initial code commit

src/write.cpp

@@ -0,0 +1,163 @@
+/*
+   The MIT License (MIT)
+
+   Copyright (c) 2014 Antonio SJ Musumeci <trapexit@spawn.link>
+
+   Permission is hereby granted, free of charge, to any person obtaining a copy
+   of this software and associated documentation files (the "Software"), to deal
+   in the Software without restriction, including without limitation the rights
+   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+   copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+   THE SOFTWARE.
+*/
+
+#include <fuse.h>
+
+#include <errno.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+#include <sstream>
+
+#include "config.hpp"
+#include "policy.hpp"
+#include "ugid.hpp"
+#include "fileinfo.hpp"
+
+using mergerfs::config::Config;
+using mergerfs::Policy;
+using std::string;
+using std::vector;
+using std::stringstream;
+
+static
+int
+_process_kv(Config       &config,
+            const string  key,
+            const string  value)
+{
+  int rv = 0;
+
+  if(key == "search")
+    {
+      rv = (Policy::Search::fromString(value) != -1) ? 0 : -EINVAL;
+      if(rv == 0)
+        config.policy.search = value;
+    }
+  else if(key == "action")
+    {
+      rv = (Policy::Action::fromString(value) != -1) ? 0 : -EINVAL;
+      if(rv == 0)
+        config.policy.action = value;
+    }
+  else if(key == "create")
+    {
+      rv = (Policy::Create::fromString(value) != -1) ? 0 : -EINVAL;
+      if(rv == 0)
+        config.policy.create = value;
+    }
+  else if(key == "statfs")
+    {
+      rv = (Policy::StatFS::fromString(value) != -1) ? 0 : -EINVAL;
+      if(rv == 0)
+        config.policy.statfs = value;
+    }
+  else
+    {
+      rv = -EINVAL;
+    }
+
+  if(rv == 0)
+    config.updateReadStr();
+
+  return rv;
+}
+
+static
+int
+_write_controlfile(Config       &config,
+                   string       &existing,
+                   const string  buf,
+                   const off_t   _offset)
+{
+  size_t bufsize      = buf.size();
+  size_t existingsize = existing.size();
+
+  if((existingsize + buf.size()) > 1024)
+    return (existing.clear(),-EINVAL);
+
+  existing += buf;
+
+  size_t nlpos = existing.find_first_of('\n',existingsize);
+  if(nlpos == string::npos)
+    return 0;
+
+  string line = existing.substr(0,nlpos);
+  existing = existing.substr(nlpos+1);
+
+  size_t equalsoffset = line.find_first_of('=');
+  if(equalsoffset == string::npos)
+    return -EINVAL;
+
+  int rv;
+  string key   = line.substr(0,equalsoffset);
+  string value = line.substr(equalsoffset+1);
+
+  rv = _process_kv(config,key,value);
+
+  return ((rv < 0) ? rv : bufsize);
+}
+
+static
+int
+_write(const int     fd,
+       const void   *buf,
+       const size_t  count,
+       const off_t   offset)
+{
+  int rv;
+
+  rv = ::pwrite(fd,buf,count,offset);
+
+  return ((rv == -1) ? -errno : rv);
+}
+
+namespace mergerfs
+{
+  namespace write
+  {
+    int
+    write(const char            *fusepath,
+          const char            *buf,
+          size_t                 count,
+          off_t                  offset,
+          struct fuse_file_info *fi)
+    {
+      const ugid::SetResetGuard  ugid;
+      const config::Config      &config   = config::get();
+
+      if(fusepath == config.controlfile)
+        return _write_controlfile(config::get_writable(),
+                                  *(string*)fi->fh,
+                                  string(buf,count),
+                                  offset);
+
+      return _write(((FileInfo*)fi->fh)->fd,
+                    buf,
+                    count,
+                    offset);
+    }
+  }
+}