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Subject: Re: [PATCH] erofs: derive atime instead of leaving it empty
To:     Gao Xiang <hsiangkao@aol.com>, <linux-erofs@lists.ozlabs.org>,
        Chao Yu <chao@kernel.org>
CC:     LKML <linux-kernel@vger.kernel.org>,
        Gao Xiang <hsiangkao@redhat.com>, nl6720 <nl6720@gmail.com>,
        stable <stable@vger.kernel.org>
References: <20201031195102.21221-1-hsiangkao.ref@aol.com>
 <20201031195102.21221-1-hsiangkao@aol.com>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <bf522e01-97c6-e9b7-6f28-f88b64233aaf@huawei.com>
Date:   Wed, 4 Nov 2020 08:57:07 +0800
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On 2020/11/1 3:51, Gao Xiang wrote:
> From: Gao Xiang <hsiangkao@redhat.com>
> 
> EROFS has _only one_ ondisk timestamp (ctime is currently
> documented and recorded, we might also record mtime instead
> with a new compat feature if needed) for each extended inode
> since EROFS isn't mainly for archival purposes so no need to
> keep all timestamps on disk especially for Android scenarios
> due to security concerns. Also, romfs/cramfs don't have their
> own on-disk timestamp, and squashfs only records mtime instead.
> 
> Let's also derive access time from ondisk timestamp rather than
> leaving it empty, and if mtime/atime for each file are really
> needed for specific scenarios as well, we can also use xattrs
> to record them then.
> 
> Reported-by: nl6720 <nl6720@gmail.com>
> [ Gao Xiang: It'd be better to backport for user-friendly concern. ]
> Fixes: 431339ba9042 ("staging: erofs: add inode operations")
> Cc: stable <stable@vger.kernel.org> # 4.19+
> Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

Looks good to me. :)

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,