# Re: \[PATCH 2/8\] imsm: write bad block log on metadata sync

- From: Jes Sorensen \<hidden\>
- Date: 2016-11-16 14:47:52 
- List: linux-raid
- Page: https://ratatoskr.run/linux-raid/2016/11/6633456
- Thread: https://ratatoskr.run/linux-raid/2016/11/6633456/t.md

```text
Tomasz Majchrzak [ref] writes:
> Pre-allocate memory for largest possible bad block sectionwhen monitor
> is being opened to avoid a need for memory allocation on metadata sync.
>
> If memory for a structure has been allocated in mpb buffer but it hasn't
> been used yet, it will be taken by next buffer grow, leading to
> insufficient memory on metadata flush. Start tracking such memory and
> take it into calculation when growing a buffer. Also assert has been
> added to debug mode to warn when more metadata has been written than
> memory allocated.
>
> Signed-off-by: Tomasz Majchrzak <redacted>
> ---
>  super-intel.c | 49 +++++++++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 45 insertions(+), 4 deletions(-)
>
> diff --git a/super-intel.c b/super-intel.c
> index 5d6d534..0591c55 100644
> --- a/super-intel.c
> +++ b/super-intel.c

[snip]

> @@ -8854,6 +8886,9 @@ static void imsm_process_update(struct supertype *st,
>  		}
>  		break;
>  	}
> +	case update_prealloc_badblocks_mem: {
> +		break;
> +	}
>  	default:
>  		pr_err("error: unsuported process update type:(type: %d)\n",	type);
>  	}

Please don't include those awful brackets if you don't need them here.

> @@ -9094,6 +9129,11 @@ static int imsm_prepare_update(struct supertype *st,
>  	case update_add_remove_disk:
>  		/* no update->len needed */
>  		break;
> +	case update_prealloc_badblocks_mem: {
> +		super->extra_space += sizeof(struct bbm_log) -
> +			get_imsm_bbm_log_size(super->bbm_log);
> +		break;
> +	}
>  	default:
>  		return 0;
>  	}

Same here

Thanks,
Jes
```