1 files changed, 230 insertions, 0 deletions

diff --git a/dosfstools/src/io.c b/dosfstools/src/io.c
new file mode 100644
index 000000000..a703c2db1
--- /dev/null
+++ b/dosfstools/src/io.c
@@ -0,0 +1,230 @@
+/* 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> */
+
+#define _LARGEFILE64_SOURCE
+#include <sys/types.h>
+#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 */
+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)
+#else
+loff_t llseek(int fd, loff_t offset, int whence)
+{
+    return (loff_t) lseek64(fd, (off64_t) offset, whence);
+}
+#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
+}
+
+/**
+ * Read data from the partition, accounting for any pending updates that are
+ * queued for writing.
+ *
+ * @param[in]   pos     Byte offset, relative to the beginning of the partition,
+ *                      at which to read
+ * @param[in]   size    Number of bytes to read
+ * @param[out]  data    Where to put the data read
+ */
+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;
+}