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support to read/write FS info sector for FAT32 partitions. speeds up statvfs. patch submitted by dimok

This commit is contained in:
tantricity 2011-01-16 19:03:37 +00:00
parent 875d47b8f3
commit 93ec6aad6a
5 changed files with 206 additions and 77 deletions
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2
libfat.pnproj
View File

@ -1 +1 @@
<Project name="libfat"><MagicFolder excludeFolders="CVS;.svn" filter="*.c;*.h" name="source" path="source\"><MagicFolder excludeFolders="CVS;.svn" filter="*.c;*.h" name="disc_io" path="disc_io\"><File path="disc.c"></File><File path="io_cf_common.c"></File><File path="io_cf_common.h"></File><File path="io_dldi.h"></File><File path="io_efa2.c"></File><File path="io_efa2.h"></File><File path="io_fcsr.c"></File><File path="io_fcsr.h"></File><File path="io_m3cf.c"></File><File path="io_m3cf.h"></File><File path="io_m3sd.c"></File><File path="io_m3sd.h"></File><File path="io_m3_common.c"></File><File path="io_m3_common.h"></File><File path="io_mpcf.c"></File><File path="io_mpcf.h"></File><File path="io_njsd.c"></File><File path="io_njsd.h"></File><File path="io_nmmc.c"></File><File path="io_nmmc.h"></File><File path="io_sccf.c"></File><File path="io_sccf.h"></File><File path="io_scsd.c"></File><File path="io_scsd.h"></File><File path="io_sc_common.c"></File><File path="io_sc_common.h"></File><File path="io_sd_common.c"></File><File path="io_sd_common.h"></File></MagicFolder><MagicFolder excludeFolders="CVS;.svn" filter="*.c;*.h" name="ogc_io" path="ogc_io\"><File path="disc.c"></File><File path="gcsd.c"></File><File path="gcsd.h"></File><File path="wiisd.c"></File><File path="wiisd.h"></File></MagicFolder><File path="bit_ops.h"></File><File path="cache.c"></File><File path="cache.h"></File><File path="common.h"></File><File path="directory.c"></File><File path="directory.h"></File><File path="disc.h"></File><File path="fatdir.c"></File><File path="fatdir.h"></File><File path="fatfile.c"></File><File path="fatfile.h"></File><File path="filetime.c"></File><File path="filetime.h"></File><File path="file_allocation_table.c"></File><File path="file_allocation_table.h"></File><File path="libfat.c"></File><File path="mem_allocate.h"></File><File path="partition.c"></File><File path="partition.h"></File></MagicFolder><Folder name="nds"><Folder name="include"><File path="nds\include\fat.h"></File><File path="nds\include\nitrofs.h"></File></Folder><Folder name="source"><File path="nds\source\nitrofs.c"></File></Folder><File path="nds\Makefile"></File></Folder><Folder name="libogc"><Folder name="include"><File path="libogc\include\fat.h"></File></Folder><File path="libogc\Makefile"></File></Folder><Folder name="gba"><Folder name="include"><File path="gba\include\fat.h"></File></Folder><File path="gba\Makefile"></File></Folder><MagicFolder excludeFolders="CVS;.svn" filter="*.h" name="include" path="include\"><File path="fat.h"></File></MagicFolder><File path="Makefile"></File></Project>
<Project name="libfat"><MagicFolder excludeFolders="CVS;.svn" filter="*.c;*.h" name="source" path="source\"><File path="bit_ops.h"></File><File path="cache.c"></File><File path="cache.h"></File><File path="common.h"></File><File path="directory.c"></File><File path="directory.h"></File><File path="disc.c"></File><File path="disc.h"></File><File path="fatdir.c"></File><File path="fatdir.h"></File><File path="fatfile.c"></File><File path="fatfile.h"></File><File path="filetime.c"></File><File path="filetime.h"></File><File path="file_allocation_table.c"></File><File path="file_allocation_table.h"></File><File path="libfat.c"></File><File