[PATCH 2/3] pmem: remove pmem_rw_page()

[Ross Zwisler]

The rw_page() interface doesn't provide a clear performance benefit for
PMEM and has had a nonzero maintenance burden, so remove it.

Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
---
 drivers/nvdimm/pmem.c | 21 ---------------------
 1 file changed, 21 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index f7099ada..f23c82d 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -182,26 +182,6 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
 	return BLK_QC_T_NONE;
 }
 
-static int pmem_rw_page(struct block_device *bdev, sector_t sector,
-		       struct page *page, bool is_write)
-{
-	struct pmem_device *pmem = bdev->bd_queue->queuedata;
-	blk_status_t rc;
-
-	rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, sector);
-
-	/*
-	 * The ->rw_page interface is subtle and tricky.  The core
-	 * retries on any error, so we can only invoke page_endio() in
-	 * the successful completion case.  Otherwise, we'll see crashes
-	 * caused by double completion.
-	 */
-	if (rc == 0)
-		page_endio(page, is_write, 0);
-
-	return blk_status_to_errno(rc);
-}
-
 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
 __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 		long nr_pages, void **kaddr, pfn_t *pfn)
@@ -225,7 +205,6 @@ __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 
 static const struct block_device_operations pmem_fops = {
 	.owner =		THIS_MODULE,
-	.rw_page =		pmem_rw_page,
 	.revalidate_disk =	nvdimm_revalidate_disk,
 };
 
-- 
2.9.4