lib/ext2fs/getsize.c

   1 /*
   2  * getsize.c --- get the size of a partition.
   3  *
   4  * Copyright (C) 1995, 1995 Theodore Ts'o.
   5  * Copyright (C) 2003 VMware, Inc.
   6  *
   7  * Windows version of ext2fs_get_device_size by Chris Li, VMware.
   8  *
   9  * %Begin-Header%
  10  * This file may be redistributed under the terms of the GNU Library
  11  * General Public License, version 2.
  12  * %End-Header%
  13  */
  14
  15 #ifndef _LARGEFILE_SOURCE
  16 #define _LARGEFILE_SOURCE
  17 #endif
  18 #ifndef _LARGEFILE64_SOURCE
  19 #define _LARGEFILE64_SOURCE
  20 #endif
  21
  22 #include "config.h"
  23 #include <stdio.h>
  24 #if HAVE_UNISTD_H
  25 #include <unistd.h>
  26 #endif
  27 #if HAVE_ERRNO_H
  28 #include <errno.h>
  29 #endif
  30 #include <fcntl.h>
  31 #ifdef HAVE_SYS_IOCTL_H
  32 #include <sys/ioctl.h>
  33 #endif
  34 #ifdef HAVE_LINUX_FD_H
  35 #include <linux/fd.h>
  36 #endif
  37 #ifdef HAVE_SYS_DISKLABEL_H
  38 #include <sys/disklabel.h>
  39 #endif
  40 #ifdef HAVE_SYS_DISK_H
  41 #include <sys/disk.h>
  42 #endif
  43 #ifdef __linux__
  44 #include <sys/utsname.h>
  45 #endif
  46 #if HAVE_SYS_STAT_H
  47 #include <sys/stat.h>
  48 #endif
  49 #include <ctype.h>
  50
  51 #if defined(__linux__) && defined(_IO) && !defined(BLKGETSIZE)
  52 #define BLKGETSIZE _IO(0x12,96) /* return device size */
  53 #endif
  54
  55 #if defined(__linux__) && defined(_IOR) && !defined(BLKGETSIZE64)
  56 #define BLKGETSIZE64 _IOR(0x12,114,size_t)      /* return device size in bytes (u64 *arg) */
  57 #endif
  58
  59 #ifdef APPLE_DARWIN
  60 #define BLKGETSIZE DKIOCGETBLOCKCOUNT32
  61 #endif /* APPLE_DARWIN */
  62
  63 #include "ext2_fs.h"
  64 #include "ext2fs.h"
  65
  66 #if defined(__CYGWIN__) || defined (WIN32)
  67 #include "windows.h"
  68 #include "winioctl.h"
  69
  70 #if (_WIN32_WINNT >= 0x0500)
  71 #define HAVE_GET_FILE_SIZE_EX 1
  72 #endif
  73
  74 errcode_t ext2fs_get_device_size2(const char *file, int blocksize,
  75                                   blk64_t *retblocks)
  76 {
  77         HANDLE dev;
  78         PARTITION_INFORMATION pi;
  79         DISK_GEOMETRY gi;
  80         DWORD retbytes;
  81 #ifdef HAVE_GET_FILE_SIZE_EX
  82         LARGE_INTEGER filesize;
  83 #else
  84         DWORD filesize;
  85 #endif /* HAVE_GET_FILE_SIZE_EX */
  86
  87         dev = CreateFile(file, GENERIC_READ,
  88                          FILE_SHARE_READ | FILE_SHARE_WRITE ,
  89                          NULL,  OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,  NULL);
  90
  91         if (dev == INVALID_HANDLE_VALUE)
  92                 return EBADF;
  93         if (DeviceIoControl(dev, IOCTL_DISK_GET_PARTITION_INFO,
  94                             &pi, sizeof(PARTITION_INFORMATION),
  95                             &pi, sizeof(PARTITION_INFORMATION),
  96                             &retbytes, NULL)) {
  97
  98                 *retblocks = pi.PartitionLength.QuadPart / blocksize;
  99
 100         } else if (DeviceIoControl(dev, IOCTL_DISK_GET_DRIVE_GEOMETRY,
 101                                 &gi, sizeof(DISK_GEOMETRY),
 102                                 &gi, sizeof(DISK_GEOMETRY),
 103                                 &retbytes, NULL)) {
 104
 105                 *retblocks = gi.BytesPerSector *
 106                              gi.SectorsPerTrack *
 107                              gi.TracksPerCylinder *
 108                              gi.Cylinders.QuadPart / blocksize;
 109
 110 #ifdef HAVE_GET_FILE_SIZE_EX
 111         } else if (GetFileSizeEx(dev, &filesize)) {
 112                 *retblocks = filesize.QuadPart / blocksize;
 113         }
 114 #else
 115         } else {
 116                 filesize = GetFileSize(dev, NULL);
 117                 if (INVALID_FILE_SIZE != filesize) {
 118                         *retblocks = filesize / blocksize;
 119                 }
 120         }
 121 #endif /* HAVE_GET_FILE_SIZE_EX */
 122
 123         CloseHandle(dev);
 124         return 0;
 125 }
 126
 127 #else
 128
 129 static int valid_offset (int fd, ext2_loff_t offset)
 130 {
 131         char ch;
 132
 133         if (ext2fs_llseek (fd, offset, 0) < 0)
 134                 return 0;
 135         if (read (fd, &ch, 1) < 1)
 136                 return 0;
 137         return 1;
 138 }
 139
 140 /*
 141  * Returns the number of blocks in a partition
 142  */
 143 errcode_t ext2fs_get_device_size2(const char *file, int blocksize,
 144                                   blk64_t *retblocks)
 145 {
 146         int     fd, rc = 0;
 147         unsigned long long size64;
 148         ext2_loff_t high, low;
 149
 150         fd = ext2fs_open_file(file, O_RDONLY, 0);
 151         if (fd < 0)
 152                 return errno;
 153
 154 #ifdef DKIOCGETBLOCKCOUNT       /* For Apple Darwin */
 155         if (ioctl(fd, DKIOCGETBLOCKCOUNT, &size64) >= 0) {
 156                 *retblocks = size64 / (blocksize / 512);
 157                 goto out;
 158         }
 159 #endif
 160
 161 #ifdef BLKGETSIZE64
 162         {
 163                 int valid_blkgetsize64 = 1;
 164 #ifdef __linux__
 165                 struct utsname ut;
 166
 167                 if ((uname(&ut) == 0) &&
 168                     ((ut.release[0] == '2') && (ut.release[1] == '.') &&
 169                      (ut.release[2] < '6') && (ut.release[3] == '.')))