path="lock.c"></File><File path="lock.h"></File><File path="mem_allocate.h"></File><File path="partition.c"></File><File path="partition.h"></File></MagicFolder><Folder name="nds"><Folder name="include"><File path="nds\include\fat.h"></File><File path="nds\include\nitrofs.h"></File></Folder><Folder name="source"><File path="nds\source\nitrofs.c"></File></Folder><File path="nds\Makefile"></File></Folder><Folder name="libogc"><Folder name="include"><File path="libogc\include\fat.h"></File></Folder><File path="libogc\Makefile"></File></Folder><Folder name="gba"><Folder name="include"><File path="gba\include\fat.h"></File></Folder><File path="gba\Makefile"></File></Folder><MagicFolder excludeFolders="CVS;.svn" filter="*.h" name="include" path="include\"><File path="fat.h"></File><File path="libfatversion.h"></File></MagicFolder><File path="Makefile"></File></Project>

155
source/fatdir.c
View File

@ -1,11 +1,11 @@
/*
fatdir.c
Functions used by the newlib disc stubs to interface with
Functions used by the newlib disc stubs to interface with
this library
Copyright (c) 2006 Michael "Chishm" Chisholm
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:
@ -48,7 +48,7 @@
int _FAT_stat_r (struct _reent *r, const char *path, struct stat *st) {
PARTITION* partition = NULL;
DIR_ENTRY dirEntry;
// Get the partition this file is on
partition = _FAT_partition_getPartitionFromPath (path);
if (partition == NULL) {
@ -73,10 +73,10 @@ int _FAT_stat_r (struct _reent *r, const char *path, struct stat *st) {
r->_errno = ENOENT;
return -1;
}
// Fill in the stat struct
_FAT_directory_entryStat (partition, &dirEntry, st);
_FAT_unlock(&partition->lock);
return 0;
}
@ -93,7 +93,7 @@ int _FAT_unlink_r (struct _reent *r, const char *path) {
uint32_t cluster;
bool nextEntry;
bool errorOccured = false;
// Get the partition this directory is on
partition = _FAT_partition_getPartitionFromPath (path);
if (partition == NULL) {
@ -105,7 +105,7 @@ int _FAT_unlink_r (struct _reent *r, const char *path) {
if (partition->readOnly) {
r->_errno = EROFS;
return -1;
}
}
// Move the path pointer to the start of the actual path
if (strchr (path, ':') != NULL) {
@ -115,23 +115,23 @@ int _FAT_unlink_r (struct _reent *r, const char *path) {
r->_errno = EINVAL;
return -1;
}
_FAT_lock(&partition->lock);
// Search for the file on the disc
if (!_FAT_directory_entryFromPath (partition, &dirEntry, path, NULL)) {
_FAT_unlock(&partition->lock);
r->_errno = ENOENT;
return -1;
}
cluster = _FAT_directory_entryGetCluster (partition, dirEntry.entryData);
// If this is a directory, make sure it is empty
if (_FAT_directory_isDirectory (&dirEntry)) {
nextEntry = _FAT_directory_getFirstEntry (partition, &dirContents, cluster);
while (nextEntry) {
if (!_FAT_directory_isDot (&dirContents)) {
// The directory had something in it that isn't a reference to itself or it's parent
@ -156,13 +156,13 @@ int _FAT_unlink_r (struct _reent *r, const char *path) {
r->_errno = EIO;
errorOccured = true;
}
// Flush any sectors in the disc cache
if (!_FAT_cache_flush(partition->cache)) {
r->_errno = EIO;
errorOccured = true;
}
_FAT_unlock(&partition->lock);
if (errorOccured) {
return -1;
@ -173,7 +173,7 @@ int _FAT_unlink_r (struct _reent *r, const char *path) {
int _FAT_chdir_r (struct _reent *r, const char *path) {
PARTITION* partition = NULL;
// Get the partition this directory is on
partition = _FAT_partition_getPartitionFromPath (path);
if (partition == NULL) {
@ -189,7 +189,7 @@ int _FAT_chdir_r (struct _reent *r, const char *path) {
r->_errno = EINVAL;
return -1;
}
_FAT_lock(&partition->lock);
// Try changing directory
@ -211,16 +211,16 @@ int _FAT_rename_r (struct _reent *r, const char *oldName, const char *newName) {
