e2fsprogs/e2fsck/ehandler.c
Darrick J. Wong fac0c8ead8 e2fsck: on read error, don't rewrite blocks past the end of the fs
If e2fsck encounters a read error on a block past the end of the
filesystem, don't bother trying to "rewrite" the block.  We might
still want to re-try the read to capture FS data marooned past the end
of the filesystem, but in that case e2fsck ought to move the block
back inside the filesystem.

This enables e2fuzz to detect writes past the end of the FS due to
software bugs.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-01-27 13:12:37 -05:00

134 lines
3.1 KiB
C

/*
* ehandler.c --- handle bad block errors which come up during the
* course of an e2fsck session.
*
* Copyright (C) 1994 Theodore Ts'o. This file may be redistributed
* under the terms of the GNU Public License.
*/
#include "config.h"
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <termios.h>
#include "e2fsck.h"
#include <sys/time.h>
#include <sys/resource.h>
static const char *operation;
static errcode_t e2fsck_handle_read_error(io_channel channel,
unsigned long block,
int count,
void *data,
size_t size EXT2FS_ATTR((unused)),
int actual EXT2FS_ATTR((unused)),
errcode_t error)
{
int i;
char *p;
ext2_filsys fs = (ext2_filsys) channel->app_data;
e2fsck_t ctx;
ctx = (e2fsck_t) fs->priv_data;
if (ctx->flags & E2F_FLAG_EXITING)
return 0;
/*
* If more than one block was read, try reading each block
* separately. We could use the actual bytes read to figure
* out where to start, but we don't bother.
*/
if (count > 1) {
p = (char *) data;
for (i=0; i < count; i++, p += channel->block_size, block++) {
error = io_channel_read_blk64(channel, block,
1, p);
if (error)
return error;
}
return 0;
}
if (operation)
printf(_("Error reading block %lu (%s) while %s. "), block,
error_message(error), operation);
else
printf(_("Error reading block %lu (%s). "), block,
error_message(error));
preenhalt(ctx);
/* Don't rewrite a block past the end of the FS. */
if (block >= ext2fs_blocks_count(fs->super))
return 0;
if (ask(ctx, _("Ignore error"), 1)) {
if (ask(ctx, _("Force rewrite"), 1))
io_channel_write_blk64(channel, block, count, data);
return 0;
}
return error;
}
static errcode_t e2fsck_handle_write_error(io_channel channel,
unsigned long block,
int count,
const void *data,
size_t size EXT2FS_ATTR((unused)),
int actual EXT2FS_ATTR((unused)),
errcode_t error)
{
int i;
const char *p;
ext2_filsys fs = (ext2_filsys) channel->app_data;
e2fsck_t ctx;
ctx = (e2fsck_t) fs->priv_data;
if (ctx->flags & E2F_FLAG_EXITING)
return 0;
/*
* If more than one block was written, try writing each block
* separately. We could use the actual bytes read to figure
* out where to start, but we don't bother.
*/
if (count > 1) {
p = (const char *) data;
for (i=0; i < count; i++, p += channel->block_size, block++) {
error = io_channel_write_blk64(channel, block,
1, p);
if (error)
return error;
}
return 0;
}
if (operation)
printf(_("Error writing block %lu (%s) while %s. "), block,
error_message(error), operation);
else
printf(_("Error writing block %lu (%s). "), block,
error_message(error));
preenhalt(ctx);
if (ask(ctx, _("Ignore error"), 1))
return 0;
return error;
}
const char *ehandler_operation(const char *op)
{
const char *ret = operation;
operation = op;
return ret;
}
void ehandler_init(io_channel channel)
{
channel->read_error = e2fsck_handle_read_error;
channel->write_error = e2fsck_handle_write_error;
}