/* * Copyright (c) 2000-2013 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The 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, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ #include "../../hfs.h" #include "../../hfs_format.h" #include "../../hfs_endian.h" #include "../headers/FileMgrInternal.h" #include "../headers/BTreesInternal.h" #include /* ============================================================ Public (Exported) Routines: ============================================================ 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. ============================================================ 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. */ #if CONFIG_HFS_STD static const int64_t kTwoGigabytes = 0x80000000LL; #endif enum { kDataForkType = 0, kResourceForkType = 0xFF, kPreviousRecord = -1 }; #if CONFIG_HFS_STD static OSErr HFSPlusToHFSExtents( const HFSPlusExtentRecord oldExtents, HFSExtentRecord newExtents); #endif static OSErr FindExtentRecord( const ExtendedVCB *vcb, u_int8_t forkType, u_int32_t fileID, u_int32_t startBlock, Boolean allowPrevious, HFSPlusExtentKey *foundKey, HFSPlusExtentRecord foundData, u_int32_t *foundHint); static OSErr DeleteExtentRecord( const ExtendedVCB *vcb, u_int8_t forkType, u_int32_t fileID, u_int32_t startBlock); static OSErr CreateExtentRecord( ExtendedVCB *vcb, HFSPlusExtentKey *key, HFSPlusExtentRecord extents, u_int32_t *hint); static OSErr GetFCBExtentRecord( const FCB *fcb, HFSPlusExtentRecord extents); static OSErr SearchExtentFile( ExtendedVCB *vcb, const FCB *fcb, int64_t filePosition, HFSPlusExtentKey *foundExtentKey, HFSPlusExtentRecord foundExtentData, u_int32_t *foundExtentDataIndex, u_int32_t *extentBTreeHint, u_int32_t *endingFABNPlusOne ); static OSErr SearchExtentRecord( ExtendedVCB *vcb, u_int32_t searchFABN, const HFSPlusExtentRecord extentData, u_int32_t extentDataStartFABN, u_int32_t *foundExtentDataOffset, u_int32_t *endingFABNPlusOne, Boolean *noMoreExtents); static OSErr ReleaseExtents( ExtendedVCB *vcb, const HFSPlusExtentRecord extentRecord, u_int32_t *numReleasedAllocationBlocks, Boolean *releasedLastExtent); static OSErr DeallocateFork( ExtendedVCB *vcb, HFSCatalogNodeID fileID, u_int8_t forkType, HFSPlusExtentRecord catalogExtents, Boolean * recordDeleted); static OSErr TruncateExtents( ExtendedVCB *vcb, u_int8_t forkType, u_int32_t fileID, u_int32_t startBlock, Boolean * recordDeleted); static OSErr UpdateExtentRecord ( ExtendedVCB *vcb, FCB *fcb, int deleted, const HFSPlusExtentKey *extentFileKey, const HFSPlusExtentRecord extentData, u_int32_t extentBTreeHint); static Boolean ExtentsAreIntegral( const HFSPlusExtentRecord extentRecord, u_int32_t mask, u_int32_t *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 //_________________________________________________________________________________ static OSErr FindExtentRecord( const ExtendedVCB *vcb, u_int8_t forkType, u_int32_t fileID, u_int32_t startBlock, Boolean allowPrevious, HFSPlusExtentKey *foundKey, HFSPlusExtentRecord foundData, u_int32_t *foundHint) { FCB * fcb; struct BTreeIterator *btIterator = NULL; FSBufferDescriptor btRecord; OSErr err; u_int16_t btRecordSize; err = noErr; if (foundHint) *foundHint = 0; fcb = GetFileControlBlock(vcb->extentsRefNum); MALLOC (btIterator, struct BTreeIterator*, sizeof(struct BTreeIterator), M_TEMP, M_WAITOK); if (btIterator == NULL) { return memFullErr; // translates to ENOMEM } bzero(btIterator, sizeof(*btIterator)); /* HFS Plus / HFSX */ if (vcb->vcbSigWord != kHFSSigWord) { 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 if (foundKey) BlockMoveData(extentKeyPtr, foundKey, sizeof(HFSPlusExtentKey)); // Copy the found data back for the caller BlockMoveData(&extentData, foundData, sizeof(HFSPlusExtentRecord)); } } #if CONFIG_HFS_STD else { 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) { u_int16_t i; // Copy the found key back for the caller