On 2020/04/07 8:25, Chaitanya Kulkarni wrote:
> The existing routine xfs_rw_bdev has block layer bio-based code which
> maps the data buffer allocated with kmalloc or vmalloc to the READ/WRITE
> bios. Use a block layer helper from the previous patch to avoid code
> duplication.
>
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
> ---
> fs/xfs/xfs_bio_io.c | 47 ++-------------------------------------------
> 1 file changed, 2 insertions(+), 45 deletions(-)
>
> diff --git a/fs/xfs/xfs_bio_io.c b/fs/xfs/xfs_bio_io.c
> index e2148f2d5d6b..b04c398fb99c 100644
> --- a/fs/xfs/xfs_bio_io.c
> +++ b/fs/xfs/xfs_bio_io.c
> @@ -4,11 +4,6 @@
> */
> #include "xfs.h"
>
> -static inline unsigned int bio_max_vecs(unsigned int count)
> -{
> - return min_t(unsigned, howmany(count, PAGE_SIZE), BIO_MAX_PAGES);
> -}
> -
> int
> xfs_rw_bdev(
> struct block_device *bdev,
> @@ -18,44 +13,6 @@ xfs_rw_bdev(
> unsigned int op)
>
> {
> - unsigned int is_vmalloc = is_vmalloc_addr(data);
> - unsigned int left = count;
> - int error;
> - struct bio *bio;
> -
> - if (is_vmalloc && op == REQ_OP_WRITE)
> - flush_kernel_vmap_range(data, count);
> -
> - bio = bio_alloc(GFP_KERNEL, bio_max_vecs(left));
> - bio_set_dev(bio, bdev);
> - bio->bi_iter.bi_sector = sector;
> - bio->bi_opf = op | REQ_META | REQ_SYNC;
> -
> - do {
> - struct page *page = kmem_to_page(data);
> - unsigned int off = offset_in_page(data);
> - unsigned int len = min_t(unsigned, left, PAGE_SIZE - off);
> -
> - while (bio_add_page(bio, page, len, off) != len) {
> - struct bio *prev = bio;
> -
> - bio = bio_alloc(GFP_KERNEL, bio_max_vecs(left));
> - bio_copy_dev(bio, prev);
> - bio->bi_iter.bi_sector = bio_end_sector(prev);
> - bio->bi_opf = prev->bi_opf;
> - bio_chain(prev, bio);
> -
> - submit_bio(prev);
> - }
> -
> - data += len;
> - left -= len;
> - } while (left > 0);
Your helper could use a similar loop structure. This is very easy to read.
> -
> - error = submit_bio_wait(bio);
> - bio_put(bio);
> -
> - if (is_vmalloc && op == REQ_OP_READ)
> - invalidate_kernel_vmap_range(data, count);
> - return error;
> + return blkdev_issue_rw(bdev, data, sector, count, op, REQ_META,
> + GFP_KERNEL);
> }
>
--
Damien Le Moal
Western Digital Research
