btrfs.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 #define _GNU_SOURCE
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21
  22 #include "kerncompat.h"
  23 #include "btrfs_cmds.h"
  24 #include "version.h"
  25
  26 #define BASIC_HELP 0
  27 #define ADVANCED_HELP 1
  28
  29 typedef int (*CommandFunction)(int argc, char **argv);
  30
  31 struct Command {
  32         CommandFunction func;   /* function which implements the command */
  33         int     nargs;          /* if == 999, any number of arguments
  34                                    if >= 0, number of arguments,
  35                                    if < 0, _minimum_ number of arguments */
  36         char    *verb;          /* verb */
  37         char    *help;          /* help lines; from the 2nd line onward they
  38                                    are automatically indented */
  39         char    *adv_help;      /* advanced help message; from the 2nd line
  40                                    onward they are automatically indented */
  41
  42         /* the following fields are run-time filled by the program */
  43         char    **cmds;         /* array of subcommands */
  44         int     ncmds;          /* number of subcommand */
  45 };
  46
  47 static struct Command commands[] = {
  48
  49         /*
  50                 avoid short commands different for the case only
  51         */
  52         { do_clone, -2,
  53           "subvolume snapshot", "[-r] <source> [<dest>/]<name>\n"
  54                 "Create a writable/readonly snapshot of the subvolume <source> with\n"
  55                 "the name <name> in the <dest> directory.",
  56           NULL
  57         },
  58         { do_delete_subvolume, 1,
  59           "subvolume delete", "<subvolume>\n"
  60                 "Delete the subvolume <subvolume>.",
  61           NULL
  62         },
  63         { do_create_subvol, 1,
  64           "subvolume create", "[<dest>/]<name>\n"
  65                 "Create a subvolume in <dest> (or the current directory if\n"
  66                 "not passed).",
  67           NULL
  68         },
  69         { do_subvol_list, -1, "subvolume list", "[-p] <path>\n"
  70                 "List the snapshot/subvolume of a filesystem.",
  71                 "[-p] <path>\n"
  72                 "List the snapshot/subvolume of a filesystem.\n"
  73                 "-p        print parent ID"
  74         },
  75         { do_set_default_subvol, 2,
  76           "subvolume set-default", "<id> <path>\n"
  77                 "Set the subvolume of the filesystem <path> which will be mounted\n"
  78                 "as default.",
  79           NULL
  80         },
  81         { do_find_newer, 2, "subvolume find-new", "<path> <last_gen>\n"
  82                 "List the recently modified files in a filesystem.",
  83           NULL
  84         },
  85         { do_defrag, -1,
  86           "filesystem defragment", "[-vf] [-c[zlib,lzo]] [-s start] [-l len] [-t size] <file>|<dir> [<file>|<dir>...]\n"
  87                 "Defragment a file or a directory.",
  88                 "[-vcf] [-s start] [-l len] [-t size] <file>|<dir> [<file>|<dir>...]\n"
  89                 "Defragment file data or directory metadata.\n"
  90                 "-v         be verbose\n"
  91                 "-c         compress the file while defragmenting\n"
  92                 "-f         flush data to disk immediately after defragmenting\n"
  93                 "-s start   defragment only from byte onward\n"
  94                 "-l len     defragment only up to len bytes\n"
  95                 "-t size    minimal size of file to be considered for defragmenting\n"
  96         },
  97         { do_get_default_subvol, 1, "subvolume get-default", "<path>\n"
  98                 "Get the default subvolume of a filesystem."