DIR_ENTRY newDirEntry;
const char *pathEnd;
uint32_t dirCluster;
// Get the partition this directory is on
partition = _FAT_partition_getPartitionFromPath (oldName);
if (partition == NULL) {
r->_errno = ENODEV;
return -1;
}
_FAT_lock(&partition->lock);
// Make sure the same partition is used for the old and new names
if (partition != _FAT_partition_getPartitionFromPath (newName)) {
_FAT_unlock(&partition->lock);
@ -233,7 +233,7 @@ int _FAT_rename_r (struct _reent *r, const char *oldName, const char *newName) {
_FAT_unlock(&partition->lock);
r->_errno = EROFS;
return -1;
}
}
// Move the path pointer to the start of the actual path
if (strchr (oldName, ':') != NULL) {
@ -259,7 +259,7 @@ int _FAT_rename_r (struct _reent *r, const char *oldName, const char *newName) {
r->_errno = ENOENT;
return -1;
}
// Make sure there is no existing file / directory with the new name
if (_FAT_directory_entryFromPath (partition, &newDirEntry, newName, NULL)) {
_FAT_unlock(&partition->lock);
@ -268,7 +268,7 @@ int _FAT_rename_r (struct _reent *r, const char *oldName, const char *newName) {
}
// Create the new file entry
// Get the directory it has to go in
// Get the directory it has to go in
pathEnd = strrchr (newName, DIR_SEPARATOR);
if (pathEnd == NULL) {
// No path was specified
@ -290,24 +290,24 @@ int _FAT_rename_r (struct _reent *r, const char *oldName, const char *newName) {
// Copy the entry data
memcpy (&newDirEntry, &oldDirEntry, sizeof(DIR_ENTRY));
// Set the new name
strncpy (newDirEntry.filename, pathEnd, MAX_FILENAME_LENGTH - 1);
// Write the new entry
if (!_FAT_directory_addEntry (partition, &newDirEntry, dirCluster)) {
_FAT_unlock(&partition->lock);
r->_errno = ENOSPC;
return -1;
}
// Remove the old entry
if (!_FAT_directory_removeEntry (partition, &oldDirEntry)) {
_FAT_unlock(&partition->lock);
r->_errno = EIO;
return -1;
}
// Flush any sectors in the disc cache
if (!_FAT_cache_flush (partition->cache)) {
_FAT_unlock(&partition->lock);
@ -341,27 +341,27 @@ int _FAT_mkdir_r (struct _reent *r, const char *path, int mode) {
r->_errno = EINVAL;
return -1;
}
_FAT_lock(&partition->lock);
// Search for the file/directory on the disc
fileExists = _FAT_directory_entryFromPath (partition, &dirEntry, path, NULL);
// Make sure it doesn't exist
if (fileExists) {
_FAT_unlock(&partition->lock);
r->_errno = EEXIST;
return -1;
}
if (partition->readOnly) {
// We can't write to a read-only partition
_FAT_unlock(&partition->lock);
r->_errno = EROFS;
return -1;
}
// Get the directory it has to go in
}
// Get the directory it has to go in
pathEnd = strrchr (path, DIR_SEPARATOR);
if (pathEnd == NULL) {
// No path was specified
@ -383,7 +383,7 @@ int _FAT_mkdir_r (struct _reent *r, const char *path, int mode) {
// Create the entry data
strncpy (dirEntry.filename, pathEnd, MAX_FILENAME_LENGTH - 1);
memset (dirEntry.entryData, 0, DIR_ENTRY_DATA_SIZE);
// Set the creation time and date
dirEntry.entryData[DIR_ENTRY_cTime_ms] = 0;
u16_to_u8array (dirEntry.entryData, DIR_ENTRY_cTime, _FAT_filetime_getTimeFromRTC());
@ -391,10 +391,10 @@ int _FAT_mkdir_r (struct _reent *r, const char *path, int mode) {
u16_to_u8array (dirEntry.entryData, DIR_ENTRY_mTime, _FAT_filetime_getTimeFromRTC());
u16_to_u8array (dirEntry.entryData, DIR_ENTRY_mDate, _FAT_filetime_getDateFromRTC());
u16_to_u8array (dirEntry.entryData, DIR_ENTRY_aDate, _FAT_filetime_getDateFromRTC());
// Set the directory attribute
dirEntry.entryData[DIR_ENTRY_attributes] = ATTRIB_DIR;
// Get a cluster for the new directory
dirCluster = _FAT_fat_linkFreeClusterCleared (partition, CLUSTER_FREE);
if (!_FAT_fat_isValidCluster(partition, dirCluster)) {
