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a711f2bef2
A relatively rare concurrency bug existed in these methods due to them not correctly holding the partition lock during calls to _FAT_directory_entryFromPath. That method can trigger reads to the partition. Due to the lock not being held, another thread could still trigger a concurrent read, potentially corrupting the cache. The fix is simply to ensure the lock is held around the calls.
1219 lines
35 KiB
C
1219 lines
35 KiB
C
/*
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fatfile.c
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Functions used by the newlib disc stubs to interface with
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this library
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Copyright (c) 2006 Michael "Chishm" Chisholm
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Redistribution and use in source and binary forms, with or without modification,
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are permitted provided that the following conditions are met:
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1. Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions and the following disclaimer in the documentation and/or
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other materials provided with the distribution.
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3. The name of the author may not be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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2009-10-23 oggzee: fixes for cluster aligned file size (write, truncate, seek)
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*/
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#include "fatfile.h"
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#include <fcntl.h>
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#include <string.h>
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#include <errno.h>
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#include <ctype.h>
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#include <unistd.h>
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#include "cache.h"
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#include "file_allocation_table.h"
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#include "bit_ops.h"
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#include "filetime.h"
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#include "lock.h"
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bool _FAT_findEntry(const char *path, DIR_ENTRY *dirEntry) {
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bool r;
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PARTITION *partition = _FAT_partition_getPartitionFromPath(path);
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// Check Partition
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if( !partition )
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return false;
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// Move the path pointer to the start of the actual path
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if (strchr (path, ':') != NULL) {
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path = strchr (path, ':') + 1;
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}
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if (strchr (path, ':') != NULL) {
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return false;
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}
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// Search for the file on the disc
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_FAT_lock(&partition->lock);
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r = _FAT_directory_entryFromPath (partition, dirEntry, path, NULL);
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_FAT_unlock(&partition->lock);
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return r;
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}
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int FAT_getAttr(const char *file) {
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DIR_ENTRY dirEntry;
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if (!_FAT_findEntry(file,&dirEntry)) return -1;
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return dirEntry.entryData[DIR_ENTRY_attributes];
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}
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int FAT_setAttr(const char *file, uint8_t attr) {
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// Defines...
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DIR_ENTRY_POSITION entryEnd;
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PARTITION *partition = NULL;
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DIR_ENTRY dirEntry;
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// Get Partition
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partition = _FAT_partition_getPartitionFromPath( file );
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// Check Partition
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if( !partition )
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return -1;
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// Move the path pointer to the start of the actual path
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if (strchr (file, ':') != NULL)
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file = strchr (file, ':') + 1;
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if (strchr (file, ':') != NULL)
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return -1;
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// Lock Partition
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_FAT_lock(&partition->lock);
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// Get DIR_ENTRY
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if( !_FAT_directory_entryFromPath (partition, &dirEntry, file, NULL) ) {
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_FAT_unlock(&partition->lock); // Unlock Partition
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return -1;
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}
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// Get Entry-End
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entryEnd = dirEntry.dataEnd;
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// Write Data
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_FAT_cache_writePartialSector (
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partition->cache // Cache to write
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, &attr // Value to be written
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, _FAT_fat_clusterToSector( partition , entryEnd.cluster ) + entryEnd.sector // cluster
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, entryEnd.offset * DIR_ENTRY_DATA_SIZE + DIR_ENTRY_attributes // offset
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, 1 // Size in bytes
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);
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// Flush any sectors in the disc cache
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if ( !_FAT_cache_flush( partition->cache ) ) {
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_FAT_unlock(&partition->lock); // Unlock Partition
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return -1;
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}
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// Unlock Partition
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_FAT_unlock(&partition->lock);
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return 0;
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}
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int _FAT_open_r (struct _reent *r, void *fileStruct, const char *path, int flags, int mode) {
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PARTITION* partition = NULL;
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bool fileExists;
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DIR_ENTRY dirEntry;
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const char* pathEnd;
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uint32_t dirCluster;
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FILE_STRUCT* file = (FILE_STRUCT*) fileStruct;
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partition = _FAT_partition_getPartitionFromPath (path);
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if (partition == NULL) {
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r->_errno = ENODEV;
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return -1;
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}
