FAILED: patch "[PATCH] mm/zswap: invalidate duplicate entry when !zswap_enabled" failed to apply to 6.6-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.6-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-6.6.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-resent-ripeness-43f1@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

678e54d4bb9a ("mm/zswap: invalidate duplicate entry when !zswap_enabled")
a65b0e7607cc ("zswap: make shrinking memcg-aware")
ddc1a5cbc05d ("mempolicy: alloc_pages_mpol() for NUMA policy without vma")
23e4883248f0 ("mm: add page_rmappable_folio() wrapper")
c36f6e6dff4d ("mempolicy trivia: slightly more consistent naming")
7f1ee4e20708 ("mempolicy trivia: delete those ancient pr_debug()s")
1cb5d11a370f ("mempolicy: fix migrate_pages(2) syscall return nr_failed")
3657fdc2451a ("mm: move vma_policy() and anon_vma_name() decls to mm_types.h")
3022fd7af960 ("shmem: _add_to_page_cache() before shmem_inode_acct_blocks()")
054a9f7ccd0a ("shmem: move memcg charge out of shmem_add_to_page_cache()")
4199f51a7eb2 ("shmem: shmem_acct_blocks() and shmem_inode_acct_blocks()")
e3e1a5067fd2 ("shmem: remove vma arg from shmem_get_folio_gfp()")
75c70128a673 ("mm: mempolicy: make mpol_misplaced() to take a folio")
cda6d93672ac ("mm: memory: make numa_migrate_prep() to take a folio")
6695cf68b15c ("mm: memory: use a folio in do_numa_page()")
667ffc31aa95 ("mm: huge_memory: use a folio in do_huge_pmd_numa_page()")
73eab3ca481e ("mm: migrate: convert migrate_misplaced_page() to migrate_misplaced_folio()")
2ac9e99f3b21 ("mm: migrate: convert numamigrate_isolate_page() to numamigrate_isolate_folio()")

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);