partx/partx.c

   1 /*
   2  * Given a block device and a partition table type,
   3  * try to parse the partition table, and list the
   4  * contents. Optionally add or remove partitions.
   5  *
   6  * [This is not an fdisk - adding and removing partitions
   7  * is not a change of the disk, but just telling the kernel
   8  * about presence and numbering of on-disk partitions.]
   9  *
  10  * Call:
  11  *      partx [-{l|a|d}] [--type TYPE] [--nr M-N] [partition] wholedisk
  12  * where TYPE is {dos|bsd|solaris|unixware|gpt}.
  13  *
  14  * Read wholedisk and add all partitions:
  15  *      partx -a wholedisk
  16  *
  17  * Subdivide a partition into slices (and delete or shrink the partition):
  18  * [Not easy: one needs the partition number of partition -
  19  *  that is the last 4 or 6 bits of the minor; it can also be found
  20  *  in /proc/partitions; but there is no good direct way.]
  21  *      partx -a partition wholedisk
  22  *
  23  * Delete all partitions from wholedisk:
  24  *      partx -d wholedisk
  25  *
  26  * Delete partitions M-N from wholedisk:
  27  *      partx -d --nr M-N wholedisk
  28  *
  29  * aeb, 2000-03-21 -- sah is 42 now
  30  */
  31
  32 #include <stdio.h>
  33 #include <fcntl.h>
  34 #include <errno.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <getopt.h>
  38 #include <unistd.h>
  39 #include <sys/ioctl.h>
  40 #include <linux/hdreg.h>        /* HDIO_GETGEO */
  41 #ifdef HAVE_LINUX_COMPILER_H
  42 #include <linux/compiler.h>
  43 #endif
  44 #include <linux/blkpg.h>
  45 #define BLKGETSIZE _IO(0x12,96)    /* return device size */
  46
  47 #include "partx.h"
  48 #include "crc32.h"
  49 static void errmerge(int err, int m, char *msg1, char *msg2);
  50
  51 #define SIZE(a) (sizeof(a)/sizeof((a)[0]))
  52
  53 #define MAXTYPES        64
  54 #define MAXSLICES       256
  55
  56 struct slice slices[MAXSLICES];
  57
  58 enum action { LIST, ADD, DELETE };
  59
  60 struct pt {
  61         char *type;
  62         ptreader *fn;
  63 } pts[MAXTYPES];
  64 int ptct;
  65
  66 static void
  67 addpts(char *t, ptreader f)
  68 {
  69         if (ptct >= MAXTYPES) {
  70                 fprintf(stderr, "addpts: too many types\n");
  71                 exit(1);
  72         }
  73         pts[ptct].type = t;
  74         pts[ptct].fn = f;
  75         ptct++;
  76 }
  77
  78 static void
  79 initpts(void)
  80 {
  81         addpts("gpt", read_gpt_pt);
  82         addpts("dos", read_dos_pt);
  83         addpts("bsd", read_bsd_pt);
  84         addpts("solaris", read_solaris_pt);
  85         addpts("unixware", read_unixware_pt);
  86 }
  87
  88 static char short_opts[] = "ladgvn:t:";
  89 static const struct option long_opts[] = {
  90         { "gpt",        no_argument,            NULL,   'g' },
  91         { "type",       required_argument,      NULL,   't' },
  92         { "nr",         required_argument,      NULL,   'n' },
  93         { NULL, 0, NULL, 0 }
  94 };
  95
  96 /* Used in gpt.c */
  97 int force_gpt=0;
  98
  99 int
 100 main(int argc, char **argv){
 101         int fd, fd2, c, i, j, k, n;
 102         long size;
 103         struct hd_geometry g;
 104         struct slice all;
 105         struct blkpg_ioctl_arg a;
 106         struct blkpg_partition pt;
 107         struct pt *ptp;
 108         enum action what = LIST;
 109         char *p, *type, *diskdevice, *device;
 110         int lower, upper;
 111         int verbose = 0;
 112         int ret = 0;
 113
 114         initpts();
 115         init_crc32();
 116
 117         lower = upper = 0;
 118         type = device = diskdevice = NULL;
 119
 120         while ((c = getopt_long (argc, argv, short_opts, long_opts, NULL))
 121                 != -1) switch(c) {
 122         case 'l':
 123                 what = LIST; break;
 124         case 'a':
 125                 what = ADD; break;
 126         case 'd':
 127                 what = DELETE; break;
 128         case 'g':
 129                 force_gpt = 1; break;
 130         case 'n':
 131                 p = optarg;
 132                 lower = atoi(p);
 133                 p = index(p, '-');
 134                 if (p)
 135                         upper = atoi(p+1);
 136                 else
 137                         upper = lower;
 138                 break;
 139         case 't':
 140                 type = optarg;
 141                 break;
 142         case 'v':
 143                 verbose = 1;
 144                 break;
 145         case '?':
 146         default:
 147                 fprintf(stderr, "unknown option\n");
 148                 exit(1);
 149         }
 150
 151         if (optind == argc-2) {
 152                 device = argv[optind];
 153                 diskdevice = argv[optind+1];
 154         } else if (optind == argc-1) {
 155                 diskdevice = device = argv[optind];
 156         } else {