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// Move the path pointer to the start of the actual path
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if (strchr (path, ':') != NULL) {
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path = strchr (path, ':') + 1;
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}
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if (strchr (path, ':') != NULL) {
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r->_errno = EINVAL;
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return -1;
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}
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// Determine which mode the file is openned for
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if ((flags & 0x03) == O_RDONLY) {
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// Open the file for read-only access
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file->read = true;
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file->write = false;
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file->append = false;
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} else if ((flags & 0x03) == O_WRONLY) {
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// Open file for write only access
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file->read = false;
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file->write = true;
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file->append = false;
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} else if ((flags & 0x03) == O_RDWR) {
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// Open file for read/write access
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file->read = true;
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file->write = true;
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file->append = false;
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} else {
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r->_errno = EACCES;
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return -1;
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}
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// Make sure we aren't trying to write to a read-only disc
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if (file->write && partition->readOnly) {
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r->_errno = EROFS;
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return -1;
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}
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// Search for the file on the disc
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_FAT_lock(&partition->lock);
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fileExists = _FAT_directory_entryFromPath (partition, &dirEntry, path, NULL);
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// The file shouldn't exist if we are trying to create it
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if ((flags & O_CREAT) && (flags & O_EXCL) && fileExists) {
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_FAT_unlock(&partition->lock);
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r->_errno = EEXIST;
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return -1;
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}
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// It should not be a directory if we're openning a file,
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if (fileExists && _FAT_directory_isDirectory(&dirEntry)) {
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_FAT_unlock(&partition->lock);
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r->_errno = EISDIR;
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return -1;
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}
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// We haven't modified the file yet
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file->modified = false;
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// If the file doesn't exist, create it if we're allowed to
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if (!fileExists) {
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if (flags & O_CREAT) {
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if (partition->readOnly) {
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// We can't write to a read-only partition
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_FAT_unlock(&partition->lock);
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r->_errno = EROFS;
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return -1;
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}
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// Create the file
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// Get the directory it has to go in
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pathEnd = strrchr (path, DIR_SEPARATOR);
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if (pathEnd == NULL) {
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// No path was specified
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dirCluster = partition->cwdCluster;
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pathEnd = path;
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} else {
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// Path was specified -- get the right dirCluster
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// Recycling dirEntry, since it needs to be recreated anyway
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if (!_FAT_directory_entryFromPath (partition, &dirEntry, path, pathEnd) ||
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!_FAT_directory_isDirectory(&dirEntry)) {
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_FAT_unlock(&partition->lock);
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r->_errno = ENOTDIR;
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return -1;
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}
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dirCluster = _FAT_directory_entryGetCluster (partition, dirEntry.entryData);
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// Move the pathEnd past the last DIR_SEPARATOR
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pathEnd += 1;
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}
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// Create the entry data
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strncpy (dirEntry.filename, pathEnd, NAME_MAX - 1);
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memset (dirEntry.entryData, 0, DIR_ENTRY_DATA_SIZE);
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// Set the creation time and date
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dirEntry.entryData[DIR_ENTRY_cTime_ms] = 0;
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u16_to_u8array (dirEntry.entryData, DIR_ENTRY_cTime, _FAT_filetime_getTimeFromRTC());
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u16_to_u8array (dirEntry.entryData, DIR_ENTRY_cDate, _FAT_filetime_getDateFromRTC());
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if (!_FAT_directory_addEntry (partition, &dirEntry, dirCluster)) {
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_FAT_unlock(&partition->lock);
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r->_errno = ENOSPC;
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return -1;
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}
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// File entry is modified
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file->modified = true;
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} else {
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// file doesn't exist, and we aren't creating it
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_FAT_unlock(&partition->lock);
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r->_errno = ENOENT;
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return -1;
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}
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}
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file->filesize = u8array_to_u32 (dirEntry.entryData, DIR_ENTRY_fileSize);
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/* Allow LARGEFILEs with undefined results
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// Make sure that the file size can fit in the available space
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if (!(flags & O_LARGEFILE) && (file->filesize >= (1<<31))) {
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r->_errno = EFBIG;
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return -1;
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}
