[PATCH 4/7] mtd_blkdevs: handle highmem pages

[Christoph Hellwig]

Just kmap the single payload page before passing it on to the FTL.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 drivers/mtd/mtd_blkdevs.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 16ae4ae8e8f9..29c0bfd74e8a 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -82,7 +82,6 @@ static blk_status_t do_blktrans_request(struct 
mtd_blktrans_ops *tr,
 
        block = blk_rq_pos(req) << 9 >> tr->blkshift;
        nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
-       buf = bio_data(req->bio);
 
        if (req_op(req) == REQ_OP_FLUSH) {
                if (tr->flush(dev))
@@ -100,9 +99,14 @@ static blk_status_t do_blktrans_request(struct 
mtd_blktrans_ops *tr,
                        return BLK_STS_IOERR;
                return BLK_STS_OK;
        case REQ_OP_READ:
-               for (; nsect > 0; nsect--, block++, buf += tr->blksize)
-                       if (tr->readsect(dev, block, buf))
+               buf = kmap(bio_page(req->bio)) + bio_offset(req->bio);
+               for (; nsect > 0; nsect--, block++, buf += tr->blksize) {
+                       if (tr->readsect(dev, block, buf)) {
+                               kunmap(bio_page(req->bio));
                                return BLK_STS_IOERR;
+                       }
+               }
+               kunmap(bio_page(req->bio));
                rq_flush_dcache_pages(req);
                return BLK_STS_OK;
        case REQ_OP_WRITE:
@@ -110,9 +114,14 @@ static blk_status_t do_blktrans_request(struct 
mtd_blktrans_ops *tr,
                        return BLK_STS_IOERR;
 
                rq_flush_dcache_pages(req);
-               for (; nsect > 0; nsect--, block++, buf += tr->blksize)
-                       if (tr->writesect(dev, block, buf))
+               buf = kmap(bio_page(req->bio)) + bio_offset(req->bio);
+               for (; nsect > 0; nsect--, block++, buf += tr->blksize) {
+                       if (tr->writesect(dev, block, buf)) {
+                               kunmap(bio_page(req->bio));
                                return BLK_STS_IOERR;
+                       }
+               }
+               kunmap(bio_page(req->bio));
                return BLK_STS_OK;
        default:
                return BLK_STS_IOERR;
@@ -418,7 +427,6 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
        new->rq->queuedata = new;
        blk_queue_logical_block_size(new->rq, tr->blksize);
 
-       blk_queue_bounce_limit(new->rq, BLK_BOUNCE_HIGH);
        blk_queue_flag_set(QUEUE_FLAG_NONROT, new->rq);
        blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, new->rq);
 
-- 
2.17.0