Skip to content

Commit

Permalink
libceph: abstract message data
Browse files Browse the repository at this point in the history 
Group the types of message data into an abstract structure with a
type indicator and a union containing fields appropriate to the
type of data it represents.  Use this to represent the pages,
pagelist, bio, and trail in a ceph message.

Verify message data is of type NONE in ceph_msg_data_set_*()
routines.  Since information about message data of type NONE really
should not be interpreted, get rid of the other assertions in those
functions.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
  • Loading branch information
Alex Elder authored and Sage Weil committed May 2, 2013
1 parent f9e1577 commit 4379450
Show file tree
Hide file tree
Showing 2 changed files with 74 additions and 30 deletions.
71 changes: 51 additions & 20 deletions include/linux/ceph/messenger.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -64,12 +64,55 @@ struct ceph_messenger {
u32 required_features;
};

#define ceph_msg_has_pages(m) ((m)->p.pages != NULL)
#define ceph_msg_has_pagelist(m) ((m)->l.pagelist != NULL)
#define ceph_msg_has_pages(m) ((m)->p.type == CEPH_MSG_DATA_PAGES)
#define ceph_msg_has_pagelist(m) ((m)->l.type == CEPH_MSG_DATA_PAGELIST)
#ifdef CONFIG_BLOCK
#define ceph_msg_has_bio(m) ((m)->b.bio != NULL)
#define ceph_msg_has_bio(m) ((m)->b.type == CEPH_MSG_DATA_BIO)
#endif /* CONFIG_BLOCK */
#define ceph_msg_has_trail(m) ((m)->t.trail != NULL)
#define ceph_msg_has_trail(m) ((m)->t.type == CEPH_MSG_DATA_PAGELIST)

enum ceph_msg_data_type {
CEPH_MSG_DATA_NONE, /* message contains no data payload */
CEPH_MSG_DATA_PAGES, /* data source/destination is a page array */
CEPH_MSG_DATA_PAGELIST, /* data source/destination is a pagelist */
#ifdef CONFIG_BLOCK
CEPH_MSG_DATA_BIO, /* data source/destination is a bio list */
#endif /* CONFIG_BLOCK */
};

static __inline__ bool ceph_msg_data_type_valid(enum ceph_msg_data_type type)
{
switch (type) {
case CEPH_MSG_DATA_NONE:
case CEPH_MSG_DATA_PAGES:
case CEPH_MSG_DATA_PAGELIST:
#ifdef CONFIG_BLOCK
case CEPH_MSG_DATA_BIO:
#endif /* CONFIG_BLOCK */
return true;
default:
return false;
}
}

struct ceph_msg_data {
enum ceph_msg_data_type type;
union {
#ifdef CONFIG_BLOCK
struct {
struct bio *bio_iter; /* iterator */
struct bio *bio;
unsigned int bio_seg; /* current seg in bio */
};
#endif /* CONFIG_BLOCK */
struct {
struct page **pages; /* NOT OWNER. */
size_t length; /* total # bytes */
unsigned int alignment; /* first page */
};
struct ceph_pagelist *pagelist;
};
};

/*
* a single message. it contains a header (src, dest, message type, etc.),
Expand All @@ -83,24 +126,12 @@ struct ceph_msg {
struct ceph_buffer *middle;

/* data payload */
struct {
struct page **pages; /* NOT OWNER. */
size_t length; /* # data bytes in array */
unsigned int alignment; /* first page */
} p;
struct {
struct ceph_pagelist *pagelist;
} l;
struct ceph_msg_data p; /* pages */
struct ceph_msg_data l; /* pagelist */
#ifdef CONFIG_BLOCK
struct {
struct bio *bio_iter; /* iterator */
struct bio *bio;
unsigned int bio_seg; /* current seg in bio */
} b;
struct ceph_msg_data b; /* bio */
#endif /* CONFIG_BLOCK */
struct {
struct ceph_pagelist *trail; /* trailing part of data */
} t;
struct ceph_msg_data t; /* trail */

