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From:   David Laight <David.Laight@ACULAB.COM>
To:     "'Matthew Wilcox (Oracle)'" <willy@infradead.org>,
        "linux-xfs@vger.kernel.org" <linux-xfs@vger.kernel.org>,
        "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
CC:     "Darrick J . Wong" <darrick.wong@oracle.com>,
        Christoph Hellwig <hch@infradead.org>,
        "linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Dave Kleikamp <shaggy@kernel.org>,
        "jfs-discussion@lists.sourceforge.net" 
        <jfs-discussion@lists.sourceforge.net>,
        Christoph Hellwig <hch@lst.de>,
        "Dave Chinner" <dchinner@redhat.com>
Subject: RE: [PATCH v2 2/9] fs: Introduce i_blocks_per_page
Thread-Topic: [PATCH v2 2/9] fs: Introduce i_blocks_per_page
Thread-Index: AQHWh8zSUX5EB+iAm0+PkXaO9U0VzKlp3UwQ
Date:   Tue, 15 Sep 2020 15:40:52 +0000
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 <20200910234707.5504-3-willy@infradead.org>
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From: Matthew Wilcox (Oracle)
> Sent: 11 September 2020 00:47
> This helper is useful for both THPs and for supporting block size larger
> than page size.  Convert all users that I could find (we have a few
> different ways of writing this idiom, and I may have missed some).
> 
...
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index d81a9a86c5aa..330f86b825d7 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -46,7 +46,7 @@ iomap_page_create(struct inode *inode, struct page *page)
>  {
>  	struct iomap_page *iop = to_iomap_page(page);
> 
> -	if (iop || i_blocksize(inode) == PAGE_SIZE)
> +	if (iop || i_blocks_per_page(inode, page) <= 1)
>  		return iop;
> 
>  	iop = kmalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);
> @@ -147,7 +147,7 @@ iomap_iop_set_range_uptodate(struct page *page, unsigned off, unsigned len)
>  	unsigned int i;
> 
>  	spin_lock_irqsave(&iop->uptodate_lock, flags);
> -	for (i = 0; i < PAGE_SIZE / i_blocksize(inode); i++) {
> +	for (i = 0; i < i_blocks_per_page(inode, page); i++) {

You probably don't want to call the helper every time
around the loop.

	David

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