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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 */
/** */
/** Utility */
/** */
/**************************************************************************/
/**************************************************************************/
#define FX_SOURCE_CODE
/* Include necessary system files. */
#include "fx_api.h"
#include "fx_system.h"
#include "fx_utility.h"
#ifdef FX_ENABLE_FAULT_TOLERANT
#include "fx_fault_tolerant.h"
#endif /* FX_ENABLE_FAULT_TOLERANT */
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _fx_utility_FAT_entry_write PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function writes to the supplied FAT entry to all FATs in */
/* the media. 12-bit, 16-bit, and 32-bit FAT writing is supported. */
/* */
/* INPUT */
/* */
/* media_ptr Media control block pointer */
/* cluster Cluster entry number */
/* next_cluster Next cluster integer pointer */
/* */
/* OUTPUT */
/* */
/* return status */
/* */
/* CALLS */
/* */
/* _fx_utility_FAT_flush FLUSH dirty entries in the */
/* FAT cache */
/* _fx_fault_tolerant_add_fat_log Add FAT redo log */
/* */
/* CALLED BY */
/* */
/* FileX System Functions */
/* */
/* 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_utility_FAT_entry_write(FX_MEDIA *media_ptr, ULONG cluster, ULONG next_cluster)
{
UINT status, index, i;
FX_FAT_CACHE_ENTRY *cache_entry_ptr;
#ifdef FX_ENABLE_FAULT_TOLERANT
ULONG FAT_sector;
/* While fault_tolerant is enabled, only FAT entries in the same sector are allowed to be cached. */
/* We must flush FAT sectors in the order of FAT chains. */
if (media_ptr -> fx_media_fault_tolerant_enabled &&
(media_ptr -> fx_media_fault_tolerant_state & FX_FAULT_TOLERANT_STATE_STARTED))
{
if (!(media_ptr -> fx_media_fault_tolerant_state & FX_FAULT_TOLERANT_STATE_SET_FAT_CHAIN))
{
/* Redirect this request to log file. */
return(_fx_fault_tolerant_add_FAT_log(media_ptr, cluster, next_cluster));
}
/* Get sector number of the incoming FAT entry. */
FAT_sector = _fx_utility_FAT_sector_get(media_ptr, cluster);
/* Is FAT sector changed? */
if (FAT_sector != media_ptr -> fx_media_fault_tolerant_cached_FAT_sector)
{
/* Are there any cached FAT entries? */
if (media_ptr -> fx_media_fault_tolerant_cached_FAT_sector)
{
/* Current FAT entry is located in different sector. Force flush. */
/* Flush the cached individual FAT entries */
_fx_utility_FAT_flush(media_ptr);
#ifdef FX_ENABLE_EXFAT
if (media_ptr -> fx_media_FAT_type == FX_exFAT)
{
/* Flush exFAT bitmap. */
_fx_utility_exFAT_bitmap_flush(media_ptr);
}
#endif /* FX_ENABLE_EXFAT */
}
/* Record sector number of current FAT entry. */
media_ptr -> fx_media_fault_tolerant_cached_FAT_sector = FAT_sector;
}
}
#endif /* FX_ENABLE_FAULT_TOLERANT */
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Increment the number of FAT entry writes and cache hits. */
media_ptr -> fx_media_fat_entry_writes++;
media_ptr -> fx_media_fat_entry_cache_write_hits++;
#endif
/* Extended port-specific processing macro, which is by default defined to white space. */
FX_UTILITY_FAT_ENTRY_WRITE_EXTENSION
/* Calculate the area of the cache for this FAT entry. */
index = (cluster & FX_FAT_CACHE_HASH_MASK) * FX_FAT_CACHE_DEPTH;
/* Build a pointer to the cache entry. */
cache_entry_ptr = &media_ptr -> fx_media_fat_cache[index];
/* First search for the entry in the FAT entry cache. */
for (i = 0; i < FX_FAT_CACHE_DEPTH; i++)
{
/* See if the entry matches the write request. */
if (((cache_entry_ptr + i) -> fx_fat_cache_entry_cluster) == cluster)
{
/* Yes, we have a matching entry. Save the new information in the FAT
cache and mark this entry as dirty. */
(cache_entry_ptr + i) -> fx_fat_cache_entry_value = next_cluster;
(cache_entry_ptr + i) -> fx_fat_cache_entry_dirty = 1;