@ -412,7 +412,7 @@ int _FAT_mkdir_r (struct _reent *r, const char *path, int mode) {
r->_errno = ENOSPC;
return -1;
}
// Create the dot entry within the directory
memset (newEntryData, 0, DIR_ENTRY_DATA_SIZE);
memset (newEntryData, ' ', 11);
@ -420,12 +420,12 @@ int _FAT_mkdir_r (struct _reent *r, const char *path, int mode) {
newEntryData[DIR_ENTRY_attributes] = ATTRIB_DIR;
u16_to_u8array (newEntryData, DIR_ENTRY_cluster, dirCluster);
u16_to_u8array (newEntryData, DIR_ENTRY_clusterHigh, dirCluster >> 16);
// Write it to the directory, erasing that sector in the process
_FAT_cache_eraseWritePartialSector ( partition->cache, newEntryData,
_FAT_cache_eraseWritePartialSector ( partition->cache, newEntryData,
_FAT_fat_clusterToSector (partition, dirCluster), 0, DIR_ENTRY_DATA_SIZE);
// Create the double dot entry within the directory
// if ParentDir == Rootdir then ".."" always link to Cluster 0
@ -437,7 +437,7 @@ int _FAT_mkdir_r (struct _reent *r, const char *path, int mode) {
u16_to_u8array (newEntryData, DIR_ENTRY_clusterHigh, parentCluster >> 16);
// Write it to the directory
_FAT_cache_writePartialSector ( partition->cache, newEntryData,
_FAT_cache_writePartialSector ( partition->cache, newEntryData,
_FAT_fat_clusterToSector (partition, dirCluster), DIR_ENTRY_DATA_SIZE, DIR_ENTRY_DATA_SIZE);
// Flush any sectors in the disc cache
@ -451,7 +451,7 @@ int _FAT_mkdir_r (struct _reent *r, const char *path, int mode) {
return 0;
}
int _FAT_statvfs_r (struct _reent *r, const char *path, struct statvfs *buf)
int _FAT_statvfs_r (struct _reent *r, const char *path, struct statvfs *buf)
{
PARTITION* partition = NULL;
unsigned int freeClusterCount;
@ -465,29 +465,38 @@ int _FAT_statvfs_r (struct _reent *r, const char *path, struct statvfs *buf)
_FAT_lock(&partition->lock);
freeClusterCount = _FAT_fat_freeClusterCount (partition);
if(memcmp(&buf->f_flag, "SCAN", 4) == 0)
{
//Special command was given to sync the numberFreeCluster
_FAT_partition_createFSinfo(partition);
}
if(partition->filesysType == FS_FAT32)
freeClusterCount = partition->fat.numberFreeCluster;
else
freeClusterCount = _FAT_fat_freeClusterCount (partition);
// FAT clusters = POSIX blocks
buf->f_bsize = partition->bytesPerCluster; // File system block size.
buf->f_frsize = partition->bytesPerCluster; // Fundamental file system block size.
buf->f_blocks = partition->fat.lastCluster - CLUSTER_FIRST + 1; // Total number of blocks on file system in units of f_frsize.
buf->f_bfree = freeClusterCount; // Total number of free blocks.
buf->f_bavail = freeClusterCount; // Number of free blocks available to non-privileged process.
buf->f_bsize = partition->bytesPerCluster; // File system block size.
buf->f_frsize = partition->bytesPerCluster; // Fundamental file system block size.
buf->f_blocks = partition->fat.lastCluster - CLUSTER_FIRST + 1; // Total number of blocks on file system in units of f_frsize.
buf->f_bfree = freeClusterCount; // Total number of free blocks.
buf->f_bavail = freeClusterCount; // Number of free blocks available to non-privileged process.
// Treat requests for info on inodes as clusters
buf->f_files = partition->fat.lastCluster - CLUSTER_FIRST + 1; // Total number of file serial numbers.
buf->f_ffree = freeClusterCount; // Total number of free file serial numbers.
buf->f_favail = freeClusterCount; // Number of file serial numbers available to non-privileged process.
buf->f_files = partition->fat.lastCluster - CLUSTER_FIRST + 1; // Total number of file serial numbers.
buf->f_ffree = freeClusterCount; // Total number of free file serial numbers.
buf->f_favail = freeClusterCount; // Number of file serial numbers available to non-privileged process.
