@@ -38,7 +38,6 @@ static struct bio *get_swap_bio(gfp_t gfp_flags,
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 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
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, struct writeback_control *wbc,
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, bool synchronous)
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);
@@ -2305,7 +2305,7 @@ 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);
+ return map_swap_entry(entry, bdev) << (PAGE_SHIFT - 9);
}
/*
commit caf6912f3f4af7232340d500a4a2008f81b93f14 upstream. Fix block device sector offset calculation for swap page io on top of blockdevs that provide a rw_page operation and do page-sized io directly (without the block layer). Currently swap_page_sector() maps a swap page into a blockdev sector by obtaining the swap page offset (swap map slot), but ignores the swapfile starting offset into the blockdev. In setups where swapfiles are sitting on top of a filesystem, this results into swapping out activity potentially overwriting filesystem blocks that fall outside the swapfile region. [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()") Cc: stable@vger.kernel.org # 4.14 4.19 Signed-off-by: Anthony Iliopoulos <ailiop@suse.com> --- mm/page_io.c | 11 +++-------- mm/swapfile.c | 2 +- 2 files changed, 4 insertions(+), 9 deletions(-)