 157                 fprintf(stderr, "call: partx -opts [device] wholedisk\n");
 158                 exit(1);
 159         }
 160
 161         fd = open(diskdevice, O_RDONLY);
 162         if (fd == -1) {
 163                 perror(diskdevice);
 164                 exit(1);
 165         }
 166
 167         /* remove the indicated partitions from the kernel partition tables */
 168         if (what == DELETE) {
 169                 if (device != diskdevice) {
 170                         fprintf(stderr,
 171                                 "call: partx -d [--nr M-N] wholedisk\n");
 172                         exit(1);
 173                 }
 174
 175                 if (!lower)
 176                         lower = 1;
 177
 178                 while (upper == 0 || lower <= upper) {
 179                         int err;
 180
 181                         pt.pno = lower;
 182                         pt.start = 0;
 183                         pt.length = 0;
 184                         pt.devname[0] = 0;
 185                         pt.volname[0] = 0;
 186                         a.op = BLKPG_DEL_PARTITION;
 187                         a.flags = 0;
 188                         a.datalen = sizeof(pt);
 189                         a.data = &pt;
 190                         if (ioctl(fd, BLKPG, &a) == -1)
 191                             err = errno;
 192                         else
 193                             err = 0;
 194                         errmerge(err, lower,
 195                                  "error deleting partition %d: ",
 196                                  "error deleting partitions %d-%d: ");
 197                         /* expected errors:
 198                            EBUSY: mounted or in use as swap
 199                            ENXIO: no such nonempty partition
 200                            EINVAL: not wholedisk, or bad pno
 201                            EACCES/EPERM: permission denied
 202                         */
 203                         if (err && err != EBUSY && err != ENXIO) {
 204                                 ret = 1;
 205                                 break;
 206                         }
 207                         if (err == 0 && verbose)
 208                                 printf("deleted partition %d\n", lower);
 209                         lower++;
 210                 }
 211                 errmerge(0, 0,
 212                          "error deleting partition %d: ",
 213                          "error deleting partitions %d-%d: ");
 214                 return ret;
 215         }
 216
 217         if (device != diskdevice) {
 218                 fd2 = open(device, O_RDONLY);
 219                 if (fd2 == -1) {
 220                         perror(device);
 221                         exit(1);
 222                 }
 223         } else {
 224                 fd2 = fd;
 225         }
 226
 227         if (ioctl(fd, HDIO_GETGEO, &g)) {
 228                 perror("HDIO_GETGEO");
 229                 exit(1);
 230         }
 231         if (g.start != 0) {
 232                 fprintf(stderr, "last arg is not the whole disk\n");
 233                 fprintf(stderr, "call: partx -opts device wholedisk\n");
 234                 exit(1);
 235         }
 236
 237         if (ioctl(fd2, HDIO_GETGEO, &g)) {
 238                 perror("HDIO_GETGEO");
 239                 exit(1);
 240         }
 241         all.start = g.start;
 242
 243         if(ioctl(fd2, BLKGETSIZE, &size)) {
 244                 perror("BLKGETSIZE");
 245                 exit(1);
 246         }
 247         all.size = size;
 248
 249         if (verbose)
 250                 printf("device %s: start %d size %d\n",
 251                        device, all.start, all.size);
 252
 253         if (all.size == 0) {
 254                 fprintf(stderr, "That disk slice has size 0\n");
 255                 exit(0);
 256         }
 257         if (all.size == 2)
 258                 all.size = 0;   /* probably extended partition */
 259
 260         /* add the indicated partitions to the kernel partition tables */
 261         if (!lower)
 262                 lower = 1;
 263         for (i = 0; i < ptct; i++) {
 264                 ptp = &pts[i];
 265                 if (!type || !strcmp(type, ptp->type)) {
 266                         n = ptp->fn(fd, all, slices, SIZE(slices));
 267                         if (n >= 0 && verbose)
 268                             printf("%s: %d slices\n", ptp->type, n);
 269                         if (n > 0 && (verbose || what == LIST)) {
 270                             for (j=0; j<n; j++)
 271                                 printf("#%2d: %9d-%9d (%9d sectors, %6d MB)\n",
 272                                        lower+j,
 273                                        slices[j].start,
 274                                        slices[j].start+slices[j].size-1,
 275                                        slices[j].size,
