From eea9befaccb8d43ce89585d612159761c978f056 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 16 Aug 2007 13:31:26 +0200 Subject: [PATCH] Fix various abuse of bio fields in umem.c umem.c: advances bi_idx and bi_sector to track where it is up to. But it is only ever doing this on one bio, so the updated fields can easily be kept elsewhere (current_*). updates bi_size, but never uses the updated values, so this isn't needed. reuses bi_phys_segments to count how many iovecs have been completely. As the completion happens sequentiually, we can store this information outside the bio too. Signed-off-by: Neil Brown diff .prev/drivers/block/umem.c ./drivers/block/umem.c Signed-off-by: Jens Axboe --- drivers/block/umem.c | 38 +++++++++++++++++++++++++------------- 1 file changed, 25 insertions(+), 13 deletions(-) diff --git a/drivers/block/umem.c b/drivers/block/umem.c index 6b7c02d6360..c378e285d70 100644 --- a/drivers/block/umem.c +++ b/drivers/block/umem.c @@ -113,6 +113,8 @@ struct cardinfo { * have been written */ struct bio *bio, *currentbio, **biotail; + int current_idx; + sector_t current_sector; struct request_queue *queue; @@ -121,6 +123,7 @@ struct cardinfo { struct mm_dma_desc *desc; int cnt, headcnt; struct bio *bio, **biotail; + int idx; } mm_pages[2]; #define DESC_PER_PAGE ((PAGE_SIZE*2)/sizeof(struct mm_dma_desc)) @@ -380,12 +383,16 @@ static int add_bio(struct cardinfo *card) dma_addr_t dma_handle; int offset; struct bio *bio; + struct bio_vec *vec; + int idx; int rw; int len; bio = card->currentbio; if (!bio && card->bio) { card->currentbio = card->bio; + card->current_idx = card->bio->bi_idx; + card->current_sector = card->bio->bi_sector; card->bio = card->bio->bi_next; if (card->bio == NULL) card->biotail = &card->bio; @@ -394,15 +401,17 @@ static int add_bio(struct cardinfo *card) } if (!bio) return 0; + idx = card->current_idx; rw = bio_rw(bio); if (card->mm_pages[card->Ready].cnt >= DESC_PER_PAGE) return 0; - len = bio_iovec(bio)->bv_len; - dma_handle = pci_map_page(card->dev, - bio_page(bio), - bio_offset(bio), + vec = bio_iovec_idx(bio, idx); + len = vec->bv_len; + dma_handle = pci_map_page(card->dev, + vec->bv_page, + vec->bv_offset, len, (rw==READ) ? PCI_DMA_FROMDEVICE : PCI_DMA_TODEVICE); @@ -410,6 +419,8 @@ static int add_bio(struct cardinfo *card) p = &card->mm_pages[card->Ready]; desc = &p->desc[p->cnt]; p->cnt++; + if (p->bio == NULL) + p->idx = idx; if ((p->biotail) != &bio->bi_next) { *(p->biotail) = bio; p->biotail = &(bio->bi_next); @@ -419,7 +430,7 @@ static int add_bio(struct cardinfo *card) desc->data_dma_handle = dma_handle; desc->pci_addr = cpu_to_le64((u64)desc->data_dma_handle); - desc->local_addr= cpu_to_le64(bio->bi_sector << 9); + desc->local_addr = cpu_to_le64(card->current_sector << 9); desc->transfer_size = cpu_to_le32(len); offset = ( ((char*)&desc->sem_control_bits) - ((char*)p->desc)); desc->sem_addr = cpu_to_le64((u64)(p->page_dma+offset)); @@ -435,10 +446,10 @@ static int add_bio(struct cardinfo *card) desc->control_bits |= cpu_to_le32(DMASCR_TRANSFER_READ); desc->sem_control_bits = desc->control_bits; - bio->bi_sector += (len>>9); - bio->bi_size -= len; - bio->bi_idx++; - if (bio->bi_idx >= bio->bi_vcnt) + card->current_sector += (len >> 9); + idx++; + card->current_idx = idx; + if (idx >= bio->bi_vcnt) card->currentbio = NULL; return 1; @@ -474,10 +485,12 @@ static void process_page(unsigned long data) last=1; } page->headcnt++; - idx = bio->bi_phys_segments; - bio->bi_phys_segments++; - if (bio->bi_phys_segments >= bio->bi_vcnt) + idx = page->idx; + page->idx++; + if (page->idx >= bio->bi_vcnt) { page->bio = bio->bi_next; + page->idx = page->bio->bi_idx; + } pci_unmap_page(card->dev, desc->data_dma_handle, bio_iovec_idx(bio,idx)->bv_len, @@ -547,7 +560,6 @@ static int mm_make_request(struct request_queue *q, struct bio *bio) pr_debug("mm_make_request %llu %u\n", (unsigned long long)bio->bi_sector, bio->bi_size); - bio->bi_phys_segments = bio->bi_idx; /* count of completed segments*/ spin_lock_irq(&card->lock); *card->biotail = bio; bio->bi_next = NULL; -- 2.20.1