Commit 7c4cd5f4 authored by Anna Schumaker's avatar Anna Schumaker Committed by Trond Myklebust
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SUNRPC: Add a function for directly setting the xdr page len 



We need to do this step during READ_PLUS decoding so that we know pages
are the right length and any extra data has been preserved in the tail.

Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 4f5f3b60

include/linux/sunrpc/xdr.h

+1 −0
Original line number Diff line number Diff line
@@ -258,6 +258,7 @@ extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes); 
extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);

extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);

extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);

extern void xdr_set_pagelen(struct xdr_stream *, unsigned int len);

extern unsigned int xdr_align_data(struct xdr_stream *, unsigned int offset, unsigned int length);

extern unsigned int xdr_expand_hole(struct xdr_stream *, unsigned int offset, unsigned int length);

extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,

net/sunrpc/xdr.c

+30 −0
Original line number Diff line number Diff line
@@ -1500,6 +1500,36 @@ unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) 
}

EXPORT_SYMBOL_GPL(xdr_read_pages);



/**

 * xdr_set_pagelen - Sets the length of the XDR pages

 * @xdr: pointer to xdr_stream struct

 * @len: new length of the XDR page data

 *

 * Either grows or shrinks the length of the xdr pages by setting pagelen to

 * @len bytes. When shrinking, any extra data is moved into buf->tail, whereas

 * when growing any data beyond the current pointer is moved into the tail.

 *

 * Returns True if the operation was successful, and False otherwise.

 */

void xdr_set_pagelen(struct xdr_stream *xdr, unsigned int len)

{

	struct xdr_buf *buf = xdr->buf;

	size_t remaining = xdr_stream_remaining(xdr);

	size_t base = 0;



	if (len < buf->page_len) {

		base = buf->page_len - len;

		xdr_shrink_pagelen(buf, len);

	} else {

		xdr_buf_head_shift_right(buf, xdr_stream_pos(xdr),

					 buf->page_len, remaining);

		if (len > buf->page_len)

			xdr_buf_try_expand(buf, len - buf->page_len);

	}

	xdr_set_tail_base(xdr, base, remaining);

}

EXPORT_SYMBOL_GPL(xdr_set_pagelen);



unsigned int xdr_align_data(struct xdr_stream *xdr, unsigned int offset,

			    unsigned int length)

{