FROMGIT: BACKPORT: Multi-gen LRU: Fix can_swap in lru_gen_look_around()

walk->can_swap might be invalid since it's not guaranteed to be
initialized for the particular lruvec.  Instead deduce it from the folio
type (anon/file).

Link: https://lkml.kernel.org/r/20230802025606.346758-3-kaleshsingh@google.com


Fixes: 018ee47f ("mm: multi-gen LRU: exploit locality in rmap")
Change-Id: I1ae78011d4972d87bac9f2db8c56352cdb7a9be6
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> [mediatek]
Tested-by: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Aneesh Kumar K V <aneesh.kumar@linux.ibm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Steven Barrett <steven@liquorix.net>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit fdf19e8c8f1cdcee4eccf4c98a875f44f39d8b9d https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git

 mm-unstable)
Bug: 288383787
Bug: 291719697
[ Kalesh Singh - Fix trivial conflict in lru_gen_look_around() ]
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>