Commit 498c48c6 authored by Kairui Song's avatar Kairui Song Committed by Andrew Morton
Browse files

mm, swap: fix reclaim offset calculation error during allocation 

There is a code error that will cause the swap entry allocator to reclaim
and check the whole cluster with an unexpected tail offset instead of the
part that needs to be reclaimed.  This may cause corruption of the swap
map, so fix it.

Link: https://lkml.kernel.org/r/20250130115131.37777-1-ryncsn@gmail.com


Fixes: 3b644773 ("mm, swap: reduce contention on device lock")
Signed-off-by: default avatarKairui Song <kasong@tencent.com>
Cc: Chris Li <chrisl@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 1ccae30e

mm/swapfile.c

+1 −1
Original line number Diff line number Diff line
@@ -794,7 +794,7 @@ static unsigned int alloc_swap_scan_cluster(struct swap_info_struct *si, 
		if (!cluster_scan_range(si, ci, offset, nr_pages, &need_reclaim))

			continue;

		if (need_reclaim) {

			ret = cluster_reclaim_range(si, ci, start, end);

			ret = cluster_reclaim_range(si, ci, offset, offset + nr_pages);

			/*

			 * Reclaim drops ci->lock and cluster could be used

			 * by another order. Not checking flag as off-list