fs/vfs: Change the return value of internal function fs_getfilep(). It no longer sets the errno variable but, rather, returns errors in the same manner as other internal OS functions.

fs/aio/aio_fsync.c

@@ -99,10 +99,8 @@ static void aio_fsync_worker(FAR void *arg)
   ret = file_fsync(aioc->u.aioc_filep);
   if (ret < 0)
     {
-      int errcode = get_errno();
+      ferr("ERROR: file_fsync failed: %d\n", ret);
-      ferr("ERROR: fsync failed: %d\n", errcode);
+      aiocbp->aio_result = ret;
-      DEBUGASSERT(errcode > 0);
-      aiocbp->aio_result = -errcode;
     }
   else
     {

fs/aio/aioc_contain.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/aio/aioc_contain.c
  *
- *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2014, 2017 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -86,6 +86,7 @@ FAR struct aio_container_s *aio_contain(FAR struct aiocb *aiocbp)
 #ifdef CONFIG_PRIORITY_INHERITANCE
   struct sched_param param;
 #endif
+  int ret;
 
 #if defined(AIO_HAVE_FILEP) && defined(AIO_HAVE_PSOCK)
   if (aiocbp->aio_fildes < CONFIG_NFILE_DESCRIPTORS)
@@ -94,13 +95,13 @@ FAR struct aio_container_s *aio_contain(FAR struct aiocb *aiocbp)
     {
       /* Get the file structure corresponding to the file descriptor. */
 
-      u.filep = fs_getfilep(aiocbp->aio_fildes);
+      ret = fs_getfilep(aiocbp->aio_fildes, &u.filep);
-      if (!u.filep)
+      if (ret < 0)
         {
-          /* The errno value has already been set */
+          goto errout;
-
-          return NULL;
         }
+
+      DEBUGASSERT(u.filep != NULL);
     }
 #endif
 #if defined(AIO_HAVE_FILEP) && defined(AIO_HAVE_PSOCK)
@@ -111,12 +112,14 @@ FAR struct aio_container_s *aio_contain(FAR struct aiocb *aiocbp)
       /* Get the socket structure corresponding to the socket descriptor */
 
       u.psock = sockfd_socket(aiocbp->aio_fildes);
-      if (!u.psock)
+      if (u.psock == NULL)
         {
-          /* Does not set the errno.  EBADF is the most likely explanation. */
+          /* Does not return error information.  EBADF is the most likely
+           * explanation.
+           */
 
-          set_errno(EBADF);
+          ret = -EBADF;
-          return NULL;
+          goto errout;
         }
     }
 #endif
@@ -146,6 +149,10 @@ FAR struct aio_container_s *aio_contain(FAR struct aiocb *aiocbp)
   dq_addlast(&aioc->aioc_link, &g_aio_pending);
   aio_unlock();
   return aioc;
+
+errout:
+  set_errno(-ret);
+  return NULL;
 }
 
 /****************************************************************************

fs/vfs/fs_dupfd.c

@@ -55,10 +55,6 @@
 
 #define DUP_ISOPEN(filep) (filep->f_inode != NULL)
 
-/****************************************************************************
- * Private Functions
- ****************************************************************************/
-
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -128,24 +124,27 @@ int fs_dupfd(int fd, int minfd)
 
   /* Get the file structure corresponding to the file descriptor. */
 
-  filep = fs_getfilep(fd);
+  ret = fs_getfilep(fd, &filep);
-  if (!filep)
+  if (ret < 0)
     {
-      /* The errno value has already been set */
+      goto errout;
-
-      return ERROR;
     }
 
+  DEBUGASSERT(filep != NULL);
+
   /* Let file_dup() do the real work */
 
   ret = file_dup(filep, minfd);
   if (ret < 0)
     {
-      set_errno(-ret);
+      goto errout;
-      return ERROR;
     }
 
   return OK;
+
+errout:
+  set_errno(-ret);
+  return ERROR;
 }
 
 #endif /* CONFIG_NFILE_DESCRIPTORS > 0 */

fs/vfs/fs_dupfd2.c

@@ -1,7 +1,8 @@
 /****************************************************************************
  * fs/vfs/fs_dupfd2.c
  *
- *   Copyright (C) 2007-2009, 2011-2014 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2014, 2017 Gregory Nutt. All rights
+ *     reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -84,27 +85,30 @@ int dup2(int fd1, int fd2)
 #endif
 {
   FAR struct file *filep1;
-  FAR struct file *filep2;
+  FAR struct file *filep2 = NULL;
   int ret;
 
