Move from opening/closing disk for every i/o to opening the disk once

and saving the fd in the global 'disk' structure. Stop passing around
fd's and just use the global.

Makes pledge() feasible.

Prompted by and ok deraadt@

9 files changed, 96 insertions, 137 deletions

diff --git a/sbin/fdisk/cmd.c b/sbin/fdisk/cmd.c
index 9c2de8b3d3b..ba2feca8b37 100644
--- a/sbin/fdisk/cmd.c
+++ b/sbin/fdisk/cmd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cmd.c,v 1.84 2015/11/03 14:20:00 krw Exp $	*/
+/*	$OpenBSD: cmd.c,v 1.85 2015/11/13 02:27:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -397,7 +397,7 @@ int
 Xwrite(char *args, struct mbr *mbr)
 {
 	struct dos_mbr dos_mbr;
-	int fd, i, n;
+	int i, n;
 
 	for (i = 0, n = 0; i < NDOSPART; i++)
 		if (mbr->part[i].id == 0xA6)
@@ -408,37 +408,28 @@ Xwrite(char *args, struct mbr *mbr)
 			return (CMD_CONT);
 	}
 
-	fd = DISK_open(disk.name, O_RDWR);
 	MBR_make(mbr, &dos_mbr);
 
 	printf("Writing MBR at offset %lld.\n", (long long)mbr->offset);
-	if (MBR_write(fd, mbr->offset, &dos_mbr) == -1) {
-		int saved_errno = errno;
+	if (MBR_write(mbr->offset, &dos_mbr) == -1) {
 		warn("error writing MBR");
-		close(fd);
-		errno = saved_errno;
 		return (CMD_CONT);
 	}
 
 	if (letoh64(gh.gh_sig) == GPTSIGNATURE) {
 		printf("Writing GPT.\n");
-		if (GPT_write(fd) == -1) {
-			int saved_errno = errno;
+		if (GPT_write() == -1) {
 			warn("error writing GPT");
-			close(fd);
-			errno = saved_errno;
 			return (CMD_CONT);
 		}
 	} else if (reinited) {
 		/* Make sure GPT doesn't get in the way. */
-		MBR_zapgpt(fd, &dos_mbr, DL_GETDSIZE(&dl) - 1);
+		MBR_zapgpt(&dos_mbr, DL_GETDSIZE(&dl) - 1);
 	}
 
 	/* Refresh in memory copy to reflect what was just written. */
 	MBR_parse(&dos_mbr, mbr->offset, mbr->reloffset, mbr);
 
-	close(fd);
-
 	return (CMD_CLEAN);
 }
 
diff --git a/sbin/fdisk/disk.c b/sbin/fdisk/disk.c
index d6829094fb3..f191e60c596 100644
--- a/sbin/fdisk/disk.c
+++ b/sbin/fdisk/disk.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: disk.c,v 1.49 2015/11/11 15:39:18 krw Exp $	*/
+/*	$OpenBSD: disk.c,v 1.50 2015/11/13 02:27:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -36,49 +36,37 @@
 struct disk disk;
 struct disklabel dl;
 
-int
-DISK_open(char *disk, int mode)
+void
+DISK_open(void)
 {
 	struct stat st;
-	int fd;
+	u_int64_t sz, spc;
 
-	fd = opendev(disk, mode, OPENDEV_PART, NULL);
-	if (fd == -1)
-		err(1, "%s", disk);
-	if (fstat(fd, &st) == -1)
-		err(1, "%s", disk);
+	disk.fd = opendev(disk.name, O_RDWR, OPENDEV_PART, NULL);
+	if (disk.fd == -1)
+		err(1, "%s", disk.name);
+	if (fstat(disk.fd, &st) == -1)
+		err(1, "%s", disk.name);
 	if (!S_ISCHR(st.st_mode) && !S_ISREG(st.st_mode))
 		errx(1, "%s is not a character device or a regular file",
 		    disk);
 
