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", "<source> [<dest>/]<name>\n"
  54                 "Create a writable 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", "<path>\n"
  70                 "List the snapshot/subvolume of a filesystem.",
  71           NULL
  72         },
  73         { do_set_default_subvol, 2,
  74           "subvolume set-default", "<id> <path>\n"
  75                 "Set the subvolume of the filesystem <path> which will be mounted\n"
  76                 "as default.",
  77           NULL
  78         },
  79         { do_find_newer, 2, "subvolume find-new", "<path> <last_gen>\n"
  80                 "List the recently modified files in a filesystem.",
  81           NULL
  82         },
  83         { do_defrag, -1,
  84           "filesystem defragment", "[-vf] [-c[zlib,lzo]] [-s start] [-l len] [-t size] <file>|<dir> [<file>|<dir>...]\n"
  85                 "Defragment a file or a directory.",
  86                 "[-vcf] [-s start] [-l len] [-t size] <file>|<dir> [<file>|<dir>...]\n"
  87                 "Defragment file data or directory metadata.\n"
  88                 "-v         be verbose\n"
  89                 "-c         compress the file while defragmenting\n"
  90                 "-f         flush data to disk immediately after defragmenting\n"
  91                 "-s start   defragment only from byte onward\n"
  92                 "-l len     defragment only up to len bytes\n"
  93                 "-t size    minimal size of file to be considered for defragmenting\n"
  94         },
  95         { do_fssync, 1,
  96           "filesystem sync", "<path>\n"
  97                 "Force a sync on the filesystem <path>.",
  98           NULL
  99         },
 100         { do_resize, 2,
 101           "filesystem resize", "[+/-]<newsize>[gkm]|max <filesystem>\n"
 102                 "Resize the file system. If 'max' is passed, the filesystem\n"
 103                 "will occupe all available space on the device.",
 104           NULL
 105         },
 106         { do_show_filesystem, 999,
 107           "filesystem show", "[<device>|<uuid>|<label>]\n"
 108                 "Show the info of a btrfs filesystem. If no argument\n"
 109                 "is passed, info of all the btrfs filesystem are shown.",
 110           NULL
 111         },
 112         { do_df_filesystem, 1,
 113           "filesystem df", "<path>\n"
 114                 "Show space usage information for a mount point.",
 115           NULL
 116         },
 117         { do_balance, 1,
 118           "filesystem balance", "<path>\n"
 119                 "Balance the chunks across the device.",
 120           NULL
 121         },
 122         { do_scan, 999,
 123           "device scan", "[<device>...]\n"
 124                 "Scan all device for or the passed device for a btrfs\n"
 125                 "filesystem.",
 126           NULL
 127         },
 128         { do_add_volume, -2,
 129           "device add", "<device> [<device>...] <path>\n"
 130                 "Add a device to a filesystem.",
 131           NULL
 132         },
 133         { do_remove_volume, -2,
 134           "device delete", "<device> [<device>...] <path>\n"
 135                 "Remove a device from a filesystem.",
 136           NULL
 137         },
 138         { 0, 0, 0, 0 }
 139 };
 140
 141 static char *get_prgname(char *programname)
 142 {
 143         char    *np;
 144         np = strrchr(programname,'/');
 145         if(!np)
 146                 np = programname;
 147         else
 148                 np++;
 149
 150         return np;
 151 }
 152
 153 static void print_help(char *programname, struct Command *cmd, int helptype)
 154 {
 155         char    *pc;
 156
 157         printf("\t%s %s ", programname, cmd->verb );
 158
 159         if (helptype == ADVANCED_HELP && cmd->adv_help)
 160                 for(pc = cmd->adv_help; *pc; pc++){
 161                         putchar(*pc);
 162                         if(*pc == '\n')
 163                                 printf("\t\t");
 164                 }
 165         else
 166                 for(pc = cmd->help; *pc; pc++){
 167                         putchar(*pc);
 168                         if(*pc == '\n')
 169                                 printf("\t\t");
 170                 }
 171
 172         putchar('\n');
 173 }
 174
 175 static void help(char *np)
 176 {
 177         struct Command *cp;
