From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 23 Aug 2025 06:06:57 +0000 (-0400)
Subject: fs/namespace.c: allow to drop vfsmount references via __free(mntput)
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=547af12dcd43851a4894ffc3c60e381ab9f0f5e7;p=users%2Fhch%2Fmisc.git

fs/namespace.c: allow to drop vfsmount references via __free(mntput)

Note that just as path_put, it should never be done in scope of
namespace_sem, be it shared or exclusive.

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 fcea65587ff9..767ab751ee2a 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -88,6 +88,8 @@ DEFINE_LOCK_GUARD_0(namespace_excl, namespace_lock(), namespace_unlock())
 DEFINE_LOCK_GUARD_0(namespace_shared, down_read(&namespace_sem),
 				      up_read(&namespace_sem))
 
+DEFINE_FREE(mntput, struct vfsmount *, if (!IS_ERR(_T)) mntput(_T))
+
 #ifdef CONFIG_FSNOTIFY
 LIST_HEAD(notify_list); /* protected by namespace_sem */
 #endif