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authorBenjamin Coddington <bcodding@redhat.com>2022-12-16 07:45:27 -0500
committerJakub Kicinski <kuba@kernel.org>2022-12-19 17:28:49 -0800
commit98123866fcf3fe95a0c1b198ef122dfdbd351916 (patch)
treebe2cbfb90c15868dfd2f3b29216109733055299b /net/9p
parentfb87bd47516d9a26b6d549231aa743b20fd4a569 (diff)
Treewide: Stop corrupting socket's task_frag
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 <philipp.reisner@linbit.com> CC: Lars Ellenberg <lars.ellenberg@linbit.com> CC: "Christoph Böhmwalder" <christoph.boehmwalder@linbit.com> CC: Jens Axboe <axboe@kernel.dk> CC: Josef Bacik <josef@toxicpanda.com> CC: Keith Busch <kbusch@kernel.org> CC: Christoph Hellwig <hch@lst.de> CC: Sagi Grimberg <sagi@grimberg.me> CC: Lee Duncan <lduncan@suse.com> CC: Chris Leech <cleech@redhat.com> CC: Mike Christie <michael.christie@oracle.com> CC: "James E.J. Bottomley" <jejb@linux.ibm.com> CC: "Martin K. Petersen" <martin.petersen@oracle.com> CC: Valentina Manea <valentina.manea.m@gmail.com> CC: Shuah Khan <shuah@kernel.org> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: David Howells <dhowells@redhat.com> CC: Marc Dionne <marc.dionne@auristor.com> CC: Steve French <sfrench@samba.org> CC: Christine Caulfield <ccaulfie@redhat.com> CC: David Teigland <teigland@redhat.com> CC: Mark Fasheh <mark@fasheh.com> CC: Joel Becker <jlbec@evilplan.org> CC: Joseph Qi <joseph.qi@linux.alibaba.com> CC: Eric Van Hensbergen <ericvh@gmail.com> CC: Latchesar Ionkov <lucho@ionkov.net> CC: Dominique Martinet <asmadeus@codewreck.org> CC: Ilya Dryomov <idryomov@gmail.com> CC: Xiubo Li <xiubli@redhat.com> CC: Chuck Lever <chuck.lever@oracle.com> CC: Jeff Layton <jlayton@kernel.org> CC: Trond Myklebust <trond.myklebust@hammerspace.com> CC: Anna Schumaker <anna@kernel.org> CC: Steffen Klassert <steffen.klassert@secunet.com> CC: Herbert Xu <herbert@gondor.apana.org.au> Suggested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/9p')
-rw-r--r--net/9p/trans_fd.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 07db2f436d44..d9120f14684b 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -868,6 +868,7 @@ static int p9_socket_open(struct p9_client *client, struct socket *csocket)
}
csocket->sk->sk_allocation = GFP_NOIO;
+ csocket->sk->sk_use_task_frag = false;
file = sock_alloc_file(csocket, 0, NULL);
if (IS_ERR(file)) {
pr_err("%s (%d): failed to map fd\n",