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/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** FileX Component */
/** */
/** Fault Tolerant */
/** */
/**************************************************************************/
/**************************************************************************/
#define FX_SOURCE_CODE
#include "fx_api.h"
#include "fx_utility.h"
#include "fx_fault_tolerant.h"
#ifdef FX_ENABLE_FAULT_TOLERANT
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _fx_fault_tolerant_read_directory_sector PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function handles directory sector read requests. During file or*/
/* directory operations with Fault Tolerant protection, intermediate */
/* operations are written to the fault tolerant log files. Therefore, */
/* sector read should search for fault tolerant log before the request */
/* can be passed to normal directory entry read routine. */
/* */
/* INPUT */
/* */
/* media_ptr Media control block pointer */
/* logical_sector Logical sector number */
/* buffer_ptr Pointer of receiving buffer */
/* sectors Number of sectors to read */
/* */
/* OUTPUT */
/* */
/* return status */
/* */
/* CALLS */
/* */
/* _fx_utility_16_unsigned_read Read a USHORT from memory */
/* _fx_utility_32_unsigned_read Read a ULONG from memory */
/* memcpy Memory Copy */
/* */
/* CALLED BY */
/* */
/* _fx_utility_logical_sector_read */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 William E. Lamie Initial Version 6.0 */
/* 09-30-2020 William E. Lamie Modified comment(s), verified */
/* memcpy usage, */
/* resulting in version 6.1 */
/* */
/**************************************************************************/
UINT _fx_fault_tolerant_read_directory_sector(FX_MEDIA *media_ptr, ULONG64 logical_sector,
VOID *buffer_ptr, ULONG64 sectors)
{
ULONG logs_remaining;
ULONG copy_offset;
ULONG copy_size;
UCHAR *current_ptr;
UCHAR *current_buffer_ptr;
ULONG size;
USHORT type;
ULONG log_len;
ULONG64 log_sector;
FX_FAULT_TOLERANT_DIR_LOG *dir_log;
/* Get fault tolerant data. */
logs_remaining = media_ptr -> fx_media_fault_tolerant_total_logs;
/* Any redo logs? */
if (logs_remaining == 0)
{
/* No. Just return. */
return(FX_SUCCESS);
}
/* Get size of all logs. */
size = media_ptr -> fx_media_fault_tolerant_file_size - FX_FAULT_TOLERANT_LOG_CONTENT_OFFSET;
/* Get the first log pointer. */
current_ptr = media_ptr -> fx_media_fault_tolerant_memory_buffer +
FX_FAULT_TOLERANT_LOG_CONTENT_OFFSET +
FX_FAULT_TOLERANT_LOG_CONTENT_HEADER_SIZE;
/* Loop throught all FAT logs. */
while (logs_remaining)
{
/* Check log type. */
type = (USHORT)_fx_utility_16_unsigned_read(current_ptr);
/* Get log length. */
log_len = _fx_utility_16_unsigned_read(current_ptr + 2);
/* Validate the size value. */
if (log_len > size)
{
/* Log file is corrupted. Nothing can be done. Return.*/
return(FX_FILE_CORRUPT);
}
size -= log_len;
/* Check log type. */
if (type == FX_FAULT_TOLERANT_DIR_LOG_TYPE)
{
/* Get the log pointer. */
dir_log = (FX_FAULT_TOLERANT_DIR_LOG *)current_ptr;
/* Get the sector of log. */
log_sector = _fx_utility_64_unsigned_read((UCHAR *)&dir_log -> fx_fault_tolerant_dir_log_sector);
/* Is this log sector in the range of sectors to read? */
if ((log_sector >= logical_sector) && (log_sector < logical_sector + sectors))
{
/* Yes. Update the content in this sector. */
current_buffer_ptr = ((UCHAR *)buffer_ptr) + (log_sector - logical_sector) *
media_ptr -> fx_media_bytes_per_sector;
/* Set copy information. */
copy_offset = _fx_utility_32_unsigned_read((UCHAR *)&dir_log -> fx_fault_tolerant_dir_log_offset);
copy_size = log_len - FX_FAULT_TOLERANT_DIR_LOG_ENTRY_SIZE;
if ((copy_offset + copy_size) > media_ptr -> fx_media_bytes_per_sector)
{
return(FX_FILE_CORRUPT);
}
/* Copy data into destination sector. */
memcpy(current_buffer_ptr + copy_offset, /* Use case of memcpy is verified. */
current_ptr + FX_FAULT_TOLERANT_DIR_LOG_ENTRY_SIZE, copy_size);
}
}
/* Decrease the logs_remaining counter. */
logs_remaining--;
/* Move to start position of next log entry. */
current_ptr += log_len;
}
/* Return success. */
return(FX_SUCCESS);
}
#endif /* FX_ENABLE_FAULT_TOLERANT */
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