The patch below does not apply to the 6.7-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.7.y git checkout FETCH_HEAD git cherry-pick -x 678e54d4bb9a4822f8ae99690ac131c5d490cdb1 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024022622-agony-salvaging-5082@gregkh' --subject-prefix 'PATCH 6.7.y' HEAD^..

Possible dependencies:

678e54d4bb9a ("mm/zswap: invalidate duplicate entry when !zswap_enabled") a65b0e7607cc ("zswap: make shrinking memcg-aware")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 678e54d4bb9a4822f8ae99690ac131c5d490cdb1 Mon Sep 17 00:00:00 2001 From: Chengming Zhou zhouchengming@bytedance.com Date: Thu, 8 Feb 2024 02:32:54 +0000 Subject: [PATCH] mm/zswap: invalidate duplicate entry when !zswap_enabled

We have to invalidate any duplicate entry even when !zswap_enabled since zswap can be disabled anytime. If the folio store success before, then got dirtied again but zswap disabled, we won't invalidate the old duplicate entry in the zswap_store(). So later lru writeback may overwrite the new data in swapfile.

Link: https://lkml.kernel.org/r/20240208023254.3873823-1-chengming.zhou@linux.dev Fixes: 42c06a0e8ebe ("mm: kill frontswap") Signed-off-by: Chengming Zhou zhouchengming@bytedance.com Acked-by: Johannes Weiner hannes@cmpxchg.org Cc: Nhat Pham nphamcs@gmail.com Cc: Yosry Ahmed yosryahmed@google.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org

diff --git a/mm/zswap.c b/mm/zswap.c index 36903d938c15..db4625af65fb 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1518,7 +1518,7 @@ bool zswap_store(struct folio *folio) if (folio_test_large(folio)) return false;

- if (!zswap_enabled || !tree) + if (!tree) return false;

/* @@ -1533,6 +1533,10 @@ bool zswap_store(struct folio *folio) zswap_invalidate_entry(tree, dupentry); } spin_unlock(&tree->lock); + + if (!zswap_enabled) + return false; + objcg = get_obj_cgroup_from_folio(folio); if (objcg && !obj_cgroup_may_zswap(objcg)) { memcg = get_mem_cgroup_from_objcg(objcg);