From e1bd87608d4b6f87813f79b91e834de610f1049b Mon Sep 17 00:00:00 2001 From: Anna Schumaker Date: Thu, 21 Jul 2022 14:21:33 -0400 Subject: [PATCH] SUNRPC: Add a function for zeroing out a portion of an xdr_stream This will be used during READ_PLUS decoding for handling HOLE segments. Signed-off-by: Anna Schumaker Signed-off-by: Trond Myklebust --- include/linux/sunrpc/xdr.h | 2 ++ net/sunrpc/xdr.c | 23 +++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 8cd38a9994ca..f0ab06acab61 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -265,6 +265,8 @@ extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf unsigned int len); extern unsigned int xdr_stream_move_subsegment(struct xdr_stream *xdr, unsigned int offset, unsigned int target, unsigned int length); +extern unsigned int xdr_stream_zero(struct xdr_stream *xdr, unsigned int offset, + unsigned int length); /** * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data. diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index e4ac700ca554..f09a7ab1a82b 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -1770,6 +1770,29 @@ unsigned int xdr_stream_move_subsegment(struct xdr_stream *xdr, unsigned int off EXPORT_SYMBOL_GPL(xdr_stream_move_subsegment); /** + * xdr_stream_zero - zero out a portion of an xdr_stream + * @xdr: an xdr_stream to zero out + * @offset: the starting point in the stream + * @length: the number of bytes to zero + */ +unsigned int xdr_stream_zero(struct xdr_stream *xdr, unsigned int offset, + unsigned int length) +{ + struct xdr_buf buf; + + if (xdr_buf_subsegment(xdr->buf, &buf, offset, length) < 0) + return 0; + if (buf.head[0].iov_len) + xdr_buf_iov_zero(buf.head, 0, buf.head[0].iov_len); + if (buf.page_len > 0) + xdr_buf_pages_zero(&buf, 0, buf.page_len); + if (buf.tail[0].iov_len) + xdr_buf_iov_zero(buf.tail, 0, buf.tail[0].iov_len); + return length; +} +EXPORT_SYMBOL_GPL(xdr_stream_zero); + +/** * xdr_buf_trim - lop at most "len" bytes off the end of "buf" * @buf: buf to be trimmed * @len: number of bytes to reduce "buf" by -- 2.11.0