From: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
This patch adds READ_PLUS support for returning a single
NFS4_CONTENT_DATA segment to the client. This is basically the same as
the READ operation, only with the extra information about data segments.
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
---
v6:
- nfsd4_decode_compound() should check if we're doing a read plus so
svc_reserve() can set the right buffer size.
- Fix up nfsd4_read_plus_rsize() calculation to account for possibly
sending two data segments if the file changes during encoding.
- Limit maxcount to the amount of available buffer space
v5: Fix up nfsd4_read_plus_rsize() calculation
---
fs/nfsd/nfs4proc.c | 21 +++++++++++
fs/nfsd/nfs4xdr.c | 87 ++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 105 insertions(+), 3 deletions(-)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index eaf50eafa935..c825a6e6ad4e 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -2591,6 +2591,20 @@ static inline u32 nfsd4_read_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
return (op_encode_hdr_size + 2 + XDR_QUADLEN(rlen)) * sizeof(__be32);
}
+static inline u32 nfsd4_read_plus_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ u32 maxcount = svc_max_payload(rqstp);
+ u32 rlen = min(op->u.read.rd_length, maxcount);
+ /*
+ * If we detect that the file changed during hole encoding, then we
+ * recover by encoding the remaining reply as data. This means we need
+ * to set aside enough room to encode two data segments.
+ */
+ u32 seg_len = 2 * (1 + 2 + 1);
+
+ return (op_encode_hdr_size + 2 + seg_len + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
static inline u32 nfsd4_readdir_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
u32 maxcount = 0, rlen = 0;
@@ -3163,6 +3177,13 @@ static const struct nfsd4_operation nfsd4_ops[] = {
.op_name = "OP_COPY",
.op_rsize_bop = nfsd4_copy_rsize,
},
+ [OP_READ_PLUS] = {
+ .op_func = nfsd4_read,
+ .op_release = nfsd4_read_release,
+ .op_name = "OP_READ_PLUS",
+ .op_rsize_bop = nfsd4_read_plus_rsize,
+ .op_get_currentstateid = nfsd4_get_readstateid,
+ },
[OP_SEEK] = {
.op_func = nfsd4_seek,
.op_name = "OP_SEEK",
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 0be194de4888..477a7d8bb9a4 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2173,7 +2173,7 @@ static const nfsd4_dec nfsd4_dec_ops[] = {
[OP_LAYOUTSTATS] = (nfsd4_dec)nfsd4_decode_notsupp,
[OP_OFFLOAD_CANCEL] = (nfsd4_dec)nfsd4_decode_offload_status,
[OP_OFFLOAD_STATUS] = (nfsd4_dec)nfsd4_decode_offload_status,
- [OP_READ_PLUS] = (nfsd4_dec)nfsd4_decode_notsupp,
+ [OP_READ_PLUS] = (nfsd4_dec)nfsd4_decode_read,
[OP_SEEK] = (nfsd4_dec)nfsd4_decode_seek,
[OP_WRITE_SAME] = (nfsd4_dec)nfsd4_decode_notsupp,
[OP_CLONE] = (nfsd4_dec)nfsd4_decode_clone,
@@ -2261,7 +2261,7 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
*/
cachethis |= nfsd4_cache_this_op(op);
- if (op->opnum == OP_READ) {
+ if (op->opnum == OP_READ || op->opnum == OP_READ_PLUS) {
readcount++;
readbytes += nfsd4_max_reply(argp->rqstp, op);
} else
@@ -4597,6 +4597,87 @@ nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
return nfserr_resource;
p = xdr_encode_hyper(p, os->count);
*p++ = cpu_to_be32(0);
+ return nfserr;
+}
+
+static __be32
+nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
+ struct nfsd4_read *read,
+ unsigned long maxcount, u32 *eof)
+{
+ struct xdr_stream *xdr = &resp->xdr;
+ struct file *file = read->rd_nf->nf_file;
+ int starting_len = xdr->buf->len;
+ __be32 nfserr;
+ __be32 *p, tmp;
+ __be64 tmp64;
+
+ maxcount = min_t(unsigned long, maxcount, (xdr->buf->buflen - xdr->buf->len));
+
+ /* Content type, offset, byte count */
+ p = xdr_reserve_space(xdr, 4 + 8 + 4);
+ if (!p)
+ return nfserr_resource;
+
+ read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, maxcount);
+ if (read->rd_vlen < 0)
+ return nfserr_resource;
+
+ nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
+ resp->rqstp->rq_vec, read->rd_vlen, &maxcount, eof);
+ if (nfserr)
+ return nfserr;
+
+ tmp = htonl(NFS4_CONTENT_DATA);
+ write_bytes_to_xdr_buf(xdr->buf, starting_len, &tmp, 4);
+ tmp64 = cpu_to_be64(read->rd_offset);
+ write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp64, 8);
+ tmp = htonl(maxcount);
+ write_bytes_to_xdr_buf(xdr->buf, starting_len + 12, &tmp, 4);
+ return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
+ struct nfsd4_read *read)
+{
+ unsigned long maxcount;
+ struct xdr_stream *xdr = &resp->xdr;
+ struct file *file;
+ int starting_len = xdr->buf->len;
+ int segments = 0;
+ __be32 *p, tmp;
+ u32 eof;
+
+ if (nfserr)
+ return nfserr;
+ file = read->rd_nf->nf_file;
+
+ /* eof flag, segment count */
+ p = xdr_reserve_space(xdr, 4 + 4);
+ if (!p)
+ return nfserr_resource;
+ xdr_commit_encode(xdr);
+
+ maxcount = svc_max_payload(resp->rqstp);
+ maxcount = min_t(unsigned long, maxcount,
+ (xdr->buf->buflen - xdr->buf->len));
+ maxcount = min_t(unsigned long, maxcount, read->rd_length);
+
+ eof = read->rd_offset >= i_size_read(file_inode(file));
+ if (!eof) {
+ nfserr = nfsd4_encode_read_plus_data(resp, read, maxcount, &eof);
+ segments++;
+ }
+
+ if (nfserr)
+ xdr_truncate_encode(xdr, starting_len);
+ else {
+ tmp = htonl(eof);
+ write_bytes_to_xdr_buf(xdr->buf, starting_len, &tmp, 4);
+ tmp = htonl(segments);
+ write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
+ }
return nfserr;
}
@@ -4974,7 +5055,7 @@ static const nfsd4_enc nfsd4_enc_ops[] = {
[OP_LAYOUTSTATS] = (nfsd4_enc)nfsd4_encode_noop,
[OP_OFFLOAD_CANCEL] = (nfsd4_enc)nfsd4_encode_noop,
[OP_OFFLOAD_STATUS] = (nfsd4_enc)nfsd4_encode_offload_status,
- [OP_READ_PLUS] = (nfsd4_enc)nfsd4_encode_noop,
+ [OP_READ_PLUS] = (nfsd4_enc)nfsd4_encode_read_plus,
[OP_SEEK] = (nfsd4_enc)nfsd4_encode_seek,
[OP_WRITE_SAME] = (nfsd4_enc)nfsd4_encode_noop,
[OP_CLONE] = (nfsd4_enc)nfsd4_encode_noop,
--
2.28.0
