Major structure of file system functions to better support asynchronous I/O. Respository should not be trusted until I have a chance to verify everything

18 files changed, 484 insertions, 260 deletions

diff --git a/nuttx/fs/vfs/Make.defs b/nuttx/fs/vfs/Make.defs
index 583aaf070..1780eabd6 100644
--- a/nuttx/fs/vfs/Make.defs
+++ b/nuttx/fs/vfs/Make.defs
@@ -69,10 +69,10 @@ else
 
 # Common file/socket descriptor support
 
-CSRCS += fs_close.c fs_dup.c fs_dup2.c fs_fcntl.c fs_filedup.c fs_filedup2.c
-CSRCS += fs_fsync.c fs_ioctl.c fs_lseek.c fs_mkdir.c fs_open.c fs_poll.c
-CSRCS += fs_read.c fs_rename.c fs_rmdir.c fs_stat.c fs_statfs.c fs_select.c
-CSRCS += fs_unlink.c fs_write.c
+CSRCS += fs_close.c fs_dup.c fs_dup2.c fs_fcntl.c fs_dupfd.c fs_dupfd2.c
+CSRCS += fs_fsync.c fs_getfilep.c fs_ioctl.c fs_lseek.c fs_mkdir.c fs_open.c
+CSRCS += fs_poll.c fs_read.c fs_rename.c fs_rmdir.c fs_stat.c fs_statfs.c
+CSRCS += fs_select.c fs_unlink.c fs_write.c
 
 # Support for positional file access
 
diff --git a/nuttx/fs/vfs/fs_dup.c b/nuttx/fs/vfs/fs_dup.c
index 2c4dd785d..5981dc8cd 100644
--- a/nuttx/fs/vfs/fs_dup.c
+++ b/nuttx/fs/vfs/fs_dup.c
@@ -68,7 +68,7 @@
 
 int dup(int fd)
 {
- int ret = OK;
+  int ret = OK;
 
   /* Check the range of the descriptor to see if we got a file or a socket
    * descriptor. */
@@ -79,19 +79,19 @@ int dup(int fd)
       /* Its a valid file descriptor.. dup the file descriptor using any
        * other file descriptor*/
 
-      ret = file_dup(fd, 0);
+      ret = fs_dupfd(fd, 0);
     }
   else
 #endif
     {
-      /* Not a vailid file descriptor.  Did we get a valid socket descriptor? */
+      /* Not a valid file descriptor.  Did we get a valid socket descriptor? */
 
 #if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
       if ((unsigned int)fd < (CONFIG_NFILE_DESCRIPTORS+CONFIG_NSOCKET_DESCRIPTORS))
         {
           /* Yes.. dup the socket descriptor */
 
-          ret = net_dup(fd, CONFIG_NFILE_DESCRIPTORS);
+          ret = net_dupsd(fd, CONFIG_NFILE_DESCRIPTORS);
         }
       else
 #endif
diff --git a/nuttx/fs/vfs/fs_dup2.c b/nuttx/fs/vfs/fs_dup2.c
index ff6eabdb4..3164e0b2f 100644
--- a/nuttx/fs/vfs/fs_dup2.c
+++ b/nuttx/fs/vfs/fs_dup2.c
@@ -87,7 +87,7 @@ int dup2(int fd1, int fd2)
         {
           /* Yes.. dup the socket descriptor */
 
-          return net_dup2(fd1, fd2);
+          return net_dupsd2(fd1, fd2);
         }
       else
         {
@@ -101,7 +101,7 @@ int dup2(int fd1, int fd2)
     {
       /* Its a valid file descriptor.. dup the file descriptor */
 
-      return file_dup2(fd1, fd2);
+      return fs_dupfd2(fd1, fd2);
     }
 }
 
diff --git a/nuttx/fs/vfs/fs_filedup.c b/nuttx/fs/vfs/fs_dupfd.c
index f474a096e..5d319641d 100644
--- a/nuttx/fs/vfs/fs_filedup.c
+++ b/nuttx/fs/vfs/fs_dupfd.c
@@ -1,7 +1,7 @@
 /****************************************************************************
- * fs/vfs/fs_filedup.c
+ * fs/vfs/fs_dupfd.c
  *
- *   Copyright (C) 2007-2009, 2011-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -53,43 +53,33 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-#define DUP_ISOPEN(fd, list) \
-  ((unsigned int)fd < CONFIG_NFILE_DESCRIPTORS && \
-   list->fl_files[fd].f_inode != NULL)
+#define DUP_ISOPEN(filep) (filep->f_inode != NULL)
 
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Global Functions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Name: file_dup OR dup
+ * Name: file_dup
  *
  * Description:
- *   Clone a file descriptor 'fd' to an arbitray descriptor number (any value
- *   greater than or equal to 'minfd'). If socket descriptors are
- *   implemented, then this is called by dup() for the case of file
- *   descriptors.  If socket descriptors are not implemented, then this
- *   function IS dup().
+ *   Equivalent to the non-standard fs_dupfd() function except that it
+ *   accepts a struct file instance instead of a file descriptor.  Currently
+ *   used only by file_vfcntl();
  *
  ****************************************************************************/
 
-int file_dup(int fd, int minfd)
+int file_dup(FAR struct file *filep, int minfd)
 {
-  FAR struct filelist *list;
   int fd2;
 
