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

libfat.pnproj

@@ -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>

source/fatdir.c

@@ -465,6 +465,15 @@ int _FAT_statvfs_r (struct _reent *r, const char *path, struct statvfs *buf)
 
 	_FAT_lock(&partition->lock);
 
+    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

source/file_allocation_table.c

@@ -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;
 	}

source/partition.c

@@ -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)
@@ -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;
+	}
+}

source/partition.h

@@ -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
@@ -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