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author | Chuck Lever <chuck.lever@oracle.com> | 2014-03-12 17:51:30 +0100 |
---|---|---|
committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2014-03-17 20:30:38 +0100 |
commit | 2b7bbc963da8d076f263574af4138b5df2e1581f (patch) | |
tree | b9cc2e05eb59dc9dc6e874cf228171e8b72d013b /net/sunrpc/xprtrdma | |
parent | NFS: Clean up: revert increase in READDIR RPC buffer max size (diff) | |
download | linux-2b7bbc963da8d076f263574af4138b5df2e1581f.tar.xz linux-2b7bbc963da8d076f263574af4138b5df2e1581f.zip |
SUNRPC: Fix large reads on NFS/RDMA
After commit a11a2bf4, "SUNRPC: Optimise away unnecessary data moves
in xdr_align_pages", Thu Aug 2 13:21:43 2012, READs larger than a
few hundred bytes via NFS/RDMA no longer work. This commit exposed
a long-standing bug in rpcrdma_inline_fixup().
I reproduce this with an rsize=4096 mount using the cthon04 basic
tests. Test 5 fails with an EIO error.
For my reproducer, kernel log shows:
NFS: server cheating in read reply: count 4096 > recvd 0
rpcrdma_inline_fixup() is zeroing the xdr_stream::page_len field,
and xdr_align_pages() is now returning that value to the READ XDR
decoder function.
That field is set up by xdr_inline_pages() by the READ XDR encoder
function. As far as I can tell, it is supposed to be left alone
after that, as it describes the dimensions of the reply xdr_stream,
not the contents of that stream.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=68391
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'net/sunrpc/xprtrdma')
-rw-r--r-- | net/sunrpc/xprtrdma/rpc_rdma.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index e03725bfe2b8..96ead526b125 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -649,9 +649,7 @@ rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad) break; page_base = 0; } - rqst->rq_rcv_buf.page_len = olen - copy_len; - } else - rqst->rq_rcv_buf.page_len = 0; + } if (copy_len && rqst->rq_rcv_buf.tail[0].iov_len) { curlen = copy_len; |