[PATCH v2] bdi: show error log when fail to create bdi debugfs entry

[weiping zhang]

bdi debugfs dir/file may create fail, add error log here.

Signed-off-by: weiping zhang <zhangweip...@didichuxing.com>
---
V1->V2:
fix indentation and make log message more clear

 mm/backing-dev.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index b5f940c..0a49665 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -885,7 +885,9 @@ int bdi_register_va(struct backing_dev_info *bdi, const 
char *fmt, va_list args)
        cgwb_bdi_register(bdi);
        bdi->dev = dev;
 
-       bdi_debug_register(bdi, dev_name(dev));
+       if (bdi_debug_register(bdi, dev_name(dev)))
+               pr_warn("blkdev %s: creation of bdi debugfs entries failed.\n",
+                       dev_name(dev));
        set_bit(WB_registered, &bdi->wb.state);
 
        spin_lock_bh(&bdi_lock);
-- 
2.9.4