mirror of
https://github.com/eclipse-threadx/filex.git
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170 lines
7.7 KiB
C
170 lines
7.7 KiB
C
/**************************************************************************/
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/* */
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/* Copyright (c) Microsoft Corporation. All rights reserved. */
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/* */
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/* This software is licensed under the Microsoft Software License */
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/* Terms for Microsoft Azure RTOS. Full text of the license can be */
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/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
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/* and in the root directory of this software. */
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/* */
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/**************************************************************************/
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/**************************************************************************/
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/**************************************************************************/
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/** */
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/** FileX Component */
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/** */
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/** Media */
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/** */
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/**************************************************************************/
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/**************************************************************************/
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#define FX_SOURCE_CODE
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/* Include necessary system files. */
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#include "fx_api.h"
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#include "fx_media.h"
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#include "fx_utility.h"
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/**************************************************************************/
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/* */
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/* FUNCTION RELEASE */
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/* */
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/* _fx_media_check_lost_cluster_check PORTABLE C */
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/* 6.1 */
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/* AUTHOR */
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/* */
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/* William E. Lamie, Microsoft Corporation */
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/* */
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/* DESCRIPTION */
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/* */
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/* This function examines all clusters to see if there are any unused */
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/* clusters that are also unavailable. If specified, this routine will */
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/* also mark the cluster as available. */
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/* */
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/* INPUT */
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/* */
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/* media_ptr Pointer to a previously */
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/* opened media */
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/* logical_fat Pointer to the logical FAT */
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/* bit map */
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/* total_clusters Total number of clusters */
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/* error_correction_option Option for correcting lost */
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/* cluster errors */
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/* */
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/* OUTPUT */
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/* */
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/* error Error code */
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/* */
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/* CALLS */
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/* */
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/* _fx_utility_FAT_entry_read Read a FAT entry */
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/* _fx_utility_FAT_entry_write Write a FAT entry */
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/* */
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/* CALLED BY */
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/* */
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/* _fx_check_media Check media function */
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/* */
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/* RELEASE HISTORY */
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/* */
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/* DATE NAME DESCRIPTION */
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/* */
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/* 05-19-2020 William E. Lamie Initial Version 6.0 */
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/* 09-30-2020 William E. Lamie Modified comment(s), */
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/* resulting in version 6.1 */
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/* */
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/**************************************************************************/
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ULONG _fx_media_check_lost_cluster_check(FX_MEDIA *media_ptr, UCHAR *logical_fat, ULONG total_clusters, ULONG error_correction_option)
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{
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ULONG cluster, next_cluster = 0;
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ULONG fat_last;
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ULONG error;
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UINT status;
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/* Calculate the FAT reserved and last sector values. */
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if (media_ptr -> fx_media_32_bit_FAT)
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{
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fat_last = FX_LAST_CLUSTER_1_32;
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}
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else
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{
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fat_last = FX_LAST_CLUSTER_1;
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}
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/* Initialize the error. */
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error = 0;
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/* Loop through all the clusters to see if any clusters NOT in the logical sector FAT have
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a non zero value. */
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for (cluster = FX_FAT_ENTRY_START; cluster < total_clusters; cluster++)
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{
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/* Determine if this cluster is in the logical FAT. */
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if (logical_fat[cluster >> 3] & (1 << (cluster & 7)))
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{
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/* Yes, the cluster is in use by a file or sub-directory. Just continue the loop. */
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continue;
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}
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/* Otherwise, the cluster is not in use. */
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/* Read the contents of what should be a free cluster. */
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status = _fx_utility_FAT_entry_read(media_ptr, cluster, &next_cluster);
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/* Check for a good status. */
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if (status)
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{
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/* Set the error code. */
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error = error | FX_IO_ERROR;
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/* Return error code. */
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return(error);
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}
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/* Determine if the contents of the cluster is valid. */
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if (((next_cluster > (ULONG)FX_FREE_CLUSTER) && (next_cluster < media_ptr -> fx_media_fat_reserved)) ||
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(next_cluster >= fat_last))
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{
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/* Lost cluster is present. */
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/* Set the error code status. */
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error = FX_LOST_CLUSTER_ERROR;
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/* Determine if the lost cluster should be recovered. */
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if (error_correction_option & FX_LOST_CLUSTER_ERROR)
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{
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/* Make the cluster available again. */
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status = _fx_utility_FAT_entry_write(media_ptr, cluster, FX_FREE_CLUSTER);
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/* Check for a good status. */
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if (status)
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{
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/* Increment the available clusters. */
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media_ptr -> fx_media_available_clusters++;
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/* Set the error code. */
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error = error | FX_IO_ERROR;
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/* Return error code. */
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return(error);
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}
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}
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}
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}
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/* Return error code. */
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return(error);
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}
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