t[sizeof(t) - 1] = '\0';
 240                 printf("\tscrub resumed at %s", t);
 241         } else {
 242                 localtime_r(&ss->t_start, &tm);
 243                 strftime(t, sizeof(t), "%c", &tm);
 244                 t[sizeof(t) - 1] = '\0';
 245                 printf("\tscrub started at %s", t);
 246         }
 247         if (ss->finished && !ss->canceled) {
 248                 printf(" and finished after %llu seconds\n",
 249                        ss->duration);
 250         } else if (ss->canceled) {
 251                 printf(" and was aborted after %llu seconds\n",
 252                        ss->duration);
 253         } else {
 254                 printf(", running for %llu seconds\n", ss->duration);
 255         }
 256 }
 257
 258 static void print_scrub_dev(struct btrfs_ioctl_dev_info_args *di,
 259                                 struct btrfs_scrub_progress *p, int raw,
 260                                 const char *append, struct scrub_stats *ss)
 261 {
 262         printf("scrub device %s (id %llu) %s\n", di->path, di->devid,
 263                append ? append : "");
 264
 265         _print_scrub_ss(ss);
 266
 267         if (p) {
 268                 if (raw)
 269                         print_scrub_full(p);
 270                 else
 271                         print_scrub_summary(p);
 272         }
 273 }
 274
 275 static void print_fs_stat(struct scrub_fs_stat *fs_stat, int raw)
 276 {
 277         _print_scrub_ss(&fs_stat->s);
 278
 279         if (raw)
 280                 print_scrub_full(&fs_stat->p);
 281         else
 282                 print_scrub_summary(&fs_stat->p);
 283 }
 284
 285 static void free_history(struct scrub_file_record **last_scrubs)
 286 {
 287         struct scrub_file_record **l = last_scrubs;
 288         if (!l)
 289                 return;
 290         while (*l)
 291                 free(*l++);
 292         free(last_scrubs);
 293 }
 294
 295 /*
 296  * cancels a running scrub and makes the master process record the current
 297  * progress status before exiting.
 298  */
 299 static int cancel_fd = -1;
 300 static void scrub_sigint_record_progress(int signal)
 301 {
 302         int ret;
 303
 304         ret = ioctl(cancel_fd, BTRFS_IOC_SCRUB_CANCEL, NULL);
 305         if (ret < 0)
 306                 perror("Scrub cancel failed");
 307 }
 308
 309 static int scrub_handle_sigint_parent(void)
 310 {
 311         struct sigaction sa = {
 312                 .sa_handler = SIG_IGN,
 313                 .sa_flags = SA_RESTART,
 314         };
 315
 316         return sigaction(SIGINT, &sa, NULL);
 317 }
 318
 319 static int scrub_handle_sigint_child(int fd)
 320 {
 321         struct sigaction sa = {
 322                 .sa_handler = fd == -1 ? SIG_DFL : scrub_sigint_record_progress,
 323         };
 324
 325         cancel_fd = fd;
 326         return sigaction(SIGINT, &sa, NULL);
 327 }
 328
 329 static int scrub_datafile(const char *fn_base, const char *fn_local,
 330                                 const char *fn_tmp, char *datafile, int size)
 331 {
 332         int ret;
 333         int end = size - 2;
 334
 335         datafile[end + 1] = '\0';
 336         strncpy(datafile, fn_base, end);
 337         ret = strlen(datafile);
 338
 339         if (ret + 1 > end)
 340                 return -EOVERFLOW;
 341
 342         datafile[ret] = '.';
 343         strncpy(datafile + ret + 1, fn_local, end - ret - 1);
 344         ret = strlen(datafile);
 345
 346         if (ret + 1 > end)
 347                 return -EOVERFLOW;
 348
 349         if (fn_tmp) {
 350                 datafile[ret] = '_';
 351                 strncpy(datafile + ret + 1, fn_tmp, end - ret - 1);
 352                 ret = strlen(datafile);
 353
 354                 if (ret > end)
 355                         return -EOVERFLOW;
 356         }
 357
 358         return 0;
 359 }
 360
 361 static int scrub_open_file(const char *datafile, int m)
 362 {
 363         int fd;
 364         int ret;
 365
 366         fd = open(datafile, m, 0600);
 367         if (fd < 0)
 368                 return -errno;
 369
 370         ret = flock(fd, LOCK_EX|LOCK_NB);
 371         if (ret) {
 372                 ret = errno;
 373                 close(fd);
 374                 return -ret;
 375         }
 376
 377         return fd;
 378 }
 379
 380 static int scrub_open_file_r(const char *fn_base, const char *fn_local)
 381 {
 382         int ret;
 383         char datafile[BTRFS_PATH_NAME_MAX + 1];
 384         ret = scrub_datafile(fn_base, fn_local, NULL,
 385                                 datafile, sizeof(datafile));
 386         if (ret < 0)
 387                 return ret;
 388         return scrub_open_file(datafile, O_RDONLY);
 389 }
 390
 391 static int scrub_open_file_w(const char *fn_base, const char *fn_local,
 392                                 const char *tmp)
 393 {
 394         int ret;
 395         char datafile[BTRFS_PATH_NAME_MAX + 1];
 396         ret = scrub_datafile(fn_base, fn_local, tmp,
 397                                 datafile, sizeof(datafile));
 398         if (ret < 0)
 399                 return ret;
 400         return scrub_open_file(datafile, O_WRONLY|O_CREAT);
 401 }
 402
 403 static int scrub_rename_file(const char *fn_base, const char *fn_local,
 404                                 const char *tmp)
 405 {
 406         int ret;
 407         char datafile_old[BTRFS_PATH_NAME_MAX + 1];
 408         char datafile_new[BTRFS_PATH_NAME_MAX + 1];
 409         ret = scrub_datafile(fn_base, fn_local, tmp,
 410                                 datafile_old, sizeof(datafile_old));
 411         if (ret < 0)
 412                 return ret;
 413         ret = scrub_datafile(fn_base, fn_local, NULL,
 414                                 datafile_new, sizeof(datafile_new));
 415         if (ret < 0)
 416                 return ret;
 417         ret = rename(datafile_old, datafile_new);
 418         return ret ? -errno : 0;
 419 }
 420
 421 #define _SCRUB_KVREAD(ret, i, name, avail, l, dest) if (ret == 0) {       \
 422         ret = scrub_kvread(i, sizeof(#name), avail, l, #name, dest.name); \
 423 }
 424
 425 /*
 426  * returns 0 if the key did not match (nothing was read)
 427  *         1 if the key did match (success)
 428  *        -1 if the key did match and an error occured
 429  */
 430 static int scrub_kvread(int *i, int len, int avail, const char *buf,
 431                         const char *key, u64 *dest)
 432 {
 433         int j;
 434
 435         if (*i + len + 1 < avail && strncmp(&buf[*i], key, len - 1) == 0) {
 436                 *i += len - 1;
 437                 if (buf[*i] != ':')
 438                         return -1;
 439                 *i += 1;
 440                 for (j = 0; isdigit(buf[*i + j]) && *i + j < avail; ++j)
 441                         ;
 442                 if (*i + j >= avail)
 443                         return -1;
 444                 *dest = atoll(&buf[*i]);
 445                 *i += j;
 446                 return 1;
 447         }
 448
 449         return 0;
 450 }
 451
 452 #define _SCRUB_INVALID do {                                             \
 453         if (report_errors)                                              \
 454                 fprintf(stderr, "WARNING: invalid data in line %d pos " \
 455                         "%d state %d (near \"%.*s\") at %s:%d\n",       \
 456                         lineno, i, state, 20 > avail ? avail : 20,      \
 457                         l + i,  __FILE__, __LINE__);                    \
 458         goto skip;                                                      \
 459 } while (0)
 460
 461 static struct scrub_file_record **scrub_read_file(int fd, int report_errors)
 462 {
 463         int avail = 0;
 464         int old_avail = 0;
 465         char l[16 * 1024];
 466         int state = 0;
 467         int curr = -1;
 468         int i = 0;
 469         int j;
 470         int ret;
 471         int eof = 0;
 472         int lineno = 0;
 473         u64 version;
 474         char empty_uuid[BTRFS_FSID_SIZE] = {0};
 475         struct scrub_file_record **p = NULL;
 476
 477         if (fd < 0)
 478                 return ERR_PTR(-EINVAL);
 479
 480 again:
 481         old_avail = avail - i;
 482         BUG_ON(old_avail < 0);
 483         if (old_avail)
 484                 memmove(l, l + i, old_avail);
 485         avail = read(fd, l + old_avail, sizeof(l) - old_avail);
 486         if (avail == 0)
 487                 eof = 1;
