dax: drop size parameter to ->direct_access()

None of the implementations currently use it.  The common
bdev_direct_access() entry point handles all the size checks before
calling ->direct_access().
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

arch/powerpc/sysdev/axonram.c

@@ -141,7 +141,7 @@ axon_ram_make_request(struct request_queue *queue, struct bio *bio)
  */
 static long
 axon_ram_direct_access(struct block_device *device, sector_t sector,
-		       void __pmem **kaddr, unsigned long *pfn, long size)
+		       void __pmem **kaddr, unsigned long *pfn)
 {
 	struct axon_ram_bank *bank = device->bd_disk->private_data;
 	loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT;

drivers/block/brd.c

@@ -371,7 +371,7 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector,
 
 #ifdef CONFIG_BLK_DEV_RAM_DAX
 static long brd_direct_access(struct block_device *bdev, sector_t sector,
-			void __pmem **kaddr, unsigned long *pfn, long size)
+			void __pmem **kaddr, unsigned long *pfn)
 {
 	struct brd_device *brd = bdev->bd_disk->private_data;
 	struct page *page;
@@ -384,10 +384,6 @@ static long brd_direct_access(struct block_device *bdev, sector_t sector,
 	*kaddr = (void __pmem *)page_address(page);
 	*pfn = page_to_pfn(page);
 
-	/*
-	 * TODO: If size > PAGE_SIZE, we could look to see if the next page in
-	 * the file happens to be mapped to the next page of physical RAM.
-	 */
 	return PAGE_SIZE;
 }
 #else

drivers/nvdimm/pmem.c

@@ -92,7 +92,7 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
 }
 
 static long pmem_direct_access(struct block_device *bdev, sector_t sector,
-		      void __pmem **kaddr, unsigned long *pfn, long size)
+		      void __pmem **kaddr, unsigned long *pfn)
 {
 	struct pmem_device *pmem = bdev->bd_disk->private_data;
 	size_t offset = sector << 9;

drivers/s390/block/dcssblk.c

@@ -29,7 +29,7 @@ static int dcssblk_open(struct block_device *bdev, fmode_t mode);
 static void dcssblk_release(struct gendisk *disk, fmode_t mode);
 static void dcssblk_make_request(struct request_queue *q, struct bio *bio);
 static long dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
-			 void __pmem **kaddr, unsigned long *pfn, long size);
+			 void __pmem **kaddr, unsigned long *pfn);
 
 static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
 
@@ -879,7 +879,7 @@ dcssblk_make_request(struct request_queue *q, struct bio *bio)
 
 static long
 dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
-			void __pmem **kaddr, unsigned long *pfn, long size)
+			void __pmem **kaddr, unsigned long *pfn)
 {
 	struct dcssblk_dev_info *dev_info;
 	unsigned long offset, dev_sz;

fs/block_dev.c

@@ -462,7 +462,7 @@ long bdev_direct_access(struct block_device *bdev, sector_t sector,
 	sector += get_start_sect(bdev);
 	if (sector % (PAGE_SIZE / 512))
 		return -EINVAL;
-	avail = ops->direct_access(bdev, sector, addr, pfn, size);
+	avail = ops->direct_access(bdev, sector, addr, pfn);
 	if (!avail)
 		return -ERANGE;
 	return min(avail, size);

include/linux/blkdev.h

@@ -1556,7 +1556,7 @@ struct block_device_operations {
 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
 	long (*direct_access)(struct block_device *, sector_t, void __pmem **,
-			unsigned long *pfn, long size);
+			unsigned long *pfn);
 	unsigned int (*check_events) (struct gendisk *disk,
 				      unsigned int clearing);
 	/* ->media_changed() is DEPRECATED, use ->check_events() instead */