cmds-balance.c

   1 /*
   2  * This program is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU General Public
   4  * License v2 as published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   9  * General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public
  12  * License along with this program; if not, write to the
  13  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  14  * Boston, MA 021110-1307, USA.
  15  */
  16
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <unistd.h>
  21 #include <getopt.h>
  22 #include <sys/ioctl.h>
  23 #include <errno.h>
  24
  25 #include "kerncompat.h"
  26 #include "ctree.h"
  27 #include "ioctl.h"
  28 #include "volumes.h"
  29
  30 #include "commands.h"
  31 #include "utils.h"
  32
  33 static const char * const balance_cmd_group_usage[] = {
  34         "btrfs balance <command> [options] <path>",
  35         "btrfs balance <path>",
  36         NULL
  37 };
  38
  39 static int parse_one_profile(const char *profile, u64 *flags)
  40 {
  41         if (!strcmp(profile, "raid0")) {
  42                 *flags |= BTRFS_BLOCK_GROUP_RAID0;
  43         } else if (!strcmp(profile, "raid1")) {
  44                 *flags |= BTRFS_BLOCK_GROUP_RAID1;
  45         } else if (!strcmp(profile, "raid10")) {
  46                 *flags |= BTRFS_BLOCK_GROUP_RAID10;
  47         } else if (!strcmp(profile, "raid5")) {
  48                 *flags |= BTRFS_BLOCK_GROUP_RAID5;
  49         } else if (!strcmp(profile, "raid6")) {
  50                 *flags |= BTRFS_BLOCK_GROUP_RAID6;
  51         } else if (!strcmp(profile, "dup")) {
  52                 *flags |= BTRFS_BLOCK_GROUP_DUP;
  53         } else if (!strcmp(profile, "single")) {
  54                 *flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE;
  55         } else {
  56                 error("unknown profile: %s", profile);
  57                 return 1;
  58         }
  59
  60         return 0;
  61 }
  62
  63 static int parse_profiles(char *profiles, u64 *flags)
  64 {
  65         char *this_char;
  66         char *save_ptr = NULL; /* Satisfy static checkers */
  67
  68         for (this_char = strtok_r(profiles, "|", &save_ptr);
  69              this_char != NULL;
  70              this_char = strtok_r(NULL, "|", &save_ptr)) {
  71                 if (parse_one_profile(this_char, flags))
  72                         return 1;
  73         }
  74
  75         return 0;
  76 }
  77
  78 static int parse_u64(const char *str, u64 *result)
  79 {
  80         char *endptr;
  81         u64 val;
  82
  83         val = strtoull(str, &endptr, 10);
  84         if (*endptr)
  85                 return 1;
  86
  87         *result = val;
  88         return 0;
  89 }
  90
  91 /*
  92  * Parse range that's missing some part that can be implicit:
  93  * a..b - exact range, a can be equal to b
  94  * a..  - implicitly unbounded maximum (end == (u64)-1)
  95  * ..b  - implicitly starting at 0
  96  * a    - invalid; unclear semantics, use parse_u64 instead
  97  *
  98  * Returned values are u64, value validation and interpretation should be done
  99  * by the caller.
 100  */
 101 static int parse_range(const char *range, u64 *start, u64 *end)
 102 {
 103         char *dots;
 104         char *endptr;
 105         const char *rest;
 106         int skipped = 0;
 107
 108         dots = strstr(range, "..");
 109         if (!dots)
 110                 return 1;
 111
 112         rest = dots + 2;
 113
 114         if (!*rest) {
 115                 *end = (u64)-1;
 116                 skipped++;
 117         } else {
 118                 *end = strtoull(rest, &endptr, 10);
 119                 if (*endptr)
 120                         return 1;
 121         }
 122         if (dots == range) {
 123                 *start = 0;
 124                 skipped++;
 125         } else {
 126                 *start = strtoull(range, &endptr, 10);
 127                 if (*endptr != 0 && *endptr != '.')
