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 0353BC43334 for ; Tue, 7 Jun 2022 03:59:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 35C116B0072; Mon, 6 Jun 2022 23:59:36 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 30C686B0073; Mon, 6 Jun 2022 23:59:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1D2DA6B0074; Mon, 6 Jun 2022 23:59:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 0BF006B0072 for ; Mon, 6 Jun 2022 23:59:36 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id D67063316C for ; Tue, 7 Jun 2022 03:59:35 +0000 (UTC) X-FDA: 79550085510.26.219A404 Received: from p3plwbeout26-02.prod.phx3.secureserver.net (p3plsmtp26-02-2.prod.phx3.secureserver.net [216.69.139.26]) by imf05.hostedemail.com (Postfix) with ESMTP id C60EC10000E for ; Tue, 7 Jun 2022 03:58:54 +0000 (UTC) Received: from mailex.mailcore.me ([94.136.40.143]) by :WBEOUT: with ESMTP id yQNPnGVBBFTy7yQNQnzzjb; Mon, 06 Jun 2022 20:59:32 -0700 X-CMAE-Analysis: v=2.4 cv=ZYzYiuZA c=1 sm=1 tr=0 ts=629ecd24 a=EhJYbXVJKsomWlz4CTV+qA==:117 a=84ok6UeoqCVsigPHarzEiQ==:17 a=ggZhUymU-5wA:10 a=IkcTkHD0fZMA:10 a=JPEYwPQDsx4A:10 a=JfrnYn6hAAAA:8 a=cm27Pg_UAAAA:8 a=FXvPX3liAAAA:8 a=t7CeM3EgAAAA:8 a=hD80L64hAAAA:8 a=Z4Rwk6OoAAAA:8 a=VwQbUJbxAAAA:8 a=5-cV24NVlsSd070NXMcA:9 a=QEXdDO2ut3YA:10 a=1CNFftbPRP8L7MoqJWF3:22 a=xmb-EsYY8bH0VWELuYED:22 a=UObqyxdv-6Yh2QiB9mM_:22 a=FdTzh2GWekK77mhwV6Dw:22 a=HkZW87K1Qel5hWWM3VKY:22 a=AjGcO6oz07-iQ99wixmX:22 X-SECURESERVER-ACCT: phillip@squashfs.org.uk X-SID: yQNPnGVBBFTy7 Received: from 82-69-79-175.dsl.in-addr.zen.co.uk ([82.69.79.175] helo=[192.168.178.33]) by smtp12.mailcore.me with esmtpa (Exim 4.94.2) (envelope-from ) id 1nyQNN-0002Hk-5Y; Tue, 07 Jun 2022 04:59:31 +0100 Message-ID: <81b1828d-37d3-5b05-410e-7e931d966ed8@squashfs.org.uk> Date: Tue, 7 Jun 2022 04:59:25 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v5 3/3] squashfs: implement readahead To: Hsin-Yi Wang , 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 References: <20220606150305.1883410-1-hsinyi@chromium.org> <20220606150305.1883410-4-hsinyi@chromium.org> From: Phillip Lougher In-Reply-To: <20220606150305.1883410-4-hsinyi@chromium.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Mailcore-Auth: 439999529 X-Mailcore-Domain: 1394945 X-123-reg-Authenticated: phillip@squashfs.org.uk X-Originating-IP: 82.69.79.175 X-CMAE-Envelope: MS4xfDqUV1DGBgRKpuGHdqyrbQtU+P6jA51hesNKS6BXm1TV6OxMGHNB1CzmEAHE8+tJopQQpjyNdZMbefpxd9+eUq09bdaN+r6ZdLXEUfZM+Z48qzUyeGX2 7fvu3elzLbxlHcsaf+jgC0NarvvqjYO36iVQ8KM+oraBC2IgxN4gzje011K9PPS8/TqtRRfP8GZPUPm3nb4QB6eVkgp4zDF0T7A= X-Stat-Signature: 1e65zcdwbicapg444ft5dqwrgk747zjs X-Rspam-User: Authentication-Results: imf05.hostedemail.com; dkim=none; spf=none (imf05.hostedemail.com: domain of phillip@squashfs.org.uk has no SPF policy when checking 216.69.139.26) smtp.mailfrom=phillip@squashfs.org.uk; dmarc=none X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: C60EC10000E X-HE-Tag: 1654574334-359906 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: On 06/06/2022 16:03, Hsin-Yi Wang wrote: > 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. Thanks for the updated patch. I'm currently testing and reviewing the patch, and this may take a couple of days. Phillip > > 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 > };