   /* Get the file structures corresponding to the file descriptors. */
 
-  filep1 = fs_getfilep(fd1);
+  ret = fs_getfilep(fd1, &filep1);
-  filep2 = fs_getfilep(fd2);
+  if (ret >= 0)
-
-  if (!filep1 || !filep2)
     {
-      /* The errno value has already been set */
+      ret = fs_getfilep(fd2, &filep2);
-
-      return ERROR;
     }
 
+  if (ret < 0)
+    {
+      goto errout;
+    }
+
+  DEBUGASSERT(filep1 != NULL && filep2 != NULL);
+
   /* Verify that fd1 is a valid, open file descriptor */
 
   if (!DUP_ISOPEN(filep1))
     {
-      set_errno(EBADF);
+      ret = -EBADF;
-      return ERROR;
+      goto errout;
     }
 
   /* Handle a special case */
@@ -119,11 +123,14 @@ int dup2(int fd1, int fd2)
   ret = file_dup2(filep1, filep2);
   if (ret < 0)
     {
-      set_errno(-ret);
+      goto errout;
-      return ERROR;
     }
 
   return OK;
+
+errout:
+  set_errno(-ret);
+  return ERROR;
 }
 
 #endif /* CONFIG_NFILE_DESCRIPTORS > 0 */

fs/vfs/fs_fcntl.c

@@ -254,21 +254,17 @@ int fcntl(int fd, int cmd, ...)
     {
       /* Get the file structure corresponding to the file descriptor. */
 
-      filep = fs_getfilep(fd);
+      ret = fs_getfilep(fd, &filep);
-      if (!filep)
+      if (ret >= 0)
         {
-          /* The errno value has already been set */
+          DEBUGASSERT(filep != NULL);
 
-          va_end(ap);
+          /* Let file_vfcntl() do the real work.  The errno is not set on
-          leave_cancellation_point();
+           * failures.
-          return ERROR;
+           */
+
+          ret = file_vfcntl(filep, cmd, ap);
         }
-
-      /* Let file_vfcntl() do the real work.  The errno is not set on
-       * failures.
-       */
-
-      ret = file_vfcntl(filep, cmd, ap);
     }
   else
 #endif

fs/vfs/fs_fdopen.c

@@ -67,17 +67,16 @@ static inline int fs_checkfd(FAR struct tcb_s *tcb, int fd, int oflags)
 {
   FAR struct file *filep;
   FAR struct inode *inode;
+  int ret;
 
   DEBUGASSERT(tcb && tcb->group);
 
   /* Get the file structure corresponding to the file descriptor. */
 
-  filep = fs_getfilep(fd);
+  ret = fs_getfilep(fd, &filep);
-  if (!filep)
+  if (ret < 0)
     {
-      /* The errno value has already been set */
+      return ret;
-
-      return ERROR;
     }
 
   /* Get the inode associated with the file descriptor.  This should

fs/vfs/fs_fstat.c

@@ -84,8 +84,8 @@ int fstat(int fd, FAR struct stat *buf)
     {
       /* No networking... it is a bad descriptor in any event */
 
-      set_errno(EBADF);
+      ret = -EBADF;
-      return ERROR;
+      goto errout;
     }
 
   /* The descriptor is in a valid range to file descriptor... do the
@@ -93,14 +93,14 @@ int fstat(int fd, FAR struct stat *buf)
    * fs_getfilep() will set the errno variable.
    */
 
-  filep = fs_getfilep(fd);
+  ret = fs_getfilep(fd, &filep);
-  if (filep == NULL)
+  if (ret < 0)
     {
-      /* The errno value has already been set */
+      goto errout;
-
-      return ERROR;
     }
 
+  DEBUGASSERT(filep != NULL);
+
   /* Get the inode from the file structure */
 
   inode = filep->f_inode;
@@ -135,13 +135,14 @@ int fstat(int fd, FAR struct stat *buf)
 
