[PATCH 05/11] mm: page_vma_mapped_walk(): prettify PVMW_MIGRATION block

[Hugh Dickins]

page_vma_mapped_walk() cleanup: rearrange the !pmd_present() block to
follow the same "return not_found, return not_found, return true" pattern
as the block above it (note: returning not_found there is never premature,
since existence or prior existence of huge pmd guarantees good alignment).

Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
 mm/page_vma_mapped.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 81000dd0b5da..b96fae568bc2 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -201,24 +201,22 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
 			if (pmd_page(pmde) != page)
 				return not_found(pvmw);
 			return true;
-		} else if (!pmd_present(pmde)) {
-			if (thp_migration_supported()) {
-				if (!(pvmw->flags & PVMW_MIGRATION))
-					return not_found(pvmw);
-				if (is_migration_entry(pmd_to_swp_entry(pmde))) {
-					swp_entry_t entry = pmd_to_swp_entry(pmde);
+		}
+		if (!pmd_present(pmde)) {
+			swp_entry_t entry;
 
-					if (migration_entry_to_page(entry) != page)
-						return not_found(pvmw);
-					return true;
-				}
-			}
-			return not_found(pvmw);
-		} else {
-			/* THP pmd was split under us: handle on pte level */
-			spin_unlock(pvmw->ptl);
-			pvmw->ptl = NULL;
+			if (!thp_migration_supported() ||
+			    !(pvmw->flags & PVMW_MIGRATION))
+				return not_found(pvmw);
+			entry = pmd_to_swp_entry(pmde);
+			if (!is_migration_entry(entry) ||
+			    migration_entry_to_page(entry) != page)
+				return not_found(pvmw);
+			return true;
 		}
+		/* THP pmd was split under us: handle on pte level */
+		spin_unlock(pvmw->ptl);
+		pvmw->ptl = NULL;
 	} else if (!pmd_present(pmde)) {
 		/*
 		 * If PVMW_SYNC, take and drop THP pmd lock so that we
-- 
2.26.2