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
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21
  22 #include "btrfs_cmds.h"
  23 #include "version.h"
  24
  25 typedef int (*CommandFunction)(int argc, char **argv);
  26
  27 struct Command {
  28         CommandFunction func;   /* function which implements the command */
  29         int     nargs;          /* if == 999, any number of arguments
  30                                    if >= 0, number of arguments,
  31                                    if < 0, _minimum_ number of arguments */
  32         char    *verb;          /* verb */
  33         char    *help;          /* help lines; form the 2nd onward they are
  34                                    indented */
  35
  36         /* the following fields are run-time filled by the program */
  37         char    **cmds;         /* array of subcommands */
  38         int     ncmds;          /* number of subcommand */
  39 };
  40
  41 static struct Command commands[] = {
  42
  43         /*
  44                 avoid short commands different for the case only
  45         */
  46         { do_clone, 2,
  47           "subvolume snapshot", "<source> [<dest>/]<name>\n"
  48                 "Create a writable snapshot of the subvolume <source> with\n"
  49                 "the name <name> in the <dest> directory."
  50         },
  51         { do_delete_subvolume, 1,
  52           "subvolume delete", "<subvolume>\n"
  53                 "Delete the subvolume <subvolume>."
  54         },
  55         { do_create_subvol, 1,
  56           "subvolume create", "[<dest>/]<name>\n"
  57                 "Create a subvolume in <dest> (or the current directory if\n"
  58                 "not passed)."
  59         },
  60         { do_subvol_list, 1, "subvolume list", "<path>\n"
  61                 "List the snapshot/subvolume of a filesystem."
  62         },
  63
  64         { do_defrag, -1,
  65           "filesystem defragment", "[-vcf] [-s start] [-l len] [-t size] <file>|<dir> [<file>|<dir>...]\n"
  66                 "Defragment a file or a directory."
  67         },
  68         { do_fssync, 1,
  69           "filesystem sync", "<path>\n"
  70                 "Force a sync on the filesystem <path>."
  71         },
  72         { do_resize, 2,
  73           "filesystem resize", "[+/-]<newsize>[gkm]|max <filesystem>\n"
  74                 "Resize the file system. If 'max' is passed, the filesystem\n"
  75                 "will occupe all available space on the device."
  76         },
  77         { do_show_filesystem, 999,
  78           "filesystem show", "[<uuid>|<label>]\n"
  79                 "Show the info of a btrfs filesystem. If no <uuid> or <label>\n"
  80                 "is passed, info of all the btrfs filesystem are shown."
  81         },
  82         { do_balance, 1,
  83           "filesystem balance", "<path>\n"
  84                 "Balance the chunks across the device."
  85         },
  86         { do_scan,
  87           999, "device scan", "[<device> [<device>..]\n"
  88                 "Scan all device for or the passed device for a btrfs\n"
  89                 "filesystem."
  90         },
  91         { do_add_volume, -1,
  92           "device add", "<dev> [<dev>..] <path>\n"
  93                 "Add a device to a filesystem."
  94         },
  95         { do_remove_volume, -1,
  96           "device delete", "<dev> [<dev>..] <path>\n"
  97                 "Remove a device from a filesystem."
