From: Anna Schumaker <[email protected]>
The READ_PLUS operation uses a 32-bit length field for encoding a DATA
segment, but 64-bit length field for encoding a HOLE segment. When
setting up our reply buffer, we need to reserve enough space to encode
a HOLE before reading the file data and use this function if the first
segment turns out to be DATA.
Signed-off-by: Anna Schumaker <[email protected]>
---
include/linux/sunrpc/xdr.h | 1 +
net/sunrpc/xdr.c | 17 +++++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index e26047d474b2..bdaf048edde0 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -191,6 +191,7 @@ xdr_adjust_iovec(struct kvec *iov, __be32 *p)
extern void xdr_shift_buf(struct xdr_buf *, size_t);
extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *);
extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
+extern void xdr_buf_trim_head(struct xdr_buf *, unsigned int);
extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
extern int read_bytes_from_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
extern int write_bytes_to_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 63d9cdc989da..37956a274f81 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -1739,6 +1739,23 @@ unsigned int xdr_stream_move_subsegment(struct xdr_stream *xdr, unsigned int off
}
EXPORT_SYMBOL_GPL(xdr_stream_move_subsegment);
+/**
+ * xdr_buf_trim_head - lop at most "len" bytes off the end of "buf"->head
+ * @buf: buf to be trimmed
+ * @len: number of bytes to reduce "buf"->head by
+ *
+ * Trim an xdr_buf->head by the given number of bytes by fixing up the lengths.
+ * Note that it's possible that we'll trim less than that amount if the
+ * xdr_buf->head is too small.
+ */
+void xdr_buf_trim_head(struct xdr_buf *buf, unsigned int len)
+{
+ size_t trim = min_t(size_t, buf->head[0].iov_len, len);
+ buf->head[0].iov_len -= trim;
+ buf->len -= trim;
+}
+EXPORT_SYMBOL_GPL(xdr_buf_trim_head);
+
/**
* xdr_buf_trim - lop at most "len" bytes off the end of "buf"
* @buf: buf to be trimmed
--
2.37.0
Hi Anna,
I love your patch! Perhaps something to improve:
[auto build test WARNING on trondmy-nfs/linux-next]
[also build test WARNING on linus/master v5.19-rc6 next-20220715]
[cannot apply to cel-2.6/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Anna-Schumaker/NFSD-Improvements-for-the-NFSv4-2-READ_PLUS-operation/20220714-030910
base: git://git.linux-nfs.org/projects/trondmy/linux-nfs.git linux-next
reproduce: make htmldocs
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
All warnings (new ones prefixed by >>):
>> Documentation/networking/kapi:59: net/sunrpc/xdr.c:1749: WARNING: Unexpected indentation.
--
0-DAY CI Kernel Test Service
https://01.org/lkp