Revert "swapon: Do not overwrite Linux swap header"

This reverts commit cf04a7775a4e8ff6fd28c768be9daa3d83dd382e.This is
broken on armv7, and closer scrutiny of the reviews shows I was in error
when I thought it was ready.

4 files changed, 1 insertions, 126 deletions

diff --git a/sbin/swapon/Makefile b/sbin/swapon/Makefile
index 930e938e5b05..27808aed5857 100644
--- a/sbin/swapon/Makefile
+++ b/sbin/swapon/Makefile
@@ -6,8 +6,6 @@ LINKS=	${BINDIR}/swapon ${BINDIR}/swapoff
 LINKS+=	${BINDIR}/swapon ${BINDIR}/swapctl
 MLINKS=	swapon.8 swapoff.8
 MLINKS+=swapon.8 swapctl.8
-SRCS=	swapon.c swaplinux.c
-HDRS+=	extern.h
 
 LIBADD=	util
 
diff --git a/sbin/swapon/extern.h b/sbin/swapon/extern.h
deleted file mode 100644
index cb33dbbee953..000000000000
--- a/sbin/swapon/extern.h
+++ /dev/null
@@ -1,5 +0,0 @@
-/*-
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-int is_linux_swap(const char *);
diff --git a/sbin/swapon/swaplinux.c b/sbin/swapon/swaplinux.c
deleted file mode 100644
index d01a94345e68..000000000000
--- a/sbin/swapon/swaplinux.c
+++ /dev/null
@@ -1,66 +0,0 @@
-/*-
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#include <fcntl.h>
-#include <err.h>
-#include <stdint.h>
-#include <string.h>
-#include <unistd.h>
-
-#include "extern.h"
-
-/*
- * Definitions and structure taken from
- * https://github.com/util-linux/util-linux/blob/master/include/swapheader.h
- */
-
-#define SWAP_VERSION 1
-#define SWAP_UUID_LENGTH 16
-#define SWAP_LABEL_LENGTH 16
-#define SWAP_SIGNATURE "SWAPSPACE2"
-#define SWAP_SIGNATURE_SZ (sizeof(SWAP_SIGNATURE) - 1)
-
-struct swap_header_v1_2 {
-	char	      bootbits[1024];    /* Space for disklabel etc. */
-	uint32_t      version;
-	uint32_t      last_page;
-	uint32_t      nr_badpages;
-	unsigned char uuid[SWAP_UUID_LENGTH];
-	char	      volume_name[SWAP_LABEL_LENGTH];
-	uint32_t      padding[117];
-	uint32_t      badpages[1];
-};
-
-typedef union {
-	struct swap_header_v1_2 header;
-	struct {
-		uint8_t	reserved[4096 - SWAP_SIGNATURE_SZ];
-		char	signature[SWAP_SIGNATURE_SZ];
-	} tail;
-} swhdr_t;
-
-#define sw_version	header.version
-#define sw_volume_name	header.volume_name
-#define sw_signature	tail.signature
-
-int
-is_linux_swap(const char *name)
-{
-	uint8_t buf[4096];
-	swhdr_t *hdr = (swhdr_t *) buf;
-	int fd;
-
-	fd = open(name, O_RDONLY);
-	if (fd == -1)
-		return (-1);
-
-	if (read(fd, buf, 4096) != 4096) {
-		close(fd);
-		return (-1);
-	}
-	close(fd);
-
-	return (hdr->sw_version == SWAP_VERSION &&
-	    !memcmp(hdr->sw_signature, SWAP_SIGNATURE, SWAP_SIGNATURE_SZ));
-}
diff --git a/sbin/swapon/swapon.c b/sbin/swapon/swapon.c
index 0f2ad1f5e213..26a7dc22654a 100644
--- a/sbin/swapon/swapon.c
+++ b/sbin/swapon/swapon.c
@@ -54,15 +54,10 @@
 #include <string.h>
 #include <unistd.h>
 
-#include "extern.h"
-
-#define _PATH_GNOP	"/sbin/gnop"
-
 static void usage(void) __dead2;
 static const char *swap_on_off(const char *, int, char *);
 static const char *swap_on_off_gbde(const char *, int);
 static const char *swap_on_off_geli(const char *, char *, int);
-static const char *swap_on_off_linux(const char *, int);
 static const char *swap_on_off_md(const char *, char *, int);
 static const char *swap_on_off_sfile(const char *, int);
 static void swaplist(int, int, int);
@@ -255,13 +250,8 @@ swap_on_off(const char *name, int doingall, char *mntops)
 		return (swap_on_off_geli(name, mntops, doingall));
 	}
 
-	free(basebuf);
-
-	/* Linux swap */
-	if (is_linux_swap(name))
-		return (swap_on_off_linux(name, doingall));
-
 	/* Swap on special file. */
+	free(basebuf);
 	return (swap_on_off_sfile(name, doingall));
 }
 
@@ -477,48 +467,6 @@ swap_on_off_geli(const char *name, char *mntops, int doingall)
 }
 
 static const char *
-swap_on_off_linux(const char *name, int doingall)
-{
-	const char *ret;
-	char *nopname;
-	size_t nopnamelen;
-	int error;
-
-	if (which_prog == SWAPON) {
-		/* Skip the header for Linux swap partitions */
-		error = run_cmd(NULL, "%s create -o 4096 %s", _PATH_GNOP,
-		    name);
-		if (error) {
-			warnx("gnop (create) error: %s", name);
-			return (NULL);
-		}
-	}
-
-	/* Append ".nop" to name */
-	nopnamelen = strlen(name) + sizeof(".nop");
-	nopname = (char *) malloc(nopnamelen);
-	if (nopname == NULL)
-		err(1, "malloc()");
-	(void)strlcpy(nopname, name, nopnamelen);
-	(void)strlcat(nopname, ".nop", nopnamelen);
-
-	ret = swap_on_off_sfile(nopname, doingall);
-
-	if (which_prog == SWAPOFF) {
-		error = run_cmd(NULL, "%s destroy %s", _PATH_GNOP, nopname);
-		if (error) {
-			warnx("gnop (destroy) error: %s", name);
-			free(nopname);
-			return (NULL);
-		}
-	}
-
-	free(nopname);
-
-	return (ret);
-}
-
-static const char *
 swap_on_off_md(const char *name, char *mntops, int doingall)
 {
 	FILE *sfd;