[PATCH v3 10/65] mnt_already_visible(): use guards

[Al Viro <viro@xxxxxxxxxxxxxxxxxx>]

clean fit; namespace_shared due to iterating through ns->mounts.

Reviewed-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
 fs/namespace.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/fs/namespace.c b/fs/namespace.c
index 86a86be2b0ef..a5d37b97088f 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -6232,9 +6232,8 @@ static bool mnt_already_visible(struct mnt_namespace *ns,
 {
 	int new_flags = *new_mnt_flags;
 	struct mount *mnt, *n;
-	bool visible = false;
 
-	down_read(&namespace_sem);
+	guard(namespace_shared)();
 	rbtree_postorder_for_each_entry_safe(mnt, n, &ns->mounts, mnt_node) {
 		struct mount *child;
 		int mnt_flags;
@@ -6281,13 +6280,10 @@ static bool mnt_already_visible(struct mnt_namespace *ns,
 		/* Preserve the locked attributes */
 		*new_mnt_flags |= mnt_flags & (MNT_LOCK_READONLY | \
 					       MNT_LOCK_ATIME);
-		visible = true;
-		goto found;
+		return true;
 	next:	;
 	}
-found:
-	up_read(&namespace_sem);
-	return visible;
+	return false;
 }
 
 static bool mount_too_revealing(const struct super_block *sb, int *new_mnt_flags)
-- 
2.47.2