diff options
Diffstat (limited to 'e2fsprogs/blkid/blkid_getsize.c')
| -rw-r--r-- | e2fsprogs/blkid/blkid_getsize.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/e2fsprogs/blkid/blkid_getsize.c b/e2fsprogs/blkid/blkid_getsize.c new file mode 100644 index 000000000..9458c08bf --- /dev/null +++ b/e2fsprogs/blkid/blkid_getsize.c @@ -0,0 +1,180 @@ +/* + * 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> +#if HAVE_UNISTD_H +#include <unistd.h> +#endif +#if 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__ + if ((uname(&ut) == 0) && + ((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 %Ld 1k blocks.\n", argv[1], bytes >> 10); + + return 0; +} +#endif |