  98         },
  99         /* coming soon
 100         { 2, "filesystem label", "<label> <path>\n"
 101                 "Set the label of a filesystem"
 102         }
 103         */
 104         { 0, 0 , 0 }
 105 };
 106
 107
 108
 109
 110 static char *get_prgname(char *programname)
 111 {
 112         char    *np;
 113         np = strrchr(programname,'/');
 114         if(!np)
 115                 np = programname;
 116         else
 117                 np++;
 118
 119         return np;
 120 }
 121
 122 static void print_help(char *programname, struct Command *cmd)
 123 {
 124         char    *pc;
 125
 126         printf("\t%s %s ", programname, cmd->verb );
 127
 128         for(pc = cmd->help; *pc; pc++){
 129                 putchar(*pc);
 130                 if(*pc == '\n')
 131                         printf("\t\t");
 132         }
 133         putchar('\n');
 134 }
 135
 136 static void help(char *np)
 137 {
 138         struct Command *cp;
 139
 140         printf("Usage:\n");
 141         for( cp = commands; cp->verb; cp++ )
 142                 print_help(np, cp);
 143
 144         printf("\n\t%s help|--help|-h\n\t\tShow the help.\n",np);
 145         printf("\n%s\n", BTRFS_BUILD_VERSION);
 146 }
 147
 148 static int split_command(char *cmd, char ***commands)
 149 {
 150         int     c, l;
 151         char    *p, *s;
 152
 153         for( *commands = 0, l = c = 0, p = s = cmd ; ; p++, l++ ){
 154                 if ( *p && *p != ' ' )
 155                         continue;
 156
 157                 /* c + 2 so that we have room for the null */
 158                 (*commands) = realloc( (*commands), sizeof(char *)*(c + 2));
 159                 (*commands)[c] = strndup(s, l);
 160                 c++;
 161                 l = 0;
 162                 s = p+1;
 163                 if( !*p ) break;
 164         }
 165
 166         (*commands)[c] = 0;
 167         return c;
 168 }
 169
 170 /*
 171         This function checks if the passed command is ambiguous
 172 */
 173 static int check_ambiguity(struct Command *cmd, char **argv){
 174         int             i;
 175         struct Command  *cp;
 176         /* check for ambiguity */
 177         for( i = 0 ; i < cmd->ncmds ; i++ ){
 178                 int match;
 179                 for( match = 0, cp = commands; cp->verb; cp++ ){
 180                         int     j, skip;
 181                         char    *s1, *s2;
 182
 183                         if( cp->ncmds < i )
 184                                 continue;
 185
 186                         for( skip = 0, j = 0 ; j < i ; j++ )
 187                                 if( strcmp(cmd->cmds[j], cp->cmds[j])){
 188                                         skip=1;
 189                                         break;
 190                                 }
 191                         if(skip)
 192                                 continue;
 193
 194                         if( !strcmp(cmd->cmds[i], cp->cmds[i]))
 195                                 continue;
 196                         for(s2 = cp->cmds[i], s1 = argv[i+1];
 197                                 *s1 == *s2 && *s1; s1++, s2++ ) ;
 198                         if( !*s1 )
 199                                 match++;
 200                 }
 201                 if(match){
 202                         int j;
 203                         fprintf(stderr, "ERROR: in command '");
 204                         for( j = 0 ; j <= i ; j++ )
 205                                 fprintf(stderr, "%s%s",j?" ":"", argv[j+1]);
 206                         fprintf(stderr, "', '%s' is ambiguous\n",argv[j]);
 207                         return -2;
 208                 }
 209         }
 210         return 0;
 211 }
 212
 213 /*
 214  * This function, compacts the program name and the command in the first
 215  * element of the '*av' array
 216  */
 217 static int prepare_args(int *ac, char ***av, char *prgname, struct Command *cmd ){
 218
 219         char    **ret;
 220         int     i;
 221         char    *newname;
 222
 223         ret = (char **)malloc(sizeof(char*)*(*ac+1));
 224         newname = (char*)malloc(strlen(prgname)+strlen(cmd->verb)+2);
 225         if( !ret || !newname ){
 226                 free(ret);
 227                 free(newname);
 228                 return -1;
 229         }
 230
 231         ret[0] = newname;
 232         for(i=0; i < *ac ; i++ )
 233                 ret[i+1] = (*av)[i];
 234
 235         strcpy(newname, prgname);
 236         strcat(newname, " ");
 237         strcat(newname, cmd->verb);
 238
 239         (*ac)++;
 240         *av = ret;
 241
 242         return 0;
 243
 244 }
 245
 246
 247
 248 /*
 249
 250         This function perform the following jobs:
 251         - show the help if '--help' or 'help' or '-h' are passed
