| /* io.c - Virtual disk input/output |
| |
| Copyright (C) 1993 Werner Almesberger <werner.almesberger@lrc.di.epfl.ch> |
| Copyright (C) 1998 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation, either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. |
| |
| On Debian systems, the complete text of the GNU General Public License |
| can be found in /usr/share/common-licenses/GPL-3 file. |
| */ |
| |
| /* |
| * Thu Feb 26 01:15:36 CET 1998: Martin Schulze <joey@infodrom.north.de> |
| * Fixed nasty bug that caused every file with a name like |
| * xxxxxxxx.xxx to be treated as bad name that needed to be fixed. |
| */ |
| |
| /* FAT32, VFAT, Atari format support, and various fixes additions May 1998 |
| * by Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> */ |
| |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <sys/stat.h> |
| #include <sys/ioctl.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <linux/fd.h> |
| |
| #include "dosfsck.h" |
| #include "common.h" |
| #include "io.h" |
| |
| |
| typedef struct _change { |
| void *data; |
| loff_t pos; |
| int size; |
| struct _change *next; |
| } CHANGE; |
| |
| |
| static CHANGE *changes,*last; |
| static int fd,did_change = 0; |
| |
| unsigned device_no; |
| |
| |
| #ifdef __DJGPP__ |
| #include "volume.h" /* DOS lowlevel disk access functions */ |
| #undef llseek |
| static loff_t llseek( int fd, loff_t offset, int whence ) |
| { |
| if ((whence != SEEK_SET) || (fd == 4711)) return -1; /* only those supported */ |
| return VolumeSeek(offset); |
| } |
| #define open OpenVolume |
| #define close CloseVolume |
| #define read(a,b,c) ReadVolume(b,c) |
| #define write(a,b,c) WriteVolume(b,c) |
| #endif |
| |
| void fs_open(char *path,int rw) |
| { |
| struct stat stbuf; |
| |
| if ((fd = open(path,rw ? O_RDWR : O_RDONLY)) < 0) { |
| perror("open"); |
| exit(6); |
| } |
| changes = last = NULL; |
| did_change = 0; |
| |
| #ifndef _DJGPP_ |
| if (fstat(fd,&stbuf) < 0) |
| pdie("fstat %s",path); |
| device_no = S_ISBLK(stbuf.st_mode) ? (stbuf.st_rdev >> 8) & 0xff : 0; |
| #else |
| if (IsWorkingOnImageFile()) { |
| if (fstat(GetVolumeHandle(),&stbuf) < 0) |
| pdie("fstat image %s",path); |
| device_no = 0; |
| } |
| else { |
| /* return 2 for floppy, 1 for ramdisk, 7 for loopback */ |
| /* used by boot.c in Atari mode: floppy always FAT12, */ |
| /* loopback / ramdisk only FAT12 if usual floppy size, */ |
| /* harddisk always FAT16 on Atari... */ |
| device_no = (GetVolumeHandle() < 2) ? 2 : 1; |
| /* telling "floppy" for A:/B:, "ramdisk" for the rest */ |
| } |
| #endif |
| } |
| |
| |
| void fs_read(loff_t pos,int size,void *data) |
| { |
| CHANGE *walk; |
| int got; |
| |
| if (llseek(fd,pos,0) != pos) pdie("Seek to %lld",pos); |
| if ((got = read(fd,data,size)) < 0) pdie("Read %d bytes at %lld",size,pos); |
| if (got != size) die("Got %d bytes instead of %d at %lld",got,size,pos); |
| for (walk = changes; walk; walk = walk->next) { |
| if (walk->pos < pos+size && walk->pos+walk->size > pos) { |
| if (walk->pos < pos) |
| memcpy(data,(char *) walk->data+pos-walk->pos,min(size, |
| walk->size-pos+walk->pos)); |
| else memcpy((char *) data+walk->pos-pos,walk->data,min(walk->size, |
| size+pos-walk->pos)); |
| } |
| } |
| } |
| |
| |
| int fs_test(loff_t pos,int size) |
| { |
| void *scratch; |
| int okay; |
| |
| if (llseek(fd,pos,0) != pos) pdie("Seek to %lld",pos); |
| scratch = alloc(size); |
| okay = read(fd,scratch,size) == size; |
| free(scratch); |
| return okay; |
| } |
| |
| |
| void fs_write(loff_t pos,int size,void *data) |
| { |
| CHANGE *new; |
| int did; |
| |
| if (write_immed) { |
| did_change = 1; |
| if (llseek(fd,pos,0) != pos) pdie("Seek to %lld",pos); |
| if ((did = write(fd,data,size)) == size) return; |
| if (did < 0) pdie("Write %d bytes at %lld",size,pos); |
| die("Wrote %d bytes instead of %d at %lld",did,size,pos); |
| } |
| new = alloc(sizeof(CHANGE)); |
| new->pos = pos; |
| memcpy(new->data = alloc(new->size = size),data,size); |
| new->next = NULL; |
| if (last) last->next = new; |
| else changes = new; |
| last = new; |
| } |
| |
| |
| static void fs_flush(void) |
| { |
| CHANGE *this; |
| int size; |
| |
| while (changes) { |
| this = changes; |
| changes = changes->next; |
| if (llseek(fd,this->pos,0) != this->pos) |
| fprintf(stderr,"Seek to %lld failed: %s\n Did not write %d bytes.\n", |
| (long long)this->pos,strerror(errno),this->size); |
| else if ((size = write(fd,this->data,this->size)) < 0) |
| fprintf(stderr,"Writing %d bytes at %lld failed: %s\n",this->size, |
| (long long)this->pos,strerror(errno)); |
| else if (size != this->size) |
| fprintf(stderr,"Wrote %d bytes instead of %d bytes at %lld." |
| "\n",size,this->size,(long long)this->pos); |
| free(this->data); |
| free(this); |
| } |
| } |
| |
| |
| int fs_close(int write) |
| { |
| CHANGE *next; |
| int changed; |
| |
| changed = !!changes; |
| if (write) fs_flush(); |
| else while (changes) { |
| next = changes->next; |
| free(changes->data); |
| free(changes); |
| changes = next; |
| } |
| if (close(fd) < 0) pdie("closing file system"); |
| return changed || did_change; |
| } |
| |
| |
| int fs_changed(void) |
| { |
| return !!changes || did_change; |
| } |
| |
| /* Local Variables: */ |
| /* tab-width: 8 */ |
| /* End: */ |