libceph: move cursor into message
A message will only be processing a single data item at a time, so
there's no need for each data item to have its own cursor.
Move the cursor embedded in the message data structure into the
message itself. To minimize the impact, keep the data->cursor
field, but make it be a pointer to the cursor in the message.
Move the definition of ceph_msg_data above ceph_msg_data_cursor so
the cursor can point to the data without a forward definition rather
than vice-versa.
This and the upcoming patches are part of:
http://tracker.ceph.com/issues/3761
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index 4fb870a..e755724 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -88,6 +88,25 @@
}
}
+struct ceph_msg_data {
+ enum ceph_msg_data_type type;
+ union {
+#ifdef CONFIG_BLOCK
+ struct {
+ struct bio *bio;
+ size_t bio_length;
+ };
+#endif /* CONFIG_BLOCK */
+ struct {
+ struct page **pages; /* NOT OWNER. */
+ size_t length; /* total # bytes */
+ unsigned int alignment; /* first page */
+ };
+ struct ceph_pagelist *pagelist;
+ };
+ struct ceph_msg_data_cursor *cursor;
+};
+
struct ceph_msg_data_cursor {
size_t resid; /* bytes not yet consumed */
bool last_piece; /* now at last piece of data item */
@@ -112,25 +131,6 @@
};
};
-struct ceph_msg_data {
- enum ceph_msg_data_type type;
- union {
-#ifdef CONFIG_BLOCK
- struct {
- struct bio *bio;
- size_t bio_length;
- };
-#endif /* CONFIG_BLOCK */
- struct {
- struct page **pages; /* NOT OWNER. */
- size_t length; /* total # bytes */
- unsigned int alignment; /* first page */
- };
- struct ceph_pagelist *pagelist;
- };
- struct ceph_msg_data_cursor cursor; /* pagelist only */
-};
-
/*
* a single message. it contains a header (src, dest, message type, etc.),
* footer (crc values, mainly), a "front" message body, and possibly a
@@ -142,8 +142,9 @@
struct kvec front; /* unaligned blobs of message */
struct ceph_buffer *middle;
- size_t data_length;
- struct ceph_msg_data *data; /* data payload */
+ size_t data_length;
+ struct ceph_msg_data *data;
+ struct ceph_msg_data_cursor cursor;
struct ceph_connection *con;
struct list_head list_head; /* links for connection lists */