From d1e063beb43e595680c65e3804d1f8ddff53373b Mon Sep 17 00:00:00 2001
From: Guido Guenther <agx@sigxcpu.org>
Date: Sat, 18 Nov 2006 23:48:07 +0100
Subject: Imported Debian version 0.3.8.8

---
 e2fslib/getsize.c | 157 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 157 insertions(+)
 create mode 100644 e2fslib/getsize.c

(limited to 'e2fslib/getsize.c')

diff --git a/e2fslib/getsize.c b/e2fslib/getsize.c
new file mode 100644
index 0000000..e8fadba
--- /dev/null
+++ b/e2fslib/getsize.c
@@ -0,0 +1,157 @@
+/*
+ * 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 Public
+ * License.
+ * %End-Header%
+ */
+
+#define _LARGEFILE_SOURCE
+#define _LARGEFILE64_SOURCE
+
+#include <stdio.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#if HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#include <fcntl.h>
+#ifdef HAVE_LINUX_FD_H
+#include <sys/ioctl.h>
+#include <linux/fd.h>
+#endif
+#ifdef HAVE_SYS_DISKLABEL_H
+#include <sys/ioctl.h>
+#include <sys/disklabel.h>
+#endif /* HAVE_SYS_DISKLABEL_H */
+
+#if defined(__linux__) && defined(_IO) && !defined(BLKGETSIZE)
+#define BLKGETSIZE _IO(0x12,96)	/* return device size */
+#endif
+
+#include "ext2_fs.h"
+#include "ext2fs.h"
+
+static int valid_offset (int fd, ext2_loff_t offset)
+{
+	char ch;
+
+	if (ext2fs_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
+ */
+errcode_t ext2fs_get_device_size(const char *file, int blocksize,
+				 blk_t *retblocks)
+{
+	int	fd;
+#ifdef BLKGETSIZE
+	unsigned long	size;
+#endif
+	ext2_loff_t high, low;
+#ifdef FDGETPRM
+	struct floppy_struct this_floppy;
+#endif
+#ifdef HAVE_SYS_DISKLABEL_H
+	int part;
+	struct disklabel lab;
+	struct partition *pp;
+	char ch;
+#endif /* HAVE_SYS_DISKLABEL_H */
+
+#ifdef HAVE_OPEN64
+	fd = open64(file, O_RDONLY);
+#else
+	fd = open(file, O_RDONLY);
+#endif
+	if (fd < 0)
+		return errno;
+
+#ifdef BLKGETSIZE
+	if (ioctl(fd, BLKGETSIZE, &size) >= 0) {
+		close(fd);
+		*retblocks = size / (blocksize / 512);
+		return 0;
+	}
+#endif
+#ifdef FDGETPRM
+	if (ioctl(fd, FDGETPRM, &this_floppy) >= 0) {
+		close(fd);
+		*retblocks = this_floppy.size / (blocksize / 512);
+		return 0;
+	}
+#endif
+#ifdef HAVE_SYS_DISKLABEL_H
+	part = strlen(file) - 1;
+	if (part >= 0) {
+		ch = file[part];
+		if (isdigit(ch))
+			part = 0;
+		else if (ch >= 'a' && ch <= 'h')
+			part = ch - 'a';
+		else
+			part = -1;
+	}
+	if (part >= 0 && (ioctl(fd, DIOCGDINFO, (char *)&lab) >= 0)) {
+		pp = &lab.d_partitions[part];
+		if (pp->p_size) {
+			close(fd);
+			*retblocks = pp->p_size / (blocksize / 512);
+			return 0;
+		}
+	}
+#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 ext2_loff_t mid = (low + high) / 2;
+
+		if (valid_offset (fd, mid))
+			low = mid;
+		else
+			high = mid;
+	}
+	valid_offset (fd, 0);
+	close(fd);
+	*retblocks = (low + 1) / blocksize;
+	return 0;
+}
+
+#ifdef DEBUG
+int main(int argc, char **argv)
+{
+	blk_t	blocks;
+	int	retval;
+	
+	if (argc < 2) {
+		fprintf(stderr, "Usage: %s device\n", argv[0]);
+		exit(1);
+	}
+
+	retval = ext2fs_get_device_size(argv[1], 1024, &blocks);
+	if (retval) {
+		com_err(argv[0], retval,
+			"while calling ext2fs_get_device_size");
+		exit(1);
+	}
+	printf("Device %s has %d 1k blocks.\n", argv[1], blocks);
+	exit(0);
+}
+#endif
-- 
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