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Diffstat (limited to 'e2fsprogs/blkid/blkid_getsize.c')
-rw-r--r--e2fsprogs/blkid/blkid_getsize.c180
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 0000000..9458c08
--- /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