mm: convert vma_lookup() to use mtree_load()

Unlike the rbtree, the Maple Tree will return a NULL if there's nothing at
a particular address.

Since the previous commit dropped the vmacache, it is now possible to
consult the tree directly.

Link: https://lkml.kernel.org/r/20220504011345.662299-11-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220621204632.3370049-27-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 55b4b53895e80a49cb3fda9cccbfa587a52b255a..a250fd86fde90852c8cf702d5e5bf871feb5f10d 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2809,12 +2809,7 @@ struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
 static inline
 struct vm_area_struct *vma_lookup(struct mm_struct *mm, unsigned long addr)
 {
-       struct vm_area_struct *vma = find_vma(mm, addr);
-
-       if (vma && addr < vma->vm_start)
-               vma = NULL;
-
-       return vma;
+       return mtree_load(&mm->mm_mt, addr);
 }
 
 static inline unsigned long vm_start_gap(struct vm_area_struct *vma)