 488         if (avail == 0 && old_avail == 0) {
 489                 if (curr >= 0 &&
 490                     memcmp(p[curr]->fsid, empty_uuid, BTRFS_FSID_SIZE) == 0) {
 491                         p[curr] = NULL;
 492                 } else if (curr == -1) {
 493                         p = ERR_PTR(-ENODATA);
 494                 }
 495                 return p;
 496         }
 497         if (avail == -1)
 498                 return ERR_PTR(-errno);
 499         avail += old_avail;
 500
 501         i = 0;
 502         while (i < avail) {
 503                 switch (state) {
 504                 case 0: /* start of file */
 505                         ret = scrub_kvread(&i,
 506                                 sizeof(SCRUB_FILE_VERSION_PREFIX), avail, l,
 507                                 SCRUB_FILE_VERSION_PREFIX, &version);
 508                         if (ret != 1)
 509                                 _SCRUB_INVALID;
 510                         if (version != atoll(SCRUB_FILE_VERSION))
 511                                 return ERR_PTR(-ENOTSUP);
 512                         state = 6;
 513                         continue;
 514                 case 1: /* start of line, alloc */
 515                         /*
 516                          * this state makes sure we have a complete line in
 517                          * further processing, so we don't need wrap-tracking
 518                          * everywhere.
 519                          */
 520                         if (!eof && !memchr(l + i, '\n', avail - i))
 521                                 goto again;
 522                         ++lineno;
 523                         if (curr > -1 && memcmp(p[curr]->fsid, empty_uuid,
 524                                                 BTRFS_FSID_SIZE) == 0) {
 525                                 state = 2;
 526                                 continue;
 527                         }
 528                         ++curr;
 529                         p = realloc(p, (curr + 2) * sizeof(*p));
 530                         if (p)
 531                                 p[curr] = malloc(sizeof(**p));
 532                         if (!p || !p[curr])
 533                                 return ERR_PTR(-errno);
 534                         memset(p[curr], 0, sizeof(**p));
 535                         p[curr + 1] = NULL;
 536                         ++state;
 537                         /* fall through */
 538                 case 2: /* start of line, skip space */
 539                         while (isspace(l[i]) && i < avail) {
 540                                 if (l[i] == '\n')
 541                                         ++lineno;
 542                                 ++i;
 543                         }
 544                         if (i >= avail ||
 545                             (!eof && !memchr(l + i, '\n', avail - i)))
 546                                 goto again;
 547                         ++state;
 548                         /* fall through */
 549                 case 3: /* read fsid */
 550                         if (i == avail)
 551                                 continue;
 552                         for (j = 0; l[i + j] != ':' && i + j < avail; ++j)
 553                                 ;
 554                         if (i + j + 1 >= avail)
 555                                 _SCRUB_INVALID;
 556                         if (j != 36)
 557                                 _SCRUB_INVALID;
 558                         l[i + j] = '\0';
 559                         ret = uuid_parse(l + i, p[curr]->fsid);
 560                         if (ret)
 561                                 _SCRUB_INVALID;
 562                         i += j + 1;
 563                         ++state;
 564                         /* fall through */
 565                 case 4: /* read dev id */
 566                         for (j = 0; isdigit(l[i + j]) && i+j < avail; ++j)
 567                                 ;
 568                         if (j == 0 || i + j + 1 >= avail)
 569                                 _SCRUB_INVALID;
 570                         p[curr]->devid = atoll(&l[i]);
 571                         i += j + 1;
 572                         ++state;
 573                         /* fall through */
 574                 case 5: /* read key/value pair */
 575                         ret = 0;
 576                         _SCRUB_KVREAD(ret, &i, data_extents_scrubbed, avail, l,
 577                                         &p[curr]->p);
 578                         _SCRUB_KVREAD(ret, &i, data_extents_scrubbed, avail, l,
 579                                         &p[curr]->p);
 580                         _SCRUB_KVREAD(ret, &i, tree_extents_scrubbed, avail, l,
 581                                         &p[curr]->p);
 582                         _SCRUB_KVREAD(ret, &i, data_bytes_scrubbed, avail, l,
 583                                         &p[curr]->p);
 584                         _SCRUB_KVREAD(ret, &i, tree_bytes_scrubbed, avail, l,
 585                                         &p[curr]->p);
 586                         _SCRUB_KVREAD(ret, &i, read_errors, avail, l,
 587                                         &p[curr]->p);
 588                         _SCRUB_KVREAD(ret, &i, csum_errors, avail, l,
 589                                         &p[curr]->p);
 590                         _SCRUB_KVREAD(ret, &i, verify_errors, avail, l,
 591                                         &p[curr]->p);
 592                         _SCRUB_KVREAD(ret, &i, no_csum, avail, l,
 593                                         &p[curr]->p);
 594                         _SCRUB_KVREAD(ret, &i, csum_discards, avail, l,
 595                                         &p[curr]->p);
 596                         _SCRUB_KVREAD(ret, &i, super_errors, avail, l,
 597                                         &p[curr]->p);
 598                         _SCRUB_KVREAD(ret, &i, malloc_errors, avail, l,
 599                                         &p[curr]->p);
 600                         _SCRUB_KVREAD(ret, &i, uncorrectable_errors, avail, l,
 601                                         &p[curr]->p);
 602                         _SCRUB_KVREAD(ret, &i, corrected_errors, avail, l,
 603                                         &p[curr]->p);
 604                         _SCRUB_KVREAD(ret, &i, last_physical, avail, l,
 605                                         &p[curr]->p);
 606                         _SCRUB_KVREAD(ret, &i, finished, avail, l,
 607                                         &p[curr]->stats);
 608                         _SCRUB_KVREAD(ret, &i, t_start, avail, l,
 609                                         (u64 *)&p[curr]->stats);
 610                         _SCRUB_KVREAD(ret, &i, t_resumed, avail, l,
 611                                         (u64 *)&p[curr]->stats);
 612                         _SCRUB_KVREAD(ret, &i, duration, avail, l,
 613                                         (u64 *)&p[curr]->stats);
 614                         _SCRUB_KVREAD(ret, &i, canceled, avail, l,
 615                                         &p[curr]->stats);
 616                         if (ret != 1)
 617                                 _SCRUB_INVALID;
 618                         ++state;
 619                         /* fall through */
 620                 case 6: /* after number */
 621                         if (l[i] == '|')
 622                                 state = 5;
 623                         else if (l[i] == '\n')
 624                                 state = 1;
 625                         else
 626                                 _SCRUB_INVALID;
 627                         ++i;
 628                         continue;
 629                 case 99: /* skip rest of line */
 630 skip:
 631                         state = 99;
 632                         do {
 633                                 ++i;
 634                                 if (l[i - 1] == '\n') {
 635                                         state = 1;
 636                                         break;
 637                                 }
 638                         } while (i < avail);
 639                         continue;
 640                 }
 641                 BUG();
 642         }
 643         goto again;
 644 }
 645
 646 static int scrub_write_buf(int fd, const void *data, int len)
 647 {
 648         int ret;
 649         ret = write(fd, data, len);
 650         return ret - len;
 651 }
 652
 653 static int scrub_writev(int fd, char *buf, int max, const char *fmt, ...)
