| /* ----> DO NOT REMOVE THE FOLLOWING NOTICE <---- | |
| Copyright (c) 2014-2015 Datalight, Inc. | |
| All Rights Reserved Worldwide. | |
| This program is free software; you can redistribute it and/or modify | |
| it under the terms of the GNU General Public License as published by | |
| the Free Software Foundation; use version 2 of the License. | |
| This program is distributed in the hope that it will be useful, | |
| but "AS-IS," WITHOUT ANY WARRANTY; without even the implied warranty | |
| of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| GNU General Public License for more details. | |
| You should have received a copy of the GNU General Public License along | |
| with this program; if not, write to the Free Software Foundation, Inc., | |
| 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
| */ | |
| /* Businesses and individuals that for commercial or other reasons cannot | |
| comply with the terms of the GPLv2 license may obtain a commercial license | |
| before incorporating Reliance Edge into proprietary software for | |
| distribution in any form. Visit http://www.datalight.com/reliance-edge for | |
| more information. | |
| */ | |
| /** @file | |
| @brief Implements core volume operations. | |
| */ | |
| #include <redfs.h> | |
| #include <redcore.h> | |
| static bool MetarootIsValid(METAROOT *pMR, bool *pfSectorCRCIsValid); | |
| #ifdef REDCONF_ENDIAN_SWAP | |
| static void MetaRootEndianSwap(METAROOT *pMetaRoot); | |
| #endif | |
| /** @brief Mount a file system volume. | |
| @return A negated ::REDSTATUS code indicating the operation result. | |
| @retval 0 Operation was successful. | |
| @retval -RED_EIO Volume not formatted, improperly formatted, or corrupt. | |
| */ | |
| REDSTATUS RedVolMount(void) | |
| { | |
| REDSTATUS ret; | |
| #if REDCONF_READ_ONLY == 0 | |
| ret = RedOsBDevOpen(gbRedVolNum, BDEV_O_RDWR); | |
| #else | |
| ret = RedOsBDevOpen(gbRedVolNum, BDEV_O_RDONLY); | |
| #endif | |
| if(ret == 0) | |
| { | |
| ret = RedVolMountMaster(); | |
| if(ret == 0) | |
| { | |
| ret = RedVolMountMetaroot(); | |
| } | |
| if(ret != 0) | |
| { | |
| /* If we fail to mount, invalidate the buffers to prevent any | |
| confusion that could be caused by stale or corrupt metadata. | |
| */ | |
| (void)RedBufferDiscardRange(0U, gpRedVolume->ulBlockCount); | |
| (void)RedOsBDevClose(gbRedVolNum); | |
| } | |
| } | |
| return ret; | |
| } | |
| /** @brief Mount the master block. | |
| @return A negated ::REDSTATUS code indicating the operation result. | |
| @retval 0 Operation was successful. | |
| @retval -RED_EIO Master block missing, corrupt, or inconsistent with the | |
| compile-time driver settings. | |
| */ | |
| REDSTATUS RedVolMountMaster(void) | |
| { | |
| REDSTATUS ret; | |
| MASTERBLOCK *pMB; | |
| /* Read the master block, to ensure that the disk was formatted with | |
| Reliance Edge. | |
| */ | |
| ret = RedBufferGet(BLOCK_NUM_MASTER, BFLAG_META_MASTER, CAST_VOID_PTR_PTR(&pMB)); | |
| if(ret == 0) | |
