linux-2.6.25/__blk_queue_bounce() の履歴(No.20)

参照元†

linux-2.6.25/blk_queue_bounce()

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説明†

パス: linux-2.6.25/linux-2.6.25/mm/bounce.c

FIXME: これは何？
- 説明

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引数†

struct request_queue *q
struct bio **bio_orig
mempool_t *pool

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返り値†

なし

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参考†

↑

実装†

static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
                               mempool_t *pool)
{
        struct page *page;
        struct bio *bio = NULL;
        int i, rw = bio_data_dir(*bio_orig);
        struct bio_vec *to, *from;

        bio_for_each_segment(from, *bio_orig, i) {
                page = from->bv_page;

- linux-2.6.25/bio_for_each_segment()

                /*
                 * is destination page below bounce pfn?
                 */
                if (page_to_pfn(page) <= q->bounce_pfn)
                        continue;

- linux-2.6.25/page_to_pfn()

                /*
                 * irk, bounce it
                 */
                if (!bio)
                        bio = bio_alloc(GFP_NOIO, (*bio_orig)->bi_vcnt);

- linux-2.6.25/bio_alloc()

                to = bio->bi_io_vec + i;

                to->bv_page = mempool_alloc(pool, q->bounce_gfp);
                to->bv_len = from->bv_len;
                to->bv_offset = from->bv_offset;
                inc_zone_page_state(to->bv_page, NR_BOUNCE);

- linux-2.6.25/mempool_alloc()
- linux-2.6.25/inc_zone_page_state()

                if (rw == WRITE) {
                        char *vto, *vfrom;

                        flush_dcache_page(from->bv_page);
                        vto = page_address(to->bv_page) + to->bv_offset;
                        vfrom = kmap(from->bv_page) + from->bv_offset;
                        memcpy(vto, vfrom, to->bv_len);
                        kunmap(from->bv_page);

                }
        }

        /*
         * no pages bounced
         */
        if (!bio)
                return;

        blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE);

- linux-2.6.25/blk_add_trace_bio()

        /*
         * at least one page was bounced, fill in possible non-highmem
         * pages
         */
        __bio_for_each_segment(from, *bio_orig, i, 0) {

- linux-2.6.25/__bio_for_each_segment()

                to = bio_iovec_idx(bio, i);
                if (!to->bv_page) {
                        to->bv_page = from->bv_page;
                        to->bv_len = from->bv_len;
                        to->bv_offset = from->bv_offset;
                }

- linux-2.6.25/bio_iovec_idx()

        }

        bio->bi_bdev = (*bio_orig)->bi_bdev;
        bio->bi_flags |= (1 << BIO_BOUNCED);
        bio->bi_sector = (*bio_orig)->bi_sector;
        bio->bi_rw = (*bio_orig)->bi_rw;

        bio->bi_vcnt = (*bio_orig)->bi_vcnt;
        bio->bi_idx = (*bio_orig)->bi_idx;
        bio->bi_size = (*bio_orig)->bi_size;

        if (pool == page_pool) {
                bio->bi_end_io = bounce_end_io_write;
                if (rw == READ)
                        bio->bi_end_io = bounce_end_io_read;
        } else {
                bio->bi_end_io = bounce_end_io_write_isa;
                if (rw == READ)
                        bio->bi_end_io = bounce_end_io_read_isa;
        }

        bio->bi_private = *bio_orig;
        *bio_orig = bio;
}

↑

linux-2.6.25/__blk_queue_bounce() の履歴(No.20)

参照元†

説明†

引数†

返り値†

参考†

実装†

コメント†