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_scan, 999,
 131           "device scan", "[<device>...]\n"
 132                 "Scan all device for or the passed device for a btrfs\n"
 133                 "filesystem.",
 134           NULL
 135         },
 136         { do_add_volume, -2,
 137           "device add", "<device> [<device>...] <path>\n"
 138                 "Add a device to a filesystem.",
 139           NULL
 140         },
 141         { do_remove_volume, -2,
 142           "device delete", "<device> [<device>...] <path>\n"
 143                 "Remove a device from a filesystem.",
 144           NULL
 145         },
 146         { 0, 0, 0, 0 }
 147 };
 148
 149 static char *get_prgname(char *programname)
 150 {
 151         char    *np;
 152         np = strrchr(programname,'/');
 153         if(!np)
 154                 np = programname;
 155         else
 156                 np++;
 157
 158         return np;
 159 }
 160
 161 static void print_help(char *programname, struct Command *cmd, int helptype)
 162 {
 163         char    *pc;
 164
 165         printf("\t%s %s ", programname, cmd->verb );
 166
 167         if (helptype == ADVANCED_HELP && cmd->adv_help)
 168                 for(pc = cmd->adv_help; *pc; pc++){
 169                         putchar(*pc);
 170                         if(*pc == '\n')
 171                                 printf("\t\t");
 172                 }
 173         else
 174                 for(pc = cmd->help; *pc; pc++){
 175                         putchar(*pc);
 176                         if(*pc == '\n')
 177                                 printf("\t\t");
 178                 }
 179
 180         putchar('\n');
 181 }
 182
 183 static void help(char *np)
 184 {
 185         struct Command *cp;
 186
 187         printf("Usage:\n");
 188         for( cp = commands; cp->verb; cp++ )
 189                 print_help(np, cp, BASIC_HELP);
 190
 191         printf("\n\t%s help|--help|-h\n\t\tShow the help.\n",np);
 192         printf("\n\t%s <cmd> --help\n\t\tShow detailed help for a command or\n\t\t"
 193                "subset of commands.\n",np);
 194         printf("\n%s\n", BTRFS_BUILD_VERSION);
 195 }
 196
 197 static int split_command(char *cmd, char ***commands)
 198 {
 199         int     c, l;
 200         char    *p, *s;
 201
 202         for( *commands = 0, l = c = 0, p = s = cmd ; ; p++, l++ ){
 203                 if ( *p && *p != ' ' )
 204                         continue;
 205
 206                 /* c + 2 so that we have room for the null */
 207                 (*commands) = realloc( (*commands), sizeof(char *)*(c + 2));
 208                 (*commands)[c] = strndup(s, l);
 209                 c++;
 210                 l = 0;
 211                 s = p+1;
 212                 if( !*p ) break;
 213         }
 214
 215         (*commands)[c] = 0;
 216         return c;
 217 }
 218
 219 /*
 220         This function checks if the passed command is ambiguous
 221 */
 222 static int check_ambiguity(struct Command *cmd, char **argv){
 223         int             i;
 224         struct Command  *cp;
 225         /* check for ambiguity */
 226         for( i = 0 ; i < cmd->ncmds ; i++ ){
 227                 int match;
 228                 for( match = 0, cp = commands; cp->verb; cp++ ){
 229                         int     j, skip;
 230                         char    *s1, *s2;
 231
 232                         if( cp->ncmds < i )
 233                                 continue;
 234
 235                         for( skip = 0, j = 0 ; j < i ; j++ )
 236                                 if( strcmp(cmd->cmds[j], cp->cmds[j])){
 237                                         skip=1;
 238                                         break;
 239                                 }
 240                         if(skip)
 241                                 continue;
 242
 243                         if( !strcmp(cmd->cmds[i], cp->cmds[i]))
 244                                 continue;
 245                         for(s2 = cp->cmds[i], s1 = argv[i+1];
 246                                 *s1 == *s2 && *s1; s1++, s2++ ) ;
 247                         if( !*s1 )
 248                                 match++;
 249                 }
 250                 if(match){
 251                         int j;
 252                         fprintf(stderr, "ERROR: in command '");
 253                         for( j = 0 ; j <= i ; j++ )
 254                                 fprintf(stderr, "%s%s",j?" ":"", argv[j+1]);
 255                         fprintf(stderr, "', '%s' is ambiguous\n",argv[j]);
 256                         return -2;
 257                 }
 258         }
 259         return 0;
 260 }
 261
 262 /*
 263  * This function, compacts the program name and the command in the first
 264  * element of the '*av' array
 265  */
 266 static int prepare_args(int *ac, char ***av, char *prgname, struct Command *cmd ){
 267
 268         char    **ret;
 269         int     i;
 270         char    *newname;
 271
 272         ret = (char **)malloc(sizeof(char*)*(*ac+1));
 273         newname = (char*)malloc(strlen(prgname)+strlen(cmd->verb)+2);
 274         if( !ret || !newname ){
 275                 free(ret);
 276                 free(newname);
 277                 return -1;
 278         }
 279
 280         ret[0] = newname;
