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_fssync, 1,
  98           "filesystem sync", "<path>\n"
  99                 "Force a sync on the filesystem <path>.",
 100           NULL
 101         },
 102         { do_resize, 2,
 103           "filesystem resize", "[+/-]<newsize>[gkm]|max <filesystem>\n"
 104                 "Resize the file system. If 'max' is passed, the filesystem\n"
 105                 "will occupe all available space on the device.",
 106           NULL
 107         },
 108         { do_show_filesystem, 999,
 109           "filesystem show", "[<device>|<uuid>|<label>]\n"
 110                 "Show the info of a btrfs filesystem. If no argument\n"
 111                 "is passed, info of all the btrfs filesystem are shown.",
 112           NULL
 113         },
 114         { do_df_filesystem, 1,
 115           "filesystem df", "<path>\n"
 116                 "Show space usage information for a mount point.",
 117           NULL
 118         },
 119         { do_balance, 1,
 120           "filesystem balance", "<path>\n"
 121                 "Balance the chunks across the device.",
 122           NULL
 123         },
 124         { do_change_label, -1,
 125           "filesystem label", "<device> [<newlabel>]\n"
 126           "With one argument, get the label of filesystem on <device>.\n"
 127           "If <newlabel> is passed, set the filesystem label to <newlabel>.\n"
 128           "The filesystem must be unmounted.\n"
 129         },
 130         { do_scrub_start, -1,
 131           "scrub start", "[-Bdqr] <path>|<device>\n"
 132                 "Start a new scrub.",
 133                 "\n-B  do not background\n"
 134                 "-d  stats per device (-B only)\n"
 135                 "-q  quiet\n"
 136                 "-r  read only mode\n"
 137         },
 138         { do_scrub_cancel, 1,
 139           "scrub cancel", "<path>|<device>\n"
 140                 "Cancel a running scrub.",
 141           NULL
 142         },
 143         { do_scrub_resume, -1,
 144           "scrub resume", "[-Bdqr] <path>|<device>\n"
 145                 "Resume previously canceled or interrupted scrub.",
 146           NULL
 147         },
 148         { do_scrub_status, -1,
 149           "scrub status", "[-d] <path>|<device>\n"
 150                 "Show status of running or finished scrub.",
 151           NULL
 152         },
 153         { do_scan, 999,
 154           "device scan", "[<device>...]\n"
 155                 "Scan all device for or the passed device for a btrfs\n"
 156                 "filesystem.",
 157           NULL
 158         },
 159         { do_add_volume, -2,
 160           "device add", "<device> [<device>...] <path>\n"
 161                 "Add a device to a filesystem.",
 162           NULL
 163         },
 164         { do_remove_volume, -2,
 165           "device delete", "<device> [<device>...] <path>\n"
 166                 "Remove a device from a filesystem.",
 167           NULL
 168         },
 169         { 0, 0, 0, 0 }
 170 };
 171
 172 static char *get_prgname(char *programname)
 173 {
 174         char    *np;
 175         np = strrchr(programname,'/');
 176         if(!np)
 177                 np = programname;
 178         else
 179                 np++;
 180
 181         return np;
 182 }
 183
 184 static void print_help(char *programname, struct Command *cmd, int helptype)
 185 {
 186         char    *pc;
 187
 188         printf("\t%s %s ", programname, cmd->verb );
 189
 190         if (helptype == ADVANCED_HELP && cmd->adv_help)
 191                 for(pc = cmd->adv_help; *pc; pc++){
 192                         putchar(*pc);
 193                         if(*pc == '\n')
 194                                 printf("\t\t");
 195                 }
 196         else
 197                 for(pc = cmd->help; *pc; pc++){
 198                         putchar(*pc);
 199                         if(*pc == '\n')
 200                                 printf("\t\t");
 201                 }
 202
 203         putchar('\n');
 204 }
 205
 206 static void help(char *np)
 207 {
 208         struct Command *cp;
 209
 210         printf("Usage:\n");
 211         for( cp = commands; cp->verb; cp++ )
 212                 print_help(np, cp, BASIC_HELP);
 213
 214         printf("\n\t%s help|--help|-h\n\t\tShow the help.\n",np);
