| /* vi: set sw=4 ts=4: */ |
| /* |
| * getsize.c --- get the size of a partition. |
| * |
| * Copyright (C) 1995, 1995 Theodore Ts'o. |
| * |
| * %Begin-Header% |
| * This file may be redistributed under the terms of the |
| * GNU Lesser General Public License. |
| * %End-Header% |
| */ |
| |
| /* include this before sys/queues.h! */ |
| #include "blkidP.h" |
| |
| #include <stdio.h> |
| #include <unistd.h> |
| #ifdef HAVE_ERRNO_H |
| #include <errno.h> |
| #endif |
| #include <fcntl.h> |
| #ifdef HAVE_SYS_IOCTL_H |
| #include <sys/ioctl.h> |
| #endif |
| #ifdef HAVE_LINUX_FD_H |
| #include <linux/fd.h> |
| #endif |
| #ifdef HAVE_SYS_DISKLABEL_H |
| #include <sys/disklabel.h> |
| #include <sys/stat.h> |
| #endif |
| #ifdef HAVE_SYS_DISK_H |
| #ifdef HAVE_SYS_QUEUE_H |
| #include <sys/queue.h> /* for LIST_HEAD */ |
| #endif |
| #include <sys/disk.h> |
| #endif |
| #ifdef __linux__ |
| #include <sys/utsname.h> |
| #endif |
| |
| #if defined(__linux__) && defined(_IO) && !defined(BLKGETSIZE) |
| #define BLKGETSIZE _IO(0x12,96) /* return device size */ |
| #endif |
| |
| #if defined(__linux__) && defined(_IOR) && !defined(BLKGETSIZE64) |
| #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */ |
| #endif |
| |
| #ifdef APPLE_DARWIN |
| #define BLKGETSIZE DKIOCGETBLOCKCOUNT32 |
| #endif /* APPLE_DARWIN */ |
| |
| static int valid_offset(int fd, blkid_loff_t offset) |
| { |
| char ch; |
| |
| if (blkid_llseek(fd, offset, 0) < 0) |
| return 0; |
| if (read(fd, &ch, 1) < 1) |
| return 0; |
| return 1; |
| } |
| |
| /* |
| * Returns the number of blocks in a partition |
| */ |
| blkid_loff_t blkid_get_dev_size(int fd) |
| { |
| int valid_blkgetsize64 = 1; |
| #ifdef __linux__ |
| struct utsname ut; |
| #endif |
| unsigned long long size64; |
| unsigned long size; |
| blkid_loff_t high, low; |
| #ifdef FDGETPRM |
| struct floppy_struct this_floppy; |
| #endif |
| #ifdef HAVE_SYS_DISKLABEL_H |
| int part = -1; |
| struct disklabel lab; |
| struct partition *pp; |
| char ch; |
| struct stat st; |
| #endif /* HAVE_SYS_DISKLABEL_H */ |
| |
| #ifdef DKIOCGETBLOCKCOUNT /* For Apple Darwin */ |
| if (ioctl(fd, DKIOCGETBLOCKCOUNT, &size64) >= 0) { |
| if ((sizeof(blkid_loff_t) < sizeof(unsigned long long)) |
| && (size64 << 9 > 0xFFFFFFFF)) |
| return 0; /* EFBIG */ |
| return (blkid_loff_t) size64 << 9; |
| } |
| #endif |
| |
| #ifdef BLKGETSIZE64 |
| #ifdef __linux__ |
| uname(&ut); |
| if ((ut.release[0] == '2') && (ut.release[1] == '.') && |
| (ut.release[2] < '6') && (ut.release[3] == '.')) |
| valid_blkgetsize64 = 0; |
| #endif |
| if (valid_blkgetsize64 && |
| ioctl(fd, BLKGETSIZE64, &size64) >= 0) { |
| if ((sizeof(blkid_loff_t) < sizeof(unsigned long long)) |
| && ((size64) > 0xFFFFFFFF)) |
| return 0; /* EFBIG */ |
| return size64; |
| } |
| #endif |
| |
| #ifdef BLKGETSIZE |
| if (ioctl(fd, BLKGETSIZE, &size) >= 0) |
| return (blkid_loff_t)size << 9; |
| #endif |
| |
| #ifdef FDGETPRM |
| if (ioctl(fd, FDGETPRM, &this_floppy) >= 0) |
| return (blkid_loff_t)this_floppy.size << 9; |
| #endif |
| #ifdef HAVE_SYS_DISKLABEL_H |
| #if 0 |
| /* |
| * This should work in theory but I haven't tested it. Anyone |
| * on a BSD system want to test this for me? In the meantime, |
| * binary search mechanism should work just fine. |
| */ |
| if ((fstat(fd, &st) >= 0) && S_ISBLK(st.st_mode)) |
| part = st.st_rdev & 7; |
| if (part >= 0 && (ioctl(fd, DIOCGDINFO, (char *)&lab) >= 0)) { |
| pp = &lab.d_partitions[part]; |
| if (pp->p_size) |
| return pp->p_size << 9; |
| } |
| #endif |
| #endif /* HAVE_SYS_DISKLABEL_H */ |
| |
| /* |
| * OK, we couldn't figure it out by using a specialized ioctl, |
| * which is generally the best way. So do binary search to |
| * find the size of the partition. |
| */ |
| low = 0; |
| for (high = 1024; valid_offset(fd, high); high *= 2) |
| low = high; |
| while (low < high - 1) |
| { |
| const blkid_loff_t mid = (low + high) / 2; |
| |
| if (valid_offset(fd, mid)) |
| low = mid; |
| else |
| high = mid; |
| } |
| return low + 1; |
| } |
| |
| #ifdef TEST_PROGRAM |
| int main(int argc, char **argv) |
| { |
| blkid_loff_t bytes; |
| int fd; |
| |
| if (argc < 2) { |
| fprintf(stderr, "Usage: %s device\n" |
| "Determine the size of a device\n", argv[0]); |
| return 1; |
| } |
| |
| if ((fd = open(argv[1], O_RDONLY)) < 0) |
| perror(argv[0]); |
| |
| bytes = blkid_get_dev_size(fd); |
| printf("Device %s has %lld 1k blocks.\n", argv[1], bytes >> 10); |
| |
| return 0; |
| } |
| #endif |