The branch main has been updated by imp:
URL:
https://cgit.FreeBSD.org/src/commit/?id=cf04a7775a4e8ff6fd28c768be9daa3d83dd382e
commit cf04a7775a4e8ff6fd28c768be9daa3d83dd382e
Author: Ricardo Branco <rbra...@suse.de>
AuthorDate: 2024-04-23 21:47:56 +0000
Commit: Warner Losh <i...@freebsd.org>
CommitDate: 2024-04-23 21:48:01 +0000
swapon: Do not overwrite Linux swap header
Reviewed by: imp, jhb
Pull Request: https://github.com/freebsd/freebsd-src/pull/1084
---
sbin/swapon/Makefile | 2 ++
sbin/swapon/extern.h | 5 ++++
sbin/swapon/swaplinux.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++
sbin/swapon/swapon.c | 54 +++++++++++++++++++++++++++++++++++++++-
4 files changed, 126 insertions(+), 1 deletion(-)
diff --git a/sbin/swapon/Makefile b/sbin/swapon/Makefile
index 27808aed5857..930e938e5b05 100644
--- a/sbin/swapon/Makefile
+++ b/sbin/swapon/Makefile
@@ -6,6 +6,8 @@ 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
new file mode 100644
index 000000000000..cb33dbbee953
--- /dev/null
+++ b/sbin/swapon/extern.h
@@ -0,0 +1,5 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+int is_linux_swap(const char *);
diff --git a/sbin/swapon/swaplinux.c b/sbin/swapon/swaplinux.c
new file mode 100644
index 000000000000..d01a94345e68
--- /dev/null
+++ b/sbin/swapon/swaplinux.c
@@ -0,0 +1,66 @@
+/*-
+ * 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 26a7dc22654a..0f2ad1f5e213 100644
--- a/sbin/swapon/swapon.c
+++ b/sbin/swapon/swapon.c
@@ -54,10 +54,15 @@
#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);
@@ -250,8 +255,13 @@ swap_on_off(const char *name, int doingall, char *mntops)
return (swap_on_off_geli(name, mntops, doingall));
}
- /* Swap on special file. */
free(basebuf);
+
+ /* Linux swap */
+ if (is_linux_swap(name))
+ return (swap_on_off_linux(name, doingall));
+
+ /* Swap on special file. */
return (swap_on_off_sfile(name, doingall));
}
@@ -466,6 +476,48 @@ swap_on_off_geli(const char *name, char *mntops, int
doingall)
return (swap_on_off_sfile(name, 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)
{
