/* * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This Original Code and all software distributed under the License are * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* File: FileExtentMapping.c Contains: xxx put contents here xxx Version: HFS Plus 1.0 Written by: Dave Heller, Mark Day Copyright: © 1996-1999 by Apple Computer, Inc., all rights reserved. File Ownership: DRI: Mark Day Other Contact: xxx put other contact here xxx Technology: xxx put technology here xxx Writers: (DSH) Deric Horn (msd) Mark Day (djb) Don Brady Change History (most recent first): <MacOSX> 9/9/99 djb Fix fcbModifiedMask flag testing logic. <MacOSX> 8/25/98 djb Flush extents b-tree header if dirty (2371088). <MacOSX> 6/30/98 djb Add functions NodesAreContiguous and ExtentsAreIntegral (for radar #2249539). <MacOSX> 6/23/98 djb Changed DeallocFile to DeleteFile which now deletes the catalog record. Fixed UpdateExtentRecord to pass correct fcb to Btree routines. Fixed hfs+ bug in CreateExtentRecord (double dereference). <MacOSX> 5/20/98 djb In ExtendFileC don't lie about the peof! (radar #2230094). <MacOSX> 4/17/98 djb Add VCB locking. <MacOSX> 4/2/98 djb Switch over to real BTree interface (no more BTreeWrapper.c). <MacOSX> 3/31/98 djb Sync up with final HFSVolumes.h header file. <CS24> 1/23/98 msd Bug 2208024: AllocContig is actually allocating one extent even though there is not enough contiguous space. <CS23> 12/2/97 DSH GetFCBExtentRecord no longer static so DFA can use it. <CS22> 10/20/97 msd When allocating more space for a file, do the clump size calculations in ExtendFileC, not BlockAllocate. Undo change from <CS18>. <CS21> 10/17/97 msd Conditionalize DebugStrs. <CS20> 10/16/97 msd Simplify the code path for MapFileBlockC (logical to physical block mapping) in the typical case where the file isn't fragmented so badly that it has extents in the extents B-tree. Simplified some of the calculations for all cases. <CS19> 10/13/97 DSH FindExtentRecord & DeleteExtentRecord are also being used by DFA no longer static. <CS18> 10/6/97 msd When extending a file, set the physical EOF to include any extra space allocated due to a file's clump size. <CS17> 9/19/97 msd Remove the MapLogicalToPhysical SPI. It was never used and is not being tested anyway. <CS16> 9/5/97 msd In CompareExtentKeys and CompareExtentKeysPlus, use the symbolic constants for key length. Don't DebugStr unless DEBUG_BUILD is set. <CS15> 7/24/97 djb Add instrumentation to MapFileBlockC <CS14> 7/16/97 DSH FilesInternal.i renamed FileMgrInternal.i to avoid name collision <CS13> 7/15/97 DSH AdjEOF() mark the FCB as modified. (1664389) <CS12> 7/8/97 DSH Loading PrecompiledHeaders from define passed in on C line <CS11> 7/3/97 msd Bug #1663518. Remove DebugStr when setting the FCB extent record for a volume control file. <CS10> 6/27/97 msd Moved enum kFirstFileRefnum to FilesInternal. <CS9> 6/24/97 djb Include "CatalogPrivate.h" <CS8> 6/16/97 msd Finish implementation of CreateLargeFile SPI. <CS7> 6/12/97 msd Add stub for CreateLargeFile SPI. <CS6> 6/5/97 msd Add MapLogicalToPhysical. <CS5> 6/2/97 msd In TruncateFileC, don't update the extent record unless it was actually changed (prevents extra updates when truncating to the end of the extent, and it is the last extent of the file.) Added an AdjustEOF routine called by the assembly AdjEOF routine. It copies the EOF, physical length, and extent information from one FCB to all other FCBs for that fork. <CS4> 5/20/97 DSH Removed const declaration in MapFileBlocC, const is benign when passing by value, and SC requires it to match prototype. <CS3> 5/15/97 msd Change enum kResourceForkType from -1 to 0xFF since it is now unsigned. Change all forkType parameters to UInt8. <CS2> 5/7/97 msd When checking for an unused extent descriptor, check the length, not the starting block. <CS1> 4/24/97 djb first checked in <HFS25> 4/11/97 DSH use extended VCB fields catalogRefNum, and extentsRefNum. <HFS24> 4/4/97 djb Get in sync with volume format changes. <HFS23> 3/17/97 DSH Casting to compile with SC. <HFS22> 2/26/97 msd Add instrumentation in ExtendFileC and TruncateFileC. In CompareExtentKeys and CompareExtentKeysPlus, make sure the key lengths are correct. <HFS21> 2/5/97 msd The comparison with fsBTStartOfIterationErr didn't work because the enum is an unsigned long; it is now casted to an OSErr before comparing. <HFS20> 1/31/97 msd In FindExtentRecord, turn an fsBTStartOfIterationErr error into btNotFound. <HFS19> 1/28/97 msd Fixed bug in MapFileBlockC where it returned the wrong number of bytes available at the given block number. This could potentially cause programs to read or write over other files. <HFS18> 1/16/97 djb Extent key compare procs now return SInt32. Fixed UpdateExtentRecord - it was passing a pointer to an ExtentKey pointer. <HFS17> 1/10/97 msd Change TruncateFileC to call DellocateFork when the new PEOF is 0. Fixes a fxRangeErr returned when no extents existed. <HFS16> 1/6/97 msd Previous change prevents extent records from being removed if the files new PEOF is in the local (FCB/catalog) extents. <HFS15> 1/3/97 djb Temp fix in TruncateFileC to prevent unwanted calls to TruncateExtents. <HFS14> 12/23/96 msd Previous change to SearchExtentFile didn't set up the outputs for hint and key when the FCB extent record wasn't full. <HFS13> 12/20/96 msd In SearchExtentFile, don't bother searching the extents file if the FCB's extent record wasn't full, or if the FCB was for the extents file itself. Modified SearchExtentRecord to return a Boolean to indicate that the record was not full. <HFS12> 12/19/96 DSH Changed refs from VCB to ExtendedVCB <HFS11> 12/19/96 djb Updated for new B-tree Manager interface. <HFS10> 12/12/96 djb Really use new SPI for GetCatalogNode. <HFS9> 12/12/96 djb Use new Catalog SPI for GetCatalogNode. Added Mark's changes to MapFileBlockC. <HFS8> 12/11/96 msd TruncateFileC must always release extents, even if PEOF hasn't changed (since allocation may have been rounded up due to clump size). <HFS7> 12/10/96 msd Check PRAGMA_LOAD_SUPPORTED before loading precompiled headers. <HFS6> 12/4/96 DSH Precompiled headers <HFS5> 11/26/96 msd Add an exported routine to grow the parallel FCB table to accomodate the HFS+ ExtentRecord. <HFS4> 11/26/96 msd Convert internal routines to use ExtentKey and ExtentRecord (instead of the raw HFS structures). <HFS3> 11/21/96 msd Added CompareExtentKeysPlus(). <HFS2> 11/20/96 msd Finish porting FXM to C. <HFS1> 11/6/96 DKH first checked in */ #include "../../hfs.h" #include "../../hfs_format.h" #include "../../hfs_endian.h" #include "../headers/FileMgrInternal.h" #include "../headers/BTreesInternal.h" #include "../headers/CatalogPrivate.h" // calling a private catalog routine (LocateCatalogNode) #include <sys/malloc.h> /* ============================================================ Public (Exported) Routines: ============================================================ DeAllocFile Deallocate all disk space allocated to a specified file. Both forks are deallocated. ExtendFileC Allocate