minix/commands/i386/mtools-3.9.7/file.c
2005-04-21 14:53:53 +00:00

676 lines
14 KiB
C
Executable file

#include "sysincludes.h"
#include "msdos.h"
#include "stream.h"
#include "mtools.h"
#include "fsP.h"
#include "file.h"
#include "htable.h"
#include "dirCache.h"
typedef struct File_t {
Class_t *Class;
int refs;
struct Fs_t *Fs; /* Filesystem that this fat file belongs to */
Stream_t *Buffer;
int (*map)(struct File_t *this, off_t where, size_t *len, int mode,
mt_off_t *res);
size_t FileSize;
size_t preallocatedSize;
int preallocatedClusters;
/* Absolute position of first cluster of file */
unsigned int FirstAbsCluNr;
/* Absolute position of previous cluster */
unsigned int PreviousAbsCluNr;
/* Relative position of previous cluster */
unsigned int PreviousRelCluNr;
direntry_t direntry;
int hint;
struct dirCache_t *dcp;
unsigned int loopDetectRel;
unsigned int loopDetectAbs;
} File_t;
static Class_t FileClass;
T_HashTable *filehash;
static File_t *getUnbufferedFile(Stream_t *Stream)
{
while(Stream->Class != &FileClass)
Stream = Stream->Next;
return (File_t *) Stream;
}
Fs_t *getFs(Stream_t *Stream)
{
return getUnbufferedFile(Stream)->Fs;
}
struct dirCache_t **getDirCacheP(Stream_t *Stream)
{
return &getUnbufferedFile(Stream)->dcp;
}
direntry_t *getDirentry(Stream_t *Stream)
{
return &getUnbufferedFile(Stream)->direntry;
}
static int recalcPreallocSize(File_t *This)
{
size_t currentClusters, neededClusters;
int clus_size;
int neededPrealloc;
Fs_t *Fs = This->Fs;
int r;
if(This->FileSize & 0xc0000000) {
fprintf(stderr, "Bad filesize\n");
}
if(This->preallocatedSize & 0xc0000000) {
fprintf(stderr, "Bad preallocated size %x\n",
(int) This->preallocatedSize);
}
clus_size = Fs->cluster_size * Fs->sector_size;
currentClusters = (This->FileSize + clus_size - 1) / clus_size;
neededClusters = (This->preallocatedSize + clus_size - 1) / clus_size;
neededPrealloc = neededClusters - currentClusters;
if(neededPrealloc < 0)
neededPrealloc = 0;
r = fsPreallocateClusters(Fs, neededPrealloc - This->preallocatedClusters);
if(r)
return r;
This->preallocatedClusters = neededPrealloc;
return 0;
}
static int _loopDetect(unsigned int *oldrel, unsigned int rel,
unsigned int *oldabs, unsigned int abs)
{
if(*oldrel && rel > *oldrel && abs == *oldabs) {
fprintf(stderr, "loop detected! oldrel=%d newrel=%d abs=%d\n",
*oldrel, rel, abs);
return -1;
}
if(rel >= 2 * *oldrel + 1) {
*oldrel = rel;
*oldabs = abs;
}
return 0;
}
static int loopDetect(File_t *This, unsigned int rel, unsigned int abs)
{
return _loopDetect(&This->loopDetectRel, rel, &This->loopDetectAbs, abs);
}
static unsigned int _countBlocks(Fs_t *This, unsigned int block)
{
unsigned int blocks;
unsigned int rel, oldabs, oldrel;
blocks = 0;
oldabs = oldrel = rel = 0;
while (block <= This->last_fat && block != 1 && block) {
blocks++;
block = fatDecode(This, block);
rel++;
if(_loopDetect(&oldrel, rel, &oldabs, block) < 0)
block = -1;
}
return blocks;
}
unsigned int countBlocks(Stream_t *Dir, unsigned int block)
{
Stream_t *Stream = GetFs(Dir);
DeclareThis(Fs_t);
return _countBlocks(This, block);
}
/* returns number of bytes in a directory. Represents a file size, and
* can hence be not bigger than 2^32
*/
static size_t countBytes(Stream_t *Dir, unsigned int block)
{
Stream_t *Stream = GetFs(Dir);
DeclareThis(Fs_t);
return _countBlocks(This, block) *
This->sector_size * This->cluster_size;
