From 979a4695371e76d8b2c3c755ef98c94b03fd2d09 Mon Sep 17 00:00:00 2001 From: "fabio.olimpieri" Date: Sun, 11 Jan 2015 19:58:35 +0000 Subject: [PATCH] Libfat patch to fix FAT_setAttr --- libfat_patch/fatfile.c | 1215 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1215 insertions(+) create mode 100644 libfat_patch/fatfile.c diff --git a/libfat_patch/fatfile.c b/libfat_patch/fatfile.c new file mode 100644 index 0000000..796391c --- /dev/null +++ b/libfat_patch/fatfile.c @@ -0,0 +1,1215 @@ +/* + fatfile.c + + Functions used by the newlib disc stubs to interface with + this library + + Copyright (c) 2006 Michael "Chishm" Chisholm + + Redistribution and use in source and binary forms, with or without modification, + are permitted provided that the following conditions are met: + + 1. Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + 2. Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation and/or + other materials provided with the distribution. + 3. The name of the author may not be used to endorse or promote products derived + from this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY + AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, + EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + 2009-10-23 oggzee: fixes for cluster aligned file size (write, truncate, seek) +*/ + + +#include "fatfile.h" + +#include +#include +#include +#include +#include + +#include "cache.h" +#include "file_allocation_table.h" +#include "bit_ops.h" +#include "filetime.h" +#include "lock.h" + +bool _FAT_findEntry(const char *path, DIR_ENTRY *dirEntry) { + PARTITION *partition = _FAT_partition_getPartitionFromPath(path); + + // Move the path pointer to the start of the actual path + if (strchr (path, ':') != NULL) { + path = strchr (path, ':') + 1; + } + if (strchr (path, ':') != NULL) { + return false; + } + + // Search for the file on the disc + return _FAT_directory_entryFromPath (partition, dirEntry, path, NULL); + +} + +int FAT_getAttr(const char *file) { + DIR_ENTRY dirEntry; + if (!_FAT_findEntry(file,&dirEntry)) return -1; + + return dirEntry.entryData[DIR_ENTRY_attributes]; +} + +int FAT_setAttr(const char *file, int attr) { + + // Defines... + DIR_ENTRY_POSITION entryEnd; + PARTITION *partition = NULL; + DIR_ENTRY* dirEntry = NULL; + + DIR_ENTRY dirEntry_variable; //UAE WII + char attr_byte; //UAE WII + + dirEntry =&dirEntry_variable; //UAE WII + attr_byte= (char) attr; //UAE WII + + // Get Partition + partition = _FAT_partition_getPartitionFromPath( file ); + + // Check Partition + if( !partition ) + return -1; + + // Move the path pointer to the start of the actual path + if (strchr (file, ':') != NULL) + file = strchr (file, ':') + 1; + if (strchr (file, ':') != NULL) + return -1; + + // Get DIR_ENTRY + if( !_FAT_directory_entryFromPath (partition, dirEntry, file, NULL) ) + return -1; + + // Get Entry-End + entryEnd = dirEntry->dataEnd; + + // Lock Partition + _FAT_lock(&partition->lock); + + + // Write Data + _FAT_cache_writePartialSector ( + partition->cache // Cache to write + , &attr_byte // Value to be written UAE WII + , _FAT_fat_clusterToSector( partition , entryEnd.cluster ) + entryEnd.sector // cluster + , entryEnd.offset * DIR_ENTRY_DATA_SIZE + DIR_ENTRY_attributes // offset + , 1 // Size in bytes + ); + + // Flush any sectors in the disc cache + if ( !_FAT_cache_flush( partition->cache ) ) { + _FAT_unlock(&partition->lock); // Unlock Partition + return -1; + } + + // Unlock Partition + _FAT_unlock(&partition->lock); + + return 0; +} + + +int _FAT_open_r (struct _reent *r, void *fileStruct, const char *path, int flags, int mode) { + PARTITION* partition = NULL; + bool fileExists; + DIR_ENTRY dirEntry; + const char* pathEnd; + uint32_t dirCluster; + FILE_STRUCT* file = (FILE_STRUCT*) fileStruct; + partition = _FAT_partition_getPartitionFromPath (path); + + if (partition == NULL) { + r->_errno = ENODEV; + return -1; + } + + // Move the path pointer to the start of the actual path + if (strchr (path, ':') != NULL) { + path = strchr (path, ':') + 1; + } + if (strchr (path, ':') != NULL) { + r->_errno = EINVAL; + return -1; + } + + // Determine which mode the file is openned for + if ((flags & 0x03) == O_RDONLY) { + // Open the file for read-only access + file->read = true; + file->write = false; + file->append = false; + } else if ((flags & 0x03) == O_WRONLY) { + // Open file for write only access + file->read = false; + file->write = true; + file->append = false; + } else if ((flags & 0x03) == O_RDWR) { + // Open file for read/write access + file->read = true; + file->write = true; + file->append = false; + } else { + r->_errno = EACCES; + return -1; + } + + // Make sure we aren't trying to write to a read-only disc + if (file->write && partition->readOnly) { + r->_errno = EROFS; + return -1; + } + + // Search for the file on the disc + _FAT_lock(&partition->lock); + fileExists = _FAT_directory_entryFromPath (partition, &dirEntry, path, NULL); + + // The file shouldn't exist if we are trying to create it + if ((flags & O_CREAT) && (flags & O_EXCL) && fileExists) { + _FAT_unlock(&partition->lock); + r->_errno = EEXIST; + return -1; + } + + // It should not be a directory if we're openning a file, + if (fileExists && _FAT_directory_isDirectory(&dirEntry)) { + _FAT_unlock(&partition->lock); + r->_errno = EISDIR; + return -1; + } + + // We haven't modified the file yet + file->modified = false; + + // If the file doesn't exist, create it if we're allowed to + if (!fileExists) { + if (flags & O_CREAT) { + if (partition->readOnly) { + // We can't write to a read-only partition + _FAT_unlock(&partition->lock); + r->_errno = EROFS; + return -1; + } + // Create the file + // Get the directory it has to go in + pathEnd = strrchr (path, DIR_SEPARATOR); + if (pathEnd == NULL) { + // No path was specified + dirCluster = partition->cwdCluster; + pathEnd = path; + } else { + // Path was specified -- get the right dirCluster + // Recycling dirEntry, since it needs to be recreated anyway + if (!_FAT_directory_entryFromPath (partition, &dirEntry, path, pathEnd) || + !_FAT_directory_isDirectory(&dirEntry)) { + _FAT_unlock(&partition->lock); + r->_errno = ENOTDIR; + return -1; + } + dirCluster = _FAT_directory_entryGetCluster (partition, dirEntry.entryData); + // Move the pathEnd past the last DIR_SEPARATOR + pathEnd += 1; + } + // Create the entry data + strncpy (dirEntry.filename, pathEnd, MAX_FILENAME_LENGTH - 1); + memset (dirEntry.entryData, 0, DIR_ENTRY_DATA_SIZE); + + // Set the creation time and date + dirEntry.entryData[DIR_ENTRY_cTime_ms] = 0; + u16_to_u8array (dirEntry.entryData, DIR_ENTRY_cTime, _FAT_filetime_getTimeFromRTC()); + u16_to_u8array (dirEntry.entryData, DIR_ENTRY_cDate, _FAT_filetime_getDateFromRTC()); + + if (!_FAT_directory_addEntry (partition, &dirEntry, dirCluster)) { + _FAT_unlock(&partition->lock); + r->_errno = ENOSPC; + return -1; + } + + // File entry is modified + file->modified = true; + } else { + // file doesn't exist, and we aren't creating it + _FAT_unlock(&partition->lock); + r->_errno = ENOENT; + return -1; + } + } + + file->filesize = u8array_to_u32 (dirEntry.entryData, DIR_ENTRY_fileSize); + + /* Allow LARGEFILEs with undefined results + // Make sure that the file size can fit in the available space + if (!(flags & O_LARGEFILE) && (file->filesize >= (1<<31))) { + r->_errno = EFBIG; + return -1; + } + */ + + // Make sure we aren't trying to write to a read-only file + if (file->write && !_FAT_directory_isWritable(&dirEntry)) { + _FAT_unlock(&partition->lock); + r->_errno = EROFS; + return -1; + } + + // Associate this file with a particular partition + file->partition = partition; + + file->startCluster = _FAT_directory_entryGetCluster (partition, dirEntry.entryData); + + // Truncate the file if requested + if ((flags & O_TRUNC) && file->write && (file->startCluster != 0)) { + _FAT_fat_clearLinks (partition, file->startCluster); + file->startCluster = CLUSTER_FREE; + file->filesize = 0; + // File is modified since we just cut it all off + file->modified = true; + } + + // Remember the position of this file's directory entry + file->dirEntryStart = dirEntry.dataStart; // Points to the start of the LFN entries of a file, or the alias for no LFN + file->dirEntryEnd = dirEntry.dataEnd; + + // Reset read/write pointer + file->currentPosition = 0; + file->rwPosition.cluster = file->startCluster; + file->rwPosition.sector = 0; + file->rwPosition.byte = 0; + + if (flags & O_APPEND) { + file->append = true; + + // Set append pointer to the end of the file + file->appendPosition.cluster = _FAT_fat_lastCluster (partition, file->startCluster); + file->appendPosition.sector = (file->filesize % partition->bytesPerCluster) / partition->bytesPerSector; + file->appendPosition.byte = file->filesize % partition->bytesPerSector; + + // Check if the end of the file is on the end of a cluster + if ( (file->filesize > 0) && ((file->filesize % partition->bytesPerCluster)==0) ){ + // Set flag to allocate a new cluster + file->appendPosition.sector = partition->sectorsPerCluster; + file->appendPosition.byte = 0; + } + } else { + file->append = false; + // Use something sane for the append pointer, so the whole file struct contains known values + file->appendPosition = file->rwPosition; + } + + file->inUse = true; + + // Insert this file into the double-linked list of open files + partition->openFileCount += 1; + if (partition->firstOpenFile) { + file->nextOpenFile = partition->firstOpenFile; + partition->firstOpenFile->prevOpenFile = file; + } else { + file->nextOpenFile = NULL; + } + file->prevOpenFile = NULL; + partition->firstOpenFile = file; + + _FAT_unlock(&partition->lock); + + return (int) file; +} + +/* +Synchronizes the file data to disc. +Does no locking of its own -- lock the partition before calling. +Returns 0 on success, an error code on failure. +*/ +int _FAT_syncToDisc (FILE_STRUCT* file) { + uint8_t dirEntryData[DIR_ENTRY_DATA_SIZE]; + + if (!file || !file->inUse) { + return EBADF; + } + + if (file->write && file->modified) { + // Load the old entry + _FAT_cache_readPartialSector (file->partition->cache, dirEntryData, + _FAT_fat_clusterToSector(file->partition, file->dirEntryEnd.cluster) + file->dirEntryEnd.sector, + file->dirEntryEnd.offset * DIR_ENTRY_DATA_SIZE, DIR_ENTRY_DATA_SIZE); + + // Write new data to the directory entry + // File size + u32_to_u8array (dirEntryData, DIR_ENTRY_fileSize, file->filesize); + + // Start cluster + u16_to_u8array (dirEntryData, DIR_ENTRY_cluster, file->startCluster); + u16_to_u8array (dirEntryData, DIR_ENTRY_clusterHigh, file->startCluster >> 16); + + // Modification time and date + u16_to_u8array (dirEntryData, DIR_ENTRY_mTime, _FAT_filetime_getTimeFromRTC()); + u16_to_u8array (dirEntryData, DIR_ENTRY_mDate, _FAT_filetime_getDateFromRTC()); + + // Access date + u16_to_u8array (dirEntryData, DIR_ENTRY_aDate, _FAT_filetime_getDateFromRTC()); + + // Set archive attribute + dirEntryData[DIR_ENTRY_attributes] |= ATTRIB_ARCH; + + // Write the new entry + _FAT_cache_writePartialSector (file->partition->cache, dirEntryData, + _FAT_fat_clusterToSector(file->partition, file->dirEntryEnd.cluster) + file->dirEntryEnd.sector, + file->dirEntryEnd.offset * DIR_ENTRY_DATA_SIZE, DIR_ENTRY_DATA_SIZE); + + // Flush any sectors in the disc cache + if (!_FAT_cache_flush(file->partition->cache)) { + return EIO; + } + } + + file->modified = false; + + return 0; +} + + +int _FAT_close_r (struct _reent *r, int fd) { + FILE_STRUCT* file = (FILE_STRUCT*) fd; + int ret = 0; + + if (!file->inUse) { + r->_errno = EBADF; + return -1; + } + + _FAT_lock(&file->partition->lock); + + if (file->write) { + ret = _FAT_syncToDisc (file); + if (ret != 0) { + r->_errno = ret; + ret = -1; + } + } + + file->inUse = false; + + // Remove this file from the double-linked list of open files + file->partition->openFileCount -= 1; + if (file->nextOpenFile) { + file->nextOpenFile->prevOpenFile = file->prevOpenFile; + } + if (file->prevOpenFile) { + file->prevOpenFile->nextOpenFile = file->nextOpenFile; + } else { + file->partition->firstOpenFile = file->nextOpenFile; + } + + _FAT_unlock(&file->partition->lock); + + return ret; +} + +ssize_t _FAT_read_r (struct _reent *r, int fd, char *ptr, size_t len) { + FILE_STRUCT* file = (FILE_STRUCT*) fd; + PARTITION* partition; + CACHE* cache; + FILE_POSITION position; + uint32_t tempNextCluster; + unsigned int tempVar; + size_t remain; + bool flagNoError = true; + + // Short circuit cases where len is 0 (or less) + if (len <= 0) { + return 0; + } + + // Make sure we can actually read from the file + if ((file == NULL) || !file->inUse || !file->read) { + r->_errno = EBADF; + return -1; + } + + partition = file->partition; + _FAT_lock(&partition->lock); + + // Don't try to read if the read pointer is past the end of file + if (file->currentPosition >= file->filesize || file->startCluster == CLUSTER_FREE) { + r->_errno = EOVERFLOW; + _FAT_unlock(&partition->lock); + return 0; + } + + // Don't read past end of file + if (len + file->currentPosition > file->filesize) { + r->_errno = EOVERFLOW; + len = file->filesize - file->currentPosition; + } + + remain = len; + position = file->rwPosition; + cache = file->partition->cache; + + // Align to sector + tempVar = partition->bytesPerSector - position.byte; + if (tempVar > remain) { + tempVar = remain; + } + + if ((tempVar < partition->bytesPerSector) && flagNoError) + { + _FAT_cache_readPartialSector ( cache, ptr, _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, + position.byte, tempVar); + + remain -= tempVar; + ptr += tempVar; + + position.byte += tempVar; + if (position.byte >= partition->bytesPerSector) { + position.byte = 0; + position.sector++; + } + } + + // align to cluster + // tempVar is number of sectors to read + if (remain > (partition->sectorsPerCluster - position.sector) * partition->bytesPerSector) { + tempVar = partition->sectorsPerCluster - position.sector; + } else { + tempVar = remain / partition->bytesPerSector; + } + + if ((tempVar > 0) && flagNoError) { + if (! _FAT_cache_readSectors (cache, _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, + tempVar, ptr)) + { + flagNoError = false; + r->_errno = EIO; + } else { + ptr += tempVar * partition->bytesPerSector; + remain -= tempVar * partition->bytesPerSector; + position.sector += tempVar; + } + } + + // Move onto next cluster + // It should get to here without reading anything if a cluster is due to be allocated + if ((position.sector >= partition->sectorsPerCluster) && flagNoError) { + tempNextCluster = _FAT_fat_nextCluster(partition, position.cluster); + if ((remain == 0) && (tempNextCluster == CLUSTER_EOF)) { + position.sector = partition->sectorsPerCluster; + } else if (!_FAT_fat_isValidCluster(partition, tempNextCluster)) { + r->_errno = EIO; + flagNoError = false; + } else { + position.sector = 0; + position.cluster = tempNextCluster; + } + } + + // Read in whole clusters, contiguous blocks at a time + while ((remain >= partition->bytesPerCluster) && flagNoError) { + uint32_t chunkEnd; + uint32_t nextChunkStart = position.cluster; + size_t chunkSize = 0; + + do { + chunkEnd = nextChunkStart; + nextChunkStart = _FAT_fat_nextCluster (partition, chunkEnd); + chunkSize += partition->bytesPerCluster; + } while ((nextChunkStart == chunkEnd + 1) && +#ifdef LIMIT_SECTORS + (chunkSize + partition->bytesPerCluster <= LIMIT_SECTORS * partition->bytesPerSector) && +#endif + (chunkSize + partition->bytesPerCluster <= remain)); + + if (!_FAT_cache_readSectors (cache, _FAT_fat_clusterToSector (partition, position.cluster), + chunkSize / partition->bytesPerSector, ptr)) + { + flagNoError = false; + r->_errno = EIO; + break; + } + ptr += chunkSize; + remain -= chunkSize; + + // Advance to next cluster + if ((remain == 0) && (nextChunkStart == CLUSTER_EOF)) { + position.sector = partition->sectorsPerCluster; + position.cluster = chunkEnd; + } else if (!_FAT_fat_isValidCluster(partition, nextChunkStart)) { + r->_errno = EIO; + flagNoError = false; + } else { + position.sector = 0; + position.cluster = nextChunkStart; + } + } + + // Read remaining sectors + tempVar = remain / partition->bytesPerSector; // Number of sectors left + if ((tempVar > 0) && flagNoError) { + if (!_FAT_cache_readSectors (cache, _FAT_fat_clusterToSector (partition, position.cluster), + tempVar, ptr)) + { + flagNoError = false; + r->_errno = EIO; + } else { + ptr += tempVar * partition->bytesPerSector; + remain -= tempVar * partition->bytesPerSector; + position.sector += tempVar; + } + } + + // Last remaining sector + // Check if anything is left + if ((remain > 0) && flagNoError) { + _FAT_cache_readPartialSector ( cache, ptr, + _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, 0, remain); + position.byte += remain; + remain = 0; + } + + // Length read is the wanted length minus the stuff not read + len = len - remain; + + // Update file information + file->rwPosition = position; + file->currentPosition += len; + + _FAT_unlock(&partition->lock); + return len; +} + +// if current position is on the cluster border and more data has to be written +// then get next cluster or allocate next cluster +// this solves the over-allocation problems when file size is aligned to cluster size +// return true on succes, false on error +static bool _FAT_check_position_for_next_cluster(struct _reent *r, + FILE_POSITION *position, PARTITION* partition, size_t remain, bool *flagNoError) +{ + uint32_t tempNextCluster; + // do nothing if no more data to write + if (remain == 0) return true; + if (flagNoError && *flagNoError == false) return false; + if ((remain < 0) || (position->sector > partition->sectorsPerCluster)) { + // invalid arguments - internal error + r->_errno = EINVAL; + goto err; + } + if (position->sector == partition->sectorsPerCluster) { + // need to advance to next cluster + tempNextCluster = _FAT_fat_nextCluster(partition, position->cluster); + if ((tempNextCluster == CLUSTER_EOF) || (tempNextCluster == CLUSTER_FREE)) { + // Ran out of clusters so get a new one + tempNextCluster = _FAT_fat_linkFreeCluster(partition, position->cluster); + } + if (!