first w/ free space policy. closes #72

src/fs.cpp

@@ -594,6 +594,37 @@ namespace fs
       return -1;
     }
 
+    int
+    fwfs(const vector<string> &basepaths,
+         const string         &fusepath,
+         const size_t          minfreespace,
+         Paths                &paths)
+    {
+      for(size_t i = 0, size = basepaths.size(); i != size; i++)
+        {
+          int rv;
+          const char *basepath;
+          struct statvfs fsstats;
+
+          basepath = basepaths[i].c_str();
+          rv = ::statvfs(basepath,&fsstats);
+          if(rv == 0)
+            {
+              fsblkcnt_t spaceavail;
+
+              spaceavail = (fsstats.f_frsize * fsstats.f_bavail);
+              if(spaceavail > minfreespace)
+                {
+                  paths.push_back(Path(basepath,
+                                       fs::make_path(basepath,fusepath)));
+                  return 0;
+                }
+            }
+        }
+
+      return mfs(basepaths,fusepath,minfreespace,paths);
+    }
+
     int
     newest(const vector<string> &basepaths,
            const string         &fusepath,

src/fs.hpp

@@ -140,6 +140,10 @@ namespace fs
              const string            &fusepath,
              const size_t             minfreespace,
              Paths                   &path);
+    int fwfs(const vector<string>    &paths,
+             const string            &fusepath,
+             const size_t             minfreespace,
+             Paths                   &path);
     int newest(const vector<string>  &paths,
                const string          &fusepath,
                const size_t           minfreespace,

src/policy.cpp

@@ -39,6 +39,7 @@ namespace mergerfs
     (POLICY(epmfs))
     (POLICY(ff))
     (POLICY(ffwp))
+    (POLICY(fwfs))
     (POLICY(mfs))
     (POLICY(newest))
     (POLICY(rand));
@@ -50,6 +51,7 @@ namespace mergerfs
   const Policy &Policy::epmfs   = Policy::policies[Policy::Enum::epmfs];
   const Policy &Policy::ff      = Policy::policies[Policy::Enum::ff];
   const Policy &Policy::ffwp    = Policy::policies[Policy::Enum::ffwp];
+  const Policy &Policy::fwfs    = Policy::policies[Policy::Enum::fwfs];
   const Policy &Policy::mfs     = Policy::policies[Policy::Enum::mfs];
   const Policy &Policy::newest  = Policy::policies[Policy::Enum::newest];
   const Policy &Policy::rand    = Policy::policies[Policy::Enum::rand];

src/policy.hpp

@@ -45,6 +45,7 @@ namespace mergerfs
           epmfs,
           ff,
           ffwp,
+          fwfs,
           mfs,
           newest,
           rand,
@@ -105,6 +106,7 @@ namespace mergerfs
     static const Policy              &epmfs;
     static const Policy              &ff;
     static const Policy              &ffwp;
+    static const Policy              &fwfs;
     static const Policy              &mfs;
     static const Policy              &newest;
     static const Policy              &rand;