 178
 179         printf("Usage:\n");
 180         for( cp = commands; cp->verb; cp++ )
 181                 print_help(np, cp, BASIC_HELP);
 182
 183         printf("\n\t%s help|--help|-h\n\t\tShow the help.\n",np);
 184         printf("\n\t%s <cmd> --help\n\t\tShow detailed help for a command or\n\t\t"
 185                "subset of commands.\n",np);
 186         printf("\n%s\n", BTRFS_BUILD_VERSION);
 187 }
 188
 189 static int split_command(char *cmd, char ***commands)
 190 {
 191         int     c, l;
 192         char    *p, *s;
 193
 194         for( *commands = 0, l = c = 0, p = s = cmd ; ; p++, l++ ){
 195                 if ( *p && *p != ' ' )
 196                         continue;
 197
 198                 /* c + 2 so that we have room for the null */
 199                 (*commands) = realloc( (*commands), sizeof(char *)*(c + 2));
 200                 (*commands)[c] = strndup(s, l);
 201                 c++;
 202                 l = 0;
 203                 s = p+1;
 204                 if( !*p ) break;
 205         }
 206
 207         (*commands)[c] = 0;
 208         return c;
 209 }
 210
 211 /*
 212         This function checks if the passed command is ambiguous
 213 */
 214 static int check_ambiguity(struct Command *cmd, char **argv){
 215         int             i;
 216         struct Command  *cp;
 217         /* check for ambiguity */
 218         for( i = 0 ; i < cmd->ncmds ; i++ ){
 219                 int match;
 220                 for( match = 0, cp = commands; cp->verb; cp++ ){
 221                         int     j, skip;
 222                         char    *s1, *s2;
 223
 224                         if( cp->ncmds < i )
 225                                 continue;
 226
 227                         for( skip = 0, j = 0 ; j < i ; j++ )
 228                                 if( strcmp(cmd->cmds[j], cp->cmds[j])){
 229                                         skip=1;
 230                                         break;
 231                                 }
 232                         if(skip)
 233                                 continue;
 234
 235                         if( !strcmp(cmd->cmds[i], cp->cmds[i]))
 236                                 continue;
 237                         for(s2 = cp->cmds[i], s1 = argv[i+1];
 238                                 *s1 == *s2 && *s1; s1++, s2++ ) ;
 239                         if( !*s1 )
 240                                 match++;
 241                 }
 242                 if(match){
 243                         int j;
 244                         fprintf(stderr, "ERROR: in command '");
 245                         for( j = 0 ; j <= i ; j++ )
 246                                 fprintf(stderr, "%s%s",j?" ":"", argv[j+1]);
 247                         fprintf(stderr, "', '%s' is ambiguous\n",argv[j]);
 248                         return -2;
 249                 }
 250         }
 251         return 0;
 252 }
 253
 254 /*
 255  * This function, compacts the program name and the command in the first
 256  * element of the '*av' array
 257  */
 258 static int prepare_args(int *ac, char ***av, char *prgname, struct Command *cmd ){
 259
 260         char    **ret;
 261         int     i;
 262         char    *newname;
 263
 264         ret = (char **)malloc(sizeof(char*)*(*ac+1));
 265         newname = (char*)malloc(strlen(prgname)+strlen(cmd->verb)+2);
 266         if( !ret || !newname ){
 267                 free(ret);
 268                 free(newname);
 269                 return -1;
 270         }
 271
 272         ret[0] = newname;
 273         for(i=0; i < *ac ; i++ )
 274                 ret[i+1] = (*av)[i];
 275
 276         strcpy(newname, prgname);
 277         strcat(newname, " ");
 278         strcat(newname, cmd->verb);
 279
 280         (*ac)++;
 281         *av = ret;
 282
 283         return 0;
 284
 285 }
 286
 287
 288
 289 /*
 290         This function performs the following jobs:
 291         - show the help if '--help' or 'help' or '-h' are passed
 292         - verify that a command is not ambiguous, otherwise show which
 293           part of the command is ambiguous
 294         - if after a (even partial) command there is '--help' show detailed help
 295           for all the matching commands
 296         - if the command doesn't match show an error
 297         - finally, if a command matches, they return which command matched and
 298           the arguments
 299
