From patchwork Mon Mar 23 20:22:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11453947 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0728E1668 for ; Mon, 23 Mar 2020 20:25:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D16D920753 for ; Mon, 23 Mar 2020 20:25:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TPybKGkT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727186AbgCWUXE (ORCPT ); Mon, 23 Mar 2020 16:23:04 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:36808 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725861AbgCWUXC (ORCPT ); Mon, 23 Mar 2020 16:23:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=DcQHOlgwNqeEPN3fiAW/rNxfySxuJVhOd+sF/+JeQ6E=; b=TPybKGkTlLYjObv6dPcawhPHLm RCByjj/hE7TkPru+cXnpw/Ez0mfGPUyiOwAzcH9xWgftIj9QABRpbFkbBMXgsaQjG959xgTmnBfW0 CXLy7eljwHojUJRAA9lMX//CykIsqgQVVHaP8SKOxFCJmVXoLE4EaStMc1H3zvk+9NoSGNaZSWkng /4ntS/huqrVKoEi51RWPz0U1a0bvMTmCsm/ZDVgddtOV5ZnRpXj/3XB332HzsZ6L9tCe1SBvyEPrY ZpvUzn8SNbHPQKWaU52mPoMTbQrCCv9cvb4r8ogKVeGD9DfAQgsS9XaDdjNbrEPbX6lMgCyE1FuSb 0MbqwdWw==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jGTbC-0003WB-7j; Mon, 23 Mar 2020 20:23:02 +0000 From: Matthew Wilcox To: Andrew Morton Cc: "Matthew Wilcox (Oracle)" , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, ocfs2-devel@oss.oracle.com, linux-xfs@vger.kernel.org, Christoph Hellwig , "Darrick J . Wong" , William Kucharski Subject: [PATCH v10 25/25] iomap: Convert from readpages to readahead Date: Mon, 23 Mar 2020 13:22:59 -0700 Message-Id: <20200323202259.13363-26-willy@infradead.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200323202259.13363-1-willy@infradead.org> References: <20200323202259.13363-1-willy@infradead.org> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: "Matthew Wilcox (Oracle)" Use the new readahead operation in iomap. Convert XFS and ZoneFS to use it. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Reviewed-by: William Kucharski --- fs/iomap/buffered-io.c | 90 +++++++++++++++--------------------------- fs/iomap/trace.h | 2 +- fs/xfs/xfs_aops.c | 13 +++--- fs/zonefs/super.c | 7 ++-- include/linux/iomap.h | 3 +- 5 files changed, 41 insertions(+), 74 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index e7928678564f..1734d79acc0a 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -214,9 +214,8 @@ iomap_read_end_io(struct bio *bio) struct iomap_readpage_ctx { struct page *cur_page; bool cur_page_in_bio; - bool is_readahead; struct bio *bio; - struct list_head *pages; + struct readahead_control *rac; }; static void @@ -307,11 +306,11 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, if (ctx->bio) submit_bio(ctx->bio); - if (ctx->is_readahead) /* same as readahead_gfp_mask */ + if (ctx->rac) /* same as readahead_gfp_mask */ gfp |= __GFP_NORETRY | __GFP_NOWARN; ctx->bio = bio_alloc(gfp, min(BIO_MAX_PAGES, nr_vecs)); ctx->bio->bi_opf = REQ_OP_READ; - if (ctx->is_readahead) + if (ctx->rac) ctx->bio->bi_opf |= REQ_RAHEAD; ctx->bio->bi_iter.bi_sector = sector; bio_set_dev(ctx->bio, iomap->bdev); @@ -367,36 +366,8 @@ iomap_readpage(struct page *page, const struct iomap_ops *ops) } EXPORT_SYMBOL_GPL(iomap_readpage); -static struct page * -iomap_next_page(struct inode *inode, struct list_head *pages, loff_t pos, - loff_t length, loff_t *done) -{ - while (!list_empty(pages)) { - struct page *page = lru_to_page(pages); - - if (page_offset(page) >= (u64)pos + length) - break; - - list_del(&page->lru); - if (!add_to_page_cache_lru(page, inode->i_mapping, page->index, - GFP_NOFS)) - return page; - - /* - * If we already have a page in the page cache at index we are - * done. Upper layers don't care if it is uptodate after the - * readpages call itself as every page gets checked again once - * actually needed. - */ - *done += PAGE_SIZE; - put_page(page); - } - - return