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Date: Mon, 31 Oct 2016 08:40:21 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Ming Lei <tom.leiming@gmail.com>
Cc: Jens Axboe <axboe@fb.com>, linux-kernel@vger.kernel.org,
        linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        Christoph Hellwig <hch@infradead.org>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH 46/60] block: deal with dirtying pages for multipage bvec
Message-ID: <20161031154021.GM30919@infradead.org>
References: <1477728600-12938-1-git-send-email-tom.leiming@gmail.com>
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On Sat, Oct 29, 2016 at 04:08:45PM +0800, Ming Lei wrote:
> In bio_check_pages_dirty(), bvec->bv_page is used as flag
> for marking if the page has been dirtied & released, and if
> no, it will be dirtied in deferred workqueue.
> 
> With multipage bvec, we can't do that any more, so change
> the logic into checking all pages in one mp bvec, and only
> release all these pages if all are dirtied, otherwise dirty
> them all in deferred wrokqueue.

Just defer the whole bio to the workqueue if we need to redirty any,
that avoids having all these complex iteratations.