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Message-ID: <e288944b-559c-e184-96c4-370a80cbb9a9@kernel.org>
Date:   Tue, 8 Nov 2022 11:09:29 +0800
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Subject: Re: [PATCH 2/2] erofs: get correct count for unmapped range in
 fscache mode
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To:     Jingbo Xu <jefflexu@linux.alibaba.com>, xiang@kernel.org,
        huyue2@coolpad.com, linux-erofs@lists.ozlabs.org
Cc:     zhujia.zj@bytedance.com, yinxin.x@bytedance.com,
        linux-kernel@vger.kernel.org
References: <20221104054028.52208-1-jefflexu@linux.alibaba.com>
 <20221104054028.52208-3-jefflexu@linux.alibaba.com>
From:   Chao Yu <chao@kernel.org>
In-Reply-To: <20221104054028.52208-3-jefflexu@linux.alibaba.com>
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On 2022/11/4 13:40, Jingbo Xu wrote:
> For unmapped range, the returned map.m_llen is zero, and thus the
> calculated count is unexpected zero.
> 
> Prior to the refactoring introduced by commit 1ae9470c3e14 ("erofs:
> clean up .read_folio() and .readahead() in fscache mode"), only the
> readahead routine suffers from this. With the refactoring of making
> .read_folio() and .readahead() calling one common routine, both
> read_folio and readahead have this issue now.
> 
> Fix this by calculating count separately in unmapped condition.
> 
> Fixes: c665b394b9e8 ("erofs: implement fscache-based data readahead")
> Fixes: 1ae9470c3e14 ("erofs: clean up .read_folio() and .readahead() in fscache mode")
> Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,