  99         },
 100         { do_fssync, 1,
 101           "filesystem sync", "<path>\n"
 102                 "Force a sync on the filesystem <path>.",
 103           NULL
 104         },
 105         { do_resize, 2,
 106           "filesystem resize", "[+/-]<newsize>[gkm]|max <filesystem>\n"
 107                 "Resize the file system. If 'max' is passed, the filesystem\n"
 108                 "will occupe all available space on the device.",
 109           NULL
 110         },
 111         { do_show_filesystem, 999,
 112           "filesystem show", "[--all-devices][<uuid>|<label>]\n"
 113                 "Show the info of a btrfs filesystem. If no argument\n"
 114                 "is passed, info of all the btrfs filesystem are shown.",
 115           NULL
 116         },
 117         { do_df_filesystem, 1,
 118           "filesystem df", "<path>\n"
 119                 "Show space usage information for a mount point.",
 120           NULL
 121         },
 122         { do_balance, 1,
 123           "filesystem balance", "<path>\n"
 124                 "Balance the chunks across the device.",
 125           NULL
 126         },
 127         { do_change_label, -1,
 128           "filesystem label", "<device> [<newlabel>]\n"
 129           "With one argument, get the label of filesystem on <device>.\n"
 130           "If <newlabel> is passed, set the filesystem label to <newlabel>.\n"
 131           "The filesystem must be unmounted.\n"
 132         },
 133         { do_scrub_start, -1,
 134           "scrub start", "[-Bdqr] <path>|<device>\n"
 135                 "Start a new scrub.",
 136                 "\n-B  do not background\n"
 137                 "-d  stats per device (-B only)\n"
 138                 "-q  quiet\n"
 139                 "-r  read only mode\n"
 140         },
 141         { do_scrub_cancel, 1,
 142           "scrub cancel", "<path>|<device>\n"
 143                 "Cancel a running scrub.",
 144           NULL
 145         },
 146         { do_scrub_resume, -1,
 147           "scrub resume", "[-Bdqr] <path>|<device>\n"
 148                 "Resume previously canceled or interrupted scrub.",
 149           NULL
 150         },
 151         { do_scrub_status, -1,
 152           "scrub status", "[-d] <path>|<device>\n"
 153                 "Show status of running or finished scrub.",
 154           NULL
 155         },
 156         { do_scan, 999,
 157           "device scan", "[<device>...]\n"
 158                 "Scan all device for or the passed device for a btrfs\n"
 159                 "filesystem.",
 160           NULL
 161         },
 162         { do_add_volume, -2,
 163           "device add", "<device> [<device>...] <path>\n"
 164                 "Add a device to a filesystem.",
 165           NULL
 166         },
 167         { do_remove_volume, -2,
 168           "device delete", "<device> [<device>...] <path>\n"
 169                 "Remove a device from a filesystem.",
 170           NULL
 171         },
 172         { 0, 0, 0, 0 }
 173 };
 174
 175 static char *get_prgname(char *programname)
 176 {
 177         char    *np;
 178         np = strrchr(programname,'/');
 179         if(!np)
 180                 np = programname;
 181         else
 182                 np++;
 183
 184         return np;
 185 }
 186
 187 static void print_help(char *programname, struct Command *cmd, int helptype)
 188 {
 189         char    *pc;
 190
 191         printf("\t%s %s ", programname, cmd->verb );
 192
 193         if (helptype == ADVANCED_HELP && cmd->adv_help)
 194                 for(pc = cmd->adv_help; *pc; pc++){
 195                         putchar(*pc);
 196                         if(*pc == '\n')
 197                                 printf("\t\t");
 198                 }
 199         else
 200                 for(pc = cmd->help; *pc; pc++){
 201                         putchar(*pc);
 202                         if(*pc == '\n')
 203                                 printf("\t\t");
 204                 }
 205
 206         putchar('\n');
 207 }
 208
 209 static void help(char *np)
 210 {
 211         struct Command *cp;
 212
 213         printf("Usage:\n");
 214         for( cp = commands; cp->verb; cp++ )
 215                 print_help(np, cp, BASIC_HELP);
 216
 217         printf("\n\t%s help|--help|-h\n\t\tShow the help.\n",np);
