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Message-ID: <9800e033-0456-b3cc-27e6-cf3d776f6feb@linux.alibaba.com>
Date:   Mon, 28 Mar 2022 10:46:15 +0800
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Subject: Re: [PATCH v6 10/22] erofs: add mode checking helper
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To:     dhowells@redhat.com, linux-cachefs@redhat.com, xiang@kernel.org,
        chao@kernel.org, linux-erofs@lists.ozlabs.org,
        torvalds@linux-foundation.org, gregkh@linuxfoundation.org,
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        joseph.qi@linux.alibaba.com, bo.liu@linux.alibaba.com,
        tao.peng@linux.alibaba.com, gerry@linux.alibaba.com,
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        fannaihao@baidu.com
References: <20220325122223.102958-1-jefflexu@linux.alibaba.com>
 <20220325122223.102958-11-jefflexu@linux.alibaba.com>
 <YkEgoqAKNTf45lJa@B-P7TQMD6M-0146.local>
From:   JeffleXu <jefflexu@linux.alibaba.com>
In-Reply-To: <YkEgoqAKNTf45lJa@B-P7TQMD6M-0146.local>
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On 3/28/22 10:42 AM, Gao Xiang wrote:
> On Fri, Mar 25, 2022 at 08:22:11PM +0800, Jeffle Xu wrote:
>> Until then erofs is exactly blockdev based filesystem. In other using
>> scenarios (e.g. container image), erofs needs to run upon files.
>>
>> This patch set is going to introduces a new nodev mode, in which erofs
>> could be mounted from a bootstrap blob file containing complete erofs
>> image.
>>
>> Add a helper checking which mode erofs works in.
>>
>> Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
>> ---
>>  fs/erofs/internal.h | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
>> index e424293f47a2..1486e2573667 100644
>> --- a/fs/erofs/internal.h
>> +++ b/fs/erofs/internal.h
>> @@ -161,6 +161,11 @@ struct erofs_sb_info {
>>  #define set_opt(opt, option)	((opt)->mount_opt |= EROFS_MOUNT_##option)
>>  #define test_opt(opt, option)	((opt)->mount_opt & EROFS_MOUNT_##option)
>>  
>> +static inline bool erofs_is_nodev_mode(struct super_block *sb)
> 
> I've seen a lot of such
> 
> +		if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) &&
> +		    erofs_is_nodev_mode(sb)) {
> 
> usages in the followup patches, which makes me wonder if the configuration
> can be checked in the helper as well. Also maybe rename it as
> erofs_is_fscache_mode()?
> 

Sure. Will be done in the next version.

-- 
Thanks,
Jeffle