1 files changed, 37 insertions, 0 deletions
diff --git a/mdk-stage1/dietlibc/lib/lockf.c b/mdk-stage1/dietlibc/lib/lockf.c
new file mode 100644
index 000000000..2b1d004ef
--- /dev/null
+++ b/mdk-stage1/dietlibc/lib/lockf.c
@@ -0,0 +1,37 @@
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+int lockf(int fd, int cmd, off_t len) {
+  struct flock fl;
+  fl.l_whence=SEEK_CUR;
+  fl.l_start=0;
+  fl.l_len=len;
+  fl.l_pid=0;
+  switch (cmd) {
+  case F_TEST:
+    if (fcntl(fd,F_GETLK,&fl)<0)
+      return -1;
+    if (fl.l_type == F_UNLCK || fl.l_pid == getpid ())
+      return 0;
+    errno=EACCES;
+    return -1;
+  case F_ULOCK:
+    fl.l_type=F_UNLCK;
+    cmd=F_SETLK;
+    break;
+  case F_LOCK:
+    fl.l_type = F_WRLCK;
+    cmd = F_SETLKW;
+    break;
+  case F_TLOCK:
+    fl.l_type = F_WRLCK;
+    cmd = F_SETLK;
+    break;
+  default:
+    errno=EINVAL;
+    return -1;
+  }
+  return fcntl(fd,cmd,&fl);
+}