123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141 |
- /****************************************************************************
- * 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"
- #ifdef __NO_TRUNCATE_SUPPORT__
- /****************************************************************************
- * 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;
- }
- #endif /* __NO_TRUNCATE_SUPPORT__ */
|