linux-ext4 - e2fsck aborts when invalid indirect block is encountered

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Date:	Thu, 1 Sep 2011 14:34:10 +0800
From:	Chen Huan <chenhuan@...hpc.ac.cn>
To:	linux-ext4@...r.kernel.org
Subject: e2fsck aborts when invalid indirect block is encountered

Hi, All.

During a recent read-only checking of an corrupted ext3 file system,
I found a strange behaviour of e2fsck: when an inode has an invalid
indirect block number, e2fsck aborts with the following message:

    e2fsck 1.39 (29-May-2006)
    Pass 1: Checking inodes, blocks, and sizes
    Inode 12 has illegal block(s).  Clear? no

    Illegal block #-1 (4294967295) in inode 12.  IGNORED.
    Error while iterating over blocks in inode 12: Illegal indirect block found
    e2fsck: aborted

You can reproduce it with this code snippet:

    #!/bin/sh

    dev=/dev/sde
    mnt=/mnt

    mkfs.ext3 -F $dev
    mount $dev $mnt
    dd if=/dev/zero of=$mnt/file bs=1M count=1
    umount $dev
    debugfs -w -R 'sif file block[IND] 0xFFFFFFFF' $dev
    e2fsck -f -n $dev

Doing a fixing without -n option can safely delete this bad blocknum.

My question is: Is this behaviour a bug or intended?
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