}
void printFat(Stream_t *Stream)
{
File_t *This = getUnbufferedFile(Stream);
unsigned long n;
int rel;
unsigned long begin, end;
int first;
n = This->FirstAbsCluNr;
if(!n) {
printf("Root directory or empty file\n");
return;
}
rel = 0;
first = 1;
begin = end = 0;
do {
if (first || n != end+1) {
if (!first) {
if (begin != end)
printf("-%lu", end);
printf("> ");
}
begin = end = n;
printf("<%lu", begin);
} else {
end++;
}
first = 0;
n = fatDecode(This->Fs, n);
rel++;
if(loopDetect(This, rel, n) < 0)
n = 1;
} while (n <= This->Fs->last_fat && n != 1);
if(!first) {
if (begin != end)
printf("-%lu", end);
printf(">");
}
}
static int normal_map(File_t *This, off_t where, size_t *len, int mode,
mt_off_t *res)
{
int offset;
off_t end;
int NrClu; /* number of clusters to read */
unsigned int RelCluNr;
unsigned int CurCluNr;
unsigned int NewCluNr;
unsigned int AbsCluNr;
int clus_size;
Fs_t *Fs = This->Fs;
*res = 0;
clus_size = Fs->cluster_size * Fs->sector_size;
offset = where % clus_size;
if (mode == MT_READ)
maximize(*len, This->FileSize - where);
if (*len == 0 )
return 0;
if (This->FirstAbsCluNr < 2){
if( mode == MT_READ || *len == 0){
*len = 0;
return 0;
}
NewCluNr = get_next_free_cluster(This->Fs, 1);
if (NewCluNr == 1 ){
errno = ENOSPC;
return -2;
}
hash_remove(filehash, (void *) This, This->hint);
This->FirstAbsCluNr = NewCluNr;
hash_add(filehash, (void *) This, &This->hint);
fatAllocate(This->Fs, NewCluNr, Fs->end_fat);
}
RelCluNr = where / clus_size;
if (RelCluNr >= This->PreviousRelCluNr){
CurCluNr = This->PreviousRelCluNr;
AbsCluNr = This->PreviousAbsCluNr;
} else {
CurCluNr = 0;
AbsCluNr = This->FirstAbsCluNr;
}
NrClu = (offset + *len - 1) / clus_size;
while (CurCluNr <= RelCluNr + NrClu){
if (CurCluNr == RelCluNr){
/* we have reached the beginning of our zone. Save
* coordinates */
This->PreviousRelCluNr = RelCluNr;
This->PreviousAbsCluNr = AbsCluNr;
}
NewCluNr = fatDecode(This->Fs, AbsCluNr);
if (NewCluNr == 1 || NewCluNr == 0){
fprintf(stderr,"Fat problem while decoding %d %x\n",
AbsCluNr, NewCluNr);
exit(1);
}
if(CurCluNr == RelCluNr + NrClu)
break;
if (NewCluNr > Fs->last_fat && mode == MT_WRITE){
/* if at end, and writing, extend it */
NewCluNr = get_next_free_cluster(This->Fs, AbsCluNr);
if (NewCluNr == 1 ){ /* no more space */
errno = ENOSPC;
return -2;
}
fatAppend(This->Fs, AbsCluNr, NewCluNr);
}
if (CurCluNr < RelCluNr && NewCluNr > Fs->last_fat){
*len = 0;
return 0;
}
if (CurCluNr >= RelCluNr && NewCluNr != AbsCluNr + 1)
break;
CurCluNr++;
AbsCluNr = NewCluNr;
if(loopDetect(This, CurCluNr, AbsCluNr)) {
errno = EIO;
return -2;
}
}
maximize(*len, (1 + CurCluNr - RelCluNr) * clus_size - offset);
end = where + *len;
if(batchmode && mode == MT_WRITE && end >= This->FileSize) {
*len += ROUND_UP(end, clus_size) - end;
}
if((*len + offset) / clus_size + This->PreviousAbsCluNr-2 >
Fs->num_clus) {
fprintf(stderr, "cluster too big\n");
exit(1);
}
*res = sectorsToBytes((Stream_t*)Fs,
(This->PreviousAbsCluNr-2) * Fs->cluster_size +
Fs->clus_start) + offset;
return 1;
}
static int root_map(File_t *This, off_t where, size_t *len, int mode,
mt_off_t *res)
{
Fs_t *Fs = This->Fs;
if(Fs->dir_len * Fs->sector_size < where) {
*len = 0;
errno = ENOSPC;
return -2;
}
maximize(*len, Fs->dir_len * Fs->sector_size - where);
if (*len == 0)
return 0;
*res = sectorsToBytes((Stream_t*)Fs, Fs->dir_start) + where;
