create lfs policy. closes #73

src/fs.cpp

@@ -663,6 +663,49 @@ namespace fs
       return -1;
     }
 
+    int
+    lfs(const vector<string> &basepaths,
+        const string         &fusepath,
+        const size_t          minfreespace,
+        Paths                &paths)
+    {
+      fsblkcnt_t  lfs;
+      const char *lfsstr;
+
+      lfs    = -1;
+      lfsstr = NULL;
+      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) &&
+                 (spaceavail < lfs))
+                {
+                  lfs    = spaceavail;
+                  lfsstr = basepath;
+                }
+            }
+        }
+
+      if(lfsstr == NULL)
+        return mfs(basepaths,fusepath,minfreespace,paths);
+
+      paths.push_back(Path(lfsstr,
+                           fs::make_path(lfsstr,fusepath)));
+
+      return 0;
+    }
+
+
     int
     mfs(const vector<string> &basepaths,
         const string         &fusepath,

src/fs.hpp

@@ -148,6 +148,10 @@ namespace fs
                const string          &fusepath,
                const size_t           minfreespace,
                Paths                 &path);
+    int lfs(const vector<string>     &paths,
+            const string             &fusepath,
+            const size_t              minfreespace,
+            Paths                    &path);
     int mfs(const vector<string>     &paths,
             const string             &fusepath,
             const size_t              minfreespace,

src/policy.cpp

@@ -40,6 +40,7 @@ namespace mergerfs
     (POLICY(ff))
     (POLICY(ffwp))
     (POLICY(fwfs))
+    (POLICY(lfs))
     (POLICY(mfs))
     (POLICY(newest))
     (POLICY(rand));
@@ -52,6 +53,7 @@ namespace mergerfs
   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::lfs     = Policy::policies[Policy::Enum::lfs];
   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

@@ -46,6 +46,7 @@ namespace mergerfs
           ff,
           ffwp,
           fwfs,
+          lfs,
           mfs,
           newest,
           rand,
@@ -107,6 +108,7 @@ namespace mergerfs
     static const Policy              &ff;
     static const Policy              &ffwp;
     static const Policy              &fwfs;
+    static const Policy              &lfs;
     static const Policy              &mfs;
     static const Policy              &newest;
     static const Policy              &rand;