   /* Check if the fstat operation was successful */
 
-  if (ret < 0)
+  if (ret >= 0)
     {
-      set_errno(-ret);
+      /* Successfully fstat'ed the file */
-      return ERROR;
+
+      return OK;
     }
 
-  /* Successfully fstat'ed the file */
+errout:
-
+  set_errno(-ret);
-  return OK;
+  return ERROR;
 }

fs/vfs/fs_fstatfs.c

@@ -81,8 +81,8 @@ int fstatfs(int fd, FAR struct statfs *buf)
     {
       /* It is a bad, out-of-range descriptor */
 
-      set_errno(EBADF);
+      ret = -EBADF;
-      return ERROR;
+      goto errout;
     }
 
   /* The descriptor is in a valid range to file descriptor... do the
@@ -90,14 +90,14 @@ int fstatfs(int fd, FAR struct statfs *buf)
    * fs_getfilep() will set the errno variable.
    */
 
-  filep = fs_getfilep(fd);
+  ret = fs_getfilep(fd, &filep);
-  if (filep == NULL)
+  if (ret < 0)
     {
-      /* The errno value has already been set */
+      goto errout;
-
-      return ERROR;
     }
 
+  DEBUGASSERT(filep != NULL);
+
   /* Get the inode from the file structure */
 
   inode = filep->f_inode;
@@ -144,13 +144,14 @@ int fstatfs(int fd, FAR struct statfs *buf)
 
   /* Check if the fstat operation was successful */
 
-  if (ret < 0)
+  if (ret >= 0)
     {
-      set_errno(-ret);
+      /* Successfully statfs'ed the file */
-      return ERROR;
+
+      return OK;
     }
 
-  /* Successfully statfs'ed the file */
+errout:
-
+  set_errno(-ret);
-  return OK;
+  return ERROR;
 }

fs/vfs/fs_fsync.c

@@ -1,7 +1,8 @@
 /****************************************************************************
  * fs/vfs/fs_fsync.c
  *
- *   Copyright (C) 2007-2009, 2013-2014, 2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2013-2014, 2016-2017 Gregory Nutt. All rights
+ *     reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -61,22 +62,20 @@
  *
  * Description:
  *   Equivalent to the standard fsync() function except that is accepts a
- *   struct file instance instead of a file descriptor.  Currently used
+ *   struct file instance instead of a file descriptor and it does not set
- *   only by aio_fsync();
+ *   the errno variable.
  *
  ****************************************************************************/
 
 int file_fsync(FAR struct file *filep)
 {
   struct inode *inode;
-  int ret;
 
   /* Was this file opened for write access? */
 
   if ((filep->f_oflags & O_WROK) == 0)
     {
-      ret = EBADF;
+      return -EBADF;
-      goto errout;
     }
 
   /* Is this inode a registered mountpoint? Does it support the
@@ -88,23 +87,12 @@ int file_fsync(FAR struct file *filep)
   if (!inode || !INODE_IS_MOUNTPT(inode) ||
       !inode->u.i_mops || !inode->u.i_mops->sync)
     {
-      ret = EINVAL;
+      return -EINVAL;
-      goto errout;
     }
 
   /* Yes, then tell the mountpoint to sync this file */
 
-  ret = inode->u.i_mops->sync(filep);
+  return inode->u.i_mops->sync(filep);
-  if (ret >= 0)
-    {
-      return OK;
-    }
-
-  ret = -ret;
-
-errout:
-  set_errno(ret);
-  return ERROR;
 }
 
 /****************************************************************************
@@ -126,20 +114,29 @@ int fsync(int fd)
 
   /* Get the file structure corresponding to the file descriptor. */
 
-  filep = fs_getfilep(fd);
+  ret = fs_getfilep(fd, &filep);
-  if (!filep)
+  if (ret < 0)
     {
-      /* The errno value has already been set */
+      goto errout;
-
-      leave_cancellation_point();
-      return ERROR;
     }
 
+  DEBUGASSERT(filep != NULL);
+
   /* Perform the fsync operation */
 
   ret = file_fsync(filep);
+  if (ret < 0)
+    {
+      goto errout;
+    }
+
   leave_cancellation_point();
   return ret;
+
+errout:
+  leave_cancellation_point();
+  set_errno(-ret);
+  return ERROR;
 }
 