| { | |
| /* Verify that the driver was compiled with the same settings that | |
| the disk was formatted with. If not, the user has made a | |
| mistake: either the driver settings are wrong, or the disk needs | |
| to be reformatted. | |
| */ | |
| if( (pMB->ulVersion != RED_DISK_LAYOUT_VERSION) | |
| || (pMB->ulInodeCount != gpRedVolConf->ulInodeCount) | |
| || (pMB->ulBlockCount != gpRedVolume->ulBlockCount) | |
| || (pMB->uMaxNameLen != REDCONF_NAME_MAX) | |
| || (pMB->uDirectPointers != REDCONF_DIRECT_POINTERS) | |
| || (pMB->uIndirectPointers != REDCONF_INDIRECT_POINTERS) | |
| || (pMB->bBlockSizeP2 != BLOCK_SIZE_P2) | |
| || (((pMB->bFlags & MBFLAG_API_POSIX) != 0U) != (REDCONF_API_POSIX == 1)) | |
| || (((pMB->bFlags & MBFLAG_INODE_TIMESTAMPS) != 0U) != (REDCONF_INODE_TIMESTAMPS == 1)) | |
| || (((pMB->bFlags & MBFLAG_INODE_BLOCKS) != 0U) != (REDCONF_INODE_BLOCKS == 1))) | |
| { | |
| ret = -RED_EIO; | |
| } | |
| #if REDCONF_API_POSIX == 1 | |
| else if(((pMB->bFlags & MBFLAG_INODE_NLINK) != 0U) != (REDCONF_API_POSIX_LINK == 1)) | |
| { | |
| ret = -RED_EIO; | |
| } | |
| #else | |
| else if((pMB->bFlags & MBFLAG_INODE_NLINK) != 0U) | |
| { | |
| ret = -RED_EIO; | |
| } | |
| #endif | |
| else | |
| { | |
| /* Master block configuration is valid. | |
| Save the sequence number of the master block in the volume, | |
| since we need it later (see RedVolMountMetaroot()) and we do | |
| not want to re-buffer the master block. | |
| */ | |
| gpRedVolume->ullSequence = pMB->hdr.ullSequence; | |
| } | |
| RedBufferPut(pMB); | |
| } | |
| return ret; | |
| } | |
| /** @brief Mount the latest metaroot. | |
| This function also populates the volume contexts. | |
| @return A negated ::REDSTATUS code indicating the operation result. | |
| @retval 0 Operation was successful. | |
| @retval -RED_EIO Both metaroots are missing or corrupt. | |
| */ | |
| REDSTATUS RedVolMountMetaroot(void) | |
| { | |
| REDSTATUS ret; | |
| ret = RedIoRead(gbRedVolNum, BLOCK_NUM_FIRST_METAROOT, 1U, &gpRedCoreVol->aMR[0U]); | |
| if(ret == 0) | |
| { | |
| ret = RedIoRead(gbRedVolNum, BLOCK_NUM_FIRST_METAROOT + 1U, 1U, &gpRedCoreVol->aMR[1U]); | |
| } | |
| /* Determine which metaroot is the most recent copy that was written | |
| completely. | |
| */ | |
| if(ret == 0) | |
| { | |
| uint8_t bMR = UINT8_MAX; | |
| bool fSectorCRCIsValid; | |
| if(MetarootIsValid(&gpRedCoreVol->aMR[0U], &fSectorCRCIsValid)) | |
| { | |
| bMR = 0U; | |
| #ifdef REDCONF_ENDIAN_SWAP | |
| MetaRootEndianSwap(&gpRedCoreVol->aMR[0U]); | |
| #endif | |
| } | |
| else if(gpRedVolConf->fAtomicSectorWrite && !fSectorCRCIsValid) | |
| { | |
| ret = -RED_EIO; | |
| } | |
| else | |
| { | |
| /* Metaroot is not valid, so it is ignored and there's nothing | |
| to do here. | |
| */ | |
| } | |
| if(ret == 0) | |
| { | |
| if(MetarootIsValid(&gpRedCoreVol->aMR[1U], &fSectorCRCIsValid)) | |
| { | |
| #ifdef REDCONF_ENDIAN_SWAP | |
| MetaRootEndianSwap(&gpRedCoreVol->aMR[1U]); | |
