diff options
| author | Chuck Lever <chuck.lever@oracle.com> | 2022-04-01 17:08:21 -0400 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2022-04-06 14:01:27 -0400 |
| commit | 773f91b2cf3f52df0d7508fdbf60f37567cdaee4 (patch) | |
| tree | 09fbe39e6553910ebedee2ecd627cd264fb5f363 /include/linux | |
| parent | 999397926ab3f78c7d1235cc4ca6e3c89d2769bf (diff) | |
SUNRPC: Fix NFSD's request deferral on RDMA transports
Trond Myklebust reports an NFSD crash in svc_rdma_sendto(). Further
investigation shows that the crash occurred while NFSD was handling
a deferred request.
This patch addresses two inter-related issues that prevent request
deferral from working correctly for RPC/RDMA requests:
1. Prevent the crash by ensuring that the original
svc_rqst::rq_xprt_ctxt value is available when the request is
revisited. Otherwise svc_rdma_sendto() does not have a Receive
context available with which to construct its reply.
2. Possibly since before commit 71641d99ce03 ("svcrdma: Properly
compute .len and .buflen for received RPC Calls"),
svc_rdma_recvfrom() did not include the transport header in the
returned xdr_buf. There should have been no need for svc_defer()
and friends to save and restore that header, as of that commit.
This issue is addressed in a backport-friendly way by simply
having svc_rdma_recvfrom() set rq_xprt_hlen to zero
unconditionally, just as svc_tcp_recvfrom() does. This enables
svc_deferred_recv() to correctly reconstruct an RPC message
received via RPC/RDMA.
Reported-by: Trond Myklebust <trondmy@hammerspace.com>
Link: https://lore.kernel.org/linux-nfs/82662b7190f26fb304eb0ab1bb04279072439d4e.camel@hammerspace.com/
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/sunrpc/svc.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index a5dda4987e8b..217711fc9cac 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -395,6 +395,7 @@ struct svc_deferred_req { size_t addrlen; struct sockaddr_storage daddr; /* where reply must come from */ size_t daddrlen; + void *xprt_ctxt; struct cache_deferred_req handle; size_t xprt_hlen; int argslen; |