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