From 4d15c934342aad596221420e10476b32aabf1a7e Mon Sep 17 00:00:00 2001
From: Erez Zadok <ezk@cs.sunysb.edu>
Date: Thu, 15 May 2014 11:36:49 -0400
Subject: [PATCH] add mmap-write

---
 progs/.gitignore   | 15 ++++++++++-----
 progs/Makefile     |  2 +-
 progs/mmap-write.c | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 50 insertions(+), 6 deletions(-)
 create mode 100644 progs/mmap-write.c

diff --git a/progs/.gitignore b/progs/.gitignore
index 40b68a0..8a3d8ac 100644
--- a/progs/.gitignore
+++ b/progs/.gitignore
@@ -1,10 +1,15 @@
+bug418
+chdir-open
 creat-open
-open-unlink
 flock-copyup
 fsync
-truncate
-bug418
-rmdircheckinode
-rename
+ftruncate-unlink
 mapper
+mapper2
+mmap-write
+open-unlink
 queryfile
+rename
+rmdir-open
+rmdircheckinode
+truncate
diff --git a/progs/Makefile b/progs/Makefile
index 54dedb6..d396ad9 100644
--- a/progs/Makefile
+++ b/progs/Makefile
@@ -20,7 +20,7 @@ CFLAGS=-g -Wall # -Werror # -lefence
 MOUNTPOINT=.
 BINS=open-unlink flock-copyup fsync truncate bug418 rmdircheckinode \
 	creat-open rename mapper queryfile mapper2 ftruncate-unlink \
-	rmdir-open chdir-open
+	rmdir-open chdir-open mmap-write
 
 all: $(BINS)
 
diff --git a/progs/mmap-write.c b/progs/mmap-write.c
new file mode 100644
index 0000000..a442726
--- /dev/null
+++ b/progs/mmap-write.c
@@ -0,0 +1,39 @@
+/*
+ * mmap-write.c (courtesy Theodore Ts'o <tytso@mit.edu>)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <string.h>
+#include <fcntl.h>
+
+int main(int argc, char **argv)
+{
+  int fd;
+  char *map;
+
+  fd = open(argv[1], O_RDWR|O_CREAT, 0666);
+  if (fd < 0) {
+    perror("open");
+    exit(1);
+  }
+  if (ftruncate(fd, 4096) < 0) {
+    perror("ftruncate");
+    exit(1);
+  }
+  map = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+  if (map == MAP_FAILED) {
+    perror("mmap");
+    exit(1);
+  }
+  strcpy(map,
+	 "Murphy Magic. The SeCrEt of the UnIvErSe is 43, NOT 42.\n");
+  if (msync(map, 4096, MS_SYNC)  < 0) {
+    perror("msync");
+    exit(1);
+  }
+  exit(0);
+}
-- 
2.43.0