linux-ext4 - Re: [PATCH] mke2fs: restore verbose message for BLKDISCARD

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: <20130308190019.GB12008@thunk.org>
Date:	Fri, 8 Mar 2013 14:00:19 -0500
From:	Theodore Ts'o <tytso@....edu>
To:	Stephen Warren <swarren@...dotorg.org>
Cc:	Lukáš Czerner <lczerner@...hat.com>,
	Chris Ball <cjb@...top.org>, linux-ext4@...r.kernel.org,
	Stephen Warren <swarren@...dia.com>
Subject: Re: [PATCH] mke2fs: restore verbose message for BLKDISCARD

I hate to suggest this, but there's so many crappy devices out there
that I'm wondering if we need to figure out some way of maintaining a
black list of devices that don't handle discard properly.  For
example, the Sandisk U100 advertises a max discard granularity of 512
bytes, but I've been advised that if you don't use a discard
granularity of 256k, aligned on 256k, you'll be very, very, sorry.

It sounds like Stephen's device is probably an example of Yet Another
Busted Trim implementation.  The problem is that manufacturers will be
releasing more broken products faster than we can update a blacklist
in the kernel.  So any blacklist would have to be maintained online on
the web, and dynamically updated by distro installers.   :-(

    	     		 	    	   		 - Ted
--
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