[RFC PATCH 17/18] ceph: Remove CEPH_MSG_DATA_PAGES and its helpers

[David Howells]

---
 include/linux/ceph/messenger.h | 26 ++-------
 net/ceph/messenger.c           | 98 +---------------------------------
 net/ceph/osd_client.c          |  2 -
 3 files changed, 5 insertions(+), 121 deletions(-)

diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index a2489e266bff..f48657eef648 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -118,23 +118,14 @@ struct ceph_messenger {
 enum ceph_msg_data_type {
 	CEPH_MSG_DATA_NONE,	/* message contains no data payload */
 	CEPH_MSG_DATA_DATABUF,	/* data source/destination is a data buffer */
-	CEPH_MSG_DATA_PAGES,	/* data source/destination is a page array */
 	CEPH_MSG_DATA_ITER,	/* data source/destination is an iov_iter */
 };
 
 struct ceph_msg_data {
 	enum ceph_msg_data_type		type;
-	struct iov_iter			iter;
 	bool				release_dbuf;
-	union {
-		struct ceph_databuf	*dbuf;
-		struct {
-			struct page	**pages;
-			size_t		length;		/* total # bytes */
-			unsigned int	offset;		/* first page */
-			bool		own_pages;
-		};
-	};
+	struct iov_iter			iter;
+	struct ceph_databuf		*dbuf;
 };
 
 struct ceph_msg_data_cursor {
@@ -144,17 +135,8 @@ struct ceph_msg_data_cursor {
 	size_t			resid;		/* bytes not yet consumed */
 	int			sr_resid;	/* residual sparse_read len */
 	bool			need_crc;	/* crc update needed */
-	union {
-		struct {				/* pages */
-			unsigned int	page_offset;	/* offset in page */
-			unsigned short	page_index;	/* index in array */
-			unsigned short	page_count;	/* pages in array */
-		};
-		struct {
-			struct iov_iter		iov_iter;
-			unsigned int		lastlen;
-		};
-	};
+	struct iov_iter		iov_iter;
+	unsigned int		lastlen;
 };
 
 /*
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 5b28c27858b2..acbdd086cd7a 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -710,70 +710,6 @@ void ceph_con_discard_requeued(struct ceph_connection *con, u64 reconnect_seq)
 	}
 }
 
-/*
- * For a page array, a piece comes from the first page in the array
- * that has not already been fully consumed.
- */
-static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data_cursor *cursor,
-					size_t length)
-{
-	struct ceph_msg_data *data = cursor->data;
-	int page_count;
-
-	BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
-
-	BUG_ON(!data->pages);
-	BUG_ON(!data->length);
-
-	cursor->resid = min(length, data->length);
-	page_count = calc_pages_for(data->offset, (u64)data->length);
-	cursor->page_offset = data->offset & ~PAGE_MASK;
-	cursor->page_index = 0;
-	BUG_ON(page_count > (int)USHRT_MAX);
-	cursor->page_count = (unsigned short)page_count;
-	BUG_ON(length > SIZE_MAX - cursor->page_offset);
-}
-
-static struct page *
-ceph_msg_data_pages_next(struct ceph_msg_data_cursor *cursor,
-					size_t *page_offset, size_t *length)
-{
-	struct ceph_msg_data *data = cursor->data;
-
-	BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
-
-	BUG_ON(cursor->page_index >= cursor->page_count);
-	BUG_ON(cursor->page_offset >= PAGE_SIZE);
-
-	*page_offset = cursor->page_offset;
-	*length = min_t(size_t, cursor->resid, PAGE_SIZE - *page_offset);
-	return data->pages[cursor->page_index];
-}
-
-static bool ceph_msg_data_pages_advance(struct ceph_msg_data_cursor *cursor,
-						size_t bytes)
-{
-	BUG_ON(cursor->data->type != CEPH_MSG_DATA_PAGES);
-
-	BUG_ON(cursor->page_offset + bytes > PAGE_SIZE);
-
-	/* Advance the cursor page offset */
-
-	cursor->resid -= bytes;
-	cursor->page_offset = (cursor->page_offset + bytes) & ~PAGE_MASK;
-	if (!bytes || cursor->page_offset)
-		return false;	/* more bytes to process in the current page */
-
-	if (!cursor->resid)
-		return false;   /* no more data */
-
-	/* Move on to the next page; offset is already at 0 */
-
-	BUG_ON(cursor->page_index >= cursor->page_count);
-	cursor->page_index++;
-	return true;
-}
-
 static void ceph_msg_data_iter_cursor_init(struct ceph_msg_data_cursor *cursor,
 					size_t length)
 {
@@ -844,9 +780,6 @@ static void __ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor)
 	size_t length = cursor->total_resid;
 