struct ceph_connection *con;
struct list_head list_head; /* links for connection lists */
Expand Down
33 changes: 23 additions & 10 deletions net/ceph/messenger.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1054,7 +1054,7 @@ static void out_msg_pos_next(struct ceph_connection *con, struct page *page,
msg_pos->did_page_crc = false;
if (in_trail) {
BUG_ON(!ceph_msg_has_trail(msg));
list_rotate_left(&msg->t.trail->head);
list_rotate_left(&msg->t.pagelist->head);
} else if (ceph_msg_has_pagelist(msg)) {
list_rotate_left(&msg->l.pagelist->head);
#ifdef CONFIG_BLOCK
Expand Down Expand Up @@ -1120,7 +1120,7 @@ static int write_partial_message_data(struct ceph_connection *con)
size_t trail_off = data_len;

if (ceph_msg_has_trail(msg)) {
trail_len = msg->t.trail->length;
trail_len = msg->t.pagelist->length;
trail_off -= trail_len;
}

Expand Down Expand Up @@ -1149,7 +1149,7 @@ static int write_partial_message_data(struct ceph_connection *con)
if (in_trail) {
BUG_ON(!ceph_msg_has_trail(msg));
total_max_write = data_len - msg_pos->data_pos;
page = list_first_entry(&msg->t.trail->head,
page = list_first_entry(&msg->t.pagelist->head,
struct page, lru);
} else if (ceph_msg_has_pages(msg)) {
page = msg->p.pages[msg_pos->page];
Expand Down Expand Up @@ -2736,14 +2736,19 @@ void ceph_con_keepalive(struct ceph_connection *con)
}
EXPORT_SYMBOL(ceph_con_keepalive);

static void ceph_msg_data_init(struct ceph_msg_data *data)
{
data->type = CEPH_MSG_DATA_NONE;
}

void ceph_msg_data_set_pages(struct ceph_msg *msg, struct page **pages,
size_t length, size_t alignment)
{
BUG_ON(!pages);
BUG_ON(!length);
BUG_ON(msg->p.pages);
BUG_ON(msg->p.length);
BUG_ON(msg->p.type != CEPH_MSG_DATA_NONE);

msg->p.type = CEPH_MSG_DATA_PAGES;
msg->p.pages = pages;
msg->p.length = length;
msg->p.alignment = alignment & ~PAGE_MASK;
Expand All @@ -2755,17 +2760,19 @@ void ceph_msg_data_set_pagelist(struct ceph_msg *msg,
{
BUG_ON(!pagelist);
BUG_ON(!pagelist->length);
BUG_ON(msg->l.pagelist);
BUG_ON(msg->l.type != CEPH_MSG_DATA_NONE);

msg->l.type = CEPH_MSG_DATA_PAGELIST;
msg->l.pagelist = pagelist;
}
EXPORT_SYMBOL(ceph_msg_data_set_pagelist);

void ceph_msg_data_set_bio(struct ceph_msg *msg, struct bio *bio)
{
BUG_ON(!bio);
BUG_ON(msg->b.bio);
BUG_ON(msg->b.type != CEPH_MSG_DATA_NONE);

msg->b.type = CEPH_MSG_DATA_BIO;
msg->b.bio = bio;
}
EXPORT_SYMBOL(ceph_msg_data_set_bio);
Expand All @@ -2774,9 +2781,10 @@ void ceph_msg_data_set_trail(struct ceph_msg *msg, struct ceph_pagelist *trail)
{
BUG_ON(!trail);
BUG_ON(!trail->length);
BUG_ON(msg->t.trail);
BUG_ON(msg->b.type != CEPH_MSG_DATA_NONE);

msg->t.trail = trail;
msg->t.type = CEPH_MSG_DATA_PAGELIST;
msg->t.pagelist = trail;
}
EXPORT_SYMBOL(ceph_msg_data_set_trail);

Expand All @@ -2800,6 +2808,11 @@ struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
INIT_LIST_HEAD(&m->list_head);
kref_init(&m->kref);

ceph_msg_data_init(&m->p);
ceph_msg_data_init(&m->l);
ceph_msg_data_init(&m->b);
ceph_msg_data_init(&m->t);

/* front */
m->front_max = front_len;
if (front_len) {
Expand Down Expand Up @@ -2965,7 +2978,7 @@ void ceph_msg_last_put(struct kref *kref)
}

if (ceph_msg_has_trail(m))
m->t.trail = NULL;
m->t.pagelist = NULL;

if (m->pool)
ceph_msgpool_put(m->pool, m);
Expand Down

0 comments on commit 4379450

Please sign in to comment.