| #endif | |
| if((bMR != 0U) || (gpRedCoreVol->aMR[1U].hdr.ullSequence > gpRedCoreVol->aMR[0U].hdr.ullSequence)) | |
| { | |
| bMR = 1U; | |
| } | |
| } | |
| else if(gpRedVolConf->fAtomicSectorWrite && !fSectorCRCIsValid) | |
| { | |
| ret = -RED_EIO; | |
| } | |
| else | |
| { | |
| /* Metaroot is not valid, so it is ignored and there's nothing | |
| to do here. | |
| */ | |
| } | |
| } | |
| if(ret == 0) | |
| { | |
| if(bMR == UINT8_MAX) | |
| { | |
| /* Neither metaroot was valid. | |
| */ | |
| ret = -RED_EIO; | |
| } | |
| else | |
| { | |
| gpRedCoreVol->bCurMR = bMR; | |
| gpRedMR = &gpRedCoreVol->aMR[bMR]; | |
| } | |
| } | |
| } | |
| if(ret == 0) | |
| { | |
| /* Normally the metaroot contains the highest sequence number, but the | |
| master block is the last block written during format, so on a | |
| freshly formatted volume the master block sequence number (stored in | |
| gpRedVolume->ullSequence) will be higher than that in the metaroot. | |
| */ | |
| if(gpRedMR->hdr.ullSequence > gpRedVolume->ullSequence) | |
| { | |
| gpRedVolume->ullSequence = gpRedMR->hdr.ullSequence; | |
| } | |
| /* gpRedVolume->ullSequence stores the *next* sequence number; to avoid | |
| giving the next node written to disk the same sequence number as the | |
| metaroot, increment it here. | |
| */ | |
| ret = RedVolSeqNumIncrement(); | |
| } | |
| if(ret == 0) | |
| { | |
| gpRedVolume->fMounted = true; | |
| #if REDCONF_READ_ONLY == 0 | |
| gpRedVolume->fReadOnly = false; | |
| #endif | |
| #if RESERVED_BLOCKS > 0U | |
| gpRedCoreVol->fUseReservedBlocks = false; | |
| #endif | |
| gpRedCoreVol->ulAlmostFreeBlocks = 0U; | |
| gpRedCoreVol->aMR[1U - gpRedCoreVol->bCurMR] = *gpRedMR; | |
| gpRedCoreVol->bCurMR = 1U - gpRedCoreVol->bCurMR; | |
| gpRedMR = &gpRedCoreVol->aMR[gpRedCoreVol->bCurMR]; | |
| } | |
| return ret; | |
| } | |
| /** @brief Determine whether the metaroot is valid. | |
| @param pMR The metaroot buffer. | |
| @param pfSectorCRCIsValid Populated with whether the first sector of the | |
| metaroot buffer is valid. | |
| @return Whether the metaroot is valid. | |
| @retval true The metaroot buffer is valid. | |
| @retval false The metaroot buffer is invalid. | |
| */ | |
| static bool MetarootIsValid( | |
| METAROOT *pMR, | |
| bool *pfSectorCRCIsValid) | |
| { | |
| bool fRet = false; | |
| if(pfSectorCRCIsValid == NULL) | |
| { | |
| REDERROR(); | |
| } | |
| else if(pMR == NULL) | |
| { | |
| REDERROR(); | |
| *pfSectorCRCIsValid = false; | |
| } | |
| #ifdef REDCONF_ENDIAN_SWAP | |
| else if(RedRev32(pMR->hdr.ulSignature) != META_SIG_METAROOT) | |
| #else | |
| else if(pMR->hdr.ulSignature != META_SIG_METAROOT) | |
| #endif | |
| { | |
| *pfSectorCRCIsValid = false; | |
| } | |
| else | |
| { | |
| const uint8_t *pbMR = CAST_VOID_PTR_TO_CONST_UINT8_PTR(pMR); | |
| uint32_t ulSectorCRC = pMR->ulSectorCRC; | |
| uint32_t ulCRC; | |
| #ifdef REDCONF_ENDIAN_SWAP | |
| ulSectorCRC = RedRev32(ulSectorCRC); | |
| #endif | |
