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From:   Liam Howlett <liam.howlett@oracle.com>
To:     "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
CC:     Song Liu <songliubraving@fb.com>,
        Davidlohr Bueso <dave@stgolabs.net>,
        "Paul E . McKenney" <paulmck@kernel.org>,
        Matthew Wilcox <willy@infradead.org>,
        Laurent Dufour <ldufour@linux.ibm.com>,
        David Rientjes <rientjes@google.com>,
        Axel Rasmussen <axelrasmussen@google.com>,
        Suren Baghdasaryan <surenb@google.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Rik van Riel <riel@surriel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Michel Lespinasse <walken.cr@gmail.com>,
        Liam Howlett <liam.howlett@oracle.com>
Subject: [PATCH 66/94] fs/proc/task_mmu: Stop using linked list and
 highest_vm_end
Thread-Topic: [PATCH 66/94] fs/proc/task_mmu: Stop using linked list and
 highest_vm_end
Thread-Index: AQHXPEQ8/XMOfQht/0y2Sh23XT1RFg==
Date:   Wed, 28 Apr 2021 15:36:20 +0000
Message-ID: <20210428153542.2814175-67-Liam.Howlett@Oracle.com>
References: <20210428153542.2814175-1-Liam.Howlett@Oracle.com>
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Remove references to mm_struct linked list and highest_vm_end for when they=
 are removed

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---
 fs/proc/task_mmu.c | 44 ++++++++++++++++++++++++++------------------
 1 file changed, 26 insertions(+), 18 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 503e1355cf6e..f7ce3cc60cc7 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -164,14 +164,13 @@ static void *m_start(struct seq_file *m, loff_t *ppos=
)
 static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
 {
 	struct proc_maps_private *priv =3D m->private;
-	struct vm_area_struct *next, *vma =3D v;
+	struct vm_area_struct *next =3D NULL, *vma =3D v;
=20
-	if (vma =3D=3D priv->tail_vma)
-		next =3D NULL;
-	else if (vma->vm_next)
-		next =3D vma->vm_next;
-	else
-		next =3D priv->tail_vma;
+	if (vma !=3D priv->tail_vma) {
+		next =3D vma_next(vma->vm_mm, vma);
+		if (!next)
+			next =3D priv->tail_vma;
+	}
=20
 	*ppos =3D next ? next->vm_start : -1UL;
=20
@@ -844,16 +843,16 @@ static int show_smaps_rollup(struct seq_file *m, void=
 *v)
 {
 	struct proc_maps_private *priv =3D m->private;
 	struct mem_size_stats mss;
-	struct mm_struct *mm;
+	struct mm_struct *mm =3D priv->mm;
 	struct vm_area_struct *vma;
-	unsigned long last_vma_end =3D 0;
+	unsigned long vma_start =3D 0, last_vma_end =3D 0;
 	int ret =3D 0;
+	MA_STATE(mas, &mm->mm_mt, 0, 0);
=20
 	priv->task =3D get_proc_task(priv->inode);
 	if (!priv->task)
 		return -ESRCH;
=20
-	mm =3D priv->mm;
 	if (!mm || !mmget_not_zero(mm)) {
 		ret =3D -ESRCH;
 		goto out_put_task;
@@ -866,8 +865,13 @@ static int show_smaps_rollup(struct seq_file *m, void =
*v)
 		goto out_put_mm;
=20
 	hold_task_mempolicy(priv);
+	vma =3D mas_find(&mas, 0);
+
+	if (unlikely(!vma))
+		goto empty_set;
=20
-	for (vma =3D priv->mm->mmap; vma;) {
+	vma_start =3D vma->vm_start;
+	do {
 		smap_gather_stats(vma, &mss, 0);
 		last_vma_end =3D vma->vm_end;
=20
@@ -876,6 +880,7 @@ static int show_smaps_rollup(struct seq_file *m, void *=
v)
 		 * access it for write request.
 		 */
 		if (mmap_lock_is_contended(mm)) {
+			mas_pause(&mas);
 			mmap_read_unlock(mm);
 			ret =3D mmap_read_lock_killable(mm);
 			if (ret) {
@@ -919,7 +924,8 @@ static int show_smaps_rollup(struct seq_file *m, void *=
v)
 			 *    contains last_vma_end.
 			 *    Iterate VMA' from last_vma_end.
 			 */
-			vma =3D find_vma(mm, last_vma_end - 1);
+			mas.index =3D mas.last =3D last_vma_end - 1;
+			vma =3D mas_find(&mas, ULONG_MAX);
 			/* Case 3 above */
 			if (!vma)
 				break;
@@ -933,11 +939,10 @@ static int show_smaps_rollup(struct seq_file *m, void=
 *v)
 				smap_gather_stats(vma, &mss, last_vma_end);
 		}
 		/* Case 2 above */
-		vma =3D vma->vm_next;
-	}
+	} while ((vma =3D mas_find(&mas, ULONG_MAX)) !=3D NULL);
=20
-	show_vma_header_prefix(m, priv->mm->mmap->vm_start,
-			       last_vma_end, 0, 0, 0, 0);
+empty_set:
+	show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
 	seq_pad(m, ' ');
 	seq_puts(m, "[rollup]\n");
=20
@@ -1230,6 +1235,7 @@ static ssize_t clear_refs_write(struct file *file, co=
nst char __user *buf,
 		return -ESRCH;
 	mm =3D get_task_mm(task);
 	if (mm) {
+		MA_STATE(mas, &mm->mm_mt, 0, 0);
 		struct mmu_notifier_range range;
 		struct clear_refs_private cp =3D {
 			.type =3D type,
@@ -1249,19 +1255,21 @@ static ssize_t clear_refs_write(struct file *file, =
const char __user *buf,
 		}
=20
 		if (type =3D=3D CLEAR_REFS_SOFT_DIRTY) {
-			for (vma =3D mm->mmap; vma; vma =3D vma->vm_next) {
+			mas_lock(&mas);
+			mas_for_each(&mas, vma, ULONG_MAX) {
 				if (!(vma->vm_flags & VM_SOFTDIRTY))
 					continue;
 				vma->vm_flags &=3D ~VM_SOFTDIRTY;
 				vma_set_page_prot(vma);
 			}
+			mas_unlock(&mas);
=20
 			inc_tlb_flush_pending(mm);
 			mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
 						0, NULL, mm, 0, -1UL);
 			mmu_notifier_invalidate_range_start(&range);
 		}
-		walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops,
+		walk_page_range(mm, 0, -1, &clear_refs_walk_ops,
 				&cp);
 		if (type =3D=3D CLEAR_REFS_SOFT_DIRTY) {
 			mmu_notifier_invalidate_range_end(&range);
--=20
2.30.2