-  /* Get the thread-specific file list */
-
-  list = sched_getfiles();
-  DEBUGASSERT(list);
-
   /* Verify that fd is a valid, open file descriptor */
 
-  if (!DUP_ISOPEN(fd, list))
+  if (!DUP_ISOPEN(filep))
     {
       set_errno(EBADF);
       return ERROR;
@@ -97,23 +87,51 @@ int file_dup(int fd, int minfd)
 
   /* Increment the reference count on the contained inode */
 
-  inode_addref(list->fl_files[fd].f_inode);
+  inode_addref(filep->f_inode);
 
   /* Then allocate a new file descriptor for the inode */
 
-  fd2 = files_allocate(list->fl_files[fd].f_inode,
-                       list->fl_files[fd].f_oflags,
-                       list->fl_files[fd].f_pos,
-                       minfd);
+  fd2 = files_allocate(filep->f_inode, filep->f_oflags, filep->f_pos, minfd);
   if (fd2 < 0)
     {
       set_errno(EMFILE);
-      inode_release(list->fl_files[fd].f_inode);
+      inode_release(filep->f_inode);
       return ERROR;
     }
 
   return fd2;
 }
 
+/****************************************************************************
+ * Name: fs_dupfd OR dup
+ *
+ * Description:
+ *   Clone a file descriptor 'fd' to an arbitray descriptor number (any value
+ *   greater than or equal to 'minfd'). If socket descriptors are
+ *   implemented, then this is called by dup() for the case of file
+ *   descriptors.  If socket descriptors are not implemented, then this
+ *   function IS dup().
+ *
+ ****************************************************************************/
+
+int fs_dupfd(int fd, int minfd)
+{
+  FAR struct file *filep;
+
+  /* Get the file structure corresponding to the file descriptor. */
+
+  filep = fs_getfilep(fd);
+  if (!filep)
+    {
+      /* The errno value has already been set */
+
+      return ERROR;
+    }
+
+  /* Let file_dup() do the real work */
+
+  return file_dup(filep, minfd);
+}
+
 #endif /* CONFIG_NFILE_DESCRIPTORS > 0 */
 
diff --git a/nuttx/fs/vfs/fs_filedup2.c b/nuttx/fs/vfs/fs_dupfd2.c
index 73b29c32e..6043430bd 100644
--- a/nuttx/fs/vfs/fs_filedup2.c
+++ b/nuttx/fs/vfs/fs_dupfd2.c
@@ -1,7 +1,7 @@
 /****************************************************************************
- * fs/vfs/fs_filedup2.c
+ * fs/vfs/fs_dupfd2.c
  *
- *   Copyright (C) 2007-2009, 2011-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -51,9 +51,7 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-#define DUP_ISOPEN(fd, list) \
-  ((unsigned int)fd < CONFIG_NFILE_DESCRIPTORS && \
-   list->fl_files[fd].f_inode != NULL)
+#define DUP_ISOPEN(filep) (filep->f_inode != NULL)
 
 /****************************************************************************
  * Private Functions
@@ -64,7 +62,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: file_dup2 OR dup2
+ * Name: fs_dupfd2 OR dup2
  *
  * Description:
  *   Clone a file descriptor to a specific descriptor number. If socket
@@ -75,25 +73,29 @@
  ****************************************************************************/
 
 #if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
-int file_dup2(int fd1, int fd2)
+int fs_dupfd2(int fd1, int fd2)
 #else
 int dup2(int fd1, int fd2)
 #endif
 {
-  FAR struct filelist *list;
+  FAR struct file *filep1;
+  FAR struct file *filep2;
 
-  /* Get the thread-specific file list */
+  /* Get the file structures corresponding to the file descriptors. */
 
-  list = sched_getfiles();
-  if (!list)
+  filep1 = fs_getfilep(fd1);
+  filep2 = fs_getfilep(fd2);
+
+  if (!filep1 || !filep2)
     {
-      set_errno(EMFILE);
+      /* The errno value has already been set */
+
       return ERROR;
     }
 
-  /* Verify that fd is a valid, open file descriptor */
+  /* Verify that fd1 is a valid, open file descriptor */
 
-  if (!DUP_ISOPEN(fd1, list))
+  if (!DUP_ISOPEN(filep1))
     {
       set_errno(EBADF);
       return ERROR;
@@ -106,15 +108,9 @@ int dup2(int fd1, int fd2)
       return fd1;
     }
 
-  /* Verify fd2 */
-
-  if ((unsigned int)fd2 >= CONFIG_NFILE_DESCRIPTORS)
-    {
-      set_errno(EBADF);
-      return ERROR;
-    }
+  /* Perform the dup2 operation */
 
-  return files_dup(&list->fl_files[fd1], &list->fl_files[fd2]);
+  return file_dup2(filep1, filep2);
 }
 
 #endif /* CONFIG_NFILE_DESCRIPTORS > 0 */
diff --git a/nuttx/fs/vfs/fs_fcntl.c b/nuttx/fs/vfs/fs_fcntl.c
index 6e4ebefb1..f4d67ae45 100644
--- a/nuttx/fs/vfs/fs_fcntl.c
+++ b/nuttx/fs/vfs/fs_fcntl.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/vfs/fs_fcntl.c
  *
- *   Copyright (C) 2009, 2012-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2009, 2012-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -59,25 +59,27 @@
  ****************************************************************************/
 