_FAT_fat_isValidCluster(partition, tempNextCluster)) { + // Couldn't get a cluster, so abort + r->_errno = ENOSPC; + goto err; + } + position->sector = 0; + position->cluster = tempNextCluster; + } + return true; +err: + if (flagNoError) *flagNoError = false; + return false; +} + +/* +Extend a file so that the size is the same as the rwPosition +*/ +static bool _FAT_file_extend_r (struct _reent *r, FILE_STRUCT* file) { + PARTITION* partition = file->partition; + CACHE* cache = file->partition->cache; + FILE_POSITION position; + uint8_t zeroBuffer [partition->bytesPerSector]; + memset(zeroBuffer, 0, partition->bytesPerSector); + uint32_t remain; + uint32_t tempNextCluster; + unsigned int sector; + + position.byte = file->filesize % partition->bytesPerSector; + position.sector = (file->filesize % partition->bytesPerCluster) / partition->bytesPerSector; + // It is assumed that there is always a startCluster + // This will be true when _FAT_file_extend_r is called from _FAT_write_r + position.cluster = _FAT_fat_lastCluster (partition, file->startCluster); + + remain = file->currentPosition - file->filesize; + + if ((remain > 0) && (file->filesize > 0) && (position.sector == 0) && (position.byte == 0)) { + // Get a new cluster on the edge of a cluster boundary + tempNextCluster = _FAT_fat_linkFreeCluster(partition, position.cluster); + if (!_FAT_fat_isValidCluster(partition, tempNextCluster)) { + // Couldn't get a cluster, so abort + r->_errno = ENOSPC; + return false; + } + position.cluster = tempNextCluster; + position.sector = 0; + } + + if (remain + position.byte < partition->bytesPerSector) { + // Only need to clear to the end of the sector + _FAT_cache_writePartialSector (cache, zeroBuffer, + _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, position.byte, remain); + position.byte += remain; + } else { + if (position.byte > 0) { + _FAT_cache_writePartialSector (cache, zeroBuffer, + _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, position.byte, + partition->bytesPerSector - position.byte); + remain -= (partition->bytesPerSector - position.byte); + position.byte = 0; + position.sector ++; + } + + while (remain >= partition->bytesPerSector) { + if (position.sector >= partition->sectorsPerCluster) { + position.sector = 0; + // Ran out of clusters so get a new one + tempNextCluster = _FAT_fat_linkFreeCluster(partition, position.cluster); + if (!_FAT_fat_isValidCluster(partition, tempNextCluster)) { + // Couldn't get a cluster, so abort + r->_errno = ENOSPC; + return false; + } + position.cluster = tempNextCluster; + } + + sector = _FAT_fat_clusterToSector (partition, position.cluster) + position.sector; + _FAT_cache_writeSectors (cache, sector, 1, zeroBuffer); + + remain -= partition->bytesPerSector; + position.sector ++; + } + + if (!_FAT_check_position_for_next_cluster(r, &position, partition, remain, NULL)) { + // error already marked + return false; + } + + if (remain > 0) { + _FAT_cache_writePartialSector (cache, zeroBuffer, + _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, 0, remain); + position.byte = remain; + } + } + + file->rwPosition = position; + file->filesize = file->currentPosition; + return true; +} + +ssize_t _FAT_write_r (struct _reent *r, int fd, const char *ptr, size_t len) { + FILE_STRUCT* file = (FILE_STRUCT*) fd; + PARTITION* partition; + CACHE* cache; + FILE_POSITION position; + uint32_t tempNextCluster; + unsigned int tempVar; + size_t remain; + bool flagNoError = true; + bool flagAppending = false; + + // Make sure we can actually write to the file + if ((file == NULL) || !file->inUse || !file->write) { + r->_errno = EBADF; + return -1; + } + + partition = file->partition; + cache = file->partition->cache; + _FAT_lock(&partition->lock); + + // Only write up to the maximum file size, taking into account wrap-around of ints + if (len + file->filesize > FILE_MAX_SIZE || len + file->filesize < file->filesize) { + len = FILE_MAX_SIZE - file->filesize; + } + + // Short circuit cases where len is 0 (or less) + if (len <= 0) { + _FAT_unlock(&partition->lock); + return 0; + } + + remain = len; + + // Get a new cluster for the start of the file if required + if (file->startCluster == CLUSTER_FREE) { + tempNextCluster = _FAT_fat_linkFreeCluster (partition, CLUSTER_FREE); + if (!