return 1;
}
static int read_file(Stream_t *Stream, char *buf, mt_off_t iwhere,
size_t len)
{
DeclareThis(File_t);
mt_off_t pos;
int err;
off_t where = truncBytes32(iwhere);
Stream_t *Disk = This->Fs->Next;
err = This->map(This, where, &len, MT_READ, &pos);
if(err <= 0)
return err;
return READS(Disk, buf, pos, len);
}
static int write_file(Stream_t *Stream, char *buf, mt_off_t iwhere, size_t len)
{
DeclareThis(File_t);
mt_off_t pos;
int ret;
size_t requestedLen;
Stream_t *Disk = This->Fs->Next;
off_t where = truncBytes32(iwhere);
int err;
requestedLen = len;
err = This->map(This, where, &len, MT_WRITE, &pos);
if( err <= 0)
return err;
if(batchmode)
ret = force_write(Disk, buf, pos, len);
else
ret = WRITES(Disk, buf, pos, len);
if(ret > requestedLen)
ret = requestedLen;
if (ret > 0 && where + ret > This->FileSize )
This->FileSize = where + ret;
recalcPreallocSize(This);
return ret;
}
/*
* Convert an MSDOS time & date stamp to the Unix time() format
*/
static int month[] = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334,
0, 0, 0 };
static inline time_t conv_stamp(struct directory *dir)
{
struct tm *tmbuf;
long tzone, dst;
time_t accum, tmp;
accum = DOS_YEAR(dir) - 1970; /* years past */
/* days passed */
accum = accum * 365L + month[DOS_MONTH(dir)-1] + DOS_DAY(dir);
/* leap years */
accum += (DOS_YEAR(dir) - 1972) / 4L;
/* back off 1 day if before 29 Feb */
if (!(DOS_YEAR(dir) % 4) && DOS_MONTH(dir) < 3)
accum--;
accum = accum * 24L + DOS_HOUR(dir); /* hours passed */
accum = accum * 60L + DOS_MINUTE(dir); /* minutes passed */
accum = accum * 60L + DOS_SEC(dir); /* seconds passed */
#ifndef OS_Minix
/* correct for Time Zone */
#ifdef HAVE_GETTIMEOFDAY
{
struct timeval tv;
struct timezone tz;
gettimeofday(&tv, &tz);
tzone = tz.tz_minuteswest * 60L;
}
#else
#ifdef HAVE_TZSET
{
#ifndef OS_ultrix
/* Ultrix defines this to be a different type */
extern long timezone;
#endif
tzset();
tzone = (long) timezone;
}
#else
tzone = 0;
#endif /* HAVE_TZSET */
#endif /* HAVE_GETTIMEOFDAY */
accum += tzone;
#endif /* OS_Minix */
/* correct for Daylight Saving Time */
tmp = accum;
tmbuf = localtime(&tmp);
#ifndef OS_Minix
dst = (tmbuf->tm_isdst) ? (-60L * 60L) : 0L;
accum += dst;
#endif
return accum;
}
static int get_file_data(Stream_t *Stream, time_t *date, mt_size_t *size,
int *type, int *address)
{
DeclareThis(File_t);
if(date)
*date = conv_stamp(& This->direntry.dir);
if(size)
*size = (mt_size_t) This->FileSize;
if(type)
*type = This->direntry.dir.attr & ATTR_DIR;
if(address)
*address = This->FirstAbsCluNr;
return 0;
}
static int free_file(Stream_t *Stream)
{
DeclareThis(File_t);
Fs_t *Fs = This->Fs;
fsPreallocateClusters(Fs, -This->preallocatedClusters);
FREE(&This->direntry.Dir);
freeDirCache(Stream);
return hash_remove(filehash, (void *) Stream, This->hint);
}
static int flush_file(Stream_t *Stream)
{
DeclareThis(File_t);
direntry_t *entry = &This->direntry;
if(isRootDir(Stream)) {
return 0;
}
if(This->FirstAbsCluNr != getStart(entry->Dir, &entry->dir)) {
set_word(entry->dir.start, This->FirstAbsCluNr & 0xffff);
set_word(entry->dir.startHi, This->FirstAbsCluNr >> 16);
dir_write(entry);
}
return 0;
}
static int pre_allocate_file(Stream_t *Stream, mt_size_t isize)
{
DeclareThis(File_t);
size_t size = truncBytes32(isize);
if(size > This->FileSize &&
size > This->preallocatedSize) {
This->preallocatedSize = size;
