rpc: Allow xdr_buf_subsegment to operate in-place (de4aee2e) · Commits · 戴 / test

net/sunrpc/xdr.c

+16 −6

Original line number	Diff line number	Diff line
		@@ -833,8 +833,20 @@ xdr_buf_from_iov(struct kvec iov, struct xdr_buf buf)
		}
		EXPORT_SYMBOL_GPL(xdr_buf_from_iov);

		/* Sets subbuf to the portion of buf of length len beginning base bytes
		* from the start of buf. Returns -1 if base of length are out of bounds. */
		/**
		* xdr_buf_subsegment - set subbuf to a portion of buf
		* @buf: an xdr buffer
		* @subbuf: the result buffer
		* @base: beginning of range in bytes
		* @len: length of range in bytes
		*
		* sets @subbuf to an xdr buffer representing the portion of @buf of
		* length @len starting at offset @base.
		*
		* @buf and @subbuf may be pointers to the same struct xdr_buf.
		*
		* Returns -1 if base of length are out of bounds.
		*/
		int
		xdr_buf_subsegment(struct xdr_buf buf, struct xdr_buf subbuf,
		unsigned int base, unsigned int len)
		@@ -847,9 +859,8 @@ xdr_buf_subsegment(struct xdr_buf buf, struct xdr_buf subbuf,
		len -= subbuf->head[0].iov_len;
		base = 0;
		} else {
		subbuf->head[0].iov_base = NULL;
		subbuf->head[0].iov_len = 0;
		base -= buf->head[0].iov_len;
		subbuf->head[0].iov_len = 0;
		}

		if (base < buf->page_len) {
		@@ -871,9 +882,8 @@ xdr_buf_subsegment(struct xdr_buf buf, struct xdr_buf subbuf,
		len -= subbuf->tail[0].iov_len;
		base = 0;
		} else {
		subbuf->tail[0].iov_base = NULL;
		subbuf->tail[0].iov_len = 0;
		base -= buf->tail[0].iov_len;
		subbuf->tail[0].iov_len = 0;
		}

		if (base \|\| len)