 128                         return 1;
 129         }
 130
 131         if (*start > *end) {
 132                 error("range %llu..%llu doesn't make sense",
 133                         (unsigned long long)*start,
 134                         (unsigned long long)*end);
 135                 return 1;
 136         }
 137
 138         if (skipped <= 1)
 139                 return 0;
 140
 141         return 1;
 142 }
 143
 144 /*
 145  * Parse range and check if start < end
 146  */
 147 static int parse_range_strict(const char *range, u64 *start, u64 *end)
 148 {
 149         if (parse_range(range, start, end) == 0) {
 150                 if (*start >= *end) {
 151                         error("range %llu..%llu not allowed",
 152                                 (unsigned long long)*start,
 153                                 (unsigned long long)*end);
 154                         return 1;
 155                 }
 156                 return 0;
 157         }
 158
 159         return 1;
 160 }
 161
 162 /*
 163  * Convert 64bit range to 32bit with boundary checks
 164  */
 165 static int range_to_u32(u64 start, u64 end, u32 *start32, u32 *end32)
 166 {
 167         if (start > (u32)-1)
 168                 return 1;
 169
 170         if (end != (u64)-1 && end > (u32)-1)
 171                 return 1;
 172
 173         *start32 = (u32)start;
 174         *end32 = (u32)end;
 175
 176         return 0;
 177 }
 178
 179 __attribute__ ((unused))
 180 static int parse_range_u32(const char *range, u32 *start, u32 *end)
 181 {
 182         u64 tmp_start;
 183         u64 tmp_end;
 184
 185         if (parse_range(range, &tmp_start, &tmp_end))
 186                 return 1;
 187
 188         if (range_to_u32(tmp_start, tmp_end, start, end))
 189                 return 1;
 190
 191         return 0;
 192 }
 193
 194 __attribute__ ((unused))
 195 static void print_range(u64 start, u64 end)
 196 {
 197         if (start)
 198                 printf("%llu", (unsigned long long)start);
 199         printf("..");
 200         if (end != (u64)-1)
 201                 printf("%llu", (unsigned long long)end);
 202 }
 203
 204 __attribute__ ((unused))
 205 static void print_range_u32(u32 start, u32 end)
 206 {
 207         if (start)
 208                 printf("%u", start);
 209         printf("..");
 210         if (end != (u32)-1)
 211                 printf("%u", end);
 212 }
 213
 214 static int parse_filters(char *filters, struct btrfs_balance_args *args)
 215 {
 216         char *this_char;
 217         char *value;
 218         char *save_ptr = NULL; /* Satisfy static checkers */
 219
 220         if (!filters)
 221                 return 0;
 222
 223         for (this_char = strtok_r(filters, ",", &save_ptr);
 224              this_char != NULL;
 225              this_char = strtok_r(NULL, ",", &save_ptr)) {
 226                 if ((value = strchr(this_char, '=')) != NULL)
 227                         *value++ = 0;
 228                 if (!strcmp(this_char, "profiles")) {
 229                         if (!value || !*value) {
 230                                 error("the profiles filter requires an argument");
 231                                 return 1;
 232                         }
 233                         if (parse_profiles(value, &args->profiles)) {
 234                                 error("invalid profiles argument");
 235                                 return 1;
 236                         }
 237                         args->flags |= BTRFS_BALANCE_ARGS_PROFILES;
 238                 } else if (!strcmp(this_char, "usage")) {
 239                         if (!value || !*value) {
 240                                 error("the usage filter requires an argument");
 241                                 return 1;
 242                         }
 243                         if (parse_u64(value, &args->usage)) {
 244                                 if (parse_range_u32(value, &args->usage_min,
 245                                                         &args->usage_max)) {
 246                                         error("invalid usage argument: %s",
 247                                                 value);
 248                                         return 1;
 249                                 }
 250                                 if (args->usage_max > 100) {
 251                                         error("invalid usage argument: %s",
 252                                                 value);
 253                                 }
 254                                 args->flags &= ~BTRFS_BALANCE_ARGS_USAGE;
 255                                 args->flags |= BTRFS_BALANCE_ARGS_USAGE_RANGE;
