linux-ext4 - Re: [Bug 207367] Accraid / aptec / Microsemi / ext4 / larger then 16TB

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]

Message-ID: <20200421080405.GA4149@infradead.org>
Date:   Tue, 21 Apr 2020 01:04:05 -0700
From:   Christoph Hellwig <hch@...radead.org>
To:     Dave Chinner <david@...morbit.com>
Cc:     Ritesh Harjani <riteshh@...ux.ibm.com>,
        bugzilla-daemon@...zilla.kernel.org, linux-ext4@...r.kernel.org,
        Theodore Ts'o <tytso@....edu>, Jan Kara <jack@...e.cz>,
        "Darrick J. Wong" <darrick.wong@...cle.com>,
        linux-fsdevel@...r.kernel.org
Subject: Re: [Bug 207367] Accraid / aptec / Microsemi / ext4 / larger then
 16TB

On Tue, Apr 21, 2020 at 03:08:50PM +1000, Dave Chinner wrote:
> > FYI - I do see that bmap() is also used by below APIs/subsystem.
> > Not sure if any of subsystems mentioned below may still fail later
> > if the underlying FS moved to iomap_bmap() interface or for
> > any existing callers of iomap_bmap() :-
> > 
> > 1. mm/page-io.c (generic_swapfile_activate() func)
> 
> Filesystems using iomap infrastructure should be providing
> aops->swap_activate() to map swapfile extents via
> iomap_swapfile_activate() (e.g. see xfs_iomap_swapfile_activate()),
> not using generic_swapfile_activate().

And we also need to eventually phase generic_swapfile_activate out,
maybe by having a version with a get_blocks callback for the non-iomap
case.

> > 4. fs/jbd2/journal.c
> 
> Broken on filesystems where the journal file might be placed beyond
> a 32 bit block number, iomap_bmap() just makes that obvious. Needs
> fixing.

I think this wants to use iomap, as that would solve all the problems.

> And you missed the MD bitmap code uses bmap() to map it's bitmap
> storage file, which means that is broken is the bitmap file is on a
> filesystem/block device > 16TB, too...

This probably needs to use the in-kernel direct I/O interface, just
as it is planned for cachefiles.