Files
filex/common/src/fx_fault_tolerant_recover.c
T

160 lines
8.5 KiB
C

/**************************************************************************/
/* */
/* 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_recover PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function is called after the FAT chain is been updated but */
/* the rest of the write operation fails. At this point, there is */
/* need to undo the FAT chain operation, which includes: */
/* (1) Remove newly allocated FAT entries; */
/* (2) Restore the origianl FAT chain removed during the FAT chain */
/* update; */
/* */
/* INPUT */
/* */
/* media_ptr Media control block pointer */
/* */
/* OUTPUT */
/* */
/* return status */
/* */
/* CALLS */
/* */
/* _fx_fault_tolerant_cleanup_FAT_chain Cleanup FAT chain */
/* _fx_utility_32_unsigned_read Read a ULONG from memory */
/* _fx_utility_FAT_entry_write Write a FAT entry */
/* _fx_utility_FAT_flush Flush written FAT entries */
/* */
/* CALLED BY */
/* */
/* _fx_directory_attributes_set */
/* _fx_directory_create */
/* _fx_directory_delete */
/* _fx_directory_rename */
/* _fx_file_allocate */
/* _fx_file_attributes_set */
/* _fx_file_best_effort_allocate */
/* _fx_file_create */
/* _fx_file_delete */
/* _fx_file_rename */
/* _fx_file_truncate */
/* _fx_file_truncate_release */
/* _fx_file_write */
/* _fx_unicode_directory_create */
/* _fx_unicode_file_create */
/* _fx_fault_tolerant_enable */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 William E. Lamie Initial Version 6.0 */
/* 09-30-2020 William E. Lamie Modified comment(s), */
/* resulting in version 6.1 */
/* */
/**************************************************************************/
UINT _fx_fault_tolerant_recover(FX_MEDIA *media_ptr)
{
UINT status;
ULONG insertion_front;
ULONG origianl_head_cluster;
FX_FAULT_TOLERANT_FAT_CHAIN *FAT_chain;
/* Set fault tolerant state to IDLE. */
media_ptr -> fx_media_fault_tolerant_state = FX_FAULT_TOLERANT_STATE_IDLE;
/* Set FAT chain pointer. */
FAT_chain = (FX_FAULT_TOLERANT_FAT_CHAIN *)(media_ptr -> fx_media_fault_tolerant_memory_buffer + FX_FAULT_TOLERANT_FAT_CHAIN_OFFSET);
/* Whether or not the supplied FAT chain is valid. */
if (!(FAT_chain -> fx_fault_tolerant_FAT_chain_flag & FX_FAULT_TOLERANT_FLAG_FAT_CHAIN_VALID))
{
/* Invalid, which indiates the FAT chain has been cleaned up already. In this case, just return. */
return(FX_SUCCESS);
}
/* Set FAT chain pointer. */
FAT_chain = (FX_FAULT_TOLERANT_FAT_CHAIN *)(media_ptr -> fx_media_fault_tolerant_memory_buffer + FX_FAULT_TOLERANT_FAT_CHAIN_OFFSET);
/* Recover FAT chain. */
status = _fx_fault_tolerant_cleanup_FAT_chain(media_ptr, FX_FAULT_TOLERANT_FAT_CHAIN_RECOVER);
if (status != FX_SUCCESS)
{
/* Return the error status. */
return(status);
}
/* Now, link the front of the insertion point back to the origianl FAT chain. */
insertion_front = _fx_utility_32_unsigned_read((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_insertion_front);
origianl_head_cluster = _fx_utility_32_unsigned_read((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_head_original);
if (insertion_front != FX_FREE_CLUSTER)
{
/* Front of the insertion point exists. Link the origianl chain back to the front of the insertion point. */
status = _fx_utility_FAT_entry_write(media_ptr, insertion_front, origianl_head_cluster);
if (status != FX_SUCCESS)
{
/* Return the error status. */
return(status);
}
}
/* New FAT chain is always linked by FAT entries. */
/* Flush FAT table. */
#ifdef FX_FAULT_TOLERANT
/* Ensure the new FAT chain is properly written to the media. */
/* Flush the cached individual FAT entries */
_fx_utility_FAT_flush(media_ptr);
#endif
/* Return success. */
return(FX_SUCCESS);
}
#endif /* FX_ENABLE_FAULT_TOLERANT */