Filesystem: Add readv/writev handlers

The readv() and writev() support was implemented in terms of multiple
calls to the read and write handlers.  This imposes a problem on device
files which use an IO vector as single request entity.  For example a
low-level network device (e.g. BPF(4)) may use an IO vector to create
one frame from multiple protocol layers each with its own IO vector
entry.

3 files changed, 123 insertions, 1 deletions

diff --git a/cpukit/libfs/src/defaults/default_handlers.c b/cpukit/libfs/src/defaults/default_handlers.c
index 2a10a19125..ce262b66a3 100644
--- a/cpukit/libfs/src/defaults/default_handlers.c
+++ b/cpukit/libfs/src/defaults/default_handlers.c
@@ -32,5 +32,7 @@ const rtems_filesystem_file_handlers_r rtems_filesystem_handlers_default = {
   .ftruncate_h = rtems_filesystem_default_ftruncate,
   .fsync_h = rtems_filesystem_default_fsync_or_fdatasync,
   .fdatasync_h = rtems_filesystem_default_fsync_or_fdatasync,
-  .fcntl_h = rtems_filesystem_default_fcntl
+  .fcntl_h = rtems_filesystem_default_fcntl,
+  .readv_h = rtems_filesystem_default_readv,
+  .writev_h = rtems_filesystem_default_writev
 };
diff --git a/cpukit/libfs/src/defaults/default_readv.c b/cpukit/libfs/src/defaults/default_readv.c
new file mode 100644
index 0000000000..063ed5e678
--- /dev/null
+++ b/cpukit/libfs/src/defaults/default_readv.c
@@ -0,0 +1,60 @@
+/**
+ * @file
+ *
+ * @brief Default Read IO Vector Handler
+ *
+ * @ingroup LibIOFSHandler
+ */
+
+/*
+ * COPYRIGHT (c) 1989-2011.
+ * On-Line Applications Research Corporation (OAR).
+ *
+ * Copyright (c) 2013 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/libio_.h>
+
+ssize_t rtems_filesystem_default_readv(
+  rtems_libio_t      *iop,
+  const struct iovec *iov,
+  int                 iovcnt,
+  ssize_t             total
+)
+{
+  int v;
+
+  total = 0;
+
+  for ( v = 0 ; v < iovcnt ; ++v ) {
+    ssize_t bytes = ( *iop->pathinfo.handlers->read_h )(
+      iop,
+      iov[ v ].iov_base,
+      iov[ v ].iov_len
+    );
+
+    if ( bytes < 0 )
+      return -1;
+
+    total += bytes;
+
+    if ( bytes != iov[ v ].iov_len )
+      break;
+  }
+
+  return total;
+}
diff --git a/cpukit/libfs/src/defaults/default_writev.c b/cpukit/libfs/src/defaults/default_writev.c
new file mode 100644
index 0000000000..e62e084e72
--- /dev/null
+++ b/cpukit/libfs/src/defaults/default_writev.c
@@ -0,0 +1,60 @@
+/**
+ * @file
+ *
+ * @brief Default Read IO Vector Handler
+ *
+ * @ingroup LibIOFSHandler
+ */
+
+/*
+ * COPYRIGHT (c) 1989-2011.
+ * On-Line Applications Research Corporation (OAR).
+ *
+ * Copyright (c) 2013 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/libio_.h>
+
+ssize_t rtems_filesystem_default_writev(
+  rtems_libio_t      *iop,
+  const struct iovec *iov,
+  int                 iovcnt,
+  ssize_t             total
+)
+{
+  int v;
+
+  total = 0;
+
+  for ( v = 0 ; v < iovcnt ; ++v ) {
+    ssize_t bytes = ( *iop->pathinfo.handlers->write_h )(
+      iop,
+      iov[ v ].iov_base,
+      iov[ v ].iov_len
+    );
+
+    if ( bytes < 0 )
+      return -1;
+
+    total += bytes;
+
+    if ( bytes != iov[ v ].iov_len )
+      break;
+  }
+
+  return total;
+}