 256                         } else {
 257                                 if (args->usage > 100) {
 258                                         error("invalid usage argument: %s",
 259                                                 value);
 260                                         return 1;
 261                                 }
 262                                 args->flags &= ~BTRFS_BALANCE_ARGS_USAGE_RANGE;
 263                                 args->flags |= BTRFS_BALANCE_ARGS_USAGE;
 264                         }
 265                         args->flags |= BTRFS_BALANCE_ARGS_USAGE;
 266                 } else if (!strcmp(this_char, "devid")) {
 267                         if (!value || !*value) {
 268                                 error("the devid filter requires an argument");
 269                                 return 1;
 270                         }
 271                         if (parse_u64(value, &args->devid) || args->devid == 0) {
 272                                 error("invalid devid argument: %s", value);
 273                                 return 1;
 274                         }
 275                         args->flags |= BTRFS_BALANCE_ARGS_DEVID;
 276                 } else if (!strcmp(this_char, "drange")) {
 277                         if (!value || !*value) {
 278                                 error("the drange filter requires an argument");
 279                                 return 1;
 280                         }
 281                         if (parse_range_strict(value, &args->pstart, &args->pend)) {
 282                                 error("invalid drange argument");
 283                                 return 1;
 284                         }
 285                         args->flags |= BTRFS_BALANCE_ARGS_DRANGE;
 286                 } else if (!strcmp(this_char, "vrange")) {
 287                         if (!value || !*value) {
 288                                 error("the vrange filter requires an argument");
 289                                 return 1;
 290                         }
 291                         if (parse_range_strict(value, &args->vstart, &args->vend)) {
 292                                 error("invalid vrange argument");
 293                                 return 1;
 294                         }
 295                         args->flags |= BTRFS_BALANCE_ARGS_VRANGE;
 296                 } else if (!strcmp(this_char, "convert")) {
 297                         if (!value || !*value) {
 298                                 error("the convert option requires an argument");
 299                                 return 1;
 300                         }
 301                         if (parse_one_profile(value, &args->target)) {
 302                                 error("invalid convert argument");
 303                                 return 1;
 304                         }
 305                         args->flags |= BTRFS_BALANCE_ARGS_CONVERT;
 306                 } else if (!strcmp(this_char, "soft")) {
 307                         args->flags |= BTRFS_BALANCE_ARGS_SOFT;
 308                 } else if (!strcmp(this_char, "limit")) {
 309                         if (!value || !*value) {
 310                                 error("the limit filter requires an argument");
 311                                 return 1;
 312                         }
 313                         if (parse_u64(value, &args->limit)) {
 314                                 if (parse_range_u32(value, &args->limit_min,
 315                                                         &args->limit_max)) {
 316                                         error("Invalid limit argument: %s",
 317                                                value);
 318                                         return 1;
 319                                 }
 320                                 args->flags &= ~BTRFS_BALANCE_ARGS_LIMIT;
 321                                 args->flags |= BTRFS_BALANCE_ARGS_LIMIT_RANGE;
 322                         } else {
 323                                 args->flags &= ~BTRFS_BALANCE_ARGS_LIMIT_RANGE;
 324                                 args->flags |= BTRFS_BALANCE_ARGS_LIMIT;
 325                         }
 326                 } else if (!strcmp(this_char, "stripes")) {
 327                         if (!value || !*value) {
 328                                 error("the stripes filter requires an argument");
 329                                 return 1;
 330                         }
 331                         if (parse_range_u32(value, &args->stripes_min,
 332                                             &args->stripes_max)) {
