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Subject: Re: [PATCH] fuse: BUG_ON's correction in fuse_dev_splice_write()
To:     Miklos Szeredi <miklos@szeredi.hu>
Cc:     linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        Andrey Ryabinin <aryabinin@virtuozzo.com>
References: <d99f78a7-31c4-582e-17f5-93e1f0d0e4c2@virtuozzo.com>
 <CAJfpegv-EQhvJUB0AUhJ=Xx8moHHQvkDGe-yUXHENyWvboBU3A@mail.gmail.com>
From:   Vasily Averin <vvs@virtuozzo.com>
Message-ID: <5cb431ed-5fba-0223-2d4f-64efd36c1c24@virtuozzo.com>
Date:   Mon, 19 Aug 2019 09:52:47 +0300
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On 8/1/19 2:01 PM, Miklos Szeredi wrote:
> On Tue, Jul 23, 2019 at 8:33 AM Vasily Averin <vvs@virtuozzo.com> wrote:
>>
>> commit 963545357202 ("fuse: reduce allocation size for splice_write")
>> changed size of bufs array, so first BUG_ON should be corrected too.
>> Second BUG_ON become useless, first one also includes the second check:
>> any unsigned nbuf value cannot be less than 0.
> 
> This patch seems broken: it assumes that pipe->nrbufs doesn't change.
> Have you actually tested it?

You're right, I've missed it.
I've prepared second patch version which fixes first BUG_ON only.
checkpatch.pl also advises to replace BUG_ONs to WARN_ONs and 'unsigned' to 'unsigned int'
however I'm don't understand what it's better here:
- keep all as is, 
- or merge all changes together,
- or do it in separate patches,
- or do something else?

I believe it makes sense to remove BUG_ONs in separate patch, or may be merge it with current one,
but I do not like an idea to fight against bare 'unsigned' in fuse.

Could you please comment it?

Thank you,
	Vasily Averin