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Date:   Tue, 18 Feb 2020 12:04:42 -0500
From:   "Theodore Y. Ts'o" <tytso@mit.edu>
To:     "zhangyi (F)" <yi.zhang@huawei.com>
Cc:     Jan Kara <jack@suse.cz>, linux-ext4@vger.kernel.org,
        luoshijie1@huawei.com, zhangxiaoxu5@huawei.com
Subject: Re: [PATCH v3 2/2] jbd2: do not clear the BH_Mapped flag when
 forgetting a metadata buffer
Message-ID: <20200218170442.GC147128@mit.edu>
References: <20200213063821.30455-1-yi.zhang@huawei.com>
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 <20200217093645.GC12032@quack2.suse.cz>
 <dcdd498d-68b4-360c-f0f1-3ee72ac0c1ad@huawei.com>
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On Mon, Feb 17, 2020 at 06:38:23PM +0800, zhangyi (F) wrote:
> >> +			/*
> >> +			 * Block device buffers need to stay mapped all the
> >> +			 * time, so it is enough to clear buffer_jbddirty and
> >> +			 * buffer_freed bits. For the file mapping buffers (i.e.
> >> +			 * journalled data) we need to unmap buffer and clear
> >> +			 * more bits. We also need to be careful about the check
> >> +			 * because the data page mapping can get cleared under
> >> +			 * out hands, which alse need not to clear more bits
> > 			   ^^^ our    ^^^^ Maybe I'd rephrase this like:
> > 
> > ... under our hands. Note that if mapping == NULL, we don't need to make
> > buffer unmapped because the page is already detached from the mapping and
> > buffers cannot get reused.
> > 
> Thanks for your suggestion, Ted has already pushed this patch to upstream,
> I could write an appending patch to fix this.

Feel free to send a patch to fix up the comment if you like.

Thanks,

					- Ted