 333                                 error("invalid stripes argument");
 334                                 return 1;
 335                         }
 336                         args->flags |= BTRFS_BALANCE_ARGS_STRIPES_RANGE;
 337                 } else {
 338                         error("unrecognized balance option: %s", this_char);
 339                         return 1;
 340                 }
 341         }
 342
 343         return 0;
 344 }
 345
 346 static void dump_balance_args(struct btrfs_balance_args *args)
 347 {
 348         if (args->flags & BTRFS_BALANCE_ARGS_CONVERT) {
 349                 printf("converting, target=%llu, soft is %s",
 350                        (unsigned long long)args->target,
 351                        (args->flags & BTRFS_BALANCE_ARGS_SOFT) ? "on" : "off");
 352         } else {
 353                 printf("balancing");
 354         }
 355
 356         if (args->flags & BTRFS_BALANCE_ARGS_PROFILES)
 357                 printf(", profiles=%llu", (unsigned long long)args->profiles);
 358         if (args->flags & BTRFS_BALANCE_ARGS_USAGE)
 359                 printf(", usage=%llu", (unsigned long long)args->usage);
 360         if (args->flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) {
 361                 printf(", usage=");
 362                 print_range_u32(args->usage_min, args->usage_max);
 363         }
 364         if (args->flags & BTRFS_BALANCE_ARGS_DEVID)
 365                 printf(", devid=%llu", (unsigned long long)args->devid);
 366         if (args->flags & BTRFS_BALANCE_ARGS_DRANGE)
 367                 printf(", drange=%llu..%llu",
 368                        (unsigned long long)args->pstart,
 369                        (unsigned long long)args->pend);
 370         if (args->flags & BTRFS_BALANCE_ARGS_VRANGE)
 371                 printf(", vrange=%llu..%llu",
 372                        (unsigned long long)args->vstart,
 373                        (unsigned long long)args->vend);
 374         if (args->flags & BTRFS_BALANCE_ARGS_LIMIT)
 375                 printf(", limit=%llu", (unsigned long long)args->limit);
 376         if (args->flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE) {
 377                 printf(", limit=");
 378                 print_range_u32(args->limit_min, args->limit_max);
 379         }
 380         if (args->flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE) {
 381                 printf(", stripes=");
 382                 print_range_u32(args->stripes_min, args->stripes_max);
 383         }
 384
 385         printf("\n");
 386 }
 387
 388 static void dump_ioctl_balance_args(struct btrfs_ioctl_balance_args *args)
 389 {
 390         printf("Dumping filters: flags 0x%llx, state 0x%llx, force is %s\n",
 391                (unsigned long long)args->flags, (unsigned long long)args->state,
 392                (args->flags & BTRFS_BALANCE_FORCE) ? "on" : "off");
 393         if (args->flags & BTRFS_BALANCE_DATA) {
 394                 printf("  DATA (flags 0x%llx): ",
 395                        (unsigned long long)args->data.flags);
 396                 dump_balance_args(&args->data);
 397         }
 398         if (args->flags & BTRFS_BALANCE_METADATA) {
 399                 printf("  METADATA (flags 0x%llx): ",
 400                        (unsigned long long)args->meta.flags);
 401                 dump_balance_args(&args->meta);
 402         }
 403         if (args->flags & BTRFS_BALANCE_SYSTEM) {
 404                 printf("  SYSTEM (flags 0x%llx): ",
 405                        (unsigned long long)args->sys.flags);
 406                 dump_balance_args(&args->sys);
 407         }
 408 }
 409
 410 static int do_balance_v1(int fd)
 411 {
 412         struct btrfs_ioctl_vol_args args;
 413         int ret;
 414
 415         memset(&args, 0, sizeof(args));
 416         ret = ioctl(fd, BTRFS_IOC_BALANCE, &args);
 417         return ret;
 418 }
 419
 420 enum {
 421         BALANCE_START_FILTERS = 1 << 0,
 422         BALANCE_START_NOWARN  = 1 << 1
 423 };
 424
 425 static int do_balance(const char *path, struct btrfs_ioctl_balance_args *args,
 426                       unsigned flags)
 427 {
 428         int fd;
 429         int ret;
 430         int e;
 431         DIR *dirstream = NULL;
 432
 433         fd = btrfs_open_dir(path, &dirstream, 1);
 434         if (fd < 0)
 435                 return 1;
 436
 437         if (!(flags & BALANCE_START_FILTERS) && !(flags & BALANCE_START_NOWARN)) {
 438                 int delay = 10;
 439
 440                 printf("WARNING:\n\n");
 441                 printf("\tFull balance without filters requested. This operation is very\n");
