linux-ext4 - Re: Updated patches for journal checksums.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 19 Jun 2007 13:10:53 +0400
From:	Alex Tomas <alex@...sterfs.com>
To:	Andreas Dilger <adilger@...sterfs.com>
CC:	Girish Shilamkar <girish@...sterfs.com>,
	Ext4 Mailing List <linux-ext4@...r.kernel.org>,
	Theodore Tso <tytso@....edu>
Subject: Re: Updated patches for journal checksums.

Andreas Dilger wrote:
> I _think_ Alex is asking "what happens if during a transaction undergoing
> checkpoint of blocks to filesystem (not the last one in the journal) is
> interrupted by a crash and upon restart the partially-checkpointed
> transaction is found to have a checksum error?"

yup, thanks for clarification.

>>> what do we do if transaction in the journal is found with wrong
>>> checksum? leave partial transaction in-place?
>> The sanity of the transaction is checked in PASS_SCAN. And if checksum
>> is found to be incorrect for nth transaction then last transaction which
>> is written to disk is (n - 1).
> 
> The recovery.c code (AFAIK) does not do replay for any transaction that
> does not have a valid checksum, or transactions beyond that.  If the
> bad transaction had already started chekpoint (i.e. isn't the last
> committed transaction) then the journal _should_ return an error up to
> the filesystem, so it can call ext4_error() at startup.  For e2fsck
> (which normally does journal replay & recovery) it can do a full
> filesystem check at this point.

hmm. it actually can be last transaction (following no activity?)

thanks, Alex


-
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html