 654                                 __attribute__ ((format (printf, 4, 5)));
 655 static int scrub_writev(int fd, char *buf, int max, const char *fmt, ...)
 656 {
 657         int ret;
 658         va_list args;
 659
 660         va_start(args, fmt);
 661         ret = vsnprintf(buf, max, fmt, args);
 662         va_end(args);
 663         if (ret >= max)
 664                 return ret - max;
 665         return scrub_write_buf(fd, buf, ret);
 666 }
 667
 668 #define _SCRUB_SUM(dest, data, name) dest->scrub_args.progress.name =   \
 669                         data->resumed->p.name + data->scrub_args.progress.name
 670
 671 static struct scrub_progress *scrub_resumed_stats(struct scrub_progress *data,
 672                                                   struct scrub_progress *dest)
 673 {
 674         if (!data->resumed || data->skip)
 675                 return data;
 676
 677         _SCRUB_SUM(dest, data, data_extents_scrubbed);
 678         _SCRUB_SUM(dest, data, tree_extents_scrubbed);
 679         _SCRUB_SUM(dest, data, data_bytes_scrubbed);
 680         _SCRUB_SUM(dest, data, tree_bytes_scrubbed);
 681         _SCRUB_SUM(dest, data, read_errors);
 682         _SCRUB_SUM(dest, data, csum_errors);
 683         _SCRUB_SUM(dest, data, verify_errors);
 684         _SCRUB_SUM(dest, data, no_csum);
 685         _SCRUB_SUM(dest, data, csum_discards);
 686         _SCRUB_SUM(dest, data, super_errors);
 687         _SCRUB_SUM(dest, data, malloc_errors);
 688         _SCRUB_SUM(dest, data, uncorrectable_errors);
 689         _SCRUB_SUM(dest, data, corrected_errors);
 690         _SCRUB_SUM(dest, data, last_physical);
 691         dest->stats.canceled = data->stats.canceled;
 692         dest->stats.finished = data->stats.finished;
 693         dest->stats.t_resumed = data->stats.t_start;
 694         dest->stats.t_start = data->resumed->stats.t_start;
 695         dest->stats.duration = data->resumed->stats.duration +
 696                                                         data->stats.duration;
 697         dest->scrub_args.devid = data->scrub_args.devid;
 698         return dest;
 699 }
 700
 701 #define _SCRUB_KVWRITE(fd, buf, name, use)              \
 702         scrub_kvwrite(fd, buf, sizeof(buf), #name,      \
 703                         use->scrub_args.progress.name)
 704
 705 #define _SCRUB_KVWRITE_STATS(fd, buf, name, use)        \
 706         scrub_kvwrite(fd, buf, sizeof(buf), #name,      \
 707                         use->stats.name)
 708
 709 static int scrub_kvwrite(int fd, char *buf, int max, const char *key, u64 val)
 710 {
 711         return scrub_writev(fd, buf, max, "|%s:%lld", key, val);
 712 }
 713
 714 static int scrub_write_file(int fd, const char *fsid,
 715                                 struct scrub_progress *data, int n)
 716 {
 717         int ret = 0;
 718         int i;
 719         char buf[1024];
 720         struct scrub_progress local;
 721         struct scrub_progress *use;
 722
 723         if (n < 1)
 724                 return -EINVAL;
 725
 726         /* each -1 is to subtract one \0 byte, the + 2 is for ':' and '\n' */
 727         ret = scrub_write_buf(fd, SCRUB_FILE_VERSION_PREFIX ":"
 728                                 SCRUB_FILE_VERSION "\n",
 729                                 (sizeof(SCRUB_FILE_VERSION_PREFIX) - 1) +
 730                                 (sizeof(SCRUB_FILE_VERSION) - 1) + 2);
 731         if (ret)
 732                 return -EOVERFLOW;
 733
 734         for (i = 0; i < n; ++i) {
 735                 use = scrub_resumed_stats(&data[i], &local);
 736                 if (scrub_write_buf(fd, fsid, strlen(fsid)) ||
 737                     scrub_write_buf(fd, ":", 1) ||
 738                     scrub_writev(fd, buf, sizeof(buf), "%lld",
 739                                         use->scrub_args.devid) ||
 740                     scrub_write_buf(fd, buf, ret) ||
 741                     _SCRUB_KVWRITE(fd, buf, data_extents_scrubbed, use) ||
 742                     _SCRUB_KVWRITE(fd, buf, tree_extents_scrubbed, use) ||
 743                     _SCRUB_KVWRITE(fd, buf, data_bytes_scrubbed, use) ||
 744                     _SCRUB_KVWRITE(fd, buf, tree_bytes_scrubbed, use) ||
 745                     _SCRUB_KVWRITE(fd, buf, read_errors, use) ||
 746                     _SCRUB_KVWRITE(fd, buf, csum_errors, use) ||
 747                     _SCRUB_KVWRITE(fd, buf, verify_errors, use) ||
 748                     _SCRUB_KVWRITE(fd, buf, no_csum, use) ||
 749                     _SCRUB_KVWRITE(fd, buf, csum_discards, use) ||
 750                     _SCRUB_KVWRITE(fd, buf, super_errors, use) ||
 751                     _SCRUB_KVWRITE(fd, buf, malloc_errors, use) ||
 752                     _SCRUB_KVWRITE(fd, buf, uncorrectable_errors, use) ||
 753                     _SCRUB_KVWRITE(fd, buf, corrected_errors, use) ||
 754                     _SCRUB_KVWRITE(fd, buf, last_physical, use) ||
 755                     _SCRUB_KVWRITE_STATS(fd, buf, t_start, use) ||
 756                     _SCRUB_KVWRITE_STATS(fd, buf, t_resumed, use) ||
 757                     _SCRUB_KVWRITE_STATS(fd, buf, duration, use) ||
 758                     _SCRUB_KVWRITE_STATS(fd, buf, canceled, use) ||
 759                     _SCRUB_KVWRITE_STATS(fd, buf, finished, use) ||
 760                     scrub_write_buf(fd, "\n", 1)) {
 761                         return -EOVERFLOW;
 762                 }
 763         }
 764
 765         return 0;
 766 }
 767
 768 static int scrub_write_progress(pthread_mutex_t *m, const char *fsid,
 769                                 struct scrub_progress *data, int n)
 770 {
 771         int ret;
 772         int err;
 773         int fd = -1;
 774         int old;
 775
 776         ret = pthread_mutex_lock(m);
 777         if (ret) {
 778                 err = -ret;
 779                 goto out;
 780         }
 781
 782         ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &old);
 783         if (ret) {
 784                 err = -ret;
 785                 goto out;
 786         }
 787
 788         fd = scrub_open_file_w(SCRUB_DATA_FILE, fsid, "tmp");
