From patchwork Mon May 23 06:59:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hsin-Yi Wang X-Patchwork-Id: 12858489 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 76715C433F5 for ; Mon, 23 May 2022 07:00:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 14D0A6B0008; Mon, 23 May 2022 03:00:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0FD8D6B000A; Mon, 23 May 2022 03:00:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F2E856B000C; Mon, 23 May 2022 03:00:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id E33006B0008 for ; Mon, 23 May 2022 03:00:13 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id B5213DAF for ; Mon, 23 May 2022 07:00:13 +0000 (UTC) X-FDA: 79496108706.14.1D9E2F2 Received: from mail-pf1-f178.google.com (mail-pf1-f178.google.com [209.85.210.178]) by imf21.hostedemail.com (Postfix) with ESMTP id ED3B21C0026 for ; Mon, 23 May 2022 07:00:01 +0000 (UTC) Received: by mail-pf1-f178.google.com with SMTP id y199so12852299pfb.9 for ; Mon, 23 May 2022 00:00:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=n/ak3fxbDlmFRvOmVIgctXK5enM9fzzhqOEs66o/WZM=; b=BJYsjmLTVsLt/DTcxdKUZlCPRaGxYqNgQ3iPjE0uaCVFHbQ5IfcSm2bRKpCOy1sKyB P8SRFu76e4eKYu2KV3zIGjFcZQz/o/iMiGBWw6KU64KmqHFC1s2lZDKrqqSxtW6As6L0 iXUZ6q4c8IEnzqZTeXStFgBDuLzkBwg/vZEYc= 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=n/ak3fxbDlmFRvOmVIgctXK5enM9fzzhqOEs66o/WZM=; b=SG/YgFghU7DSAsp8lL+ilYnpVcKTw4rUJaRxR89Gn8QeA9iVkUUaQWebw+bvfZo3ce Bu+0TRFDWfteuXRqil5Dj3+RvDZytyRqPqTgcH/Xrc+C2NHBQKKaEphPMBtufAuILneb fOqc4YTbIFGiQnZBOP/GLnOwTPeP+nUS+cbv1qeWkxUHTFcQzv7Bif0XfBOvMpkmpHmT 8FnOZkmpa+CNiFOvdaPu8RqK53dwdEhdkDfCe9yPhBvwlIo4RpNfCFt8B4LeiivewHDG aXJc7aeIzeU5Tno1w3KvZMsj+SdfAk+EF3lc+eQH/8qQZqcYmzEKMeSekvAHeiwxifyR Pzgw== X-Gm-Message-State: AOAM530674AijIdrsgC+h1jHBE2GXeX4DgenGDXBblwf+FPWMR0tRWXO vpxgnJQTvH8YTYQd8b76UlEFbg== X-Google-Smtp-Source: ABdhPJwEV3eRY3ezvap02NItAMRg3nkr6LiufW/9apHU0swp7gID6uukw67Oyat2knY8vtCPnx9gMw== X-Received: by 2002:a05:6a00:a85:b0:506:b9e:7f43 with SMTP id b5-20020a056a000a8500b005060b9e7f43mr22302851pfl.5.1653289212266; Mon, 23 May 2022 00:00:12 -0700 (PDT) Received: from hsinyi-z840.tpe.corp.google.com ([2401:fa00:1:10:76d5:494d:1690:d003]) by smtp.gmail.com with ESMTPSA id m2-20020a629402000000b005180f4733a8sm3099527pfe.106.2022.05.23.00.00.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 May 2022 00:00:11 -0700 (PDT) From: Hsin-Yi Wang To: Phillip Lougher , Matthew Wilcox , Xiongwei Song Cc: Zheng Liang , Zhang Yi , Hou Tao , Miao Xie , Andrew Morton , "linux-mm @ kvack . org" , "squashfs-devel @ lists . sourceforge . net" , linux-kernel@vger.kernel.org Subject: [PATCH v3 3/3] squashfs: implement readahead Date: Mon, 23 May 2022 14:59:13 +0800 Message-Id: <20220523065909.883444-4-hsinyi@chromium.org> X-Mailer: git-send-email 2.36.1.124.g0e6072fb45-goog In-Reply-To: <20220523065909.883444-1-hsinyi@chromium.org> References: <20220523065909.883444-1-hsinyi@chromium.org> MIME-Version: 1.0 X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: ED3B21C0026 X-Stat-Signature: bmkn4aoa3tud16tf4mzz15qgk8a6s8jg X-Rspam-User: Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=BJYsjmLT; dmarc=pass (policy=none) header.from=chromium.org; spf=pass (imf21.hostedemail.com: domain of hsinyi@chromium.org designates 209.85.210.178 as permitted sender) smtp.mailfrom=hsinyi@chromium.org X-HE-Tag: 1653289201-418819 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: Implement readahead callback for squashfs. It will read datablocks which cover pages in