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| author | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2022-07-21 20:21:32 +0200 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2022-07-23 21:38:29 +0200 |
| commit | 7c4cd5f4d2dd4a028a46bfb696b0cd387caadf33 (patch) | |
| tree | f4598d27c5c81a33cc03256b89e452b8f699e12e | |
| parent | SUNRPC: Introduce xdr_stream_move_subsegment() (diff) | |
| download | linux-7c4cd5f4d2dd4a028a46bfb696b0cd387caadf33.tar.xz linux-7c4cd5f4d2dd4a028a46bfb696b0cd387caadf33.zip | |
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: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
| -rw-r--r-- | include/linux/sunrpc/xdr.h | 1 | ||||
| -rw-r--r-- | net/sunrpc/xdr.c | 30 |
2 files changed, 31 insertions, 0 deletions
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 7dcc6c31fe29..8cd38a9994ca 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -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, diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 8ba11a754297..e4ac700ca554 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -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) { |