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Date:   Sun, 27 Feb 2022 14:12:39 -0800
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Subject: Re: [PATCH 3/6] block, fs: assert that key paths use iovecs, and
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To:     Jens Axboe <axboe@kernel.dk>, jhubbard.send.patches@gmail.com,
        Jan Kara <jack@suse.cz>, Christoph Hellwig <hch@infradead.org>,
        Dave Chinner <dchinner@redhat.com>,
        "Darrick J . Wong" <djwong@kernel.org>,
        Theodore Ts'o <tytso@mit.edu>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Miklos Szeredi <miklos@szeredi.hu>,
        Andrew Morton <akpm@linux-foundation.org>,
        Chaitanya Kulkarni <kch@nvidia.com>
Cc:     linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-xfs@vger.kernel.org, linux-mm@kvack.org,
        LKML <linux-kernel@vger.kernel.org>
References: <20220227093434.2889464-1-jhubbard@nvidia.com>
 <20220227093434.2889464-4-jhubbard@nvidia.com>
 <5935986f-bbbf-fa90-2eba-b249ca7e15e1@kernel.dk>
From:   John Hubbard <jhubbard@nvidia.com>
In-Reply-To: <5935986f-bbbf-fa90-2eba-b249ca7e15e1@kernel.dk>
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On 2/27/22 13:58, Jens Axboe wrote:
>> diff --git a/block/bio.c b/block/bio.c
>> index b15f5466ce08..4679d6539e2d 100644
>> --- a/block/bio.c
>> +++ b/block/bio.c
>> @@ -1167,6 +1167,8 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
>>   	BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2);
>>   	pages += entries_left * (PAGE_PTRS_PER_BVEC - 1);
>>   
>> +	WARN_ON_ONCE(!iter_is_iovec(iter));
>> +
> 
> If these make sense, why aren't they also returning an error?
> 

Oops. Got caught up in the luxury of local testing and watching the
logs, but also returning errors is of course the right answer. Will fix.

thanks,
-- 
John Hubbard
NVIDIA