-	return (fd);
-}
-
-void
-DISK_getlabelgeometry(void)
-{
-	u_int64_t sz, spc;
-	int fd;
-
 	/* Get label geometry. */
-	if ((fd = DISK_open(disk.name, O_RDONLY)) != -1) {
-		if (ioctl(fd, DIOCGPDINFO, &dl) == -1) {
-			warn("DIOCGPDINFO");
-		} else {
-			disk.cylinders = dl.d_ncylinders;
-			disk.heads = dl.d_ntracks;
-			disk.sectors = dl.d_nsectors;
-			/* MBR handles only first UINT32_MAX sectors. */
-			spc = (u_int64_t)disk.heads * disk.sectors;
-			sz = DL_GETDSIZE(&dl);
-			if (sz > UINT32_MAX) {
-				disk.cylinders = UINT32_MAX / spc;
-				disk.size = disk.cylinders * spc;
-			} else
-				disk.size = sz;
-			unit_types[SECTORS].conversion = dl.d_secsize;
-		}
-		close(fd);
+	if (ioctl(disk.fd, DIOCGPDINFO, &dl) == -1) {
+		warn("DIOCGPDINFO");
+	} else {
+		disk.cylinders = dl.d_ncylinders;
+		disk.heads = dl.d_ntracks;
+		disk.sectors = dl.d_nsectors;
+		/* MBR handles only first UINT32_MAX sectors. */
+		spc = (u_int64_t)disk.heads * disk.sectors;
+		sz = DL_GETDSIZE(&dl);
+		if (sz > UINT32_MAX) {
+			disk.cylinders = UINT32_MAX / spc;
+			disk.size = disk.cylinders * spc;
+		} else
+			disk.size = sz;
+		unit_types[SECTORS].conversion = dl.d_secsize;
 	}
 }
 
@@ -116,7 +104,7 @@ DISK_printgeometry(char *units)
  * The caller must free() the memory it gets.
  */
 char *
-DISK_readsector(int fd, off_t where)
+DISK_readsector(off_t where)
 {
 	int secsize;
 	char *secbuf;
@@ -126,7 +114,7 @@ DISK_readsector(int fd, off_t where)
 	secsize = dl.d_secsize;
 
 	where *= secsize;
-	off = lseek(fd, where, SEEK_SET);
+	off = lseek(disk.fd, where, SEEK_SET);
 	if (off != where)
 		return (NULL);
 
@@ -134,7 +122,7 @@ DISK_readsector(int fd, off_t where)
 	if (secbuf == NULL)
 		return (NULL);
 
-	len = read(fd, secbuf, secsize);
+	len = read(disk.fd, secbuf, secsize);
 	if (len == -1 || len != secsize) {
 		free(secbuf);
 		return (NULL);
@@ -149,7 +137,7 @@ DISK_readsector(int fd, off_t where)
  * errno if the write fails.
  */
 int
-DISK_writesector(int fd, char *secbuf, off_t where)
+DISK_writesector(char *secbuf, off_t where)
 {
 	int secsize;
 	ssize_t len;
@@ -159,9 +147,9 @@ DISK_writesector(int fd, char *secbuf, off_t where)
 	secsize = dl.d_secsize;
 
 	where *= secsize;
-	off = lseek(fd, where, SEEK_SET);
+	off = lseek(disk.fd, where, SEEK_SET);
 	if (off == where)
-		len = write(fd, secbuf, secsize);
+		len = write(disk.fd, secbuf, secsize);
 
 	if (len == -1 || len != secsize) {
 		/* short read or write */
diff --git a/sbin/fdisk/disk.h b/sbin/fdisk/disk.h
index c77dc16c2f6..e65b4cfac9f 100644
--- a/sbin/fdisk/disk.h
+++ b/sbin/fdisk/disk.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: disk.h,v 1.19 2015/03/30 17:11:49 krw Exp $	*/
+/*	$OpenBSD: disk.h,v 1.20 2015/11/13 02:27:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -20,18 +20,18 @@
 #define _DISK_H
 
 struct disk {
-	char *name;
+	char	 *name;
+	int	  fd;
 	u_int32_t cylinders;
 	u_int32_t heads;
 	u_int32_t sectors;
 	u_int32_t size;
 };
 