 442                 printf("\tintense and takes potentially very long. It is recommended to\n");
 443                 printf("\tuse the balance filters to narrow down the balanced data.\n");
 444                 printf("\tUse 'btrfs balance start --full-balance' option to skip this\n");
 445                 printf("\twarning. The operation will start in %d seconds.\n", delay);
 446                 printf("\tUse Ctrl-C to stop it.\n");
 447                 while (delay) {
 448                         printf("%2d", delay--);
 449                         fflush(stdout);
 450                         sleep(1);
 451                 }
 452                 printf("\nStarting balance without any filters.\n");
 453         }
 454
 455         ret = ioctl(fd, BTRFS_IOC_BALANCE_V2, args);
 456         e = errno;
 457
 458         if (ret < 0) {
 459                 /*
 460                  * older kernels don't have the new balance ioctl, try the
 461                  * old one.  But, the old one doesn't know any filters, so
 462                  * don't fall back if they tried to use the fancy new things
 463                  */
 464                 if (e == ENOTTY && !(flags & BALANCE_START_FILTERS)) {
 465                         ret = do_balance_v1(fd);
 466                         if (ret == 0)
 467                                 goto out;
 468                         e = errno;
 469                 }
 470
 471                 if (e == ECANCELED) {
 472                         if (args->state & BTRFS_BALANCE_STATE_PAUSE_REQ)
 473                                 fprintf(stderr, "balance paused by user\n");
 474                         if (args->state & BTRFS_BALANCE_STATE_CANCEL_REQ)
 475                                 fprintf(stderr, "balance canceled by user\n");
 476                         ret = 0;
 477                 } else {
 478                         error("error during balancing '%s': %s", path, strerror(e));
 479                         if (e != EINPROGRESS)
 480                                 fprintf(stderr,
 481                         "There may be more info in syslog - try dmesg | tail\n");
 482                         ret = 1;
 483                 }
 484         } else {
 485                 printf("Done, had to relocate %llu out of %llu chunks\n",
 486                        (unsigned long long)args->stat.completed,
 487                        (unsigned long long)args->stat.considered);
 488                 ret = 0;
 489         }
 490
 491 out:
 492         close_file_or_dir(fd, dirstream);
 493         return ret;
 494 }
 495
 496 static const char * const cmd_balance_start_usage[] = {
 497         "btrfs balance start [options] <path>",
 498         "Balance chunks across the devices",
 499         "Balance and/or convert (change allocation profile of) chunks that",
 500         "passed all filters in a comma-separated list of filters for a",
 501         "particular chunk type.  If filter list is not given balance all",
 502         "chunks of that type.  In case none of the -d, -m or -s options is",
 503         "given balance all chunks in a filesystem. This is potentially",
 504         "long operation and the user is warned before this start, with",
 505         "a delay to stop it.",
 506         "",
 507         "-d[filters]    act on data chunks",
 508         "-m[filters]    act on metadata chunks",
 509         "-s[filters]    act on system chunks (only under -f)",
 510         "-v             be verbose",
 511         "-f             force reducing of metadata integrity",
 512         "--full-balance do not print warning and do not delay start",
 513         NULL
 514 };
 515
 516 static int cmd_balance_start(int argc, char **argv)
 517 {
 518         struct btrfs_ioctl_balance_args args;
 519         struct btrfs_balance_args *ptrs[] = { &args.data, &args.sys,
 520                                                 &args.meta, NULL };
 521         int force = 0;
 522         int verbose = 0;
 523         unsigned start_flags = 0;
 524         int i;
 525
 526         memset(&args, 0, sizeof(args));
 527
 528         optind = 1;
 529         while (1) {
 530                 enum { GETOPT_VAL_FULL_BALANCE = 256 };
 531                 static const struct option longopts[] = {
 532                         { "data", optional_argument, NULL, 'd'},
 533                         { "metadata", optional_argument, NULL, 'm' },
 534                         { "system", optional_argument, NULL, 's' },
 535                         { "force", no_argument, NULL, 'f' },
 536                         { "verbose", no_argument, NULL, 'v' },
