[RFC PATCH 5/5] ceph: switch to netfs_direct_read_iter

[Jeff Layton <jlayton@kernel.org>]

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/ceph/addr.c | 41 +++++++++++++++++++++++++++++------------
 fs/ceph/file.c |  3 +--
 2 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 0726494a0981..bc575bbbf8b7 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -201,7 +201,6 @@ static void finish_netfs_read(struct ceph_osd_request *req)
 	struct ceph_fs_client *fsc = ceph_inode_to_client(req->r_inode);
 	struct ceph_osd_data *osd_data = osd_req_op_extent_osd_data(req, 0);
 	struct netfs_io_subrequest *subreq = req->r_priv;
-	int num_pages;
 	int err = req->r_result;
 
 	ceph_update_read_metrics(&fsc->mdsc->metric, req->r_start_latency,
@@ -216,13 +215,18 @@ static void finish_netfs_read(struct ceph_osd_request *req)
 	else if (err == -EBLOCKLISTED)
 		fsc->blocklisted = true;
 
-	if (err >= 0 && err < subreq->len)
-		__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+	if (err >= 0) {
+		if (err < subreq->len)
+			__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+		iov_iter_advance(&subreq->iter, err);
+	}
+	if (!iov_iter_is_bvec(&subreq->iter))
+		ceph_put_page_vector(osd_data->pages,
+				     calc_pages_for(osd_data->alignment,
+				     osd_data->length),
+				     false);
 
 	netfs_subreq_terminated(subreq, err, true);
-
-	num_pages = calc_pages_for(osd_data->alignment, osd_data->length);
-	ceph_put_page_vector(osd_data->pages, num_pages, false);
 	iput(req->r_inode);
 }
 
@@ -285,6 +289,7 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq)
 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 	struct ceph_osd_request *req;
 	struct ceph_vino vino = ceph_vino(inode);
+	struct iov_iter *iter = &subreq->iter;
 	struct page **pages;
 	size_t page_off;
 	int err = 0;
@@ -308,16 +313,28 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq)
 		__func__, subreq->start, subreq->len, len, rreq->debug_id,
 		subreq->debug_index, iov_iter_count(&subreq->iter));
 
-	err = iov_iter_get_pages_alloc(&subreq->iter, &pages, len, &page_off);
-	if (err < 0) {
-		dout("%s: iov_ter_get_pages_alloc returned %d\n", __func__, err);
-		goto out;
+	if (iov_iter_is_bvec(iter)) {
+		/*
+		 * FIXME: remove force cast, ideally by plumbing an IOV_ITER osd_data
+		 * 	  variant.
+		 */
+		osd_req_op_extent_osd_data_bvecs(req, 0, (__force struct bio_vec *)iter->bvec,
+				iter->nr_segs, len);
+		goto submit;
 	}
 
-	/* FIXME: adjust the len in req downward if necessary */
-	len = err;
+	err = iov_iter_get_pages_alloc(&subreq->iter, &pages, len, &page_off);
+	if (err < len) {
+		if (err < 0) {
+			dout("%s: iov_ter_get_pages_alloc returned %d\n", __func__, err);
+			goto out;
+		}
+		len = err;
+		req->r_ops[0].extent.length = err;
+	}
 
 	osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
+submit:
 	req->r_callback = finish_netfs_read;
 	req->r_priv = subreq;
 	req->r_inode = inode;
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 6c9e837aa1d3..8271459b36dc 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1624,8 +1624,7 @@ static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to)
 
 		if (ci->i_inline_version == CEPH_INLINE_NONE) {
 			if (!retry_op && (iocb->ki_flags & IOCB_DIRECT)) {
-				ret = ceph_direct_read_write(iocb, to,
-							     NULL, NULL);
+				ret = netfs_direct_read_iter(iocb, to);
 				if (ret >= 0 && ret < len)
 					retry_op = CHECK_EOF;
 			} else {
-- 
2.35.1