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From:   schumaker.anna@gmail.com
To:     bfields@redhat.com, linux-nfs@vger.kernel.org
Cc:     Anna.Schumaker@Netapp.com
Subject: [PATCH v2 1/4] NFSD: Return eof and maxcount to nfsd4_encode_read()
Date:   Fri, 14 Feb 2020 16:12:03 -0500
Message-Id: <20200214211206.407725-2-Anna.Schumaker@Netapp.com>
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From: Anna Schumaker <Anna.Schumaker@Netapp.com>

I want to reuse nfsd4_encode_readv() and nfsd4_encode_splice_read() in
READ_PLUS rather than reimplementing them. READ_PLUS returns a single
eof flag for the entire call and a separate maxcount for each data
segment, so we need to have the READ call encode these values in a
different place.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
---
 fs/nfsd/nfs4xdr.c | 60 ++++++++++++++++++++---------------------------
 1 file changed, 26 insertions(+), 34 deletions(-)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 9761512674a0..45f0623f6488 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3521,23 +3521,22 @@ nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr, struc
 
 static __be32 nfsd4_encode_splice_read(
 				struct nfsd4_compoundres *resp,
-				struct nfsd4_read *read,
-				struct file *file, unsigned long maxcount)
+				struct nfsd4_read *read, struct file *file,
+				unsigned long *maxcount, u32 *eof)
 {
 	struct xdr_stream *xdr = &resp->xdr;
 	struct xdr_buf *buf = xdr->buf;
-	u32 eof;
+	long len;
 	int space_left;
 	__be32 nfserr;
-	__be32 *p = xdr->p - 2;
 
 	/* Make sure there will be room for padding if needed */
 	if (xdr->end - xdr->p < 1)
 		return nfserr_resource;
 
+	len = *maxcount;
 	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
-				  file, read->rd_offset, &maxcount, &eof);
-	read->rd_length = maxcount;
+				  file, read->rd_offset, maxcount, eof);
 	if (nfserr) {
 		/*
 		 * nfsd_splice_actor may have already messed with the
@@ -3548,24 +3547,21 @@ static __be32 nfsd4_encode_splice_read(
 		return nfserr;
 	}
 
-	*(p++) = htonl(eof);
-	*(p++) = htonl(maxcount);
-
-	buf->page_len = maxcount;
-	buf->len += maxcount;
-	xdr->page_ptr += (buf->page_base + maxcount + PAGE_SIZE - 1)
+	buf->page_len = *maxcount;
+	buf->len += *maxcount;
+	xdr->page_ptr += (buf->page_base + *maxcount + PAGE_SIZE - 1)
 							/ PAGE_SIZE;
 
 	/* Use rest of head for padding and remaining ops: */
 	buf->tail[0].iov_base = xdr->p;
 	buf->tail[0].iov_len = 0;
 	xdr->iov = buf->tail;
-	if (maxcount&3) {
-		int pad = 4 - (maxcount&3);
+	if (*maxcount&3) {
+		int pad = 4 - (*maxcount&3);
 
 		*(xdr->p++) = 0;
 
-		buf->tail[0].iov_base += maxcount&3;
+		buf->tail[0].iov_base += *maxcount&3;
 		buf->tail[0].iov_len = pad;
 		buf->len += pad;
 	}
@@ -3579,22 +3575,20 @@ static __be32 nfsd4_encode_splice_read(
 }
 
 static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
-				 struct nfsd4_read *read,
-				 struct file *file, unsigned long maxcount)
+				 struct nfsd4_read *read, struct file *file,
+				 unsigned long *maxcount, u32 *eof)
 {
 	struct xdr_stream *xdr = &resp->xdr;
-	u32 eof;
 	int v;
 	int starting_len = xdr->buf->len - 8;
 	long len;
 	int thislen;
 	__be32 nfserr;
-	__be32 tmp;
 	__be32 *p;
 	u32 zzz = 0;
 	int pad;
 
-	len = maxcount;
+	len = *maxcount;
 	v = 0;
 
 	thislen = min_t(long, len, ((void *)xdr->end - (void *)xdr->p));
@@ -3616,22 +3610,15 @@ static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
 	}
 	read->rd_vlen = v;
 
-	len = maxcount;
+	len = *maxcount;
 	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
-			    resp->rqstp->rq_vec, read->rd_vlen, &maxcount,
-			    &eof);
-	read->rd_length = maxcount;
+			    resp->rqstp->rq_vec, read->rd_vlen, maxcount, eof);
 	if (nfserr)
 		return nfserr;
-	xdr_truncate_encode(xdr, starting_len + 8 + ((maxcount+3)&~3));
+	xdr_truncate_encode(xdr, starting_len + 8 + ((*maxcount+3)&~3));
 
-	tmp = htonl(eof);
-	write_bytes_to_xdr_buf(xdr->buf, starting_len    , &tmp, 4);
-	tmp = htonl(maxcount);
-	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
-
-	pad = (maxcount&3) ? 4 - (maxcount&3) : 0;
-	write_bytes_to_xdr_buf(xdr->buf, starting_len + 8 + maxcount,
+	pad = (*maxcount&3) ? 4 - (*maxcount&3) : 0;
+	write_bytes_to_xdr_buf(xdr->buf, starting_len + 8 + *maxcount,
 								&zzz, pad);
 	return 0;
 
@@ -3642,6 +3629,7 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
 		  struct nfsd4_read *read)
 {
 	unsigned long maxcount;
+	u32 eof;
 	struct xdr_stream *xdr = &resp->xdr;
 	struct file *file;
 	int starting_len = xdr->buf->len;
@@ -3670,13 +3658,17 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
 
 	if (file->f_op->splice_read &&
 	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags))
-		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
+		nfserr = nfsd4_encode_splice_read(resp, read, file, &maxcount, &eof);
 	else
-		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
+		nfserr = nfsd4_encode_readv(resp, read, file, &maxcount, &eof);
 
 	if (nfserr)
 		xdr_truncate_encode(xdr, starting_len);
 
+	read->rd_length = maxcount;
+	*p++ = htonl(eof);
+	*p++ = htonl(maxcount);
+
 	return nfserr;
 }
 
-- 
2.25.0