 #endif /* !CONFIG_DISABLE_MOUNTPOINT */

fs/vfs/fs_getfilep.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/vfs/fs_getfilep.c
  *
- *   Copyright (C) 2014, 2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2014, 2016-2017 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -48,10 +48,6 @@
 
 #include "inode/inode.h"
 
-/****************************************************************************
- * Private Functions
- ****************************************************************************/
-
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -64,25 +60,26 @@
  *   file.  NOTE that this function will currently fail if it is provided
  *   with a socket descriptor.
  *
- * Parameters:
+ * Input Parameters:
- *   fd - The file descriptor
+ *   fd    - The file descriptor
+ *   filep - The location to return the struct file instance
  *
- * Return:
+ * Returned Value:
- *   A point to the corresponding struct file instance is returned on
+ *   Zero (OK) is returned on success; a negated errno value is returned on
- *   success.  On failure,  NULL is returned and the errno value is
+ *   any failure.
- *   set appropriately (EBADF).
  *
  ****************************************************************************/
 
-FAR struct file *fs_getfilep(int fd)
+int fs_getfilep(int fd, FAR struct file **filep)
 {
   FAR struct filelist *list;
-  int errcode;
+
+  DEBUGASSERT(filep != NULL);
+  *filep = (FAR struct file *)NULL;
 
   if ((unsigned int)fd >= CONFIG_NFILE_DESCRIPTORS)
     {
-      errcode = EBADF;
+      return -EBADF;
-      goto errout;
     }
 
   /* The descriptor is in a valid range to file descriptor... Get the
@@ -100,15 +97,11 @@ FAR struct file *fs_getfilep(int fd)
 
   if (list == NULL)
     {
-      errcode = EAGAIN;
+      return -EAGAIN;
-      goto errout;
     }
 
   /* And return the file pointer from the list */
 
-  return &list->fl_files[fd];
+  *filep = &list->fl_files[fd];
-
+  return OK;
-errout:
-  set_errno(errcode);
-  return NULL;
 }

fs/vfs/fs_ioctl.c

@@ -1,7 +1,8 @@
 /****************************************************************************
  * fs/vfs/fs_ioctl.c
  *
- *   Copyright (C) 2007-2010, 2012-2014, 2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2010, 2012-2014, 2016-2017 Gregory Nutt. All rights
+ *     reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -68,7 +69,9 @@
  *   arg      The argument of the ioctl cmd
  *
  * Return:
- *   See ioctl() below.
+ *   Returns a non-negative number on success;  A negated errno value is
+ *   returned on any failure (see comments ioctl() for a list of appropriate
+ *   errno values).
  *
  ****************************************************************************/
 
@@ -76,8 +79,6 @@
 int file_ioctl(FAR struct file *filep, int req, unsigned long arg)
 {
   FAR struct inode *inode;
-  int errcode;
-  int ret;
 
   DEBUGASSERT(filep != NULL);
 
@@ -86,32 +87,19 @@ int file_ioctl(FAR struct file *filep, int req, unsigned long arg)
   inode = filep->f_inode;
   if (!inode)
     {
-      errcode = EBADF;
+      return -EBADF;
-      goto errout;
     }
 
   /* Does the driver support the ioctl method? */
 
   if (inode->u.i_ops == NULL || inode->u.i_ops->ioctl == NULL)
     {
-      errcode = ENOTTY;
+      return -ENOTTY;
-      goto errout;
     }
 
   /* Yes on both accounts.  Let the driver perform the ioctl command */
 
-  ret = (int)inode->u.i_ops->ioctl(filep, req, arg);
+  return (int)inode->u.i_ops->ioctl(filep, req, arg);
-  if (ret < 0)
-    {
-      errcode = -ret;
-      goto errout;
-    }
-
-  return ret;
-
-errout:
-  set_errno(errcode);
-  return ERROR;
 }
 #endif /* CONFIG_NFILE_DESCRIPTORS > 0 */
 
@@ -153,6 +141,7 @@ int ioctl(int fd, int req, unsigned long arg)
   int errcode;
 #if CONFIG_NFILE_DESCRIPTORS > 0
   FAR struct file *filep;
+  int ret;
 
