From patchwork Fri Dec 3 15:38:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 12655389 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B37D8C433F5 for ; Fri, 3 Dec 2021 15:38:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381876AbhLCPmA (ORCPT ); Fri, 3 Dec 2021 10:42:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381843AbhLCPl7 (ORCPT ); Fri, 3 Dec 2021 10:41:59 -0500 Received: from mail-il1-x132.google.com (mail-il1-x132.google.com [IPv6:2607:f8b0:4864:20::132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A162C061359 for ; Fri, 3 Dec 2021 07:38:35 -0800 (PST) Received: by mail-il1-x132.google.com with SMTP id a11so3087671ilj.6 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=4DFUFvaV0G/Q7jMqV2RbUUz9oX67OaVlTxzTJrNM/Ao=; b=US11acHjTsIZlHpwqc0CpkAopjX/F5w0mftn0NuN4EDfAAQooNYA9xLEhw5iAM323n 7qmNVtAAwmRGZ629l9uQibQFdzyhBn3Hmi4rNPJBse095i1lL4Rf6hsHskPDU85pVEpw s9M04LXnIC9YJIWREWtBmilPyEa2S7hkKulF8yl0/CAHowduzlhMSR2a+7HNzgcGyUPP IqWkBlhrWC3CAjm5maf5prTyjj3ij37qmA1sFel7FeQGbzQgTydxDL64jtXSgAlBW77+ WmJfmlFtjbokqGU2i+vlQd7oMIVjwb3qfMRNeqWBsNPcRZaH3XOp7hDAQhnOiswsYDXJ 7Fjg== 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=4DFUFvaV0G/Q7jMqV2RbUUz9oX67OaVlTxzTJrNM/Ao=; b=tfvJCYRdFR3VDdoC0xyvA1l5z/7xilQyY9vFcCxHzPORK7OHxQ9jSLhqB8Q3mzK0B1 bTr0P4GaP8FivafjAAH/kOvT+lTTk4yQNjiF/TpMBOFJ38FiU5+/WFnU9Zro98gCqNGk W7nvKE2/niglB4qvrfW0XjEsOCazeozfBWKt/SSL0r94xkVv4gSYzMBoB+fQpNOT4ae2 Vjnxsao3yLJfOGLkxbWyDwuXfT72LyHEq9IdNPh6g84pnRuroOXDE8YlLKOFKcbqjHc2 ldjgpU6cOHM96oskDhq0zW8yB1nV44S/+iaHsjFealKztNQjXsVpyUS0uTZoyoqE6eAK 3sEw== X-Gm-Message-State: AOAM531xdficVuzJiEoul1lNXPTZC+Vw1k7Arr8y8njgsr0fuyAokox7 QOt2qdYC+zG9fWeV34Ib+aWSPYA8P4fKqJ81 X-Google-Smtp-Source: ABdhPJxF5B/TooZb00Dmyre+qqFISBooHUDLdPHCH1GXfo3mnLG1tprnmFTQZC7G9sMIsZ9oBk4wCw== X-Received: by 2002:a92:d24e:: with SMTP id v14mr18550782ilg.55.1638545914395; Fri, 03 Dec 2021 07:38:34 -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 1/2] mm: move filemap_range_needs_writeback() into header Date: Fri, 3 Dec 2021 08:38:28 -0700 Message-Id: <20211203153829.298893-2-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 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org No functional changes in this patch, just in preparation for efficiently calling this light function from the block O_DIRECT handling. Signed-off-by: Jens Axboe Reviewed-by: Matthew Wilcox (Oracle) --- include/linux/fs.h | 35 +++++++++++++++++++++++++++++++++++ mm/filemap.c | 38 +++----------------------------------- 2 files changed, 38 insertions(+), 35 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index bbf812ce89a8..0cc4f5fd4cfe 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2845,6 +2845,41 @@ static inline int filemap_fdatawait(struct address_space *mapping) return filemap_fdatawait_range(mapping, 0, LLONG_MAX); } +/* Returns true if writeback might be needed or already in progress. */ +static inline bool mapping_needs_writeback(struct address_space *mapping) +{ + return mapping->nrpages; +} + +bool filemap_range_has_writeback(struct address_space *mapping, + loff_t start_byte, loff_t end_byte); + +/** + * filemap_range_needs_writeback - check if range potentially needs writeback + * @mapping: address space within which to check + * @start_byte: offset in bytes where the range starts + * @end_byte: offset in bytes where the range ends (inclusive) + * + * Find at least one page in the range supplied, usually used to check if + * direct writing in this range will trigger a writeback. Used by O_DIRECT + * read/write with IOCB_NOWAIT, to see if the caller needs to do + * filemap_write_and_wait_range() before proceeding. + * + * Return: %true if the caller should do filemap_write_and_wait_range() before + * doing O_DIRECT to a page in this range, %false otherwise. + */ +static inline bool filemap_range_needs_writeback(struct address_space *mapping, + loff_t start_byte, + loff_t