[PATCH v1 5/6] zram: remove zram_rw_page

Minchan Kim
2017-08-08T06:50:39Z

With on-stack-bio, rw_page interface doesn't provide a clear performance
benefit for zram and surely has a maintenance burden, so remove the
last user to remove rw_page completely.

Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
drivers/block/zram/zram_drv.c | 52 -------------------------------------------
1 file changed, 52 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 3eda88d0ca95..9620163308fa 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1268,57 +1268,6 @@ static void zram_slot_free_notify(struct block_device *bdev,
atomic64_inc(&zram->stats.notify_free);
}

-static int zram_rw_page(struct block_device *bdev, sector_t sector,
- struct page *page, bool is_write)
-{
- int offset, ret;
- u32 index;
- struct zram *zram;
- struct bio_vec bv;
-
- if (PageTransHuge(page))
- return -ENOTSUPP;
- zram = bdev->bd_disk->private_data;
-
- if (!valid_io_request(zram, sector, PAGE_SIZE)) {
- atomic64_inc(&zram->stats.invalid_io);
- ret = -EINVAL;
- goto out;
- }
-
- index = sector >> SECTORS_PER_PAGE_SHIFT;
- offset = (sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT;
-
- bv.bv_page = page;
- bv.bv_len = PAGE_SIZE;
- bv.bv_offset = 0;
-
- ret = zram_bvec_rw(zram, &bv, index, offset, is_write, NULL);
-out:
- /*
- * If I/O fails, just return error(ie, non-zero) without
- * calling page_endio.
- * It causes resubmit the I/O with bio request by upper functions
- * of rw_page(e.g., swap_readpage, __swap_writepage) and
- * bio->bi_end_io does things to handle the error
- * (e.g., SetPageError, set_page_dirty and extra works).
- */
- if (unlikely(ret < 0))
- return ret;
-
- switch (ret) {
- case 0:
- page_endio(page, is_write, 0);
- break;
- case 1:
- ret = 0;
- break;
- default:
- WARN_ON(1);
- }
- return ret;
-}
-
static void zram_reset_device(struct zram *zram)
{
struct zcomp *comp;
@@ -1460,7 +1409,6 @@ static int zram_open(struct block_device *bdev, fmode_t mode)
static const struct block_device_operations zram_devops = {
.open = zram_open,
.swap_slot_free_notify = zram_slot_free_notify,
- .rw_page = zram_rw_page,
.owner = THIS_MODULE
};

--
2.7.4