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author | Chuck Lever <chuck.lever@oracle.com> | 2019-02-11 11:25:25 -0500 |
---|---|---|
committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2019-02-14 10:13:49 -0500 |
commit | 02ef04e432babf8fc703104212314e54112ecd2d (patch) | |
tree | 4386362756ae73c0fbe207be07fe5bda86037295 /net/sunrpc/clnt.c | |
parent | cf500bac8fd48b57f38ece890235923d4ed5ee91 (diff) | |
download | linux-stable-02ef04e432babf8fc703104212314e54112ecd2d.tar.gz linux-stable-02ef04e432babf8fc703104212314e54112ecd2d.tar.bz2 linux-stable-02ef04e432babf8fc703104212314e54112ecd2d.zip |
NFS: Account for XDR pad of buf->pages
Certain NFS results (eg. READLINK) might expect a data payload that
is not an exact multiple of 4 bytes. In this case, XDR encoding
is required to pad that payload so its length on the wire is a
multiple of 4 bytes. The constants that define the maximum size of
each NFS result do not appear to account for this extra word.
In each case where the data payload is to be received into pages:
- 1 word is added to the size of the receive buffer allocated by
call_allocate
- rpc_inline_rcv_pages subtracts 1 word from @hdrsize so that the
extra buffer space falls into the rcv_buf's tail iovec
- If buf->pagelen is word-aligned, an XDR pad is not needed and
is thus removed from the tail
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc/clnt.c')
-rw-r--r-- | net/sunrpc/clnt.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index f780605fffe0..4ea38b029e2f 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -1177,7 +1177,11 @@ void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages, unsigned int base, unsigned int len, unsigned int hdrsize) { - hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_rslack; + /* Subtract one to force an extra word of buffer space for the + * payload's XDR pad to fall into the rcv_buf's tail iovec. + */ + hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_rslack - 1; + xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len); trace_rpc_reply_pages(req); } |