On Mon, 2022-11-21 at 08:35 -0500, Benjamin Coddington wrote:
> Since moving to memalloc_nofs_save/restore, SUNRPC has stopped setting the
> GFP_NOIO flag on sk_allocation which the networking system uses to decide
> when it is safe to use current->task_frag. The results of this are
> unexpected corruption in task_frag when SUNRPC is involved in memory
> reclaim.
>
> The corruption can be seen in crashes, but the root cause is often
> difficult to ascertain as a crashing machine's stack trace will have no
> evidence of being near NFS or SUNRPC code. I believe this problem to
> be much more pervasive than reports to the community may indicate.
>
> Fix this by having kernel users of sockets that may corrupt task_frag due
> to reclaim set sk_use_task_frag = false. Preemptively correcting this
> situation for users that still set sk_allocation allows them to convert to
> memalloc_nofs_save/restore without the same unexpected corruptions that are
> sure to follow, unlikely to show up in testing, and difficult to bisect.
>
> CC: Philipp Reisner
> CC: Lars Ellenberg
> CC: "Christoph Böhmwalder"
> CC: Jens Axboe
> CC: Josef Bacik
> CC: Keith Busch
> CC: Christoph Hellwig
> CC: Sagi Grimberg
> CC: Lee Duncan
> CC: Chris Leech
> CC: Mike Christie
> CC: "James E.J. Bottomley"
> CC: "Martin K. Petersen"
> CC: Valentina Manea
> CC: Shuah Khan
> CC: Greg Kroah-Hartman
> CC: David Howells
> CC: Marc Dionne
> CC: Steve French
> CC: Christine Caulfield
> CC: David Teigland
> CC: Mark Fasheh
> CC: Joel Becker
> CC: Joseph Qi
> CC: Eric Van Hensbergen
> CC: Latchesar Ionkov
> CC: Dominique Martinet
> CC: "David S. Miller"
> CC: Eric Dumazet
> CC: Jakub Kicinski
> CC: Paolo Abeni
> CC: Ilya Dryomov
> CC: Xiubo Li
> CC: Chuck Lever
> CC: Jeff Layton
> CC: Trond Myklebust
> CC: Anna Schumaker
> CC: drbd-...@lists.linbit.com
> CC: linux-bl...@vger.kernel.org
> CC: linux-ker...@vger.kernel.org
> CC: n...@other.debian.org
> CC: linux-n...@lists.infradead.org
> CC: open-iscsi@googlegroups.com
> CC: linux-s...@vger.kernel.org
> CC: linux-...@vger.kernel.org
> CC: linux-...@lists.infradead.org
> CC: linux-c...@vger.kernel.org
> CC: samba-techni...@lists.samba.org
> CC: cluster-de...@redhat.com
> CC: ocfs2-de...@oss.oracle.com
> CC: v9fs-develo...@lists.sourceforge.net
> CC: net...@vger.kernel.org
> CC: ceph-de...@vger.kernel.org
> CC: linux-...@vger.kernel.org
>
> Suggested-by: Guillaume Nault
> Signed-off-by: Benjamin Coddington
I think this is the most feasible way out of the existing issue, and I
think this patchset should go via the networking tree, targeting the
Linux 6.2.
If someone has disagreement with the above, please speak!
Thanks,
Paolo
--
You received this message because you are subscribed to the Google Groups
"open-iscsi" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to open-iscsi+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/open-iscsi/d220402a232e204676d9100d6fe4c2ae08f753ee.camel%40redhat.com.