_FAT_fat_isValidCluster(partition, tempNextCluster)) { + // Couldn't get a cluster, so abort immediately + _FAT_unlock(&partition->lock); + r->_errno = ENOSPC; + return -1; + } + file->startCluster = tempNextCluster; + + // Appending starts at the begining for a 0 byte file + file->appendPosition.cluster = file->startCluster; + file->appendPosition.sector = 0; + file->appendPosition.byte = 0; + + file->rwPosition.cluster = file->startCluster; + file->rwPosition.sector = 0; + file->rwPosition.byte = 0; + } + + if (file->append) { + position = file->appendPosition; + flagAppending = true; + } else { + // If the write pointer is past the end of the file, extend the file to that size + if (file->currentPosition > file->filesize) { + if (!_FAT_file_extend_r (r, file)) { + _FAT_unlock(&partition->lock); + return -1; + } + } + + // Write at current read pointer + position = file->rwPosition; + + // If it is writing past the current end of file, set appending flag + if (len + file->currentPosition > file->filesize) { + flagAppending = true; + } + } + + // Move onto next cluster if needed + _FAT_check_position_for_next_cluster(r, &position, partition, remain, &flagNoError); + + // Align to sector + tempVar = partition->bytesPerSector - position.byte; + if (tempVar > remain) { + tempVar = remain; + } + + if ((tempVar < partition->bytesPerSector) && flagNoError) { + // Write partial sector to disk + _FAT_cache_writePartialSector (cache, ptr, + _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, position.byte, tempVar); + + remain -= tempVar; + ptr += tempVar; + position.byte += tempVar; + + + // Move onto next sector + if (position.byte >= partition->bytesPerSector) { + position.byte = 0; + position.sector ++; + } + } + + // Align to cluster + // tempVar is number of sectors to write + if (remain > (partition->sectorsPerCluster - position.sector) * partition->bytesPerSector) { + tempVar = partition->sectorsPerCluster - position.sector; + } else { + tempVar = remain / partition->bytesPerSector; + } + + if ((tempVar > 0 && tempVar < partition->sectorsPerCluster) && flagNoError) { + if (!_FAT_cache_writeSectors (cache, + _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, tempVar, ptr)) + { + flagNoError = false; + r->_errno = EIO; + } else { + ptr += tempVar * partition->bytesPerSector; + remain -= tempVar * partition->bytesPerSector; + position.sector += tempVar; + } + } + + // Write whole clusters + while ((remain >= partition->bytesPerCluster) && flagNoError) { + // allocate next cluster + _FAT_check_position_for_next_cluster(r, &position, partition, remain, &flagNoError); + if (!flagNoError) break; + // set indexes to the current position + uint32_t chunkEnd = position.cluster; + uint32_t nextChunkStart = position.cluster; + size_t chunkSize = partition->bytesPerCluster; + FILE_POSITION next_position = position; + + // group consecutive clusters + while (flagNoError && +#ifdef LIMIT_SECTORS + (chunkSize + partition->bytesPerCluster <= LIMIT_SECTORS * partition->bytesPerSector) && +#endif + (chunkSize + partition->bytesPerCluster < remain)) + { + // pretend to use up all sectors in next_position + next_position.sector = partition->sectorsPerCluster; + // get or allocate next cluster + _FAT_check_position_for_next_cluster(r, &next_position, partition, + remain - chunkSize, &flagNoError); + if (!flagNoError) break; // exit loop on error + nextChunkStart = next_position.cluster; + if (nextChunkStart != chunkEnd + 1) break; // exit loop if not consecutive + chunkEnd = nextChunkStart; + chunkSize += partition->bytesPerCluster; + } + + if ( !_FAT_cache_writeSectors (cache, + _FAT_fat_clusterToSector(partition, position.cluster), chunkSize / partition->bytesPerSector, ptr)) + { + flagNoError = false; + r->_errno = EIO; + break; + } + ptr += chunkSize; + remain -= chunkSize; + + if ((chunkEnd != nextChunkStart) && _FAT_fat_isValidCluster(partition, nextChunkStart)) { + // new cluster is already allocated (because it was not consecutive) + position.cluster = nextChunkStart; + position.sector = 0; + } else { + // Allocate a new cluster when next writing the file + position.cluster = chunkEnd; + position.sector = partition->sectorsPerCluster; + } + } + + // allocate next cluster if needed + _FAT_check_position_for_next_cluster(r, &position, partition, remain, &flagNoError); + + // Write remaining sectors + tempVar = remain / partition->bytesPerSector; // Number of sectors left + if ((tempVar > 0) && flagNoError) { + if (!