more space to a given file. CompareExtentKeys Compare two extents file keys (a search key and a trial key). Used by the BTree manager when searching for, adding, or deleting keys in the extents file of an HFS volume. CompareExtentKeysPlus Compare two extents file keys (a search key and a trial key). Used by the BTree manager when searching for, adding, or deleting keys in the extents file of an HFS+ volume. MapFileBlockC Convert (map) an offset within a given file into a physical disk address. TruncateFileC Truncates the disk space allocated to a file. The file space is truncated to a specified new physical EOF, rounded up to the next allocation block boundry. There is an option to truncate to the end of the extent containing the new EOF. FlushExtentFile Flush the extents file for a given volume. GrowParallelFCBs Make sure the parallel FCB entries are big enough to support the HFS+ ExtentRecord. If not, the array is grown and the pre-existing data copied over. AdjustEOF Copy EOF, physical length, and extent records from one FCB to all other FCBs for that fork. This is used when a file is grown or shrunk as the result of a Write, SetEOF, or Allocate. MapLogicalToPhysical Map some position in a file to a volume block number. Also returns the number of contiguous bytes that are mapped there. This is a queued HFSDispatch call that does the equivalent of MapFileBlockC, using a parameter block. ============================================================ Internal Routines: ============================================================ FindExtentRecord Search the extents BTree for a particular extent record. SearchExtentFile Search the FCB and extents file for an extent record that contains a given file position (in bytes). SearchExtentRecord Search a given extent record to see if it contains a given file position (in bytes). Used by SearchExtentFile. ReleaseExtents Deallocate all allocation blocks in all extents of an extent data record. TruncateExtents Deallocate blocks and delete extent records for all allocation blocks beyond a certain point in a file. The starting point must be the first file allocation block for some extent record for the file. DeallocateFork Deallocate all allocation blocks belonging to a given fork. UpdateExtentRecord If the extent record came from the extents file, write out the updated record; otherwise, copy the updated record into the FCB resident extent record. If the record has no extents, and was in the extents file, then delete the record instead. */ static const SInt64 kTwoGigabytes = 0x80000000LL; enum { kDataForkType = 0, kResourceForkType = 0xFF, kPreviousRecord = -1 }; void HFSToHFSPlusExtents( const HFSExtentRecord oldExtents, HFSPlusExtentRecord newExtents); OSErr HFSPlusToHFSExtents( const HFSPlusExtentRecord oldExtents, HFSExtentRecord newExtents); OSErr FindExtentRecord( const ExtendedVCB *vcb, UInt8 forkType, UInt32 fileID, UInt32 startBlock, Boolean allowPrevious, HFSPlusExtentKey *foundKey, HFSPlusExtentRecord foundData, UInt32 *foundHint); OSErr DeleteExtentRecord( const ExtendedVCB *vcb, UInt8 forkType, UInt32 fileID, UInt32 startBlock); static OSErr CreateExtentRecord( const ExtendedVCB *vcb, HFSPlusExtentKey *key, HFSPlusExtentRecord extents, UInt32 *hint); OSErr GetFCBExtentRecord( const FCB *fcb, HFSPlusExtentRecord extents); static OSErr SearchExtentFile( const ExtendedVCB *vcb, const FCB *fcb, SInt64 filePosition, HFSPlusExtentKey *foundExtentKey, HFSPlusExtentRecord foundExtentData, UInt32 *foundExtentDataIndex, UInt32 *extentBTreeHint, UInt32 *endingFABNPlusOne ); static OSErr SearchExtentRecord( const ExtendedVCB *vcb, UInt32 searchFABN, const HFSPlusExtentRecord extentData, UInt32 extentDataStartFABN, UInt32 *foundExtentDataOffset, UInt32 *endingFABNPlusOne, Boolean *noMoreExtents); static OSErr ReleaseExtents( ExtendedVCB *vcb, const HFSPlusExtentRecord extentRecord, UInt32 *numReleasedAllocationBlocks, Boolean *releasedLastExtent); static OSErr DeallocateFork( ExtendedVCB *vcb, HFSCatalogNodeID fileID, UInt8 forkType, HFSPlusExtentRecord catalogExtents, Boolean * recordDeleted); static OSErr TruncateExtents( ExtendedVCB *vcb, UInt8 forkType, UInt32 fileID, UInt32 startBlock, Boolean * recordDeleted); static OSErr UpdateExtentRecord ( const ExtendedVCB *vcb, FCB *fcb, const HFSPlusExtentKey *extentFileKey, const HFSPlusExtentRecord extentData, UInt32 extentBTreeHint); static Boolean ExtentsAreIntegral( const HFSPlusExtentRecord extentRecord, UInt32 mask, UInt32 *blocksChecked, Boolean *checkedLastExtent); //_________________________________________________________________________________ // // Routine: FindExtentRecord // // Purpose: Search the extents BTree for an extent record matching the given // FileID, fork, and starting file allocation block number. // // Inputs: // vcb Volume to search // forkType 0 = data fork, -1 = resource fork // fileID File's FileID (CatalogNodeID) // startBlock Starting file allocation block number // allowPrevious If the desired record isn't found and this flag is set, // then see if the previous record belongs to the same fork. // If so, then return it. // // Outputs: // foundKey The key data for the record actually found // foundData The extent record actually found (NOTE: on an HFS volume, the // fourth entry will be zeroes. // foundHint The BTree hint to find the node again //_________________________________________________________________________________ OSErr FindExtentRecord( const ExtendedVCB *vcb, UInt8 forkType, UInt32 fileID, UInt32 startBlock, Boolean allowPrevious, HFSPlusExtentKey *foundKey, HFSPlusExtentRecord foundData, UInt32 *foundHint) { FCB * fcb; BTreeIterator *btIterator; FSBufferDescriptor btRecord; OSErr err; UInt16 btRecordSize; err = noErr; *foundHint = 0; fcb = GetFileControlBlock(vcb->extentsRefNum); MALLOC(btIterator, BTreeIterator *, sizeof(*btIterator), M_TEMP, M_WAITOK); bzero(btIterator, sizeof(*btIterator)); if (vcb->vcbSigWord == kHFSSigWord) { HFSExtentKey * extentKeyPtr; HFSExtentRecord extentData; extentKeyPtr = (HFSExtentKey*) &btIterator->key; extentKeyPtr->keyLength = kHFSExtentKeyMaximumLength; extentKeyPtr->forkType = forkType; extentKeyPtr->fileID = fileID; extentKeyPtr->startBlock = startBlock; btRecord.bufferAddress = &extentData; btRecord.itemSize = sizeof(HFSExtentRecord); btRecord.itemCount = 1; err = BTSearchRecord(fcb, btIterator, &btRecord, &btRecordSize, btIterator); if (err == btNotFound && allowPrevious) { err = BTIterateRecord(fcb, kBTreePrevRecord, btIterator, &btRecord, &btRecordSize); // A previous record may not exist, so just return btNotFound (like we would if // it was for the wrong file/fork). if (err == (OSErr) fsBTStartOfIterationErr) //¥¥ fsBTStartOfIterationErr is type unsigned long err = btNotFound; if (err == noErr) { // Found a previous record. Does it belong to the same fork of the same file? if (extentKeyPtr->fileID != fileID || extentKeyPtr->forkType != forkType) err = btNotFound; } } if (err == noErr) { UInt16 i; // Copy the found key back for the caller