+ mm-swap-use-swp_solidstate-to-determine-if-swap-is-rotational.patch added to mm-new branch

+ mm-swap-use-swp_solidstate-to-determine-if-swap-is-rotational.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm, swap: use SWP_SOLIDSTATE to determine if swap is rotational
has been added to the -mm mm-new branch.  Its filename is
     mm-swap-use-swp_solidstate-to-determine-if-swap-is-rotational.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap-use-swp_solidstate-to-determine-if-swap-is-rotational.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

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------------------------------------------------------
From: Youngjun Park <youngjun.park@lge.com>
Subject: mm, swap: use SWP_SOLIDSTATE to determine if swap is rotational
Date: Fri, 31 Oct 2025 15:50:08 +0900

The current non rotational check is unreliable as the device's rotational
status can be changed by a user via sysfs.

Use the more reliable SWP_SOLIDSTATE flag which is set at swapon time, to
ensure the nr_rotate_swap count remains consistent.  Plus, it is easy to
read and simple.

Link: https://lkml.kernel.org/r/20251031065011.40863-3-youngjun.park@lge.com
Fixes: 81a0298bdfab ("mm, swap: don't use VMA based swap readahead if HDD is used as swap")
Signed-off-by: Youngjun Park <youngjun.park@lge.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/swapfile.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/swapfile.c~mm-swap-use-swp_solidstate-to-determine-if-swap-is-rotational
+++ a/mm/swapfile.c
@@ -2913,7 +2913,7 @@ SYSCALL_DEFINE1(swapoff, const char __us
 	if (p->flags & SWP_CONTINUED)
 		free_swap_count_continuations(p);
 
-	if (!p->bdev || !bdev_nonrot(p->bdev))
+	if (!(p->flags & SWP_SOLIDSTATE))
 		atomic_dec(&nr_rotate_swap);
 
 	mutex_lock(&swapon_mutex);
_

Patches currently in -mm which might be from youngjun.park@lge.com are

mm-swap-fix-memory-leak-in-setup_clusters-error-path.patch
mm-swap-use-swp_solidstate-to-determine-if-swap-is-rotational.patch
mm-swap-remove-redundant-comment-for-read_swap_cache_async.patch
mm-swap-change-swap_alloc_slow-to-void.patch
mm-swap-remove-scan_swap_map_slots-references-from-comments.patch