if (foundKey) { 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; } } } #endif if (foundHint) *foundHint = btIterator->hint.nodeNum; FREE(btIterator, M_TEMP); return err; } static OSErr CreateExtentRecord( ExtendedVCB *vcb, HFSPlusExtentKey *key, HFSPlusExtentRecord extents, u_int32_t *hint) { struct BTreeIterator *btIterator = NULL; FSBufferDescriptor btRecord; u_int16_t btRecordSize; int lockflags; OSErr err; err = noErr; *hint = 0; MALLOC (btIterator, struct BTreeIterator*, sizeof(struct BTreeIterator), M_TEMP, M_WAITOK); if (btIterator == NULL) { return memFullErr; // translates to ENOMEM } bzero(btIterator, sizeof(*btIterator)); /* * The lock taken by callers of ExtendFileC is speculative and * only occurs when the file already has overflow extents. So * We need to make sure we have the lock here. The extents * btree lock can be nested (its recursive) so we always take * it here. */ lockflags = hfs_systemfile_lock(vcb, SFL_EXTENTS, HFS_EXCLUSIVE_LOCK); /* HFS+/HFSX */ if (vcb->vcbSigWord != kHFSSigWord) { btRecordSize = sizeof(HFSPlusExtentRecord); btRecord.bufferAddress = extents; btRecord.itemSize = btRecordSize; btRecord.itemCount = 1; BlockMoveData(key, &btIterator->key, sizeof(HFSPlusExtentKey)); } #if CONFIG_HFS_STD else { /* HFS Standard */ 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); } #endif if (err == noErr) err = BTInsertRecord(GetFileControlBlock(vcb->extentsRefNum), btIterator, &btRecord, btRecordSize); if (err == noErr) *hint = btIterator->hint.nodeNum; (void) BTFlushPath(GetFileControlBlock(vcb->extentsRefNum)); hfs_systemfile_unlock(vcb, lockflags); FREE (btIterator, M_TEMP); return err; } static OSErr DeleteExtentRecord( const ExtendedVCB *vcb, u_int8_t forkType, u_int32_t fileID, u_int32_t startBlock) { struct BTreeIterator *btIterator = NULL; OSErr err; err = noErr; MALLOC (btIterator, struct BTreeIterator*, sizeof(struct BTreeIterator), M_TEMP, M_WAITOK); if (btIterator == NULL) { return memFullErr; // translates to ENOMEM } bzero(btIterator, sizeof(*btIterator)); /* HFS+ / HFSX */ if (vcb->vcbSigWord != kHFSSigWord) { // HFS Plus volume HFSPlusExtentKey * keyPtr; keyPtr = (HFSPlusExtentKey*) &btIterator->key; keyPtr->keyLength = kHFSPlusExtentKeyMaximumLength; keyPtr->forkType = forkType; keyPtr->pad = 0; keyPtr->fileID = fileID; keyPtr->startBlock = startBlock; } #if CONFIG_HFS_STD else { /* HFS standard */ HFSExtentKey * keyPtr; keyPtr = (HFSExtentKey*) &btIterator->key; keyPtr->keyLength = kHFSExtentKeyMaximumLength; keyPtr->forkType = forkType; keyPtr->fileID = fileID; keyPtr->startBlock = startBlock; } #endif 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. // //_________________________________________________________________________________ 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) daddr64_t *startSector, // first sector (NOT an allocation block) size_t *availableBytes) // number of contiguous bytes (up to numberOfBytes) { OSErr err; u_int32_t allocBlockSize; // Size of the volume's allocation block u_int32_t sectorSize; HFSPlusExtentKey foundKey; HFSPlusExtentRecord foundData; u_int32_t foundIndex; u_int32_t hint; u_int32_t firstFABN; // file allocation block of first block in found extent u_int32_t nextFABN; // file allocation block of block after end of found extent off_t dataEnd; // (offset) end of range that is contiguous u_int32_t sectorsPerBlock; // Number of sectors per allocation block u_int32_t startBlock; // volume allocation block corresponding to firstFABN daddr64_t temp; off_t tmpOff; allocBlockSize = vcb->blockSize; sectorSize = VCBTOHFS(vcb)->hfs_logical_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 = (daddr64_t)((offset - (off_t)((off_t)(firstFABN) * (off_t)(allocBlockSize)))/sectorSize); temp += (daddr64_t)startBlock * (daddr64_t)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). // if (availableBytes) { tmpOff = dataEnd - offset; /* * Disallow negative runs. */ if (tmpOff <= 0) { return EINVAL; } 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, u_int32_t *numReleasedAllocationBlocks, Boolean *releasedLastExtent) { u_int32_t extentIndex; u_int32_t numberOfExtents; OSErr err = noErr; *numReleasedAllocationBlocks = 0; *releasedLastExtent = false; if (vcb->vcbSigWord == kHFSPlusSigWord) numberOfExtents = kHFSPlusExtentDensity; else numberOfExtents = kHFSExtentDensity; for( extentIndex = 0; extentIndex < numberOfExtents; extentIndex++) { u_int32_t 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 , 0); 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, u_int8_t forkType, u_int32_t fileID, u_int32_t startBlock, Boolean * recordDeleted) { OSErr err; u_int32_t numberExtentsReleased; Boolean releasedLastExtent; u_int32_t hint; HFSPlusExtentKey key; HFSPlusExtentRecord extents; int lockflags; /* * The lock taken by callers of TruncateFileC is speculative and * only occurs when the file already has overflow extents. So * We need to make sure we have the lock here. The extents * btree lock can be nested (its recursive) so we always take * it here. */ lockflags = hfs_systemfile_lock(vcb, SFL_EXTENTS, HFS_EXCLUSIVE_LOCK); 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; } hfs_systemfile_unlock(vcb, lockflags); return err; } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: DeallocateFork // // Function: De-allocates all disk space allocated to a specified fork. //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ static OSErr DeallocateFork( ExtendedVCB *vcb, HFSCatalogNodeID fileID, u_int8_t forkType, HFSPlusExtentRecord catalogExtents, Boolean * recordDeleted) /* true if a record was deleted */ { OSErr err; u_int32_t 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; int lockflags; fcb = GetFileControlBlock(vcb->extentsRefNum); lockflags = hfs_systemfile_lock(vcb, SFL_EXTENTS, HFS_EXCLUSIVE_LOCK); err = BTFlushPath(fcb); hfs_systemfile_unlock(vcb, lockflags); 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 ); } #if CONFIG_HFS_STD //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: CompareExtentKeys // // Function: Compares two extent file keys (a search key and a trial key) for // an HFS volume. //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ __private_extern__ int32_t CompareExtentKeys( const HFSExtentKey *searchKey, const HFSExtentKey *trialKey ) { int32_t result; // ± 1 #if DEBUG_BUILD if (searchKey->keyLength != kHFSExtentKeyMaximumLength) DebugStr("HFS: search Key is wrong length"); if (trialKey->keyLength != kHFSExtentKeyMaximumLength) DebugStr("HFS: 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 ); } #endif //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // Routine: CompareExtentKeysPlus // // Function: Compares two extent file keys (a search key and a trial key) for // an HFS volume. //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ __private_extern__ int32_t CompareExtentKeysPlus( const HFSPlusExtentKey *searchKey, const HFSPlusExtentKey *trialKey ) { int32_t result; // ± 1 #if DEBUG_BUILD if (searchKey->keyLength != kHFSPlusExtentKeyMaximumLength) DebugStr("HFS: search Key is wrong length"); if (trialKey->keyLength != kHFSPlusExtentKeyMaximumLength) DebugStr("HFS: 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 ); } /* * Add a file extent to a file. * * Used by hfs_extendfs to extend the volume allocation bitmap file. * */ int AddFileExtent(ExtendedVCB *vcb, FCB *fcb, u_int32_t startBlock, u_int32_t blockCount) { HFSPlusExtentKey foundKey; HFSPlusExtentRecord foundData; u_int32_t foundIndex; u_int32_t hint; u_int32_t nextBlock; int64_t peof; int i; int error; peof = (int64_t)(fcb->ff_blocks + blockCount) * (int64_t)vcb->blockSize; error = SearchExtentFile(vcb, fcb, peof-1, &foundKey, foundData, &foundIndex, &hint, &nextBlock); if (error != fxRangeErr) return (EBUSY); /* * Add new extent. See if there is room in the current record. */ if (foundData[foundIndex].blockCount != 0) ++foundIndex; if (foundIndex == kHFSPlusExtentDensity) { /* * Existing record is full so create a new one. */ foundKey.keyLength = kHFSPlusExtentKeyMaximumLength; foundKey.forkType = kDataForkType; foundKey.pad = 0; foundKey.fileID = FTOC(fcb)->c_fileid; foundKey.startBlock = nextBlock; foundData[0].startBlock = startBlock; foundData[0].blockCount = blockCount; /* zero out remaining extents. */ for (i = 1; i < kHFSPlusExtentDensity; ++i) { foundData[i].startBlock = 0; foundData[i].blockCount = 0; } foundIndex = 0; error = CreateExtentRecord(vcb, &foundKey, foundData, &hint); if (error == fxOvFlErr) error = dskFulErr; } else { /* * Add a new extent into existing record. */ foundData[foundIndex].startBlock = startBlock; foundData[foundIndex].blockCount = blockCount; error = UpdateExtentRecord(vcb, fcb, 0, &foundKey, foundData, hint); } (void) FlushExtentFile(vcb); return (error); } //_________________________________________________________________________________ // // Routine: Extendfile // // Function: Extends the disk space allocated to a file. // //_________________________________________________________________________________ OSErr ExtendFileC ( ExtendedVCB *vcb, // volume that file resides on FCB *fcb, // FCB of file to truncate int64_t bytesToAdd, // number of bytes to allocate u_int32_t blockHint, // desired starting allocation block u_int32_t flags, // EFContig and/or EFAll int64_t *actualBytesAdded) // number of bytes actually allocated { OSErr err; u_int32_t volumeBlockSize; int64_t blocksToAdd; int64_t bytesThisExtent; HFSPlusExtentKey foundKey; HFSPlusExtentRecord foundData; u_int32_t foundIndex; u_int32_t hint; u_int32_t nextBlock; u_int32_t startBlock; Boolean allOrNothing; Boolean forceContig; Boolean wantContig; Boolean useMetaZone; Boolean needsFlush; int allowFlushTxns; u_int32_t actualStartBlock; u_int32_t actualNumBlocks; u_int32_t numExtentsPerRecord; int64_t maximumBytes; int64_t availbytes; int64_t peof; u_int32_t prevblocks; struct hfsmount *hfsmp = (struct hfsmount*)vcb; allowFlushTxns = 0; needsFlush = false; *actualBytesAdded = 0; volumeBlockSize = vcb->blockSize; allOrNothing = ((flags & kEFAllMask) != 0); forceContig = ((flags & kEFContigMask) != 0); prevblocks = fcb->ff_blocks; if (vcb->vcbSigWord != kHFSSigWord) { numExtentsPerRecord = kHFSPlusExtentDensity; } #if CONFIG_HFS_STD else { /* HFS Standard */ numExtentsPerRecord = kHFSExtentDensity; /* Make sure the request and new PEOF are less than 2GB if HFS std*/ if (bytesToAdd >= kTwoGigabytes) goto HFS_Std_Overflow; if ((((int64_t)fcb->ff_blocks * (int64_t)volumeBlockSize) + bytesToAdd) >= kTwoGigabytes) goto HFS_Std_Overflow; } #endif // // Determine how many blocks need to be allocated. // Round up the number of desired bytes to add. // blocksToAdd = howmany(bytesToAdd, volumeBlockSize); bytesToAdd = (int64_t)((int64_t)blocksToAdd * (int64_t)volumeBlockSize); /* * For deferred allocations just reserve the blocks. */ if ((flags & kEFDeferMask) && (vcb->vcbSigWord == kHFSPlusSigWord) && (bytesToAdd < (int64_t)HFS_MAX_DEFERED_ALLOC) && (blocksToAdd < hfs_freeblks(VCBTOHFS(vcb), 1))) { hfs_lock_mount (hfsmp); vcb->loanedBlocks += blocksToAdd; hfs_unlock_mount(hfsmp); fcb->ff_unallocblocks += blocksToAdd; FTOC(fcb)->c_blocks += blocksToAdd; fcb->ff_blocks += blocksToAdd; FTOC(fcb)->c_flag |= C_MODIFIED | C_FORCEUPDATE; *actualBytesAdded = bytesToAdd; return (0); } /* * Give back any unallocated blocks before doing real allocations. */ if (fcb->ff_unallocblocks > 0) { u_int32_t loanedBlocks; loanedBlocks = fcb->ff_unallocblocks; blocksToAdd += loanedBlocks; bytesToAdd = (int64_t)blocksToAdd * (int64_t)volumeBlockSize; FTOC(fcb)->c_blocks -= loanedBlocks; fcb->ff_blocks -= loanedBlocks; fcb->ff_unallocblocks = 0; hfs_lock_mount(hfsmp); vcb->loanedBlocks -= loanedBlocks; hfs_unlock_mount(hfsmp); } // // 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 ((vcb->vcbClpSiz > (int32_t)volumeBlockSize) && (bytesToAdd < (int64_t)HFS_MAX_DEFERED_ALLOC) && (flags & kEFNoClumpMask) == 0) { maximumBytes = (int64_t)howmany(bytesToAdd, vcb->vcbClpSiz); maximumBytes *= vcb->vcbClpSiz; } else { maximumBytes = bytesToAdd; } #if CONFIG_HFS_STD // // Compute new physical EOF, rounded up to a multiple of a block. // if ( (vcb->vcbSigWord == kHFSSigWord) && // Too big? ((((int64_t)fcb->ff_blocks * (int64_t)volumeBlockSize) + bytesToAdd) >= kTwoGigabytes) ) { if (allOrNothing) // Yes, must they have it all? goto HFS_Std_Overflow; // Yes, can't have it else { --blocksToAdd; // No, give give 'em one block less bytesToAdd -= volumeBlockSize; } } #endif // // 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 = ((int64_t)fcb->ff_blocks * (int64_t)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 | C_FORCEUPDATE; 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 = (int64_t)((int64_t)nextBlock * (int64_t)volumeBlockSize); // currently allocated PEOF bytesThisExtent = (int64_t)(nextBlock - fcb->ff_blocks) * (int64_t)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) /* * Note that for sparse devices (like sparse bundle dmgs), we * should only be aggressive with re-using once-allocated pieces * if we're not dealing with system files. If we're trying to operate * on behalf of a system file, we need the maximum contiguous amount * possible. For non-system files we favor locality and fragmentation over * contiguity as it can result in fewer blocks being needed from the underlying * filesystem that the sparse image resides upon. */ err = noErr; if ( (vcb->hfs_flags & HFS_HAS_SPARSE_DEVICE) && (fcb->ff_cp->c_fileid >= kHFSFirstUserCatalogNodeID) && (flags & kEFMetadataMask) == 0) { /* * We want locality over contiguity so by default we set wantContig to * false unless we hit one of the circumstances below. */ wantContig = false; if (hfs_isrbtree_active(VCBTOHFS(vcb))) { /* * If the red-black tree is acive, we can always find a suitable contiguous * chunk. So if the user specifically requests contiguous files, we should * honor that no matter what kind of device it is. */ if (forceContig) { wantContig = true; } } else { /* * If the red-black tree is not active, then only set wantContig to true * if we have never done a contig scan on the device, which would populate * the free extent cache. Note that the caller may explicitly unset the * DID_CONTIG_SCAN bit in order to force us to vend a contiguous extent here * if the caller wants to get a contiguous chunk. */ if ((vcb->hfs_flags & HFS_DID_CONTIG_SCAN) == 0) { vcb->hfs_flags |= HFS_DID_CONTIG_SCAN; wantContig = true; } } } else { wantContig = true; } useMetaZone = flags & kEFMetadataMask; do { if (blockHint != 0) startBlock = blockHint; else startBlock = foundData[foundIndex].startBlock + foundData[foundIndex].blockCount; actualNumBlocks = 0; actualStartBlock = 0; /* Find number of free blocks based on reserved block flag option */ availbytes = (int64_t)hfs_freeblks(VCBTOHFS(vcb), flags & kEFReserveMask) * (int64_t)volumeBlockSize; if (availbytes <= 0) { err = dskFulErr; } else { if (wantContig && (availbytes < bytesToAdd)) { err = dskFulErr; } else { uint32_t ba_flags = 0; if (wantContig) { ba_flags |= HFS_ALLOC_FORCECONTIG; } if (useMetaZone) { ba_flags |= HFS_ALLOC_METAZONE; } if (allowFlushTxns) { ba_flags |= HFS_ALLOC_FLUSHTXN; } err = BlockAllocate( vcb, startBlock, howmany(MIN(bytesToAdd, availbytes), volumeBlockSize), howmany(MIN(maximumBytes, availbytes), volumeBlockSize), ba_flags, &actualStartBlock, &actualNumBlocks); } } if (err == dskFulErr) { if (forceContig) { if (allowFlushTxns == 0) { /* If we're forcing contiguity, re-try but allow plucking from recently freed regions */ allowFlushTxns = 1; wantContig = 1; err = noErr; continue; } else { 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 (useMetaZone == 0) { /* Couldn't get anything so dip into