 537                         { "full-balance", no_argument, NULL,
 538                                 GETOPT_VAL_FULL_BALANCE },
 539                         { NULL, 0, NULL, 0 }
 540                 };
 541
 542                 int opt = getopt_long(argc, argv, "d::s::m::fv", longopts, NULL);
 543                 if (opt < 0)
 544                         break;
 545
 546                 switch (opt) {
 547                 case 'd':
 548                         start_flags |= BALANCE_START_FILTERS;
 549                         args.flags |= BTRFS_BALANCE_DATA;
 550
 551                         if (parse_filters(optarg, &args.data))
 552                                 return 1;
 553                         break;
 554                 case 's':
 555                         start_flags |= BALANCE_START_FILTERS;
 556                         args.flags |= BTRFS_BALANCE_SYSTEM;
 557
 558                         if (parse_filters(optarg, &args.sys))
 559                                 return 1;
 560                         break;
 561                 case 'm':
 562                         start_flags |= BALANCE_START_FILTERS;
 563                         args.flags |= BTRFS_BALANCE_METADATA;
 564
 565                         if (parse_filters(optarg, &args.meta))
 566                                 return 1;
 567                         break;
 568                 case 'f':
 569                         force = 1;
 570                         break;
 571                 case 'v':
 572                         verbose = 1;
 573                         break;
 574                 case GETOPT_VAL_FULL_BALANCE:
 575                         start_flags |= BALANCE_START_NOWARN;
 576                         break;
 577                 default:
 578                         usage(cmd_balance_start_usage);
 579                 }
 580         }
 581
 582         if (check_argc_exact(argc - optind, 1))
 583                 usage(cmd_balance_start_usage);
 584
 585         /*
 586          * allow -s only under --force, otherwise do with system chunks
 587          * the same thing we were ordered to do with meta chunks
 588          */
 589         if (args.flags & BTRFS_BALANCE_SYSTEM) {
 590                 if (!force) {
 591                         error(
 592                             "Refusing to explicitly operate on system chunks.\n"
 593                             "Pass --force if you really want to do that.");
 594                         return 1;
 595                 }
 596         } else if (args.flags & BTRFS_BALANCE_METADATA) {
 597                 args.flags |= BTRFS_BALANCE_SYSTEM;
 598                 memcpy(&args.sys, &args.meta,
 599                         sizeof(struct btrfs_balance_args));
 600         }
 601
 602         if (!(start_flags & BALANCE_START_FILTERS)) {
 603                 /* relocate everything - no filters */
 604                 args.flags |= BTRFS_BALANCE_TYPE_MASK;
 605         }
 606
 607         /* drange makes sense only when devid is set */
 608         for (i = 0; ptrs[i]; i++) {
 609                 if ((ptrs[i]->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
 610                     !(ptrs[i]->flags & BTRFS_BALANCE_ARGS_DEVID)) {
 611                         error("drange filter must be used with devid filter");
 612                         return 1;
 613                 }
 614         }
 615
 616         /* soft makes sense only when convert for corresponding type is set */
 617         for (i = 0; ptrs[i]; i++) {
 618                 if ((ptrs[i]->flags & BTRFS_BALANCE_ARGS_SOFT) &&
 619                     !(ptrs[i]->flags & BTRFS_BALANCE_ARGS_CONVERT)) {
 620                         error("'soft' option can be used only when converting profiles");
 621                         return 1;
 622                 }
 623         }
 624
 625         if (force)
 626                 args.flags |= BTRFS_BALANCE_FORCE;
 627         if (verbose)
 628                 dump_ioctl_balance_args(&args);
 629
 630         return do_balance(argv[optind], &args, start_flags);
 631 }
 632
 633 static const char * const cmd_balance_pause_usage[] = {
 634         "btrfs balance pause <path>",
 635         "Pause running balance",
 636         NULL
 637 };
 638
 639 static int cmd_balance_pause(int argc, char **argv)
 640 {
 641         const char *path;
 642         int fd;
 643         int ret;
 644         int e;
 645         DIR *dirstream = NULL;
 646
 647         clean_args_no_options(argc, argv, cmd_balance_pause_usage);
 648
 649         if (check_argc_exact(argc - optind, 1))
 650                 usage(cmd_balance_pause_usage);
 651
 652         path = argv[optind];
 653