 218         printf("\n\t%s <cmd> --help\n\t\tShow detailed help for a command or\n\t\t"
 219                "subset of commands.\n",np);
 220         printf("\n%s\n", BTRFS_BUILD_VERSION);
 221 }
 222
 223 static int split_command(char *cmd, char ***commands)
 224 {
 225         int     c, l;
 226         char    *p, *s;
 227
 228         for( *commands = 0, l = c = 0, p = s = cmd ; ; p++, l++ ){
 229                 if ( *p && *p != ' ' )
 230                         continue;
 231
 232                 /* c + 2 so that we have room for the null */
 233                 (*commands) = realloc( (*commands), sizeof(char *)*(c + 2));
 234                 (*commands)[c] = strndup(s, l);
 235                 c++;
 236                 l = 0;
 237                 s = p+1;
 238                 if( !*p ) break;
 239         }
 240
 241         (*commands)[c] = 0;
 242         return c;
 243 }
 244
 245 /*
 246         This function checks if the passed command is ambiguous
 247 */
 248 static int check_ambiguity(struct Command *cmd, char **argv){
 249         int             i;
 250         struct Command  *cp;
 251         /* check for ambiguity */
 252         for( i = 0 ; i < cmd->ncmds ; i++ ){
 253                 int match;
 254                 for( match = 0, cp = commands; cp->verb; cp++ ){
 255                         int     j, skip;
 256                         char    *s1, *s2;
 257
 258                         if( cp->ncmds < i )
 259                                 continue;
 260
 261                         for( skip = 0, j = 0 ; j < i ; j++ )
 262                                 if( strcmp(cmd->cmds[j], cp->cmds[j])){
 263                                         skip=1;
 264                                         break;
 265                                 }
 266                         if(skip)
 267                                 continue;
 268
 269                         if( !strcmp(cmd->cmds[i], cp->cmds[i]))
 270                                 continue;
 271                         for(s2 = cp->cmds[i], s1 = argv[i+1];
 272                                 *s1 == *s2 && *s1; s1++, s2++ ) ;
 273                         if( !*s1 )
 274                                 match++;
 275                 }
 276                 if(match){
 277                         int j;
 278                         fprintf(stderr, "ERROR: in command '");
 279                         for( j = 0 ; j <= i ; j++ )
 280                                 fprintf(stderr, "%s%s",j?" ":"", argv[j+1]);
 281                         fprintf(stderr, "', '%s' is ambiguous\n",argv[j]);
 282                         return -2;
 283                 }
 284         }
 285         return 0;
 286 }
 287
 288 /*
 289  * This function, compacts the program name and the command in the first
 290  * element of the '*av' array
 291  */
 292 static int prepare_args(int *ac, char ***av, char *prgname, struct Command *cmd ){
 293
 294         char    **ret;
 295         int     i;
 296         char    *newname;
 297
 298         ret = (char **)malloc(sizeof(char*)*(*ac+1));
 299         newname = (char*)malloc(strlen(prgname)+strlen(cmd->verb)+2);
 300         if( !ret || !newname ){
 301                 free(ret);
 302                 free(newname);
 303                 return -1;
 304         }
 305
 306         ret[0] = newname;
 307         for(i=0; i < *ac ; i++ )
 308                 ret[i+1] = (*av)[i];
 309
 310         strcpy(newname, prgname);
 311         strcat(newname, " ");
 312         strcat(newname, cmd->verb);
 313
 314         (*ac)++;
 315         *av = ret;
 316
 317         return 0;
 318
 319 }
 320
 321
 322
 323 /*
 324         This function performs the following jobs:
 325         - show the help if '--help' or 'help' or '-h' are passed
 326         - verify that a command is not ambiguous, otherwise show which
 327           part of the command is ambiguous
 328         - if after a (even partial) command there is '--help' show detailed help
 329           for all the matching commands
 330         - if the command doesn't match show an error
 331         - finally, if a command matches, they return which command matched and
 332           the arguments
 333
 334         The function return 0 in case of help is requested; <0 in case
 335         of uncorrect command; >0 in case of matching commands
