1 files changed, 128 insertions, 0 deletions
diff --git a/sbin/newfs/mfs.c b/sbin/newfs/mfs.c
new file mode 100644
index 000000000000..ce265f6fcf9b
--- /dev/null
+++ b/sbin/newfs/mfs.c
@@ -0,0 +1,128 @@
+#ifdef MFS
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/errno.h>
+#include <sys/signal.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/mount.h>
+
+
+
+static void
+sighandler()
+{
+	/*
+	 * kernel notifies us that the FS has been mounted successfully.
+	 */
+	exit(0);
+}
+
+
+void
+mfs_mount(addr, len, name, dir, flags)
+caddr_t		addr;
+unsigned long	len;
+char		*name, *dir;
+int		flags;
+{
+	struct mfs_args	margs;
+	char		nmbuf[16];
+	int		pfeife[2];
+	char		buf[1024];
+	int		red;
+
+
+
+	signal(SIGUSR1, sighandler);
+	if (pipe(pfeife) == -1)
+		fatal("cannot create pipe: %s", strerror(errno));
+	switch (fork()) {
+		case -1:
+			fatal("cannot fork: %s", strerror(errno));
+		case 0:
+			/*
+			 * child: disassociate from controlling terminal,
+			 * and mount the filesystem.
+			 */
+			dup2(pfeife[1], 2);
+			close(0);
+			close(1);
+			if (pfeife[0] != 2) close(pfeife[0]);
+			if (pfeife[1] != 2) close(pfeife[1]);
+			setsid();
+			(void)chdir("/");
+			if (name == 0) {
+				sprintf(nmbuf, "MFS:%d", getpid());
+				name = nmbuf;
+			}
+			margs.name  = name;
+			margs.base  = addr;
+			margs.size  = len;
+			margs.flags = MFSMNT_SIGPPID;
+			if (mount(MOUNT_MFS, dir, flags, &margs) == -1)
+				fatal("mounting MFS: %s", strerror(errno));
+		default:
+			/*
+			 * parent; if the mount system call fails, the
+			 * child will write error messages to the pipe.
+			 * We duplicate those messages to our stdout.
+			 * If the mount succeedet, we will receive a SIGUSR1
+			 * (and exit with status 0).
+			 */
+			close(pfeife[1]);
+			while ((red = read(pfeife[0], buf, sizeof(buf))) > 0)
+				write(2, buf, red);
+			exit(1);
+	}
+	/* NOTREACHED */
+}
+
+
+caddr_t
+mfs_malloc(size)
+unsigned long	size;
+{
+	caddr_t	addr;
+
+	addr = mmap(0, size, PROT_READ | PROT_WRITE,
+			MAP_ANON | MAP_SHARED, -1, 0);
+	if (addr == (caddr_t)-1)
+		fatal("cannot allocate memory: %s", strerror(errno));
+	return(addr);
+}
+
+void
+mfs_mountfile(file, dir, flags)
+char		*file, *dir;
+int		flags;
+{
+	caddr_t		addr;
+	int		fd;
+	struct stat	st;
+
+
+	fd = open(file, O_RDWR | O_EXLOCK);
+	if ((fd == -1) || (fstat(fd, &st) == -1))
+		fatal("%s: %s", file, strerror(errno));
+	addr = mmap(0, st.st_size, PROT_READ | PROT_WRITE,
+			MAP_FILE | MAP_SHARED, fd, 0);
+	if (addr == (caddr_t) -1)
+		fatal("cannot mmap file: %s", strerror(errno));
+	mfs_mount(addr, st.st_size, file, dir, flags);
+}
+
+#else
+caddr_t
+mfs_malloc()
+{
+	fatal("compiled without MFS support");
+	return(0);
+}
+void mfs_mount() {}
+void mfs_mountfile() {mfs_malloc();}
+#endif