fs: Add file_pipe function

so pty don't need call nx_pipe and then file_detach

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: Ibb8d108abd76bafe53897e5fca35babcf3e1bae9

drivers/pipes/pipe.c

@@ -158,6 +158,83 @@ static int pipe_close(FAR struct file *filep)
   return ret;
 }
 
+/****************************************************************************
+ * Name: pipe_register
+ ****************************************************************************/
+
+static int pipe_register(size_t bufsize, int flags,
+                         FAR char *devname, size_t namesize)
+{
+  FAR struct pipe_dev_s *dev;
+  int pipeno;
+  int ret;
+
+  /* Get exclusive access to the pipe allocation data */
+
+  ret = nxsem_wait(&g_pipesem);
+  if (ret < 0)
+    {
+      goto errout;
+    }
+
+  /* Allocate a minor number for the pipe device */
+
+  pipeno = pipe_allocate();
+  if (pipeno < 0)
+    {
+      ret = pipeno;
+      goto errout_with_sem;
+    }
+
+  /* Create a pathname to the pipe device */
+
+  snprintf(devname, namesize, "/dev/pipe%d", pipeno);
+
+  /* Check if the pipe device has already been created */
+
+  if ((g_pipecreated & (1 << pipeno)) == 0)
+    {
+      /* No.. Allocate and initialize a new device structure instance */
+
+      dev = pipecommon_allocdev(bufsize);
+      if (!dev)
+        {
+          ret = -ENOMEM;
+          goto errout_with_pipe;
+        }
+
+      dev->d_pipeno = pipeno;
+
+      /* Register the pipe device */
+
+      ret = register_driver(devname, &pipe_fops, 0666, (FAR void *)dev);
+      if (ret != 0)
+        {
+          nxsem_post(&g_pipesem);
+          goto errout_with_dev;
+        }
+
+      /* Remember that we created this device */
+
+       g_pipecreated |= (1 << pipeno);
+    }
+
+  nxsem_post(&g_pipesem);
+  return OK;
+
+errout_with_dev:
+  pipecommon_freedev(dev);
+
+errout_with_pipe:
+  pipe_free(pipeno);
+
+errout_with_sem:
+  nxsem_post(&g_pipesem);
+
+errout:
+  return ret;
+}
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -186,66 +263,57 @@ static int pipe_close(FAR struct file *filep)
  *
  ****************************************************************************/
 
-int nx_pipe(int fd[2], size_t bufsize, int flags)
+int file_pipe(FAR struct file *filep[2], size_t bufsize, int flags)
 {
-  FAR struct pipe_dev_s *dev = NULL;
   char devname[16];
-  int pipeno;
   int ret;
 
-  /* Get exclusive access to the pipe allocation data */
+  /* Register a new pipe device */
 
-  ret = nxsem_wait(&g_pipesem);
+  ret = pipe_register(bufsize, flags, devname, sizeof(devname));
   if (ret < 0)
     {
-      goto errout;
+      return ret;
     }
 
-  /* Allocate a minor number for the pipe device */
+  /* Get a write file descriptor */
 
-  pipeno = pipe_allocate();
+  ret = file_open(filep[1], devname, O_WRONLY | flags);
-  if (pipeno < 0)
+  if (ret < 0)
     {
-      nxsem_post(&g_pipesem);
+      goto errout_with_driver;
-      ret = pipeno;
-      goto errout;
     }
 
-  /* Create a pathname to the pipe device */
+  /* Get a read file descriptor */
 
-  snprintf(devname, sizeof(devname), "/dev/pipe%d", pipeno);
+  ret = file_open(filep[0], devname, O_RDONLY | flags);
-
+  if (ret < 0)
-  /* Check if the pipe device has already been created */
-
-  if ((g_pipecreated & (1 << pipeno)) == 0)
     {
-      /* No.. Allocate and initialize a new device structure instance */
+      goto errout_with_wrfd;
-
-      dev = pipecommon_allocdev(bufsize);
-      if (!dev)
-        {
-          nxsem_post(&g_pipesem);
-          ret = -ENOMEM;
-          goto errout_with_pipe;
-        }
-
-      dev->d_pipeno = pipeno;
-
-      /* Register the pipe device */
-
-      ret = register_driver(devname, &pipe_fops, 0666, (FAR void *)dev);
-      if (ret != 0)
-        {
-          nxsem_post(&g_pipesem);
-          goto errout_with_dev;
-        }
-
-      /* Remember that we created this device */
-
-       g_pipecreated |= (1 << pipeno);
     }
 
-  nxsem_post(&g_pipesem);
+  return OK;
+
+errout_with_wrfd:
+  file_close(filep[1]);
+
+errout_with_driver:
+  unregister_driver(devname);
+  return ret;
+}
+
+int nx_pipe(int fd[2], size_t bufsize, int flags)
+{
+  char devname[16];
+  int ret;
+
+  /* Register a new pipe device */
+
+  ret = pipe_register(bufsize, flags, devname, sizeof(devname));
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* Get a write file descriptor */
 
