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Date:   Tue, 20 Aug 2019 13:16:36 +0800
From:   Gao Xiang <gaoxiang25@huawei.com>
To:     Chandan Rajendra <chandan@linux.ibm.com>
CC:     <tytso@mit.edu>, <ebiggers@kernel.org>,
        <linux-fsdevel@vger.kernel.org>, <linux-ext4@vger.kernel.org>,
        <linux-f2fs-devel@lists.sourceforge.net>,
        <linux-fscrypt@vger.kernel.org>, <chandanrmail@gmail.com>,
        <adilger.kernel@dilger.ca>, <jaegeuk@kernel.org>,
        <yuchao0@huawei.com>, <hch@infradead.org>
Subject: Re: [PATCH V4 5/8] f2fs: Use read_callbacks for decrypting file data
Message-ID: <20190820051635.GF159846@architecture4>
References: <20190816061804.14840-1-chandan@linux.ibm.com>
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 <20190820051236.GE159846@architecture4>
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On Tue, Aug 20, 2019 at 01:12:36PM +0800, Gao Xiang wrote:
> Hi Chandan,
> 
> On Tue, Aug 20, 2019 at 10:35:29AM +0530, Chandan Rajendra wrote:
> > On Friday, August 16, 2019 11:48 AM Chandan Rajendra wrote:
> > > F2FS has a copy of "post read processing" code using which encrypted
> > > file data is decrypted. This commit replaces it to make use of the
> > > generic read_callbacks facility.
> > > 
> > > Signed-off-by: Chandan Rajendra <chandan@linux.ibm.com>
> > 
> > Hi Eric and Ted,
> > 
> > Looks like F2FS requires a lot more flexiblity than what can be offered by
> > read callbacks i.e.
> > 
> > 1. F2FS wants to make use of its own workqueue for decryption, verity and
> >    decompression.
> > 2. F2FS' decompression code is not an FS independent entity like fscrypt and
> >    fsverity. Hence they would need Filesystem specific callback functions to
> >    be invoked from "read callbacks". 
> > 
> > Hence I would suggest that we should drop F2FS changes made in this
> > patchset. Please let me know your thoughts on this.
> 
> Add a word, I have some little concern about post read procession order

FYI. Just a minor concern about its flexibility, not big though.
https://lore.kernel.org/r/20190808042640.GA28630@138/

Thanks,
Gao Xiang

> a bit as I mentioned before, because I'd like to move common EROFS
> decompression code out in the future as well for other fses to use
> after we think it's mature enough.
> 
> It seems the current code mainly addresses eliminating duplicated code,
> therefore I have no idea about that...
> 
> Thanks,
> Gao Xiang
> 
> > 
> > -- 
> > chandan
> > 
> > 
> >