 300         The function return 0 in case of help is requested; <0 in case
 301         of uncorrect command; >0 in case of matching commands
 302         argc, argv are the arg-counter and arg-vector (input)
 303         *nargs_ is the number of the arguments after the command (output)
 304         **cmd_  is the invoked command (output)
 305         ***args_ are the arguments after the command
 306
 307 */
 308 static int parse_args(int argc, char **argv,
 309                       CommandFunction *func_,
 310                       int *nargs_, char **cmd_, char ***args_ )
 311 {
 312         struct Command  *cp;
 313         struct Command  *matchcmd=0;
 314         char            *prgname = get_prgname(argv[0]);
 315         int             i=0, helprequested=0;
 316
 317         if( argc < 2 || !strcmp(argv[1], "help") ||
 318                 !strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")){
 319                 help(prgname);
 320                 return 0;
 321         }
 322
 323         for( cp = commands; cp->verb; cp++ )
 324                 if( !cp->ncmds)
 325                         cp->ncmds = split_command(cp->verb, &(cp->cmds));
 326
 327         for( cp = commands; cp->verb; cp++ ){
 328                 int     match;
 329
 330                 if( argc-1 < cp->ncmds )
 331                         continue;
 332                 for( match = 1, i = 0 ; i < cp->ncmds ; i++ ){
 333                         char    *s1, *s2;
 334                         s1 = cp->cmds[i];
 335                         s2 = argv[i+1];
 336
 337                         for(s2 = cp->cmds[i], s1 = argv[i+1];
 338                                 *s1 == *s2 && *s1;
 339                                 s1++, s2++ ) ;
 340                         if( *s1 ){
 341                                 match=0;
 342                                 break;
 343                         }
 344                 }
 345
 346                 /* If you understand why this code works ...
 347                         you are a genious !! */
 348                 if(argc>i+1 && !strcmp(argv[i+1],"--help")){
 349                         if(!helprequested)
 350                                 printf("Usage:\n");
 351                         print_help(prgname, cp, ADVANCED_HELP);
 352                         helprequested=1;
 353                         continue;
 354                 }
 355
 356                 if(!match)
 357                         continue;
 358
 359                 matchcmd = cp;
 360                 *nargs_  = argc-matchcmd->ncmds-1;
 361                 *cmd_ = matchcmd->verb;
 362                 *args_ = argv+matchcmd->ncmds+1;
 363                 *func_ = cp->func;
 364
 365                 break;
 366         }
 367
 368         if(helprequested){
 369                 printf("\n%s\n", BTRFS_BUILD_VERSION);
 370                 return 0;
 371         }
 372
 373         if(!matchcmd){
 374                 fprintf( stderr, "ERROR: unknown command '%s'\n",argv[1]);
 375                 help(prgname);
 376                 return -1;
 377         }
 378
 379         if(check_ambiguity(matchcmd, argv))
 380                 return -2;
 381
 382         /* check the number of argument */
 383         if (matchcmd->nargs < 0 && matchcmd->nargs < -*nargs_ ){
 384                 fprintf(stderr, "ERROR: '%s' requires minimum %d arg(s)\n",
 385                         matchcmd->verb, -matchcmd->nargs);
 386                         return -2;
 387         }
 388         if(matchcmd->nargs >= 0 && matchcmd->nargs != *nargs_ && matchcmd->nargs != 999){
 389                 fprintf(stderr, "ERROR: '%s' requires %d arg(s)\n",
 390                         matchcmd->verb, matchcmd->nargs);
 391                         return -2;
 392         }
 393
 394         if (prepare_args( nargs_, args_, prgname, matchcmd )){
 395                 fprintf(stderr, "ERROR: not enough memory\\n");
 396                 return -20;
 397         }
 398
 399
 400         return 1;
 401 }
 402 int main(int ac, char **av )
 403 {
 404
 405         char            *cmd=0, **args=0;
 406         int             nargs=0, r;
 407         CommandFunction func=0;
 408
 409         r = parse_args(ac, av, &func, &nargs, &cmd, &args);
 410         if( r <= 0 ){
 411                 /* error or no command to parse*/
 412                 exit(-r);
 413         }
 414
 415         exit(func(nargs, args));
 416
 417 }
 418