diff options
Diffstat (limited to 'net/ceph/messenger.c')
-rw-r--r-- | net/ceph/messenger.c | 111 |
1 files changed, 62 insertions, 49 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 95f90b01f75..0ac4f6cb733 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -745,7 +745,8 @@ static void iter_bio_next(struct bio **bio_iter, unsigned int *seg) * entry in the current bio iovec, or the first entry in the next * bio in the list. */ -static void ceph_msg_data_bio_cursor_init(struct ceph_msg_data *data) +static void ceph_msg_data_bio_cursor_init(struct ceph_msg_data *data, + size_t length) { struct ceph_msg_data_cursor *cursor = &data->cursor; struct bio *bio; @@ -755,12 +756,12 @@ static void ceph_msg_data_bio_cursor_init(struct ceph_msg_data *data) bio = data->bio; BUG_ON(!bio); BUG_ON(!bio->bi_vcnt); - /* resid = bio->bi_size */ + cursor->resid = length; cursor->bio = bio; cursor->vector_index = 0; cursor->vector_offset = 0; - cursor->last_piece = !bio->bi_next && bio->bi_vcnt == 1; + cursor->last_piece = length <= bio->bi_io_vec[0].bv_len; } static struct page *ceph_msg_data_bio_next(struct ceph_msg_data *data, @@ -784,8 +785,12 @@ static struct page *ceph_msg_data_bio_next(struct ceph_msg_data *data, BUG_ON(cursor->vector_offset >= bio_vec->bv_len); *page_offset = (size_t) (bio_vec->bv_offset + cursor->vector_offset); BUG_ON(*page_offset >= PAGE_SIZE); - *length = (size_t) (bio_vec->bv_len - cursor->vector_offset); + if (cursor->last_piece) /* pagelist offset is always 0 */ + *length = cursor->resid; + else + *length = (size_t) (bio_vec->bv_len - cursor->vector_offset); BUG_ON(*length > PAGE_SIZE); + BUG_ON(*length > cursor->resid); return bio_vec->bv_page; } @@ -805,26 +810,33 @@ static bool ceph_msg_data_bio_advance(struct ceph_msg_data *data, size_t bytes) index = cursor->vector_index; BUG_ON(index >= (unsigned int) bio->bi_vcnt); bio_vec = &bio->bi_io_vec[index]; - BUG_ON(cursor->vector_offset + bytes > bio_vec->bv_len); /* Advance the cursor offset */ + BUG_ON(cursor->resid < bytes); + cursor->resid -= bytes; cursor->vector_offset += bytes; if (cursor->vector_offset < bio_vec->bv_len) return false; /* more bytes to process in this segment */ + BUG_ON(cursor->vector_offset != bio_vec->bv_len); /* Move on to the next segment, and possibly the next bio */ - if (++cursor->vector_index == (unsigned int) bio->bi_vcnt) { + if (++index == (unsigned int) bio->bi_vcnt) { bio = bio->bi_next; - cursor->bio = bio; - cursor->vector_index = 0; + index = 0; } + cursor->bio = bio; + cursor->vector_index = index; cursor->vector_offset = 0; - if (!cursor->last_piece && bio && !bio->bi_next) - if (cursor->vector_index == (unsigned int) bio->bi_vcnt - 1) + if (!cursor->last_piece) { + BUG_ON(!cursor->resid); + BUG_ON(!bio); + /* A short read is OK, so use <= rather than == */ + if (cursor->resid <= bio->bi_io_vec[index].bv_len) cursor->last_piece = true; + } return true; } @@ -834,7 +846,8 @@ static bool ceph_msg_data_bio_advance(struct ceph_msg_data *data, size_t bytes) * For a page array, a piece comes from the first page in the array * that has not already been fully consumed. */ -static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data *data) +static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data *data, + size_t length) { struct