-int  DISK_open(char *, int);
-void DISK_getlabelgeometry(void);
+void  DISK_open(void);
 int  DISK_printgeometry(char *);
-char *DISK_readsector(int, off_t);
-int DISK_writesector(int, char *, off_t);
+char *DISK_readsector(off_t);
+int DISK_writesector(char *, off_t);
 
 extern struct disk disk;
 extern struct disklabel dl;
diff --git a/sbin/fdisk/fdisk.c b/sbin/fdisk/fdisk.c
index e19396bfbc7..5646c5926a5 100644
--- a/sbin/fdisk/fdisk.c
+++ b/sbin/fdisk/fdisk.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fdisk.c,v 1.80 2015/11/11 15:39:18 krw Exp $	*/
+/*	$OpenBSD: fdisk.c,v 1.81 2015/11/13 02:27:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -149,8 +149,7 @@ main(int argc, char *argv[])
 	else
 		disk.name = argv[0];
 
-	/* Start with the disklabel geometry and get the sector size. */
-	DISK_getlabelgeometry();
+	DISK_open();
 
 	if (b_arg > 0 && i_flag == 0) {
 		warnx("-b specified without -i");
@@ -199,9 +198,7 @@ main(int argc, char *argv[])
 
 	/* Create initial/default MBR. */
 	if (i_flag == 0) {
-		fd = DISK_open(disk.name, O_RDONLY);
-		error = MBR_read(fd, 0, &dos_mbr);
-		close(fd);
+		error = MBR_read(0, &dos_mbr);
 		if (error)
 			errx(1, "Can't read sector 0!");
 		MBR_parse(&dos_mbr, 0, 0, &initial_mbr);
@@ -252,5 +249,7 @@ main(int argc, char *argv[])
 	if (e_flag)
 		USER_edit(0, 0);
 
+	close(disk.fd);
+
 	return (0);
 }
diff --git a/sbin/fdisk/gpt.c b/sbin/fdisk/gpt.c
index 72a9a250b7d..a0e604ef5d8 100644
--- a/sbin/fdisk/gpt.c
+++ b/sbin/fdisk/gpt.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gpt.c,v 1.4 2015/11/12 21:31:36 krw Exp $	*/
+/*	$OpenBSD: gpt.c,v 1.5 2015/11/13 02:27:17 krw Exp $	*/
 /*
  * Copyright (c) 2015 Markus Muller <mmu@grummel.net>
  * Copyright (c) 2015 Kenneth R Westerback <krw@openbsd.org>
@@ -45,14 +45,14 @@ struct gpt_header gh;
 struct gpt_partition gp[NGPTPARTITIONS];
 
 int
-GPT_get_header(int fd, off_t where)
+GPT_get_header(off_t where)
 {
 	char *secbuf;
 	uint64_t partlastlba;
 	int partspersec;
 	uint32_t orig_gh_csum, new_gh_csum;
 
-	secbuf = DISK_readsector(fd, where);
+	secbuf = DISK_readsector(where);
 	if (secbuf == 0)
 		return (1);
 
@@ -146,7 +146,7 @@ GPT_get_header(int fd, off_t where)
 }
 
 int
-GPT_get_partition_table(int fd, off_t where)
+GPT_get_partition_table(off_t where)
 {
 	ssize_t len;
 	off_t off;
@@ -167,13 +167,13 @@ GPT_get_partition_table(int fd, off_t where)
 	memset(&gp, 0, sizeof(gp));
 
 	where *= dl.d_secsize;
-	off = lseek(fd, where, SEEK_SET);
+	off = lseek(disk.fd, where, SEEK_SET);
 	if (off == -1) {
 		DPRINTF("seek to gpt partition table @ sector %llu failed\n",
 		    (unsigned long long)where / dl.d_secsize);
 		return (1);
 	}
-	len = read(fd, &gp, secs * dl.d_secsize);
+	len = read(disk.fd, &gp, secs * dl.d_secsize);
 	if (len == -1 || len != secs * dl.d_secsize) {
 		DPRINTF("gpt partition table read failed.\n");
 		return (1);
@@ -193,31 +193,23 @@ GPT_get_partition_table(int fd, off_t where)
 int
 GPT_get_gpt(void)
 {
-	int fd, privalid, altvalid;
-
-	fd = DISK_open(disk.name, O_RDONLY);
+	int privalid, altvalid;
 
