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References: <20230720091436.399691-1-yunlong.xing@unisoc.com>
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From:   Miklos Szeredi <miklos@szeredi.hu>
Date:   Tue, 1 Aug 2023 19:43:05 +0200
Message-ID: <CAJfpeguygW3JY5L5d+87+V538hAWu2tL9Yksg5p-QMP3ppv13w@mail.gmail.com>
Subject: Re: [PATCH V3] ovl: fix mount fail because the upper doesn't have space
To:     Yunlong Xing <yunlong.xing@unisoc.com>
Cc:     amir73il@gmail.com, linux-unionfs@vger.kernel.org,
        linux-kernel@vger.kernel.org, zhiguo.niu@unisoc.com,
        hongyu.jin@unisoc.com, yunlongxing23@gmail.com
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On Thu, 20 Jul 2023 at 11:15, Yunlong Xing <yunlong.xing@unisoc.com> wrote:
>
> The current ovlfs mount flow:
>
> ovl_fill_super
>  |_ovl_get_workdir
>     |_ovl_make_workdir
>        |_ovl_check_rename_whiteout
>
> In ovl_check_rename_whiteout(), a new file is attempted to create.But if
> the upper doesn't have space to do this, it will return error -ENOSPC,
> causing the mount fail. It means that if the upper is full, the overlayfs
> cannot be mounted. It is not reasonable, so this patch will omit this error
> and continue mount flow.

Wouldn't mounting without upper (two or more lower layers) work in this case?

Thanks,
Miklos