From: Chuck Lever <chuck.lever@xxxxxxxxxx>
Now that the preparation of an rq_vec has been removed from the
generic read path, nfsd_splice_read() no longer needs to reset
rq_next_page.
nfsd4_encode_read() calls nfsd_splice_read() directly. As far as I
can ascertain, resetting rq_next_page for NFSv4 splice reads is
unnecessary because rq_next_page is already set correctly.
Moreover, resetting it might even be incorrect if previous
operations in the COMPOUND have already consumed at least a page of
the send buffer. I would expect that the result would be encoding
the READ payload over previously-encoded results.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfsd/nfs4xdr.c | 10 +++++-----
fs/nfsd/vfs.c | 13 ++++++++++++-
include/linux/sunrpc/xdr.h | 3 +--
net/sunrpc/xdr.c | 26 ++++++++++++--------------
4 files changed, 30 insertions(+), 22 deletions(-)
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 23dd09c4b2cd..b83954fc57e3 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4104,13 +4104,13 @@ static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
__be32 zero = xdr_zero;
__be32 nfserr;
- read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, maxcount);
- if (read->rd_vlen < 0)
+ if (xdr_reserve_space_vec(xdr, maxcount) < 0)
return nfserr_resource;
- nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
- resp->rqstp->rq_vec, read->rd_vlen, &maxcount,
- &read->rd_eof);
+ nfserr = nfsd_iter_read(resp->rqstp, read->rd_fhp, file,
+ read->rd_offset, &maxcount,
+ xdr->buf->page_len & ~PAGE_MASK,
+ &read->rd_eof);
read->rd_length = maxcount;
if (nfserr)
return nfserr;
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 054d58d01299..13ccd385b308 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -995,6 +995,18 @@ static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
}
}
+/**
+ * nfsd_splice_read - Perform a VFS read using a splice pipe
+ * @rqstp: RPC transaction context
+ * @fhp: file handle of file to be read
+ * @file: opened struct file of file to be read
+ * @offset: starting byte offset
+ * @count: IN: requested number of bytes; OUT: number of bytes read
+ * @eof: OUT: set non-zero if operation reached the end of the file
+ *
+ * Returns nfs_ok on success, otherwise an nfserr stat value is
+ * returned.
+ */
__be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
struct file *file, loff_t offset, unsigned long *count,
u32 *eof)
@@ -1008,7 +1020,6 @@ __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
ssize_t host_err;
trace_nfsd_read_splice(rqstp, fhp, offset, *count);
- rqstp->rq_next_page = rqstp->rq_respages + 1;
host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
}
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 72014c9216fc..f89ec4b5ea16 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -242,8 +242,7 @@ extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
extern void xdr_init_encode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
struct page **pages, struct rpc_rqst *rqst);
extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
-extern int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec,
- size_t nbytes);
+extern int xdr_reserve_space_vec(struct xdr_stream *xdr, size_t nbytes);
extern void __xdr_commit_encode(struct xdr_stream *xdr);
extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
extern void xdr_truncate_decode(struct xdr_stream *xdr, size_t len);
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 36835b2f5446..2a22e78af116 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -1070,22 +1070,22 @@ __be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes)
}
EXPORT_SYMBOL_GPL(xdr_reserve_space);
-
/**
* xdr_reserve_space_vec - Reserves a large amount of buffer space for sending
* @xdr: pointer to xdr_stream
- * @vec: pointer to a kvec array
* @nbytes: number of bytes to reserve
*
- * Reserves enough buffer space to encode 'nbytes' of data and stores the
- * pointers in 'vec'. The size argument passed to xdr_reserve_space() is
- * determined based on the number of bytes remaining in the current page to
- * avoid invalidating iov_base pointers when xdr_commit_encode() is called.
+ * The size argument passed to xdr_reserve_space() is determined based
+ * on the number of bytes remaining in the current page to avoid
+ * invalidating iov_base pointers when xdr_commit_encode() is called.
+ *
+ * Return values:
+ * %0: success
+ * %-EMSGSIZE: not enough space is available in @xdr
*/
-int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec, size_t nbytes)
+int xdr_reserve_space_vec(struct xdr_stream *xdr, size_t nbytes)
{
- int thislen;
- int v = 0;
+ size_t thislen;
__be32 *p;
/*
@@ -1097,21 +1097,19 @@ int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec, size_t nbyte
xdr->end = xdr->p;
}
+ /* XXX: Let's find a way to make this more efficient */
while (nbytes) {
thislen = xdr->buf->page_len % PAGE_SIZE;
thislen = min_t(size_t, nbytes, PAGE_SIZE - thislen);
p = xdr_reserve_space(xdr, thislen);
if (!p)
- return -EIO;
+ return -EMSGSIZE;
- vec[v].iov_base = p;
- vec[v].iov_len = thislen;
- v++;
nbytes -= thislen;
}
- return v;
+ return 0;
}
EXPORT_SYMBOL_GPL(xdr_reserve_space_vec);
