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