@@ -272,17 +340,6 @@ errout_with_wrfd:
 
 errout_with_driver:
   unregister_driver(devname);
-
-errout_with_dev:
-  if (dev)
-    {
-      pipecommon_freedev(dev);
-    }
-
-errout_with_pipe:
-  pipe_free(pipeno);
-
-errout:
   return ret;
 }
 

drivers/serial/pty.c

@@ -1080,8 +1080,8 @@ static int pty_unlink(FAR struct inode *inode)
 int pty_register(int minor)
 {
   FAR struct pty_devpair_s *devpair;
-  int pipe_a[2];
+  FAR struct file *pipe_a[2];
-  int pipe_b[2];
+  FAR struct file *pipe_b[2];
   char devname[16];
   int ret;
 
@@ -1118,56 +1118,24 @@ int pty_register(int minor)
    *   pipe_b:  Master sink, slave source (RX, master-to-slave)
    */
 
-  ret = nx_pipe(pipe_a, CONFIG_PSEUDOTERM_TXBUFSIZE, 0);
+  pipe_a[0] = &devpair->pp_master.pd_src;
+  pipe_a[1] = &devpair->pp_slave.pd_sink;
+
+  ret = file_pipe(pipe_a, CONFIG_PSEUDOTERM_TXBUFSIZE, 0);
   if (ret < 0)
     {
       goto errout_with_devpair;
     }
 
-  ret = nx_pipe(pipe_b, CONFIG_PSEUDOTERM_RXBUFSIZE, 0);
+  pipe_b[0] = &devpair->pp_slave.pd_src;
+  pipe_b[1] = &devpair->pp_master.pd_sink;
+
+  ret = file_pipe(pipe_b, CONFIG_PSEUDOTERM_RXBUFSIZE, 0);
   if (ret < 0)
     {
       goto errout_with_pipea;
     }
 
-  /* Detach the pipe file descriptors (closing them in the process)
-   *
-   *  fd[0] is for reading;
-   *  fd[1] is for writing.
-   */
-
-  ret = file_detach(pipe_a[0], &devpair->pp_master.pd_src);
-  if (ret < 0)
-    {
-      goto errout_with_pipeb;
-    }
-
-  pipe_a[0] = -1;
-
-  ret = file_detach(pipe_a[1], &devpair->pp_slave.pd_sink);
-  if (ret < 0)
-    {
-      goto errout_with_pipeb;
-    }
-
-  pipe_a[1] = -1;
-
-  ret = file_detach(pipe_b[0], &devpair->pp_slave.pd_src);
-  if (ret < 0)
-    {
-      goto errout_with_pipeb;
-    }
-
-  pipe_b[0] = -1;
-
-  ret = file_detach(pipe_b[1], &devpair->pp_master.pd_sink);
-  if (ret < 0)
-    {
-      goto errout_with_pipeb;
-    }
-
-  pipe_b[1] = -1;
-
   /* Register the slave device
    *
    * BSD style (deprecated): /dev/ttypN
@@ -1215,42 +1183,12 @@ errout_with_slave:
   unregister_driver(devname);
 
 errout_with_pipeb:
-  if (pipe_b[0] >= 0)
+  file_close(pipe_b[0]);
-    {
+  file_close(pipe_b[1]);
-      close(pipe_b[0]);
-    }
-  else
-    {
-      file_close(&devpair->pp_master.pd_src);
-    }
-
-  if (pipe_b[1] >= 0)
-    {
-      close(pipe_b[1]);
-    }
-  else
-    {
-      file_close(&devpair->pp_slave.pd_sink);
-    }
 
 errout_with_pipea:
-  if (pipe_a[0] >= 0)
+  file_close(pipe_a[0]);
-    {
+  file_close(pipe_a[1]);
-      close(pipe_a[0]);
-    }
-  else
-    {
-      file_close(&devpair->pp_slave.pd_src);
-    }
-
-  if (pipe_a[1] >= 0)
-    {
-      close(pipe_a[1]);
-    }
-  else
-    {
-      file_close(&devpair->pp_master.pd_sink);
-    }
 
 errout_with_devpair:
   nxsem_destroy(&devpair->pp_exclsem);

include/nuttx/fs/fs.h

@@ -1492,6 +1492,7 @@ int nx_unlink(FAR const char *pathname);
  ****************************************************************************/
 
 #if defined(CONFIG_PIPES) && CONFIG_DEV_PIPE_SIZE > 0
+int file_pipe(FAR struct file *filep[2], size_t bufsize, int flags);
 int nx_pipe(int fd[2], size_t bufsize, int flags);
 #endif