From patchwork Fri Dec 3 15:38:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 12655399 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A751C433F5 for ; Fri, 3 Dec 2021 15:39:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EFE266B0075; Fri, 3 Dec 2021 10:38:46 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EAD8B6B0078; Fri, 3 Dec 2021 10:38:46 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D75296B007B; Fri, 3 Dec 2021 10:38:46 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0084.hostedemail.com [216.40.44.84]) by kanga.kvack.org (Postfix) with ESMTP id C8F836B0075 for ; Fri, 3 Dec 2021 10:38:46 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 8B8091813CB88 for ; Fri, 3 Dec 2021 15:38:36 +0000 (UTC) X-FDA: 78876890232.16.CC0BD99 Received: from mail-il1-f170.google.com (mail-il1-f170.google.com [209.85.166.170]) by imf01.hostedemail.com (Postfix) with ESMTP id 1F7F040002 for ; Fri, 3 Dec 2021 15:38:35 +0000 (UTC) Received: by mail-il1-f170.google.com with SMTP id h16so3087337ila.4 for ; Fri, 03 Dec 2021 07:38:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=n0F2twjIx4NmxUZNO6rvzL0OidoPYFlJudXfQWPXRJI=; b=HOYS28dB+hf7PjSdhk0KEDvwuC5KVLlJPN5YqZZZeFpwh8+wgfG6WE3Y7xlAXUNK00 riELvOdzKOTEmTmSBb+trw1x9oUpxw1UZqyOjnz0zLRLXYcMCcS3dmjaOmUffQVxQyWs 4VeJjqwe+mOtQ3u133rotKSCR5U3vawPNBedcF8wtFZrah9Ajeb42I9KLxdKj2NWFEz0 QvdC9dbengdqfr5dpD50D/WlahrRAOc/wEUI6yZgsHVrufF5mOX6Zcih6rKfmf3jVo/D nD3idtZJws1ItQ71mu/xBTJWti1NjCa85o7CVYgFxv2x/IhSO9uVmXXEEPD6/2MAedbG bScw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=n0F2twjIx4NmxUZNO6rvzL0OidoPYFlJudXfQWPXRJI=; b=Z4v79uh5qZdCBHMW1k8NJJ0fOwEhquW+kes+44AkRAahaQ4w+jKF72HBrvUJ42knDp untSy/pKjYvwahNnGa6pUoUOUtiwsMoHXhG6zjkBjaYo1bYGSYSAdJ/8g2ipmywGSvHd z0Txw36H0cG04uxSs/qqpr9+4+dV2jth3bJY6Rq2ounAiL+dZvAgrokH4raKreje6P7P 94AwwQpxmfkYiT7uDGa5EFPLGNSf3LgHA8mVC6YCP/eecwgE23x7QmP1hgU1vjdZJIi6 OBuR5mEeKIHdx7MN5y+DcGAS9wCMupzWhA58mlS5faN+Nc+dAHosDxvnKwcT6JkSchHl GCeg== X-Gm-Message-State: AOAM5313kd8wVcIgQv1ZPp2oPRJFoEZvzGsoPsI6zQWAag9J0jXSLS1A nbBw72B3v4qofif8GsXOaA4g9w== X-Google-Smtp-Source: ABdhPJypBb2scW85GQGRdq2BTbwmtkv74gMtEvSbk1YgLbiD/4HFcK6ryenFEVuW9Pac/1fyDooBww== X-Received: by 2002:a92:4a04:: with SMTP id m4mr18093924ilf.103.1638545915002; Fri, 03 Dec 2021 07:38:35 -0800 (PST) Received: from p1.localdomain ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id c15sm1753042ilq.50.2021.12.03.07.38.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Dec 2021 07:38:34 -0800 (PST) From: Jens Axboe To: linux-block@vger.kernel.org, linux-mm@kvack.org Cc: Jens Axboe Subject: [PATCH 2/2] block: move direct_IO into our own read_iter handler Date: Fri, 3 Dec 2021 08:38:29 -0700 Message-Id: <20211203153829.298893-3-axboe@kernel.dk> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211203153829.298893-1-axboe@kernel.dk> References: <20211203153829.298893-1-axboe@kernel.dk> MIME-Version: 1.0 X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 1F7F040002 X-Stat-Signature: sews4tmhr6ff5gfabj7xuhdy78arjop4 Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=kernel-dk.20210112.gappssmtp.com header.s=20210112 header.b=HOYS28dB; spf=pass (imf01.hostedemail.com: domain of axboe@kernel.dk designates 209.85.166.170 as permitted sender) smtp.mailfrom=axboe@kernel.dk; dmarc=none X-HE-Tag: 1638545915-139271 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Don't call into generic_file_read_iter() if we know it's O_DIRECT, just set it up ourselves and call our own handler. This avoids an indirect call for O_DIRECT. Fall back to filemap_read() if we fail. Signed-off-by: Jens Axboe --- block/fops.c | 37 ++++++++++++++++++++++++++++++++----- 1 file changed, 32 insertions(+), 5 deletions(-) diff --git a/block/fops.c b/block/fops.c index 93bb5bf66f69..10015e1a5b01 100644 --- a/block/fops.c +++ b/block/fops.c @@ -566,21 +566,48 @@ static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) { struct block_device *bdev = iocb->ki_filp->private_data; loff_t size = bdev_nr_bytes(bdev); + size_t count = iov_iter_count(to); loff_t pos = iocb->ki_pos; size_t shorted = 0; - ssize_t ret; + ssize_t ret = 0; - if (unlikely(pos + iov_iter_count(to) > size)) { + if (unlikely(pos + count > size)) { if (pos >= size) return 0; size -= pos; - if (iov_iter_count(to) > size) { - shorted = iov_iter_count(to) - size; + if (count > size) { + shorted = count - size; iov_iter_truncate(to, size); } } - ret = generic_file_read_iter(iocb, to); + if (iocb->ki_flags & IOCB_DIRECT) { + struct address_space *mapping = iocb->ki_filp->f_mapping; + + if (iocb->ki_flags & IOCB_NOWAIT) { + if (filemap_range_needs_writeback(mapping, iocb->ki_pos, + iocb->ki_pos + count - 1)) + return -EAGAIN; + } else { + ret = filemap_write_and_wait_range(mapping, + iocb->ki_pos, + iocb->ki_pos + count - 1); + if (ret < 0) + return ret; + } + + file_accessed(iocb->ki_filp); + + ret = blkdev_direct_IO(iocb, to); + if (ret >= 0) { + iocb->ki_pos += ret; + count -= ret; + } + if (ret < 0 || !count) + return ret; + } + + ret = filemap_read(iocb, to, ret); if (unlikely(shorted)) iov_iter_reexpand(to, iov_iter_count(to) + shorted);