libceph: isolate message page field manipulation

Define a function ceph_msg_data_set_pages(), which more clearly
abstracts the assignment page-related fields for data in a ceph
message structure.  Use this new function in the osd client and mds
client.

Ideally, these fields would never be set more than once (with
BUG_ON() calls to guarantee that).  At the moment though the osd
client sets these every time it receives a message, and in the event
of a communication problem this can happen more than once.  (This
will be resolved shortly, but setting up these helpers first makes
it all a bit easier to work with.)

Rearrange the field order in a ceph_msg structure to group those
that are used to define the possible data payloads.

This partially resolves:
    http://tracker.ceph.com/issues/4263

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit is contained in:
Alex Elder
2013-02-14 12:16:43 -06:00
committed by Sage Weil
parent e0c594878e
commit 02afca6ca0
4 changed files with 30 additions and 17 deletions

View File

@@ -74,21 +74,22 @@ struct ceph_msg {
struct ceph_msg_footer footer; /* footer */
struct kvec front; /* unaligned blobs of message */
struct ceph_buffer *middle;
struct page **pages; /* data payload. NOT OWNER. */
unsigned page_count; /* size of page array */
unsigned page_alignment; /* io offset in first page */
struct page **pages; /* data payload. NOT OWNER. */
unsigned int page_alignment; /* io offset in first page */
unsigned int page_count; /* # pages in array or list */
struct ceph_pagelist *pagelist; /* instead of pages */
struct ceph_connection *con;
struct list_head list_head;
struct kref kref;
#ifdef CONFIG_BLOCK
unsigned int bio_seg; /* current bio segment */
struct bio *bio; /* instead of pages/pagelist */
struct bio *bio_iter; /* bio iterator */
unsigned int bio_seg; /* current bio segment */
#endif /* CONFIG_BLOCK */
struct ceph_pagelist *trail; /* the trailing part of the data */
struct ceph_connection *con;
struct list_head list_head; /* links for connection lists */
struct kref kref;
bool front_is_vmalloc;
bool more_to_follow;
bool needs_out_seq;
@@ -218,6 +219,9 @@ extern void ceph_msg_revoke_incoming(struct ceph_msg *msg);
extern void ceph_con_keepalive(struct ceph_connection *con);
extern void ceph_msg_data_set_pages(struct ceph_msg *msg, struct page **pages,
unsigned int page_count, size_t alignment);
extern struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
bool can_fail);
extern void ceph_msg_kfree(struct ceph_msg *m);