 281         for(i=0; i < *ac ; i++ )
 282                 ret[i+1] = (*av)[i];
 283
 284         strcpy(newname, prgname);
 285         strcat(newname, " ");
 286         strcat(newname, cmd->verb);
 287
 288         (*ac)++;
 289         *av = ret;
 290
 291         return 0;
 292
 293 }
 294
 295
 296
 297 /*
 298         This function performs the following jobs:
 299         - show the help if '--help' or 'help' or '-h' are passed
 300         - verify that a command is not ambiguous, otherwise show which
 301           part of the command is ambiguous
 302         - if after a (even partial) command there is '--help' show detailed help
 303           for all the matching commands
 304         - if the command doesn't match show an error
 305         - finally, if a command matches, they return which command matched and
 306           the arguments
 307
 308         The function return 0 in case of help is requested; <0 in case
 309         of uncorrect command; >0 in case of matching commands
 310         argc, argv are the arg-counter and arg-vector (input)
 311         *nargs_ is the number of the arguments after the command (output)
 312         **cmd_  is the invoked command (output)
 313         ***args_ are the arguments after the command
 314
 315 */
 316 static int parse_args(int argc, char **argv,
 317                       CommandFunction *func_,
 318                       int *nargs_, char **cmd_, char ***args_ )
 319 {
 320         struct Command  *cp;
 321         struct Command  *matchcmd=0;
 322         char            *prgname = get_prgname(argv[0]);
 323         int             i=0, helprequested=0;
 324
 325         if( argc < 2 || !strcmp(argv[1], "help") ||
 326                 !strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")){
 327                 help(prgname);
 328                 return 0;
 329         }
 330
 331         for( cp = commands; cp->verb; cp++ )
 332                 if( !cp->ncmds)
 333                         cp->ncmds = split_command(cp->verb, &(cp->cmds));
 334
 335         for( cp = commands; cp->verb; cp++ ){
 336                 int     match;
 337
 338                 if( argc-1 < cp->ncmds )
 339                         continue;
 340                 for( match = 1, i = 0 ; i < cp->ncmds ; i++ ){
 341                         char    *s1, *s2;
 342                         s1 = cp->cmds[i];
 343                         s2 = argv[i+1];
 344
 345                         for(s2 = cp->cmds[i], s1 = argv[i+1];
 346                                 *s1 == *s2 && *s1;
 347                                 s1++, s2++ ) ;
 348                         if( *s1 ){
 349                                 match=0;
 350                                 break;
 351                         }
 352                 }
 353
 354                 /* If you understand why this code works ...
 355                         you are a genious !! */
 356                 if(argc>i+1 && !strcmp(argv[i+1],"--help")){
 357                         if(!helprequested)
 358                                 printf("Usage:\n");
 359                         print_help(prgname, cp, ADVANCED_HELP);
 360                         helprequested=1;
 361                         continue;
 362                 }
 363
 364                 if(!match)
 365                         continue;
 366
 367                 matchcmd = cp;
 368                 *nargs_  = argc-matchcmd->ncmds-1;
 369                 *cmd_ = matchcmd->verb;
 370                 *args_ = argv+matchcmd->ncmds+1;
 371                 *func_ = cp->func;
 372
 373                 break;
 374         }
 375
 376         if(helprequested){
 377                 printf("\n%s\n", BTRFS_BUILD_VERSION);
 378                 return 0;
 379         }
 380
 381         if(!matchcmd){
 382                 fprintf( stderr, "ERROR: unknown command '%s'\n",argv[1]);
 383                 help(prgname);
 384                 return -1;
 385         }
 386
 387         if(check_ambiguity(matchcmd, argv))
 388                 return -2;
 389
 390         /* check the number of argument */
 391         if (matchcmd->nargs < 0 && matchcmd->nargs < -*nargs_ ){
 392                 fprintf(stderr, "ERROR: '%s' requires minimum %d arg(s)\n",
 393                         matchcmd->verb, -matchcmd->nargs);
 394                         return -2;
 395         }
 396         if(matchcmd->nargs >= 0 && matchcmd->nargs != *nargs_ && matchcmd->nargs != 999){
 397                 fprintf(stderr, "ERROR: '%s' requires %d arg(s)\n",
 398                         matchcmd->verb, matchcmd->nargs);
 399                         return -2;
 400         }
 401
 402         if (prepare_args( nargs_, args_, prgname, matchcmd )){
 403                 fprintf(stderr, "ERROR: not enough memory\\n");
 404                 return -20;
 405         }
 406
 407
 408         return 1;
 409 }
 410 int main(int ac, char **av )
 411 {
 412
 413         char            *cmd=0, **args=0;
 414         int             nargs=0, r;
 415         CommandFunction func=0;
 416
 417         r = parse_args(ac, av, &func, &nargs, &cmd, &args);
 418         if( r <= 0 ){
 419                 /* error or no command to parse*/
 420                 exit(-r);
 421         }
 422
 423         exit(func(nargs, args));
 424
 425 }
 426