 336         argc, argv are the arg-counter and arg-vector (input)
 337         *nargs_ is the number of the arguments after the command (output)
 338         **cmd_  is the invoked command (output)
 339         ***args_ are the arguments after the command
 340
 341 */
 342 static int parse_args(int argc, char **argv,
 343                       CommandFunction *func_,
 344                       int *nargs_, char **cmd_, char ***args_ )
 345 {
 346         struct Command  *cp;
 347         struct Command  *matchcmd=0;
 348         char            *prgname = get_prgname(argv[0]);
 349         int             i=0, helprequested=0;
 350
 351         if( argc < 2 || !strcmp(argv[1], "help") ||
 352                 !strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")){
 353                 help(prgname);
 354                 return 0;
 355         }
 356
 357         for( cp = commands; cp->verb; cp++ )
 358                 if( !cp->ncmds)
 359                         cp->ncmds = split_command(cp->verb, &(cp->cmds));
 360
 361         for( cp = commands; cp->verb; cp++ ){
 362                 int     match;
 363
 364                 if( argc-1 < cp->ncmds )
 365                         continue;
 366                 for( match = 1, i = 0 ; i < cp->ncmds ; i++ ){
 367                         char    *s1, *s2;
 368                         s1 = cp->cmds[i];
 369                         s2 = argv[i+1];
 370
 371                         for(s2 = cp->cmds[i], s1 = argv[i+1];
 372                                 *s1 == *s2 && *s1;
 373                                 s1++, s2++ ) ;
 374                         if( *s1 ){
 375                                 match=0;
 376                                 break;
 377                         }
 378                 }
 379
 380                 /* If you understand why this code works ...
 381                         you are a genious !! */
 382                 if(argc>i+1 && !strcmp(argv[i+1],"--help")){
 383                         if(!helprequested)
 384                                 printf("Usage:\n");
 385                         print_help(prgname, cp, ADVANCED_HELP);
 386                         helprequested=1;
 387                         continue;
 388                 }
 389
 390                 if(!match)
 391                         continue;
 392
 393                 matchcmd = cp;
 394                 *nargs_  = argc-matchcmd->ncmds-1;
 395                 *cmd_ = matchcmd->verb;
 396                 *args_ = argv+matchcmd->ncmds+1;
 397                 *func_ = cp->func;
 398
 399                 break;
 400         }
 401
 402         if(helprequested){
 403                 printf("\n%s\n", BTRFS_BUILD_VERSION);
 404                 return 0;
 405         }
 406
 407         if(!matchcmd){
 408                 fprintf( stderr, "ERROR: unknown command '%s'\n",argv[1]);
 409                 help(prgname);
 410                 return -1;
 411         }
 412
 413         if(check_ambiguity(matchcmd, argv))
 414                 return -2;
 415
 416         /* check the number of argument */
 417         if (matchcmd->nargs < 0 && matchcmd->nargs < -*nargs_ ){
 418                 fprintf(stderr, "ERROR: '%s' requires minimum %d arg(s)\n",
 419                         matchcmd->verb, -matchcmd->nargs);
 420                         return -2;
 421         }
 422         if(matchcmd->nargs >= 0 && matchcmd->nargs != *nargs_ && matchcmd->nargs != 999){
 423                 fprintf(stderr, "ERROR: '%s' requires %d arg(s)\n",
 424                         matchcmd->verb, matchcmd->nargs);
 425                         return -2;
 426         }
 427
 428         if (prepare_args( nargs_, args_, prgname, matchcmd )){
 429                 fprintf(stderr, "ERROR: not enough memory\\n");
 430                 return -20;
 431         }
 432
 433
 434         return 1;
 435 }
 436 int main(int ac, char **av )
 437 {
 438
 439         char            *cmd=0, **args=0;
 440         int             nargs=0, r;
 441         CommandFunction func=0;
 442
 443         r = parse_args(ac, av, &func, &nargs, &cmd, &args);
 444         if( r <= 0 ){
 445                 /* error or no command to parse*/
 446                 exit(-r);
 447         }
 448
 449         exit(func(nargs, args));
 450
 451 }
 452