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 X-Spam-Level: X-Spam-Status: No, score=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 163B0C07E95 for ; Tue, 20 Jul 2021 01:33:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE8D461175 for ; Tue, 20 Jul 2021 01:33:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235756AbhGTAwX (ORCPT ); Mon, 19 Jul 2021 20:52:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:47398 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236874AbhGTAu0 (ORCPT ); Mon, 19 Jul 2021 20:50:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D6A8C6115B; Tue, 20 Jul 2021 01:29:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626744585; bh=PylUwAl+xcXt4KK9dSrgWcx8BRZ08iQRRV5ddM1yetU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fGJonETlzbajpqBeoOiUxqonmHUmA1Omfuja27RxGvrDQ2sXvKwLGNgYTUVTfWLSw DF+ZsNY2Pnq/KGWk3Njqeb9FsqM1UFRby1XGg3fHaM1jcoZxQBsq16bVCG6+MN9w+f hEzEEKLHmF8R2VstG+GwdTX9B0CPEkjraNaPNz1GIpVcXZso8lIZSH4AZ2BufW9Uvi 2gE3Xm1Zbnpy2wO895cBGqD1rKEjMoPOuRtCPfBhtshTgpvR1LGuXU24007YKIxtyU BHzWTfEOHuyrC6zoFfrgGBz2+ji0hxg2JMNDDiFaBVl5v2IJh/7zOrJUgoxrKJhDLc DSrhdK2hLIGgg== Date: Mon, 19 Jul 2021 18:29:45 -0700 From: "Darrick J. Wong" To: "Matthew Wilcox (Oracle)" Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org Subject: Re: [PATCH v15 02/17] block: Add bio_for_each_folio_all() Message-ID: <20210720012945.GO22357@magnolia> References: <20210719184001.1750630-1-willy@infradead.org> <20210719184001.1750630-3-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210719184001.1750630-3-willy@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Jul 19, 2021 at 07:39:46PM +0100, 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) Whoops, I never did remember to circle back and ack this patch. 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 2a7444e3a4c2..b804605f705e 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 ade93e2de6a1..a90a79ad7bd1 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -189,7 +189,7 @@ static inline void bio_advance_iter_single(const struct bio *bio, > */ > #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) > > @@ -314,6 +314,57 @@ 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 */ > -- > 2.30.2 >