readahead request. For a few cases it will not mark page as uptodate, including: - file end is 0. - zero filled blocks. - current batch of pages isn't in the same datablock or not enough in a datablock. - decompressor error. Otherwise pages will be marked as uptodate. The unhandled pages will be updated by readpage later. Suggested-by: Matthew Wilcox Signed-off-by: Hsin-Yi Wang Reported-by: Matthew Wilcox Reported-by: Phillip Lougher Reported-by: Xiongwei Song --- v2->v3: Add checks on - decompressed block size. - fill zeros if the last page is not a full page. v2: https://lore.kernel.org/lkml/20220517082650.2005840-4-hsinyi@chromium.org/ v1: https://lore.kernel.org/lkml/20220516105100.1412740-3-hsinyi@chromium.org/ --- fs/squashfs/file.c | 91 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 90 insertions(+), 1 deletion(-) diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c index a8e495d8eb86..c311fc685fe4 100644 --- a/fs/squashfs/file.c +++ b/fs/squashfs/file.c @@ -39,6 +39,7 @@ #include "squashfs_fs_sb.h" #include "squashfs_fs_i.h" #include "squashfs.h" +#include "page_actor.h" /* * Locate cache slot in range [offset, index] for specified inode. If @@ -495,7 +496,95 @@ static int squashfs_read_folio(struct file *file, struct folio *folio) return 0; } +static void squashfs_readahead(struct readahead_control *ractl) +{ + struct inode *inode = ractl->mapping->host; + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + size_t mask = (1UL << msblk->block_log) - 1; + size_t shift = msblk->block_log - PAGE_SHIFT; + loff_t start = readahead_pos(ractl) &~ mask; + size_t len = readahead_length(ractl) + readahead_pos(ractl) - start; + struct squashfs_page_actor *actor; + unsigned int nr_pages = 0; + struct page **pages; + u64 block = 0; + int bsize, res, i, index, bytes, expected; + int file_end = i_size_read(inode) >> msblk->block_log; + unsigned int max_pages = 1UL << shift; + void *pageaddr; + + readahead_expand(ractl, start, (len | mask) + 1); + + if (file_end == 0) + return; + + pages = kmalloc_array(max_pages, sizeof(void *), GFP_KERNEL); + if (!pages) + return; + + actor = squashfs_page_actor_init_special(pages, max_pages, 0); + if (!actor) + goto out; + + for (;;) { + nr_pages = __readahead_batch(ractl, pages, max_pages); + if (!nr_pages) + break; + + if (readahead_pos(ractl) >= i_size_read(inode) || + nr_pages < max_pages) + goto skip_pages; + + index = pages[0]->index >> shift; + if ((pages[nr_pages - 1]->index >> shift) != index) + goto skip_pages; + + expected = index == file_end ? + (i_size_read(inode) & (msblk->block_size - 1)) : + msblk->block_size; + + bsize = read_blocklist(inode, index, &block); + if (bsize == 0) + goto skip_pages; + + res = squashfs_read_data(inode->i_sb, block, bsize, NULL, + actor); + + if (res == expected) { + /* Last page may have trailing bytes not filled */ + bytes = res % PAGE_SIZE; + if (bytes) { + pageaddr = kmap_atomic(pages[nr_pages - 1]); + memset(pageaddr + bytes, 0, PAGE_SIZE - bytes); + kunmap_atomic(pageaddr); + } + + for (i = 0; i < nr_pages; i++) + SetPageUptodate(pages[i]); + } + + for (i = 0; i < nr_pages; i++) { + unlock_page(pages[i]); + put_page(pages[i]); + } + } + + kfree(actor); + kfree(pages); + return; + +skip_pages: + for (i = 0; i < nr_pages; i++) { + unlock_page(pages[i]); + put_page(pages[i]); + } + + kfree(actor); +out: + kfree(pages); +} const struct address_space_operations squashfs_aops = { - .read_folio = squashfs_read_folio + .read_folio = squashfs_read_folio, + .readahead = squashfs_readahead };