linux-kernel - [RFC PATCH v3 16/59] fs: hide names_cache behind runtime const machinery

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Message-ID: <20251216035518.4037331-17-viro@zeniv.linux.org.uk>
Date: Tue, 16 Dec 2025 03:54:35 +0000
From: Al Viro <viro@...iv.linux.org.uk>
To: linux-fsdevel@...r.kernel.org
Cc: torvalds@...ux-foundation.org,
	brauner@...nel.org,
	jack@...e.cz,
	mjguzik@...il.com,
	paul@...l-moore.com,
	axboe@...nel.dk,
	audit@...r.kernel.org,
	io-uring@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [RFC PATCH v3 16/59] fs: hide names_cache behind runtime const machinery

From: Mateusz Guzik <mjguzik@...il.com>

s/names_cachep/names_cache/ for consistency with dentry cache.

Signed-off-by: Mateusz Guzik <mjguzik@...il.com>
Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
 fs/namei.c                        | 16 ++++++++++------
 include/asm-generic/vmlinux.lds.h |  3 ++-
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 9053aeee05d5..15e14802cabb 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -41,6 +41,8 @@
 #include <linux/init_task.h>
 #include <linux/uaccess.h>
 
+#include <asm/runtime-const.h>
+
 #include "internal.h"
 #include "mount.h"
 
@@ -124,23 +126,25 @@
  */
 
 /* SLAB cache for struct filename instances */
-static struct kmem_cache *names_cachep __ro_after_init;
+static struct kmem_cache *__names_cache __ro_after_init;
+#define names_cache	runtime_const_ptr(__names_cache)
 
 void __init filename_init(void)
 {
-	names_cachep = kmem_cache_create_usercopy("names_cache", sizeof(struct filename), 0,
-			SLAB_HWCACHE_ALIGN|SLAB_PANIC, offsetof(struct filename, iname),
-						EMBEDDED_NAME_MAX, NULL);
+	__names_cache = kmem_cache_create_usercopy("names_cache", sizeof(struct filename), 0,
+			 SLAB_HWCACHE_ALIGN|SLAB_PANIC, offsetof(struct filename, iname),
+			 EMBEDDED_NAME_MAX, NULL);
+	runtime_const_init(ptr, __names_cache);
 }
 
 static inline struct filename *alloc_filename(void)
 {
-	return kmem_cache_alloc(names_cachep, GFP_KERNEL);
+	return kmem_cache_alloc(names_cache, GFP_KERNEL);
 }
 
 static inline void free_filename(struct filename *p)
 {
-	kmem_cache_free(names_cachep, p);
+	kmem_cache_free(names_cache, p);
 }
 
 static inline void initname(struct filename *name)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 8ca130af301f..eeb070f330bd 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -972,7 +972,8 @@
 #define RUNTIME_CONST_VARIABLES						\
 		RUNTIME_CONST(shift, d_hash_shift)			\
 		RUNTIME_CONST(ptr, dentry_hashtable)			\
-		RUNTIME_CONST(ptr, __dentry_cache)
+		RUNTIME_CONST(ptr, __dentry_cache)			\
+		RUNTIME_CONST(ptr, __names_cache)
 
 /* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */
 #define KUNIT_TABLE()							\
-- 
2.47.3