[patch 096/166] proc: inline vma_stop into m_stop

Andrew Morton
2020-04-07T03:09:10Z

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: proc: inline vma_stop into m_stop

Instead of calling vma_stop() from m_start() and m_next(), do its work
in m_stop().

Link: http://lkml.kernel.org/r/20200317193201.9924-1-adobriyan@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

fs/proc/task_mmu.c | 34 +++++++++++++++-------------------
1 file changed, 15 insertions(+), 19 deletions(-)

--- a/fs/proc/task_mmu.c~proc-inline-vma_stop-into-m_stop
+++ a/fs/proc/task_mmu.c
@@ -123,15 +123,6 @@ static void release_task_mempolicy(struc
}
#endif

-static void vma_stop(struct proc_maps_private *priv)
-{
- struct mm_struct *mm = priv->mm;
-
- release_task_mempolicy(priv);
- up_read(&mm->mmap_sem);
- mmput(mm);
-}
-
static struct vm_area_struct *
m_next_vma(struct proc_maps_private *priv, struct vm_area_struct *vma)
{
@@ -163,11 +154,16 @@ static void *m_start(struct seq_file *m,
return ERR_PTR(-ESRCH);

mm = priv->mm;
- if (!mm || !mmget_not_zero(mm))
+ if (!mm || !mmget_not_zero(mm)) {
+ put_task_struct(priv->task);
+ priv->task = NULL;
return NULL;
+ }

if (down_read_killable(&mm->mmap_sem)) {
mmput(mm);
+ put_task_struct(priv->task);
+ priv->task = NULL;
return ERR_PTR(-EINTR);
}

@@ -195,7 +191,6 @@ static void *m_start(struct seq_file *m,
if (pos == mm->map_count && priv->tail_vma)
return priv->tail_vma;

- vma_stop(priv);
return NULL;
}

@@ -206,21 +201,22 @@ static void *m_next(struct seq_file *m,

(*pos)++;
next = m_next_vma(priv, v);
- if (!next)
- vma_stop(priv);
return next;
}

static void m_stop(struct seq_file *m, void *v)
{
struct proc_maps_private *priv = m->private;
+ struct mm_struct *mm = priv->mm;

- if (!IS_ERR_OR_NULL(v))
- vma_stop(priv);
- if (priv->task) {
- put_task_struct(priv->task);
- priv->task = NULL;
- }
+ if (!priv->task)
+ return;
+
+ release_task_mempolicy(priv);
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ put_task_struct(priv->task);
+ priv->task = NULL;
}

static int proc_maps_open(struct inode *inode, struct file *file,
_