end_byte) +{ + if (!mapping_needs_writeback(mapping)) + return false; + if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) && + !mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) + return false; + return filemap_range_has_writeback(mapping, start_byte, end_byte); +} + extern bool filemap_range_has_page(struct address_space *, loff_t lstart, loff_t lend); extern bool filemap_range_needs_writeback(struct address_space *, diff --git a/mm/filemap.c b/mm/filemap.c index daa0e23a6ee6..65238440fa0a 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -640,14 +640,8 @@ int filemap_fdatawait_keep_errors(struct address_space *mapping) } EXPORT_SYMBOL(filemap_fdatawait_keep_errors); -/* Returns true if writeback might be needed or already in progress. */ -static bool mapping_needs_writeback(struct address_space *mapping) -{ - return mapping->nrpages; -} - -static bool filemap_range_has_writeback(struct address_space *mapping, - loff_t start_byte, loff_t end_byte) +bool filemap_range_has_writeback(struct address_space *mapping, + loff_t start_byte, loff_t end_byte) { XA_STATE(xas, &mapping->i_pages, start_byte >> PAGE_SHIFT); pgoff_t max = end_byte >> PAGE_SHIFT; @@ -667,34 +661,8 @@ static bool filemap_range_has_writeback(struct address_space *mapping, } rcu_read_unlock(); return page != NULL; - -} - -/** - * filemap_range_needs_writeback - check if range potentially needs writeback - * @mapping: address space within which to check - * @start_byte: offset in bytes where the range starts - * @end_byte: offset in bytes where the range ends (inclusive) - * - * Find at least one page in the range supplied, usually used to check if - * direct writing in this range will trigger a writeback. Used by O_DIRECT - * read/write with IOCB_NOWAIT, to see if the caller needs to do - * filemap_write_and_wait_range() before proceeding. - * - * Return: %true if the caller should do filemap_write_and_wait_range() before - * doing O_DIRECT to a page in this range, %false otherwise. - */ -bool filemap_range_needs_writeback(struct address_space *mapping, - loff_t start_byte, loff_t end_byte) -{ - if (!mapping_needs_writeback(mapping)) - return false; - if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) && - !mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) - return false; - return filemap_range_has_writeback(mapping, start_byte, end_byte); } -EXPORT_SYMBOL_GPL(filemap_range_needs_writeback); +EXPORT_SYMBOL_GPL(filemap_range_has_writeback); /** * filemap_write_and_wait_range - write out & wait on a file range 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: 12655391 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38564C433EF for ; Fri, 3 Dec 2021 15:38:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381851AbhLCPmB (ORCPT ); Fri, 3 Dec 2021 10:42:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381867AbhLCPmA (ORCPT ); Fri, 3 Dec 2021 10:42:00 -0500 Received: from mail-il1-x133.google.com (mail-il1-x133.google.com [IPv6:2607:f8b0:4864:20::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 142DEC061353 for ; Fri, 3 Dec 2021 07:38:36 -0800 (PST) Received: by mail-il1-x133.google.com with SMTP id j21so3089724ila.5 for ; Fri, 03 Dec 2021 07:38:36 -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=3MZwkHx40L7awQmscW1UuDiQDgNEFj6JdXkSvpiSNJ52UsETY7+Zl/lFKRPrewKjfg ocI8W54sGyQznirvh+3cwJd2szuH99d+Pcjl4HtHC+y5iS0CHThBupDbFinmDg/qVjeB P5s7y96YidWVwsvqvSjhBOey2zVlJpPan7coEynlhvgnI10mlqPlNZHblqnqb5sY4zw9 Opvw+91cqEeXAc00ldOpmzv1Qb/lpsaASOnJB/OZLY0z9PHqrQTARcCpgKXU0YbRdgPw 63R1U+XrUiUf/bsnx6cxMDcNJImRHg21mknJmpkm1WwYE7QmNRv0VxELixAcLuznh9WM pJ/A== X-Gm-Message-State: AOAM532mIFTYyJy1yKTkKI+aKJ014mqC/bJCDLH/gn0Swehm1w/k+R3p t9EDLQLUpcJiMYoJ/5tQXt98QLzT8nwKkhwK 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 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 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);