 /****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
  * Name: file_vfcntl
+ *
+ * Description:
+ *   Similar to the standard vfcntl function except that is accepts a struct
+ *   struct file instance instead of a file descriptor.  Currently used
+ *   only by aio_fcntl();
+ *
  ****************************************************************************/
 
 #if CONFIG_NFILE_DESCRIPTORS > 0
-static inline int file_vfcntl(int fd, int cmd, va_list ap)
+int file_vfcntl(FAR struct file *filep, int cmd, va_list ap)
 {
-  FAR struct filelist *list;
-  FAR struct file *filep;
   int err = 0;
   int ret = OK;
 
-  /* Get the thread-specific file list */
-
-  list = sched_getfiles();
-  DEBUGASSERT(list);
-
   /* Was this file opened ? */
 
-  filep = &list->fl_files[fd];
   if (!filep->f_inode)
     {
       err = EBADF;
@@ -98,7 +100,7 @@ static inline int file_vfcntl(int fd, int cmd, va_list ap)
          */
 
         {
-          ret = file_dup(fd, va_arg(ap, int));
+          ret = file_dup(filep, va_arg(ap, int));
         }
         break;
 
@@ -217,15 +219,12 @@ errout:
 #endif /* CONFIG_NFILE_DESCRIPTORS > 0 */
 
 /****************************************************************************
- * Global Functions
- ****************************************************************************/
-
-/****************************************************************************
  * Name: fcntl
  ****************************************************************************/
 
 int fcntl(int fd, int cmd, ...)
 {
+  FAR struct file *filep;
   va_list ap;
   int ret;
 
@@ -238,9 +237,19 @@ int fcntl(int fd, int cmd, ...)
 #if CONFIG_NFILE_DESCRIPTORS > 0
   if ((unsigned int)fd < CONFIG_NFILE_DESCRIPTORS)
     {
-       /* Yes.. defer file operations to file_vfcntl() */
+      /* Get the file structure corresponding to the file descriptor. */
+
+      filep = fs_getfilep(fd);
+      if (!filep)
+        {
+          /* The errno value has already been set */
 
-       ret = file_vfcntl(fd, cmd, ap);
+          return ERROR;
+        }
+
+      /* Let file_vfcntl() do the real work */
+
+      ret = file_vfcntl(filep, cmd, ap);
     }
   else
 #endif
@@ -266,4 +275,3 @@ int fcntl(int fd, int cmd, ...)
   va_end(ap);
   return ret;
 }
-
diff --git a/nuttx/fs/vfs/fs_fdopen.c b/nuttx/fs/vfs/fs_fdopen.c
index ece6f0fe9..882337da1 100644
--- a/nuttx/fs/vfs/fs_fdopen.c
+++ b/nuttx/fs/vfs/fs_fdopen.c
@@ -65,22 +65,28 @@
 #if CONFIG_NFILE_DESCRIPTORS > 0
 static inline int fs_checkfd(FAR struct tcb_s *tcb, int fd, int oflags)
 {
-  FAR struct filelist *flist;
-  FAR struct inode    *inode;
+  FAR struct file *filep;
+  FAR struct inode *inode;
 
   DEBUGASSERT(tcb && tcb->group);
 
-  /* Get the file list from the task group */
+  /* Get the file structure corresponding to the file descriptor. */
 
-  flist = &tcb->group->tg_filelist;
+  filep = fs_getfilep(fd);
+  if (!filep)
+    {
+      /* The errno value has already been set */
+
+      return ERROR;
+    }
 
   /* Get the inode associated with the file descriptor.  This should
    * normally be the case if fd >= 0.  But not in the case where the
-   * called attempts to explictly stdin with fdopen(0) but stdin has
+   * called attempts to explicitly stdin with fdopen(0) but stdin has
    * been closed.
    */
 
-  inode = flist->fl_files[fd].f_inode;
+  inode = filep->f_inode;
   if (!inode)
     {
       /* No inode -- descriptor does not correspond to an open file */
diff --git a/nuttx/fs/vfs/fs_fsync.c b/nuttx/fs/vfs/fs_fsync.c
index d608cda5f..24e184142 100644
--- a/nuttx/fs/vfs/fs_fsync.c
+++ b/nuttx/fs/vfs/fs_fsync.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/vfs/fs_fsync.c
  *
- *   Copyright (C) 2007-2009, 2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2013-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -70,36 +70,22 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: fsync
+ * Name: file_fsync
  *
  * Description:
- *   This func simply binds inode sync methods to the sync system call.
+ *   Equivalent to the standard fsync() function except that is accepts a
+ *   struct file instance instead of a file descriptor.  Currently used
+ *   only by aio_fsync();
  *
  ****************************************************************************/
 
-int fsync(int fd)
+int file_fsync(FAR struct file *filep)
 {
-  FAR struct filelist *list;
-  FAR struct file     *filep;
-  struct inode        *inode;
-  int                  ret;
-
-  /* Get the thread-specific file list */
-
-  list = sched_getfiles();
-  DEBUGASSERT(list);
-
-  /* Did we get a valid file descriptor? */
-
-  if ((unsigned int)fd >= CONFIG_NFILE_DESCRIPTORS)
-    {
-      ret = EBADF;
-      goto errout;
-    }
+  struct inode *inode;
+  int ret;
 
