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fs/nxffs: truncate method is implementated in a separate file and should have been in a previous commit.

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Gregory Nutt 2018-01-04 11:01:23 -06:00
parent 39fe6a0dff
commit 42701f99fa
1 changed files with 138 additions and 0 deletions
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138
fs/nxffs/nxffs_truncate.c Normal file
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/****************************************************************************
* fs/nxffs/nxffs_truncate.c
*
* Copyright (C) 2018 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* References: Linux/Documentation/filesystems/romfs.txt
*
* 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 <fcntl.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/semaphore.h>
#include "nxffs.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxffs_truncate
*
* Description:
* Set the length of the open, regular file associated with the file
* structure 'filep' to 'length'.
*
****************************************************************************/
int nxffs_truncate(FAR struct file *filep, off_t length)
{
FAR struct nxffs_volume_s *volume;
FAR struct nxffs_wrfile_s *wrfile;
off_t oldsize;
int ret;
finfo("Write %d bytes to offset %d\n", buflen, filep->f_pos);
/* Sanity checks */
DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
/* Recover the open file state from the struct file instance */
wrfile = (FAR struct nxffs_wrfile_s *)filep->f_priv;
/* Recover the volume state from the open file */
volume = (FAR struct nxffs_volume_s *)filep->f_inode->i_private;
DEBUGASSERT(volume != NULL);
/* Get exclusive access to the volume. Note that the volume exclsem
* protects the open file list.
*/
ret = nxsem_wait(&volume->exclsem);
if (ret < 0)
{
ferr("ERROR: nxsem_wait failed: %d\n", ret);
goto errout;
}
/* Check if the file was opened with write access */
if ((wrfile->ofile.oflags & O_WROK) == 0)
{
ferr("ERROR: File not open for write access\n");
ret = -EACCES;
goto errout_with_semaphore;
}
/* Are we shrinking the file? Or extending it? */
oldsize = wrfile->ofile.entry.datlen;
if (oldsize == length)
{
ret = OK;
goto errout_with_semaphore;
}
else if (oldsize > length)
{
/* We are shrinking the file */
/* REVISIT: Logic to shrink the file has not yet been implemented */
ret = -ENOSYS;
}
else
{
/* We are zero-extending the file. This essential amount to a write-
* append operation with zero data.
*/
ret = nxffs_wrextend(volume, wrfile, length);
}
errout_with_semaphore:
nxsem_post(&volume->exclsem);
errout:
return ret;
}