Move fuse_session to C++ and make exit flag atomic

vendored/libfuse/Makefile

@@ -79,7 +79,6 @@ BUILDDIR := build
 SRC_C = \
 	lib/crc32b.c \
 	lib/fuse_opt.c \
-	lib/fuse_session.c \
 	lib/fuse_signals.c \
 	lib/helper.c \
 	lib/mount.c

vendored/libfuse/lib/fuse.cpp

@@ -22,7 +22,7 @@
 #include "fuse_cfg.hpp"
 #include "fuse_req.hpp"
 #include "fuse_dirents.hpp"
-#include "fuse_i.h"
+#include "fuse_i.hpp"
 #include "fuse_kernel.h"
 #include "fuse_lowlevel.h"
 #include "fuse_opt.h"

vendored/libfuse/lib/fuse_i.hpp

@@ -14,7 +14,7 @@
 
 #include "extern_c.h"
 
-#include <signal.h>
+#include <atomic>
 
 /* Simplified fuse_session - fields inlined from former fuse_chan
  * Since mergerfs only supports one mount, we collapse the hierarchy:
@@ -32,7 +32,7 @@ struct fuse_session
   void (*destroy)(void *data);
 
   struct fuse_ll *f;
-  volatile sig_atomic_t exited;
+  std::atomic<int> exited;
 
   /* Formerly in fuse_chan - inlined for single-mount simplicity */
   int fd;            /* /dev/fuse file descriptor */
@@ -58,11 +58,4 @@ struct fuse_session *fuse_lowlevel_new_common(struct fuse_args *args,
                                               const struct fuse_lowlevel_ops *op,
                                               size_t op_size, void *userdata);
 
-
-
-void fuse_kern_unmount(const char *mountpoint, int fd);
-int fuse_kern_mount(const char *mountpoint, struct fuse_args *args);
-
-int fuse_start_thread(pthread_t *thread_id, void *(*func)(void *), void *arg);
-
 EXTERN_C_END

vendored/libfuse/lib/fuse_loop.cpp

@@ -10,7 +10,7 @@
 #include "syslog.hpp"
 #include "maintenance_thread.hpp"
 
-#include "fuse_i.h"
+#include "fuse_i.hpp"
 #include "fuse_kernel.h"
 #include "fuse_lowlevel.h"
 

vendored/libfuse/lib/fuse_lowlevel.cpp

@@ -16,7 +16,7 @@
 #include "fatal.hpp"
 #include "fmt/core.h"
 #include "fuse_cfg.hpp"
-#include "fuse_i.h"
+#include "fuse_i.hpp"
 #include "fuse_kernel.h"
 #include "fuse_msgbuf.hpp"
 #include "fuse_opt.h"

vendored/libfuse/lib/fuse_session.cpp

@@ -4,16 +4,16 @@
 
   This program can be distributed under the terms of the GNU LGPLv2.
   See the file COPYING.LIB
- */
+*/
 
-#include "fuse_i.h"
+#include "fuse_i.hpp"
 #include "fuse_kernel.h"
 
-#include <assert.h>
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
+#include <cassert>
+#include <cerrno>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <unistd.h>
 #include <sys/uio.h>
 
@@ -30,19 +30,19 @@ fuse_session_new(void *data,
                  void *process_buf,
                  void *destroy)
 {
-  struct fuse_session *se = (struct fuse_session *) malloc(sizeof(*se));
-  if (se == NULL) {
-    fprintf(stderr, "fuse: failed to allocate session\n");
-    return NULL;
-  }
+  auto *se = new(std::nothrow) fuse_session();
 
-  memset(se, 0, sizeof(*se));
-  se->f           = data;
-  se->receive_buf = receive_buf;
-  se->process_buf = process_buf;
-  se->destroy     = destroy;
-  se->fd          = -1;  /* Not yet mounted */
-  //se->bufsize     = 0;
+  if(se == nullptr)
+    {
+      fprintf(stderr, "fuse: failed to allocate session\n");
+      return nullptr;
+    }
+
+  se->f           = static_cast<struct fuse_ll*>(data);
+  se->receive_buf = reinterpret_cast<int(*)(struct fuse_session*, fuse_msgbuf_t*)>(receive_buf);
+  se->process_buf = reinterpret_cast<void(*)(struct fuse_session*, const fuse_msgbuf_t*)>(process_buf);
+  se->destroy     = reinterpret_cast<void(*)(void*)>(destroy);
+  se->fd          = -1;
 
   return se;
 }
@@ -50,12 +50,16 @@ fuse_session_new(void *data,
 void
 fuse_session_destroy(struct fuse_session *se)
 {
-  se->destroy(se->f);
-  if(se->fd != -1) {
-    close(se->fd);
-    se->fd = -1;
-  }
-  free(se);
+  if(se->destroy)
+    se->destroy(se->f);
+
+  if(se->fd != -1)
+    {
+      close(se->fd);
+      se->fd = -1;
+    }
+
+  delete se;
 }
 
 void
@@ -103,3 +107,15 @@ fuse_session_setbufsize(struct fuse_session *se,
 {
   se->bufsize = bufsize;
 }
+
+int
+fuse_session_fd(struct fuse_session *se)
+{
+  return se->fd;
+}
+
+size_t
+fuse_session_bufsize(struct fuse_session *se)
+{
+  return se->bufsize;
+}

vendored/libfuse/lib/helper.c

@@ -6,7 +6,7 @@
   See the file COPYING.LIB.
 */
 
-#include "fuse_i.h"
+#include "fuse.h"
 #include "fuse_opt.h"
 #include "fuse_lowlevel.h"
 
@@ -19,6 +19,9 @@
 #include <errno.h>
 #include <sys/param.h>
 
+int fuse_kern_mount(const char *mountpoint, struct fuse_args *args);
+void fuse_kern_unmount(const char *mountpoint, int fd);
+
 enum  {
   KEY_HELP,
   KEY_HELP_NOHEADER,
@@ -312,10 +315,10 @@ struct fuse *fuse_setup(int argc,
 static void fuse_teardown_common(char *mountpoint)
 {
   struct fuse_session *se = fuse_get_session();
-  int fd = se ? se->fd : -1;
+  int fd = se ? fuse_session_fd(se) : -1;
   fuse_remove_signal_handlers(se);
   if (mountpoint && fd != -1) {
-    se->fd = -1;
+    fuse_session_clearfd(se);
     fuse_kern_unmount(mountpoint, fd);
   }
   free(mountpoint);

vendored/libfuse/lib/mount_bsd.c

@@ -6,7 +6,6 @@
   See the file COPYING.LIB.
 */
 
-#include "fuse_i.h"
 #include "fuse_opt.h"
 
 #include <sys/stat.h>

vendored/libfuse/lib/mount_generic.c

@@ -6,7 +6,6 @@
   See the file COPYING.LIB.
 */
 
-#include "fuse_i.h"
 #include "fuse_opt.h"
 #include "mount_util.h"
 
@@ -19,6 +18,7 @@
 #include <errno.h>
 #include <poll.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
 #include <sys/un.h>
 #include <sys/wait.h>
 #include <sys/mount.h>