   /* Did we get a valid file descriptor? */
 
@@ -164,7 +153,7 @@ int ioctl(int fd, int req, unsigned long arg)
 #if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
       if ((unsigned int)fd < (CONFIG_NFILE_DESCRIPTORS+CONFIG_NSOCKET_DESCRIPTORS))
         {
-          int ret = netdev_ioctl(fd, req, arg);
+          ret = netdev_ioctl(fd, req, arg);
           if (ret < 0)
             {
               errcode = -ret;
@@ -184,22 +173,27 @@ int ioctl(int fd, int req, unsigned long arg)
 #if CONFIG_NFILE_DESCRIPTORS > 0
   /* Get the file structure corresponding to the file descriptor. */
 
-  filep = fs_getfilep(fd);
+  ret = fs_getfilep(fd, &filep);
-  if (!filep)
+  if (ret < 0)
     {
-      /* Apparently, the fd does not correspond to any open file.  In the
+      errcode = -ret;
-       * case of errors, the errno value has already been set by
+      goto errout;
-       * fs_getfilep().
-       */
-
-      return ERROR;
     }
 
+  DEBUGASSERT(filep != NULL);
+
   /* Perform the file ioctl.  If file_ioctl() fails, it will set the errno
    * value appropriately.
    */
 
-  return file_ioctl(filep, req, arg);
+  ret = file_ioctl(filep, req, arg);
+  if (ret < 0)
+    {
+      errcode = -ret;
+      goto errout;
+    }
+
+  return ret;
 #else
   errcode = ENOTTY;
 #endif

fs/vfs/fs_lseek.c

@@ -162,27 +162,34 @@ off_t lseek(int fd, off_t offset, int whence)
 {
   FAR struct file *filep;
   off_t newpos;
+  int errcode;
+  int ret;
 
   /* Get the file structure corresponding to the file descriptor. */
 
-  filep = fs_getfilep(fd);
+  ret = fs_getfilep(fd, &filep);
-  if (!filep)
+  if (ret < 0)
     {
-      /* The errno value has already been set */
+      errcode = -ret;
-
+      goto errout;
-      return (off_t)ERROR;
     }
 
+  DEBUGASSERT(filep != NULL);
+
   /* Then let file_seek do the real work */
 
-   newpos = file_seek(filep, offset, whence);
+  newpos = file_seek(filep, offset, whence);
-   if (newpos < 0)
+  if (newpos < 0)
-     {
+    {
-       set_errno((int)-newpos);
+      errcode = (int)-newpos;
-       return (off_t)ERROR;
+      goto errout;
-     }
+    }
 
    return newpos;
+
+errout:
+  set_errno(errcode);
+  return (off_t)ERROR;
 }
 
 #endif

fs/vfs/fs_open.c

@@ -1,7 +1,8 @@
 /****************************************************************************
  * fs/vfs/fs_open.c
  *
- *   Copyright (C) 2007-2009, 2011-2012, 2016-2017 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2012, 2016-2017 Gregory Nutt. All rights
+ *     reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -216,12 +217,11 @@ int open(const char *path, int oflags, ...)
 
   /* Get the file structure corresponding to the file descriptor. */
 
-  filep = fs_getfilep(fd);
+  ret = fs_getfilep(fd, &filep);
-  if (!filep)
+  if (ret < 0)
     {
-      /* The errno value has already been set */
+      ret = -ret;
-
+      goto errout_with_inode;
-      goto errout;
     }
 
   /* Perform the driver open operation.  NOTE that the open method may be

fs/vfs/fs_poll.c

@@ -321,7 +321,8 @@ int file_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup)
  *   setup - true: Setup up the poll; false: Teardown the poll
  *
  * Returned Value:
- *  0: Success; Negated errno on failure
+ *  Zero (OK) is returned on success; a negated errno value is returned on
+ *  any failure.
  *
  ****************************************************************************/
 
@@ -329,19 +330,18 @@ int file_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup)
 int fdesc_poll(int fd, FAR struct pollfd *fds, bool setup)
 {
   FAR struct file *filep;
+  int ret;
 
   /* Get the file pointer corresponding to this file descriptor */
 
-  filep = fs_getfilep(fd);
+  ret = fs_getfilep(fd, &filep);
-  if (!filep)
+  if (ret < 0)
     {
-      /* The errno value has already been set */
+      return ret;
-
-      int errorcode = get_errno();
-      DEBUGASSERT(errorcode > 0);
-      return -errorcode;
     }
 
