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authorChuck Lever <chuck.lever@oracle.com>2020-11-03 19:54:23 +0300
committerChuck Lever <chuck.lever@oracle.com>2020-11-30 22:46:36 +0300
commitc1346a1216ab5cb04a265380ac9035d91b16b6d5 (patch)
treefeb036b9a90fe5770f136e83b356df03e0f78ec5 /net/sunrpc/xdr.c
parent08281341be8ebc97ee47999812bcf411942baa1e (diff)
downloadlinux-c1346a1216ab5cb04a265380ac9035d91b16b6d5.tar.xz
NFSD: Replace the internals of the READ_BUF() macro
Convert the READ_BUF macro in nfs4xdr.c from open code to instead use the new xdr_stream-style decoders already in use by the encode side (and by the in-kernel NFS client implementation). Once this conversion is done, each individual NFSv4 argument decoder can be independently cleaned up to replace these macros with C code. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'net/sunrpc/xdr.c')
-rw-r--r--net/sunrpc/xdr.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index c607744b3ea8..757560a3b06b 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -1408,6 +1408,51 @@ int xdr_buf_subsegment(const struct xdr_buf *buf, struct xdr_buf *subbuf,
EXPORT_SYMBOL_GPL(xdr_buf_subsegment);
/**
+ * xdr_stream_subsegment - set @subbuf to a portion of @xdr
+ * @xdr: an xdr_stream set up for decoding
+ * @subbuf: the result buffer
+ * @nbytes: length of @xdr to extract, in bytes
+ *
+ * Sets up @subbuf to represent a portion of @xdr. The portion
+ * starts at the current offset in @xdr, and extends for a length
+ * of @nbytes. If this is successful, @xdr is advanced to the next
+ * position following that portion.
+ *
+ * Return values:
+ * %true: @subbuf has been initialized, and @xdr has been advanced.
+ * %false: a bounds error has occurred
+ */
+bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
+ unsigned int nbytes)
+{
+ unsigned int remaining, offset, len;
+
+ if (xdr_buf_subsegment(xdr->buf, subbuf, xdr_stream_pos(xdr), nbytes))
+ return false;
+
+ if (subbuf->head[0].iov_len)
+ if (!__xdr_inline_decode(xdr, subbuf->head[0].iov_len))
+ return false;
+
+ remaining = subbuf->page_len;
+ offset = subbuf->page_base;
+ while (remaining) {
+ len = min_t(unsigned int, remaining, PAGE_SIZE) - offset;
+
+ if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
+ return false;
+ if (!__xdr_inline_decode(xdr, len))
+ return false;
+
+ remaining -= len;
+ offset = 0;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(xdr_stream_subsegment);
+
+/**
* 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