 215         printf("\n\t%s <cmd> --help\n\t\tShow detailed help for a command or\n\t\t"
 216                "subset of commands.\n",np);
 217         printf("\n%s\n", BTRFS_BUILD_VERSION);
 218 }
 219
 220 static int split_command(char *cmd, char ***commands)
 221 {
 222         int     c, l;
 223         char    *p, *s;
 224
 225         for( *commands = 0, l = c = 0, p = s = cmd ; ; p++, l++ ){
 226                 if ( *p && *p != ' ' )
 227                         continue;
 228
 229                 /* c + 2 so that we have room for the null */
 230                 (*commands) = realloc( (*commands), sizeof(char *)*(c + 2));
 231                 (*commands)[c] = strndup(s, l);
 232                 c++;
 233                 l = 0;
 234                 s = p+1;
 235                 if( !*p ) break;
 236         }
 237
 238         (*commands)[c] = 0;
 239         return c;
 240 }
 241
 242 /*
 243         This function checks if the passed command is ambiguous
 244 */
 245 static int check_ambiguity(struct Command *cmd, char **argv){
 246         int             i;
 247         struct Command  *cp;
 248         /* check for ambiguity */
 249         for( i = 0 ; i < cmd->ncmds ; i++ ){
 250                 int match;
 251                 for( match = 0, cp = commands; cp->verb; cp++ ){
 252                         int     j, skip;
 253                         char    *s1, *s2;
 254
 255                         if( cp->ncmds < i )
 256                                 continue;
 257
 258                         for( skip = 0, j = 0 ; j < i ; j++ )
 259                                 if( strcmp(cmd->cmds[j], cp->cmds[j])){
 260                                         skip=1;
 261                                         break;
 262                                 }
 263                         if(skip)
 264                                 continue;
 265
 266                         if( !strcmp(cmd->cmds[i], cp->cmds[i]))
 267                                 continue;
 268                         for(s2 = cp->cmds[i], s1 = argv[i+1];
 269                                 *s1 == *s2 && *s1; s1++, s2++ ) ;
 270                         if( !*s1 )
 271                                 match++;
 272                 }
 273                 if(match){
 274                         int j;
 275                         fprintf(stderr, "ERROR: in command '");
 276                         for( j = 0 ; j <= i ; j++ )
 277                                 fprintf(stderr, "%s%s",j?" ":"", argv[j+1]);
 278                         fprintf(stderr, "', '%s' is ambiguous\n",argv[j]);
 279                         return -2;
 280                 }
 281         }
 282         return 0;
 283 }
 284
 285 /*
 286  * This function, compacts the program name and the command in the first
 287  * element of the '*av' array
 288  */
 289 static int prepare_args(int *ac, char ***av, char *prgname, struct Command *cmd ){
 290
 291         char    **ret;
 292         int     i;
 293         char    *newname;
 294
 295         ret = (char **)malloc(sizeof(char*)*(*ac+1));
 296         newname = (char*)malloc(strlen(prgname)+strlen(cmd->verb)+2);
 297         if( !ret || !newname ){
 298                 free(ret);
 299                 free(newname);
 300                 return -1;
 301         }
 302
 303         ret[0] = newname;
 304         for(i=0; i < *ac ; i++ )
 305                 ret[i+1] = (*av)[i];
 306
 307         strcpy(newname, prgname);
 308         strcat(newname, " ");
 309         strcat(newname, cmd->verb);
 310
 311         (*ac)++;
 312         *av = ret;
 313
 314         return 0;
 315
 316 }
 317
 318
 319
 320 /*
 321         This function performs the following jobs:
 322         - show the help if '--help' or 'help' or '-h' are passed
 323         - verify that a command is not ambiguous, otherwise show which
 324           part of the command is ambiguous
 325         - if after a (even partial) command there is '--help' show detailed help
 326           for all the matching commands
 327         - if the command doesn't match show an error
 328         - finally, if a command matches, they return which command matched and
 329           the arguments
 330
 331         The function return 0 in case of help is requested; <0 in case
 332         of uncorrect command; >0 in case of matching commands
