From: Jeff Layton <jlayton@kernel.org>
To: tytso@mit.edu, adilger.kernel@dilger.ca
Cc: linux-ext4@vger.kernel.org,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
lczerner@redhat.com, Benjamin Coddington <bcodding@redhat.com>
Subject: should we make "-o iversion" the default on ext4 ?
Date: Tue, 19 Jul 2022 09:51:33 -0400 [thread overview]
Message-ID: <69ac1d3ef0f63b309204a570ef4922d2684ed7f9.camel@kernel.org> (raw)
Back in 2018, I did a patchset [1] to rework the inode->i_version
counter handling to be much less expensive, particularly when no-one is
querying for it.
Testing at the time showed that the cost of enabling i_version on ext4
was close to 0 when nothing is querying it, but I stopped short of
trying to make it the default at the time (mostly out of an abundance of
caution). Since then, we still see a steady stream of cache-coherency
problems with NFSv4 on ext4 when this option is disabled (e.g. [2]).
Is it time to go ahead and make this option the default on ext4? I don't
see a real downside to doing so, though I'm unclear on how we should
approach this. Currently the option is twiddled using MS_I_VERSION flag,
and it's unclear to me how we can reverse the sense of such a flag.
Thoughts?
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a4b7fd7d34de5765dece2dd08060d2e1f7be3b39
[2]: https://bugzilla.redhat.com/show_bug.cgi?id=2107587
--
Jeff Layton <jlayton@kernel.org>
next reply other threads:[~2022-07-19 14:18 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-19 13:51 Jeff Layton [this message]
2022-07-20 14:15 ` should we make "-o iversion" the default on ext4 ? Lukas Czerner
2022-07-20 14:38 ` Jeff Layton
2022-07-20 15:22 ` Lukas Czerner
2022-07-20 16:42 ` Jeff Layton
2022-07-21 14:06 ` Lukas Czerner
2022-07-21 17:03 ` Jeff Layton
2022-07-20 15:56 ` Benjamin Coddington
2022-07-20 16:06 ` Christoph Hellwig
2022-07-20 16:15 ` Jeff Layton
2022-07-20 16:29 ` Benjamin Coddington
2022-07-20 16:46 ` Jeff Layton
2022-07-21 22:32 ` Dave Chinner
2022-07-25 16:22 ` Jeff Layton
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