   /* Was this file opened for write access? */
 
-  filep = &list->fl_files[fd];
   if ((filep->f_oflags & O_WROK) == 0)
     {
       ret = EBADF;
@@ -134,3 +120,29 @@ errout:
   return ERROR;
 }
 
+/****************************************************************************
+ * Name: fsync
+ *
+ * Description:
+ *   This func simply binds inode sync methods to the sync system call.
+ *
+ ****************************************************************************/
+
+int fsync(int fd)
+{
+  FAR struct file *filep;
+
+  /* Get the file structure corresponding to the file descriptor. */
+
+  filep = fs_getfilep(fd);
+  if (!filep)
+    {
+      /* The errno value has already been set */
+
+      return ERROR;
+    }
+
+  /* Perform the fsync operation */
+
+  return file_fsync(filep);
+}
diff --git a/nuttx/fs/vfs/fs_getfilep.c b/nuttx/fs/vfs/fs_getfilep.c
new file mode 100644
index 000000000..165d00434
--- /dev/null
+++ b/nuttx/fs/vfs/fs_getfilep.c
@@ -0,0 +1,112 @@
+/****************************************************************************
+ * fs/vfs/fs_getfilep.c
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <errno.h>
+
+#include "inode/inode.h"
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: fs_getfilep
+ *
+ * Description:
+ *   Given a file descriptor, return the corresponding instance of struct
+ *   file.  NOTE that this function will currently fail if it is provided
+ *   with a socket descriptor.
+ *
+ * Parameters:
+ *   fd - The file descriptor
+ *
+ * Return:
+ *   A point to the corresponding struct file instance is returned on
+ *   success.  On failure,  NULL is returned and the errno value is
+ *   set appropriately (EBADF).
+ *
+ ****************************************************************************/
+
+FAR struct file *fs_getfilep(int fd)
+{
+  FAR struct filelist *list;
+  int errcode;
+
+  if ((unsigned int)fd >= CONFIG_NFILE_DESCRIPTORS)
+    {
+      errcode = EBADF;
+      goto errout;
+    }
+
+  /* The descriptor is in a valid range to file descriptor... Get the
+   * thread-specific file list.
+   */
+
+  list = sched_getfiles();
+
+  /* The file list can be NULL under one obscure cornercase:  When memory
+   * management debug output is enabled.  Then there may be attempts to
+   * write to stdout from malloc before the group data has been allocated.
+   */
+
+  if (!list)
+    {
+      errcode = EAGAIN;
+      goto errout;
+    }
+
+  /* And return the file pointer from the list */
+
+  return &list->fl_files[fd];
+
+errout:
+  set_errno(errcode);
+  return NULL;
+}
diff --git a/nuttx/fs/vfs/fs_ioctl.c b/nuttx/fs/vfs/fs_ioctl.c
index b0a7ad786..c0165cf7b 100644
--- a/nuttx/fs/vfs/fs_ioctl.c
+++ b/nuttx/fs/vfs/fs_ioctl.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/vfs/fs_ioctl.c
  *
- *   Copyright (C) 2007-2010, 2012-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2010, 2012-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -89,7 +89,6 @@ int ioctl(int fd, int req, unsigned long arg)
 {
   int err;
 #if CONFIG_NFILE_DESCRIPTORS > 0
-  FAR struct filelist *list;
   FAR struct file     *filep;
   FAR struct inode    *inode;
   int                  ret = OK;
@@ -115,16 +114,19 @@ int ioctl(int fd, int req, unsigned long arg)
     }
 
 #if CONFIG_NFILE_DESCRIPTORS > 0
-  /* Get the thread-specific file list */
+  /* Get the file structure corresponding to the file descriptor. */
 
-  list = sched_getfiles();
-  DEBUGASSERT(list);
+  filep = fs_getfilep(fd);
+  if (!filep)
+    {
+      /* The errno value has already been set */
+
+      return ERROR;
+    }
 
   /* Is a driver registered? Does it support the ioctl method? */
 
-  filep = &list->fl_files[fd];
   inode = filep->f_inode;
-
   if (inode && inode->u.i_ops && inode->u.i_ops->ioctl)
     {
       /* Yes, then let it perform the ioctl */
diff --git a/nuttx/fs/vfs/fs_lseek.c b/nuttx/fs/vfs/fs_lseek.c
index a4a45b5fd..7136d2ce1 100644
--- a/nuttx/fs/vfs/fs_lseek.c
+++ b/nuttx/fs/vfs/fs_lseek.c
@@ -50,7 +50,7 @@
 #if CONFIG_NFILE_DESCRIPTORS > 0
 
 /****************************************************************************
- * Global Functions
+ * Public Functions
  ****************************************************************************/
 
 /****************************************************************************
@@ -71,9 +71,6 @@
  *
  ****************************************************************************/
 
-#ifndef CONFIG_NET_SENDFILE
-static inline
-#endif
 off_t file_seek(FAR struct file *filep, off_t offset, int whence)
 {
   FAR struct inode *inode;
@@ -172,26 +169,21 @@ errout:
 
 off_t lseek(int fd, off_t offset, int whence)
 {
-  FAR struct filelist *list;
+  FAR struct file *filep;
 
