kernfs: remove KERNFS_STATIC_NAME

When a new kernfs node is created, KERNFS_STATIC_NAME is used to avoid
making a separate copy of its name.  It's currently only used for sysfs
attributes whose filenames are required to stay accessible and unchanged.
There are rare exceptions where these names are allocated and formatted
dynamically but for the vast majority of cases they're consts in the
rodata section.

Now that kernfs is converted to use kstrdup_const() and kfree_const(),
there's little point in keeping KERNFS_STATIC_NAME around.  Remove it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 12 insertions, 23 deletions

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 35e40879860a..6acc9648f986 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -411,8 +411,9 @@ void kernfs_put(struct kernfs_node *kn)
 
 	if (kernfs_type(kn) == KERNFS_LINK)
 		kernfs_put(kn->symlink.target_kn);
-	if (!(kn->flags & KERNFS_STATIC_NAME))
-		kfree_const(kn->name);
+
+	kfree_const(kn->name);
+
 	if (kn->iattr) {
 		if (kn->iattr->ia_secdata)
 			security_release_secctx(kn->iattr->ia_secdata,
@@ -506,15 +507,12 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
 					     const char *name, umode_t mode,
 					     unsigned flags)
 {
-	const char *dup_name = NULL;
 	struct kernfs_node *kn;
 	int ret;
 
-	if (!(flags & KERNFS_STATIC_NAME)) {
-		name = dup_name = kstrdup_const(name, GFP_KERNEL);
-		if (!name)
-			return NULL;
-	}
+	name = kstrdup_const(name, GFP_KERNEL);
+	if (!name)
+		return NULL;
 
 	kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL);
 	if (!kn)
@@ -538,7 +536,7 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
  err_out2:
 	kmem_cache_free(kernfs_node_cache, kn);
  err_out1:
-	kfree_const(dup_name);
+	kfree_const(name);
 	return NULL;
 }
 
@@ -1285,9 +1283,7 @@ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
 
 	kn->ns = new_ns;
 	if (new_name) {
-		if (!(kn->flags & KERNFS_STATIC_NAME))
-			old_name = kn->name;
-		kn->flags &= ~KERNFS_STATIC_NAME;
+		old_name = kn->name;
 		kn->name = new_name;
 	}
 
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index ddc9f9612f16..b684e8a132e6 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -901,7 +901,6 @@ const struct file_operations kernfs_file_fops = {
  * @ops: kernfs operations for the file
  * @priv: private data for the file
  * @ns: optional namespace tag of the file
- * @name_is_static: don't copy file name
  * @key: lockdep key for the file's active_ref, %NULL to disable lockdep
  *
  * Returns the created node on success, ERR_PTR() value on error.
@@ -911,7 +910,6 @@ struct kernfs_node *__kernfs_create_file(struct kernfs_node *parent,
 					 umode_t mode, loff_t size,
 					 const struct kernfs_ops *ops,
 					 void *priv, const void *ns,
-					 bool name_is_static,
 					 struct lock_class_key *key)
 {
 	struct kernfs_node *kn;
@@ -919,8 +917,6 @@ struct kernfs_node *__kernfs_create_file(struct kernfs_node *parent,
 	int rc;
 
 	flags = KERNFS_FILE;
-	if (name_is_static)
-		flags |= KERNFS_STATIC_NAME;
 
 	kn = kernfs_new_node(parent, name, (mode & S_IALLUGO) | S_IFREG, flags);
 	if (!kn)
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index dfe928a9540f..7c2867b44141 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -295,7 +295,7 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent,
 		key = attr->key ?: (struct lock_class_key *)&attr->skey;
 #endif
 	kn = __kernfs_create_file(parent, attr->name, mode & 0777, size, ops,
-				  (void *)attr, ns, true, key);
+				  (void *)attr, ns, key);
 	if (IS_ERR(kn)) {
 		if (PTR_ERR(kn) == -EEXIST)
 			sysfs_warn_dup(parent, attr->name);
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index d4e01b358341..71ecdab1671b 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -43,7 +43,6 @@ enum kernfs_node_flag {
 	KERNFS_HAS_SEQ_SHOW	= 0x0040,
 	KERNFS_HAS_MMAP		= 0x0080,
 	KERNFS_LOCKDEP		= 0x0100,
-	KERNFS_STATIC_NAME	= 0x0200,
 	KERNFS_SUICIDAL		= 0x0400,
 	KERNFS_SUICIDED		= 0x0800,
 };
@@ -291,7 +290,6 @@ struct kernfs_node *__kernfs_create_file(struct kernfs_node *parent,
 					 umode_t mode, loff_t size,
 					 const struct kernfs_ops *ops,
 					 void *priv, const void *ns,
-					 bool name_is_static,
 					 struct lock_class_key *key);
 struct kernfs_node *kernfs_create_link(struct kernfs_node *parent,
 				       const char *name,
@@ -369,8 +367,7 @@ kernfs_create_dir_ns(struct kernfs_node *parent, const char *name,
 static inline struct kernfs_node *
 __kernfs_create_file(struct kernfs_node *parent, const char *name,
 		     umode_t mode, loff_t size, const struct kernfs_ops *ops,
-		     void *priv, const void *ns, bool name_is_static,
-		     struct lock_class_key *key)
+		     void *priv, const void *ns, struct lock_class_key *key)
 { return ERR_PTR(-ENOSYS); }
 
 static inline struct kernfs_node *
@@ -439,7 +436,7 @@ kernfs_create_file_ns(struct kernfs_node *parent, const char *name,
 	key = (struct lock_class_key *)&ops->lockdep_key;
 #endif
 	return __kernfs_create_file(parent, name, mode, size, ops, priv, ns,
-				    false, key);
+				    key);
 }
 
 static inline struct kernfs_node *
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index d5f6ec251fb2..29a7b2cc593e 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3077,7 +3077,7 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cftype *cft)
 #endif
 	kn = __kernfs_create_file(cgrp->kn, cgroup_file_name(cgrp, cft, name),
 				  cgroup_file_mode(cft), 0, cft->kf_ops, cft,
-				  NULL, false, key);
+				  NULL, key);
 	if (IS_ERR(kn))
 		return PTR_ERR(kn);