[PATCH 3/4] md/md-llbitmap: unmap sb page before freeing it

[Mykola Marzhan]

Every path in llbitmap_read_sb() that maps the superblock page ends
at the out_put_page label, which frees the page and only then unmaps
it:

	__free_page(sb_page);
	kunmap_local(sb);

The page comes from alloc_page(GFP_KERNEL), so kunmap_local() is
currently a no-op everywhere except CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
builds -- where the page really is freed while a live mapping still
points at it.  Unmap before freeing.

Fixes: 5ab829f1971d ("md/md-llbitmap: introduce new lockless bitmap")
Assisted-by: Claude-Code:claude-opus-4-8
Signed-off-by: Mykola Marzhan <mykola@xxxxxxxxxxx>
---
 drivers/md/md-llbitmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/md-llbitmap.c b/drivers/md/md-llbitmap.c
index 0b591124dc63..63ff2c0d8b43 100644
--- a/drivers/md/md-llbitmap.c
+++ b/drivers/md/md-llbitmap.c
@@ -1035,8 +1035,8 @@ static int llbitmap_read_sb(struct llbitmap *llbitmap)
 	ret = llbitmap_cache_pages(llbitmap);
 
 out_put_page:
-	__free_page(sb_page);
 	kunmap_local(sb);
+	__free_page(sb_page);
 	return ret;
 }
 
-- 
2.43.0