Re: [PATCH 09/14] bcache: use bucket index to set GC_MARK_METADATA for journal buckets in bch_btree_gc_finish()

[Hannes Reinecke <hare@suse.de>]

On 6/15/21 7:49 AM, Coly Li wrote:
> Currently the meta data bucket locations on cache device are reserved
> after the meta data stored on NVDIMM pages, for the meta data layout
> consistentcy temporarily. So these buckets are still marked as meta data
> by SET_GC_MARK() in bch_btree_gc_finish().
> 
> When BCH_FEATURE_INCOMPAT_NVDIMM_META is set, the sb.d[] stores linear
> address of NVDIMM pages and not bucket index anymore. Therefore we
> should avoid to find bucket index from sb.d[], and directly use bucket
> index from ca->sb.first_bucket to (ca->sb.first_bucket +
> ca->sb.njournal_bucketsi) for setting the gc mark of journal bucket.
> 
> Signed-off-by: Coly Li <colyli@suse.de>
> Cc: Jianpeng Ma <jianpeng.ma@intel.com>
> Cc: Qiaowei Ren <qiaowei.ren@intel.com>
> ---
>  drivers/md/bcache/btree.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
> index 183a58c89377..e0d7135669ca 100644
> --- a/drivers/md/bcache/btree.c
> +++ b/drivers/md/bcache/btree.c
> @@ -1761,8 +1761,10 @@ static void bch_btree_gc_finish(struct cache_set *c)
>  	ca = c->cache;
>  	ca->invalidate_needs_gc = 0;
>  
> -	for (k = ca->sb.d; k < ca->sb.d + ca->sb.keys; k++)
> -		SET_GC_MARK(ca->buckets + *k, GC_MARK_METADATA);
> +	/* Range [first_bucket, first_bucket + keys) is for journal buckets */
> +	for (i = ca->sb.first_bucket;
> +	     i < ca->sb.first_bucket + ca->sb.njournal_buckets; i++)
> +		SET_GC_MARK(ca->buckets + i, GC_MARK_METADATA);
>  
>  	for (k = ca->prio_buckets;
>  	     k < ca->prio_buckets + prio_buckets(ca) * 2; k++)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		           Kernel Storage Architect
hare@suse.de			                  +49 911 74053 688
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