Simplify lowlevel fuse state management and req mem

libfuse/include/fuse.h

@@ -150,7 +150,7 @@ struct fuse_operations
   int (*fsyncdir)(const fuse_req_ctx_t *,
                   const fuse_file_info_t *,
                   int);
-  void *(*init)(struct fuse_conn_info *conn);
+  void *(*init)(fuse_conn_info_t *conn);
   void (*destroy)(void);
   int (*access)(const fuse_req_ctx_t *,
                 const char *,

libfuse/include/fuse_common.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "extern_c.h"
+#include "fuse_conn_info.hpp"
 #include "fuse_opt.h"
 #include "fuse_timeouts.h"
 
@@ -76,7 +77,7 @@ struct fuse_file_info_t
 };
 
 /**
- * Capability bits for 'fuse_conn_info.capable' and 'fuse_conn_info.want'
+ * Capability bits for 'fuse_conn_info_t.capable' and 'fuse_conn_info_t.want'
  *
  * FUSE_CAP_ASYNC_READ: filesystem supports asynchronous read requests
  * FUSE_CAP_POSIX_LOCKS: filesystem supports "remote" locking
@@ -128,21 +129,6 @@ struct fuse_file_info_t
 
 #define FUSE_IOCTL_MAX_IOV	256
 
-/**
- * Connection information, passed to the ->init() method
- *
- * Some of the elements are read-write, these can be changed to
- * indicate the value requested by the filesystem.  The requested
- * value must usually be smaller than the indicated value.
- */
-struct fuse_conn_info
-{
-  unsigned proto_major;
-  unsigned proto_minor;
-  uint64_t capable;
-  uint64_t want;
-};
-
 struct fuse_session;
 struct fuse_chan;
 struct fuse_pollhandle_t;

libfuse/include/fuse_conn_info.hpp

@@ -0,0 +1,12 @@
+#pragma once
+
+#include "base_types.h"
+
+typedef struct fuse_conn_info_t fuse_conn_info_t;
+struct fuse_conn_info_t
+{
+  u32 proto_major;
+  u32 proto_minor;
+  u64 capable;
+  u64 want;
+};

libfuse/include/fuse_lowlevel.h

@@ -3,7 +3,7 @@
 #include "extern_c.h"
 #include "fuse_common.h"
 #include "fuse_kernel.h"
-#include "fuse_req.h"
+#include "fuse_req.hpp"
 
 #include <fcntl.h>
 #include <stdint.h>
@@ -119,7 +119,7 @@ struct fuse_lowlevel_ops
   void (*getattr)(fuse_req_t *req, struct fuse_in_header *hdr);
   void (*getlk)(fuse_req_t *req, const struct fuse_in_header *hdr);
   void (*getxattr)(fuse_req_t *req, struct fuse_in_header *hdr);
-  void (*init)(void *userdata, struct fuse_conn_info *conn);
+  void (*init)(void *userdata, fuse_conn_info_t *conn);
   void (*ioctl)(fuse_req_t *req, const struct fuse_in_header *hdr);
   void (*link)(fuse_req_t *req, struct fuse_in_header *hdr);
   void (*listxattr)(fuse_req_t *req, struct fuse_in_header *hdr);

libfuse/include/fuse_pollhandle.h

@@ -3,12 +3,10 @@
 #include <stdint.h>
 
 struct fuse_chan;
-struct fuse_ll;
 
 typedef struct fuse_pollhandle_t fuse_pollhandle_t;
 struct fuse_pollhandle_t
 {
   uint64_t kh;
   struct fuse_chan *ch;
-  struct fuse_ll *f;
 };

libfuse/include/fuse_req.hpp

@@ -1,15 +1,18 @@
 #pragma once
 
 #include "fuse_req_ctx.h"
+#include "fuse_conn_info.hpp"
 