| /* The sector CRC was zero when the CRC was computed during the | |
| transaction, so it must be zero here. | |
| */ | |
| pMR->ulSectorCRC = 0U; | |
| ulCRC = RedCrc32Update(0U, &pbMR[8U], gpRedVolConf->ulSectorSize - 8U); | |
| fRet = ulCRC == ulSectorCRC; | |
| *pfSectorCRCIsValid = fRet; | |
| if(fRet) | |
| { | |
| if(gpRedVolConf->ulSectorSize < REDCONF_BLOCK_SIZE) | |
| { | |
| ulCRC = RedCrc32Update(ulCRC, &pbMR[gpRedVolConf->ulSectorSize], REDCONF_BLOCK_SIZE - gpRedVolConf->ulSectorSize); | |
| } | |
| #ifdef REDCONF_ENDIAN_SWAP | |
| ulCRC = RedRev32(ulCRC); | |
| #endif | |
| fRet = ulCRC == pMR->hdr.ulCRC; | |
| } | |
| } | |
| return fRet; | |
| } | |
| #if REDCONF_READ_ONLY == 0 | |
| /** @brief Commit a transaction point. | |
| @return A negated ::REDSTATUS code indicating the operation result. | |
| @retval 0 Operation was successful. | |
| @retval -RED_EIO A disk I/O error occurred. | |
| */ | |
| REDSTATUS RedVolTransact(void) | |
| { | |
| REDSTATUS ret = 0; | |
| REDASSERT(!gpRedVolume->fReadOnly); /* Should be checked by caller. */ | |
| if(gpRedCoreVol->fBranched) | |
| { | |
| gpRedMR->ulFreeBlocks += gpRedCoreVol->ulAlmostFreeBlocks; | |
| gpRedCoreVol->ulAlmostFreeBlocks = 0U; | |
| ret = RedBufferFlush(0U, gpRedVolume->ulBlockCount); | |
| if(ret == 0) | |
| { | |
| gpRedMR->hdr.ulSignature = META_SIG_METAROOT; | |
| gpRedMR->hdr.ullSequence = gpRedVolume->ullSequence; | |
| ret = RedVolSeqNumIncrement(); | |
| } | |
| if(ret == 0) | |
| { | |
| const uint8_t *pbMR = CAST_VOID_PTR_TO_CONST_UINT8_PTR(gpRedMR); | |
| uint32_t ulSectorCRC; | |
| #ifdef REDCONF_ENDIAN_SWAP | |
| MetaRootEndianSwap(gpRedMR); | |
| #endif | |
| gpRedMR->ulSectorCRC = 0U; | |
| ulSectorCRC = RedCrc32Update(0U, &pbMR[8U], gpRedVolConf->ulSectorSize - 8U); | |
| if(gpRedVolConf->ulSectorSize < REDCONF_BLOCK_SIZE) | |
| { | |
| gpRedMR->hdr.ulCRC = RedCrc32Update(ulSectorCRC, &pbMR[gpRedVolConf->ulSectorSize], REDCONF_BLOCK_SIZE - gpRedVolConf->ulSectorSize); | |
| } | |
| else | |
| { | |
| gpRedMR->hdr.ulCRC = ulSectorCRC; | |
| } | |
| gpRedMR->ulSectorCRC = ulSectorCRC; | |
| #ifdef REDCONF_ENDIAN_SWAP | |
| gpRedMR->hdr.ulCRC = RedRev32(gpRedMR->hdr.ulCRC); | |
| gpRedMR->ulSectorCRC = RedRev32(gpRedMR->ulSectorCRC); | |
| #endif | |
| /* Flush the block device before writing the metaroot, so that all | |
| previously written blocks are guaranteed to be on the media before | |
| the metaroot is written. Otherwise, if the block device reorders | |
| the writes, the metaroot could reach the media before metadata it | |
| points at, creating a window for disk corruption if power is lost. | |
| */ | |
| ret = RedIoFlush(gbRedVolNum); | |
| } | |
| if(ret == 0) | |
| { | |
| ret = RedIoWrite(gbRedVolNum, BLOCK_NUM_FIRST_METAROOT + gpRedCoreVol->bCurMR, 1U, gpRedMR); | |
| #ifdef REDCONF_ENDIAN_SWAP | |
| MetaRootEndianSwap(gpRedMR); | |
| #endif | |
| } | |
| /* Flush the block device to force the metaroot write to the media. This | |