 	switch (cursor->data->type) {
-	case CEPH_MSG_DATA_PAGES:
-		ceph_msg_data_pages_cursor_init(cursor, length);
-		break;
 	case CEPH_MSG_DATA_ITER:
 		ceph_msg_data_iter_cursor_init(cursor, length);
 		break;
@@ -883,9 +816,6 @@ struct page *ceph_msg_data_next(struct ceph_msg_data_cursor *cursor,
 	struct page *page;
 
 	switch (cursor->data->type) {
-	case CEPH_MSG_DATA_PAGES:
-		page = ceph_msg_data_pages_next(cursor, page_offset, length);
-		break;
 	case CEPH_MSG_DATA_ITER:
 		page = ceph_msg_data_iter_next(cursor, page_offset, length);
 		break;
@@ -913,9 +843,6 @@ void ceph_msg_data_advance(struct ceph_msg_data_cursor *cursor, size_t bytes)
 
 	BUG_ON(bytes > cursor->resid);
 	switch (cursor->data->type) {
-	case CEPH_MSG_DATA_PAGES:
-		new_piece = ceph_msg_data_pages_advance(cursor, bytes);
-		break;
 	case CEPH_MSG_DATA_ITER:
 		new_piece = ceph_msg_data_iter_advance(cursor, bytes);
 		break;
@@ -1644,12 +1571,8 @@ static struct ceph_msg_data *ceph_msg_data_add(struct ceph_msg *msg)
 
 static void ceph_msg_data_destroy(struct ceph_msg_data *data)
 {
-	if (data->release_dbuf) {
+	if (data->release_dbuf)
 		ceph_databuf_release(data->dbuf);
-	} else if (data->type == CEPH_MSG_DATA_PAGES && data->own_pages) {
-		int num_pages = calc_pages_for(data->offset, data->length);
-		ceph_release_page_vector(data->pages, num_pages);
-	}
 }
 
 void ceph_msg_data_add_databuf(struct ceph_msg *msg, struct ceph_databuf *dbuf)
@@ -1670,25 +1593,6 @@ void ceph_msg_data_add_databuf(struct ceph_msg *msg, struct ceph_databuf *dbuf)
 }
 EXPORT_SYMBOL(ceph_msg_data_add_databuf);
 
-void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
-			     size_t length, size_t offset, bool own_pages)
-{
-	struct ceph_msg_data *data;
-
-	BUG_ON(!pages);
-	BUG_ON(!length);
-
-	data = ceph_msg_data_add(msg);
-	data->type = CEPH_MSG_DATA_PAGES;
-	data->pages = pages;
-	data->length = length;
-	data->offset = offset & ~PAGE_MASK;
-	data->own_pages = own_pages;
-
-	msg->data_length += length;
-}
-EXPORT_SYMBOL(ceph_msg_data_add_pages);
-
 void ceph_msg_data_add_iter(struct ceph_msg *msg,
 			    struct iov_iter *iter)
 {
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 70f81a0b62c0..6fb78ae14f03 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -829,8 +829,6 @@ EXPORT_SYMBOL(osd_req_op_alloc_hint_init);
 static void ceph_osdc_msg_data_add(struct ceph_msg *msg,
 				struct ceph_osd_data *osd_data)
 {
-	u64 length = ceph_osd_data_length(osd_data);
-
 	if (osd_data->type == CEPH_OSD_DATA_TYPE_ITER) {
 		ceph_msg_data_add_iter(msg, &osd_data->iter);
 	} else {