foundKey->keyLength = kHFSPlusExtentKeyMaximumLength; foundKey->forkType = extentKeyPtr->forkType; foundKey->pad = 0; foundKey->fileID = extentKeyPtr->fileID; foundKey->startBlock = extentKeyPtr->startBlock; // Copy the found data back for the caller foundData[0].startBlock = extentData[0].startBlock; foundData[0].blockCount = extentData[0].blockCount; foundData[1].startBlock = extentData[1].startBlock; foundData[1].blockCount = extentData[1].blockCount; foundData[2].startBlock = extentData[2].startBlock; foundData[2].blockCount = extentData[2].blockCount; for (i = 3; i < kHFSPlusExtentDensity; ++i) { foundData[i].startBlock = 0; foundData[i].blockCount = 0; } } } else { // HFS Plus volume HFSPlusExtentKey * extentKeyPtr; HFSPlusExtentRecord extentData; extentKeyPtr = (HFSPlusExtentKey*) &btIterator->key; extentKeyPtr->keyLength = kHFSPlusExtentKeyMaximumLength; extentKeyPtr->forkType = forkType; extentKeyPtr->pad = 0; extentKeyPtr->fileID = fileID; extentKeyPtr->startBlock = startBlock; btRecord.bufferAddress = &extentData; btRecord.itemSize = sizeof(HFSPlusExtentRecord); btRecord.itemCount = 1; err = BTSearchRecord(fcb, btIterator, &btRecord, &btRecordSize, btIterator); if (err == btNotFound && allowPrevious) { err = BTIterateRecord(fcb, kBTreePrevRecord, btIterator, &btRecord, &btRecordSize); // A previous record may not exist, so just return btNotFound (like we would if // it was for the wrong file/fork). if (err == (OSErr) fsBTStartOfIterationErr) //¥¥ fsBTStartOfIterationErr is type unsigned long err = btNotFound; if (err == noErr) { // Found a previous record. Does it belong to the same fork of the same file? if (extentKeyPtr->fileID != fileID || extentKeyPtr->forkType != forkType) err = btNotFound; } } if (err == noErr) { // Copy the found key back for the caller BlockMoveData(extentKeyPtr, foundKey, sizeof(HFSPlusExtentKey)); // Copy the found data back for the caller BlockMoveData(&extentData, foundData, sizeof(HFSPlusExtentRecord)); } } *foundHint = btIterator->hint.nodeNum; FREE(btIterator, M_TEMP); return err; } static OSErr CreateExtentRecord( const ExtendedVCB *vcb, HFSPlusExtentKey *key, HFSPlusExtentRecord extents, UInt32 *hint) { BTreeIterator * btIterator; FSBufferDescriptor btRecord; UInt16 btRecordSize; OSErr err; err = noErr; *hint = 0; // XXXdbg - preflight that there's enough space err = BTCheckFreeSpace(GetFileControlBlock(vcb->extentsRefNum)); if (err) return err; MALLOC(btIterator, BTreeIterator *, sizeof(*btIterator), M_TEMP, M_WAITOK); bzero(btIterator, sizeof(*btIterator)); if (vcb->vcbSigWord == kHFSSigWord) { HFSExtentKey * keyPtr; HFSExtentRecord data; btRecordSize = sizeof(HFSExtentRecord); btRecord.bufferAddress = &data; btRecord.itemSize = btRecordSize; btRecord.itemCount = 1; keyPtr = (HFSExtentKey*) &btIterator->key; keyPtr->keyLength = kHFSExtentKeyMaximumLength; keyPtr->forkType = key->forkType; keyPtr->fileID = key->fileID; keyPtr->startBlock = key->startBlock; err = HFSPlusToHFSExtents(extents, data); } else { // HFS Plus volume btRecordSize = sizeof(HFSPlusExtentRecord); btRecord.bufferAddress = extents; btRecord.itemSize = btRecordSize; btRecord.itemCount = 1; BlockMoveData(key, &btIterator->key, sizeof(HFSPlusExtentKey)); } if (err == noErr) err = BTInsertRecord(GetFileControlBlock(vcb->extentsRefNum), btIterator, &btRecord, btRecordSize); if (err == noErr) *hint = btIterator->hint.nodeNum; (void) BTFlushPath(GetFileControlBlock(vcb->extentsRefNum)); FREE(btIterator, M_TEMP); return err; } OSErr DeleteExtentRecord( const ExtendedVCB *vcb, UInt8 forkType, UInt32 fileID, UInt32 startBlock) { BTreeIterator * btIterator; OSErr err; err = noErr; // XXXdbg - preflight that there's enough space err = BTCheckFreeSpace(GetFileControlBlock(vcb->extentsRefNum)); if (err) return err; MALLOC(btIterator, BTreeIterator *, sizeof(*btIterator), M_TEMP, M_WAITOK); bzero(btIterator, sizeof(*btIterator)); if (vcb->vcbSigWord == kHFSSigWord) { HFSExtentKey * keyPtr; keyPtr = (HFSExtentKey*) &btIterator->key; keyPtr->keyLength = kHFSExtentKeyMaximumLength; keyPtr->forkType = forkType; keyPtr->fileID = fileID; keyPtr->startBlock = startBlock; } else { // HFS Plus volume HFSPlusExtentKey * keyPtr; keyPtr = (HFSPlusExtentKey*) &btIterator->key; keyPtr->keyLength = kHFSPlusExtentKeyMaximumLength; keyPtr->forkType = forkType; keyPtr->pad = 0; keyPtr->fileID = fileID; keyPtr->startBlock = startBlock; } err = BTDeleteRecord(GetFileControlBlock(vcb->extentsRefNum), btIterator); (void) BTFlushPath(GetFileControlBlock(vcb->extentsRefNum)); FREE(btIterator, M_TEMP); return err; } //_________________________________________________________________________________ // // Routine: MapFileBlock // // Function: Maps a file position into a physical disk address. // // Input: A2.L - VCB pointer // (A1,D1.W) - FCB pointer // D4.L - number of bytes desired // D5.L - file position (byte address) // // Output: D3.L - physical start block // D6.L - number of contiguous bytes available (up to D4 bytes) // D0.L - result code <01Oct85> // 0 = ok // FXRangeErr = file position beyond mapped range <17Oct85> // FXOvFlErr = extents file overflow <17Oct85> // other = error <17Oct85> // // Called By: Log2Phys (read/write in place), Cache (map a file block). //_________________________________________________________________________________ OSErr MapFileBlockC ( ExtendedVCB *vcb, // volume that file resides on FCB *fcb, // FCB of file size_t numberOfBytes, // number of contiguous bytes desired off_t offset, // starting offset within file (in bytes) daddr_t *startSector, // first sector (NOT an allocation block) size_t *availableBytes) // number of contiguous bytes (up to numberOfBytes) { OSErr err; UInt32 allocBlockSize; // Size of the volume's allocation block UInt32 sectorSize; HFSPlusExtentKey foundKey; HFSPlusExtentRecord foundData; UInt32 foundIndex; UInt32 hint; UInt32 firstFABN; // file allocation block of first block in found extent UInt32 nextFABN; // file allocation block of block after end of found extent off_t dataEnd; // (offset) end of range that is contiguous UInt32 sectorsPerBlock; // Number of sectors per allocation block UInt32 startBlock; // volume allocation block corresponding to firstFABN daddr_t temp; off_t tmpOff; allocBlockSize = vcb->blockSize; sectorSize = VCBTOHFS(vcb)->hfs_phys_block_size; err = SearchExtentFile(vcb, fcb, offset, &foundKey, foundData, &foundIndex, &hint, &nextFABN); if (err == noErr) { startBlock = foundData[foundIndex].startBlock; firstFABN = nextFABN - foundData[foundIndex].blockCount; } if (err != noErr) { return err; } // // Determine the end of the available space. It will either be the end of the extent, // or the file's PEOF, whichever is smaller. // dataEnd = (off_t)((off_t)(nextFABN) * (off_t)(allocBlockSize)); // Assume valid data through end of this extent if (((off_t)fcb->ff_blocks * (off_t)allocBlockSize) < dataEnd) // Is PEOF shorter? dataEnd = (off_t)fcb->ff_blocks * (off_t)allocBlockSize; // Yes, so only map up to PEOF // Compute the number of sectors in an allocation block