+  DEBUGASSERT(filep != NULL);
+
   /* Let file_poll() do the rest */
 
   return file_poll(filep, fds, setup);

fs/vfs/fs_pread.c

@@ -41,6 +41,7 @@
 
 #include <sys/types.h>
 #include <unistd.h>
+#include <assert.h>
 #include <errno.h>
 
 #include <nuttx/cancelpt.h>
@@ -146,25 +147,27 @@ ssize_t pread(int fd, FAR void *buf, size_t nbytes, off_t offset)
 
   /* Get the file structure corresponding to the file descriptor. */
 
-  filep = fs_getfilep(fd);
+  ret = (ssize_t)fs_getfilep(fd, &filep);
-  if (!filep)
+  if (ret < 0)
     {
-      /* The errno value has already been set */
+      goto errout;
-
-      ret = (ssize_t)ERROR;
     }
-  else
-    {
-      /* Let file_pread do the real work */
 
-      ret = file_pread(filep, buf, nbytes, offset);
+  DEBUGASSERT(filep != NULL);
-      if (ret < 0)
+
-        {
+  /* Let file_pread do the real work */
-          set_errno((int)-ret);
+
-          ret = (ssize_t)ERROR;
+  ret = file_pread(filep, buf, nbytes, offset);
-        }
+  if (ret < 0)
+    {
+      goto errout;
     }
 
   leave_cancellation_point();
   return ret;
+
+errout:
+  set_errno((int)-ret);
+  leave_cancellation_point();
+  return (ssize_t)ERROR;
 }

fs/vfs/fs_pwrite.c

@@ -144,25 +144,25 @@ ssize_t pwrite(int fd, FAR const void *buf, size_t nbytes, off_t offset)
 
   /* Get the file structure corresponding to the file descriptor. */
 
-  filep = fs_getfilep(fd);
+  ret = (ssize_t)fs_getfilep(fd, &filep);
-  if (!filep)
+  if (ret < 0)
     {
-      /* The errno value has already been set */
+      goto errout;
-
-      ret = (ssize_t)ERROR;
-    }
-  else
-    {
-      /* Let file_pread do the real work */
-
-      ret = file_pwrite(filep, buf, nbytes, offset);
-      if (ret < 0)
-        {
-          set_errno((int)-ret);
-          ret = (ssize_t)ERROR;
-        }
     }
 
-  (void)enter_cancellation_point();
+  /* Let file_pwrite do the real work */
+
+  ret = file_pwrite(filep, buf, nbytes, offset);
+  if (ret < 0)
+    {
+      goto errout;
+    }
+
+  leave_cancellation_point();
   return ret;
+
+errout:
+  set_errno((int)-ret);
+  leave_cancellation_point();
+  return (ssize_t)ERROR;
 }

fs/vfs/fs_read.c

@@ -1,7 +1,8 @@
 /****************************************************************************
  * fs/vfs/fs_read.c
  *
- *   Copyright (C) 2007-2009, 2012-2014, 2016-2017 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2012-2014, 2016-2017 Gregory Nutt. All rights
+ *     reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -148,8 +149,8 @@ ssize_t read(int fd, FAR void *buf, size_t nbytes)
 #else
       /* No networking... it is a bad descriptor in any event */
 
-      set_errno(EBADF);
+      ret = -EBADF;
-      ret = ERROR;
+      goto errout;
 #endif
     }
 
@@ -163,27 +164,27 @@ ssize_t read(int fd, FAR void *buf, size_t nbytes)
        * fs_getfilep() will set the errno variable.
        */
 
-      filep = fs_getfilep(fd);
+      ret = (ssize_t)fs_getfilep(fd, &filep);
-      if (filep == NULL)
+      if (ret < 0)
         {
-          /* The errno value has already been set */
+          goto errout;
-
-          ret = ERROR;
         }
-      else
-        {
-          /* Then let file_read do all of the work. */
 
