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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB5E1C43334 for ; Mon, 6 Jun 2022 15:03:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 831296B0074; Mon, 6 Jun 2022 11:03:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7E4798D0003; Mon, 6 Jun 2022 11:03:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 67E1B8D0002; Mon, 6 Jun 2022 11:03:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 595E26B0074 for ; Mon, 6 Jun 2022 11:03:21 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 2F7B0349F7 for ; Mon, 6 Jun 2022 15:03:21 +0000 (UTC) X-FDA: 79548129402.26.581A22E Received: from mail-pj1-f46.google.com (mail-pj1-f46.google.com [209.85.216.46]) by imf09.hostedemail.com (Postfix) with ESMTP id 05C93140016 for ; Mon, 6 Jun 2022 15:03:03 +0000 (UTC) Received: by mail-pj1-f46.google.com with SMTP id w2-20020a17090ac98200b001e0519fe5a8so12768402pjt.4 for ; Mon, 06 Jun 2022 08:03:20 -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=78qlS0+VzMo9YnbPE8S51ZKOVHUk72X1BTb4Y0KDRy4=; b=em8v3f6IPRDCDduD4h0KpWCx4D9FyrCgpGffTuHZLi/MLHUDKn/o23wxP90AQnNC57 72ErI/a8d3rwXKMsRhqB0p5BXIFLsOIqF7HZcyj7OCogfV81tkggLBafj2kdyX6C0zuN SsVBcexcgsRUES6LchEm33Lkc1bT0v06qGr10= 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=78qlS0+VzMo9YnbPE8S51ZKOVHUk72X1BTb4Y0KDRy4=; b=zygxdiiLpycyEAB90Bh8BSwhfvVe1iApufCmQeQvTamQP5BEXp9CFopFa/OWIrVft9 hqfhOkhPSrkXgrHcZJ1W5ThzMhOd3SApl4BqqE3qPi7kgOUOrIjouVFtPFFsrlkY5XzB u9eFlVbjus0PO24o5cRtRdFV1AbsnvI24zXDZhIW1uFejIEu0e9qAkPtrWi0GyYNuR0S /KKLPY9XovgTGX/wCOc3YF1/nlfdOAt4MN/9pygKqJ6sPOo8MJ2fHjVnVPpyXI9qvf1j IGa6YXtUKholIkxtkIlHxJxRKFfo0STDZyYGeBl0wYnThGx0wDBnrA6chu4rra3HkvX2 RjXQ== X-Gm-Message-State: AOAM531eNtP6n6mBkEABIKWj4A4GgjBdQW7VX61yY1bQtmDebj5MnnrU GuMhmSwdbD0mi7yKJyOk0asZLA== X-Google-Smtp-Source: ABdhPJzBGeo49gx5Piq2s8WNtXs8Dv8AMd8JEeGehwBIELwlmnaoWhNZHOitb6G5zWU0YW52xIWhtA== X-Received: by 2002:a17:90b:38c8:b0:1e8:5202:f6d4 with SMTP id nn8-20020a17090b38c800b001e85202f6d4mr14524346pjb.149.1654527799750; Mon, 06 Jun 2022 08:03:19 -0700 (PDT) Received: from hsinyi-z840.tpe.corp.google.com ([2401:fa00:1:10:a0a:5e4:e24:c8c4]) by smtp.gmail.com with ESMTPSA id k13-20020aa7998d000000b0050dc76281ecsm7468864pfh.198.2022.06.06.08.03.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Jun 2022 08:03:19 -0700 (PDT) From: Hsin-Yi Wang To: Phillip Lougher , Matthew Wilcox , Xiongwei Song , Marek Szyprowski , Andrew Morton Cc: Zheng Liang , Zhang Yi , Hou Tao , Miao Xie , "linux-mm @ kvack . org" , "squashfs-devel @ lists . sourceforge . net" , linux-kernel@vger.kernel.org Subject: [PATCH v5 3/3] squashfs: implement readahead Date: Mon, 6 Jun 2022 23:03:05 +0800 Message-Id: <20220606150305.1883410-4-hsinyi@chromium.org> X-Mailer: git-send-email 2.36.1.255.ge46751e96f-goog In-Reply-To: <20220606150305.1883410-1-hsinyi@chromium.org> References: <20220606150305.1883410-1-hsinyi@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: gp17s5t8p97t9437d3xxfughekmfek87 Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=em8v3f6I; dmarc=pass (policy=none) header.from=chromium.org; spf=pass (imf09.hostedemail.com: domain of hsinyi@chromium.org designates 209.85.216.46 as permitted sender) smtp.mailfrom=hsinyi@chromium.org X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 05C93140016 X-HE-Tag: 1654527783-522058 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. - 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 Reported-by: Marek Szyprowski Reported-by: Andrew Morton --- v4->v5: - Handle short file cases reported by Marek and Matthew. - Fix checkpatch error reported by Andrew. v4: https://lore.kernel.org/lkml/20220601103922.1338320-4-hsinyi@chromium.org/ v3: https://lore.kernel.org/lkml/20220523065909.883444-4-hsinyi@chromium.org/ 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 | 124 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 123 insertions(+), 1 deletion(-) diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c index a8e495d8eb86..fbd096cd15f4 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 +496,128 @@ 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; + unsigned short 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; + int i, file_end = i_size_read(inode) >> msblk->block_log; + unsigned int max_pages = 1UL << shift; + + 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 (;;) { + pgoff_t index; + int res, bsize; + u64 block = 0; + unsigned int expected; + + nr_pages = __readahead_batch(ractl, pages, max_pages); + if (!nr_pages) + break; + + if (readahead_pos(ractl) >= i_size_read(inode)) + 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; + + if (nr_pages < max_pages) { + struct squashfs_cache_entry *buffer; + unsigned int block_mask = max_pages - 1; + int offset = pages[0]->index - (pages[0]->index & ~block_mask); + + buffer = squashfs_get_datablock(inode->i_sb, block, + bsize); + if (buffer->error) { + squashfs_cache_put(buffer); + goto skip_pages; + } + + expected -= offset * PAGE_SIZE; + for (i = 0; i < nr_pages && expected > 0; i++, + expected -= PAGE_SIZE, offset++) { + int avail = min_t(int, expected, PAGE_SIZE); + + squashfs_fill_page(pages[i], buffer, + offset * PAGE_SIZE, avail); + unlock_page(pages[i]); + } + + squashfs_cache_put(buffer); + continue; + } + + res = squashfs_read_data(inode->i_sb, block, bsize, NULL, + actor); + + if (res == expected) { + int bytes; + + /* Last page may have trailing bytes not filled */ + bytes = res % PAGE_SIZE; + if (bytes) { + void *pageaddr; + + pageaddr = kmap_atomic(pages[nr_pages - 1]); + memset(pageaddr + bytes, 0, PAGE_SIZE - bytes); + kunmap_atomic(pageaddr); + } + + for (i = 0; i < nr_pages; i++) { + flush_dcache_page(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 }; -- 2.36.1.255.ge46751e96f-goog