metadat zone */ err = noErr; useMetaZone = 1; continue; } /* If we couldn't find what we needed without flushing the journal, then go ahead and do it now */ if (allowFlushTxns == 0) { allowFlushTxns = 1; err = noErr; continue; } } if (err == noErr) { if (actualNumBlocks != 0) { // this catalog entry *must* get forced to disk when // hfs_update() is called FTOC(fcb)->c_flag |= C_FORCEUPDATE; } // 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, 0, &foundKey, foundData, hint); if (err != noErr) break; } else { u_int16_t 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, 0); 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, 0); 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, 0, &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 = (int64_t)((int64_t)actualNumBlocks * (int64_t)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 | C_FORCEUPDATE; // 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: if (VCBTOHFS(vcb)->hfs_flags & HFS_METADATA_ZONE) { /* Keep the roving allocator out of the metadata zone. */ if (vcb->nextAllocation >= VCBTOHFS(vcb)->hfs_metazone_start && vcb->nextAllocation <= VCBTOHFS(vcb)->hfs_metazone_end) { hfs_lock_mount (hfsmp); HFS_UPDATE_NEXT_ALLOCATION(vcb, VCBTOHFS(vcb)->hfs_metazone_end + 1); MarkVCBDirty(vcb); hfs_unlock_mount(hfsmp); } } if (prevblocks < fcb->ff_blocks) { *actualBytesAdded = (int64_t)(fcb->ff_blocks - prevblocks) * (int64_t)volumeBlockSize; } else { *actualBytesAdded = 0; } if (needsFlush) (void) FlushExtentFile(vcb); return err; #if CONFIG_HFS_STD HFS_Std_Overflow: err = fileBoundsErr; goto ErrorExit; #endif } //_________________________________________________________________________________ // // 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. // //_________________________________________________________________________________ OSErr TruncateFileC ( ExtendedVCB *vcb, // volume that file resides on FCB *fcb, // FCB of file to truncate int64_t peof, // new physical size for file int deleted, // if nonzero, the file's catalog record has already been deleted. int rsrc, // does this represent a resource fork or not? uint32_t fileid, // the fileid of the file we're manipulating. Boolean truncateToExtent) // if true, truncate to end of extent containing newPEOF { OSErr err; u_int32_t nextBlock; // next file allocation block to consider u_int32_t startBlock; // Physical (volume) allocation block number of start of a range u_int32_t physNumBlocks; // Number of allocation blocks in file (according to PEOF) u_int32_t numBlocks; HFSPlusExtentKey key; // key for current extent record; key->keyLength == 0 if FCB's extent record u_int32_t hint; // BTree hint corresponding to key HFSPlusExtentRecord extentRecord; u_int32_t extentIndex; u_int32_t extentNextBlock; u_int32_t numExtentsPerRecord; int64_t temp64; u_int8_t 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 (rsrc) { forkType = kResourceForkType; } else { forkType = kDataForkType; } temp64 = fcb->ff_blocks; physNumBlocks = (u_int32_t)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 = howmany(peof, vcb->blockSize); // number of allocation blocks to remain in file peof = (int64_t)((int64_t)nextBlock * (int64_t)vcb->blockSize); // number of bytes in those blocks #if CONFIG_HFS_STD if ((vcb->vcbSigWord == kHFSSigWord) && (peof >= kTwoGigabytes)) { #if DEBUG_BUILD DebugStr("HFS: Trying to truncate a file to 2GB or more"); #endif err = fileBoundsErr; goto ErrorExit; } #endif // // Update FCB's length // /* * XXX Any errors could cause ff_blocks and c_blocks to get out of sync... */ numBlocks = peof / vcb->blockSize; if (!deleted) { FTOC(fcb)->c_blocks -= (fcb->ff_blocks - numBlocks); } fcb->ff_blocks = numBlocks; // this catalog entry is modified and *must* get forced // to disk when hfs_update() is called if (!deleted) { /* * If the file is already C_NOEXISTS, then the catalog record * has been removed from disk already. We wouldn't