 789         if (fd < 0) {
 790                 err = fd;
 791                 goto out;
 792         }
 793         err = scrub_write_file(fd, fsid, data, n);
 794         if (err)
 795                 goto out;
 796         err = scrub_rename_file(SCRUB_DATA_FILE, fsid, "tmp");
 797         if (err)
 798                 goto out;
 799
 800 out:
 801         if (fd >= 0) {
 802                 ret = close(fd);
 803                 if (ret)
 804                         err = -errno;
 805         }
 806
 807         ret = pthread_mutex_unlock(m);
 808         if (ret && !err)
 809                 err = -ret;
 810
 811         ret = pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &old);
 812         if (ret && !err)
 813                 err = -ret;
 814
 815         return err;
 816 }
 817
 818 static void *scrub_one_dev(void *ctx)
 819 {
 820         struct scrub_progress *sp = ctx;
 821         int ret;
 822         struct timeval tv;
 823
 824         sp->stats.canceled = 0;
 825         sp->stats.duration = 0;
 826         sp->stats.finished = 0;
 827
 828         ret = syscall(SYS_ioprio_set, IOPRIO_WHO_PROCESS, 0,
 829                       IOPRIO_PRIO_VALUE(sp->ioprio_class,
 830                                         sp->ioprio_classdata));
 831         if (ret)
 832                 fprintf(stderr,
 833                         "WARNING: setting ioprio failed: %s (ignored).\n",
 834                         strerror(errno));
 835
 836         ret = ioctl(sp->fd, BTRFS_IOC_SCRUB, &sp->scrub_args);
 837         gettimeofday(&tv, NULL);
 838         sp->ret = ret;
 839         sp->stats.duration = tv.tv_sec - sp->stats.t_start;
 840         sp->stats.canceled = !!ret;
 841         sp->ioctl_errno = errno;
 842         ret = pthread_mutex_lock(&sp->progress_mutex);
 843         if (ret)
 844                 return ERR_PTR(-ret);
 845         sp->stats.finished = 1;
 846         ret = pthread_mutex_unlock(&sp->progress_mutex);
 847         if (ret)
 848                 return ERR_PTR(-ret);
 849
 850         return NULL;
 851 }
 852
 853 static void *progress_one_dev(void *ctx)
 854 {
 855         struct scrub_progress *sp = ctx;
 856
 857         sp->ret = ioctl(sp->fd, BTRFS_IOC_SCRUB_PROGRESS, &sp->scrub_args);
 858         sp->ioctl_errno = errno;
 859
 860         return NULL;
 861 }
 862
 863 /* nb: returns a negative errno via ERR_PTR */
 864 static void *scrub_progress_cycle(void *ctx)
 865 {
 866         int ret;
 867         int  perr = 0;  /* positive / pthread error returns */
 868         int old;
 869         int i;
 870         char fsid[BTRFS_UUID_UNPARSED_SIZE];
 871         struct scrub_progress *sp;
 872         struct scrub_progress *sp_last;
 873         struct scrub_progress *sp_shared;
 874         struct timeval tv;
 875         struct scrub_progress_cycle *spc = ctx;
 876         int ndev = spc->fi->num_devices;
 877         int this = 1;
 878         int last = 0;
 879         int peer_fd = -1;
 880         struct pollfd accept_poll_fd = {
 881                 .fd = spc->prg_fd,
 882                 .events = POLLIN,
 883                 .revents = 0,
 884         };
 885         struct pollfd write_poll_fd = {
 886                 .events = POLLOUT,
 887                 .revents = 0,
 888         };
 889         struct sockaddr_un peer;
 890         socklen_t peer_size = sizeof(peer);
 891
 892         perr = pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &old);
 893         if (perr)
 894                 goto out;
 895
 896         uuid_unparse(spc->fi->fsid, fsid);
 897
 898         for (i = 0; i < ndev; ++i) {
 899                 sp = &spc->progress[i];
 900                 sp_last = &spc->progress[i + ndev];
 901                 sp_shared = &spc->shared_progress[i];
 902                 sp->scrub_args.devid = sp_last->scrub_args.devid =
 903                                                 sp_shared->scrub_args.devid;
 904                 sp->fd = sp_last->fd = spc->fdmnt;
 905                 sp->stats.t_start = sp_last->stats.t_start =
 906                                                 sp_shared->stats.t_start;
 907                 sp->resumed = sp_last->resumed = sp_shared->resumed;
 908                 sp->skip = sp_last->skip = sp_shared->skip;
 909                 sp->stats.finished = sp_last->stats.finished =
 910                                                 sp_shared->stats.finished;
 911         }
 912
 913         while (1) {
 914                 ret = poll(&accept_poll_fd, 1, 5 * 1000);
 915                 if (ret == -1) {
 916                         ret = -errno;
 917                         goto out;
 918                 }
 919                 if (ret)
 920                         peer_fd = accept(spc->prg_fd, (struct sockaddr *)&peer,
 921                                          &peer_size);
 922                 gettimeofday(&tv, NULL);
 923                 this = (this + 1)%2;
 924                 last = (last + 1)%2;
 925                 for (i = 0; i < ndev; ++i) {
 926                         sp = &spc->progress[this * ndev + i];
 927                         sp_last = &spc->progress[last * ndev + i];
 928                         sp_shared = &spc->shared_progress[i];
 929                         if (sp->stats.finished)
 930                                 continue;
 931                         progress_one_dev(sp);
 932                         sp->stats.duration = tv.tv_sec - sp->stats.t_start;
 933                         if (!sp->ret)
 934                                 continue;
 935                         if (sp->ioctl_errno != ENOTCONN &&
 936                             sp->ioctl_errno != ENODEV) {
 937                                 ret = -sp->ioctl_errno;
 938                                 goto out;
 939                         }
 940                         /*
 941                          * scrub finished or device removed, check the
 942                          * finished flag. if unset, just use the last
 943                          * result we got for the current write and go
 944                          * on. flag should be set on next cycle, then.
