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Subject: Re: [PATCH] bcache: fix cache miss's issue
To:     Qiang Bai <chiang.bai@gmail.com>
Cc:     linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org,
        kent.overstreet@gmail.com
References: <20210627071817.24296-1-chiang.bai@gmail.com>
From:   Coly Li <colyli@suse.de>
Message-ID: <b7be3c15-aae6-3952-26bc-1ee35e661327@suse.de>
Date:   Tue, 29 Jun 2021 00:05:09 +0800
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On 6/27/21 3:18 PM, Qiang Bai wrote:
> when cache miss's IO was done, it needs to continue the left part of IO,
> not return -EINTR. -EINTR will stop the whole btree recurse.
>
> Signed-off-by: Qiang Bai <chiang.bai@gmail.com>

NACK.  The commit log should explain how the fixing issue happens in
detail, and why your method fixes it.

Thanks.

Coly Li

> ---
>  drivers/md/bcache/request.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
> index 29c231758293..b6ff101d2611 100644
> --- a/drivers/md/bcache/request.c
> +++ b/drivers/md/bcache/request.c
> @@ -914,7 +914,7 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
>  	miss = bio_next_split(bio, sectors, GFP_NOIO, &s->d->bio_split);
>  
>  	/* btree_search_recurse()'s btree iterator is no good anymore */
> -	ret = miss == bio ? MAP_DONE : -EINTR;
> +	ret = miss == bio ? MAP_DONE : MAP_CONTINUE;
>  
>  	cache_bio = bio_alloc_bioset(GFP_NOWAIT,
>  			DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),