| guarantees the transaction point is really complete before we return. | |
| */ | |
| if(ret == 0) | |
| { | |
| ret = RedIoFlush(gbRedVolNum); | |
| } | |
| /* Toggle to the other metaroot buffer. The working state and committed | |
| state metaroot buffers exchange places. | |
| */ | |
| if(ret == 0) | |
| { | |
| uint8_t bNextMR = 1U - gpRedCoreVol->bCurMR; | |
| gpRedCoreVol->aMR[bNextMR] = *gpRedMR; | |
| gpRedCoreVol->bCurMR = bNextMR; | |
| gpRedMR = &gpRedCoreVol->aMR[gpRedCoreVol->bCurMR]; | |
| gpRedCoreVol->fBranched = false; | |
| } | |
| CRITICAL_ASSERT(ret == 0); | |
| } | |
| return ret; | |
| } | |
| #endif | |
| #ifdef REDCONF_ENDIAN_SWAP | |
| static void MetaRootEndianSwap( | |
| METAROOT *pMetaRoot) | |
| { | |
| if(pMetaRoot == NULL) | |
| { | |
| REDERROR(); | |
| } | |
| else | |
| { | |
| pMetaRoot->ulSectorCRC = RedRev32(pMetaRoot->ulSectorCRC); | |
| pMetaRoot->ulFreeBlocks = RedRev32(pMetaRoot->ulFreeBlocks); | |
| #if REDCONF_API_POSIX == 1 | |
| pMetaRoot->ulFreeInodes = RedRev32(pMetaRoot->ulFreeInodes); | |
| #endif | |
| pMetaRoot->ulAllocNextBlock = RedRev32(pMetaRoot->ulAllocNextBlock); | |
| } | |
| } | |
| #endif | |
| /** @brief Process a critical file system error. | |
| @param pszFileName The file in which the error occurred. | |
| @param ulLineNum The line number at which the error occurred. | |
| */ | |
| void RedVolCriticalError( | |
| const char *pszFileName, | |
| uint32_t ulLineNum) | |
| { | |
| #if REDCONF_OUTPUT == 1 | |
| #if REDCONF_READ_ONLY == 0 | |
| if(!gpRedVolume->fReadOnly) | |
| { | |
| RedOsOutputString("Critical file system error in Reliance Edge, setting volume to READONLY\n"); | |
| } | |
| else | |
| #endif | |
| { | |
| RedOsOutputString("Critical file system error in Reliance Edge (volume already READONLY)\n"); | |
| } | |
| #endif | |
| #if REDCONF_READ_ONLY == 0 | |
| gpRedVolume->fReadOnly = true; | |
| #endif | |
| #if REDCONF_ASSERTS == 1 | |
| RedOsAssertFail(pszFileName, ulLineNum); | |
| #else | |
| (void)pszFileName; | |
| (void)ulLineNum; | |
| #endif | |
| } | |
| /** @brief Increment the sequence number. | |
| @return A negated ::REDSTATUS code indicating the operation result. | |
| @retval 0 Operation was successful. | |
| @retval -RED_EINVAL Cannot increment sequence number: maximum value reached. | |
| This should not ever happen. | |
| */ | |
| REDSTATUS RedVolSeqNumIncrement(void) | |
| { | |
| REDSTATUS ret; | |
| if(gpRedVolume->ullSequence == UINT64_MAX) | |
| { | |
| /* In practice this should never, ever happen; to get here, there would | |
| need to be UINT64_MAX disk writes, which would take eons: longer | |
| than the lifetime of any product or storage media. If this assert | |
| fires and the current year is still written with four digits, | |
| suspect memory corruption. | |
| */ | |
| CRITICAL_ERROR(); | |
| ret = -RED_EFUBAR; | |
| } | |
| else | |
| { | |
| gpRedVolume->ullSequence++; | |
| ret = 0; | |
| } | |
| return ret; | |
| } | |