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

[PATCH] 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 <zhangweiping@didichuxing.com>
---
 mm/backing-dev.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index b5f940c..9117c21 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -885,7 +885,8 @@ 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 create bdi debugfs failed\n", dev_name(dev));
 	set_bit(WB_registered, &bdi->wb.state);
 
 	spin_lock_bh(&bdi_lock);
-- 
2.9.4

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

[Bart Van Assche]

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

[weiping zhang]

2018-01-11 0:10 GMT+08:00 Bart Van Assche <Bart.VanAssche@wdc.com>:
> On Wed, 2018-01-10 at 23:18 +0800, weiping zhang wrote:
>> bdi debugfs dir/file may create fail, add error log here.
>>
>> Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
>> ---
>>  mm/backing-dev.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/mm/backing-dev.c b/mm/backing-dev.c
>> index b5f940c..9117c21 100644
>> --- a/mm/backing-dev.c
>> +++ b/mm/backing-dev.c
>> @@ -885,7 +885,8 @@ 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 create bdi debugfs failed\n", dev_name(dev));
>>       set_bit(WB_registered, &bdi->wb.state);
>>
>>       spin_lock_bh(&bdi_lock);
>
> The indentation of the if-statement is inconsistent. Have you verified this
> patch with checkpatch before submitting it?
>
> Additionally, the error message is hard to understand. Please make it more clear,
> e.g. as follows: "%s: creation of bdi debugfs entries failed.\n".
>
OK, fix them at V2, thanks a lot
> Thanks,
>
> Bart.