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*/
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// Make sure we aren't trying to write to a read-only file
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if (file->write && !_FAT_directory_isWritable(&dirEntry)) {
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_FAT_unlock(&partition->lock);
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r->_errno = EROFS;
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return -1;
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}
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// Associate this file with a particular partition
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file->partition = partition;
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file->startCluster = _FAT_directory_entryGetCluster (partition, dirEntry.entryData);
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// Truncate the file if requested
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if ((flags & O_TRUNC) && file->write && (file->startCluster != 0)) {
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_FAT_fat_clearLinks (partition, file->startCluster);
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file->startCluster = CLUSTER_FREE;
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file->filesize = 0;
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// File is modified since we just cut it all off
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file->modified = true;
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}
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// Remember the position of this file's directory entry
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file->dirEntryStart = dirEntry.dataStart; // Points to the start of the LFN entries of a file, or the alias for no LFN
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file->dirEntryEnd = dirEntry.dataEnd;
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// Reset read/write pointer
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file->currentPosition = 0;
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file->rwPosition.cluster = file->startCluster;
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file->rwPosition.sector = 0;
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file->rwPosition.byte = 0;
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if (flags & O_APPEND) {
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file->append = true;
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// Set append pointer to the end of the file
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file->appendPosition.cluster = _FAT_fat_lastCluster (partition, file->startCluster);
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file->appendPosition.sector = (file->filesize % partition->bytesPerCluster) / partition->bytesPerSector;
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file->appendPosition.byte = file->filesize % partition->bytesPerSector;
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// Check if the end of the file is on the end of a cluster
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if ( (file->filesize > 0) && ((file->filesize % partition->bytesPerCluster)==0) ){
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// Set flag to allocate a new cluster
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file->appendPosition.sector = partition->sectorsPerCluster;
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file->appendPosition.byte = 0;
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}
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} else {
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file->append = false;
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// Use something sane for the append pointer, so the whole file struct contains known values
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file->appendPosition = file->rwPosition;
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}
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file->inUse = true;
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// Insert this file into the double-linked list of open files
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partition->openFileCount += 1;
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if (partition->firstOpenFile) {
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file->nextOpenFile = partition->firstOpenFile;
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partition->firstOpenFile->prevOpenFile = file;
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} else {
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file->nextOpenFile = NULL;
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}
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file->prevOpenFile = NULL;
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partition->firstOpenFile = file;
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_FAT_unlock(&partition->lock);
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return (int) file;
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}
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/*
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Synchronizes the file data to disc.
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Does no locking of its own -- lock the partition before calling.
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Returns 0 on success, an error code on failure.
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*/
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int _FAT_syncToDisc (FILE_STRUCT* file) {
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uint8_t dirEntryData[DIR_ENTRY_DATA_SIZE];
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if (!file || !file->inUse) {
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return EBADF;
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}
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if (file->write && file->modified) {
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// Load the old entry
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_FAT_cache_readPartialSector (file->partition->cache, dirEntryData,
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_FAT_fat_clusterToSector(file->partition, file->dirEntryEnd.cluster) + file->dirEntryEnd.sector,
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file->dirEntryEnd.offset * DIR_ENTRY_DATA_SIZE, DIR_ENTRY_DATA_SIZE);
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// Write new data to the directory entry
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// File size
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u32_to_u8array (dirEntryData, DIR_ENTRY_fileSize, file->filesize);
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// Start cluster
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u16_to_u8array (dirEntryData, DIR_ENTRY_cluster, file->startCluster);
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u16_to_u8array (dirEntryData, DIR_ENTRY_clusterHigh, file->startCluster >> 16);
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// Modification time and date
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u16_to_u8array (dirEntryData, DIR_ENTRY_mTime, _FAT_filetime_getTimeFromRTC());
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u16_to_u8array (dirEntryData, DIR_ENTRY_mDate, _FAT_filetime_getDateFromRTC());
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// Access date
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u16_to_u8array (dirEntryData, DIR_ENTRY_aDate, _FAT_filetime_getDateFromRTC());
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// Set archive attribute
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dirEntryData[DIR_ENTRY_attributes] |= ATTRIB_ARCH;
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// Write the new entry
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_FAT_cache_writePartialSector (file->partition->cache, dirEntryData,
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_FAT_fat_clusterToSector(file->partition, file->dirEntryEnd.cluster) + file->dirEntryEnd.sector,
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file->dirEntryEnd.offset * DIR_ENTRY_DATA_SIZE, DIR_ENTRY_DATA_SIZE);
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// Flush any sectors in the disc cache
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if (!_FAT_cache_flush(file->partition->cache)) {
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return EIO;
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}
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}
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file->modified = false;
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return 0;
