linux-kernel - [PATCH v4 66/66] mm/mmap: Drop range_has

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Message-ID: <20211201142918.921493-67-Liam.Howlett@oracle.com>
Date:   Wed, 1 Dec 2021 14:30:28 +0000
From:   Liam Howlett <liam.howlett@...cle.com>
To:     "maple-tree@...ts.infradead.org" <maple-tree@...ts.infradead.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Andrew Morton <akpm@...ux-foundation.org>
CC:     Song Liu <songliubraving@...com>,
        Davidlohr Bueso <dave@...olabs.net>,
        "Paul E . McKenney" <paulmck@...nel.org>,
        Matthew Wilcox <willy@...radead.org>,
        Laurent Dufour <ldufour@...ux.ibm.com>,
        David Rientjes <rientjes@...gle.com>,
        Axel Rasmussen <axelrasmussen@...gle.com>,
        Suren Baghdasaryan <surenb@...gle.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Rik van Riel <riel@...riel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Michel Lespinasse <walken.cr@...il.com>,
        Jerome Glisse <jglisse@...hat.com>,
        Minchan Kim <minchan@...gle.com>,
        Joel Fernandes <joelaf@...gle.com>,
        Rom Lemarchand <romlem@...gle.com>,
        Liam Howlett <liam.howlett@...cle.com>
Subject: [PATCH v4 66/66] mm/mmap: Drop range_has_overlap() function

From: "Liam R. Howlett" <Liam.Howlett@...cle.com>

Since there is no longer a linked list, the range_has_overlap() function
is identical to the find_vma_intersection() function.  There is only one
place that actually needs the previous vma, so just use vma_prev() in
that one case.

Signed-off-by: Liam R. Howlett <Liam.Howlett@...cle.com>
---
 mm/mmap.c | 28 +---------------------------
 1 file changed, 1 insertion(+), 27 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index e13c6ef76697..4dfe2f92796e 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -420,30 +420,6 @@ anon_vma_interval_tree_post_update_vma(struct vm_area_struct *vma)
 		anon_vma_interval_tree_insert(avc, &avc->anon_vma->rb_root);
 }
 
-/*
- * range_has_overlap() - Check the @start - @end range for overlapping VMAs and
- * sets up a pointer to the previous VMA
- * @mm: the mm struct
- * @start: the start address of the range
- * @end: the end address of the range
- * @pprev: the pointer to the pointer of the previous VMA
- *
- * Returns: True if there is an overlapping VMA, false otherwise
- */
-static inline
-bool range_has_overlap(struct mm_struct *mm, unsigned long start,
-		       unsigned long end, struct vm_area_struct **pprev)
-{
-	struct vm_area_struct *existing;
-
-	MA_STATE(mas, &mm->mm_mt, start, start);
-	rcu_read_lock();
-	existing = mas_find(&mas, end - 1);
-	*pprev = mas_prev(&mas, 0);
-	rcu_read_unlock();
-	return existing ? true : false;
-}
-
 static unsigned long count_vma_pages_range(struct mm_struct *mm,
 		unsigned long addr, unsigned long end)
 {
@@ -3188,9 +3164,7 @@ void exit_mmap(struct mm_struct *mm)
  */
 int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
 {
-	struct vm_area_struct *prev;
-
-	if (range_has_overlap(mm, vma->vm_start, vma->vm_end, &prev))
+	if (find_vma_intersection(mm, vma->vm_start, vma->vm_end))
 		return -ENOMEM;
 
 	if ((vma->vm_flags & VM_ACCOUNT) &&
-- 
2.30.2