 945                          */
 946                         perr = pthread_mutex_lock(&sp_shared->progress_mutex);
 947                         if (perr)
 948                                 goto out;
 949                         if (!sp_shared->stats.finished) {
 950                                 perr = pthread_mutex_unlock(
 951                                                 &sp_shared->progress_mutex);
 952                                 if (perr)
 953                                         goto out;
 954                                 memcpy(sp, sp_last, sizeof(*sp));
 955                                 continue;
 956                         }
 957                         perr = pthread_mutex_unlock(&sp_shared->progress_mutex);
 958                         if (perr)
 959                                 goto out;
 960                         memcpy(sp, sp_shared, sizeof(*sp));
 961                         memcpy(sp_last, sp_shared, sizeof(*sp));
 962                 }
 963                 if (peer_fd != -1) {
 964                         write_poll_fd.fd = peer_fd;
 965                         ret = poll(&write_poll_fd, 1, 0);
 966                         if (ret == -1) {
 967                                 ret = -errno;
 968                                 goto out;
 969                         }
 970                         if (ret) {
 971                                 ret = scrub_write_file(
 972                                         peer_fd, fsid,
 973                                         &spc->progress[this * ndev], ndev);
 974                                 if (ret)
 975                                         goto out;
 976                         }
 977                         close(peer_fd);
 978                         peer_fd = -1;
 979                 }
 980                 if (!spc->do_record)
 981                         continue;
 982                 ret = scrub_write_progress(spc->write_mutex, fsid,
 983                                            &spc->progress[this * ndev], ndev);
 984                 if (ret)
 985                         goto out;
 986         }
 987 out:
 988         if (peer_fd != -1)
 989                 close(peer_fd);
 990         if (perr)
 991                 ret = -perr;
 992         return ERR_PTR(ret);
 993 }
 994
 995 static struct scrub_file_record *last_dev_scrub(
 996                 struct scrub_file_record *const *const past_scrubs, u64 devid)
 997 {
 998         int i;
 999
1000         if (!past_scrubs || IS_ERR(past_scrubs))
1001                 return NULL;
1002
1003         for (i = 0; past_scrubs[i]; ++i)
1004                 if (past_scrubs[i]->devid == devid)
1005                         return past_scrubs[i];
1006
1007         return NULL;
1008 }
1009
1010 static int mkdir_p(char *path)
1011 {
1012         int i;
1013         int ret;
1014
1015         for (i = 1; i < strlen(path); ++i) {
1016                 if (path[i] != '/')
1017                         continue;
1018                 path[i] = '\0';
1019                 ret = mkdir(path, 0777);
1020                 if (ret && errno != EEXIST)
1021                         return -errno;
1022                 path[i] = '/';
1023         }
1024
1025         return 0;
1026 }
1027
1028 static int is_scrub_running_on_fs(struct btrfs_ioctl_fs_info_args *fi_args,
1029                                   struct btrfs_ioctl_dev_info_args *di_args,
1030                                   struct scrub_file_record **past_scrubs)
1031 {
1032         int i;
1033
1034         if (!fi_args || !di_args || !past_scrubs)
1035                 return 0;
1036
1037         for (i = 0; i < fi_args->num_devices; i++) {
1038                 struct scrub_file_record *sfr =
1039                         last_dev_scrub(past_scrubs, di_args[i].devid);
1040
1041                 if (!sfr)
1042                         continue;
1043                 if (!(sfr->stats.finished || sfr->stats.canceled))
1044                         return 1;
1045         }
1046         return 0;
1047 }
1048
1049 static const char * const cmd_scrub_start_usage[];
1050 static const char * const cmd_scrub_resume_usage[];
1051
1052 static int scrub_start(int argc, char **argv, int resume)
1053 {
1054         int fdmnt;
1055         int prg_fd = -1;
1056         int fdres = -1;
1057         int ret;
1058         pid_t pid;
1059         int c;
1060         int i;
1061         int err = 0;
1062         int e_uncorrectable = 0;
1063         int e_correctable = 0;
1064         int print_raw = 0;
1065         char *path;
1066         int do_background = 1;
1067         int do_wait = 0;
1068         int do_print = 0;
1069         int do_quiet = 0;
1070         int do_record = 1;
1071         int readonly = 0;
1072         int do_stats_per_dev = 0;
1073         int ioprio_class = IOPRIO_CLASS_IDLE;
1074         int ioprio_classdata = 0;
1075         int n_start = 0;
1076         int n_skip = 0;
1077         int n_resume = 0;
1078         struct btrfs_ioctl_fs_info_args fi_args;
1079         struct btrfs_ioctl_dev_info_args *di_args = NULL;
1080         struct scrub_progress *sp = NULL;
1081         struct scrub_fs_stat fs_stat;
1082         struct timeval tv;
1083         struct sockaddr_un addr = {
1084                 .sun_family = AF_UNIX,
1085         };
1086         pthread_t *t_devs = NULL;
1087         pthread_t t_prog;
1088         pthread_attr_t t_attr;
1089         struct scrub_file_record **past_scrubs = NULL;
1090         struct scrub_file_record *last_scrub = NULL;
1091         char *datafile = strdup(SCRUB_DATA_FILE);
1092         char fsid[BTRFS_UUID_UNPARSED_SIZE];
1093         char sock_path[BTRFS_PATH_NAME_MAX + 1] = "";
1094         struct scrub_progress_cycle spc;
1095         pthread_mutex_t spc_write_mutex = PTHREAD_MUTEX_INITIALIZER;
1096         void *terr;
1097         u64 devid;
1098         DIR *dirstream = NULL;
1099
1100         optind = 1;
1101         while ((c = getopt(argc, argv, "BdqrRc:n:")) != -1) {
1102                 switch (c) {
1103                 case 'B':
1104                         do_background = 0;
1105                         do_wait = 1;
1106                         do_print = 1;
1107                         break;
1108                 case 'd':
1109                         do_stats_per_dev = 1;
1110                         break;
1111                 case 'q':
1112                         do_quiet = 1;
1113                         break;
1114                 case 'r':
1115                         readonly = 1;
1116                         break;
1117                 case 'R':
1118                         print_raw = 1;
1119                         break;
1120                 case 'c':
1121                         ioprio_class = (int)strtol(optarg, NULL, 10);
1122                         break;
1123                 case 'n':
1124                         ioprio_classdata = (int)strtol(optarg, NULL, 10);
1125                         break;
1126                 case '?':
1127                 default:
1128                         usage(resume ? cmd_scrub_resume_usage :
1129                                                 cmd_scrub_start_usage);
1130                 }
1131         }
1132
1133         /* try to catch most error cases before forking */
1134
1135         if (check_argc_exact(argc - optind, 1)) {
1136                 usage(resume ? cmd_scrub_resume_usage :
1137                                         cmd_scrub_start_usage);
1138         }
1139
1140         spc.progress = NULL;
1141         if (do_quiet && do_print)
1142                 do_print = 0;
1143
1144         if (mkdir_p(datafile)) {
1145                 ERR(!do_quiet, "WARNING: cannot create scrub data "
1146                                "file, mkdir %s failed: %s. Status recording "
1147                                "disabled\n", datafile, strerror(errno));
1148                 do_record = 0;
1149         }
1150         free(datafile);
1151
1152         path = argv[optind];
1153
1154         fdmnt = open_path_or_dev_mnt(path, &dirstream);
1155
1156         if (fdmnt < 0) {
1157                 ERR(!do_quiet, "ERROR: can't access '%s'\n", path);
1158                 return 1;
1159         }
1160
1161         ret = get_fs_info(path, &fi_args, &di_args);
1162         if (ret) {
1163                 ERR(!do_quiet, "ERROR: getting dev info for scrub failed: "
1164                     "%s\n", strerror(-ret));
1165                 err = 1;
1166                 goto out;
1167         }
1168         if (!fi_args.num_devices) {
1169                 ERR(!do_quiet, "ERROR: no devices found\n");
1170                 err = 1;
1171                 goto out;
1172         }
1173
1174         uuid_unparse(fi_args.fsid, fsid);
1175         fdres = scrub_open_file_r(SCRUB_DATA_FILE, fsid);
1176         if (fdres < 0 && fdres != -ENOENT) {
1177                 ERR(!do_quiet, "WARNING: failed to open status file: "
1178                     "%s\n", strerror(-fdres));
1179         } else if (fdres >= 0) {
1180                 past_scrubs = scrub_read_file(fdres, !do_quiet);
1181                 if (IS_ERR(past_scrubs))
1182                         ERR(!do_quiet, "WARNING: failed to read status file: "
1183                             "%s\n", strerror(-PTR_ERR(past_scrubs)));
1184                 close(fdres);
1185         }
1186
1187         /*
1188          * check whether any involved device is already busy running a
1189          * scrub. This would cause damaged status messages and the state
1190          * "aborted" without the explanation that a scrub was already
1191          * running. Therefore check it first, prevent it and give some
1192          * feedback to the user if scrub is already running.
