[PATCH 1/3] NFSv4: Fix the alignment of page data in the getdeviceinfo reply

[trondmy@kernel.org]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

We can fit the device_addr4 opaque data padding in the pages.

Fixes: cf500bac8fd4 ("SUNRPC: Introduce rpc_prepare_reply_pages()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/nfs4xdr.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index c6dbfcae7517..c8714381d511 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3009,15 +3009,19 @@ static void nfs4_xdr_enc_getdeviceinfo(struct rpc_rqst *req,
 	struct compound_hdr hdr = {
 		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
 	};
+	uint32_t replen;
 
 	encode_compound_hdr(xdr, req, &hdr);
 	encode_sequence(xdr, &args->seq_args, &hdr);
+
+	replen = hdr.replen + op_decode_hdr_maxsz;
+
 	encode_getdeviceinfo(xdr, args, &hdr);
 
-	/* set up reply kvec. Subtract notification bitmap max size (2)
-	 * so that notification bitmap is put in xdr_buf tail */
+	/* set up reply kvec. device_addr4 opaque data is read into the
+	 * pages */
 	rpc_prepare_reply_pages(req, args->pdev->pages, args->pdev->pgbase,
-				args->pdev->pglen, hdr.replen - 2);
+				args->pdev->pglen, replen + 2);
 	encode_nops(&hdr);
 }
 
@@ -5848,7 +5852,9 @@ static int decode_getdeviceinfo(struct xdr_stream *xdr,
 	 * and places the remaining xdr data in xdr_buf->tail
 	 */
 	pdev->mincount = be32_to_cpup(p);
-	if (xdr_read_pages(xdr, pdev->mincount) != pdev->mincount)
+	/* Calculate padding */
+	len = xdr_align_size(pdev->mincount);
+	if (xdr_read_pages(xdr, len) != len)
 		return -EIO;
 
 	/* Parse notification bitmap, verifying that it is zero. */
-- 
2.28.0