// File system ID. 32bit ioType value
buf->f_fsid = _FAT_disc_hostType(partition->disc);
buf->f_fsid = _FAT_disc_hostType(partition->disc);
// Bit mask of f_flag values.
buf->f_flag = ST_NOSUID /* No support for ST_ISUID and ST_ISGID file mode bits */
| (partition->readOnly ? ST_RDONLY /* Read only file system */ : 0 ) ;
// Maximum filename length.
buf->f_namemax = MAX_FILENAME_LENGTH;
buf->f_namemax = MAX_FILENAME_LENGTH;
_FAT_unlock(&partition->lock);
return 0;
@ -497,7 +506,7 @@ DIR_ITER* _FAT_diropen_r(struct _reent *r, DIR_ITER *dirState, const char *path)
DIR_ENTRY dirEntry;
DIR_STATE_STRUCT* state = (DIR_STATE_STRUCT*) (dirState->dirStruct);
bool fileExists;
state->partition = _FAT_partition_getPartitionFromPath (path);
if (state->partition == NULL) {
r->_errno = ENODEV;
@ -512,18 +521,18 @@ DIR_ITER* _FAT_diropen_r(struct _reent *r, DIR_ITER *dirState, const char *path)
r->_errno = EINVAL;
return NULL;
}
_FAT_lock(&state->partition->lock);
// Get the start cluster of the directory
fileExists = _FAT_directory_entryFromPath (state->partition, &dirEntry, path, NULL);
if (!fileExists) {
_FAT_unlock(&state->partition->lock);
r->_errno = ENOENT;
return NULL;
}
// Make sure it is a directory
if (! _FAT_directory_isDirectory (&dirEntry)) {
_FAT_unlock(&state->partition->lock);
@ -533,11 +542,11 @@ DIR_ITER* _FAT_diropen_r(struct _reent *r, DIR_ITER *dirState, const char *path)
// Save the start cluster for use when resetting the directory data
state->startCluster = _FAT_directory_entryGetCluster (state->partition, dirEntry.entryData);
// Get the first entry for use with a call to dirnext
state->validEntry =
state->validEntry =
_FAT_directory_getFirstEntry (state->partition, &(state->currentEntry), state->startCluster);
// We are now using this entry
state->inUse = true;
_FAT_unlock(&state->partition->lock);
@ -548,7 +557,7 @@ int _FAT_dirreset_r (struct _reent *r, DIR_ITER *dirState) {
DIR_STATE_STRUCT* state = (DIR_STATE_STRUCT*) (dirState->dirStruct);
_FAT_lock(&state->partition->lock);
// Make sure we are still using this entry
if (!state->inUse) {
_FAT_unlock(&state->partition->lock);
@ -557,7 +566,7 @@ int _FAT_dirreset_r (struct _reent *r, DIR_ITER *dirState) {
}
// Get the first entry for use with a call to dirnext
state->validEntry =
state->validEntry =
_FAT_directory_getFirstEntry (state->partition, &(state->currentEntry), state->startCluster);
_FAT_unlock(&state->partition->lock);
@ -568,14 +577,14 @@ int _FAT_dirnext_r (struct _reent *r, DIR_ITER *dirState, char *filename, struct
DIR_STATE_STRUCT* state = (DIR_STATE_STRUCT*) (dirState->dirStruct);
_FAT_lock(&state->partition->lock);
// Make sure we are still using this entry
if (!state->inUse) {
_FAT_unlock(&state->partition->lock);
r->_errno = EBADF;
return -1;
}
// Make sure there is another file to report on
if (! state->validEntry) {
_FAT_unlock(&state->partition->lock);
@ -589,9 +598,9 @@ int _FAT_dirnext_r (struct _reent *r, DIR_ITER *dirState, char *filename, struct
if (filestat != NULL) {
_FAT_directory_entryStat (state->partition, &(state->currentEntry), filestat);
}
// Look for the next entry for use next time
state->validEntry =
state->validEntry =
_FAT_directory_getNextEntry (state->partition, &(state->currentEntry));
_FAT_unlock(&state->partition->lock);
@ -600,7 +609,7 @@ int _FAT_dirnext_r (struct _reent *r, DIR_ITER *dirState, char *filename, struct
int _FAT_dirclose_r (struct _reent *r, DIR_ITER *dirState) {
