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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 04583C4160E for ; Sat, 9 Jan 2021 16:08:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D8CE323A1C for ; Sat, 9 Jan 2021 16:08:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726925AbhAIQIK (ORCPT ); Sat, 9 Jan 2021 11:08:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726058AbhAIQII (ORCPT ); Sat, 9 Jan 2021 11:08:08 -0500 Received: from mail-wr1-x42f.google.com (mail-wr1-x42f.google.com [IPv6:2a00:1450:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C274C0617A6; Sat, 9 Jan 2021 08:06:54 -0800 (PST) Received: by mail-wr1-x42f.google.com with SMTP id i9so11920379wrc.4; Sat, 09 Jan 2021 08:06:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=RwZZxMhI82qZ1NGjjWs3i9PNzY6l2vY31jXhvq/2jzI=; b=Ttko+RVGU3n5aJcKu+1ljJRmO0ZoHSASRWTCu9NUBLQwvAMVtJm4xDctv0HVgar+fN j1+FVNn31Se10pLKpcqpfLj8k/U/bCPpLxmbmyG9XhOQyBjS0P2EzY+bpgmi+CuQUrhJ WIGEIL+T1d4wzj8RPH1EjE4HYVpzd83UevIJJNOzJAvvhyRCV9gTTPu/DFakNUBhjPUE 6YAc1X5PQF2GEWeLQfCtAjB499ILo9qLgoWgjQm1uq5kYEoxQ6UI0jSz1HOqcEDSpjJd uY01F6EMQsqPI6ykkfpm8TNw/LNJIbIiD1vvLsZRCX6bzgxA5GWTjxPV4bsYNY4Ny2/9 EEYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=RwZZxMhI82qZ1NGjjWs3i9PNzY6l2vY31jXhvq/2jzI=; b=fLFT8G3T/77dDHC+cFDrKkF1EG+/9I/IJ4lTztV4/r5D1H+7Y3jRtoajbsurVSWJ2f W5raIE9/GDGDeWVZYd47sTHa9dqKRY1qp/YaGFLoZqbwKNSfAJSzKKpGa1GUSIV0x9ai mPn0YWOAfysDskRRoFeMNTEzjTddoeJTgR2V0tieJSAyycH/i/eYS0k3h+jH0c4R4fEw U8V3yXSKZoPtmI1+rvyqhtO9++QHbYfTZtm03wWaBFvTgPeJcB5ydet/mTSu0GWAA6GO KjKjeOnns01Nv9mYsN2qx15vo7qALiV3rq3OyVa1l2PQXgd8CcY2gYzBL+zz9quzgVlW zn8w== X-Gm-Message-State: AOAM530ZIUsnWvTA29TU4Qn5NUjtMO5Dtzut524QEOGriHtEIbkBRe8T ZUJaU5l0PP1zV0spzizLFiB3n9DUC9Fa1sxM X-Google-Smtp-Source: ABdhPJzoUjsfyBMMnqeq2r+2TVEKl5UD3aKgPfvVrdJFCjILudq2jNC955I3gsW4LTeZMtylLSyYdw== X-Received: by 2002:a5d:4a44:: with SMTP id v4mr8956687wrs.106.1610208412908; Sat, 09 Jan 2021 08:06:52 -0800 (PST) Received: from localhost.localdomain ([185.69.144.125]) by smtp.gmail.com with ESMTPSA id j9sm17403866wrm.14.2021.01.09.08.06.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 09 Jan 2021 08:06:52 -0800 (PST) From: Pavel Begunkov To: linux-block@vger.kernel.org Cc: Jens Axboe , Christoph Hellwig , Matthew Wilcox , Ming Lei , Johannes Weiner , Alexander Viro , "Darrick J . Wong" , "Martin K . Petersen" , Jonathan Corbet , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, target-devel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-doc@vger.kernel.org, Christoph Hellwig Subject: [PATCH v3 6/7] bio: add a helper calculating nr segments to alloc Date: Sat, 9 Jan 2021 16:03:02 +0000 Message-Id: X-Mailer: git-send-email 2.24.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Add a helper function calculating the number of bvec segments we need to allocate to construct a bio. It doesn't change anything functionally, but will be used to not duplicate special cases in the future. Reviewed-by: Christoph Hellwig Signed-off-by: Pavel Begunkov --- fs/block_dev.c | 7 ++++--- fs/iomap/direct-io.c | 9 ++++----- include/linux/bio.h | 10 ++++++++++ 3 files changed, 18 insertions(+), 8 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 3b8963e228a1..6f5bd9950baf 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -416,7 +416,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) dio->size += bio->bi_iter.bi_size; pos += bio->bi_iter.bi_size; - nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES); + nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_PAGES); if (!nr_pages) { bool polled = false; @@ -481,9 +481,10 @@ blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) { int nr_pages; - nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES + 1); - if (!nr_pages) + if (!iov_iter_count(iter)) return 0; + + nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_PAGES + 1); if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_PAGES) return __blkdev_direct_IO_simple(iocb, iter, nr_pages); diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 933f234d5bec..ea1e8f696076 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -250,11 +250,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, orig_count = iov_iter_count(dio->submit.iter); iov_iter_truncate(dio->submit.iter, length); - nr_pages = iov_iter_npages(dio->submit.iter, BIO_MAX_PAGES); - if (nr_pages <= 0) { - ret = nr_pages; + if (!iov_iter_count(dio->submit.iter)) goto out; - } if (need_zeroout) { /* zero out from the start of the block to the write offset */ @@ -263,6 +260,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, iomap_dio_zero(dio, iomap, pos - pad, pad); } + nr_pages = bio_iov_vecs_to_alloc(dio->submit.iter, BIO_MAX_PAGES); do { size_t n; if (dio->error) { @@ -308,7 +306,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, dio->size += n; copied += n; - nr_pages = iov_iter_npages(dio->submit.iter, BIO_MAX_PAGES); + nr_pages = bio_iov_vecs_to_alloc(dio->submit.iter, + BIO_MAX_PAGES); iomap_dio_submit_bio(dio, iomap, bio, pos); pos += n; } while (nr_pages); diff --git a/include/linux/bio.h b/include/linux/bio.h index 1edda614f7ce..d8f9077c43ef 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -10,6 +10,7 @@ #include /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */ #include +#include #define BIO_DEBUG @@ -441,6 +442,15 @@ static inline void bio_wouldblock_error(struct bio *bio) bio_endio(bio); } +/* + * Calculate number of bvec segments that should be allocated to fit data + * pointed by @iter. + */ +static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs) +{ + return iov_iter_npages(iter, max_segs); +} + struct request_queue; extern int submit_bio_wait(struct bio *bio); -- 2.24.0