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Commit 43794509 authored by Alex Elder's avatar Alex Elder Committed by Sage Weil
Browse files

libceph: abstract message data 



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: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent f9e15777

include/linux/ceph/messenger.h

+51 −20
Original line number Diff line number Diff line
@@ -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.),
@@ -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 */

net/ceph/messenger.c

+23 −10
Original line number Diff line number Diff line
@@ -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
@@ -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;

	}
@@ -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];
@@ -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;
@@ -2755,8 +2760,9 @@ 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);
@@ -2764,8 +2770,9 @@ 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);
@@ -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);
@@ -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) {
@@ -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);