DIR_STATE_STRUCT* state = (DIR_STATE_STRUCT*) (dirState->dirStruct);
// We are no longer using this entry
_FAT_lock(&state->partition->lock);
state->inUse = false;

5
source/file_allocation_table.c
View File

@ -245,6 +245,9 @@ uint32_t _FAT_fat_linkFreeCluster(PARTITION* partition, uint32_t cluster) {
}
}
partition->fat.firstFree = firstFree;
if(partition->fat.numberFreeCluster)
partition->fat.numberFreeCluster--;
partition->fat.numberLastAllocCluster = firstFree;
if ((cluster >= CLUSTER_FIRST) && (cluster <= lastCluster))
{
@ -309,6 +312,8 @@ bool _FAT_fat_clearLinks (PARTITION* partition, uint32_t cluster) {
// Erase the link
_FAT_fat_writeFatEntry (partition, cluster, CLUSTER_FREE);
if(partition->fat.numberFreeCluster < (partition->numberOfSectors/partition->sectorsPerCluster))
partition->fat.numberFreeCluster++;
// Move onto next cluster
cluster = nextCluster;
}

99
source/partition.c
View File

@ -93,7 +93,20 @@ enum BPB {
BPB_bootSig_AA = 0x1FF
};
// File system information block offsets
enum FSIB
{
FSIB_SIG1 = 0x00,
FSIB_SIG2 = 0x1e4,
FSIB_numberOfFreeCluster = 0x1e8,
FSIB_numberLastAllocCluster = 0x1ec,
FSIB_bootSig_55 = 0x1FE,
FSIB_bootSig_AA = 0x1FF
};
static const char FAT_SIG[3] = {'F', 'A', 'T'};
static const char FS_INFO_SIG1[4] = {'R', 'R', 'a', 'A'};
static const char FS_INFO_SIG2[4] = {'r', 'r', 'A', 'a'};
sec_t FindFirstValidPartition(const DISC_INTERFACE* disc)
@ -163,7 +176,7 @@ PARTITION* _FAT_partition_constructor (const DISC_INTERFACE* disc, uint32_t cach
if (!_FAT_disc_readSectors (disc, startSector, 1, sectorBuffer)) {
return NULL;
}
// Make sure it is a valid MBR or boot sector
if ( (sectorBuffer[BPB_bootSig_55] != 0x55) || (sectorBuffer[BPB_bootSig_AA] != 0xAA)) {
return NULL;
@ -230,10 +243,15 @@ PARTITION* _FAT_partition_constructor (const DISC_INTERFACE* disc, uint32_t cach
partition->totalSize = ((uint64_t)partition->numberOfSectors - (partition->dataStart - startSector)) * (uint64_t)partition->bytesPerSector;
//FS info sector
partition->fsInfoSector = startSector + (u8array_to_u16(sectorBuffer, BPB_FAT32_fsInfo) ? u8array_to_u16(sectorBuffer, BPB_FAT32_fsInfo) : 1);
// Store info about FAT
uint32_t clusterCount = (partition->numberOfSectors - (uint32_t)(partition->dataStart - startSector)) / partition->sectorsPerCluster;
partition->fat.lastCluster = clusterCount + CLUSTER_FIRST - 1;
partition->fat.firstFree = CLUSTER_FIRST;
partition->fat.numberFreeCluster = 0;
partition->fat.numberLastAllocCluster = 0;
if (clusterCount < CLUSTERS_PER_FAT12) {
partition->filesysType = FS_FAT12; // FAT12 volume
@ -268,6 +286,8 @@ PARTITION* _FAT_partition_constructor (const DISC_INTERFACE* disc, uint32_t cach
partition->openFileCount = 0;
partition->firstOpenFile = NULL;
_FAT_partition_readFSinfo(partition);
return partition;
}
@ -283,6 +303,9 @@ void _FAT_partition_destructor (PARTITION* partition) {
nextFile = nextFile->nextOpenFile;
}
// Write out the fs info sector
_FAT_partition_writeFSinfo(partition);
// Free memory used by the cache, writing it to disc at the same time
_FAT_cache_destructor (partition->cache);
@ -305,3 +328,77 @@ PARTITION* _FAT_partition_getPartitionFromPath (const char* path) {
return (PARTITION*)devops->deviceData;
}
void _FAT_partition_createFSinfo(PARTITION * partition)
{
if(partition->readOnly || partition->filesysType != FS_FAT32)
return;
uint8_t sectorBuffer[BYTES_PER_READ];
memset(sectorBuffer, 0, sizeof(sectorBuffer));
int i;
for(i = 0; i < 4; ++i)
{
