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From:   OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To:     "Darrick J. Wong" <darrick.wong@oracle.com>
Cc:     Hou Tao <houtao1@huawei.com>, linux-fsdevel@vger.kernel.org,
        viro@zeniv.linux.org.uk, jack@suse.cz, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fat: issue flush after the writeback of FAT
References: <20190409030158.136316-1-houtao1@huawei.com>
        <20190409034100.GF1177@magnolia>
Date:   Tue, 09 Apr 2019 14:22:31 +0900
In-Reply-To: <20190409034100.GF1177@magnolia> (Darrick J. Wong's message of
        "Mon, 8 Apr 2019 20:41:00 -0700")
Message-ID: <87a7gzbvmw.fsf@mail.parknet.co.jp>
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"Darrick J. Wong" <darrick.wong@oracle.com> writes:

>> +	err = __generic_file_fsync(filp, start, end, datasync);
>> +	if (err)
>> +		return err;
>>  
>> -	res = generic_file_fsync(filp, start, end, datasync);
>>  	err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
>
> Huh.  I would've thought that flushing the FAT would also be required
> at the end of a WB_SYNC_ALL (aka data integrity) writepages call?

In fatfs implement, FAT area is flushed by sync_mapping_buffers(fat_inode). 
(FAT buffer is dirtied only by using bh->b_assoc_map to fat_inode)

Thanks.
-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>