return recalcPreallocSize(This);
} else
return 0;
}
static Class_t FileClass = {
read_file,
write_file,
flush_file, /* flush */
free_file, /* free */
0, /* get_geom */
get_file_data,
pre_allocate_file
};
static unsigned int getAbsCluNr(File_t *This)
{
if(This->FirstAbsCluNr)
return This->FirstAbsCluNr;
if(isRootDir((Stream_t *) This))
return 0;
return 1;
}
static unsigned int func1(void *Stream)
{
DeclareThis(File_t);
return getAbsCluNr(This) ^ (long) This->Fs;
}
static unsigned int func2(void *Stream)
{
DeclareThis(File_t);
return getAbsCluNr(This);
}
static int comp(void *Stream, void *Stream2)
{
DeclareThis(File_t);
File_t *This2 = (File_t *) Stream2;
return This->Fs != This2->Fs ||
getAbsCluNr(This) != getAbsCluNr(This2);
}
static void init_hash(void)
{
static int is_initialised=0;
if(!is_initialised){
make_ht(func1, func2, comp, 20, &filehash);
is_initialised = 1;
}
}
static Stream_t *_internalFileOpen(Stream_t *Dir, unsigned int first,
size_t size, direntry_t *entry)
{
Stream_t *Stream = GetFs(Dir);
DeclareThis(Fs_t);
File_t Pattern;
File_t *File;
init_hash();
This->refs++;
if(first != 1){
/* we use the illegal cluster 1 to mark newly created files.
* do not manage those by hashtable */
Pattern.Fs = This;
Pattern.Class = &FileClass;
if(first || (entry && !IS_DIR(entry)))
Pattern.map = normal_map;
else
Pattern.map = root_map;
Pattern.FirstAbsCluNr = first;
Pattern.loopDetectRel = 0;
Pattern.loopDetectAbs = first;
if(!hash_lookup(filehash, (T_HashTableEl) &Pattern,
(T_HashTableEl **)&File, 0)){
File->refs++;
This->refs--;
return (Stream_t *) File;
}
}
File = New(File_t);
if (!File)
return NULL;
File->dcp = 0;
File->preallocatedClusters = 0;
File->preallocatedSize = 0;
/* memorize dir for date and attrib */
File->direntry = *entry;
if(entry->entry == -3)
File->direntry.Dir = (Stream_t *) File; /* root directory */
else
COPY(File->direntry.Dir);
File->Class = &FileClass;
File->Fs = This;
if(first || (entry && !IS_DIR(entry)))
File->map = normal_map;
else
File->map = root_map; /* FAT 12/16 root directory */
if(first == 1)
File->FirstAbsCluNr = 0;
else
File->FirstAbsCluNr = first;
File->loopDetectRel = 0;
File->loopDetectAbs = 0;
File->PreviousRelCluNr = 0xffff;
File->FileSize = size;
File->refs = 1;
File->Buffer = 0;
hash_add(filehash, (void *) File, &File->hint);
return (Stream_t *) File;
}
Stream_t *OpenRoot(Stream_t *Dir)
{
unsigned int num;
direntry_t entry;
size_t size;
Stream_t *file;
memset(&entry, 0, sizeof(direntry_t));
num = fat32RootCluster(Dir);
/* make the directory entry */
entry.entry = -3;
entry.name[0] = '\0';
mk_entry("/", ATTR_DIR, num, 0, 0, &entry.dir);
if(num)
size = countBytes(Dir, num);
else {
Fs_t *Fs = (Fs_t *) GetFs(Dir);
size = Fs->dir_len * Fs->sector_size;
}
file = _internalFileOpen(Dir, num, size, &entry);
bufferize(&file);
return file;
}
Stream_t *OpenFileByDirentry(direntry_t *entry)
{
Stream_t *file;
unsigned int first;
size_t size;
first = getStart(entry->Dir, &entry->dir);
if(!first && IS_DIR(entry))
return OpenRoot(entry->Dir);
if (IS_DIR(entry))
size = countBytes(entry->Dir, first);
else
size = FILE_SIZE(&entry->dir);
file = _internalFileOpen(entry->Dir, first, size, entry);
if(IS_DIR(entry)) {
bufferize(&file);
if(first == 1)
dir_grow(file, 0);
}
return file;
}
int isRootDir(Stream_t *Stream)
{
File_t *This = getUnbufferedFile(Stream);
return This->map == root_map;
}