From: Jens Axboe axboe@kernel.dk
commit caf6912f3f4af7232340d500a4a2008f81b93f14 upstream.
We're not factoring in the start of the file for where to write and read the swapfile, which leads to very unfortunate side effects of writing where we should not be...
[This issue only affects swapfiles on filesystems on top of blockdevs that implement rw_page ops (brd, zram, btt, pmem), and not on top of any other block devices, in contrast to the upstream commit fix.]
Fixes: dd6bd0d9c7db ("swap: use bdev_read_page() / bdev_write_page()") Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Anthony Iliopoulos ailiop@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/page_io.c | 11 +++-------- mm/swapfile.c | 2 +- 2 files changed, 4 insertions(+), 9 deletions(-)
--- a/mm/page_io.c +++ b/mm/page_io.c @@ -38,7 +38,6 @@ static struct bio *get_swap_bio(gfp_t gf
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;
for (i = 0; i < nr; i++) @@ -262,11 +261,6 @@ out: return ret; }
-static sector_t swap_page_sector(struct page *page) -{ - return (sector_t)__page_file_index(page) << (PAGE_SHIFT - 9); -} - static inline void count_swpout_vm_event(struct page *page) { #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -325,7 +319,8 @@ int __swap_writepage(struct page *page, return ret; }
- ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, wbc); + ret = bdev_write_page(sis->bdev, map_swap_page(page, &sis->bdev), + page, wbc); if (!ret) { count_swpout_vm_event(page); return 0; @@ -376,7 +371,7 @@ int swap_readpage(struct page *page, boo return ret; }
- ret = bdev_read_page(sis->bdev, swap_page_sector(page), page); + ret = bdev_read_page(sis->bdev, map_swap_page(page, &sis->bdev), page); if (!ret) { if (trylock_page(page)) { swap_slot_free_notify(page); --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2305,7 +2305,7 @@ sector_t map_swap_page(struct page *page { swp_entry_t entry; entry.val = page_private(page); - return map_swap_entry(entry, bdev); + return map_swap_entry(entry, bdev) << (PAGE_SHIFT - 9); }
/*