_FAT_cache_writeSectors (cache, _FAT_fat_clusterToSector (partition, position.cluster), tempVar, ptr)) + { + flagNoError = false; + r->_errno = EIO; + } else { + ptr += tempVar * partition->bytesPerSector; + remain -= tempVar * partition->bytesPerSector; + position.sector += tempVar; + } + } + + // Last remaining sector + if ((remain > 0) && flagNoError) { + if (flagAppending) { + _FAT_cache_eraseWritePartialSector ( cache, ptr, + _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, 0, remain); + } else { + _FAT_cache_writePartialSector ( cache, ptr, + _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, 0, remain); + } + position.byte += remain; + remain = 0; + } + + + // Amount written is the originally requested amount minus stuff remaining + len = len - remain; + + // Update file information + file->modified = true; + if (file->append) { + // Appending doesn't affect the read pointer + file->appendPosition = position; + file->filesize += len; + } else { + // Writing also shifts the read pointer + file->rwPosition = position; + file->currentPosition += len; + if (file->filesize < file->currentPosition) { + file->filesize = file->currentPosition; + } + } + _FAT_unlock(&partition->lock); + + return len; +} + + +off_t _FAT_seek_r (struct _reent *r, int fd, off_t pos, int dir) { + FILE_STRUCT* file = (FILE_STRUCT*) fd; + PARTITION* partition; + uint32_t cluster, nextCluster; + int clusCount; + off_t newPosition; + uint32_t position; + + if ((file == NULL) || (file->inUse == false)) { + // invalid file + r->_errno = EBADF; + return -1; + } + + partition = file->partition; + _FAT_lock(&partition->lock); + + switch (dir) { + case SEEK_SET: + newPosition = pos; + break; + case SEEK_CUR: + newPosition = (off_t)file->currentPosition + pos; + break; + case SEEK_END: + newPosition = (off_t)file->filesize + pos; + break; + default: + _FAT_unlock(&partition->lock); + r->_errno = EINVAL; + return -1; + } + + if ((pos > 0) && (newPosition < 0)) { + _FAT_unlock(&partition->lock); + r->_errno = EOVERFLOW; + return -1; + } + + // newPosition can only be larger than the FILE_MAX_SIZE on platforms where + // off_t is larger than 32 bits. + if (newPosition < 0 || ((sizeof(newPosition) > 4) && newPosition > (off_t)FILE_MAX_SIZE)) { + _FAT_unlock(&partition->lock); + r->_errno = EINVAL; + return -1; + } + + position = (uint32_t)newPosition; + + // Only change the read/write position if it is within the bounds of the current filesize, + // or at the very edge of the file + if (position <= file->filesize && file->startCluster != CLUSTER_FREE) { + // Calculate where the correct cluster is + // how many clusters from start of file + clusCount = position / partition->bytesPerCluster; + cluster = file->startCluster; + if (position >= file->currentPosition) { + // start from current cluster + int currentCount = file->currentPosition / partition->bytesPerCluster; + if (file->rwPosition.sector == partition->sectorsPerCluster) { + currentCount--; + } + clusCount -= currentCount; + cluster = file->rwPosition.cluster; + } + // Calculate the sector and byte of the current position, + // and store them + file->rwPosition.sector = (position % partition->bytesPerCluster) / partition->bytesPerSector; + file->rwPosition.byte = position % partition->bytesPerSector; + + nextCluster = _FAT_fat_nextCluster (partition, cluster); + while ((clusCount > 0) && (nextCluster != CLUSTER_FREE) && (nextCluster != CLUSTER_EOF)) { + clusCount--; + cluster = nextCluster; + nextCluster = _FAT_fat_nextCluster (partition, cluster); + } + + // Check if ran out of clusters and it needs to allocate a new one + if (clusCount > 0) { + if ((clusCount == 1) && (file->filesize == position) && (file->rwPosition.sector == 0)) { + // Set flag to allocate a new cluster + file->rwPosition.sector = partition->sectorsPerCluster; + file->rwPosition.byte = 0; + } else { + _FAT_unlock(&partition->lock); + r->_errno = EINVAL; + return -1; + } + } + + file->rwPosition.cluster = cluster; + } + + // Save position + file->currentPosition = position; + + _FAT_unlock(&partition->lock); + return position; +} + + + +int _FAT_fstat_r (struct _reent *r, int fd, struct stat *st) { + FILE_STRUCT* file = (FILE_STRUCT*) fd; + PARTITION* partition; + DIR_ENTRY fileEntry; + + if ((file == NULL) || (file->inUse == false)) { + // invalid file + r->_errno = EBADF; + return -1; + } + + partition = file->partition; + _FAT_lock(&partition->lock); + + // Get the file's entry data + fileEntry.dataStart = file->dirEntryStart; + fileEntry.dataEnd = file->dirEntryEnd; + + if (!