Messages in this thread Patch in this message | | | From | Jiri Slaby <> | Subject | [PATCH 3.12 67/78] SUNRPC: Fix large reads on NFS/RDMA | Date | Fri, 22 Apr 2016 13:05:50 +0200 |
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From: Chuck Lever <chuck.lever@oracle.com>
3.12-stable review patch. If anyone has any objections, please let me know.
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commit 2b7bbc963da8d076f263574af4138b5df2e1581f upstream.
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> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- net/sunrpc/xprtrdma/rpc_rdma.c | 4 +--- 1 file changed, 1 insertion(+), 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; -- 2.8.1
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