 170                         valid_blkgetsize64 = 0;
 171 #endif
 172                 if (valid_blkgetsize64 &&
 173                     ioctl(fd, BLKGETSIZE64, &size64) >= 0) {
 174                         *retblocks = size64 / blocksize;
 175                         goto out;
 176                 }
 177         }
 178 #endif /* BLKGETSIZE64 */
 179
 180 #ifdef BLKGETSIZE
 181         {
 182                 unsigned long   size;
 183
 184                 if (ioctl(fd, BLKGETSIZE, &size) >= 0) {
 185                         *retblocks = size / (blocksize / 512);
 186                         goto out;
 187                 }
 188         }
 189 #endif
 190
 191 #ifdef FDGETPRM
 192         {
 193                 struct floppy_struct this_floppy;
 194
 195                 if (ioctl(fd, FDGETPRM, &this_floppy) >= 0) {
 196                         *retblocks = this_floppy.size / (blocksize / 512);
 197                         goto out;
 198                 }
 199         }
 200 #endif
 201
 202 #ifdef HAVE_SYS_DISKLABEL_H
 203         {
 204                 int part;
 205                 struct disklabel lab;
 206                 struct partition *pp;
 207                 char ch;
 208
 209 #if defined(DIOCGMEDIASIZE)
 210                 {
 211                         off_t ms;
 212                         u_int bs;
 213                         if (ioctl(fd, DIOCGMEDIASIZE, &ms) >= 0) {
 214                                 *retblocks = ms / blocksize;
 215                                 goto out;
 216                         }
 217                 }
 218 #elif defined(DIOCGDINFO)
 219                 /* old disklabel interface */
 220                 part = strlen(file) - 1;
 221                 if (part >= 0) {
 222                         ch = file[part];
 223                         if (isdigit(ch))
 224                                 part = 0;
 225                         else if (ch >= 'a' && ch <= 'h')
 226                                 part = ch - 'a';
 227                         else
 228                                 part = -1;
 229                 }
 230                 if (part >= 0 && (ioctl(fd, DIOCGDINFO, (char *)&lab) >= 0)) {
 231                         pp = &lab.d_partitions[part];
 232                         if (pp->p_size) {
 233                                 *retblocks = pp->p_size / (blocksize / 512);
 234                                 goto out;
 235                         }
 236                 }
 237 #endif /* defined(DIOCG*) */
 238         }
 239 #endif /* HAVE_SYS_DISKLABEL_H */
 240
 241         {
 242                 ext2fs_struct_stat st;
 243
 244                 if (ext2fs_fstat(fd, &st) == 0)
 245                         if (S_ISREG(st.st_mode)) {
 246                                 *retblocks = st.st_size / blocksize;
 247                                 goto out;
 248                         }
 249         }
 250
 251         /*
 252          * OK, we couldn't figure it out by using a specialized ioctl,
 253          * which is generally the best way.  So do binary search to
 254          * find the size of the partition.
 255          */
 256         low = 0;
 257         for (high = 1024; valid_offset(fd, high); high *= 2)
 258                 low = high;
 259         while (low < high - 1) {
 260                 const ext2_loff_t mid = (low + high) / 2;
 261
 262                 if (valid_offset (fd, mid))
 263                         low = mid;
 264                 else
 265                         high = mid;
 266         }
 267         valid_offset(fd, 0);
 268         size64 = low + 1;
 269         *retblocks = size64 / blocksize;
 270 out:
 271         close(fd);
 272         return rc;
 273 }
 274
 275 #endif /* WIN32 */
 276
 277 errcode_t ext2fs_get_device_size(const char *file, int blocksize,
 278                                  blk_t *retblocks)
 279 {
 280         errcode_t retval;
 281         blk64_t blocks;
 282
 283         retval = ext2fs_get_device_size2(file, blocksize, &blocks);
 284         if (retval)
 285                 return retval;
 286         if (blocks >= (1ULL << 32))
 287                 return EFBIG;
 288         *retblocks = (blk_t) blocks;
 289         return 0;
 290 }
 291
 292 #ifdef DEBUG
 293 int main(int argc, char **argv)
 294 {
 295         blk_t   blocks;
 296         int     retval;
 297
 298         if (argc < 2) {
 299                 fprintf(stderr, "Usage: %s device\n", argv[0]);
 300                 exit(1);
 301         }
 302
 303         retval = ext2fs_get_device_size(argv[1], 1024, &blocks);
 304         if (retval) {
 305                 com_err(argv[0], retval,
 306                         "while calling ext2fs_get_device_size");
 307                 exit(1);
 308         }
 309         printf("Device %s has %u 1k blocks.\n", argv[1], blocks);
 310         exit(0);
 311 }
 312 #endif