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Date: Fri, 23 Jan 2026 09:35:54 +0100
From: Christoph Hellwig <hch@lst.de>
To: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
	Christian Brauner <brauner@kernel.org>,
	"Darrick J. Wong" <djwong@kernel.org>,
	Carlos Maiolino <cem@kernel.org>, Qu Wenruo <wqu@suse.com>,
	Al Viro <viro@zeniv.linux.org.uk>, linux-block@vger.kernel.org,
	linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 01/14] block: refactor get_contig_folio_len
Message-ID: <20260123083554.GA30708@lst.de>
References: <20260119074425.4005867-1-hch@lst.de> <20260119074425.4005867-2-hch@lst.de> <824538a6-ce9d-41e7-9485-10ff9e4d5334@kernel.org>
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On Fri, Jan 23, 2026 at 07:32:04PM +1100, Damien Le Moal wrote:
> > -	unsigned int j;
> > +	struct folio *folio = page_folio(pages[0]);
> > +	size_t contig_sz = min_t(size_t, PAGE_SIZE - offset, left);
> > +	unsigned int max_pages, i;
> > +	size_t folio_offset, len;
> > +
> > +	folio_offset = PAGE_SIZE * folio_page_idx(folio, pages[0]) + offset;
> 
> folio_page_idx(folio, pages[0]) is always going to be 0 here, no ?

No, page could be at an offset into the folio.