Add support for FUSE passthrough

src/fuse_release.cpp

@@ -14,38 +14,87 @@
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
+#include "state.hpp"
+
 #include "config.hpp"
-#include "errno.hpp"
 #include "fileinfo.hpp"
 #include "fs_close.hpp"
 #include "fs_fadvise.hpp"
+#include "fuse_passthrough.hpp"
 
 #include "fuse.h"
 
-#include <string>
-
-
-namespace l
+static
+constexpr
+auto
+_erase_if_lambda(const fuse_context *fc_,
+                 FileInfo           *fi_,
+                 bool               *existed_in_map_)
 {
-  static
-  int
-  release(FileInfo   *fi_,
-          const bool  dropcacheonclose_)
-  {
-    // according to Feh of nocache calling it once doesn't always work
-    // https://github.com/Feh/nocache
-    if(dropcacheonclose_)
-      {
-        fs::fadvise_dontneed(fi_->fd);
-        fs::fadvise_dontneed(fi_->fd);
-      }
+  return
+    [=](auto &val_)
+    {
+      *existed_in_map_ = true;
 
-    fs::close(fi_->fd);
+      if(fi_ != val_.second.fi)
+        {
+          fs::close(fi_->fd);
+          delete fi_;
+        }
 
-    delete fi_;
+      val_.second.ref_count--;
+      if(val_.second.ref_count > 0)
+        return false;
 
+      if(val_.second.backing_id > 0)
+        FUSE::passthrough_close(fc_,val_.second.backing_id);
+      fs::close(val_.second.fi->fd);
+      delete val_.second.fi;
+
+      return true;
+    };
+}
+
+static
+int
+_release(const fuse_context *fc_,
+         FileInfo           *fi_,
+         const bool          dropcacheonclose_)
+{
+  bool existed_in_map;
+
+  // according to Feh of nocache calling it once doesn't always work
+  // https://github.com/Feh/nocache
+  if(dropcacheonclose_)
+    {
+      fs::fadvise_dontneed(fi_->fd);
+      fs::fadvise_dontneed(fi_->fd);
+    }
+
+  // Because of course the API doesn't tell you if the key
+  // existed. Just how many it erased and in this case I only want to
+  // erase if there are no more open files.
+  existed_in_map = false;
+  state.open_files.erase_if(fc_->nodeid,
+                            ::_erase_if_lambda(fc_,fi_,&existed_in_map));
+  if(existed_in_map)
     return 0;
-  }
+
+  fs::close(fi_->fd);
+  delete fi_;
+
+  return 0;
+}
+
+static
+int
+_release(const fuse_context     *fc_,
+         const fuse_file_info_t *ffi_)
+{
+  Config::Read cfg;
+  FileInfo *fi = reinterpret_cast<FileInfo*>(ffi_->fh);
+
+  return ::_release(fc_,fi,cfg->dropcacheonclose);
 }
 
 namespace FUSE
@@ -53,9 +102,8 @@ namespace FUSE
   int
   release(const fuse_file_info_t *ffi_)
   {
-    Config::Read cfg;
-    FileInfo *fi = reinterpret_cast<FileInfo*>(ffi_->fh);
+    const fuse_context *fc = fuse_get_context();
 
-    return l::release(fi,cfg->dropcacheonclose);
+    return ::_release(fc,ffi_);
   }
 }