ceph_msg_data_cursor *cursor = &data->cursor; int page_count; @@ -843,14 +856,15 @@ static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data *data) BUG_ON(!data->pages); BUG_ON(!data->length); + BUG_ON(length != data->length); + cursor->resid = length; page_count = calc_pages_for(data->alignment, (u64)data->length); - BUG_ON(page_count > (int) USHRT_MAX); - cursor->resid = data->length; cursor->page_offset = data->alignment & ~PAGE_MASK; cursor->page_index = 0; + BUG_ON(page_count > (int) USHRT_MAX); cursor->page_count = (unsigned short) page_count; - cursor->last_piece = cursor->page_count == 1; + cursor->last_piece = length <= PAGE_SIZE; } static struct page *ceph_msg_data_pages_next(struct ceph_msg_data *data, @@ -863,15 +877,12 @@ static struct page *ceph_msg_data_pages_next(struct ceph_msg_data *data, BUG_ON(cursor->page_index >= cursor->page_count); BUG_ON(cursor->page_offset >= PAGE_SIZE); - BUG_ON(!cursor->resid); *page_offset = cursor->page_offset; - if (cursor->last_piece) { - BUG_ON(*page_offset + cursor->resid > PAGE_SIZE); + if (cursor->last_piece) *length = cursor->resid; - } else { + else *length = PAGE_SIZE - *page_offset; - } return data->pages[cursor->page_index]; } @@ -884,7 +895,6 @@ static bool ceph_msg_data_pages_advance(struct ceph_msg_data *data, BUG_ON(data->type != CEPH_MSG_DATA_PAGES); BUG_ON(cursor->page_offset + bytes > PAGE_SIZE); - BUG_ON(bytes > cursor->resid); /* Advance the cursor page offset */ @@ -898,7 +908,7 @@ static bool ceph_msg_data_pages_advance(struct ceph_msg_data *data, BUG_ON(cursor->page_index >= cursor->page_count); cursor->page_offset = 0; cursor->page_index++; - cursor->last_piece = cursor->page_index == cursor->page_count - 1; + cursor->last_piece = cursor->resid <= PAGE_SIZE; return true; } @@ -907,7 +917,8 @@ static bool ceph_msg_data_pages_advance(struct ceph_msg_data *data, * 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_pagelist_cursor_init(struct ceph_msg_data *data) +static void ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data *data, + size_t length) { struct ceph_msg_data_cursor *cursor = &data->cursor; struct ceph_pagelist *pagelist; @@ -917,15 +928,18 @@ static void ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data *data) pagelist = data->pagelist; BUG_ON(!pagelist); - if (!pagelist->length) + BUG_ON(length != pagelist->length); + + if (!length) return; /* pagelist can be assigned but empty */ BUG_ON(list_empty(&pagelist->head)); page = list_first_entry(&pagelist->head, struct page, lru); + cursor->resid = length; cursor->page = page; cursor->offset = 0; - cursor->last_piece = pagelist->length <= PAGE_SIZE; + cursor->last_piece = length <= PAGE_SIZE; } static struct page *ceph_msg_data_pagelist_next(struct ceph_msg_data *data, @@ -934,7 +948,6 @@ static struct page *ceph_msg_data_pagelist_next(struct ceph_msg_data *data, { struct ceph_msg_data_cursor *cursor = &data->cursor; struct ceph_pagelist *pagelist; - size_t piece_end; BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST); @@ -942,18 +955,13 @@ static struct page *ceph_msg_data_pagelist_next(struct ceph_msg_data *data, BUG_ON(!pagelist); BUG_ON(!cursor->page); - BUG_ON(cursor->offset >= pagelist->length); + BUG_ON(cursor->offset + cursor->resid != pagelist->length); - if (cursor->last_piece) { - /* pagelist offset is always 0 */ - piece_end = pagelist->length & ~PAGE_MASK; - if (!piece_end) - piece_end = PAGE_SIZE; - } else { - piece_end = PAGE_SIZE; - } *page_offset = cursor->offset & ~PAGE_MASK; - *length = piece_end - *page_offset; + if (cursor->last_piece) /* pagelist offset is always 0 */ + *length = cursor->resid; + else + *length = PAGE_SIZE - *page_offset; return data->cursor.page; } @@ -968,12 +976,13 @@ static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data *data, pagelist = data->pagelist; BUG_ON(!pagelist); - BUG_ON(!cursor->page); - BUG_ON(cursor->offset + bytes > pagelist->length); + + BUG_ON(cursor->offset + cursor->resid != pagelist->length); BUG_ON((cursor->offset & ~PAGE_MASK) + bytes > PAGE_SIZE); /* Advance the cursor offset */ + cursor->resid -= bytes; cursor->offset += bytes; /* pagelist offset is always 0 */ if (!bytes || cursor->offset & ~PAGE_MASK) @@ -983,10 +992,7 @@ static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data *data, BUG_ON(list_is_last(&cursor->page->lru, &pagelist->head)); cursor->page = list_entry_next(cursor->page, lru); - - /* cursor offset is at page boundary; pagelist offset is always 0 */ - if (pagelist->length - cursor->offset <= PAGE_SIZE) - cursor->last_piece = true; + cursor->last_piece = cursor->resid <= PAGE_SIZE; return true; } @@ -999,18 +1005,19 @@ static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data *data, * 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) +static void ceph_msg_data_cursor_init(struct ceph_msg_data *data, + size_t length) { switch (data->type) { case CEPH_MSG_DATA_PAGELIST: - ceph_msg_data_pagelist_cursor_init(data); + ceph_msg_data_pagelist_cursor_init(data, length); break; case CEPH_MSG_DATA_PAGES: - ceph_msg_data_pages_cursor_init(data); + ceph_msg_data_pages_cursor_init(data, length); break; #ifdef CONFIG_BLOCK case CEPH_MSG_DATA_BIO: - ceph_msg_data_bio_cursor_init(data); + ceph_msg_data_bio_cursor_init(data, length); break; #endif /* CONFIG_BLOCK */ case CEPH_MSG_DATA_NONE: @@ -1064,8 +1071,10 @@ static struct page *ceph_msg_data_next(struct ceph_msg_data *data, */ static bool ceph_msg_data_advance(struct ceph_msg_data *data, size_t bytes) { + struct ceph_msg_data_cursor *cursor = &data->cursor; bool new_piece; + BUG_ON(bytes > cursor->resid); switch (data->type) { case CEPH_MSG_DATA_PAGELIST: new_piece = ceph_msg_data_pagelist_advance(data, bytes); @@ -1090,8 +1099,12 @@ static bool ceph_msg_data_advance(struct ceph_msg_data *data, size_t bytes) static void prepare_message_data(struct ceph_msg *msg, struct ceph_msg_pos *msg_pos) { + size_t data_len; + BUG_ON(!msg); - BUG_ON(!msg->hdr.data_len); + + data_len = le32_to_cpu(msg->hdr.data_len); + BUG_ON(!data_len); /* initialize page iterator */ msg_pos->page = 0; @@ -1109,12 +1122,12 @@ static void prepare_message_data(struct ceph_msg *msg, #ifdef CONFIG_BLOCK if (ceph_msg_has_bio(msg)) - ceph_msg_data_cursor_init(&msg->b); + ceph_msg_data_cursor_init(&msg->b, data_len); #endif /* CONFIG_BLOCK */ if (ceph_msg_has_pages(msg)) - ceph_msg_data_cursor_init(&msg->p); + ceph_msg_data_cursor_init(&msg->p, data_len); if (ceph_msg_has_pagelist(msg)) - ceph_msg_data_cursor_init(&msg->l); + ceph_msg_data_cursor_init(&msg->l, data_len); msg_pos->did_page_crc = false; } |