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| author | Chuck Lever <chuck.lever@oracle.com> | 2022-04-02 00:08:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-20 10:34:18 +0300 |
| commit | f5e13d700a4d40ccde3d36e383f9247dcb3c1d2d (patch) | |
| tree | 85bc30bd70d33587ff998cd1139bdd39ed19c8a4 /include | |
| parent | 00715427ea778b45a6d2bf2c20bbdff33b44d3f6 (diff) | |
| download | linux-f5e13d700a4d40ccde3d36e383f9247dcb3c1d2d.tar.xz | |
SUNRPC: Fix NFSD's request deferral on RDMA transports
commit 773f91b2cf3f52df0d7508fdbf60f37567cdaee4 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -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 6263410c948a..01f09adccc63 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -384,6 +384,7 @@ 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; |