[PATCH v2 1/5] proc/task_mmu: remove unnecessary helpers

[Suren Baghdasaryan]

When per-vma locks were behind a config option, a number of helper
functions were needed to simplify the locking code. Now that these
locks are universally available, we can do a little cleanup.
Remove lock_vma_range(), unlock_vma_range(), query_vma_setup(),
query_vma_teardown() helpers.

No functional change intended.

Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
---
 fs/proc/task_mmu.c | 67 ++++++++++++----------------------------------
 1 file changed, 17 insertions(+), 50 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index e671b4fd8ded..2f500d639db5 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -160,25 +160,6 @@ static void unlock_ctx_vma(struct proc_maps_locking_ctx *lock_ctx)
 	}
 }
 
-static inline bool lock_vma_range(struct seq_file *m,
-				  struct proc_maps_locking_ctx *lock_ctx)
-{
-	rcu_read_lock();
-	reset_lock_ctx(lock_ctx);
-
-	return true;
-}
-
-static inline void unlock_vma_range(struct proc_maps_locking_ctx *lock_ctx)
-{
-	if (lock_ctx->mmap_locked) {
-		unlock_ctx_mm(lock_ctx);
-	} else {
-		unlock_ctx_vma(lock_ctx);
-		rcu_read_unlock();
-	}
-}
-
 static struct vm_area_struct *get_next_vma(struct proc_maps_private *priv,
 					   loff_t last_pos)
 {
@@ -286,13 +267,8 @@ static void *m_start(struct seq_file *m, loff_t *ppos)
 		return NULL;
 	}
 
-	if (!lock_vma_range(m, lock_ctx)) {
-		mmput(mm);
-		put_task_struct(priv->task);
-		priv->task = NULL;
-		return ERR_PTR(-EINTR);
-	}
-
+	rcu_read_lock();
+	reset_lock_ctx(lock_ctx);
 	/*
 	 * Reset current position if last_addr was set before
 	 * and it's not a sentinel.
@@ -325,7 +301,12 @@ static void m_stop(struct seq_file *m, void *v)
 		return;
 
 	release_task_mempolicy(priv);
-	unlock_vma_range(&priv->lock_ctx);
+	if (priv->lock_ctx.mmap_locked) {
+		unlock_ctx_mm(&priv->lock_ctx);
+	} else {
+		unlock_ctx_vma(&priv->lock_ctx);
+		rcu_read_unlock();
+	}
 	mmput(mm);
 	put_task_struct(priv->task);
 	priv->task = NULL;
@@ -518,21 +499,6 @@ static int pid_maps_open(struct inode *inode, struct file *file)
 		PROCMAP_QUERY_VMA_FLAGS				\
 )
 
-static int query_vma_setup(struct proc_maps_locking_ctx *lock_ctx)
-{
-	reset_lock_ctx(lock_ctx);
-
-	return 0;
-}
-
-static void query_vma_teardown(struct proc_maps_locking_ctx *lock_ctx)
-{
-	if (lock_ctx->mmap_locked)
-		unlock_ctx_mm(lock_ctx);
-	else
-		unlock_ctx_vma(lock_ctx);
-}
-
 static struct vm_area_struct *query_vma_find_by_addr(struct proc_maps_locking_ctx *lock_ctx,
 						     unsigned long addr)
 {
@@ -653,12 +619,7 @@ static int do_procmap_query(struct mm_struct *mm, void __user *uarg)
 	if (!mm || !mmget_not_zero(mm))
 		return -ESRCH;
 
-	err = query_vma_setup(&lock_ctx);
-	if (err) {
-		mmput(mm);
-		return err;
-	}
-
+	reset_lock_ctx(&lock_ctx);
 	vma = query_matching_vma(&lock_ctx, karg.query_addr, karg.query_flags);
 	if (IS_ERR(vma)) {
 		err = PTR_ERR(vma);
@@ -732,7 +693,10 @@ static int do_procmap_query(struct mm_struct *mm, void __user *uarg)
 		vm_file = get_file(vma->vm_file);
 
 	/* unlock vma or mmap_lock, and put mm_struct before copying data to user */
-	query_vma_teardown(&lock_ctx);
+	if (lock_ctx.mmap_locked)
+		unlock_ctx_mm(&lock_ctx);
+	else
+		unlock_ctx_vma(&lock_ctx);
 	mmput(mm);
 
 	if (karg.build_id_size) {
@@ -773,7 +737,10 @@ static int do_procmap_query(struct mm_struct *mm, void __user *uarg)
 	return 0;
 
 out:
-	query_vma_teardown(&lock_ctx);
+	if (lock_ctx.mmap_locked)
+		unlock_ctx_mm(&lock_ctx);
+	else
+		unlock_ctx_vma(&lock_ctx);
 	mmput(mm);
 out_file:
 	if (vm_file)
-- 
2.55.0.979.g7e5102b832-goog