Re: [PATCH 1/2] btrfs: improve balance kernel logs

[Nikolay Borisov <nborisov@suse.com>]

On 26.04.2018 11:01, Anand Jain wrote:
> Kernel logs are very important for the forensic investigations of the
> issues in general. This patch adds 'balance:' prefix so that it can be
> easily be searched and uses the block group names instead of its bitmap.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>


Code-wise it looks code. The subject however is somewhat inaccurate, I'd
rather have the subject be explicit about adding the prefix e.h :
"prefix balance related printouts" or "Add balance: prefix to certain
log items".
> ---
>  fs/btrfs/volumes.c | 34 ++++++++++++++++++++--------------
>  1 file changed, 20 insertions(+), 14 deletions(-)
> 
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 14efa98b7183..e688c993197f 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -3805,7 +3805,7 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
>  		    !(bctl->flags & BTRFS_BALANCE_METADATA) ||
>  		    memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
>  			btrfs_err(fs_info,
> -				  "with mixed groups data and metadata balance options must be the same");
> +				  "balance: mixed groups data and metadata options must be the same");
>  			ret = -EINVAL;
>  			goto out;
>  		}
> @@ -3827,23 +3827,26 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
>  		allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
>  			    BTRFS_BLOCK_GROUP_RAID6);
>  	if (validate_convert_profile(&bctl->data, allowed)) {
> +		int index = btrfs_bg_flags_to_raid_index(bctl->data.target);
>  		btrfs_err(fs_info,
> -			  "unable to start balance with target data profile %llu",
> -			  bctl->data.target);
> +			  "balance: invalid convert data profile %s",
> +			  get_raid_name(index));
>  		ret = -EINVAL;
>  		goto out;
>  	}
>  	if (validate_convert_profile(&bctl->meta, allowed)) {
> +		int index = btrfs_bg_flags_to_raid_index(bctl->meta.target);
>  		btrfs_err(fs_info,
> -			  "unable to start balance with target metadata profile %llu",
> -			  bctl->meta.target);
> +			  "balance: invalid convert metadata profile %s",
> +			  get_raid_name(index));
>  		ret = -EINVAL;
>  		goto out;
>  	}
>  	if (validate_convert_profile(&bctl->sys, allowed)) {
> +		int index = btrfs_bg_flags_to_raid_index(bctl->sys.target);
>  		btrfs_err(fs_info,
> -			  "unable to start balance with target system profile %llu",
> -			  bctl->sys.target);
> +			  "balance: invalid convert system profile %s",
> +			  get_raid_name(index));
>  		ret = -EINVAL;
>  		goto out;
>  	}
> @@ -3864,10 +3867,10 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
>  		     !(bctl->meta.target & allowed))) {
>  			if (bctl->flags & BTRFS_BALANCE_FORCE) {
>  				btrfs_info(fs_info,
> -					   "force reducing metadata integrity");
> +					   "balance: force reducing metadata integrity");
>  			} else {
>  				btrfs_err(fs_info,
> -					  "balance will reduce metadata integrity, use force if you want this");
> +					  "balance: reduces metadata integrity, use force if you want this");
>  				ret = -EINVAL;
>  				goto out;
>  			}
> @@ -3881,9 +3884,11 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
>  		bctl->data.target : fs_info->avail_data_alloc_bits;
>  	if (btrfs_get_num_tolerated_disk_barrier_failures(meta_target) <
>  		btrfs_get_num_tolerated_disk_barrier_failures(data_target)) {
> +		int meta_index = btrfs_bg_flags_to_raid_index(meta_target);
> +		int data_index = btrfs_bg_flags_to_raid_index(data_target);
>  		btrfs_warn(fs_info,
> -			   "metadata profile 0x%llx has lower redundancy than data profile 0x%llx",
> -			   meta_target, data_target);
> +			   "balance: metadata profile %s has lower redundancy than data profile %s",
> +			   get_raid_name(meta_index), get_raid_name(data_index));
>  	}
>  
>  	ret = insert_balance_item(fs_info, bctl);
> @@ -3943,7 +3948,7 @@ static int balance_kthread(void *data)
>  
>  	mutex_lock(&fs_info->balance_mutex);
>  	if (fs_info->balance_ctl) {
> -		btrfs_info(fs_info, "continuing balance");
> +		btrfs_info(fs_info, "balance: resuming");
>  		ret = btrfs_balance(fs_info->balance_ctl, NULL);
>  	}
>  	mutex_unlock(&fs_info->balance_mutex);
> @@ -3963,7 +3968,7 @@ int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
>  	mutex_unlock(&fs_info->balance_mutex);
>  
>  	if (btrfs_test_opt(fs_info, SKIP_BALANCE)) {
> -		btrfs_info(fs_info, "force skipping balance");
> +		btrfs_info(fs_info, "balance: resume skipped");
>  		return 0;
>  	}
>  
> @@ -4032,7 +4037,7 @@ int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
>  	 */
>  	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
>  		btrfs_warn(fs_info,
> -	"cannot set exclusive op status to balance, resume manually");
> +	"balance: cannot set exclusive op status, resume manually");
>  
>  	mutex_lock(&fs_info->balance_mutex);
>  	BUG_ON(fs_info->balance_ctl);
> @@ -4111,6 +4116,7 @@ int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
>  		if (fs_info->balance_ctl) {
>  			reset_balance_state(fs_info);
>  			clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
> +			btrfs_info(fs_info, "balance: canceled");
>  		}
>  	}
>  
>