[PATCH v2 7/7] fs: remove rw_page

[Minchan Kim]

Currently, there is no user of rw_page so remove it.

Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
 fs/block_dev.c         | 76 --------------------------------------------------
 fs/mpage.c             | 15 ----------
 include/linux/blkdev.h |  4 ---
 mm/page_io.c           | 17 -----------
 4 files changed, 112 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 9941dc8342df..6fb408041e7d 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -649,82 +649,6 @@ int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
 }
 EXPORT_SYMBOL(blkdev_fsync);
 
-/**
- * bdev_read_page() - Start reading a page from a block device
- * @bdev: The device to read the page from
- * @sector: The offset on the device to read the page to (need not be aligned)
- * @page: The page to read
- *
- * On entry, the page should be locked.  It will be unlocked when the page
- * has been read.  If the block driver implements rw_page synchronously,
- * that will be true on exit from this function, but it need not be.
- *
- * Errors returned by this function are usually "soft", eg out of memory, or
- * queue full; callers should try a different route to read this page rather
- * than propagate an error back up the stack.
- *
- * Return: negative errno if an error occurs, 0 if submission was successful.
- */
-int bdev_read_page(struct block_device *bdev, sector_t sector,
-			struct page *page)
-{
-	const struct block_device_operations *ops = bdev->bd_disk->fops;
-	int result = -EOPNOTSUPP;
-
-	if (!ops->rw_page || bdev_get_integrity(bdev))
-		return result;
-
-	result = blk_queue_enter(bdev->bd_queue, false);
-	if (result)
-		return result;
-	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, false);
-	blk_queue_exit(bdev->bd_queue);
-	return result;
-}
-EXPORT_SYMBOL_GPL(bdev_read_page);
-
-/**
- * bdev_write_page() - Start writing a page to a block device
- * @bdev: The device to write the page to
- * @sector: The offset on the device to write the page to (need not be aligned)
- * @page: The page to write
- * @wbc: The writeback_control for the write
- *
- * On entry, the page should be locked and not currently under writeback.
- * On exit, if the write started successfully, the page will be unlocked and
- * under writeback.  If the write failed already (eg the driver failed to
- * queue the page to the device), the page will still be locked.  If the
- * caller is a ->writepage implementation, it will need to unlock the page.
- *
- * Errors returned by this function are usually "soft", eg out of memory, or
- * queue full; callers should try a different route to write this page rather
- * than propagate an error back up the stack.
- *
- * Return: negative errno if an error occurs, 0 if submission was successful.
- */
-int bdev_write_page(struct block_device *bdev, sector_t sector,
-			struct page *page, struct writeback_control *wbc)
-{
-	int result;
-	const struct block_device_operations *ops = bdev->bd_disk->fops;
-
-	if (!ops->rw_page || bdev_get_integrity(bdev))
-		return -EOPNOTSUPP;
-	result = blk_queue_enter(bdev->bd_queue, false);
-	if (result)
-		return result;
-
-	set_page_writeback(page);
-	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, true);
-	if (result)
-		end_page_writeback(page);
-	else
-		unlock_page(page);
-	blk_queue_exit(bdev->bd_queue);
-	return result;
-}
-EXPORT_SYMBOL_GPL(bdev_write_page);
-
 /*
  * pseudo-fs
  */
diff --git a/fs/mpage.c b/fs/mpage.c
index d3b777fdfd5a..31282ea5d6db 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -280,12 +280,6 @@ do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages,
 
 alloc_new:
 	if (bio == NULL) {
-		if (first_hole == blocks_per_page) {
-			if (!bdev_read_page(bdev, blocks[0] << (blkbits - 9),
-								page))
-				goto out;
-		}
-
 		if (bdi_cap_synchronous_io(inode_to_bdi(inode))) {
 			bio = &sbio;
 			/* mpage_end_io calls bio_put unconditionally */
@@ -623,14 +617,6 @@ static int __mpage_writepage(struct page *page, struct writeback_control *wbc,
 
 alloc_new:
 	if (bio == NULL) {
-		if (first_unmapped == blocks_per_page) {
-			if (!bdev_write_page(bdev, blocks[0] << (blkbits - 9),
-								page, wbc)) {
-				clean_buffers(page, first_unmapped);
-				goto out;
-			}
-		}
-
 		if (bdi_cap_synchronous_io(inode_to_bdi(inode))) {
 			bio = &sbio;
 			/* mpage_end_io calls bio_put unconditionally */
@@ -645,7 +631,6 @@ static int __mpage_writepage(struct page *page, struct writeback_control *wbc,
 			if (bio == NULL)
 				goto confused;
 		}
-
 		wbc_init_bio(wbc, bio);
 		bio->bi_write_hint = inode->i_write_hint;
 	}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 25f6a0cb27d3..21fffa849033 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1936,7 +1936,6 @@ static inline bool integrity_req_gap_front_merge(struct request *req,
 struct block_device_operations {
 	int (*open) (struct block_device *, fmode_t);
 	void (*release) (struct gendisk *, fmode_t);
-	int (*rw_page)(struct block_device *, sector_t, struct page *, bool);
 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
 	unsigned int (*check_events) (struct gendisk *disk,
@@ -1954,9 +1953,6 @@ struct block_device_operations {
 
 extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
 				 unsigned long);
-extern int bdev_read_page(struct block_device *, sector_t, struct page *);
-extern int bdev_write_page(struct block_device *, sector_t, struct page *,
-						struct writeback_control *);
 #else /* CONFIG_BLOCK */
 
 struct block_device;
diff --git a/mm/page_io.c b/mm/page_io.c
index 64330c751548..a70874f9cb18 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -324,12 +324,6 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc)
 		return ret;
 	}
 
-	ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, wbc);
-	if (!ret) {
-		count_swpout_vm_event(page);
-		return 0;
-	}
-
 	ret = 0;
 	if (!(sis->flags & SWP_SYNC_IO)) {
 
@@ -390,17 +384,6 @@ int swap_readpage(struct page *page, bool do_poll)
 		return ret;
 	}
 
-	ret = bdev_read_page(sis->bdev, swap_page_sector(page), page);
-	if (!ret) {
-		if (trylock_page(page)) {
-			swap_slot_free_notify(page);
-			unlock_page(page);
-		}
-
-		count_vm_event(PSWPIN);
-		return 0;
-	}
-
 	ret = 0;
 	count_vm_event(PSWPIN);
 	if (!(sis->flags & SWP_SYNC_IO)) {
-- 
2.7.4