-  /* Did we get a valid file descriptor? */
+  /* Get the file structure corresponding to the file descriptor. */
 
-  if ((unsigned int)fd >= CONFIG_NFILE_DESCRIPTORS)
+  filep = fs_getfilep(fd);
+  if (!filep)
     {
-      set_errno(EBADF);
+      /* The errno value has already been set */
+
       return (off_t)ERROR;
     }
-  else
-    {
-      /* Get the thread-specific file list */
-
-      list = sched_getfiles();
-      DEBUGASSERT(list);
 
-      /* Then let file_seek do the real work */
+  /* Then let file_seek do the real work */
 
-      return file_seek(&list->fl_files[fd], offset, whence);
-    }
+   return file_seek(filep, offset, whence);
 }
 
 #endif
diff --git a/nuttx/fs/vfs/fs_open.c b/nuttx/fs/vfs/fs_open.c
index 4c0596e7f..fd6562ac3 100644
--- a/nuttx/fs/vfs/fs_open.c
+++ b/nuttx/fs/vfs/fs_open.c
@@ -91,19 +91,14 @@ int inode_checkflags(FAR struct inode *inode, int oflags)
 
 int open(const char *path, int oflags, ...)
 {
-  FAR struct filelist *list;
-  FAR struct inode    *inode;
-  FAR const char      *relpath = NULL;
+  FAR struct file *filep;
+  FAR struct inode *inode;
+  FAR const char *relpath = NULL;
 #if defined(CONFIG_FILE_MODE) || !defined(CONFIG_DISABLE_MOUNTPOINT)
-  mode_t               mode = 0666;
+  mode_t mode = 0666;
 #endif
-  int                  ret;
-  int                  fd;
-
-  /* Get the thread-specific file list */
-
-  list = sched_getfiles();
-  DEBUGASSERT(list);
+  int ret;
+  int fd;
 
 #ifdef CONFIG_FILE_MODE
 #  ifdef CONFIG_CPP_HAVE_WARNING
@@ -168,6 +163,16 @@ int open(const char *path, int oflags, ...)
       goto errout_with_inode;
     }
 
+  /* Get the file structure corresponding to the file descriptor. */
+
+  filep = fs_getfilep(fd);
+  if (!filep)
+    {
+      /* The errno value has already been set */
+
+      return ERROR;
+    }
+
   /* Perform the driver open operation.  NOTE that the open method may be
    * called many times.  The driver/mountpoint logic should handled this
    * because it may also be closed that many times.
@@ -179,13 +184,12 @@ int open(const char *path, int oflags, ...)
 #ifndef CONFIG_DISABLE_MOUNTPOINT
       if (INODE_IS_MOUNTPT(inode))
         {
-          ret = inode->u.i_mops->open((FAR struct file*)&list->fl_files[fd],
-                                      relpath, oflags, mode);
+          ret = inode->u.i_mops->open(filep, relpath, oflags, mode);
         }
       else
 #endif
         {
-          ret = inode->u.i_ops->open((FAR struct file*)&list->fl_files[fd]);
+          ret = inode->u.i_ops->open(filep);
         }
     }
 
diff --git a/nuttx/fs/vfs/fs_poll.c b/nuttx/fs/vfs/fs_poll.c
index 701508917..3bdc817ca 100644
--- a/nuttx/fs/vfs/fs_poll.c
+++ b/nuttx/fs/vfs/fs_poll.c
@@ -97,10 +97,9 @@ static void poll_semtake(FAR sem_t *sem)
 #if CONFIG_NFILE_DESCRIPTORS > 0
 static int poll_fdsetup(int fd, FAR struct pollfd *fds, bool setup)
 {
-  FAR struct filelist *list;
-  FAR struct file     *filep;
-  FAR struct inode    *inode;
-  int                  ret = -ENOSYS;
+  FAR struct file *filep;
+  FAR struct inode *inode;
+  int ret = -ENOSYS;
 
   /* Check for a valid file descriptor */
 
@@ -120,18 +119,21 @@ static int poll_fdsetup(int fd, FAR struct pollfd *fds, bool setup)
         }
     }
 
-  /* Get the thread-specific file list */
+  /* Get the file pointer corresponding to this file descriptor */
 
-  list = sched_getfiles();
-  DEBUGASSERT(list);
+  filep = fs_getfilep(fd);
+  if (!filep)
+    {
+      /* The errno value has already been set */
+
+      return ERROR;
+    }
 
   /* Is a driver registered? Does it support the poll method?
    * If not, return -ENOSYS
    */
 
-  filep = &list->fl_files[fd];
   inode = filep->f_inode;
-
   if (inode && inode->u.i_ops && inode->u.i_ops->poll)
     {
       /* Yes, then setup the poll */
diff --git a/nuttx/fs/vfs/fs_pread.c b/nuttx/fs/vfs/fs_pread.c
index 3e4943439..e80efe66a 100644
--- a/nuttx/fs/vfs/fs_pread.c
+++ b/nuttx/fs/vfs/fs_pread.c
@@ -43,6 +43,8 @@
 #include <unistd.h>
 #include <errno.h>
 
