diff options
| -rw-r--r-- | fs/nfsd/nfs4xdr.c | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index b2243b5dbf18..2399b17db052 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -4318,6 +4318,15 @@ static __be32 nfsd4_encode_splice_read( __be32 nfserr; /* + * Splice read doesn't work if encoding has already wandered + * into the XDR buf's page array. + */ + if (unlikely(xdr->buf->page_len)) { + WARN_ON_ONCE(1); + return nfserr_serverfault; + } + + /* * Make sure there is room at the end of buf->head for * svcxdr_encode_opaque_pages() to create a tail buffer * to XDR-pad the payload. @@ -4399,25 +4408,23 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_compoundargs *argp = resp->rqstp->rq_argp; struct nfsd4_read *read = &u->read; struct xdr_stream *xdr = resp->xdr; - int starting_len = xdr->buf->len; bool splice_ok = argp->splice_ok; + unsigned int eof_offset; unsigned long maxcount; + __be32 wire_data[2]; struct file *file; - __be32 *p; if (nfserr) return nfserr; + + eof_offset = xdr->buf->len; file = read->rd_nf->nf_file; - p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */ - if (!p) { + /* Reserve space for the eof flag and byte count */ + if (unlikely(!xdr_reserve_space(xdr, XDR_UNIT * 2))) { WARN_ON_ONCE(splice_ok); return nfserr_resource; } - if (resp->xdr->buf->page_len && splice_ok) { - WARN_ON_ONCE(1); - return nfserr_serverfault; - } xdr_commit_encode(xdr); maxcount = min_t(unsigned long, read->rd_length, @@ -4428,12 +4435,13 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr, else nfserr = nfsd4_encode_readv(resp, read, file, maxcount); if (nfserr) { - xdr_truncate_encode(xdr, starting_len); + xdr_truncate_encode(xdr, eof_offset); return nfserr; } - p = xdr_encode_bool(p, read->rd_eof); - *p = cpu_to_be32(read->rd_length); + wire_data[0] = read->rd_eof ? xdr_one : xdr_zero; + wire_data[1] = cpu_to_be32(read->rd_length); + write_bytes_to_xdr_buf(xdr->buf, eof_offset, &wire_data, XDR_UNIT * 2); return nfs_ok; } @@ -5304,10 +5312,6 @@ nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp, p = xdr_reserve_space(xdr, 4 + 8 + 4); if (!p) return nfserr_io; - if (resp->xdr->buf->page_len && splice_ok) { - WARN_ON_ONCE(splice_ok); - return nfserr_serverfault; - } maxcount = min_t(unsigned long, read->rd_length, (xdr->buf->buflen - xdr->buf->len)); |