 	/*
 	 * primary header && primary partition table ||
 	 * alt header && alt partition table
 	 */
-	privalid = GPT_get_header(fd, GPTSECTOR);
+	privalid = GPT_get_header(GPTSECTOR);
+	if (privalid == 0)
+		privalid = GPT_get_partition_table(gh.gh_part_lba);
 	if (privalid == 0)
-		privalid = GPT_get_partition_table(fd, gh.gh_part_lba);
-	if (privalid == 0) {
-		close(fd);
 		return (0);
-	}
 
-	altvalid = GPT_get_header(fd, DL_GETDSIZE(&dl) - 1);
+	altvalid = GPT_get_header(DL_GETDSIZE(&dl) - 1);
+	if (altvalid == 0)
+		altvalid = GPT_get_partition_table(gh.gh_part_lba);
 	if (altvalid == 0)
-		altvalid = GPT_get_partition_table(fd, gh.gh_part_lba);
-	if (altvalid == 0) {
-		close(fd);
 		return (0);
-	}
-
-	close(fd);
 
 	return (1);
 }
@@ -383,7 +375,7 @@ GPT_init(void)
 }
 
 int
-GPT_write(int fd)
+GPT_write(void)
 {
 	char *secbuf;
 	const int secsize = unit_types[SECTORS].conversion;
@@ -406,12 +398,12 @@ GPT_write(int fd)
 	gh.gh_csum = 0;
 	gh.gh_csum = crc32((unsigned char *)&gh, letoh32(gh.gh_size));
 
-	secbuf = DISK_readsector(fd, 1);
+	secbuf = DISK_readsector(1);
 	if (secbuf == NULL)
 		return (-1);
 
 	memcpy(secbuf, &gh, sizeof(gh));
-	DISK_writesector(fd, secbuf, 1);
+	DISK_writesector(secbuf, 1);
 	free(secbuf);
 
 	gh.gh_lba_self = htole64(altgh);
@@ -420,12 +412,12 @@ GPT_write(int fd)
 	gh.gh_csum = 0;
 	gh.gh_csum = crc32((unsigned char *)&gh, letoh32(gh.gh_size));
 
-	secbuf = DISK_readsector(fd, altgh);
+	secbuf = DISK_readsector(altgh);
 	if (secbuf == NULL)
 		return (-1);
 
 	memcpy(secbuf, &gh, sizeof(gh));
-	DISK_writesector(fd, secbuf, altgh);
+	DISK_writesector(secbuf, altgh);
 	free(secbuf);
 
 	/*
@@ -435,9 +427,9 @@ GPT_write(int fd)
 	 * XXX ALWAYS NGPTPARTITIONS!
 	 * XXX ASSUME gp is multiple of sector size!
 	 */
-	off = lseek(fd, secsize * 2, SEEK_SET);
+	off = lseek(disk.fd, secsize * 2, SEEK_SET);
 	if (off == secsize * 2)
-		len = write(fd, &gp, sizeof(gp));
+		len = write(disk.fd, &gp, sizeof(gp));
 	else
 		len = -1;
 	if (len == -1 || len != sizeof(gp)) {
@@ -445,9 +437,9 @@ GPT_write(int fd)
 		return (-1);
 	}
 
-	off = lseek(fd, secsize * altgp, SEEK_SET);
+	off = lseek(disk.fd, secsize * altgp, SEEK_SET);
 	if (off == secsize * altgp)
-		len = write(fd, &gp, sizeof(gp));
+		len = write(disk.fd, &gp, sizeof(gp));
 	else
 		len = -1;
 
@@ -457,7 +449,7 @@ GPT_write(int fd)
 	}
 
 	/* Refresh in-kernel disklabel from the updated disk information. */
-	ioctl(fd, DIOCRLDINFO, 0);
+	ioctl(disk.fd, DIOCRLDINFO, 0);
 