sectorsPerBlock = allocBlockSize / sectorSize; // sectors per allocation block // // Compute the absolute sector number that contains the offset of the given file // offset in sectors from start of the extent + // offset in sectors from start of allocation block space // temp = (daddr_t)((offset - (off_t)((off_t)(firstFABN) * (off_t)(allocBlockSize)))/sectorSize); temp += startBlock * sectorsPerBlock; /* Add in any volume offsets */ if (vcb->vcbSigWord == kHFSPlusSigWord) temp += vcb->hfsPlusIOPosOffset / sectorSize; else temp += vcb->vcbAlBlSt; // Return the desired sector for file position "offset" *startSector = temp; // // Determine the number of contiguous bytes until the end of the extent // (or the amount they asked for, whichever comes first). // tmpOff = dataEnd - offset; if (tmpOff > (off_t)(numberOfBytes)) *availableBytes = numberOfBytes; // more there than they asked for, so pin the output else *availableBytes = tmpOff; return noErr; } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: ReleaseExtents // // Function: Release the extents of a single extent data record. //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ static OSErr ReleaseExtents( ExtendedVCB *vcb, const HFSPlusExtentRecord extentRecord, UInt32 *numReleasedAllocationBlocks, Boolean *releasedLastExtent) { UInt32 extentIndex; UInt32 numberOfExtents; OSErr err = noErr; *numReleasedAllocationBlocks = 0; *releasedLastExtent = false; if (vcb->vcbSigWord == kHFSPlusSigWord) numberOfExtents = kHFSPlusExtentDensity; else numberOfExtents = kHFSExtentDensity; for( extentIndex = 0; extentIndex < numberOfExtents; extentIndex++) { UInt32 numAllocationBlocks; // Loop over the extent record and release the blocks associated with each extent. numAllocationBlocks = extentRecord[extentIndex].blockCount; if ( numAllocationBlocks == 0 ) { *releasedLastExtent = true; break; } err = BlockDeallocate( vcb, extentRecord[extentIndex].startBlock, numAllocationBlocks ); if ( err != noErr ) break; *numReleasedAllocationBlocks += numAllocationBlocks; // bump FABN to beg of next extent } return( err ); } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: TruncateExtents // // Purpose: Delete extent records whose starting file allocation block number // is greater than or equal to a given starting block number. The // allocation blocks represented by the extents are deallocated. // // Inputs: // vcb Volume to operate on // fileID Which file to operate on // startBlock Starting file allocation block number for first extent // record to delete. //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ static OSErr TruncateExtents( ExtendedVCB *vcb, UInt8 forkType, UInt32 fileID, UInt32 startBlock, Boolean * recordDeleted) { OSErr err; UInt32 numberExtentsReleased; Boolean releasedLastExtent; UInt32 hint; HFSPlusExtentKey key; HFSPlusExtentRecord extents; while (true) { err = FindExtentRecord(vcb, forkType, fileID, startBlock, false, &key, extents, &hint); if (err != noErr) { if (err == btNotFound) err = noErr; break; } err = ReleaseExtents( vcb, extents, &numberExtentsReleased, &releasedLastExtent ); if (err != noErr) break; err = DeleteExtentRecord(vcb, forkType, fileID, startBlock); if (err != noErr) break; *recordDeleted = true; startBlock += numberExtentsReleased; } return err; } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: DeallocateFork // // Function: De-allocates all disk space allocated to a specified fork. //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ static OSErr DeallocateFork( ExtendedVCB *vcb, HFSCatalogNodeID fileID, UInt8 forkType, HFSPlusExtentRecord catalogExtents, Boolean * recordDeleted) /* true if a record was deleted */ { OSErr err; UInt32 numReleasedAllocationBlocks; Boolean releasedLastExtent; // Release the catalog extents err = ReleaseExtents( vcb, catalogExtents, &numReleasedAllocationBlocks, &releasedLastExtent ); // Release the extra extents, if present if (err == noErr && !releasedLastExtent) err = TruncateExtents(vcb, forkType, fileID, numReleasedAllocationBlocks, recordDeleted); return( err ); } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: FlushExtentFile // // Function: Flushes the extent file for a specified volume //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ OSErr FlushExtentFile( ExtendedVCB *vcb ) { FCB * fcb; OSErr err; fcb = GetFileControlBlock(vcb->extentsRefNum); err = BTFlushPath(fcb); if ( err == noErr ) { // If the FCB for the extent "file" is dirty, mark the VCB as dirty. if (FTOC(fcb)->c_flag & C_MODIFIED) { MarkVCBDirty( vcb ); // err = FlushVolumeControlBlock( vcb ); } } return( err ); } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: CompareExtentKeys // // Function: Compares two extent file keys (a search key and a trial key) for // an HFS volume. //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ SInt32 CompareExtentKeys( const HFSExtentKey *searchKey, const HFSExtentKey *trialKey ) { SInt32 result; // ± 1 #if DEBUG_BUILD if (searchKey->keyLength != kHFSExtentKeyMaximumLength) DebugStr("\pHFS: search Key is wrong length"); if (trialKey->keyLength != kHFSExtentKeyMaximumLength) DebugStr("\pHFS: trial Key is wrong length"); #endif result = -1; // assume searchKey < trialKey if (searchKey->fileID == trialKey->fileID) { // // FileNum's are equal; compare fork types // if (searchKey->forkType == trialKey->forkType) { // // Fork types are equal; compare allocation block number // if (searchKey->startBlock == trialKey->startBlock) { // // Everything is equal // result = 0; } else { // // Allocation block numbers differ; determine sign // if (searchKey->startBlock > trialKey->startBlock) result = 1; } } else { // // Fork types differ; determine sign // if (searchKey->forkType > trialKey->forkType) result = 1; } } else { // // FileNums differ; determine sign // if (searchKey->fileID > trialKey->fileID) result = 1; } return( result ); } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: CompareExtentKeysPlus // // Function: Compares two extent file keys (a search key and a trial key) for // an HFS volume. //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ SInt32 CompareExtentKeysPlus( const HFSPlusExtentKey *searchKey, const HFSPlusExtentKey *trialKey ) { SInt32 result; // ± 1 #if DEBUG_BUILD if (searchKey->keyLength != kHFSPlusExtentKeyMaximumLength) DebugStr("\pHFS: search Key is wrong length"); if (trialKey->keyLength != kHFSPlusExtentKeyMaximumLength) DebugStr("\pHFS: trial Key is wrong length"); #endif result = -1; // assume searchKey < trialKey if (searchKey->fileID == trialKey->fileID) { // // FileNum's are equal; compare fork types // if (searchKey->forkType == trialKey->forkType) { // // Fork types are equal; compare allocation block number // if (searchKey->startBlock == trialKey->startBlock) { // // Everything is equal // result = 0; } else { // // Allocation block numbers differ; determine sign // if (searchKey->startBlock > trialKey->startBlock) result = 1; } } else { // // Fork types differ; determine sign // if (searchKey->forkType > trialKey->forkType) result = 