diff options
| -rw-r--r-- | include/linux/ceph/messenger.h | 8 | ||||
| -rw-r--r-- | net/ceph/messenger.c | 117 |
2 files changed, 99 insertions, 26 deletions
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h index 14862438faff..716c3fdeb257 100644 --- a/include/linux/ceph/messenger.h +++ b/include/linux/ceph/messenger.h @@ -97,8 +97,12 @@ static __inline__ bool ceph_msg_data_type_valid(enum ceph_msg_data_type type) struct ceph_msg_data_cursor { bool last_piece; /* now at last piece of data item */ - struct page *page; /* current page in pagelist */ - size_t offset; /* pagelist bytes consumed */ + union { + struct { /* pagelist */ + struct page *page; /* page from list */ + size_t offset; /* bytes from list */ + }; + }; }; struct ceph_msg_data { diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index b978cf8b27ff..4cc27a136e35 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -742,21 +742,16 @@ static void iter_bio_next(struct bio **bio_iter, unsigned int *seg) #endif /* - * Message data is handled (sent or received) in pieces, where each - * piece resides on a single page. The network layer might not - * consume an entire piece at once. A data item's cursor keeps - * track of which piece is next to process and how much remains to - * be processed in that piece. It also tracks whether the current - * piece is the last one in the data item. + * For a pagelist, a piece is whatever remains to be consumed in the + * first page in the list, or the front of the next page. */ -static void ceph_msg_data_cursor_init(struct ceph_msg_data *data) +static void ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data *data) { struct ceph_msg_data_cursor *cursor = &data->cursor; struct ceph_pagelist *pagelist; struct page *page; - if (data->type != CEPH_MSG_DATA_PAGELIST) - return; + BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST); pagelist = data->pagelist; BUG_ON(!pagelist); @@ -771,15 +766,9 @@ static void ceph_msg_data_cursor_init(struct ceph_msg_data *data) cursor->last_piece = pagelist->length <= PAGE_SIZE; } -/* - * Return the page containing the next piece to process for a given - * data item, and supply the page offset and length of that piece. - * Indicate whether this is the last piece in this data item. - */ -static struct page *ceph_msg_data_next(struct ceph_msg_data *data, +static struct page *ceph_msg_data_pagelist_next(struct ceph_msg_data *data, size_t *page_offset, - size_t *length, - bool *last_piece) + size_t *length) { struct ceph_msg_data_cursor *cursor = &data->cursor; struct ceph_pagelist *pagelist; @@ -793,8 +782,7 @@ static struct page *ceph_msg_data_next(struct ceph_msg_data *data, BUG_ON(!cursor->page); BUG_ON(cursor->offset >= pagelist->length); - *last_piece = cursor->last_piece; - if (*last_piece) { + if (cursor->last_piece) { /* pagelist offset is always 0 */ piece_end = pagelist->length & ~PAGE_MASK; if (!piece_end) @@ -808,11 +796,8 @@ static struct page *ceph_msg_data_next(struct ceph_msg_data *data, return data->cursor.page; } -/* - * Returns true if the result moves the cursor on to the next piece - * (the next page) of the pagelist. - */ -static bool ceph_msg_data_advance(struct ceph_msg_data *data, size_t bytes) +static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data *data, + size_t bytes) { struct ceph_msg_data_cursor *cursor = &data->cursor; struct ceph_pagelist *pagelist; @@ -844,6 +829,90 @@ static bool ceph_msg_data_advance(struct ceph_msg_data *data, size_t bytes) return true; } +/* + * Message data is handled (sent or received) in pieces, where each + * piece resides on a single page. The network layer might not + * consume an entire piece at once. A data item's cursor keeps + * track of which piece is next to process and how much remains to + * be processed in that piece. It also tracks whether the current + * piece is the last one in the data item. + */ +static void ceph_msg_data_cursor_init(struct ceph_msg_data *data) +{ + switch (data->type) { + case CEPH_MSG_DATA_PAGELIST: + ceph_msg_data_pagelist_cursor_init(data); + break; + case CEPH_MSG_DATA_NONE: + case CEPH_MSG_DATA_PAGES: +#ifdef CONFIG_BLOCK + case CEPH_MSG_DATA_BIO: +#endif /* CONFIG_BLOCK */ + default: + /* BUG(); */ + break; + } +} + +/* + * Return the page containing the next piece to process for a given + * data item, and supply the page offset and length of that piece. + * Indicate whether this is the last piece in this data item. + */ +static struct page *ceph_msg_data_next(struct ceph_msg_data *data, + size_t *page_offset, + size_t *length, + bool *last_piece) +{ + struct page *page; + + switch (data->type) { + case CEPH_MSG_DATA_PAGELIST: + page = ceph_msg_data_pagelist_next(data, page_offset, length); + break; + case CEPH_MSG_DATA_NONE: + case CEPH_MSG_DATA_PAGES: +#ifdef CONFIG_BLOCK + case CEPH_MSG_DATA_BIO: +#endif /* CONFIG_BLOCK */ + default: + page = NULL; + break; + } + BUG_ON(!page); + BUG_ON(*page_offset + *length > PAGE_SIZE); + BUG_ON(!*length); + if (last_piece) + *last_piece = data->cursor.last_piece; + + return page; +} + +/* + * Returns true if the result moves the cursor on to the next piece + * of the data item. + */ +static bool ceph_msg_data_advance(struct ceph_msg_data *data, size_t bytes) +{ + bool new_piece; + + switch (data->type) { + case CEPH_MSG_DATA_PAGELIST: + new_piece = ceph_msg_data_pagelist_advance(data, bytes); + break; + case CEPH_MSG_DATA_NONE: + case CEPH_MSG_DATA_PAGES: +#ifdef CONFIG_BLOCK + case CEPH_MSG_DATA_BIO: +#endif /* CONFIG_BLOCK */ + default: + BUG(); + break; + } + + return new_piece; +} + static void prepare_message_data(struct ceph_msg *msg, struct ceph_msg_pos *msg_pos) { |