From 437945094fed0deb1810e8da95465c8f26bc6f80 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Fri, 1 Mar 2013 18:00:16 -0600 Subject: [PATCH] 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: Alex Elder Reviewed-by: Josh Durgin --- include/linux/ceph/messenger.h | 71 ++++++++++++++++++++++++++++++------------ net/ceph/messenger.c | 33 ++++++++++++++------ 2 files changed, 74 insertions(+), 30 deletions(-) diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h index fb2b18a..5860dd0 100644 --- a/include/linux/ceph/messenger.h +++ b/include/linux/ceph/messenger.h @@ -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 */ diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index f485455..f256b4b 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -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); -- 2.7.4