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/* Copyright (C) 2001-2005 by Hans Reiser, licensing governed by
reiser4progs/COPYING.
backup.c -- backup and rollback fsck changes code. */
#ifndef _GNU_SOURCE
# define _GNU_SOURCE
#endif
#include <backup.h>
backup_t backup;
static errno_t backup_write(
aal_device_t *device, /* file device, data will be wrote onto */
void *buff, /* buffer, data stored in */
blk_t block, /* start position for writing */
count_t count)
{
blk_t blk, end;
end = block + count;
for (blk = block; blk < end; blk++) {
/* Check if the block is written already. */
if (reiser4_bitmap_test(backup.bitmap, blk))
continue;
/* Mark it in the bitmap. */
reiser4_bitmap_mark(backup.bitmap, blk);
/* Write block number and data into the backup stream. */
fwrite(&blk, sizeof(blk), 1, backup.file);
fwrite(buff, device->blksize, 1, backup.file);
}
return backup.write(device, buff, block, count);
}
errno_t backup_init(FILE *file, aal_device_t *device, count_t len) {
aal_memset(&backup, 0, sizeof(backup));
if (!file) return 0;
aal_assert("vpf-1511", device != NULL);
backup.file = file;
if (!(backup.bitmap = reiser4_bitmap_create(len))) {
aal_error("Failed to allocate a bitmap for the backup.");
return -ENOMEM;
}
backup.write = device->ops->write;
device->ops->write = backup_write;
/* Write header to the file. */
fwrite(BACKUP_MAGIC, sizeof(BACKUP_MAGIC), 1, backup.file);
fwrite(&device->blksize, sizeof(device->blksize), 1, backup.file);
return 0;
}
void backup_fini() {
if (!backup.file) return;
fclose(backup.file);
reiser4_bitmap_close(backup.bitmap);
}
errno_t backup_rollback(FILE *file, aal_device_t *device) {
char buf[sizeof(BACKUP_MAGIC)];
uint32_t size;
count_t count;
void *data;
blk_t blk;
aal_assert("vpf-1512", file != NULL);
aal_assert("vpf-1513", device != NULL);
if ((count = fread(buf, sizeof(BACKUP_MAGIC), 1, file)) != 1) {
aal_error("Failed to read from the backup file.");
return -EIO;
}
if (aal_strncmp(buf, BACKUP_MAGIC, sizeof(BACKUP_MAGIC))) {
aal_error("Specified file does not look like a backup one.");
return -EIO;
}
if ((count = fread(&size, sizeof(size), 1, file)) != 1) {
aal_error("Failed to read from the backup file.");
return -EIO;
}
if (!(data = aal_malloc(size))) {
aal_error("Failed to alloc the buffer for rollback.");
return -ENOMEM;
}
while (1) {
/* Read from the backup file. */
count = fread(&blk, sizeof(blk), 1, file);
if (count != 1) {
if (feof(file))
break;
goto error_free_data;
}
if ((count = fread(data, size, 1, file)) != 1) {
aal_error("Failed to read from the backup file.");
goto error_free_data;
}
/* Write to the device. */
aal_device_write(device, data, blk, 1);
}
return 0;
error_free_data:
aal_error("Failed to read from the backup file.");
aal_free(data);
return -EIO;
}
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