 252         - verify that a command is not ambiguous, otherwise show which
 253           part of the command is ambiguous
 254         - if after a (even partial) command there is '--help' show the help
 255           for all the matching commands
 256         - if the command doesn't' match show an error
 257         - finally, if a command match, they return which command is matched and
 258           the arguments
 259
 260         The function return 0 in case of help is requested; <0 in case
 261         of uncorrect command; >0 in case of matching commands
 262         argc, argv are the arg-counter and arg-vector (input)
 263         *nargs_ is the number of the arguments after the command (output)
 264         **cmd_  is the invoked command (output)
 265         ***args_ are the arguments after the command
 266
 267 */
 268 static int parse_args(int argc, char **argv,
 269                       CommandFunction *func_,
 270                       int *nargs_, char **cmd_, char ***args_ )
 271 {
 272         struct Command  *cp;
 273         struct Command  *matchcmd=0;
 274         char            *prgname = get_prgname(argv[0]);
 275         int             i=0, helprequested=0;
 276
 277         if( argc < 2 || !strcmp(argv[1], "help") ||
 278                 !strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")){
 279                 help(prgname);
 280                 return 0;
 281         }
 282
 283         for( cp = commands; cp->verb; cp++ )
 284                 if( !cp->ncmds)
 285                         cp->ncmds = split_command(cp->verb, &(cp->cmds));
 286
 287         for( cp = commands; cp->verb; cp++ ){
 288                 int     match;
 289
 290                 if( argc-1 < cp->ncmds )
 291                         continue;
 292                 for( match = 1, i = 0 ; i < cp->ncmds ; i++ ){
 293                         char    *s1, *s2;
 294                         s1 = cp->cmds[i];
 295                         s2 = argv[i+1];
 296
 297                         for(s2 = cp->cmds[i], s1 = argv[i+1];
 298                                 *s1 == *s2 && *s1;
 299                                 s1++, s2++ ) ;
 300                         if( *s1 ){
 301                                 match=0;
 302                                 break;
 303                         }
 304                 }
 305
 306                 /* If you understand why this code works ...
 307                         you are a genious !! */
 308                 if(argc>i+1 && !strcmp(argv[i+1],"--help")){
 309                         if(!helprequested)
 310                                 printf("Usage:\n");
 311                         print_help(prgname, cp);
 312                         helprequested=1;
 313                         continue;
 314                 }
 315
 316                 if(!match)
 317                         continue;
 318
 319                 matchcmd = cp;
 320                 *nargs_  = argc-matchcmd->ncmds-1;
 321                 *cmd_ = matchcmd->verb;
 322                 *args_ = argv+matchcmd->ncmds+1;
 323                 *func_ = cp->func;
 324
 325                 break;
 326         }
 327
 328         if(helprequested){
 329                 printf("\n%s\n", BTRFS_BUILD_VERSION);
 330                 return 0;
 331         }
 332
 333         if(!matchcmd){
 334                 fprintf( stderr, "ERROR: unknown command '%s'\n",argv[1]);
 335                 help(prgname);
 336                 return -1;
 337         }
 338
 339         if(check_ambiguity(matchcmd, argv))
 340                 return -2;
 341
 342         /* check the number of argument */
 343         if (matchcmd->nargs < 0 && matchcmd->nargs < -*nargs_ ){
 344                 fprintf(stderr, "ERROR: '%s' requires minimum %d arg(s)\n",
 345                         matchcmd->verb, -matchcmd->nargs);
 346                         return -2;
 347         }
 348         if(matchcmd->nargs >= 0 && matchcmd->nargs != *nargs_ && matchcmd->nargs != 999){
 349                 fprintf(stderr, "ERROR: '%s' requires %d arg(s)\n",
 350                         matchcmd->verb, matchcmd->nargs);
 351                         return -2;
 352         }
 353
 354         if (prepare_args( nargs_, args_, prgname, matchcmd )){
 355                 fprintf(stderr, "ERROR: not enough memory\\n");
 356                 return -20;
 357         }
 358
 359
 360         return 1;
 361 }
 362 int main(int ac, char **av )
 363 {
 364
 365         char            *cmd=0, **args=0;
 366         int             nargs=0, r;
 367         CommandFunction func=0;
 368
 369         r = parse_args(ac, av, &func, &nargs, &cmd, &args);
 370         if( r <= 0 ){
 371                 /* error or no command to parse*/
 372                 exit(-r);
 373         }
 374
 375         exit(func(nargs, args));
 376
 377 }
 378