use temp files (then rename) when moving files for moveonenospc

src/fs.cpp

@@ -218,6 +218,13 @@ namespace fs
     return ::fcntl(fd,F_GETFL,0);
   }
 
+  int
+  setfl(const int    fd,
+        const mode_t mode)
+  {
+    return ::fcntl(fd,F_SETFL,mode);
+  }
+
   int
   mfs(const vector<string> &basepaths,
       const uint64_t        minfreespace,

src/fs.hpp

@@ -20,6 +20,7 @@
 #include <string>
 #include <vector>
 
+#include <fcntl.h>
 #include <stdint.h>
 
 namespace fs
@@ -59,6 +60,8 @@ namespace fs
   void realpathize(vector<string> &strs);
 
   int getfl(const int fd);
+  int setfl(const int    fd,
+            const mode_t mode);
 
   int mfs(const vector<string> &srcs,
           const uint64_t        minfreespace,

src/fs_base_mkstemp.hpp

@@ -0,0 +1,50 @@
+/*
+  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.
+*/
+
+#ifndef __FS_BASE_MKSTEMP_HPP__
+#define __FS_BASE_MKSTEMP_HPP__
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <string>
+
+namespace fs
+{
+  static
+  inline
+  int
+  mkstemp(std::string &filepath)
+  {
+    int fd;
+    char buf[filepath.size()+8];
+
+    strcpy(buf,filepath.c_str());
+    strcpy(buf+filepath.size(),".XXXXXX");
+
+    fd = ::mkstemp(buf);
+    if(fd == -1)
+      return -1;
+
+    filepath = buf;
+
+    return fd;
+  }
+}
+
+#endif

src/fs_movefile.cpp

@@ -15,6 +15,7 @@
 */
 
 #include <fcntl.h>
+#include <stdlib.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -22,9 +23,12 @@
 #include <string>
 #include <vector>
 
+#include "errno.hpp"
 #include "fs.hpp"
 #include "fs_base_open.hpp"
 #include "fs_base_close.hpp"
+#include "fs_base_mkstemp.hpp"
+#include "fs_base_rename.hpp"
 #include "fs_base_unlink.hpp"
 #include "fs_base_stat.hpp"
 #include "fs_clonefile.hpp"
@@ -49,6 +53,7 @@ namespace fs
     string fusedir;
     string fdin_path;
     string fdout_path;
+    string fdout_temp;
     struct stat fdin_st;
 
     fdin = origfd;
@@ -82,18 +87,22 @@ namespace fs
       return -1;
 
     fs::path::append(fdout_path,fusepath);
-    fdout = fs::open(fdout_path,fdin_flags|O_CREAT,fdin_st.st_mode);
+    fdout_temp = fdout_path;
+    fdout = fs::mkstemp(fdout_temp);
     if(fdout == -1)
       return -1;
 
     rv = fs::clonefile(fdin,fdout);
     if(rv == -1)
-      {
-        fs::close(fdin);
-        fs::close(fdout);
-        fs::unlink(fdout_path);
-        return -1;
-      }
+      goto cleanup;
+
+    rv = fs::setfl(fdout,fdin_flags);
+    if(rv == -1)
+      goto cleanup;
+
+    rv = fs::rename(fdout_temp,fdout_path);
+    if(rv == -1)
+      goto cleanup;
 
     // should we care if it fails?
     fs::unlink(fdin_path);
@@ -103,5 +112,15 @@ namespace fs
     fs::close(fdout);
 
     return 0;
+
+  cleanup:
+    rv = errno;
+    if(fdin != -1)
+      fs::close(fdin);
+    if(fdout != -1)
+      fs::close(fdout);
+    fs::unlink(fdout_temp);
+    errno = rv;
+    return -1;
   }
 }