-          ret = file_read(filep, buf, nbytes);
+      /* Then let file_read do all of the work. */
-          if (ret < 0)
+
-            {
+      ret = file_read(filep, buf, nbytes);
-              set_errno((int)-ret);
+      if (ret < 0)
-              ret = ERROR;
+        {
-            }
+          goto errout;
         }
     }
 #endif
 
   leave_cancellation_point();
   return ret;
+
+errout:
+  set_errno((int)-ret);
+  leave_cancellation_point();
+  return (ssize_t)ERROR;
 }

fs/vfs/fs_sendfile.c

@@ -1,7 +1,8 @@
 /****************************************************************************
  * fs/vfs/fs_sendfile.c
  *
- *   Copyright (C) 2007, 2009, 2011, 2013, 2017 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2009, 2011, 2013, 2017 Gregory Nutt. All rights
+ *     reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -111,19 +112,21 @@ ssize_t sendfile(int outfd, int infd, off_t *offset, size_t count)
       (unsigned int)infd < CONFIG_NFILE_DESCRIPTORS)
     {
       FAR struct file *filep;
+      int ret;
 
       /* This appears to be a file-to-socket transfer.  Get the file
        * structure.
        */
 
-      filep = fs_getfilep(infd);
+      ret = fs_getfilep(infd, &filep);
-      if (!filep)
+      if (ret < 0)
         {
-          /* The errno value has already been set */
+          set_errno(-ret);
-
           return ERROR;
         }
 
+      DEBUGASSERT(filep != NULL);
+
       /* Then let net_sendfile do the work. */
 
       return net_sendfile(outfd, filep, offset, count);

fs/vfs/fs_write.c

@@ -1,7 +1,8 @@
 /****************************************************************************
  * fs/vfs/fs_write.c
  *
- *   Copyright (C) 2007-2009, 2012-2014, 2016-2017 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2012-2014, 2016-2017 Gregory Nutt. All rights
+ *     reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -155,8 +156,7 @@ ssize_t write(int fd, FAR const void *buf, size_t nbytes)
 
   if (buf == NULL)
     {
-      set_errno(EINVAL);
+      ret = -EINVAL;
-      ret = ERROR;
       goto errout;
     }
 
@@ -173,8 +173,8 @@ ssize_t write(int fd, FAR const void *buf, size_t nbytes)
 
       ret = send(fd, buf, nbytes, 0);
 #else
-      set_errno(EBADF);
+      ret = -EBADF;
-      ret = ERROR;
+      goto errout;
 #endif
     }
 
@@ -186,30 +186,29 @@ ssize_t write(int fd, FAR const void *buf, size_t nbytes)
        * failure.
        */
 
-      filep = fs_getfilep(fd);
+      ret = (ssize_t)fs_getfilep(fd, &filep);
-      if (filep == NULL)
+      if (ret < 0)
         {
-          /* The errno value has already been set */
+          goto errout;
-
-          ret = ERROR;
         }
-      else
-        {
-          /* Perform the write operation using the file descriptor as an
-           * index.  Note that file_write() will set the errno on failure.
-           */
 
-          ret = file_write(filep, buf, nbytes);
+      /* Perform the write operation using the file descriptor as an
-          if (ret < 0)
+       * index.  Note that file_write() will set the errno on failure.
-            {
+       */
-              set_errno((int)-ret);
+
-              ret = ERROR;
+      ret = file_write(filep, buf, nbytes);
-            }
+      if (ret < 0)
+        {
+          goto errout;
         }
     }
 #endif
 
-errout:
   leave_cancellation_point();
   return ret;
+
+errout:
+  set_errno(-ret);
+  leave_cancellation_point();
+  return ERROR;
 }