 	return (0);
 }
diff --git a/sbin/fdisk/gpt.h b/sbin/fdisk/gpt.h
index 1caca02305b..a428709dedc 100644
--- a/sbin/fdisk/gpt.h
+++ b/sbin/fdisk/gpt.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gpt.h,v 1.2 2015/10/26 15:08:26 krw Exp $	*/
+/*	$OpenBSD: gpt.h,v 1.3 2015/11/13 02:27:17 krw Exp $	*/
 /*
  * Copyright (c) 2015 Markus Muller <mmu@grummel.net>
  * Copyright (c) 2015 Kenneth R Westerback <krw@openbsd.org>
@@ -16,11 +16,11 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-int GPT_get_hdr(int, off_t);
-int GPT_get_partition_table(int, off_t);
+int GPT_get_hdr(off_t);
+int GPT_get_partition_table(off_t);
 int GPT_get_gpt(void);
 int GPT_init(void);
-int GPT_write(int);
+int GPT_write(void);
 
 void GPT_print(char *);
 void GPT_print_part(int, char *);
diff --git a/sbin/fdisk/mbr.c b/sbin/fdisk/mbr.c
index 0d291481665..8a713ae942e 100644
--- a/sbin/fdisk/mbr.c
+++ b/sbin/fdisk/mbr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mbr.c,v 1.59 2015/11/12 23:49:37 krw Exp $	*/
+/*	$OpenBSD: mbr.c,v 1.60 2015/11/13 02:27:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -214,11 +214,11 @@ MBR_print(struct mbr *mbr, char *units)
 }
 
 int
-MBR_read(int fd, off_t where, struct dos_mbr *dos_mbr)
+MBR_read(off_t where, struct dos_mbr *dos_mbr)
 {
 	char *secbuf;
 
-	secbuf = DISK_readsector(fd, where);
+	secbuf = DISK_readsector(where);
 	if (secbuf == NULL)
 		return (-1);
 
@@ -229,11 +229,11 @@ MBR_read(int fd, off_t where, struct dos_mbr *dos_mbr)
 }
 
 int
-MBR_write(int fd, off_t where, struct dos_mbr *dos_mbr)
+MBR_write(off_t where, struct dos_mbr *dos_mbr)
 {
 	char *secbuf;
 
-	secbuf = DISK_readsector(fd, where);
+	secbuf = DISK_readsector(where);
 	if (secbuf == NULL)
 		return (-1);
 
@@ -242,10 +242,10 @@ MBR_write(int fd, off_t where, struct dos_mbr *dos_mbr)
 	 * write the sector back to "disk".
 	 */
 	memcpy(secbuf, dos_mbr, sizeof(*dos_mbr));
-	DISK_writesector(fd, secbuf, where);
+	DISK_writesector(secbuf, where);
 
 	/* Refresh in-kernel disklabel from the updated disk information. */
-	ioctl(fd, DIOCRLDINFO, 0);
+	ioctl(disk.fd, DIOCRLDINFO, 0);
 
 	free(secbuf);
 
@@ -261,11 +261,9 @@ MBR_pcopy(struct mbr *mbr)
 {
 	struct dos_partition dos_parts[NDOSPART];
 	struct dos_mbr dos_mbr;
-	int i, fd, error;
+	int i, error;
 
-	fd = DISK_open(disk.name, O_RDONLY);
-	error = MBR_read(fd, 0, &dos_mbr);
-	close(fd);
+	error = MBR_read(0, &dos_mbr);
 
 	if (error == -1)
 		return;
@@ -283,7 +281,7 @@ MBR_pcopy(struct mbr *mbr)
  * confused.
  */
 void
-MBR_zapgpt(int fd, struct dos_mbr *dos_mbr, uint64_t lastsec)
+MBR_zapgpt(struct dos_mbr *dos_mbr, uint64_t lastsec)
 {
 	struct dos_partition dos_parts[NDOSPART];
 	char *secbuf;
@@ -297,25 +295,25 @@ MBR_zapgpt(int fd, struct dos_mbr *dos_mbr, uint64_t lastsec)
 		    (dos_parts[i].dp_typ == DOSPTYP_EFISYS))
 			return;
 
-	secbuf = DISK_readsector(fd, GPTSECTOR);
+	secbuf = DISK_readsector(GPTSECTOR);
 	if (secbuf == NULL)
 		return;
 
 	memcpy(&sig, secbuf, sizeof(sig));
 	if (letoh64(sig) == GPTSIGNATURE) {
 		memset(secbuf, 0, sizeof(sig));
-		DISK_writesector(fd, secbuf, GPTSECTOR);
+		DISK_writesector(secbuf, GPTSECTOR);
 	}
 	free(secbuf);
 