1; } } else { // // FileNums differ; determine sign // if (searchKey->fileID > trialKey->fileID) result = 1; } return( result ); } //_________________________________________________________________________________ // // Routine: Extendfile // // Function: Extends the disk space allocated to a file. // // Input: A2.L - VCB pointer // A1.L - pointer to FCB array // D1.W - file refnum // D3.B - option flags // kEFContigMask - force contiguous allocation // kEFAllMask - allocate all requested bytes or none // NOTE: You may not set both options. // D4.L - number of additional bytes to allocate // // Output: D0.W - result code // 0 = ok // -n = IO error // D6.L - number of bytes allocated // // Called by: FileAloc,FileWrite,SetEof // // Note: ExtendFile updates the PEOF in the FCB. //_________________________________________________________________________________ OSErr ExtendFileC ( ExtendedVCB *vcb, // volume that file resides on FCB *fcb, // FCB of file to truncate SInt64 bytesToAdd, // number of bytes to allocate UInt32 blockHint, // desired starting allocation block UInt32 flags, // EFContig and/or EFAll SInt64 *actualBytesAdded) // number of bytes actually allocated { OSErr err; UInt32 volumeBlockSize; SInt64 blocksToAdd; SInt64 bytesThisExtent; HFSPlusExtentKey foundKey; HFSPlusExtentRecord foundData; UInt32 foundIndex; UInt32 hint; UInt32 nextBlock; UInt32 startBlock; Boolean allOrNothing; Boolean forceContig; Boolean wantContig; Boolean needsFlush; UInt32 actualStartBlock; UInt32 actualNumBlocks; UInt32 numExtentsPerRecord; SInt64 maximumBytes; SInt64 peof; UInt32 prevblocks; needsFlush = false; *actualBytesAdded = 0; volumeBlockSize = vcb->blockSize; allOrNothing = ((flags & kEFAllMask) != 0); forceContig = ((flags & kEFContigMask) != 0); prevblocks = fcb->ff_blocks; if (vcb->vcbSigWord == kHFSPlusSigWord) numExtentsPerRecord = kHFSPlusExtentDensity; else numExtentsPerRecord = kHFSExtentDensity; // // Make sure the request and new PEOF are less than 2GB if HFS. // if (vcb->vcbSigWord == kHFSSigWord) { if (bytesToAdd >= kTwoGigabytes) goto Overflow; if ((((SInt64)fcb->ff_blocks * (SInt64)volumeBlockSize) + bytesToAdd) >= kTwoGigabytes) goto Overflow; } // // Determine how many blocks need to be allocated. // Round up the number of desired bytes to add. // blocksToAdd = FileBytesToBlocks(bytesToAdd, volumeBlockSize); bytesToAdd = (SInt64)((SInt64)blocksToAdd * (SInt64)volumeBlockSize); /* * For deferred allocations just reserve the blocks. */ if ((flags & kEFDeferMask) && (vcb->vcbSigWord == kHFSPlusSigWord) && (bytesToAdd < (SInt64)HFS_MAX_DEFERED_ALLOC) && (blocksToAdd < hfs_freeblks(VCBTOHFS(vcb), 1))) { fcb->ff_unallocblocks += blocksToAdd; vcb->loanedBlocks += blocksToAdd; FTOC(fcb)->c_blocks += blocksToAdd; fcb->ff_blocks += blocksToAdd; FTOC(fcb)->c_flag |= C_MODIFIED; *actualBytesAdded = bytesToAdd; return (0); } /* * Give back any unallocated blocks before doing real allocations. */ if (fcb->ff_unallocblocks > 0) { blocksToAdd += fcb->ff_unallocblocks; bytesToAdd = (SInt64)blocksToAdd * (SInt64)volumeBlockSize; vcb->loanedBlocks -= fcb->ff_unallocblocks; FTOC(fcb)->c_blocks -= fcb->ff_unallocblocks; fcb->ff_blocks -= fcb->ff_unallocblocks; fcb->ff_unallocblocks = 0; } // // If the file's clump size is larger than the allocation block size, // then set the maximum number of bytes to the requested number of bytes // rounded up to a multiple of the clump size. // if ((fcb->fcbClmpSize > volumeBlockSize) && (bytesToAdd < (SInt64)HFS_MAX_DEFERED_ALLOC) && (flags & kEFNoClumpMask) == 0) { maximumBytes = (SInt64)FileBytesToBlocks(bytesToAdd, fcb->fcbClmpSize); maximumBytes *= fcb->fcbClmpSize; } else { maximumBytes = bytesToAdd; } // // Compute new physical EOF, rounded up to a multiple of a block. // if ((vcb->vcbSigWord == kHFSSigWord) && ((((SInt64)fcb->ff_blocks * (SInt64)volumeBlockSize) + bytesToAdd) >= kTwoGigabytes)) // Too big? if (allOrNothing) // Yes, must they have it all? goto Overflow; // Yes, can't have it else { --blocksToAdd; // No, give give 'em one block less bytesToAdd -= volumeBlockSize; } // // If allocation is all-or-nothing, make sure there are // enough free blocks on the volume (quick test). // if (allOrNothing && (blocksToAdd > hfs_freeblks(VCBTOHFS(vcb), flags & kEFReserveMask))) { err = dskFulErr; goto ErrorExit; } // // See if there are already enough blocks allocated to the file. // peof = ((SInt64)fcb->ff_blocks * (SInt64)volumeBlockSize) + bytesToAdd; // potential new PEOF err = SearchExtentFile(vcb, fcb, peof-1, &foundKey, foundData, &foundIndex, &hint, &nextBlock); if (err == noErr) { // Enough blocks are already allocated. Just update the FCB to reflect the new length. fcb->ff_blocks = peof / volumeBlockSize; FTOC(fcb)->c_blocks += (bytesToAdd / volumeBlockSize); FTOC(fcb)->c_flag |= C_MODIFIED; goto Exit; } if (err != fxRangeErr) // Any real error? goto ErrorExit; // Yes, so exit immediately // // Adjust the PEOF to the end of the last extent. // peof = (SInt64)((SInt64)nextBlock * (SInt64)volumeBlockSize); // currently allocated PEOF bytesThisExtent = (SInt64)(nextBlock - fcb->ff_blocks) * (SInt64)volumeBlockSize; if (bytesThisExtent != 0) { fcb->ff_blocks = nextBlock; FTOC(fcb)->c_blocks += (bytesThisExtent / volumeBlockSize); FTOC(fcb)->c_flag |= C_MODIFIED; bytesToAdd -= bytesThisExtent; } // // Allocate some more space. // // First try a contiguous allocation (of the whole amount). // If that fails, get whatever we can. // If forceContig, then take whatever we got // else, keep getting bits and pieces (non-contig) err = noErr; wantContig = true; vcb->vcbFreeExtCnt = 0; /* For now, force rebuild of free extent list */ do { if (blockHint != 0) startBlock = blockHint; else startBlock = foundData[foundIndex].startBlock + foundData[foundIndex].blockCount; /* Force reserve checking if requested. */ if (flags & kEFReserveMask) { SInt64 availbytes; actualNumBlocks = 0; actualStartBlock = 0; availbytes = (SInt64)hfs_freeblks(VCBTOHFS(vcb), 1) * (SInt64)volumeBlockSize; if (availbytes <= 0) { err = dskFulErr; } else { if (wantContig && (availbytes < bytesToAdd)) err = dskFulErr; else { err = BlockAllocate( vcb, startBlock, MIN(bytesToAdd, availbytes), MIN(maximumBytes, availbytes), wantContig, &actualStartBlock, &actualNumBlocks); } } } else { err = BlockAllocate(vcb, startBlock, bytesToAdd, maximumBytes, wantContig, &actualStartBlock, &actualNumBlocks); } if (err == dskFulErr) { if (forceContig) break; // AllocContig failed because not enough contiguous space if (wantContig) { // Couldn't get one big chunk, so get whatever we can. err = noErr; wantContig = false; continue; } if (actualNumBlocks != 0) err = noErr; } if (err == noErr) { // Add the new extent to the existing extent record, or create a new one. if ((actualStartBlock == startBlock) && (blockHint == 0)) { // We grew the file's last extent, so just adjust the number of blocks. foundData[foundIndex].blockCount += actualNumBlocks; err = UpdateExtentRecord(vcb, fcb, &foundKey, foundData, hint); if (err != noErr) break; } else { UInt16 