From 8f594e17d7d48a6e9f1ab2d9b3ba233c40702ae1 Mon Sep 17 00:00:00 2001
From: Antonio SJ Musumeci <trapexit@spawn.link>
Date: Wed, 19 Oct 2016 11:58:44 -0400
Subject: [PATCH] add flock

---
 src/flock.cpp         | 49 +++++++++++++++++++++++++++++++++++++++++++
 src/flock.hpp         | 26 +++++++++++++++++++++++
 src/fs_base_flock.hpp | 31 +++++++++++++++++++++++++++
 src/mergerfs.cpp      |  3 ++-
 4 files changed, 108 insertions(+), 1 deletion(-)
 create mode 100644 src/flock.cpp
 create mode 100644 src/flock.hpp
 create mode 100644 src/fs_base_flock.hpp

diff --git a/src/flock.cpp b/src/flock.cpp
new file mode 100644
index 00000000..ba034b86
--- /dev/null
+++ b/src/flock.cpp
@@ -0,0 +1,49 @@
+/*
+  Copyright (c) 2016, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include <fuse.h>
+
+#include "errno.hpp"
+#include "fileinfo.hpp"
+#include "fs_base_flock.hpp"
+
+static
+int
+_flock(const int fd,
+       const int operation)
+{
+  int rv;
+
+  rv = fs::flock(fd,operation);
+
+  return ((rv == -1) ? -errno : 0);
+}
+
+namespace mergerfs
+{
+  namespace fuse
+  {
+    int
+    flock(const char     *fusepath,
+          fuse_file_info *ffi,
+          int             op)
+    {
+      FileInfo* fi = reinterpret_cast<FileInfo*>(ffi->fh);
+
+      return _flock(fi->fd,op);
+    }
+  }
+}
diff --git a/src/flock.hpp b/src/flock.hpp
new file mode 100644
index 00000000..8105e489
--- /dev/null
+++ b/src/flock.hpp
@@ -0,0 +1,26 @@
+/*
+  Copyright (c) 2016, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+namespace mergerfs
+{
+  namespace fuse
+  {
+    int
+    flock(const char     *fusepath,
+          fuse_file_info *ffi,
+          int             op);
+  }
+}
diff --git a/src/fs_base_flock.hpp b/src/fs_base_flock.hpp
new file mode 100644
index 00000000..31be991d
--- /dev/null
+++ b/src/fs_base_flock.hpp
@@ -0,0 +1,31 @@
+/*
+  ISC License
+
+  Copyright (c) 2016, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include <sys/file.h>
+
+namespace fs
+{
+  static
+  inline
+  int
+  flock(const int fd,
+        const int operation)
+  {
+    return ::flock(fd,operation);
+  }
+}
diff --git a/src/mergerfs.cpp b/src/mergerfs.cpp
index 4fb5d0c5..fabbac92 100644
--- a/src/mergerfs.cpp
+++ b/src/mergerfs.cpp
@@ -34,6 +34,7 @@
 #include "destroy.hpp"
 #include "fallocate.hpp"
 #include "fgetattr.hpp"
+#include "flock.hpp"
 #include "flush.hpp"
 #include "fsync.hpp"
 #include "ftruncate.hpp"
@@ -95,7 +96,7 @@ namespace local
 #endif
     ops.fgetattr    = mergerfs::fuse::fgetattr;
 #if FLOCK
-    ops.flock       = NULL;
+    ops.flock       = mergerfs::fuse::flock;
 #endif
     ops.flush       = mergerfs::fuse::flush;
     ops.fsync       = mergerfs::fuse::fsync;