125 lines
3.5 KiB
C
125 lines
3.5 KiB
C
/****************************************************************************
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* fs/nxffs/nxffs_truncate.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <fcntl.h>
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#include <assert.h>
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#include <errno.h>
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#include <debug.h>
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#include "nxffs.h"
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#ifdef __NO_TRUNCATE_SUPPORT__
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: nxffs_truncate
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*
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* Description:
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* Set the length of the open, regular file associated with the file
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* structure 'filep' to 'length'.
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*
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****************************************************************************/
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int nxffs_truncate(FAR struct file *filep, off_t length)
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{
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FAR struct nxffs_volume_s *volume;
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FAR struct nxffs_wrfile_s *wrfile;
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off_t oldsize;
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int ret;
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finfo("Write %d bytes to offset %d\n", buflen, filep->f_pos);
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/* Sanity checks */
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DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
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/* Recover the open file state from the struct file instance */
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wrfile = (FAR struct nxffs_wrfile_s *)filep->f_priv;
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/* Recover the volume state from the open file */
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volume = (FAR struct nxffs_volume_s *)filep->f_inode->i_private;
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DEBUGASSERT(volume != NULL);
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/* Get exclusive access to the volume. Note that the volume lock
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* protects the open file list.
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*/
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ret = nxmutex_lock(&volume->lock);
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if (ret < 0)
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{
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ferr("ERROR: nxsem_wait failed: %d\n", ret);
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goto errout;
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}
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/* Check if the file was opened with write access */
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if ((wrfile->ofile.oflags & O_WROK) == 0)
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{
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ferr("ERROR: File not open for write access\n");
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ret = -EACCES;
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goto errout_with_lock;
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}
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/* Are we shrinking the file? Or extending it? */
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oldsize = wrfile->ofile.entry.datlen;
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if (oldsize == length)
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{
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ret = OK;
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goto errout_with_lock;
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}
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else if (oldsize > length)
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{
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/* We are shrinking the file.
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*
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* REVISIT: Logic to shrink the file has not yet been implemented.
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*/
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ret = -ENOSYS;
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}
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else
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{
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/* We are zero-extending the file. This essential amount to a write-
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* append operation with zero data.
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*/
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ret = nxffs_wrextend(volume, wrfile, length);
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}
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errout_with_lock:
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nxmutex_unlock(&volume->lock);
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errout:
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return ret;
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}
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#endif /* __NO_TRUNCATE_SUPPORT__ */
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