include/nuttx/fs/fs.h

@@ -1,7 +1,8 @@
 /****************************************************************************
  * include/nuttx/fs/fs.h
  *
- *   Copyright (C) 2007-2009, 2011-2013, 2015-2017 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2013, 2015-2017 Gregory Nutt. All rights
+ *     reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -61,6 +62,36 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+/* Most internal OS interfaces are not available in the user space in
+ * PROTECTED and KERNEL builds.  In that context, the corresponding
+ * application interfaces must be used.  The differences between the two
+ * sets of interfaces are:  The internal OS interfaces (1) do not cause
+ * cancellation points and (2) they do not modify the errno variable.
+ *
+ * This is only important when compiling libraries (libc or libnx) that are
+ * used both by the OS (libkc.a and libknx.a) or by the applications
+ * (libuc.a and libunx.a).  The that case, the correct interface must be
+ * used for the build context.
+ *
+ * The interfaces open(), close(), creat(), read(), pread(), write(),
+ * pwrite(), poll(), select(), fcntl(), and aio_suspend() are all
+ * cancellation points.
+ *
+ * REVISIT:  These cancellation points are an issue and may cause
+ * violations:  It use of these internally will cause the calling function
+ * to become a cancellation points!
+ */
+
+#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
+#  define _NX_WRITE(f,b,s)     nx_write(s,b,s)
+#  define _NX_ERRNO(r)         (-(r))
+#  define _NX_ERRVAL(r)        (r)
+#else
+#  define _NX_WRITE(f,b,s)     rite(s,b,s)
+#  define _NX_ERRNO(r)         errno
+#  define _NX_ERRVAL(r)        (-errno)
+#endif
+
 /* Stream flags for the fs_flags field of in struct file_struct */
 
 #define __FS_FLAG_EOF   (1 << 0) /* EOF detected by a read operation */
@@ -739,13 +770,13 @@ int file_close_detached(FAR struct file *filep);
  * Description:
  *   Return the inode of the block driver specified by 'pathname'
  *
- * Inputs:
+ * Input Parameters:
  *   pathname - the full path to the block driver to be opened
  *   mountflags - if MS_RDONLY is not set, then driver must support write
  *     operations (see include/sys/mount.h)
  *   ppinode - address of the location to return the inode reference
  *
- * Return:
+ * Returned Value:
  *   Returns zero on success or a negated errno on failure:
  *
  *   EINVAL  - pathname or pinode is NULL
@@ -767,10 +798,10 @@ int open_blockdriver(FAR const char *pathname, int mountflags,
  * Description:
  *   Call the close method and release the inode
  *
- * Inputs:
+ * Input Parameters:
  *   inode - reference to the inode of a block driver opened by open_blockdriver
  *
- * Return:
+ * Returned Value:
  *   Returns zero on success or a negated errno on failure:
  *
  *   EINVAL  - inode is NULL
@@ -788,12 +819,12 @@ int close_blockdriver(FAR struct inode *inode);
  * Description:
  *   Perform device specific operations.
  *
- * Parameters:
+ * Input Parameters:
  *   fd       File/socket descriptor of device
  *   req      The ioctl command
  *   arg      The argument of the ioctl cmd
  *
- * Return:
+ * Returned Value:
  *   >=0 on success (positive non-zero values are cmd-specific)
  *   -1 on failure with errno set properly:
  *
@@ -862,18 +893,18 @@ ssize_t lib_sendfile(int outfd, int infd, off_t *offset, size_t count);
  *   file.  NOTE that this function will currently fail if it is provided
  *   with a socket descriptor.
  *
- * Parameters:
+ * Input Parameters:
- *   fd - The file descriptor
+ *   fd    - The file descriptor
+ *   filep - The location to return the struct file instance
  *
- * Return:
+ * Returned Value:
- *   A point to the corresponding struct file instance is returned on
+ *   Zero (OK) is returned on success; a negated errno value is returned on
- *   success.  On failure,  NULL is returned and the errno value is
+ *   any failure.
- *   set appropriately (EBADF).
  *
  ****************************************************************************/
 
 #if CONFIG_NFILE_DESCRIPTORS > 0
-FAR struct file *fs_getfilep(int fd);
+int fs_getfilep(int fd, FAR struct file **filep);
 #endif
 
 /****************************************************************************
@@ -953,8 +984,8 @@ off_t file_seek(FAR struct file *filep, off_t offset, int whence);
  *
  * Description:
  *   Equivalent to the standard fsync() function except that is accepts a
- *   struct file instance instead of a file descriptor.  Currently used
+ *   struct file instance instead of a file descriptor and it does not set
- *   only by aio_fsync();
+ *   the errno variable.
  *
  ****************************************************************************/
 
@@ -974,7 +1005,9 @@ int file_fsync(FAR struct file *filep);
  *   arg      The argument of the ioctl cmd
  *
  * Return:
- *   See ioctl() below.
+ *   Returns a non-negative number on success;  A negated errno value is
+ *   returned on any failure (see comments ioctl() for a list of appropriate
+ *   errno values).
  *
  ****************************************************************************/