-struct fuse_ll;
 struct fuse_chan;
 
 typedef struct fuse_req_t fuse_req_t;
 struct fuse_req_t
 {
   fuse_req_ctx_t ctx;
-  struct fuse_ll *f;
   struct fuse_chan *ch;
+  fuse_conn_info_t conn;
   unsigned int ioctl_64bit : 1;
 };
+
+fuse_req_t* fuse_req_alloc();
+void fuse_req_free(fuse_req_t*);

libfuse/include/objpool.hpp

@@ -0,0 +1,136 @@
+/*
+  ISC License
+
+  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.
+*/
+
+#pragma once
+
+#include <mutex>
+#include <new>
+#include <utility>
+#include <type_traits>
+
+template<typename T>
+class ObjPool
+{
+private:
+  struct alignas(alignof(T)) Node
+  {
+    Node *next;
+  };
+
+private:
+  static_assert(sizeof(T) >= sizeof(Node), "T must be at least pointer-sized");
+  static_assert(std::is_nothrow_destructible_v<T>, "T must be nothrow destructible");
+
+private:
+  static
+  Node*
+  to_node(T *obj_)
+  {
+    return reinterpret_cast<Node*>(obj_);
+  }
+
+private:
+  std::mutex _mtx;
+  Node *_head = nullptr;
+
+public:
+  ObjPool() = default;
+  ObjPool(const ObjPool&) = delete;
+  ObjPool& operator=(const ObjPool&) = delete;
+  ObjPool(ObjPool&&) = delete;
+  ObjPool& operator=(ObjPool&&) = delete;
+
+  ~ObjPool()
+  {
+    clear();
+  }
+
+private:
+  Node*
+  _pop_node()
+  {
+    std::lock_guard<std::mutex> lock(_mtx);
+
+    Node *node = _head;
+    if(node)
+      _head = node->next;
+
+    return node;
+  }
+
+  void
+  _push_node(Node *node_)
+  {
+    std::lock_guard<std::mutex> lock(_mtx);
+
+    node_->next = _head;
+    _head = node_;
+  }
+
+public:
+  void
+  clear() noexcept
+  {
+    Node *head;
+
+    {
+      std::lock_guard<std::mutex> lock(_mtx);
+      head  = _head;
+      _head = nullptr;
+    }
+
+    while(head)
+      {
+        Node *next = head->next;
+        ::operator delete(head, std::align_val_t{alignof(T)});
+        head = next;
+      }
+  }
+
+  template<typename... Args>
+  T*
+  alloc(Args&&... args_)
+  {
+    void *mem;
+    Node *node;
+
+    node = _pop_node();
+    mem  = (node ?
+            static_cast<void*>(node) :
+            ::operator new(sizeof(T), std::align_val_t{alignof(T)}));
+
+    try
+      {
+        return new(mem) T(std::forward<Args>(args_)...);
+      }
+    catch(...)
+      {
+        _push_node(static_cast<Node*>(mem));
+        throw;
+      }
+  }
+
+  void
+  free(T *obj_) noexcept
+  {
+    if(not obj_)
+      return;
+
+    obj_->~T();
+
+    _push_node(to_node(obj_));
+  }
+};

libfuse/lib/fuse.cpp

@@ -21,7 +21,7 @@
 #include "node.hpp"
 
 #include "fuse_cfg.hpp"
-#include "fuse_req.h"
+#include "fuse_req.hpp"
 #include "fuse_dirents.hpp"
 #include "fuse_i.h"
 #include "fuse_kernel.h"
@@ -1323,8 +1323,8 @@ reply_entry(fuse_req_t                    *req_,
 
 static
 void
-fuse_lib_init(void                  *data,
-              struct fuse_conn_info *conn)
+fuse_lib_init(void             *data,
+              fuse_conn_info_t *conn)
 {
   f.ops.init(conn);
 }
@@ -1747,7 +1747,7 @@ fuse_lib_mknod(fuse_req_t            *req_,
   arg  = (fuse_mknod_in*)fuse_hdr_arg(hdr_);
   name = (const char*)PARAM(arg);
 
-  if(req_->f->conn.proto_minor >= 12)
+  if(req_->conn.proto_minor >= 12)
     req_->ctx.umask = arg->umask;
   else
     name = (char*)arg + FUSE_COMPAT_MKNOD_IN_SIZE;
@@ -1803,7 +1803,7 @@ fuse_lib_mkdir(fuse_req_t            *req_,
 
   arg  = (fuse_mkdir_in*)fuse_hdr_arg(hdr_);
   name = (const char*)PARAM(arg);
-  if(req_->f->conn.proto_minor >= 12)
+  if(req_->conn.proto_minor >= 12)
     req_->ctx.umask = arg->umask;
 
   err = get_path_name(hdr_->nodeid,name,&fusepath);
@@ -2040,7 +2040,7 @@ fuse_lib_create(fuse_req_t            *req_,
 
   ffi.flags = arg->flags;
 