need to force * another update */ FTOC(fcb)->c_flag |= (C_MODIFIED | C_FORCEUPDATE); } // // 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, 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, 0); 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, 0); 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, deleted, &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, fileid, nextBlock, &recordDeleted); Done: ErrorExit: if (recordDeleted) (void) FlushExtentFile(vcb); return err; } /* * HFS Plus only * */ OSErr HeadTruncateFile ( ExtendedVCB *vcb, FCB *fcb, u_int32_t headblks) { HFSPlusExtentRecord extents; HFSPlusExtentRecord tailExtents; HFSCatalogNodeID fileID; u_int8_t forkType; u_int32_t blkcnt; u_int32_t startblk; u_int32_t blksfreed; int i, j; int error = 0; int lockflags; if (vcb->vcbSigWord != kHFSPlusSigWord) return (-1); forkType = FORK_IS_RSRC(fcb) ? kResourceForkType : kDataForkType; fileID = FTOC(fcb)->c_fileid; bzero(tailExtents, sizeof(tailExtents)); blksfreed = 0; startblk = 0; /* * Process catalog resident extents */ for (i = 0, j = 0; i < kHFSPlusExtentDensity; ++i) { blkcnt = fcb->fcbExtents[i].blockCount; if (blkcnt == 0) break; /* end of extents */ if (blksfreed < headblks) { error = BlockDeallocate(vcb, fcb->fcbExtents[i].startBlock, blkcnt, 0); /* * Any errors after the first BlockDeallocate * must be ignored so we can put the file in * a known state. */ if (error ) { if (i == 0) goto ErrorExit; /* uh oh */ else { error = 0; printf("hfs: HeadTruncateFile: problems deallocating %s (%d)\n", FTOC(fcb)->c_desc.cd_nameptr ? (const char *)FTOC(fcb)->c_desc.cd_nameptr : "", error); } } blksfreed += blkcnt; fcb->fcbExtents[i].startBlock = 0; fcb->fcbExtents[i].blockCount = 0; } else { tailExtents[j].startBlock = fcb->fcbExtents[i].startBlock; tailExtents[j].blockCount = blkcnt; ++j; } startblk += blkcnt; } if (blkcnt == 0) goto CopyExtents; lockflags = hfs_systemfile_lock(vcb, SFL_EXTENTS, HFS_EXCLUSIVE_LOCK); /* * Process overflow extents */ for (;;) { u_int32_t extblks; error = FindExtentRecord(vcb, forkType, fileID, startblk, false, NULL, extents, NULL); if (error) { /* * Any errors after the first BlockDeallocate * must be ignored so we can put the file in * a known state. */ if (error != btNotFound) printf("hfs: HeadTruncateFile: problems finding extents %s (%d)\n", FTOC(fcb)->c_desc.cd_nameptr ? (const char *)FTOC(fcb)->c_desc.cd_nameptr : "", error); error = 0; break; } for(i = 0, extblks = 0; i < kHFSPlusExtentDensity; ++i) { blkcnt = extents[i].blockCount; if (blkcnt == 0) break; /* end of extents */ if (blksfreed < headblks) { error = BlockDeallocate(vcb, extents[i].startBlock, blkcnt, 0); if (error) { printf("hfs: HeadTruncateFile: problems deallocating %s (%d)\n", FTOC(fcb)->c_desc.cd_nameptr ? (const char *)FTOC(fcb)->c_desc.cd_nameptr : "", error); error = 0; } blksfreed += blkcnt; } else { tailExtents[j].startBlock = extents[i].startBlock; tailExtents[j].blockCount = blkcnt; ++j; } extblks += blkcnt; } error = DeleteExtentRecord(vcb, forkType, fileID, startblk); if (error) { printf("hfs: HeadTruncateFile: problems deallocating %s (%d)\n", FTOC(fcb)->c_desc.cd_nameptr ? (const char *)FTOC(fcb)->c_desc.cd_nameptr : "", error); error = 0; } if (blkcnt == 0) break; /* all done */ startblk += extblks; } hfs_systemfile_unlock(vcb, lockflags); CopyExtents: if (blksfreed) { bcopy(tailExtents, fcb->fcbExtents, sizeof(tailExtents)); blkcnt = fcb->ff_blocks - headblks; FTOC(fcb)->c_blocks -= headblks; fcb->ff_blocks = blkcnt; FTOC(fcb)->c_flag |= C_FORCEUPDATE; FTOC(fcb)->c_touch_chgtime = TRUE; (void) FlushExtentFile(vcb); } ErrorExit: return MacToVFSError(error); } //‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹ // 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( ExtendedVCB *vcb, u_int32_t searchFABN, const HFSPlusExtentRecord extentData, u_int32_t extentDataStartFABN, u_int32_t *foundExtentIndex, u_int32_t *endingFABNPlusOne, Boolean *noMoreExtents) { OSErr err = noErr; u_int32_t extentIndex; /* Set it to the HFS std value */ u_int32_t numberOfExtents = kHFSExtentDensity; u_int32_t numAllocationBlocks; Boolean foundExtent; *endingFABNPlusOne = extentDataStartFABN; *noMoreExtents = false; foundExtent = false; /* Override numberOfExtents for HFS+/HFSX */ if (vcb->vcbSigWord != kHFSSigWord) { numberOfExtents = kHFSPlusExtentDensity; } 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( ExtendedVCB *vcb, const FCB *fcb, int64_t filePosition, HFSPlusExtentKey *foundExtentKey, HFSPlusExtentRecord foundExtentData, u_int32_t *foundExtentIndex, u_int32_t *extentBTreeHint, u_int32_t *endingFABNPlusOne ) { OSErr err; u_int32_t filePositionBlock; int64_t temp64; Boolean noMoreExtents; int lockflags; temp64 = filePosition / (int64_t)vcb->blockSize; filePositionBlock = (u_int32_t)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 // lockflags = hfs_systemfile_lock(vcb, SFL_EXTENTS, HFS_EXCLUSIVE_LOCK); err = FindExtentRecord(vcb, FORK_IS_RSRC(fcb) ? kResourceForkType : kDataForkType, FTOC(fcb)->c_fileid, filePositionBlock, true, foundExtentKey, foundExtentData, extentBTreeHint); hfs_systemfile_unlock(vcb, lockflags); 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 // deleted - whether or not the file is already deleted // 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 (ExtendedVCB *vcb, FCB *fcb, int deleted, const HFSPlusExtentKey *extentFileKey, const HFSPlusExtentRecord extentData, u_int32_t extentBTreeHint) { OSErr err = noErr; if (extentFileKey->keyLength == 0) { // keyLength == 0 means the FCB's extent record BlockMoveData(extentData, fcb->fcbExtents, sizeof(HFSPlusExtentRecord)); if (!deleted) { FTOC(fcb)->c_flag |= C_MODIFIED; } } else { struct BTreeIterator *btIterator = NULL; FSBufferDescriptor btRecord; u_int16_t btRecordSize; FCB * btFCB; int lockflags; // // Need to find and change a record in Extents BTree // btFCB = GetFileControlBlock(vcb->extentsRefNum); MALLOC (btIterator, struct BTreeIterator*, sizeof(struct BTreeIterator), M_TEMP, M_WAITOK); if (btIterator == NULL) { return memFullErr; // translates to ENOMEM } bzero(btIterator, sizeof(*btIterator)); /* * The lock taken by callers of ExtendFileC/TruncateFileC is * speculative and only occurs when the file already has * overflow extents. So we need to make sure we have the lock * here. The extents btree lock can be nested (its recursive) * so we always take it here. */ lockflags = hfs_systemfile_lock(vcb, SFL_EXTENTS, HFS_EXCLUSIVE_LOCK); /* HFS+/HFSX */ if (vcb->vcbSigWord != kHFSSigWord) { // 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); } #if CONFIG_HFS_STD else { /* HFS Standard */ 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); } #endif hfs_systemfile_unlock(vcb, lockflags); FREE(btIterator, M_TEMP); } return err; } #if CONFIG_HFS_STD static 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("ExtentRecord with > 3 extents is invalid for HFS"); err = fsDSIntErr; } #endif return err; } #endif static 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, u_int32_t mask, u_int32_t *blocksChecked, Boolean *checkedLastExtent) { u_int32_t blocks; u_int32_t 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, u_int32_t nodeSize) { u_int32_t mask; u_int32_t startBlock; u_int32_t blocksChecked; u_int32_t hint; HFSPlusExtentKey key; HFSPlusExtentRecord extents; OSErr result; Boolean lastExtentReached; int lockflags; 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 || (int64_t)((int64_t)blocksChecked * (int64_t)vcb->blockSize) >= (int64_t)fcb->ff_size) return TRUE; startBlock = blocksChecked; lockflags = hfs_systemfile_lock(vcb, SFL_EXTENTS, HFS_EXCLUSIVE_LOCK); // 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) ) { hfs_systemfile_unlock(vcb, lockflags); return FALSE; } startBlock += blocksChecked; } hfs_systemfile_unlock(vcb, lockflags); return TRUE; }