+#include <nuttx/fs/fs.h>
+
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -52,56 +54,38 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: pread
+ * Name: file_pread
  *
  * Description:
- *   The pread() function performs the same action as read(), except that it
- *   reads from a given position in the file without changing the file
- *   pointer. The first three arguments to pread() are the same as read()
- *   with the addition of a fourth argument offset for the desired position
- *   inside the file. An attempt to perform a pread() on a file that is
- *   incapable of seeking results in an error.
- *
- *   NOTE: This function could have been wholly implemented within libc but
- *   it is not.  Why?  Because if pread were implemented in libc, it would
- *   require four system calls.  If it is implemented within the kernel,
- *   only three.
- *
- * Parameters:
- *   file     File structure instance
- *   buf      User-provided to save the data
- *   nbytes   The maximum size of the user-provided buffer
- *   offset   The file offset
- *
- * Return:
- *   The positive non-zero number of bytes read on success, 0 on if an
- *   end-of-file condition, or -1 on failure with errno set appropriately.
- *   See read() return values
+ *   Equivalent to the standard pread function except that is accepts a
+ *   struct file instance instead of a file descriptor.  Currently used
+ *   only by aio_read();
  *
  ****************************************************************************/
 
-ssize_t pread(int fd, FAR void *buf, size_t nbytes, off_t offset)
+ssize_t file_pread(FAR struct file *filep, FAR void *buf, size_t nbytes,
+                   off_t offset)
 {
   off_t savepos;
   off_t pos;
   ssize_t ret;
   int errcode;
 
-  /* Perform the lseek to the current position.  This will not move the
+  /* Perform the seek to the current position.  This will not move the
    * file pointer, but will return its current setting
    */
 
-  savepos = lseek(fd, 0, SEEK_CUR);
+  savepos = file_seek(filep, 0, SEEK_CUR);
   if (savepos == (off_t)-1)
     {
-      /* lseek might fail if this if the media is not seekable */
+      /* file_seek might fail if this if the media is not seekable */
 
       return ERROR;
     }
 
   /* Then seek to the correct position in the file */
 
-  pos = lseek(fd, offset, SEEK_SET);
+  pos = file_seek(filep, offset, SEEK_SET);
   if (pos == (off_t)-1)
     {
       /* This might fail is the offset is beyond the end of file */
@@ -111,12 +95,12 @@ ssize_t pread(int fd, FAR void *buf, size_t nbytes, off_t offset)
 
   /* Then perform the read operation */
 
-  ret = read(fd, buf, nbytes);
+  ret = file_read(filep, buf, nbytes);
   errcode = get_errno();
 
   /* Restore the file position */
 
-  pos = lseek(fd, savepos, SEEK_SET);
+  pos = file_seek(filep, savepos, SEEK_SET);
   if (pos == (off_t)-1 && ret >= 0)
     {
       /* This really should not fail */
@@ -127,3 +111,51 @@ ssize_t pread(int fd, FAR void *buf, size_t nbytes, off_t offset)
   set_errno(errcode);
   return ret;
 }
+
+/****************************************************************************
+ * Name: pread
+ *
+ * Description:
+ *   The pread() function performs the same action as read(), except that it
+ *   reads from a given position in the file without changing the file
+ *   pointer. The first three arguments to pread() are the same as read()
+ *   with the addition of a fourth argument offset for the desired position
+ *   inside the file. An attempt to perform a pread() on a file that is
+ *   incapable of seeking results in an error.
+ *
+ *   NOTE: This function could have been wholly implemented within libc but
+ *   it is not.  Why?  Because if pread were implemented in libc, it would
+ *   require four system calls.  If it is implemented within the kernel,
+ *   only three.
+ *
+ * Parameters:
+ *   file     File structure instance
+ *   buf      User-provided to save the data
+ *   nbytes   The maximum size of the user-provided buffer
+ *   offset   The file offset
+ *
+ * Return:
+ *   The positive non-zero number of bytes read on success, 0 on if an
+ *   end-of-file condition, or -1 on failure with errno set appropriately.
+ *   See read() return values
+ *
+ ****************************************************************************/
+
+ssize_t pread(int fd, FAR void *buf, size_t nbytes, off_t offset)
+{
+  FAR struct file *filep;
+
+  /* Get the file structure corresponding to the file descriptor. */
+
+  filep = fs_getfilep(fd);
+  if (!filep)
+    {
+      /* The errno value has already been set */
+
+      return (ssize_t)ERROR;
+    }
+
+  /* Let file_pread do the real work */
+
+  return file_pread(filep, buf, nbytes, offset);
+}
diff --git a/nuttx/fs/vfs/fs_pwrite.c b/nuttx/fs/vfs/fs_pwrite.c
index e7c1cf700..43630c455 100644
--- a/nuttx/fs/vfs/fs_pwrite.c
+++ b/nuttx/fs/vfs/fs_pwrite.c
@@ -43,6 +43,8 @@
 #include <unistd.h>
 #include <errno.h>
 