_FAT_directory_entryFromPosition (partition, &fileEntry)) { + _FAT_unlock(&partition->lock); + r->_errno = EIO; + return -1; + } + + // Fill in the stat struct + _FAT_directory_entryStat (partition, &fileEntry, st); + + // Fix stats that have changed since the file was openned + st->st_ino = (ino_t)(file->startCluster); // The file serial number is the start cluster + st->st_size = file->filesize; // File size + + _FAT_unlock(&partition->lock); + return 0; +} + +int _FAT_ftruncate_r (struct _reent *r, int fd, off_t len) { + FILE_STRUCT* file = (FILE_STRUCT*) fd; + PARTITION* partition; + int ret=0; + uint32_t newSize = (uint32_t)len; + + if (len < 0) { + // Trying to truncate to a negative size + r->_errno = EINVAL; + return -1; + } + + if ((sizeof(len) > 4) && len > (off_t)FILE_MAX_SIZE) { + // Trying to extend the file beyond what FAT supports + r->_errno = EFBIG; + return -1; + } + + if (!file || !file->inUse) { + // invalid file + r->_errno = EBADF; + return -1; + } + + if (!file->write) { + // Read-only file + r->_errno = EINVAL; + return -1; + } + + partition = file->partition; + _FAT_lock(&partition->lock); + + if (newSize > file->filesize) { + // Expanding the file + FILE_POSITION savedPosition; + uint32_t savedOffset; + // Get a new cluster for the start of the file if required + if (file->startCluster == CLUSTER_FREE) { + uint32_t tempNextCluster = _FAT_fat_linkFreeCluster (partition, CLUSTER_FREE); + if (!_FAT_fat_isValidCluster(partition, tempNextCluster)) { + // Couldn't get a cluster, so abort immediately + _FAT_unlock(&partition->lock); + r->_errno = ENOSPC; + return -1; + } + file->startCluster = tempNextCluster; + + file->rwPosition.cluster = file->startCluster; + file->rwPosition.sector = 0; + file->rwPosition.byte = 0; + } + // Save the read/write pointer + savedPosition = file->rwPosition; + savedOffset = file->currentPosition; + // Set the position to the new size + file->currentPosition = newSize; + // Extend the file to the new position + if (!_FAT_file_extend_r (r, file)) { + ret = -1; + } + // Set the append position to the new rwPointer + if (file->append) { + file->appendPosition = file->rwPosition; + } + // Restore the old rwPointer; + file->rwPosition = savedPosition; + file->currentPosition = savedOffset; + } else if (newSize < file->filesize){ + // Shrinking the file + if (len == 0) { + // Cutting the file down to nothing, clear all clusters used + _FAT_fat_clearLinks (partition, file->startCluster); + file->startCluster = CLUSTER_FREE; + + file->appendPosition.cluster = CLUSTER_FREE; + file->appendPosition.sector = 0; + file->appendPosition.byte = 0; + } else { + // Trimming the file down to the required size + unsigned int chainLength; + uint32_t lastCluster; + + // Drop the unneeded end of the cluster chain. + // If the end falls on a cluster boundary, drop that cluster too, + // then set a flag to allocate a cluster as needed + chainLength = ((newSize-1) / partition->bytesPerCluster) + 1; + lastCluster = _FAT_fat_trimChain (partition, file->startCluster, chainLength); + + if (file->append) { + file->appendPosition.byte = newSize % partition->bytesPerSector; + // Does the end of the file fall on the edge of a cluster? + if (newSize % partition->bytesPerCluster == 0) { + // Set a flag to allocate a new cluster + file->appendPosition.sector = partition->sectorsPerCluster; + } else { + file->appendPosition.sector = (newSize % partition->bytesPerCluster) / partition->bytesPerSector; + } + file->appendPosition.cluster = lastCluster; + } + } + } else { + // Truncating to same length, so don't do anything + } + + file->filesize = newSize; + file->modified = true; + + _FAT_unlock(&partition->lock); + return ret; +} + +int _FAT_fsync_r (struct _reent *r, int fd) { + FILE_STRUCT* file = (FILE_STRUCT*) fd; + int ret = 0; + + if (!file->inUse) { + r->_errno = EBADF; + return -1; + } + + _FAT_lock(&file->partition->lock); + + ret = _FAT_syncToDisc (file); + if (ret != 0) { + r->_errno = ret; + ret = -1; + } + + _FAT_unlock(&file->partition->lock); + + return ret; +}