i; // Need to add a new extent. See if there is room in the current record. if (foundData[foundIndex].blockCount != 0) // Is current extent free to use? ++foundIndex; // No, so use the next one. if (foundIndex == numExtentsPerRecord) { // This record is full. Need to create a new one. if (FTOC(fcb)->c_fileid == kHFSExtentsFileID) { (void) BlockDeallocate(vcb, actualStartBlock, actualNumBlocks); err = dskFulErr; // Oops. Can't extend extents file past first record. break; } foundKey.keyLength = kHFSPlusExtentKeyMaximumLength; if (FORK_IS_RSRC(fcb)) foundKey.forkType = kResourceForkType; else foundKey.forkType = kDataForkType; foundKey.pad = 0; foundKey.fileID = FTOC(fcb)->c_fileid; foundKey.startBlock = nextBlock; foundData[0].startBlock = actualStartBlock; foundData[0].blockCount = actualNumBlocks; // zero out remaining extents... for (i = 1; i < kHFSPlusExtentDensity; ++i) { foundData[i].startBlock = 0; foundData[i].blockCount = 0; } foundIndex = 0; err = CreateExtentRecord(vcb, &foundKey, foundData, &hint); if (err == fxOvFlErr) { // We couldn't create an extent record because extents B-tree // couldn't grow. Dellocate the extent just allocated and // return a disk full error. (void) BlockDeallocate(vcb, actualStartBlock, actualNumBlocks); err = dskFulErr; } if (err != noErr) break; needsFlush = true; // We need to update the B-tree header } else { // Add a new extent into this record and update. foundData[foundIndex].startBlock = actualStartBlock; foundData[foundIndex].blockCount = actualNumBlocks; err = UpdateExtentRecord(vcb, fcb, &foundKey, foundData, hint); if (err != noErr) break; } } // Figure out how many bytes were actually allocated. // NOTE: BlockAllocate could have allocated more than we asked for. // Don't set the PEOF beyond what our client asked for. nextBlock += actualNumBlocks; bytesThisExtent = (SInt64)((SInt64)actualNumBlocks * (SInt64)volumeBlockSize); if (bytesThisExtent > bytesToAdd) { bytesToAdd = 0; } else { bytesToAdd -= bytesThisExtent; maximumBytes -= bytesThisExtent; } fcb->ff_blocks += (bytesThisExtent / volumeBlockSize); FTOC(fcb)->c_blocks += (bytesThisExtent / volumeBlockSize); FTOC(fcb)->c_flag |= C_MODIFIED; // If contiguous allocation was requested, then we've already got one contiguous // chunk. If we didn't get all we wanted, then adjust the error to disk full. if (forceContig) { if (bytesToAdd != 0) err = dskFulErr; break; // We've already got everything that's contiguous } } } while (err == noErr && bytesToAdd); ErrorExit: Exit: *actualBytesAdded = (SInt64)(fcb->ff_blocks - prevblocks) * (SInt64)volumeBlockSize; if (needsFlush) (void) FlushExtentFile(vcb); return err; Overflow: err = fileBoundsErr; goto ErrorExit; } //_________________________________________________________________________________ // // Routine: TruncateFileC // // Function: Truncates the disk space allocated to a file. The file space is // truncated to a specified new PEOF rounded up to the next allocation // block boundry. If the 'TFTrunExt' option is specified, the file is // truncated to the end of the extent containing the new PEOF. // // Input: A2.L - VCB pointer // A1.L - pointer to FCB array // D1.W - file refnum // D2.B - option flags // TFTrunExt - truncate to the extent containing new PEOF // D3.L - new PEOF // // Output: D0.W - result code // 0 = ok // -n = IO error // // Note: TruncateFile updates the PEOF in the FCB. //_________________________________________________________________________________ OSErr TruncateFileC ( ExtendedVCB *vcb, // volume that file resides on FCB *fcb, // FCB of file to truncate SInt64 peof, // new physical size for file Boolean truncateToExtent) // if true, truncate to end of extent containing newPEOF { OSErr err; UInt32 nextBlock; // next file allocation block to consider UInt32 startBlock; // Physical (volume) allocation block number of start of a range UInt32 physNumBlocks; // Number of allocation blocks in file (according to PEOF) UInt32 numBlocks; HFSPlusExtentKey key; // key for current extent record; key->keyLength == 0 if FCB's extent record UInt32 hint; // BTree hint corresponding to key HFSPlusExtentRecord extentRecord; UInt32 extentIndex; UInt32 extentNextBlock; UInt32 numExtentsPerRecord; SInt64 temp64; UInt8 forkType; Boolean extentChanged; // true if we actually changed an extent Boolean recordDeleted; // true if an extent record got deleted recordDeleted = false; if (vcb->vcbSigWord == kHFSPlusSigWord) numExtentsPerRecord = kHFSPlusExtentDensity; else numExtentsPerRecord = kHFSExtentDensity; if (FORK_IS_RSRC(fcb)) forkType = kResourceForkType; else forkType = kDataForkType; temp64 = fcb->ff_blocks; physNumBlocks = (UInt32)temp64; // // Round newPEOF up to a multiple of the allocation block size. If new size is // two gigabytes or more, then round down by one allocation block (??? really? // shouldn't that be an error?). // nextBlock = FileBytesToBlocks(peof, vcb->blockSize); // number of allocation blocks to remain in file peof = (SInt64)((SInt64)nextBlock * (SInt64)vcb->blockSize); // number of bytes in those blocks if ((vcb->vcbSigWord == kHFSSigWord) && (peof >= kTwoGigabytes)) { #if DEBUG_BUILD DebugStr("\pHFS: Trying to truncate a file to 2GB or more"); #endif err = fileBoundsErr; goto ErrorExit; } // // Update FCB's length // numBlocks = peof / vcb->blockSize; FTOC(fcb)->c_blocks -= (fcb->ff_blocks - numBlocks); fcb->ff_blocks = numBlocks; FTOC(fcb)->c_flag |= C_MODIFIED; // // If the new PEOF is 0, then truncateToExtent has no meaning (we should always deallocate // all storage). // if (peof == 0) { int i; // Deallocate all the extents for this fork err = DeallocateFork(vcb, FTOC(fcb)->c_fileid, forkType, fcb->fcbExtents, &recordDeleted); if (err != noErr) goto ErrorExit; // got some error, so return it // Update the catalog extent record (making sure it's zeroed out) if (err == noErr) { for (i=0; i < kHFSPlusExtentDensity; i++) { fcb->fcbExtents[i].startBlock = 0; fcb->fcbExtents[i].blockCount = 0; } } goto Done; } // // Find the extent containing byte (peof-1). This is the last extent we'll keep. // (If truncateToExtent is true, we'll keep the whole extent; otherwise, we'll only // keep up through peof). The search will tell us how many allocation blocks exist // in the found extent plus all previous extents. // err = SearchExtentFile(vcb, fcb, peof-1, &key, extentRecord, &extentIndex, &hint, &extentNextBlock); if (err != noErr) goto ErrorExit; extentChanged = false; // haven't changed the extent yet if (!truncateToExtent) { // // Shorten this extent. It may be the case that the entire extent gets // freed here. // numBlocks = extentNextBlock - nextBlock; // How many blocks in this extent to free up if (numBlocks != 0) { // Compute first volume allocation block to free startBlock = extentRecord[extentIndex].startBlock + extentRecord[extentIndex].blockCount - numBlocks; // Free the blocks in bitmap err = BlockDeallocate(vcb, startBlock, numBlocks); if (err != noErr) goto ErrorExit; // Adjust length of this extent extentRecord[extentIndex].blockCount -= numBlocks; // If extent is empty, set start block to 0 if (extentRecord[extentIndex].blockCount == 0) extentRecord[extentIndex].startBlock = 0; // Remember that we changed the extent record extentChanged = true; } } // // Now move to the next extent in the record, and set up the file allocation block number // nextBlock = extentNextBlock; // Next file allocation block to free ++extentIndex; // Its index within the extent record // // Release all following extents in this extent record. Update the record. // while (extentIndex < numExtentsPerRecord && extentRecord[extentIndex].blockCount != 0) { numBlocks = extentRecord[extentIndex].blockCount; // Deallocate this extent err = BlockDeallocate(vcb, extentRecord[extentIndex].startBlock, numBlocks); if (err != noErr) goto ErrorExit; // Update next file allocation block number nextBlock += numBlocks; // Zero out start and length of this extent to delete it from record extentRecord[extentIndex].startBlock = 0; extentRecord[extentIndex].blockCount = 0; // Remember that we changed an extent extentChanged = true; // Move to next extent in record ++extentIndex; } // // If any of the extents in the current record were changed, then update that // record (in the FCB, or extents file). // if (extentChanged) { err = UpdateExtentRecord(vcb, fcb, &key, extentRecord, hint); if (err != noErr) goto ErrorExit; } // // If there are any following allocation blocks, then we need // to seach for their extent records and delete those allocation // blocks. // if (nextBlock < physNumBlocks) err = TruncateExtents(vcb, forkType, FTOC(fcb)->c_fileid, nextBlock, &recordDeleted); Done: ErrorExit: if (recordDeleted) (void) FlushExtentFile(vcb); return err; } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: SearchExtentRecord (was XRSearch) // // Function: Searches extent record for the extent mapping a given file // allocation block number (FABN). // // Input: searchFABN - desired FABN // extentData - pointer to extent data record (xdr) // extentDataStartFABN - beginning FABN for extent record // // Output: foundExtentDataOffset - offset to extent entry within xdr // result = noErr, offset to extent mapping desired FABN // result = FXRangeErr, offset to last extent in record // endingFABNPlusOne - ending FABN +1 // noMoreExtents - True if the extent was not found, and the // extent record was not full (so don't bother // looking in subsequent records); false otherwise. // // Result: noErr = ok // FXRangeErr = desired FABN > last mapped FABN in record //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ static OSErr SearchExtentRecord( const ExtendedVCB *vcb, UInt32 searchFABN, const HFSPlusExtentRecord extentData, UInt32 extentDataStartFABN, UInt32 *foundExtentIndex, UInt32 *endingFABNPlusOne, Boolean *noMoreExtents) { OSErr err = noErr; UInt32 extentIndex; UInt32 numberOfExtents; UInt32 numAllocationBlocks; Boolean foundExtent; *endingFABNPlusOne = extentDataStartFABN; *noMoreExtents = false; foundExtent = false; if (vcb->vcbSigWord == kHFSPlusSigWord) numberOfExtents = kHFSPlusExtentDensity; else numberOfExtents = kHFSExtentDensity; for( extentIndex = 0; extentIndex < numberOfExtents; ++extentIndex ) { // Loop over the extent record and find the search FABN. numAllocationBlocks = extentData[extentIndex].blockCount; if ( numAllocationBlocks == 0 ) { break; } *endingFABNPlusOne += numAllocationBlocks; if( searchFABN < *endingFABNPlusOne ) { // Found the extent. foundExtent = true; break; } } if( foundExtent ) { // Found the extent. Note the extent offset *foundExtentIndex = extentIndex; } else { // Did not find the extent. Set foundExtentDataOffset accordingly if( extentIndex > 0 ) { *foundExtentIndex = extentIndex - 1; } else { *foundExtentIndex = 0; } // If we found an empty extent, then set noMoreExtents. if (extentIndex < numberOfExtents) *noMoreExtents = true; // Finally, return an error to the caller err = fxRangeErr; } return( err ); } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: SearchExtentFile (was XFSearch) // // Function: Searches extent file (including the FCB resident extent record) // for the extent mapping a given file position. // // Input: vcb - VCB pointer // fcb - FCB pointer // filePosition - file position (byte address) // // Output: foundExtentKey - extent key record (xkr) // If extent was found in the FCB's resident extent record, // then foundExtentKey->keyLength will be set to 0. // foundExtentData - extent data record(xdr) // foundExtentIndex - index to extent entry in xdr // result = 0, offset to extent mapping desired FABN // result = FXRangeErr, offset to last extent in record // (i.e., kNumExtentsPerRecord-1) // extentBTreeHint - BTree hint for extent record // kNoHint = Resident extent record // endingFABNPlusOne - ending FABN +1 // // Result: // noErr Found an extent that contains the given file position // FXRangeErr Given position is beyond the last allocated extent // (other) (some other internal I/O error) //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ static OSErr SearchExtentFile( const ExtendedVCB *vcb, const FCB *fcb, SInt64 filePosition, HFSPlusExtentKey *foundExtentKey, HFSPlusExtentRecord foundExtentData, UInt32 *foundExtentIndex, UInt32 *extentBTreeHint, UInt32 *endingFABNPlusOne ) { OSErr err; UInt32 filePositionBlock; SInt64 temp64; Boolean noMoreExtents; temp64 = filePosition / (SInt64)vcb->blockSize; filePositionBlock = (UInt32)temp64; bcopy ( fcb->fcbExtents, foundExtentData, sizeof(HFSPlusExtentRecord)); // Search the resident FCB first. err = SearchExtentRecord( vcb, filePositionBlock, foundExtentData, 0, foundExtentIndex, endingFABNPlusOne, &noMoreExtents ); if( err == noErr ) { // Found the extent. Set results accordingly *extentBTreeHint = kNoHint; // no hint, because not in the BTree foundExtentKey->keyLength = 0; // 0 = the FCB itself goto Exit; } // Didn't find extent in FCB. If FCB's extent record wasn't full, there's no point // in searching the extents file. Note that SearchExtentRecord left us pointing at // the last valid extent (or the first one, if none were valid). This means we need // to fill in the hint and key outputs, just like the "if" statement above. if ( noMoreExtents ) { *extentBTreeHint = kNoHint; // no hint, because not in the BTree foundExtentKey->keyLength = 0; // 0 = the FCB itself err = fxRangeErr; // There are no more extents, so must be beyond PEOF goto Exit; } // // Find the desired record, or the previous record if it is the same fork // err = FindExtentRecord(vcb, FORK_IS_RSRC(fcb) ? kResourceForkType : kDataForkType, FTOC(fcb)->c_fileid, filePositionBlock, true, foundExtentKey, foundExtentData, extentBTreeHint); if (err == btNotFound) { // // If we get here, the desired position is beyond the extents in the FCB, and there are no extents // in the extents file. Return the FCB's extents and a range error. // *extentBTreeHint = kNoHint; foundExtentKey->keyLength = 0; err = GetFCBExtentRecord(fcb, foundExtentData); // Note: foundExtentIndex and endingFABNPlusOne have already been set as a result