193 lines
4.8 KiB
C
193 lines
4.8 KiB
C
/****************************************************************************
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* drivers/bch/bchlib_write.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 <sys/types.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <string.h>
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#include <errno.h>
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#include <assert.h>
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#include <debug.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/drivers/drivers.h>
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#include "bch.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: bchlib_write
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*
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* Description:
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* Write to the block device set-up by bchlib_setup as if it were a
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* character device.
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*
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****************************************************************************/
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ssize_t bchlib_write(FAR void *handle, FAR const char *buffer, off_t offset,
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size_t len)
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{
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FAR struct bchlib_s *bch = (FAR struct bchlib_s *)handle;
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size_t nsectors;
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size_t sector;
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uint16_t sectoffset;
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size_t nbytes;
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size_t byteswritten;
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int ret;
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/* Get rid of this special case right away */
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if (len < 1)
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{
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return 0;
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}
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/* Convert the file position into a sector number and offset. */
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sector = offset / bch->sectsize;
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sectoffset = offset - sector * bch->sectsize;
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if (sector >= bch->nsectors)
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{
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return -EFBIG;
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}
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/* Write the initial partial sector */
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byteswritten = 0;
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if (sectoffset > 0)
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{
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/* Read the full sector into the sector buffer */
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ret = bchlib_readsector(bch, sector);
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if (ret < 0)
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{
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return ret;
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}
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/* Copy the tail end of the sector from the user buffer */
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if (sectoffset + len > bch->sectsize)
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{
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nbytes = bch->sectsize - sectoffset;
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}
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else
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{
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nbytes = len;
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}
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memcpy(&bch->buffer[sectoffset], buffer, nbytes);
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bch->dirty = true;
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/* Adjust pointers and counts */
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sector++;
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if (sector >= bch->nsectors)
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{
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return nbytes;
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}
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byteswritten = nbytes;
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buffer += nbytes;
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len -= nbytes;
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}
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/* Then write all of the full sectors following the partial sector
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* directly from the user buffer.
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*/
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if (len >= bch->sectsize)
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{
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nsectors = len / bch->sectsize;
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if (sector + nsectors > bch->nsectors)
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{
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nsectors = bch->nsectors - sector;
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}
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/* Flush the dirty sector to keep the sector sequence */
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ret = bchlib_flushsector(bch, sector <= bch->sector &&
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bch->sector < (sector + nsectors));
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if (ret < 0)
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{
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ferr("ERROR: Flush failed: %d\n", ret);
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return ret;
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}
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/* Write the contiguous sectors */
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ret = bch->inode->u.i_bops->write(bch->inode, (FAR uint8_t *)buffer,
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sector, nsectors);
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if (ret < 0)
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{
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ferr("ERROR: Write failed: %d\n", ret);
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return ret;
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}
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/* Adjust pointers and counts */
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sector += nsectors;
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nbytes = nsectors * bch->sectsize;
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byteswritten += nbytes;
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if (sector >= bch->nsectors)
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{
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return byteswritten;
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}
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buffer += nbytes;
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len -= nbytes;
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}
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/* Then write any partial final sector */
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if (len > 0)
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{
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/* Read the sector into the sector buffer */
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ret = bchlib_readsector(bch, sector);
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if (ret < 0)
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{
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return ret;
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}
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/* Copy the head end of the sector from the user buffer */
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memcpy(bch->buffer, buffer, len);
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bch->dirty = true;
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/* Adjust counts */
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byteswritten += len;
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}
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return byteswritten;
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}
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