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| author | Chuck Lever <chuck.lever@oracle.com> | 2016-05-02 21:41:05 +0300 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2016-05-17 22:47:58 +0300 |
| commit | 302d3deb20682a076e1ab551821cacfdc81c5e4f (patch) | |
| tree | f379f2c56120ba7d6f970306d4520c4cc5517726 /net/sunrpc/xprtrdma/fmr_ops.c | |
| parent | 949317464bc2baca0ccc69e35a7b5cd3715633a6 (diff) | |
| download | linux-302d3deb20682a076e1ab551821cacfdc81c5e4f.tar.xz | |
xprtrdma: Prevent inline overflow
When deciding whether to send a Call inline, rpcrdma_marshal_req
doesn't take into account header bytes consumed by chunk lists.
This results in Call messages on the wire that are sometimes larger
than the inline threshold.
Likewise, when a Write list or Reply chunk is in play, the server's
reply has to emit an RDMA Send that includes a larger-than-minimal
RPC-over-RDMA header.
The actual size of a Call message cannot be estimated until after
the chunk lists have been registered. Thus the size of each
RPC-over-RDMA header can be estimated only after chunks are
registered; but the decision to register chunks is based on the size
of that header. Chicken, meet egg.
The best a client can do is estimate header size based on the
largest header that might occur, and then ensure that inline content
is always smaller than that.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc/xprtrdma/fmr_ops.c')
| -rw-r--r-- | net/sunrpc/xprtrdma/fmr_ops.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c index 4aeb104d0696..009694b0c56e 100644 --- a/net/sunrpc/xprtrdma/fmr_ops.c +++ b/net/sunrpc/xprtrdma/fmr_ops.c @@ -39,6 +39,9 @@ static int fmr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep, struct rpcrdma_create_data_internal *cdata) { + rpcrdma_set_max_header_sizes(ia, cdata, max_t(unsigned int, 1, + RPCRDMA_MAX_DATA_SEGS / + RPCRDMA_MAX_FMR_SGES)); return 0; } |