From 528b84934eb904ecafea4ed482a1c52e3c814050 Mon Sep 17 00:00:00 2001 From: Anna Schumaker Date: Mon, 28 Sep 2020 13:08:58 -0400 Subject: [PATCH] NFSD: Add READ_PLUS data support 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 Signed-off-by: J. Bruce Fields --- 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 b09334414b98..3dd69b6315c8 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -2590,6 +2590,20 @@ 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; @@ -3162,6 +3176,13 @@ 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 a37828c375ae..206670a20290 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,