From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 21 Aug 2025 00:12:47 +0000 (-0400)
Subject: __detach_mounts(): use guards
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=902e9904672bedcb25c6740d5c1d09e17de807eb;p=users%2Fhch%2Fmisc.git

__detach_mounts(): use guards

Clean fit for guards use; guards can't be weaker due to umount_tree() calls.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/namespace.c b/fs/namespace.c
index 767ab751ee2a..1ae1ab8815c9 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2032,10 +2032,11 @@ void __detach_mounts(struct dentry *dentry)
 	struct pinned_mountpoint mp = {};
 	struct mount *mnt;
 
-	namespace_lock();
-	lock_mount_hash();
+	guard(namespace_excl)();
+	guard(mount_writer)();
+
 	if (!lookup_mountpoint(dentry, &mp))
-		goto out_unlock;
+		return;
 
 	event++;
 	while (mp.node.next) {
@@ -2047,9 +2048,6 @@ void __detach_mounts(struct dentry *dentry)
 		else umount_tree(mnt, UMOUNT_CONNECTED);
 	}
 	unpin_mountpoint(&mp);
-out_unlock:
-	unlock_mount_hash();
-	namespace_unlock();
 }
 
 /*