Commit 48d15436 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

mm: remove get_swap_bio 



Just reuse the block_device and sector from the swap_info structure,
just as used by the SWP_SYNCHRONOUS path.  Also remove the checks for
NULL returns from bio_alloc as that can't happen for sleeping
allocations.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 64820ac6

include/linux/swap.h

+0 −1
Original line number Diff line number Diff line
@@ -468,7 +468,6 @@ extern int free_swap_and_cache(swp_entry_t); 
int swap_type_of(dev_t device, sector_t offset);

int find_first_swap(dev_t *device);

extern unsigned int count_swap_pages(int, int);

extern sector_t map_swap_page(struct page *, struct block_device **);

extern sector_t swapdev_block(int, pgoff_t);

extern int page_swapcount(struct page *);

extern int __swap_count(swp_entry_t entry);

mm/page_io.c

+13 −32
Original line number Diff line number Diff line
@@ -26,25 +26,6 @@ 
#include <linux/uio.h>

#include <linux/sched/task.h>



static struct bio *get_swap_bio(gfp_t gfp_flags,

				struct page *page, bio_end_io_t end_io)

{

	struct bio *bio;



	bio = bio_alloc(gfp_flags, 1);

	if (bio) {

		struct block_device *bdev;



		bio->bi_iter.bi_sector = map_swap_page(page, &bdev);

		bio_set_dev(bio, bdev);

		bio->bi_iter.bi_sector <<= PAGE_SHIFT - 9;

		bio->bi_end_io = end_io;



		bio_add_page(bio, page, thp_size(page), 0);

	}

	return bio;

}



void end_swap_bio_write(struct bio *bio)

{

	struct page *page = bio_first_page_all(bio);
@@ -361,13 +342,13 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc, 
		return 0;

	}



	bio = get_swap_bio(GFP_NOIO, page, end_write_func);

	if (bio == NULL) {

		set_page_dirty(page);

		unlock_page(page);

		return -ENOMEM;

	}

	bio = bio_alloc(GFP_NOIO, 1);

	bio_set_dev(bio, sis->bdev);

	bio->bi_iter.bi_sector = swap_page_sector(page);

	bio->bi_opf = REQ_OP_WRITE | REQ_SWAP | wbc_to_write_flags(wbc);

	bio->bi_end_io = end_write_func;

	bio_add_page(bio, page, thp_size(page), 0);



	bio_associate_blkg_from_page(bio, page);

	count_swpout_vm_event(page);

	set_page_writeback(page);
@@ -427,18 +408,18 @@ int swap_readpage(struct page *page, bool synchronous) 
	}



	ret = 0;

	bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);

	if (bio == NULL) {

		unlock_page(page);

		ret = -ENOMEM;

		goto out;

	}

	bio = bio_alloc(GFP_KERNEL, 1);

	bio_set_dev(bio, sis->bdev);

	bio->bi_opf = REQ_OP_READ;

	bio->bi_iter.bi_sector = swap_page_sector(page);

	bio->bi_end_io = end_swap_bio_read;

	bio_add_page(bio, page, thp_size(page), 0);



	disk = bio->bi_bdev->bd_disk;

	/*

	 * Keep this task valid during swap readpage because the oom killer may

	 * attempt to access it in the page fault retry time check.

	 */

	bio_set_op_attrs(bio, REQ_OP_READ, 0);

	if (synchronous) {

		bio->bi_opf |= REQ_HIPRI;

		get_task_struct(current);

mm/swapfile.c

+0 −10
Original line number Diff line number Diff line
@@ -2301,16 +2301,6 @@ static sector_t map_swap_entry(swp_entry_t entry, struct block_device **bdev) 
	return se->start_block + (offset - se->start_page);

}



/*

 * Returns the page offset into bdev for the specified page's swap entry.

 */

sector_t map_swap_page(struct page *page, struct block_device **bdev)

{

	swp_entry_t entry;

	entry.val = page_private(page);

	return map_swap_entry(entry, bdev);

}



/*

 * Free all of a swapdev's extent information

 */