 654         fd = btrfs_open_dir(path, &dirstream, 1);
 655         if (fd < 0)
 656                 return 1;
 657
 658         ret = ioctl(fd, BTRFS_IOC_BALANCE_CTL, BTRFS_BALANCE_CTL_PAUSE);
 659         e = errno;
 660         close_file_or_dir(fd, dirstream);
 661
 662         if (ret < 0) {
 663                 error("balance pause on '%s' failed: %s", path,
 664                         (e == ENOTCONN) ? "Not running" : strerror(e));
 665                 if (e == ENOTCONN)
 666                         return 2;
 667                 else
 668                         return 1;
 669         }
 670
 671         return 0;
 672 }
 673
 674 static const char * const cmd_balance_cancel_usage[] = {
 675         "btrfs balance cancel <path>",
 676         "Cancel running or paused balance",
 677         NULL
 678 };
 679
 680 static int cmd_balance_cancel(int argc, char **argv)
 681 {
 682         const char *path;
 683         int fd;
 684         int ret;
 685         int e;
 686         DIR *dirstream = NULL;
 687
 688         clean_args_no_options(argc, argv, cmd_balance_cancel_usage);
 689
 690         if (check_argc_exact(argc - optind, 1))
 691                 usage(cmd_balance_cancel_usage);
 692
 693         path = argv[optind];
 694
 695         fd = btrfs_open_dir(path, &dirstream, 1);
 696         if (fd < 0)
 697                 return 1;
 698
 699         ret = ioctl(fd, BTRFS_IOC_BALANCE_CTL, BTRFS_BALANCE_CTL_CANCEL);
 700         e = errno;
 701         close_file_or_dir(fd, dirstream);
 702
 703         if (ret < 0) {
 704                 error("balance cancel on '%s' failed: %s", path,
 705                         (e == ENOTCONN) ? "Not in progress" : strerror(e));
 706                 if (e == ENOTCONN)
 707                         return 2;
 708                 else
 709                         return 1;
 710         }
 711
 712         return 0;
 713 }
 714
 715 static const char * const cmd_balance_resume_usage[] = {
 716         "btrfs balance resume <path>",
 717         "Resume interrupted balance",
 718         NULL
 719 };
 720
 721 static int cmd_balance_resume(int argc, char **argv)
 722 {
 723         struct btrfs_ioctl_balance_args args;
 724         const char *path;
 725         DIR *dirstream = NULL;
 726         int fd;
 727         int ret;
 728         int e;
 729
 730         clean_args_no_options(argc, argv, cmd_balance_resume_usage);
 731
 732         if (check_argc_exact(argc - optind, 1))
 733                 usage(cmd_balance_resume_usage);
 734
 735         path = argv[optind];
 736
 737         fd = btrfs_open_dir(path, &dirstream, 1);
 738         if (fd < 0)
 739                 return 1;
 740
 741         memset(&args, 0, sizeof(args));
 742         args.flags |= BTRFS_BALANCE_RESUME;
 743
 744         ret = ioctl(fd, BTRFS_IOC_BALANCE_V2, &args);
 745         e = errno;
 746         close_file_or_dir(fd, dirstream);
 747
 748         if (ret < 0) {
 749                 if (e == ECANCELED) {
 750                         if (args.state & BTRFS_BALANCE_STATE_PAUSE_REQ)
 751                                 fprintf(stderr, "balance paused by user\n");
 752                         if (args.state & BTRFS_BALANCE_STATE_CANCEL_REQ)
 753                                 fprintf(stderr, "balance canceled by user\n");
 754                 } else if (e == ENOTCONN || e == EINPROGRESS) {
 755                         error("balance resume on '%s' failed: %s", path,
 756                                 (e == ENOTCONN) ? "Not in progress" :
 757                                                   "Already running");
 758                         if (e == ENOTCONN)
 759                                 return 2;
 760                         else
 761                                 return 1;
 762                 } else {
 763                         error("error during balancing '%s': %s\n"
 764                           "There may be more info in syslog - try dmesg | tail",
 765                                 path, strerror(e));
 766                         return 1;
 767                 }
 768         } else {
 769                 printf("Done, had to relocate %llu out of %llu chunks\n",
 770                        (unsigned long long)args.stat.completed,
 771                        (unsigned long long)args.stat.considered);
 772         }
 773
 774         return 0;
 775 }
 776
 777 static const char * const cmd_balance_status_usage[] = {
 778         "btrfs balance status [-v] <path>",
 779         "Show status of running or paused balance",
 780         "",
 781         "-v     be verbose",
 782         NULL
 783 };
 784
 785 /* Checks the status of the balance if any