of the very // first SearchExtentRecord call in this function (when searching in the FCB's extents, and // we got a range error). return fxRangeErr; } // // If we get here, there was either a BTree error, or we found an appropriate record. // If we found a record, then search it for the correct index into the extents. // if (err == noErr) { // Find appropriate index into extent record err = SearchExtentRecord(vcb, filePositionBlock, foundExtentData, foundExtentKey->startBlock, foundExtentIndex, endingFABNPlusOne, &noMoreExtents); } Exit: return err; } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: UpdateExtentRecord // // Function: Write new extent data to an existing extent record with a given key. // If all of the extents are empty, and the extent record is in the // extents file, then the record is deleted. // // Input: vcb - the volume containing the extents // fcb - the file that owns the extents // extentFileKey - pointer to extent key record (xkr) // If the key length is 0, then the extents are actually part // of the catalog record, stored in the FCB. // extentData - pointer to extent data record (xdr) // extentBTreeHint - hint for given key, or kNoHint // // Result: noErr = ok // (other) = error from BTree //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ static OSErr UpdateExtentRecord ( const ExtendedVCB *vcb, FCB *fcb, const HFSPlusExtentKey *extentFileKey, const HFSPlusExtentRecord extentData, UInt32 extentBTreeHint) { OSErr err = noErr; if (extentFileKey->keyLength == 0) { // keyLength == 0 means the FCB's extent record BlockMoveData(extentData, fcb->fcbExtents, sizeof(HFSPlusExtentRecord)); FTOC(fcb)->c_flag |= C_MODIFIED; } else { BTreeIterator * btIterator; FSBufferDescriptor btRecord; UInt16 btRecordSize; FCB * btFCB; // // Need to find and change a record in Extents BTree // btFCB = GetFileControlBlock(vcb->extentsRefNum); // XXXdbg - preflight that there's enough space err = BTCheckFreeSpace(btFCB); if (err) return err; MALLOC(btIterator, BTreeIterator *, sizeof(*btIterator), M_TEMP, M_WAITOK); bzero(btIterator, sizeof(*btIterator)); if (vcb->vcbSigWord == kHFSSigWord) { HFSExtentKey * key; // Actual extent key used on disk in HFS HFSExtentRecord foundData; // The extent data actually found key = (HFSExtentKey*) &btIterator->key; key->keyLength = kHFSExtentKeyMaximumLength; key->forkType = extentFileKey->forkType; key->fileID = extentFileKey->fileID; key->startBlock = extentFileKey->startBlock; btIterator->hint.index = 0; btIterator->hint.nodeNum = extentBTreeHint; btRecord.bufferAddress = &foundData; btRecord.itemSize = sizeof(HFSExtentRecord); btRecord.itemCount = 1; err = BTSearchRecord(btFCB, btIterator, &btRecord, &btRecordSize, btIterator); if (err == noErr) err = HFSPlusToHFSExtents(extentData, (HFSExtentDescriptor *)&foundData); if (err == noErr) err = BTReplaceRecord(btFCB, btIterator, &btRecord, btRecordSize); (void) BTFlushPath(btFCB); } else { // HFS Plus volume HFSPlusExtentRecord foundData; // The extent data actually found BlockMoveData(extentFileKey, &btIterator->key, sizeof(HFSPlusExtentKey)); btIterator->hint.index = 0; btIterator->hint.nodeNum = extentBTreeHint; btRecord.bufferAddress = &foundData; btRecord.itemSize = sizeof(HFSPlusExtentRecord); btRecord.itemCount = 1; err = BTSearchRecord(btFCB, btIterator, &btRecord, &btRecordSize, btIterator); if (err == noErr) { BlockMoveData(extentData, &foundData, sizeof(HFSPlusExtentRecord)); err = BTReplaceRecord(btFCB, btIterator, &btRecord, btRecordSize); } (void) BTFlushPath(btFCB); } FREE(btIterator, M_TEMP); } return err; } void HFSToHFSPlusExtents( const HFSExtentRecord oldExtents, HFSPlusExtentRecord newExtents) { UInt32 i; // copy the first 3 extents newExtents[0].startBlock = oldExtents[0].startBlock; newExtents[0].blockCount = oldExtents[0].blockCount; newExtents[1].startBlock = oldExtents[1].startBlock; newExtents[1].blockCount = oldExtents[1].blockCount; newExtents[2].startBlock = oldExtents[2].startBlock; newExtents[2].blockCount = oldExtents[2].blockCount; // zero out the remaining ones for (i = 3; i < kHFSPlusExtentDensity; ++i) { newExtents[i].startBlock = 0; newExtents[i].blockCount = 0; } } OSErr HFSPlusToHFSExtents( const HFSPlusExtentRecord oldExtents, HFSExtentRecord newExtents) { OSErr err; err = noErr; // copy the first 3 extents newExtents[0].startBlock = oldExtents[0].startBlock; newExtents[0].blockCount = oldExtents[0].blockCount; newExtents[1].startBlock = oldExtents[1].startBlock; newExtents[1].blockCount = oldExtents[1].blockCount; newExtents[2].startBlock = oldExtents[2].startBlock; newExtents[2].blockCount = oldExtents[2].blockCount; #if DEBUG_BUILD if (oldExtents[3].startBlock || oldExtents[3].blockCount) { DebugStr("\pExtentRecord with > 3 extents is invalid for HFS"); err = fsDSIntErr; } #endif return err; } OSErr GetFCBExtentRecord( const FCB *fcb, HFSPlusExtentRecord extents) { BlockMoveData(fcb->fcbExtents, extents, sizeof(HFSPlusExtentRecord)); return noErr; } //_________________________________________________________________________________ // // Routine: ExtentsAreIntegral // // Purpose: Ensure that each extent can hold an integral number of nodes // Called by the NodesAreContiguous function //_________________________________________________________________________________ static Boolean ExtentsAreIntegral( const HFSPlusExtentRecord extentRecord, UInt32 mask, UInt32 *blocksChecked, Boolean *checkedLastExtent) { UInt32 blocks; UInt32 extentIndex; *blocksChecked = 0; *checkedLastExtent = false; for(extentIndex = 0; extentIndex < kHFSPlusExtentDensity; extentIndex++) { blocks = extentRecord[extentIndex].blockCount; if ( blocks == 0 ) { *checkedLastExtent = true; break; } *blocksChecked += blocks; if (blocks & mask) return false; } return true; } //_________________________________________________________________________________ // // Routine: NodesAreContiguous // // Purpose: Ensure that all b-tree nodes are contiguous on disk // Called by BTOpenPath during volume mount //_________________________________________________________________________________ Boolean NodesAreContiguous( ExtendedVCB *vcb, FCB *fcb, UInt32 nodeSize) { UInt32 mask; UInt32 startBlock; UInt32 blocksChecked; UInt32 hint; HFSPlusExtentKey key; HFSPlusExtentRecord extents; OSErr result; Boolean lastExtentReached; if (vcb->blockSize >= nodeSize) return TRUE; mask = (nodeSize / vcb->blockSize) - 1; // check the local extents (void) GetFCBExtentRecord(fcb, extents); if ( !ExtentsAreIntegral(extents, mask, &blocksChecked, &lastExtentReached) ) return FALSE; if (lastExtentReached || (SInt64)((SInt64)blocksChecked * (SInt64)vcb->blockSize) >= fcb->ff_size) return TRUE; startBlock = blocksChecked; // check the overflow extents (if any) while ( !lastExtentReached ) { result = FindExtentRecord(vcb, kDataForkType, fcb->ff_cp->c_fileid, startBlock, FALSE, &key, extents, &hint); if (result) break; if ( !ExtentsAreIntegral(extents, mask, &blocksChecked, &lastExtentReached) ) return FALSE; startBlock += blocksChecked; } return TRUE; }