-  if(req_->f->conn.proto_minor >= 12)
+  if(req_->conn.proto_minor >= 12)
     req_->ctx.umask = arg->umask;
   else
     name = ((char*)arg + sizeof(struct fuse_open_in));
@@ -2194,7 +2194,7 @@ fuse_lib_read(fuse_req_t            *req_,
 
   arg = (fuse_read_in*)fuse_hdr_arg(hdr_);
   ffi.fh = arg->fh;
-  if(req_->f->conn.proto_minor >= 9)
+  if(req_->conn.proto_minor >= 9)
     {
       ffi.flags      = arg->flags;
       ffi.lock_owner = arg->lock_owner;
@@ -2229,7 +2229,7 @@ fuse_lib_write(fuse_req_t            *req_,
   arg     = (fuse_write_in*)fuse_hdr_arg(hdr_);
   ffi.fh  = arg->fh;
   ffi.writepage = !!(arg->write_flags & 1);
-  if(req_->f->conn.proto_minor < 9)
+  if(req_->conn.proto_minor < 9)
     {
       data = ((char*)arg) + FUSE_COMPAT_WRITE_IN_SIZE;
     }
@@ -2549,8 +2549,8 @@ fuse_lib_setxattr(fuse_req_t            *req_,
   struct fuse_setxattr_in *arg;
 
   arg = (fuse_setxattr_in*)fuse_hdr_arg(hdr_);
-  if((req_->f->conn.capable & FUSE_SETXATTR_EXT) &&
-     (req_->f->conn.want & FUSE_SETXATTR_EXT))
+  if((req_->conn.capable & FUSE_SETXATTR_EXT) &&
+     (req_->conn.want & FUSE_SETXATTR_EXT))
     name = (const char*)PARAM(arg);
   else
     name = (((char*)arg) + FUSE_COMPAT_SETXATTR_IN_SIZE);
@@ -2791,7 +2791,7 @@ fuse_lib_tmpfile(fuse_req_t                  *req_,
 
   ffi.flags = arg->flags;
 
-  if(req_->f->conn.proto_minor >= 12)
+  if(req_->conn.proto_minor >= 12)
     req_->ctx.umask = arg->umask;
   else
     name = (char*)arg + sizeof(struct fuse_open_in);
@@ -3035,7 +3035,7 @@ fuse_lib_release(fuse_req_t            *req_,
   arg = (fuse_release_in*)fuse_hdr_arg(hdr_);
   ffi.fh    = arg->fh;
   ffi.flags = arg->flags;
-  if(req_->f->conn.proto_minor >= 8)
+  if(req_->conn.proto_minor >= 8)
     {
       ffi.flush      = !!(arg->release_flags & FUSE_RELEASE_FLUSH);
       ffi.lock_owner = arg->lock_owner;
@@ -3073,7 +3073,7 @@ fuse_lib_flush(fuse_req_t             *req_,
 
   ffi.fh = arg->fh;
   ffi.flush = 1;
-  if(req_->f->conn.proto_minor >= 7)
+  if(req_->conn.proto_minor >= 7)
     ffi.lock_owner = arg->lock_owner;
 
   err = fuse_flush_common(req_,hdr_->nodeid,&ffi);
@@ -3233,14 +3233,14 @@ fuse_lib_ioctl(fuse_req_t                  *req_,
   const struct fuse_ioctl_in *arg;
 
   arg = (fuse_ioctl_in*)fuse_hdr_arg(hdr_);
-  if((arg->flags & FUSE_IOCTL_DIR) && !(req_->f->conn.want & FUSE_CAP_IOCTL_DIR))
+  if((arg->flags & FUSE_IOCTL_DIR) && !(req_->conn.want & FUSE_CAP_IOCTL_DIR))
     {
       fuse_reply_err(req_,ENOTTY);
       return;
     }
 
   if((sizeof(void*) == 4)              &&
-     (req_->f->conn.proto_minor >= 16) &&
+     (req_->conn.proto_minor >= 16) &&
      !(arg->flags & FUSE_IOCTL_32BIT))
     {
       req_->ioctl_64bit = 1;
@@ -3314,7 +3314,6 @@ fuse_lib_poll(fuse_req_t                  *req_,
 
       ph->kh = arg->kh;
       ph->ch = req_->ch;
-      ph->f  = req_->f;
     }
 
   err = f.ops.poll(&req_->ctx,

libfuse/lib/fuse_i.h

@@ -43,19 +43,6 @@ struct fuse_notify_req
   struct fuse_notify_req *prev;
 };
 