 786  * return codes:
 787  *   2 : Error failed to know if there is any pending balance
 788  *   1 : Successful to know status of a pending balance
 789  *   0 : When there is no pending balance or completed
 790  */
 791 static int cmd_balance_status(int argc, char **argv)
 792 {
 793         struct btrfs_ioctl_balance_args args;
 794         const char *path;
 795         DIR *dirstream = NULL;
 796         int fd;
 797         int verbose = 0;
 798         int ret;
 799         int e;
 800
 801         optind = 1;
 802         while (1) {
 803                 int opt;
 804                 static const struct option longopts[] = {
 805                         { "verbose", no_argument, NULL, 'v' },
 806                         { NULL, 0, NULL, 0 }
 807                 };
 808
 809                 opt = getopt_long(argc, argv, "v", longopts, NULL);
 810                 if (opt < 0)
 811                         break;
 812
 813                 switch (opt) {
 814                 case 'v':
 815                         verbose = 1;
 816                         break;
 817                 default:
 818                         usage(cmd_balance_status_usage);
 819                 }
 820         }
 821
 822         if (check_argc_exact(argc - optind, 1))
 823                 usage(cmd_balance_status_usage);
 824
 825         path = argv[optind];
 826
 827         fd = btrfs_open_dir(path, &dirstream, 1);
 828         if (fd < 0)
 829                 return 2;
 830
 831         ret = ioctl(fd, BTRFS_IOC_BALANCE_PROGRESS, &args);
 832         e = errno;
 833         close_file_or_dir(fd, dirstream);
 834
 835         if (ret < 0) {
 836                 if (e == ENOTCONN) {
 837                         printf("No balance found on '%s'\n", path);
 838                         return 0;
 839                 }
 840                 error("balance status on '%s' failed: %s", path, strerror(e));
 841                 return 2;
 842         }
 843
 844         if (args.state & BTRFS_BALANCE_STATE_RUNNING) {
 845                 printf("Balance on '%s' is running", path);
 846                 if (args.state & BTRFS_BALANCE_STATE_CANCEL_REQ)
 847                         printf(", cancel requested\n");
 848                 else if (args.state & BTRFS_BALANCE_STATE_PAUSE_REQ)
 849                         printf(", pause requested\n");
 850                 else
 851                         printf("\n");
 852         } else {
 853                 printf("Balance on '%s' is paused\n", path);
 854         }
 855
 856         printf("%llu out of about %llu chunks balanced (%llu considered), "
 857                "%3.f%% left\n", (unsigned long long)args.stat.completed,
 858                (unsigned long long)args.stat.expected,
 859                (unsigned long long)args.stat.considered,
 860                100 * (1 - (float)args.stat.completed/args.stat.expected));
 861
 862         if (verbose)
 863                 dump_ioctl_balance_args(&args);
 864
 865         return 1;
 866 }
 867
 868 static int cmd_balance_full(int argc, char **argv)
 869 {
 870         struct btrfs_ioctl_balance_args args;
 871
 872         memset(&args, 0, sizeof(args));
 873         args.flags |= BTRFS_BALANCE_TYPE_MASK;
 874
 875         return do_balance(argv[1], &args, BALANCE_START_NOWARN);
 876 }
 877
 878 static const char balance_cmd_group_info[] =
 879 "balance data across devices, or change block groups using filters";
 880
 881 const struct cmd_group balance_cmd_group = {
 882         balance_cmd_group_usage, balance_cmd_group_info, {
 883                 { "start", cmd_balance_start, cmd_balance_start_usage, NULL, 0 },
 884                 { "pause", cmd_balance_pause, cmd_balance_pause_usage, NULL, 0 },
 885                 { "cancel", cmd_balance_cancel, cmd_balance_cancel_usage, NULL, 0 },
 886                 { "resume", cmd_balance_resume, cmd_balance_resume_usage, NULL, 0 },
 887                 { "status", cmd_balance_status, cmd_balance_status_usage, NULL, 0 },
 888                 { "--full-balance", cmd_balance_full, NULL, NULL, 1 },
 889                 NULL_CMD_STRUCT
 890         }
 891 };
 892
 893 int cmd_balance(int argc, char **argv)
 894 {
 895         if (argc == 2 && strcmp("start", argv[1]) != 0) {
 896                 /* old 'btrfs filesystem balance <path>' syntax */
 897                 struct btrfs_ioctl_balance_args args;
 898
 899                 memset(&args, 0, sizeof(args));
 900                 args.flags |= BTRFS_BALANCE_TYPE_MASK;
 901
 902                 return do_balance(argv[1], &args, 0);
 903         }
 904
 905         return handle_command_group(&balance_cmd_group, argc, argv);
 906 }