1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/kernelhwsrv/userlibandfileserver/fileserver/sfat32/inc/sl_scandrv.h Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,187 @@
1.4 +// Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
1.5 +// All rights reserved.
1.6 +// This component and the accompanying materials are made available
1.7 +// under the terms of the License "Eclipse Public License v1.0"
1.8 +// which accompanies this distribution, and is available
1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
1.10 +//
1.11 +// Initial Contributors:
1.12 +// Nokia Corporation - initial contribution.
1.13 +//
1.14 +// Contributors:
1.15 +//
1.16 +// Description:
1.17 +// f32\sfat\inc\sl_scandrv.h
1.18 +//
1.19 +//
1.20 +
1.21 +/**
1.22 + @file
1.23 + @internalTechnology
1.24 +*/
1.25 +
1.26 +#ifndef SL_SCANDRV_H
1.27 +#define SL_SCANDRV_H
1.28 +
1.29 +#include "sl_std.h"
1.30 +
1.31 +//---------------------------------------------------------------------------------------------------------------------------------
1.32 +
1.33 +const TUint KMaxMatchingEntries = 2; ///< Maximum number of matching directory entries scan drive can fix. Any more indicates a fault in the file system
1.34 +const TUint KMaxArrayDepth = 6; ///< Maximum array depth for cluster storage when KMaxScanDepth is reached
1.35 +
1.36 +/** Data structure used to store the location of a partial VFat entry */
1.37 +struct TPartVFatEntry
1.38 + {
1.39 + TEntryPos iEntryPos; ///< The position of the partial VFat entry
1.40 + TFatDirEntry iEntry; ///< The Dos entry The VFat entries belong with
1.41 + };
1.42 +
1.43 +
1.44 +/** Data structure used to store the locations of entries with matching start cluster numbers. */
1.45 +struct TMatchingStartCluster
1.46 + {
1.47 + TEntryPos iEntries[KMaxMatchingEntries]; ///< The positions of the matching entries
1.48 + TUint iCount; ///< Count of matching entries
1.49 + TUint iStartCluster; ///< The matching cluster number found in more than one entry
1.50 + };
1.51 +
1.52 +
1.53 +//---------------------------------------------------------------------------------------------------------------------------------
1.54 +/**
1.55 + This class is used for checking volume for FS errors and fixing a limited set of FS artefacts introduced by Rugged FAT on write failures.
1.56 + It can operate in 2 modes:
1.57 +
1.58 + 1. "ScanDrive" mode, scan whole volume for possible Rugged FAT artefacts and fix them if possible.
1.59 + 1.1 If there was no problem at all, then StartL() finishes normally and ProblemsDiscovered() returns ENoErrors.
1.60 + 1.2 If there was Rugged FAT artefact and it had been successfully fixed, StartL() finishes normally and ProblemsDiscovered() returns EScanDriveDirError.
1.61 + In this case the client may perform volum remounting, because FAT is very likely to have been changed.
1.62 + 1.3 If there was a fatal error, like media failure or unfixable FS problem, StartL() will leave with some generic error code.
1.63 +
1.64 + 2. "CheckDisk" mode. check file system for known artefacts and return an error if _any_ problem discovered.
1.65 + In this case StartL() _may_ leave with something like KErrCorrupt if there was a media failure or scan has stumbled across unknown FS error,
1.66 + ProblemsDiscovered() _may_ return some code describing the problem. If StartL() did not leave, but ProblemsDiscovered() returns a code different
1.67 + from ENoErrors, this means that there is FS corruption.
1.68 +*/
1.69 +class CScanDrive : public CBase
1.70 + {
1.71 +
1.72 +public:
1.73 +
1.74 + ~CScanDrive();
1.75 + static CScanDrive* NewL(CFatMountCB* aMount);
1.76 + void ConstructL(CFatMountCB* aMount);
1.77 +
1.78 +public:
1.79 +
1.80 + /** description of known problems that this scanned can deal with. Mostly used in "CheckDisk " mode */
1.81 + enum TGenericError
1.82 + {
1.83 + ENoErrors = 0, ///< 0 no errors discovered
1.84 + EBadClusterNumber, ///< 1 cluster number that doesn't correspond to the max. amount of clusters on the volume
1.85 + EClusterAlreadyInUse, ///< 2 cross-linked cluster chain
1.86 + EBadClusterValue, ///< 3 also means "lost cluster"
1.87 + EInvalidEntrySize, ///< 4 size of file/directory does not correspond to the cluster chain length
1.88 +
1.89 + EUnknownError = 95, ///< unknown error
1.90 +
1.91 + EScanDriveDirError=100 ///< 100 ScanDrive error
1.92 + };
1.93 +
1.94 + TGenericError ProblemsDiscovered() const;
1.95 +
1.96 + /** CScanDrive mode of operation */
