backing-dev: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

And as the return value does not matter at all, no need to save the
dentry in struct backing_dev_info, so delete it.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: linux-mm@kvack.org
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 5 insertions, 20 deletions

diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index 07e02d6df5ad..6a1a8a314d85 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h
@@ -203,7 +203,6 @@ struct backing_dev_info {
 
 #ifdef CONFIG_DEBUG_FS
         struct dentry *debug_dir;
-        struct dentry *debug_stats;
 #endif
 };
 
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 909dae445ea7..e8e89158adec 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -103,39 +103,25 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v)
 }
 DEFINE_SHOW_ATTRIBUTE(bdi_debug_stats);
 
-static int bdi_debug_register(struct backing_dev_info *bdi, const char *name)
+static void bdi_debug_register(struct backing_dev_info *bdi, const char *name)
 {
-        if (!bdi_debug_root)
-                return -ENOMEM;
-
         bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root);
-        if (!bdi->debug_dir)
-                return -ENOMEM;
-
-        bdi->debug_stats = debugfs_create_file("stats", 0444, bdi->debug_dir,
-                                               bdi, &bdi_debug_stats_fops);
-        if (!bdi->debug_stats) {
-                debugfs_remove(bdi->debug_dir);
-                bdi->debug_dir = NULL;
-                return -ENOMEM;
-        }
 
-        return 0;
+        debugfs_create_file("stats", 0444, bdi->debug_dir, bdi,
+                            &bdi_debug_stats_fops);
 }
 
 static void bdi_debug_unregister(struct backing_dev_info *bdi)
 {
-        debugfs_remove(bdi->debug_stats);
-        debugfs_remove(bdi->debug_dir);
+        debugfs_remove_recursive(bdi->debug_dir);
 }
 #else
 static inline void bdi_debug_init(void)
 {
 }
-static inline int bdi_debug_register(struct backing_dev_info *bdi,
+static inline void bdi_debug_register(struct backing_dev_info *bdi,
                                       const char *name)
 {
-        return 0;
 }
 static inline void bdi_debug_unregister(struct backing_dev_info *bdi)
 {