/* Determine if the driver has requested notification when data sectors in the media
become free. This can be useful to FLASH manager software. */
if ((media_ptr -> fx_media_driver_free_sector_update) && (next_cluster == FX_FREE_CLUSTER))
{
/* Yes, the driver does wish to know that these specific sector(s) are
not in use. */
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Increment the number of driver release sectors requests. */
media_ptr -> fx_media_driver_release_sectors_requests++;
#endif
/* This cluster is being released so inform the driver that the
corresponding sectors are now available. */
media_ptr -> fx_media_driver_request = FX_DRIVER_RELEASE_SECTORS;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
media_ptr -> fx_media_driver_logical_sector = (media_ptr -> fx_media_data_sector_start +
((cluster - FX_FAT_ENTRY_START) * media_ptr -> fx_media_sectors_per_cluster));
media_ptr -> fx_media_driver_sectors = media_ptr -> fx_media_sectors_per_cluster;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_RELEASE_SECTORS, media_ptr, media_ptr -> fx_media_driver_logical_sector, media_ptr -> fx_media_driver_sectors, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Call the driver. */
(media_ptr -> fx_media_driver_entry)(media_ptr);
}
/* Done, return successful status. */
return(FX_SUCCESS);
}
}
/* If we reach this point, we know that the FAT write request is not in
the cache. */
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Decrement the number of cache hits. */
media_ptr -> fx_media_fat_entry_cache_write_hits--;
/* Increment the number of cache misses. */
media_ptr -> fx_media_fat_entry_cache_write_misses++;
#endif
/* Determine if the oldest entry is dirty and needs to be flushed. */
if (media_ptr -> fx_media_fat_cache[index + 3].fx_fat_cache_entry_dirty == 1)
{
/* Flush the dirty entry so it can be used to hold the current
FAT entry write request. */
status = _fx_utility_FAT_flush(media_ptr);
/* Determine if the write was successful. */
if (status != FX_SUCCESS)
{
/* No, return error status to caller. */
return(status);
}
}
/* Move all the cache entries down so the oldest is at the bottom. */
*(cache_entry_ptr + 3) = *(cache_entry_ptr + 2);
*(cache_entry_ptr + 2) = *(cache_entry_ptr + 1);
*(cache_entry_ptr + 1) = *(cache_entry_ptr);
/* Save the current FAT entry write request and mark as dirty. */
cache_entry_ptr -> fx_fat_cache_entry_dirty = 1;
cache_entry_ptr -> fx_fat_cache_entry_cluster = cluster;
cache_entry_ptr -> fx_fat_cache_entry_value = next_cluster;
/* Determine if the driver has requested notification when data sectors in the media
become free. This can be useful to FLASH manager software. */
if ((media_ptr -> fx_media_driver_free_sector_update) && (next_cluster == FX_FREE_CLUSTER))
{
/* Yes, the driver does wish to know that these specific sector(s) are
not in use. */
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Increment the number of driver release sectors requests. */
media_ptr -> fx_media_driver_release_sectors_requests++;
#endif
/* This cluster is being released so inform the driver that the
corresponding sectors are now available. */
media_ptr -> fx_media_driver_request = FX_DRIVER_RELEASE_SECTORS;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
media_ptr -> fx_media_driver_logical_sector = (media_ptr -> fx_media_data_sector_start +
((cluster - FX_FAT_ENTRY_START) * media_ptr -> fx_media_sectors_per_cluster));
media_ptr -> fx_media_driver_sectors = media_ptr -> fx_media_sectors_per_cluster;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_RELEASE_SECTORS, media_ptr, media_ptr -> fx_media_driver_logical_sector, media_ptr -> fx_media_driver_sectors, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Call the driver. */
(media_ptr -> fx_media_driver_entry)(media_ptr);
}
/* Return success to caller. */
return(FX_SUCCESS);
}