+#include <nuttx/fs/fs.h>
+
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -52,54 +54,38 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: pwrite
+ * Name: file_pwrite
  *
  * Description:
- *   The pwrite() function performs the same action as write(), except that
- *   it writes into a given position without changing the file pointer. The
- *   first three arguments to pwrite() are the same as write() with the
- *   addition of a fourth argument offset for the desired position inside
- *   the file.
- *
- *   NOTE: This function could have been wholly implemented within libc but
- *   it is not.  Why?  Because if pwrite were implemented in libc, it would
- *   require four system calls.  If it is implemented within the kernel,
- *   only three.
- *
- * Parameters:
- *   fd       file descriptor (or socket descriptor) to write to
- *   buf      Data to write
- *   nbytes   Length of data to write
- *
- * Return:
- *   The positive non-zero number of bytes read on success, 0 on if an
- *   end-of-file condition, or -1 on failure with errno set appropriately.
- *   See write() return values
+ *   Equivalent to the standard pwrite function except that is accepts a
+ *   struct file instance instead of a file descriptor.  Currently used
+ *   only by aio_write();
  *
  ****************************************************************************/
 
-ssize_t pwrite(int fd, FAR const void *buf, size_t nbytes, off_t offset)
+ssize_t file_pwrite(FAR struct file *filep, FAR const void *buf,
+                    size_t nbytes, off_t offset)
 {
   off_t savepos;
   off_t pos;
   ssize_t ret;
   int errcode;
 
-  /* Perform the lseek to the current position.  This will not move the
+  /* Perform the seek to the current position.  This will not move the
    * file pointer, but will return its current setting
    */
 
-  savepos = lseek(fd, 0, SEEK_CUR);
+  savepos = file_seek(filep, 0, SEEK_CUR);
   if (savepos == (off_t)-1)
     {
-      /* lseek might fail if this if the media is not seekable */
+      /* file_seek might fail if this if the media is not seekable */
 
       return ERROR;
     }
 
   /* Then seek to the correct position in the file */
 
-  pos = lseek(fd, offset, SEEK_SET);
+  pos = file_seek(filep, offset, SEEK_SET);
   if (pos == (off_t)-1)
     {
       /* This might fail is the offset is beyond the end of file */
@@ -109,12 +95,12 @@ ssize_t pwrite(int fd, FAR const void *buf, size_t nbytes, off_t offset)
 
   /* Then perform the write operation */
 
-  ret = write(fd, buf, nbytes);
+  ret = file_write(filep, buf, nbytes);
   errcode = get_errno();
 
   /* Restore the file position */
 
-  pos = lseek(fd, savepos, SEEK_SET);
+  pos = file_seek(filep, savepos, SEEK_SET);
   if (pos == (off_t)-1 && ret >= 0)
     {
       /* This really should not fail */
@@ -125,3 +111,49 @@ ssize_t pwrite(int fd, FAR const void *buf, size_t nbytes, off_t offset)
   set_errno(errcode);
   return ret;
 }
+
+/****************************************************************************
+ * Name: pwrite
+ *
+ * Description:
+ *   The pwrite() function performs the same action as write(), except that
+ *   it writes into a given position without changing the file pointer. The
+ *   first three arguments to pwrite() are the same as write() with the
+ *   addition of a fourth argument offset for the desired position inside
+ *   the file.
+ *
+ *   NOTE: This function could have been wholly implemented within libc but
+ *   it is not.  Why?  Because if pwrite were implemented in libc, it would
+ *   require four system calls.  If it is implemented within the kernel,
+ *   only three.
+ *
+ * Parameters:
+ *   fd       file descriptor (or socket descriptor) to write to
+ *   buf      Data to write
+ *   nbytes   Length of data to write
+ *
+ * Return:
+ *   The positive non-zero number of bytes read on success, 0 on if an
+ *   end-of-file condition, or -1 on failure with errno set appropriately.
+ *   See write() return values
+ *
+ ****************************************************************************/
+
+ssize_t pwrite(int fd, FAR const void *buf, size_t nbytes, off_t offset)
+{
+  FAR struct file *filep;
+
+  /* Get the file structure corresponding to the file descriptor. */
+
+  filep = fs_getfilep(fd);
+  if (!filep)
+    {
+      /* The errno value has already been set */
+
+      return (ssize_t)ERROR;
+    }
+
+  /* Let file_pread do the real work */
+
+  return file_pwrite(filep, buf, nbytes, offset);
+}
diff --git a/nuttx/fs/vfs/fs_read.c b/nuttx/fs/vfs/fs_read.c
index d9b7ed23a..c5cdc701e 100644
--- a/nuttx/fs/vfs/fs_read.c
+++ b/nuttx/fs/vfs/fs_read.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/vfs/fs_read.c
  *
- *   Copyright (C) 2007-2009, 2012-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2012-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -73,10 +73,6 @@
  *
  ****************************************************************************/
 
-#if CONFIG_NFILE_DESCRIPTORS > 0
-#ifndef CONFIG_NET_SENDFILE
-static inline
-#endif
 ssize_t file_read(FAR struct file *filep, FAR void *buf, size_t nbytes)
 {
   FAR struct inode *inode;
@@ -120,7 +116,6 @@ ssize_t file_read(FAR struct file *filep, FAR void *buf, size_t nbytes)
 
   return ret;
 }
-#endif /* CONFIG_NFILE_DESCRIPTORS > 0 */
 
 /****************************************************************************
  * Name: read
@@ -141,10 +136,6 @@ ssize_t file_read(FAR struct file *filep, FAR void *buf, size_t nbytes)
 
 ssize_t read(int fd, FAR void *buf, size_t nbytes)
 {
-#if CONFIG_NFILE_DESCRIPTORS > 0
-  FAR struct filelist *list;
-#endif
-
   /* Did we get a valid file descriptor? */
 
