make securityfs_remove() remove the entire subtree

... and fix the mount leak when anything's mounted there.
securityfs_recursive_remove becomes an alias for securityfs_remove -
we'll probably need to remove it in a cycle or two.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Author: Al Viro

include/linux/security.h

@@ -2211,7 +2211,6 @@ struct dentry *securityfs_create_symlink(const char *name,
 					 const char *target,
 					 const struct inode_operations *iops);
 extern void securityfs_remove(struct dentry *dentry);
-extern void securityfs_recursive_remove(struct dentry *dentry);
 
 #else /* CONFIG_SECURITYFS */
 
@@ -2243,6 +2242,8 @@ static inline void securityfs_remove(struct dentry *dentry)
 
 #endif
 
+#define securityfs_recursive_remove securityfs_remove
+
 #ifdef CONFIG_BPF_SYSCALL
 union bpf_attr;
 struct bpf_map;

security/inode.c

@@ -281,6 +281,12 @@ struct dentry *securityfs_create_symlink(const char *name,
 }
 EXPORT_SYMBOL_GPL(securityfs_create_symlink);
 
+static void remove_one(struct dentry *victim)
+{
+	if (victim->d_parent == victim->d_sb->s_root)
+		simple_release_fs(&mount, &mount_count);
+}
+
 /**
  * securityfs_remove - removes a file or directory from the securityfs filesystem
  *
@@ -293,44 +299,11 @@ EXPORT_SYMBOL_GPL(securityfs_create_symlink);
  * This function is required to be called in order for the file to be
  * removed. No automatic cleanup of files will happen when a module is
  * removed; you are responsible here.
- */
-void securityfs_remove(struct dentry *dentry)
-{
-	struct inode *dir;
-
-	if (IS_ERR_OR_NULL(dentry))
-		return;
-
-	dir = d_inode(dentry->d_parent);
-	inode_lock(dir);
-	if (simple_positive(dentry)) {
-		if (d_is_dir(dentry))
-			simple_rmdir(dir, dentry);
-		else
-			simple_unlink(dir, dentry);
-	}
-	inode_unlock(dir);
-	if (dir == dir->i_sb->s_root->d_inode)
-		simple_release_fs(&mount, &mount_count);
-}
-EXPORT_SYMBOL_GPL(securityfs_remove);
-
-static void remove_one(struct dentry *victim)
-{
-	if (victim->d_parent == victim->d_sb->s_root)
-		simple_release_fs(&mount, &mount_count);
-}
-
-/**
- * securityfs_recursive_remove - recursively removes a file or directory
- *
- * @dentry: a pointer to a the dentry of the file or directory to be removed.
  *
- * This function recursively removes a file or directory in securityfs that was
- * previously created with a call to another securityfs function (like
- * securityfs_create_file() or variants thereof.)
+ * AV: when applied to directory it will take all children out; no need to call
+ * it for descendents if ancestor is getting killed.
  */
-void securityfs_recursive_remove(struct dentry *dentry)
+void securityfs_remove(struct dentry *dentry)
 {
 	if (IS_ERR_OR_NULL(dentry))
 		return;
@@ -339,7 +312,7 @@ void securityfs_recursive_remove(struct dentry *dentry)
 	simple_recursive_removal(dentry, remove_one);
 	simple_release_fs(&mount, &mount_count);
 }
-EXPORT_SYMBOL_GPL(securityfs_recursive_remove);
+EXPORT_SYMBOL_GPL(securityfs_remove);
 
 #ifdef CONFIG_SECURITY
 static struct dentry *lsm_dentry;