1.97 + enum TScanDriveMode
1.98 + {
1.99 + EScanAndFix, ///< "ScanDrive" mode, scan whole volume for possible Rugged FAT artefacts and fix them
1.100 + ECheckDisk, ///< "CheckDisk" mode. check file system for known artefacts and return an error if _any_ problem discovered
1.101 + };
1.102 +
1.103 + void StartL(TScanDriveMode aMode);
1.104 +
1.105 +private:
1.106 + void PrintErrors();
1.107 + void CompareFatsL(TBool aStopOnFirstErrorFound) ;
1.108 + void CompareAndFixFatsL();
1.109 +
1.110 + void FixupDirErrorL();
1.111 +
1.112 + void ReadMediaFatL();
1.113 + void DoParseFatL();
1.114 + void DoParseFat32L();
1.115 + void DoParseFat32Buf(const TPtrC8& aBuf, TUint32& aCurrFatEntry);
1.116 +
1.117 + TBool IsClusterUsedL(TUint aCluster);
1.118 + void MarkClusterUsedL(TUint aCluster);
1.119 +
1.120 + TUint32 ReadFatL(TUint aClusterNum) ;
1.121 + void FindSameStartClusterL();
1.122 + TInt FindStartClusterL(TInt aDirCluster);
1.123 + void CheckDirStructureL();
1.124 + void CheckDirL(TUint32 aCluster);
1.125 + void ProcessEntryL(const TFatDirEntry& aEntry);
1.126 + TInt CheckEntryClusterL(const TFatDirEntry& aEntry, const TEntryPos& aEntryPos);
1.127 + void RecordClusterChainL(TInt aCluster,TUint aSizeInBytes);
1.128 + TBool MoveToVFatEndL(TEntryPos& aPos,TFatDirEntry& aEntry,TInt& aDirLength);
1.129 + TBool IsValidVFatEntry(const TFatDirEntry& aEntry,TInt prevNum)const;
1.130 + TBool IsDosEntry(const TFatDirEntry& aEntry)const;
1.131 + void AddPartialVFatL(const TEntryPos& aStartPos, const TFatDirEntry& aEntry);
1.132 + TBool AddMatchingEntryL(const TEntryPos& aEntryPos);
1.133 + TInt GetReservedidL(const TEntryPos aVFatPos);
1.134 +
1.135 + void FixPartEntryL();
1.136 + void FixMatchingEntryL();
1.137 + void MovePastEntriesL(TEntryPos& aEntryPos,TFatDirEntry& aEntry,TInt aToMove,TInt& aDirEntries);
1.138 + void AddToClusterListL(TInt aCluster);
1.139 + inline TBool AlreadyExistsL(TInt aCluster)const;
1.140 + inline TBool IsEndOfRootDir(const TEntryPos& aPos)const;
1.141 + inline TBool IsEofF(TInt aVal)const;
1.142 + inline TBool IsDirError()const;
1.143 + void MoveToNextEntryL(TEntryPos& aPos);
1.144 + void ReadDirEntryL(const TEntryPos& aPos,TFatDirEntry& aDirEntry);
1.145 +
1.146 + inline void IndicateErrorsFound(TGenericError aError);
1.147 + inline TUint32 MaxClusters() const;
1.148 + inline TBool CheckDiskMode() const;
1.149 +
1.150 +protected:
1.151 +
1.152 + /**
1.153 + Internal ScanDrive mode specific errors. In Rugged FAT mode (current implementatio) any type of error of this kind can occur only once and it will be fixed.
1.154 + Othersise the FS is considered to be corrupted
1.155 + */
1.156 + enum TDirError
1.157 + {
1.158 + ENoDirError= 0, ///< no errors found
1.159 + EScanMatchingEntry=1, ///< Two entries pointing to the same cluster chain; Rugged FAT rename/replace artefact
1.160 + EScanPartEntry, ///< Deleted DOS entry and orphaned VFAT ones from the same entryset; Rugged FAT 'file/dir delete' artefact
1.161 + };
1.162 +
1.163 +
1.164 +private:
1.165 + CFatMountCB* iMount; ///< The owning Fat mount
1.166 +
1.167 + TPartVFatEntry iPartEntry; ///< Storage for a partial VFat entry set error, see EScanPartEntry
1.168 + TMatchingStartCluster iMatching; ///< Storage for Matching start cluster error, see EScanMatchingEntry
1.169 +
1.170 + TDirError iDirError; ///< Indicates the error tpye found also used to indicate if an error has occured
1.171 + TInt iDirsChecked; ///< Count of the number of directories checked
1.172 + TInt iRecursiveDepth; ///< Depth of recursion the scan has reached
1.173 + RArray<TInt>* iClusterListArray[KMaxArrayDepth]; ///< Size in bytes of the bit packed Fat Cluster list array used when maximum depth has been reached so that directory may be re-visited. Avoid stack overflow
1.174 +
1.175 + TUint iListArrayIndex; ///< Current position into cluster list array
1.176 + TUint32 iTruncationCluster; ///< Cluster at which cluster chain truncation should take place, used for truncation errors
1.177 + TUint32 iMaxClusters; ///< Max. amount of clusters on the volume
1.178 +
1.179 + RBitVector iMediaFatBits; ///< Storage for bit packed Fat read from media
1.180 + RBitVector iScanFatBits; ///< Storage for bit packed Fat built up by the scan
1.181 +
1.182 + TGenericError iGenericError; ///< FS error that is discovered by scanning in any mode
1.183 + TScanDriveMode iScanDriveMode; ///< mode of operation
1.184 + };
1.185 +
1.186 +
1.187 +
1.188 +#endif //SL_SCANDRV_H
1.189 +
1.190 +