 333         argc, argv are the arg-counter and arg-vector (input)
 334         *nargs_ is the number of the arguments after the command (output)
 335         **cmd_  is the invoked command (output)
 336         ***args_ are the arguments after the command
 337
 338 */
 339 static int parse_args(int argc, char **argv,
 340                       CommandFunction *func_,
 341                       int *nargs_, char **cmd_, char ***args_ )
 342 {
 343         struct Command  *cp;
 344         struct Command  *matchcmd=0;
 345         char            *prgname = get_prgname(argv[0]);
 346         int             i=0, helprequested=0;
 347
 348         if( argc < 2 || !strcmp(argv[1], "help") ||
 349                 !strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")){
 350                 help(prgname);
 351                 return 0;
 352         }
 353
 354         for( cp = commands; cp->verb; cp++ )
 355                 if( !cp->ncmds)
 356                         cp->ncmds = split_command(cp->verb, &(cp->cmds));
 357
 358         for( cp = commands; cp->verb; cp++ ){
 359                 int     match;
 360
 361                 if( argc-1 < cp->ncmds )
 362                         continue;
 363                 for( match = 1, i = 0 ; i < cp->ncmds ; i++ ){
 364                         char    *s1, *s2;
 365                         s1 = cp->cmds[i];
 366                         s2 = argv[i+1];
 367
 368                         for(s2 = cp->cmds[i], s1 = argv[i+1];
 369                                 *s1 == *s2 && *s1;
 370                                 s1++, s2++ ) ;
 371                         if( *s1 ){
 372                                 match=0;
 373                                 break;
 374                         }
 375                 }
 376
 377                 /* If you understand why this code works ...
 378                         you are a genious !! */
 379                 if(argc>i+1 && !strcmp(argv[i+1],"--help")){
 380                         if(!helprequested)
 381                                 printf("Usage:\n");
 382                         print_help(prgname, cp, ADVANCED_HELP);
 383                         helprequested=1;
 384                         continue;
 385                 }
 386
 387                 if(!match)
 388                         continue;
 389
 390                 matchcmd = cp;
 391                 *nargs_  = argc-matchcmd->ncmds-1;
 392                 *cmd_ = matchcmd->verb;
 393                 *args_ = argv+matchcmd->ncmds+1;
 394                 *func_ = cp->func;
 395
 396                 break;
 397         }
 398
 399         if(helprequested){
 400                 printf("\n%s\n", BTRFS_BUILD_VERSION);
 401                 return 0;
 402         }
 403
 404         if(!matchcmd){
 405                 fprintf( stderr, "ERROR: unknown command '%s'\n",argv[1]);
 406                 help(prgname);
 407                 return -1;
 408         }
 409
 410         if(check_ambiguity(matchcmd, argv))
 411                 return -2;
 412
 413         /* check the number of argument */
 414         if (matchcmd->nargs < 0 && matchcmd->nargs < -*nargs_ ){
 415                 fprintf(stderr, "ERROR: '%s' requires minimum %d arg(s)\n",
 416                         matchcmd->verb, -matchcmd->nargs);
 417                         return -2;
 418         }
 419         if(matchcmd->nargs >= 0 && matchcmd->nargs != *nargs_ && matchcmd->nargs != 999){
 420                 fprintf(stderr, "ERROR: '%s' requires %d arg(s)\n",
 421                         matchcmd->verb, matchcmd->nargs);
 422                         return -2;
 423         }
 424
 425         if (prepare_args( nargs_, args_, prgname, matchcmd )){
 426                 fprintf(stderr, "ERROR: not enough memory\\n");
 427                 return -20;
 428         }
 429
 430
 431         return 1;
 432 }
 433 int main(int ac, char **av )
 434 {
 435
 436         char            *cmd=0, **args=0;
 437         int             nargs=0, r;
 438         CommandFunction func=0;
 439
 440         r = parse_args(ac, av, &func, &nargs, &cmd, &args);
 441         if( r <= 0 ){
 442                 /* error or no command to parse*/
 443                 exit(-r);
 444         }
 445
 446         exit(func(nargs, args));
 447
 448 }
 449