[RFC PATCH 3/5] ceph: Use the provided iterator in ceph_netfs_issue_op()

[Jeff Layton <jlayton@kernel.org>]

From: David Howells <dhowells@redhat.com>

The netfs_read_subrequest struct now contains a persistent iterator
representing the destination buffer for a read that the network filesystem
should use.  Make ceph use this.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/ceph/addr.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index f0af362f8756..e7a7b5d29c7d 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -233,7 +233,6 @@ static bool ceph_netfs_issue_op_inline(struct netfs_io_subrequest *subreq)
 	struct ceph_mds_request *req;
 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(inode->i_sb);
 	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct iov_iter iter;
 	ssize_t err = 0;
 	size_t len;
 
@@ -266,8 +265,7 @@ static bool ceph_netfs_issue_op_inline(struct netfs_io_subrequest *subreq)
 	}
 
 	len = min_t(size_t, iinfo->inline_len - subreq->start, subreq->len);
-	iov_iter_xarray(&iter, READ, &rreq->mapping->i_pages, subreq->start, len);
-	err = copy_to_iter(iinfo->inline_data + subreq->start, len, &iter);
+	err = copy_to_iter(iinfo->inline_data + subreq->start, len, &subreq->iter);
 	if (err == 0)
 		err = -EFAULT;
 
@@ -285,7 +283,6 @@ 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;
 	struct page **pages;
 	size_t page_off;
 	int err = 0;
@@ -306,15 +303,14 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq)
 	}
 
 	dout("%s: pos=%llu orig_len=%zu len=%llu\n", __func__, subreq->start, subreq->len, len);
-	iov_iter_xarray(&iter, READ, &rreq->mapping->i_pages, subreq->start, len);
-	err = iov_iter_get_pages_alloc(&iter, &pages, len, &page_off);
+
+	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;
 	}
 
-	/* should always give us a page-aligned read */
-	WARN_ON_ONCE(page_off);
+	/* FIXME: adjust the len in req downward if necessary */
 	len = err;
 
 	osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
-- 
2.35.1