Re: [PATCH 1/1] btrfs: add kernel scrub log messages

[Anand Jain <anand.jain@oracle.com>]

On 01/03/2019 01:20 AM, David Sterba wrote:
> On Mon, Dec 17, 2018 at 11:15:12AM +0800, Anand Jain wrote:
>> scrub kernel messages helps debug and audit, add them to the log.
>>
>> Signed-off-by: Anand Jain <anand.jain@oracle.com>
>> ---
>>   fs/btrfs/scrub.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
>> index 902819d3cf41..d7a92521019e 100644
>> --- a/fs/btrfs/scrub.c
>> +++ b/fs/btrfs/scrub.c
>> @@ -3876,6 +3876,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
>>   	mutex_unlock(&fs_info->scrub_lock);
>>   
>>   	if (!is_dev_replace) {
>> +		btrfs_info(fs_info, "scrub: devid %llu %s", devid, "started");
my bad, will fix.
> 
> Why do you print a fixed and known string using %s?
> 
>>   		/*
>>   		 * by holding device list mutex, we can
>>   		 * kick off writing super in log tree sync.
>> @@ -3897,6 +3898,10 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
>>   	if (progress)
>>   		memcpy(progress, &sctx->stat, sizeof(*progress));
>>   
>> +	if (!is_dev_replace)
>> +		btrfs_info(fs_info, "scrub: devid %llu %s:%d",
>> +			   devid, ret ? "not finished":"finished", ret);
> 
> Spaces around binary operators please: ret ? "not finished" : "finished"

added in v2.
> What's the reason to print the error code here? It is returned from the
> ioctl.

It does not get logged. Help offline debugging.