1 /* 2 * getsize.c --- get the size of a partition. 3 * 4 * Copyright (C) 1995, 1995 Theodore Ts'o. 5 * 6 * %Begin-Header% 7 * This file may be redistributed under the terms of the 8 * GNU Lesser General Public License. 9 * %End-Header% 10 */ 11 12 #define _LARGEFILE_SOURCE 13 #define _LARGEFILE64_SOURCE 14 15 /* include this before sys/queues.h! */ 16 #include "blkidP.h" 17 18 #include <stdio.h> 19 #if HAVE_UNISTD_H 20 #include <unistd.h> 21 #endif 22 #if HAVE_ERRNO_H 23 #include <errno.h> 24 #endif 25 #include <fcntl.h> 26 #ifdef HAVE_SYS_IOCTL_H 27 #include <sys/ioctl.h> 28 #endif 29 #ifdef HAVE_LINUX_FD_H 30 #include <linux/fd.h> 31 #endif 32 #ifdef HAVE_SYS_DISKLABEL_H 33 #include <sys/disklabel.h> 34 #endif 35 #ifdef HAVE_SYS_DISK_H 36 #ifdef HAVE_SYS_QUEUE_H 37 #include <sys/queue.h> /* for LIST_HEAD */ 38 #endif 39 #include <sys/disk.h> 40 #endif 41 #ifdef __linux__ 42 #include <sys/utsname.h> 43 #endif 44 #if HAVE_SYS_STAT_H 45 #include <sys/stat.h> 46 #endif 47 48 49 #if defined(__linux__) && defined(_IO) && !defined(BLKGETSIZE) 50 #define BLKGETSIZE _IO(0x12,96) /* return device size */ 51 #endif 52 53 #if defined(__linux__) && defined(_IOR) && !defined(BLKGETSIZE64) 54 #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */ 55 #endif 56 57 #ifdef APPLE_DARWIN 58 #define BLKGETSIZE DKIOCGETBLOCKCOUNT32 59 #endif /* APPLE_DARWIN */ 60 61 static int valid_offset(int fd, blkid_loff_t offset) 62 { 63 char ch; 64 65 if (blkid_llseek(fd, offset, 0) < 0) 66 return 0; 67 if (read(fd, &ch, 1) < 1) 68 return 0; 69 return 1; 70 } 71 72 /* 73 * Returns the number of bytes in a partition 74 */ 75 blkid_loff_t blkid_get_dev_size(int fd) 76 { 77 unsigned long long size64; 78 blkid_loff_t high, low; 79 80 #ifdef DKIOCGETBLOCKCOUNT /* For Apple Darwin */ 81 if (ioctl(fd, DKIOCGETBLOCKCOUNT, &size64) >= 0) { 82 if (sizeof(blkid_loff_t) < sizeof(unsigned long long) && 83 (size64 << 9) > 0xFFFFFFFF) 84 return 0; /* EFBIG */ 85 return (blkid_loff_t)size64 << 9; 86 } 87 #endif 88 89 #ifdef BLKGETSIZE64 90 { 91 int valid_blkgetsize64 = 1; 92 #ifdef __linux__ 93 struct utsname ut; 94 95 if ((uname(&ut) == 0) && 96 ((ut.release[0] == '2') && (ut.release[1] == '.') && 97 (ut.release[2] < '6') && (ut.release[3] == '.'))) 98 valid_blkgetsize64 = 0; 99 #endif 100 if (valid_blkgetsize64 && 101 ioctl(fd, BLKGETSIZE64, &size64) >= 0) { 102 if (sizeof(blkid_loff_t) < sizeof(unsigned long long) && 103 (size64 > 0xFFFFFFFF)) 104 return 0; /* EFBIG */ 105 return size64; 106 } 107 } 108 #endif /* BLKGETSIZE64 */ 109 110 #ifdef BLKGETSIZE 111 { 112 unsigned long size; 113 114 if (ioctl(fd, BLKGETSIZE, &size) >= 0) 115 return (blkid_loff_t)size << 9; 116 } 117 #endif 118 119 /* tested on FreeBSD 6.1-RELEASE i386 */ 120 #ifdef DIOCGMEDIASIZE 121 if (ioctl(fd, DIOCGMEDIASIZE, &size64) >= 0) 122 return (off_t)size64; 123 #endif /* DIOCGMEDIASIZE */ 124 125 #ifdef FDGETPRM 126 { 127 struct floppy_struct this_floppy; 128 129 if (ioctl(fd, FDGETPRM, &this_floppy) >= 0) 130 return (blkid_loff_t)this_floppy.size << 9; 131 } 132 #endif 133 #ifdef HAVE_SYS_DISKLABEL_H 134 { 135 int part = -1; 136 struct disklabel lab; 137 struct partition *pp; 138 char ch; 139 struct stat st; 140 141 /* 142 * This code works for FreeBSD 4.11 i386, except for the full 143 * device (such as /dev/ad0). It doesn't work properly for 144 * newer FreeBSD though. FreeBSD >= 5.0 should be covered by 145 * the DIOCGMEDIASIZE above however. 146 * 147 * Note that FreeBSD >= 4.0 has disk devices as unbuffered (raw, 148 * character) devices, so we need to check for S_ISCHR, too. 149 */ 150 if (fstat(fd, &st) >= 0 && 151 (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode))) 152 part = st.st_rdev & 7; 153 154 if (part >= 0 && (ioctl(fd, DIOCGDINFO, (char *)&lab) >= 0)) { 155 pp = &lab.d_partitions[part]; 156 if (pp->p_size) 157 return pp->p_size << 9; 158 } 159 } 160 #endif /* HAVE_SYS_DISKLABEL_H */ 161 { 162 #if defined(HAVE_FSTAT64) && !defined(__OSX_AVAILABLE_BUT_DEPRECATED) 163 struct stat64 st; 164 if (fstat64(fd, &st) == 0) 165 #else 166 struct stat st; 167 if (fstat(fd, &st) == 0) 168 #endif 169 if (S_ISREG(st.st_mode)) 170 return st.st_size; 171 } 172 173 /* 174 * OK, we couldn't figure it out by using a specialized ioctl, 175 * which is generally the best way. So do binary search to 176 * find the size of the partition. 177 */ 178 low = 0; 179 for (high = 1024; valid_offset(fd, high); high *= 2) 180 low = high; 181 while (low < high - 1) { 182 const blkid_loff_t mid = (low + high) / 2; 183 184 if (valid_offset(fd, mid)) 185 low = mid; 186 else 187 high = mid; 188 } 189 return low + 1; 190 } 191 192 #ifdef TEST_PROGRAM 193 int main(int argc, char **argv) 194 { 195 long long bytes; 196 int fd; 197 198 if (argc < 2) { 199 fprintf(stderr, "Usage: %s device\n" 200 "Determine the size of a device\n", argv[0]); 201 return 1; 202 } 203 204 if ((fd = open(argv[1], O_RDONLY)) < 0) 205 perror(argv[0]); 206 207 bytes = blkid_get_dev_size(fd); 208 printf("Device %s has %lld 1k blocks.\n", argv[1], 209 (unsigned long long)bytes >> 10); 210 211 return 0; 212 } 213 #endif 214