 #if CONFIG_NFILE_DESCRIPTORS > 0
@@ -168,16 +159,23 @@ ssize_t read(int fd, FAR void *buf, size_t nbytes)
 #if CONFIG_NFILE_DESCRIPTORS > 0
   else
     {
-      /* Thee descriptor is in a valid range to file descriptor... do the
-       * read. Get the thread-specific file list.
+      FAR struct file *filep;
+
+      /* The descriptor is in a valid range to file descriptor... do the
+       * read.  First, get the file structure.
        */
 
-      list = sched_getfiles();
-      DEBUGASSERT(list);
+      filep = fs_getfilep(fd);
+      if (!filep)
+        {
+          /* The errno value has already been set */
+
+          return ERROR;
+        }
 
       /* Then let file_read do all of the work */
 
-      return file_read(&list->fl_files[fd], buf, nbytes);
+      return file_read(filep, buf, nbytes);
     }
 #endif
 }
diff --git a/nuttx/fs/vfs/fs_sendfile.c b/nuttx/fs/vfs/fs_sendfile.c
index e5d935696..05c3d976e 100644
--- a/nuttx/fs/vfs/fs_sendfile.c
+++ b/nuttx/fs/vfs/fs_sendfile.c
@@ -127,18 +127,23 @@ ssize_t sendfile(int outfd, int infd, off_t *offset, size_t count)
   if ((unsigned int)outfd >= CONFIG_NFILE_DESCRIPTORS &&
       (unsigned int)infd < CONFIG_NFILE_DESCRIPTORS)
     {
-      FAR struct filelist *list;
+      FAR struct file *filep;
 
-      /* This appears to be a file-to-socket transfer.  Get the thread-
-       * specific file list.
+      /* This appears to be a file-to-socket transfer.  Get the file
+       * structure.
        */
 
-      list = sched_getfiles();
-      DEBUGASSERT(list);
+      filep = fs_getfilep(fd);
+      if (!filep)
+        {
+          /* The errno value has already been set */
+
+          return ERROR;
+        }
 
       /* Then let net_sendfile do the work. */
 
-      return net_sendfile(outfd, &list->fl_files[infd], offset, count);
+      return net_sendfile(outfd, filep, offset, count);
     }
   else
 #endif
diff --git a/nuttx/fs/vfs/fs_write.c b/nuttx/fs/vfs/fs_write.c
index 1c0ab8ea1..830e56dcc 100644
--- a/nuttx/fs/vfs/fs_write.c
+++ b/nuttx/fs/vfs/fs_write.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/vfs/fs_write.c
  *
- *   Copyright (C) 2007-2009, 2012-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2012-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -55,33 +55,28 @@
  * Private Functions
  ****************************************************************************/
 
-#if CONFIG_NFILE_DESCRIPTORS > 0
-static inline ssize_t file_write(int fd, FAR const void *buf, size_t nbytes)
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: file_write
+ *
+ * Description:
+ *   Equivalent to the standard write() function except that is accepts a
+ *   struct file instance instead of a file descriptor.  Currently used
+ *   only by aio_write();
+ *
+ ****************************************************************************/
+
+ssize_t file_write(FAR struct file *filep, FAR const void *buf, size_t nbytes)
 {
-  FAR struct filelist *list;
-  FAR struct file *filep;
   FAR struct inode *inode;
   int ret;
   int err;
 
-  /* Get the thread-specific file list */
-
-  list = sched_getfiles();
-
-  /* The file list can be NULL under one obscure cornercase:  When memory
-   * management debug output is enabled.  Then there may be attempts to
-   * write to stdout from malloc before the group data has been allocated.
-   */
-
-  if (!list)
-    {
-      err = EAGAIN;
-      goto errout;
-    }
-
   /* Was this file opened for write access? */
 
-  filep = &list->fl_files[fd];
   if ((filep->f_oflags & O_WROK) == 0)
     {
       err = EBADF;
@@ -112,11 +107,6 @@ errout:
   set_errno(err);
   return ERROR;
 }
-#endif
-
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
 
 /***************************************************************************
  * Name: write
@@ -170,6 +160,10 @@ errout:
 
 ssize_t write(int fd, FAR const void *buf, size_t nbytes)
 {
+#if CONFIG_NFILE_DESCRIPTORS > 0
+  FAR struct file *filep;
+#endif
+
   /* Did we get a valid file descriptor? */
 
 #if CONFIG_NFILE_DESCRIPTORS > 0
@@ -186,10 +180,21 @@ ssize_t write(int fd, FAR const void *buf, size_t nbytes)
 #endif
     }
 
-  /* The descriptor is in the right range to be a file descriptor... write to the file */
-
 #if CONFIG_NFILE_DESCRIPTORS > 0
-  return file_write(fd, buf, nbytes);
+  /* The descriptor is in the right range to be a file descriptor... write
+   * to the file.
+   */
+
+  filep = fs_getfilep(fd);
+  if (!filep)
+    {
+      /* The errno value has already been set */
+
+      return ERROR;
+    }
+
+  /* Perform the write operation using the file descriptor as an index */
+
+  return file_write(filep, buf, nbytes);
 #endif
 }
-