-	secbuf = DISK_readsector(fd, lastsec);
+	secbuf = DISK_readsector(lastsec);
 	if (secbuf == NULL)
 		return;
 
 	memcpy(&sig, secbuf, sizeof(sig));
 	if (letoh64(sig) == GPTSIGNATURE) {
 		memset(secbuf, 0, sizeof(sig));
-		DISK_writesector(fd, secbuf, lastsec);
+		DISK_writesector(secbuf, lastsec);
 	}
 	free(secbuf);
 }
diff --git a/sbin/fdisk/mbr.h b/sbin/fdisk/mbr.h
index 0673f87fb45..7bb8bfb6f02 100644
--- a/sbin/fdisk/mbr.h
+++ b/sbin/fdisk/mbr.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mbr.h,v 1.26 2015/10/26 15:08:26 krw Exp $	*/
+/*	$OpenBSD: mbr.h,v 1.27 2015/11/13 02:27:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -34,10 +34,10 @@ void MBR_parse(struct dos_mbr *, off_t, off_t, struct mbr *);
 void MBR_make(struct mbr *, struct dos_mbr *);
 void MBR_init(struct mbr *);
 void MBR_init_GPT(struct mbr *);
-int MBR_read(int, off_t, struct dos_mbr *);
-int MBR_write(int, off_t, struct dos_mbr *);
+int MBR_read(off_t, struct dos_mbr *);
+int MBR_write(off_t, struct dos_mbr *);
 void MBR_pcopy(struct mbr *);
-void MBR_zapgpt(int, struct dos_mbr *, uint64_t);
+void MBR_zapgpt(struct dos_mbr *, uint64_t);
 void MBR_init_GPT(struct mbr *);
 int MBR_protective_mbr(struct mbr *);
 
diff --git a/sbin/fdisk/user.c b/sbin/fdisk/user.c
index 40d40a73253..b02b712d86a 100644
--- a/sbin/fdisk/user.c
+++ b/sbin/fdisk/user.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: user.c,v 1.45 2015/10/26 15:08:26 krw Exp $	*/
+/*	$OpenBSD: user.c,v 1.46 2015/11/13 02:27:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -24,7 +24,6 @@
 #include <string.h>
 #include <unistd.h>
 
-#include "disk.h"
 #include "part.h"
 #include "mbr.h"
 #include "misc.h"
@@ -62,15 +61,13 @@ USER_edit(off_t offset, off_t reloff)
 	struct dos_mbr dos_mbr;
 	struct mbr mbr;
 	char *cmd, *args;
-	int i, st, fd, error;
+	int i, st, error;
 
 	/* One level deeper */
 	editlevel += 1;
 
 	/* Read MBR & partition */
-	fd = DISK_open(disk.name, O_RDONLY);
-	error = MBR_read(fd, offset, &dos_mbr);
-	close(fd);
+	error = MBR_read(offset, &dos_mbr);
 	if (error == -1)
 		goto done;
 
@@ -122,7 +119,6 @@ again:
 		if (st == CMD_SAVE) {
 			if (Xwrite(NULL, &mbr) == CMD_CONT)
 				goto again;
-			close(fd);
 		} else
 			printf("Aborting changes to current MBR.\n");
 	}
@@ -136,15 +132,14 @@ void
 USER_print_disk(void)
 {
 	off_t offset, firstoff;
-	int fd, i, error;
+	int i, error;
 	struct dos_mbr dos_mbr;
 	struct mbr mbr;
 
-	fd = DISK_open(disk.name, O_RDONLY);
 	offset = firstoff = 0;
 
 	do {
-		error = MBR_read(fd, offset, &dos_mbr);
+		error = MBR_read(offset, &dos_mbr);
 		if (error == -1)
 			break;
 		MBR_parse(&dos_mbr, offset, firstoff, &mbr);
@@ -166,8 +161,4 @@ USER_print_disk(void)
 					firstoff = offset;
 			}
 	} while (offset);
-
-	error = close(fd);
-	if (error == -1)
-		err(1, "Unable to close disk");
 }