From: Yang Shi <shy828301@xxxxxxxxx>
Subject: Revert "mm: swap: check if swap backing device is congested or not"
Due to the change about how block layer detects congestion the
justification of commit 8fd2e0b505d1 ("mm: swap: check if swap backing
device is congested or not") doesn't stand anymore, so the commit could be
just reverted in order to solve the race reported by commit 2efa33fc7f6e
("mm/shmem: fix shmem_swapin() race with swapoff"). The fix was reverted
by the previous patch.
Link: https://lkml.kernel.org/r/20210810202936.2672-3-shy828301@xxxxxxxxx
Signed-off-by: Yang Shi <shy828301@xxxxxxxxx>
Suggested-by: Hugh Dickins <hughd@xxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swap_state.c | 7 -------
1 file changed, 7 deletions(-)
--- a/mm/swap_state.c~revert-mm-swap-check-if-swap-backing-device-is-congested-or-not
+++ a/mm/swap_state.c
@@ -628,13 +628,6 @@ struct page *swap_cluster_readahead(swp_
if (!mask)
goto skip;
- /* Test swap type to make sure the dereference is safe */
- if (likely(si->flags & (SWP_BLKDEV | SWP_FS_OPS))) {
- struct inode *inode = si->swap_file->f_mapping->host;
- if (inode_read_congested(inode))
- goto skip;
- }
-
do_poll = false;
/* Read a page_cluster sized and aligned cluster around offset. */
start_offset = offset & ~mask;
_