sectorBuffer[FSIB_SIG1+i] = FS_INFO_SIG1[i];
sectorBuffer[FSIB_SIG2+i] = FS_INFO_SIG2[i];
}
partition->fat.numberFreeCluster = _FAT_fat_freeClusterCount(partition);
u32_to_u8array(sectorBuffer, FSIB_numberOfFreeCluster, partition->fat.numberFreeCluster);
u32_to_u8array(sectorBuffer, FSIB_numberLastAllocCluster, partition->fat.numberLastAllocCluster);
sectorBuffer[FSIB_bootSig_55] = 0x55;
sectorBuffer[FSIB_bootSig_AA] = 0xAA;
_FAT_disc_writeSectors (partition->disc, partition->fsInfoSector, 1, sectorBuffer);
}
void _FAT_partition_readFSinfo(PARTITION * partition)
{
if(partition->filesysType != FS_FAT32)
return;
uint8_t sectorBuffer[BYTES_PER_READ] = {0};
// Read first sector of disc
if (!_FAT_disc_readSectors (partition->disc, partition->fsInfoSector, 1, sectorBuffer)) {
return;
}
if(memcmp(sectorBuffer+FSIB_SIG1, FS_INFO_SIG1, 4) != 0 ||
memcmp(sectorBuffer+FSIB_SIG2, FS_INFO_SIG2, 4) != 0 ||
u8array_to_u32(sectorBuffer, FSIB_numberOfFreeCluster) == 0)
{
//sector does not yet exist, create one!
_FAT_partition_createFSinfo(partition);
return;
}
partition->fat.numberFreeCluster = u8array_to_u32(sectorBuffer, FSIB_numberOfFreeCluster);
partition->fat.numberLastAllocCluster = u8array_to_u32(sectorBuffer, FSIB_numberLastAllocCluster);
}
void _FAT_partition_writeFSinfo(PARTITION * partition)
{
if(partition->filesysType != FS_FAT32)
return;
uint8_t sectorBuffer[BYTES_PER_READ] = {0};
// Read first sector of disc
if (!_FAT_disc_readSectors (partition->disc, partition->fsInfoSector, 1, sectorBuffer)) {
return;
}
if(memcmp(sectorBuffer+FSIB_SIG1, FS_INFO_SIG1, 4) || memcmp(sectorBuffer+FSIB_SIG2, FS_INFO_SIG2, 4))
return;
u32_to_u8array(sectorBuffer, FSIB_numberOfFreeCluster, partition->fat.numberFreeCluster);
u32_to_u8array(sectorBuffer, FSIB_numberLastAllocCluster, partition->fat.numberLastAllocCluster);
// Read first sector of disc
if (!_FAT_disc_writeSectors (partition->disc, partition->fsInfoSector, 1, sectorBuffer)) {
return;
}
}

22
source/partition.h
View File

@ -4,7 +4,7 @@
on various block devices.
Copyright (c) 2006 Michael "Chishm" Chisholm
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:
@ -45,6 +45,8 @@ typedef struct {
uint32_t sectorsPerFat;
uint32_t lastCluster;
uint32_t firstFree;
uint32_t numberFreeCluster;
uint32_t numberLastAllocCluster;
} FAT;
typedef struct {
@ -60,6 +62,7 @@ typedef struct {
uint32_t bytesPerSector;
uint32_t sectorsPerCluster;
uint32_t bytesPerCluster;
uint32_t fsInfoSector;
FAT fat;
// Values that may change after construction
uint32_t cwdCluster; // Current working directory cluster
@ -76,7 +79,7 @@ Mount the supplied device and return a pointer to the struct necessary to use it
PARTITION* _FAT_partition_constructor (const DISC_INTERFACE* disc, uint32_t cacheSize, uint32_t SectorsPerPage, sec_t startSector);
/*
Dismount the device and free all structures used.
Dismount the device and free all structures used.
Will also attempt to synchronise all open files to disc.
*/
void _FAT_partition_destructor (PARTITION* partition);
@ -86,4 +89,19 @@ Return the partition specified in a path, as taken from the devoptab.
*/
PARTITION* _FAT_partition_getPartitionFromPath (const char* path);
/*
Create the fs info sector.
*/
void _FAT_partition_createFSinfo(PARTITION * partition);
/*
Read the fs info sector data.
*/
void _FAT_partition_readFSinfo(PARTITION * partition);
/*
Write the fs info sector data.
*/
void _FAT_partition_writeFSinfo(PARTITION * partition);
#endif // _PARTITION_H