1193          * Note that if scrub is started with a block device as the
1194          * parameter, only that particular block device is checked. It
1195          * is a normal mode of operation to start scrub on multiple
1196          * single devices, there is no reason to prevent this.
1197          */
1198         if (is_scrub_running_on_fs(&fi_args, di_args, past_scrubs)) {
1199                 ERR(!do_quiet,
1200                     "ERROR: scrub is already running.\n"
1201                     "To cancel use 'btrfs scrub cancel %s'.\n"
1202                     "To see the status use 'btrfs scrub status [-d] %s'.\n",
1203                     path, path);
1204                 err = 1;
1205                 goto out;
1206         }
1207
1208         t_devs = malloc(fi_args.num_devices * sizeof(*t_devs));
1209         sp = calloc(fi_args.num_devices, sizeof(*sp));
1210         spc.progress = calloc(fi_args.num_devices * 2, sizeof(*spc.progress));
1211
1212         if (!t_devs || !sp || !spc.progress) {
1213                 ERR(!do_quiet, "ERROR: scrub failed: %s", strerror(errno));
1214                 err = 1;
1215                 goto out;
1216         }
1217
1218         ret = pthread_attr_init(&t_attr);
1219         if (ret) {
1220                 ERR(!do_quiet, "ERROR: pthread_attr_init failed: %s\n",
1221                     strerror(ret));
1222                 err = 1;
1223                 goto out;
1224         }
1225
1226         for (i = 0; i < fi_args.num_devices; ++i) {
1227                 devid = di_args[i].devid;
1228                 ret = pthread_mutex_init(&sp[i].progress_mutex, NULL);
1229                 if (ret) {
1230                         ERR(!do_quiet, "ERROR: pthread_mutex_init failed: "
1231                             "%s\n", strerror(ret));
1232                         err = 1;
1233                         goto out;
1234                 }
1235                 last_scrub = last_dev_scrub(past_scrubs, devid);
1236                 sp[i].scrub_args.devid = devid;
1237                 sp[i].fd = fdmnt;
1238                 if (resume && last_scrub && (last_scrub->stats.canceled ||
1239                                              !last_scrub->stats.finished)) {
1240                         ++n_resume;
1241                         sp[i].scrub_args.start = last_scrub->p.last_physical;
1242                         sp[i].resumed = last_scrub;
1243                 } else if (resume) {
1244                         ++n_skip;
1245                         sp[i].skip = 1;
1246                         sp[i].resumed = last_scrub;
1247                         continue;
1248                 } else {
1249                         ++n_start;
1250                         sp[i].scrub_args.start = 0ll;
1251                         sp[i].resumed = NULL;
1252                 }
1253                 sp[i].skip = 0;
1254                 sp[i].scrub_args.end = (u64)-1ll;
1255                 sp[i].scrub_args.flags = readonly ? BTRFS_SCRUB_READONLY : 0;
1256                 sp[i].ioprio_class = ioprio_class;
1257                 sp[i].ioprio_classdata = ioprio_classdata;
1258         }
1259
1260         if (!n_start && !n_resume) {
1261                 if (!do_quiet)
1262                         printf("scrub: nothing to resume for %s, fsid %s\n",
1263                                path, fsid);
1264                 return 2;
1265         }
1266
1267         ret = prg_fd = socket(AF_UNIX, SOCK_STREAM, 0);
1268         while (ret != -1) {
1269                 ret = scrub_datafile(SCRUB_PROGRESS_SOCKET_PATH, fsid, NULL,
1270                                         sock_path, sizeof(sock_path));
1271                 /* ignore EOVERFLOW, try using a shorter path for the socket */
1272                 addr.sun_path[sizeof(addr.sun_path) - 1] = '\0';
1273                 strncpy(addr.sun_path, sock_path, sizeof(addr.sun_path) - 1);
1274                 ret = bind(prg_fd, (struct sockaddr *)&addr, sizeof(addr));
1275                 if (ret != -1 || errno != EADDRINUSE)
1276                         break;
1277                 /*
1278                  * bind failed with EADDRINUSE. so let's see if anyone answers
1279                  * when we make a call to the socket ...
1280                  */
1281                 ret = connect(prg_fd, (struct sockaddr *)&addr, sizeof(addr));
1282                 if (!ret || errno != ECONNREFUSED) {
1283                         /* ... yes, so scrub must be running. error out */
1284                         fprintf(stderr, "ERROR: scrub already running\n");
1285                         close(prg_fd);
1286                         prg_fd = -1;
1287                         goto out;
1288                 }
1289                 /*
1290                  * ... no, this means someone left us alone with an unused
1291                  * socket in the file system. remove it and try again.
1292                  */
1293                 ret = unlink(sock_path);
1294         }
1295         if (ret != -1)
1296                 ret = listen(prg_fd, 100);
1297         if (ret == -1) {
1298                 ERR(!do_quiet, "WARNING: failed to open the progress status "
1299                     "socket at %s: %s. Progress cannot be queried\n",
1300                     sock_path[0] ? sock_path : SCRUB_PROGRESS_SOCKET_PATH,
1301                     strerror(errno));
1302                 if (prg_fd != -1) {
1303                         close(prg_fd);
1304                         prg_fd = -1;
1305                         if (sock_path[0])
1306                                 unlink(sock_path);
1307                 }
1308         }
1309
1310         if (do_record) {
1311                 /* write all-zero progress file for a start */
1312                 ret = scrub_write_progress(&spc_write_mutex, fsid, sp,
1313                                            fi_args.num_devices);
1314                 if (ret) {
1315                         ERR(!do_quiet, "WARNING: failed to write the progress "
1316                             "status file: %s. Status recording disabled\n",
1317                             strerror(-ret));
1318                         do_record = 0;
1319                 }
1320         }
1321
1322         if (do_background) {
1323                 pid = fork();
1324                 if (pid == -1) {
1325                         ERR(!do_quiet, "ERROR: cannot scrub, fork failed: "
1326                                         "%s\n", strerror(errno));
1327                         err = 1;
1328                         goto out;
1329                 }
1330
1331                 if (pid) {
1332                         int stat;
1333                         scrub_handle_sigint_parent();
1334                         if (!do_quiet)
1335                                 printf("scrub %s on %s, fsid %s (pid=%d)\n",
1336                                        n_start ? "started" : "resumed",
1337                                        path, fsid, pid);
1338                         if (!do_wait) {
1339                                 err = 0;
1340                                 goto out;
1341                         }
1342                         ret = wait(&stat);
1343                         if (ret != pid) {
1344                                 ERR(!do_quiet, "ERROR: wait failed: (ret=%d) "
1345                                     "%s\n", ret, strerror(errno));
1346                                 err = 1;
1347                                 goto out;
1348                         }
1349                         if (!WIFEXITED(stat) || WEXITSTATUS(stat)) {
1350                                 ERR(!do_quiet, "ERROR: scrub process failed\n");
1351                                 err = WIFEXITED(stat) ? WEXITSTATUS(stat) : -1;
1352                                 goto out;
1353                         }
1354                         err = 0;
1355                         goto out;