 276                                        (int)((512 * (long long) slices[j].size)
 277                                         / 1000000));
 278                         }
 279                         if (n > 0 && what == ADD) {
 280                             /* test for overlap, as in the case of an
 281                                extended partition, and reduce size */
 282                             for (j=0; j<n; j++) {
 283                                 for (k=j+1; k<n; k++) {
 284                                     if (slices[k].start > slices[j].start &&
 285                                         slices[k].start < slices[j].start +
 286                                         slices[j].size) {
 287                                             slices[j].size = slices[k].start -
 288                                                 slices[j].start;
 289                                             if (verbose)
 290                                                 printf("reduced size of "
 291                                                        "partition #%d to %d\n",
 292                                                        lower+j,
 293                                                        slices[j].size);
 294                                     }
 295                                 }
 296                             }
 297                             for (j=0; j<n; j++) {
 298                                 pt.pno = lower+j;
 299                                 pt.start = 512 * (long long) slices[j].start;
 300                                 pt.length = 512 * (long long) slices[j].size;
 301                                 pt.devname[0] = 0;
 302                                 pt.volname[0] = 0;
 303                                 a.op = BLKPG_ADD_PARTITION;
 304                                 a.flags = 0;
 305                                 a.datalen = sizeof(pt);
 306                                 a.data = &pt;
 307                                 if (ioctl(fd, BLKPG, &a) == -1) {
 308                                     perror("BLKPG");
 309                                     fprintf(stderr,
 310                                             "error adding partition %d\n",
 311                                             lower+j);
 312                                 } else if (verbose)
 313                                     printf("added partition %d\n", lower+j);
 314                             }
 315                         }
 316                 }
 317         }
 318
 319         return 0;
 320 }
 321
 322 static void *
 323 xmalloc (size_t size) {
 324         void *t;
 325
 326         if (size == 0)
 327                 return NULL;
 328         t = malloc (size);
 329         if (t == NULL) {
 330                 fprintf(stderr, "Out of memory\n");
 331                 exit(1);
 332         }
 333         return t;
 334 }
 335
 336 static int
 337 sseek(int fd, unsigned int secnr) {
 338         long long in, out;
 339         in = ((long long) secnr << 9);
 340         out = 1;
 341
 342         if ((out = lseek(fd, in, SEEK_SET)) != in)
 343         {
 344                 fprintf(stderr, "lseek error\n");
 345                 return -1;
 346         }
 347         return 0;
 348 }
 349
 350 static
 351 struct block {
 352         unsigned int secnr;
 353         char *block;
 354         struct block *next;
 355 } *blockhead;
 356
 357 char *
 358 getblock(int fd, unsigned int secnr) {
 359         struct block *bp;
 360
 361         for (bp = blockhead; bp; bp = bp->next)
 362                 if (bp->secnr == secnr)
 363                         return bp->block;
 364         if (sseek(fd, secnr))
 365                 return NULL;
 366         bp = xmalloc(sizeof(struct block));
 367         bp->secnr = secnr;
 368         bp->next = blockhead;
 369         blockhead = bp;
 370         bp->block = (char *) xmalloc(1024);
 371         if (read(fd, bp->block, 1024) != 1024) {
 372                 fprintf(stderr, "read error, sector %d\n", secnr);
 373                 bp->block = NULL;
 374         }
 375         return bp->block;
 376 }
 377
 378 /* call with errno and integer m and error message */
 379 /* merge to interval m-n */
 380 static void
 381 errmerge(int err, int m, char *msg1, char *msg2) {
 382         static int preverr, firstm, prevm;
 383
 384         if (err != preverr) {
 385                 if (preverr) {
 386                         if (firstm == prevm)
 387                                 fprintf(stderr, msg1, firstm);
 388                         else
 389                                 fprintf(stderr, msg2, firstm, prevm);
 390                         errno = preverr;
 391                         perror("BLKPG");
 392                 }
 393                 preverr = err;
 394                 firstm = prevm = m;
 395         } else
 396                 prevm = m;
 397 }