-struct fuse_ll
-{
-  struct fuse_lowlevel_ops op;
-  void *userdata;
-  uid_t owner;
-  struct fuse_conn_info conn;
-  pthread_mutex_t lock;
-  int got_init;
-  int got_destroy;
-  uint64_t notify_ctr;
-  struct fuse_notify_req notify_list;
-};
-
 struct fuse_cmd
 {
   char *buf;
@@ -80,11 +67,6 @@ int fuse_chan_clearfd(struct fuse_chan *ch);
 void fuse_kern_unmount(const char *mountpoint, int fd);
 int fuse_kern_mount(const char *mountpoint, struct fuse_args *args);
 
-int fuse_send_reply_iov_nofree(fuse_req_t req, int error, struct iovec *iov,
-			       int count);
-void fuse_free_req(fuse_req_t req);
-
-
 struct fuse *fuse_setup_common(int argc,
                                char *argv[],
 			       const struct fuse_operations *op,

libfuse/lib/fuse_loop.cpp

@@ -16,7 +16,6 @@
 
 #include "fuse_cfg.hpp"
 #include "fuse_msgbuf.hpp"
-#include "fuse_ll.hpp"
 
 #include <cassert>
 #include <memory>

libfuse/lib/fuse_req.cpp

@@ -0,0 +1,18 @@
+#include "fuse_req.hpp"
+
+#include "objpool.hpp"
+
+
+static ObjPool<fuse_req_t> g_pool;
+
+fuse_req_t*
+fuse_req_alloc()
+{
+  return g_pool.alloc();
+}
+
+void
+fuse_req_free(fuse_req_t *req_)
+{
+  return g_pool.free(req_);
+}

src/fuse_init.cpp

@@ -35,7 +35,7 @@
 
 static
 void
-_want(fuse_conn_info *conn_,
+_want(fuse_conn_info_t *conn_,
       const int       flag_)
 {
   conn_->want |= flag_;
@@ -43,7 +43,7 @@ _want(fuse_conn_info *conn_,
 
 static
 bool
-_capable(fuse_conn_info *conn_,
+_capable(fuse_conn_info_t *conn_,
          const int       flag_)
 {
   return !!(conn_->capable & flag_);
@@ -51,7 +51,7 @@ _capable(fuse_conn_info *conn_,
 
 static
 void
-_want_if_capable(fuse_conn_info *conn_,
+_want_if_capable(fuse_conn_info_t *conn_,
                  const int       flag_)
 {
   if(::_capable(conn_,flag_))
@@ -60,7 +60,7 @@ _want_if_capable(fuse_conn_info *conn_,
 
 static
 void
-_want_if_capable(fuse_conn_info *conn_,
+_want_if_capable(fuse_conn_info_t *conn_,
                  const int       flag_,
                  ConfigBOOL     *want_)
 {
@@ -78,7 +78,7 @@ static const char MAX_PAGES_LIMIT_FILEPATH[] = "/proc/sys/fs/fuse/max_pages_limi
 
 static
 void
-_want_if_capable_max_pages(fuse_conn_info *conn_,
+_want_if_capable_max_pages(fuse_conn_info_t *conn_,
                            Config         &cfg_)
 {
   std::fstream f;
@@ -184,7 +184,7 @@ _spawn_thread_to_set_readahead()
 }
 
 void *
-FUSE::init(fuse_conn_info *conn_)
+FUSE::init(fuse_conn_info_t *conn_)
 {
   procfs::init();
   cfg.readdir.initialize();

src/fuse_init.hpp

@@ -22,5 +22,5 @@
 namespace FUSE
 {
   void *
-  init(fuse_conn_info *conn);
+  init(fuse_conn_info_t *conn);
 }