1356                 }
1357         }
1358
1359         scrub_handle_sigint_child(fdmnt);
1360
1361         for (i = 0; i < fi_args.num_devices; ++i) {
1362                 if (sp[i].skip) {
1363                         sp[i].scrub_args.progress = sp[i].resumed->p;
1364                         sp[i].stats = sp[i].resumed->stats;
1365                         sp[i].ret = 0;
1366                         sp[i].stats.finished = 1;
1367                         continue;
1368                 }
1369                 devid = di_args[i].devid;
1370                 gettimeofday(&tv, NULL);
1371                 sp[i].stats.t_start = tv.tv_sec;
1372                 ret = pthread_create(&t_devs[i], &t_attr,
1373                                         scrub_one_dev, &sp[i]);
1374                 if (ret) {
1375                         if (do_print)
1376                                 fprintf(stderr, "ERROR: creating "
1377                                         "scrub_one_dev[%llu] thread failed: "
1378                                         "%s\n", devid, strerror(ret));
1379                         err = 1;
1380                         goto out;
1381                 }
1382         }
1383
1384         spc.fdmnt = fdmnt;
1385         spc.prg_fd = prg_fd;
1386         spc.do_record = do_record;
1387         spc.write_mutex = &spc_write_mutex;
1388         spc.shared_progress = sp;
1389         spc.fi = &fi_args;
1390         ret = pthread_create(&t_prog, &t_attr, scrub_progress_cycle, &spc);
1391         if (ret) {
1392                 if (do_print)
1393                         fprintf(stderr, "ERROR: creating progress thread "
1394                                 "failed: %s\n", strerror(ret));
1395                 err = 1;
1396                 goto out;
1397         }
1398
1399         err = 0;
1400         for (i = 0; i < fi_args.num_devices; ++i) {
1401                 if (sp[i].skip)
1402                         continue;
1403                 devid = di_args[i].devid;
1404                 ret = pthread_join(t_devs[i], NULL);
1405                 if (ret) {
1406                         if (do_print)
1407                                 fprintf(stderr, "ERROR: pthread_join failed "
1408                                         "for scrub_one_dev[%llu]: %s\n", devid,
1409                                         strerror(ret));
1410                         ++err;
1411                         continue;
1412                 }
1413                 if (sp[i].ret && sp[i].ioctl_errno == ENODEV) {
1414                         if (do_print)
1415                                 fprintf(stderr, "WARNING: device %lld not "
1416                                         "present\n", devid);
1417                         continue;
1418                 }
1419                 if (sp[i].ret && sp[i].ioctl_errno == ECANCELED) {
1420                         ++err;
1421                 } else if (sp[i].ret) {
1422                         if (do_print)
1423                                 fprintf(stderr, "ERROR: scrubbing %s failed "
1424                                         "for device id %lld (%s)\n", path,
1425                                         devid, strerror(sp[i].ioctl_errno));
1426                         ++err;
1427                         continue;
1428                 }
1429                 if (sp[i].scrub_args.progress.uncorrectable_errors > 0)
1430                         e_uncorrectable++;
1431                 if (sp[i].scrub_args.progress.corrected_errors > 0
1432                     || sp[i].scrub_args.progress.unverified_errors > 0)
1433                         e_correctable++;
1434         }
1435
1436         if (do_print) {
1437                 const char *append = "done";
1438                 if (!do_stats_per_dev)
1439                         init_fs_stat(&fs_stat);
1440                 for (i = 0; i < fi_args.num_devices; ++i) {
1441                         if (do_stats_per_dev) {
1442                                 print_scrub_dev(&di_args[i],
1443                                                 &sp[i].scrub_args.progress,
1444                                                 print_raw,
1445                                                 sp[i].ret ? "canceled" : "done",
1446                                                 &sp[i].stats);
1447                         } else {
1448                                 if (sp[i].ret)
1449                                         append = "canceled";
1450                                 add_to_fs_stat(&sp[i].scrub_args.progress,
1451                                                 &sp[i].stats, &fs_stat);
1452                         }
1453                 }
1454                 if (!do_stats_per_dev) {
1455                         printf("scrub %s for %s\n", append, fsid);
1456                         print_fs_stat(&fs_stat, print_raw);
1457                 }
1458         }
1459
1460         ret = pthread_cancel(t_prog);
1461         if (!ret)
1462                 ret = pthread_join(t_prog, &terr);
1463
1464         /* check for errors from the handling of the progress thread */
1465         if (do_print && ret) {
1466                 fprintf(stderr, "ERROR: progress thread handling failed: %s\n",
1467                         strerror(ret));
1468         }
1469
1470         /* check for errors returned from the progress thread itself */
1471         if (do_print && terr && terr != PTHREAD_CANCELED) {
1472                 fprintf(stderr, "ERROR: recording progress "
1473                         "failed: %s\n", strerror(-PTR_ERR(terr)));
1474         }
1475
1476         if (do_record) {
1477                 ret = scrub_write_progress(&spc_write_mutex, fsid, sp,
1478                                            fi_args.num_devices);
1479                 if (ret && do_print) {
1480                         fprintf(stderr, "ERROR: failed to record the result: "
1481                                 "%s\n", strerror(-ret));
1482                 }
1483         }
1484
1485         scrub_handle_sigint_child(-1);
1486
1487 out:
1488         free_history(past_scrubs);
1489         free(di_args);
1490         free(t_devs);
1491         free(sp);
1492         free(spc.progress);
1493         if (prg_fd > -1) {
1494                 close(prg_fd);
1495                 if (sock_path[0])
1496                         unlink(sock_path);
1497         }
1498         close_file_or_dir(fdmnt, dirstream);
1499
1500         if (err)
1501                 return 1;
1502         if (e_correctable)
1503                 return 3;
1504         if (e_uncorrectable)
1505                 return 4;
1506         return 0;
1507 }
1508
1509 static const char * const cmd_scrub_start_usage[] = {
1510         "btrfs scrub start [-BdqrR] [-c ioprio_class -n ioprio_classdata] <path>|<device>",
1511         "Start a new scrub",
1512         "",
1513         "-B     do not background",
1514         "-d     stats per device (-B only)",
1515         "-q     be quiet",
1516         "-r     read only mode",
1517         "-R     raw print mode, print full data instead of summary"
1518         "-c     set ioprio class (see ionice(1) manpage)",
1519         "-n     set ioprio classdata (see ionice(1) manpage)",
1520         NULL
1521 };
1522
1523 static int cmd_scrub_start(int argc, char **argv)
1524 {
1525         return scrub_start(argc, argv, 0);
1526 }
1527
1528 static const char * const cmd_scrub_cancel_usage[] = {
1529         "btrfs scrub cancel <path>|<device>",
1530         "Cancel a running scrub",
1531         NULL
1532 };
1533
1534 static int cmd_scrub_cancel(int argc, char **argv)
1535 {
1536         char *path;
1537         int ret;
1538         int fdmnt = -1;
1539         DIR *dirstream = NULL;
1540
1541         if (check_argc_exact(argc, 2))
1542                 usage(cmd_scrub_cancel_usage);
1543
1544         path = argv[1];
1545
1546         fdmnt = open_path_or_dev_mnt(path, &dirstream);
