From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5883CC433FE for ; Wed, 17 Nov 2021 04:48:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 354CE63212 for ; Wed, 17 Nov 2021 04:48:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231356AbhKQEvg (ORCPT ); Tue, 16 Nov 2021 23:51:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:50486 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230362AbhKQEvg (ORCPT ); Tue, 16 Nov 2021 23:51:36 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1A640617E4; Wed, 17 Nov 2021 04:48:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637124518; bh=PaCQK9OcWvVCxVcVFvUIIp+dLbwqCFPxSiJVxDpNV18=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kwfDRIcPmvU0duRN65O39l5QjUFh0jQ9kjZLHLdynWUyubQbPDP2Ckm3D0daybUdl s4Kgjw+RIcdd0jJv2EYFbDNGoHevLfYyrSHXzwJ443cbz0ibh9X53Oy0KkOHGw4upE NLRDF9gLgSQIvO4LtIJ2EnaIuSmS9vNRCoLQlOL3x25SxE/uB8QRqEzbOn8y3TQTde cD0rWPc4iBgHC/gB07X+OTdYf7Uk/H9ZQpNDH4hzT76LsriCLczSKgS7u8qkCPRqJx FJyzP/2iIGYJBG6SikeCDdLxHhw3Fyp/qia1txuLeolGzBl9Cg6iC5HnPugl7Y8mbp pc5RIW7bUaWzg== Date: Tue, 16 Nov 2021 20:48:37 -0800 From: "Darrick J. Wong" To: "Matthew Wilcox (Oracle)" Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Jens Axboe , Christoph Hellwig , Christoph Hellwig Subject: Re: [PATCH v2 06/28] block: Add bio_for_each_folio_all() Message-ID: <20211117044837.GQ24307@magnolia> References: <20211108040551.1942823-1-willy@infradead.org> <20211108040551.1942823-7-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211108040551.1942823-7-willy@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Nov 08, 2021 at 04:05:29AM +0000, Matthew Wilcox (Oracle) wrote: > Allow callers to iterate over each folio instead of each page. The > bio need not have been constructed using folios originally. > > Signed-off-by: Matthew Wilcox (Oracle) > Reviewed-by: Jens Axboe > Reviewed-by: Christoph Hellwig Looks ok, Reviewed-by: Darrick J. Wong --D > --- > Documentation/core-api/kernel-api.rst | 1 + > include/linux/bio.h | 53 ++++++++++++++++++++++++++- > 2 files changed, 53 insertions(+), 1 deletion(-) > > diff --git a/Documentation/core-api/kernel-api.rst b/Documentation/core-api/kernel-api.rst > index 2e7186805148..7f0cb604b6ab 100644 > --- a/Documentation/core-api/kernel-api.rst > +++ b/Documentation/core-api/kernel-api.rst > @@ -279,6 +279,7 @@ Accounting Framework > Block Devices > ============= > > +.. kernel-doc:: include/linux/bio.h > .. kernel-doc:: block/blk-core.c > :export: > > diff --git a/include/linux/bio.h b/include/linux/bio.h > index a783cac49978..e3c9e8207f12 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -166,7 +166,7 @@ static inline void bio_advance(struct bio *bio, unsigned int nbytes) > */ > #define bio_for_each_bvec_all(bvl, bio, i) \ > for (i = 0, bvl = bio_first_bvec_all(bio); \ > - i < (bio)->bi_vcnt; i++, bvl++) \ > + i < (bio)->bi_vcnt; i++, bvl++) > > #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len) > > @@ -260,6 +260,57 @@ static inline struct bio_vec *bio_last_bvec_all(struct bio *bio) > return &bio->bi_io_vec[bio->bi_vcnt - 1]; > } > > +/** > + * struct folio_iter - State for iterating all folios in a bio. > + * @folio: The current folio we're iterating. NULL after the last folio. > + * @offset: The byte offset within the current folio. > + * @length: The number of bytes in this iteration (will not cross folio > + * boundary). > + */ > +struct folio_iter { > + struct folio *folio; > + size_t offset; > + size_t length; > + /* private: for use by the iterator */ > + size_t _seg_count; > + int _i; > +}; > + > +static inline void bio_first_folio(struct folio_iter *fi, struct bio *bio, > + int i) > +{ > + struct bio_vec *bvec = bio_first_bvec_all(bio) + i; > + > + fi->folio = page_folio(bvec->bv_page); > + fi->offset = bvec->bv_offset + > + PAGE_SIZE * (bvec->bv_page - &fi->folio->page); > + fi->_seg_count = bvec->bv_len; > + fi->length = min(folio_size(fi->folio) - fi->offset, fi->_seg_count); > + fi->_i = i; > +} > + > +static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio) > +{ > + fi->_seg_count -= fi->length; > + if (fi->_seg_count) { > + fi->folio = folio_next(fi->folio); > + fi->offset = 0; > + fi->length = min(folio_size(fi->folio), fi->_seg_count); > + } else if (fi->_i + 1 < bio->bi_vcnt) { > + bio_first_folio(fi, bio, fi->_i + 1); > + } else { > + fi->folio = NULL; > + } > +} > + > +/** > + * bio_for_each_folio_all - Iterate over each folio in a bio. > + * @fi: struct folio_iter which is updated for each folio. > + * @bio: struct bio to iterate over. > + */ > +#define bio_for_each_folio_all(fi, bio) \ > + for (bio_first_folio(&fi, bio, 0); fi.folio; bio_next_folio(&fi, bio)) > + > enum bip_flags { > BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */ > BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */ > -- > 2.33.0 >