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}
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int _FAT_close_r (struct _reent *r, void *fd) {
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FILE_STRUCT* file = (FILE_STRUCT*) fd;
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int ret = 0;
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if (!file->inUse) {
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r->_errno = EBADF;
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return -1;
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}
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_FAT_lock(&file->partition->lock);
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if (file->write) {
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ret = _FAT_syncToDisc (file);
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if (ret != 0) {
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r->_errno = ret;
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ret = -1;
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}
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}
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file->inUse = false;
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// Remove this file from the double-linked list of open files
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file->partition->openFileCount -= 1;
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if (file->nextOpenFile) {
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file->nextOpenFile->prevOpenFile = file->prevOpenFile;
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}
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if (file->prevOpenFile) {
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file->prevOpenFile->nextOpenFile = file->nextOpenFile;
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} else {
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file->partition->firstOpenFile = file->nextOpenFile;
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}
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_FAT_unlock(&file->partition->lock);
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return ret;
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}
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ssize_t _FAT_read_r (struct _reent *r, void *fd, char *ptr, size_t len) {
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FILE_STRUCT* file = (FILE_STRUCT*) fd;
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PARTITION* partition;
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CACHE* cache;
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FILE_POSITION position;
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uint32_t tempNextCluster;
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unsigned int tempVar;
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size_t remain;
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bool flagNoError = true;
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// Short circuit cases where len is 0 (or less)
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if (len <= 0) {
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return 0;
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}
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// Make sure we can actually read from the file
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if ((file == NULL) || !file->inUse || !file->read) {
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r->_errno = EBADF;
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return -1;
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}
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partition = file->partition;
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_FAT_lock(&partition->lock);
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// Don't try to read if the read pointer is past the end of file
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if (file->currentPosition >= file->filesize || file->startCluster == CLUSTER_FREE) {
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r->_errno = EOVERFLOW;
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_FAT_unlock(&partition->lock);
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return 0;
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}
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// Don't read past end of file
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if (len + file->currentPosition > file->filesize) {
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r->_errno = EOVERFLOW;
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len = file->filesize - file->currentPosition;
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}
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remain = len;
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position = file->rwPosition;
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cache = file->partition->cache;
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// Align to sector
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tempVar = partition->bytesPerSector - position.byte;
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if (tempVar > remain) {
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tempVar = remain;
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}
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if ((tempVar < partition->bytesPerSector) && flagNoError)
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{
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_FAT_cache_readPartialSector ( cache, ptr, _FAT_fat_clusterToSector (partition, position.cluster) + position.sector,
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position.byte, tempVar);
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remain -= tempVar;
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ptr += tempVar;
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position.byte += tempVar;
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if (position.byte >= partition->bytesPerSector) {
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position.byte = 0;
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position.sector++;
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}
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}
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// align to cluster
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// tempVar is number of sectors to read
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if (remain > (partition->sectorsPerCluster - position.sector) * partition->bytesPerSector) {
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tempVar = partition->sectorsPerCluster - position.sector;
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} else {
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tempVar = remain / partition->bytesPerSector;
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}
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if ((tempVar > 0) && flagNoError) {
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if (! _FAT_cache_readSectors (cache, _FAT_fat_clusterToSector (partition, position.cluster) + position.sector,
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tempVar, ptr))
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{
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flagNoError = false;
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r->_errno = EIO;
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} else {
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ptr += tempVar * partition->bytesPerSector;
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remain -= tempVar * partition->bytesPerSector;
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position.sector += tempVar;
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}
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}
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// Move onto next cluster
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// It should get to here without reading anything if a cluster is due to be allocated
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if ((position.sector >= partition->sectorsPerCluster) && flagNoError) {
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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 (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, void *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, void *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, void *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, void *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, void *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;
|
|
}
|