1547         if (fdmnt < 0) {
1548                 fprintf(stderr, "ERROR: could not open %s: %s\n",
1549                         path, strerror(errno));
1550                 ret = 1;
1551                 goto out;
1552         }
1553
1554         ret = ioctl(fdmnt, BTRFS_IOC_SCRUB_CANCEL, NULL);
1555
1556         if (ret < 0) {
1557                 fprintf(stderr, "ERROR: scrub cancel failed on %s: %s\n", path,
1558                         errno == ENOTCONN ? "not running" : strerror(errno));
1559                 if (errno == ENOTCONN)
1560                         ret = 2;
1561                 else
1562                         ret = 1;
1563                 goto out;
1564         }
1565
1566         ret = 0;
1567         printf("scrub cancelled\n");
1568
1569 out:
1570         close_file_or_dir(fdmnt, dirstream);
1571         return ret;
1572 }
1573
1574 static const char * const cmd_scrub_resume_usage[] = {
1575         "btrfs scrub resume [-BdqrR] [-c ioprio_class -n ioprio_classdata] <path>|<device>",
1576         "Resume previously canceled or interrupted scrub",
1577         "",
1578         "-B     do not background",
1579         "-d     stats per device (-B only)",
1580         "-q     be quiet",
1581         "-r     read only mode",
1582         "-c     set ioprio class (see ionice(1) manpage)",
1583         "-n     set ioprio classdata (see ionice(1) manpage)",
1584         NULL
1585 };
1586
1587 static int cmd_scrub_resume(int argc, char **argv)
1588 {
1589         return scrub_start(argc, argv, 1);
1590 }
1591
1592 static const char * const cmd_scrub_status_usage[] = {
1593         "btrfs scrub status [-dR] <path>|<device>",
1594         "Show status of running or finished scrub",
1595         "",
1596         "-d     stats per device",
1597         "-R     print raw stats",
1598         NULL
1599 };
1600
1601 static int cmd_scrub_status(int argc, char **argv)
1602 {
1603         char *path;
1604         struct btrfs_ioctl_fs_info_args fi_args;
1605         struct btrfs_ioctl_dev_info_args *di_args = NULL;
1606         struct scrub_file_record **past_scrubs = NULL;
1607         struct scrub_file_record *last_scrub;
1608         struct scrub_fs_stat fs_stat;
1609         struct sockaddr_un addr = {
1610                 .sun_family = AF_UNIX,
1611         };
1612         int ret;
1613         int i;
1614         int fdmnt;
1615         int print_raw = 0;
1616         int do_stats_per_dev = 0;
1617         int c;
1618         char fsid[BTRFS_UUID_UNPARSED_SIZE];
1619         int fdres = -1;
1620         int err = 0;
1621         DIR *dirstream = NULL;
1622
1623         optind = 1;
1624         while ((c = getopt(argc, argv, "dR")) != -1) {
1625                 switch (c) {
1626                 case 'd':
1627                         do_stats_per_dev = 1;
1628                         break;
1629                 case 'R':
1630                         print_raw = 1;
1631                         break;
1632                 case '?':
1633                 default:
1634                         usage(cmd_scrub_status_usage);
1635                 }
1636         }
1637
1638         if (check_argc_exact(argc - optind, 1))
1639                 usage(cmd_scrub_status_usage);
1640
1641         path = argv[optind];
1642
1643         fdmnt = open_path_or_dev_mnt(path, &dirstream);
1644
1645         if (fdmnt < 0) {
1646                 fprintf(stderr, "ERROR: can't access to '%s'\n", path);
1647                 return 1;
1648         }
1649
1650         ret = get_fs_info(path, &fi_args, &di_args);
1651         if (ret) {
1652                 fprintf(stderr, "ERROR: getting dev info for scrub failed: "
1653                                 "%s\n", strerror(-ret));
1654                 err = 1;
1655                 goto out;
1656         }
1657         if (!fi_args.num_devices) {
1658                 fprintf(stderr, "ERROR: no devices found\n");
1659                 err = 1;
1660                 goto out;
1661         }
1662
1663         uuid_unparse(fi_args.fsid, fsid);
1664
1665         fdres = socket(AF_UNIX, SOCK_STREAM, 0);
1666         if (fdres == -1) {
1667                 fprintf(stderr, "ERROR: failed to create socket to "
1668                         "receive progress information: %s\n",
1669                         strerror(errno));
1670                 err = 1;
1671                 goto out;
1672         }
1673         scrub_datafile(SCRUB_PROGRESS_SOCKET_PATH, fsid,
1674                         NULL, addr.sun_path, sizeof(addr.sun_path));
1675         /* ignore EOVERFLOW, just use shorter name and hope for the best */
1676         addr.sun_path[sizeof(addr.sun_path) - 1] = '\0';
1677         ret = connect(fdres, (struct sockaddr *)&addr, sizeof(addr));
1678         if (ret == -1) {
1679                 close(fdres);
1680                 fdres = scrub_open_file_r(SCRUB_DATA_FILE, fsid);
1681                 if (fdres < 0 && fdres != -ENOENT) {
1682                         fprintf(stderr, "WARNING: failed to open status file: "
1683                                 "%s\n", strerror(-fdres));
1684                         err = 1;
1685                         goto out;
1686                 }
1687         }
1688
1689         if (fdres >= 0) {
1690                 past_scrubs = scrub_read_file(fdres, 1);
1691                 if (IS_ERR(past_scrubs))
1692                         fprintf(stderr, "WARNING: failed to read status: %s\n",
1693                                 strerror(-PTR_ERR(past_scrubs)));
1694         }
1695
1696         printf("scrub status for %s\n", fsid);
1697
1698         if (do_stats_per_dev) {
1699                 for (i = 0; i < fi_args.num_devices; ++i) {
1700                         last_scrub = last_dev_scrub(past_scrubs,
1701                                                         di_args[i].devid);
1702                         if (!last_scrub) {
1703                                 print_scrub_dev(&di_args[i], NULL, print_raw,
1704                                                 NULL, NULL);
1705                                 continue;
1706                         }
1707                         print_scrub_dev(&di_args[i], &last_scrub->p, print_raw,
1708                                         last_scrub->stats.finished ?
1709                                                         "history" : "status",
1710                                         &last_scrub->stats);
1711                 }
1712         } else {
1713                 init_fs_stat(&fs_stat);
1714                 for (i = 0; i < fi_args.num_devices; ++i) {
1715                         last_scrub = last_dev_scrub(past_scrubs,
1716                                                         di_args[i].devid);
1717                         if (!last_scrub)
1718                                 continue;
1719                         add_to_fs_stat(&last_scrub->p, &last_scrub->stats,
1720                                         &fs_stat);
1721                 }
1722                 print_fs_stat(&fs_stat, print_raw);
1723         }
1724
1725 out:
1726         free_history(past_scrubs);
1727         free(di_args);
1728         if (fdres > -1)
1729                 close(fdres);
1730         close_file_or_dir(fdmnt, dirstream);
1731
1732         return !!err;
1733 }
1734
1735 const struct cmd_group scrub_cmd_group = {
1736         scrub_cmd_group_usage, NULL, {
1737                 { "start", cmd_scrub_start, cmd_scrub_start_usage, NULL, 0 },
1738                 { "cancel", cmd_scrub_cancel, cmd_scrub_cancel_usage, NULL, 0 },
1739                 { "resume", cmd_scrub_resume, cmd_scrub_resume_usage, NULL, 0 },
1740                 { "status", cmd_scrub_status, cmd_scrub_status_usage, NULL, 0 },
1741                 NULL_CMD_STRUCT
1742         }
1743 };
1744
1745 int cmd_scrub(int argc, char **argv)
1746 {
1747         return handle_command_group(&scrub_cmd_group, argc, argv);
1748 }