NULL; -} - static loff_t -iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length, +iomap_readahead_actor(struct inode *inode, loff_t pos, loff_t length, void *data, struct iomap *iomap, struct iomap *srcmap) { struct iomap_readpage_ctx *ctx = data; @@ -410,10 +381,7 @@ iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length, ctx->cur_page = NULL; } if (!ctx->cur_page) { - ctx->cur_page = iomap_next_page(inode, ctx->pages, - pos, length, &done); - if (!ctx->cur_page) - break; + ctx->cur_page = readahead_page(ctx->rac); ctx->cur_page_in_bio = false; } ret = iomap_readpage_actor(inode, pos + done, length - done, @@ -423,32 +391,43 @@ iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length, return done; } -int -iomap_readpages(struct address_space *mapping, struct list_head *pages, - unsigned nr_pages, const struct iomap_ops *ops) +/** + * iomap_readahead - Attempt to read pages from a file. + * @rac: Describes the pages to be read. + * @ops: The operations vector for the filesystem. + * + * This function is for filesystems to call to implement their readahead + * address_space operation. + * + * Context: The @ops callbacks may submit I/O (eg to read the addresses of + * blocks from disc), and may wait for it. The caller may be trying to + * access a different page, and so sleeping excessively should be avoided. + * It may allocate memory, but should avoid costly allocations. This + * function is called with memalloc_nofs set, so allocations will not cause + * the filesystem to be reentered. + */ +void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops) { + struct inode *inode = rac->mapping->host; + loff_t pos = readahead_pos(rac); + loff_t length = readahead_length(rac); struct iomap_readpage_ctx ctx = { - .pages = pages, - .is_readahead = true, + .rac = rac, }; - loff_t pos = page_offset(list_entry(pages->prev, struct page, lru)); - loff_t last = page_offset(list_entry(pages->next, struct page, lru)); - loff_t length = last - pos + PAGE_SIZE, ret = 0; - trace_iomap_readpages(mapping->host, nr_pages); + trace_iomap_readahead(inode, readahead_count(rac)); while (length > 0) { - ret = iomap_apply(mapping->host, pos, length, 0, ops, - &ctx, iomap_readpages_actor); + loff_t ret = iomap_apply(inode, pos, length, 0, ops, + &ctx, iomap_readahead_actor); if (ret <= 0) { WARN_ON_ONCE(ret == 0); - goto done; + break; } pos += ret; length -= ret; } - ret = 0; -done: + if (ctx.bio) submit_bio(ctx.bio); if (ctx.cur_page) { @@ -456,15 +435,8 @@ iomap_readpages(struct address_space *mapping, struct list_head *pages, unlock_page(ctx.cur_page); put_page(ctx.cur_page); } - - /* - * Check that we didn't lose a page due to the arcance calling - * conventions.. - */ - WARN_ON_ONCE(!ret && !list_empty(ctx.pages)); - return ret; } -EXPORT_SYMBOL_GPL(iomap_readpages); +EXPORT_SYMBOL_GPL(iomap_readahead); /* * iomap_is_partially_uptodate checks whether blocks within a page are diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h index 4df19c66f597..5693a39d52fb 100644 --- a/fs/iomap/trace.h +++ b/fs/iomap/trace.h @@ -39,7 +39,7 @@ DEFINE_EVENT(iomap_readpage_class, name, \ TP_PROTO(struct inode *inode, int nr_pages), \ TP_ARGS(inode, nr_pages)) DEFINE_READPAGE_EVENT(iomap_readpage); -DEFINE_READPAGE_EVENT(iomap_readpages); +DEFINE_READPAGE_EVENT(iomap_readahead); DECLARE_EVENT_CLASS(iomap_range_class, TP_PROTO(struct inode *inode, unsigned long off, unsigned int len), diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 9d9cebf18726..1fd4fb7a607c 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -621,14 +621,11 @@ xfs_vm_readpage( return iomap_readpage(page, &xfs_read_iomap_ops); } -STATIC int -xfs_vm_readpages( - struct file *unused, - struct address_space *mapping, - struct list_head *pages, - unsigned nr_pages) +STATIC void +xfs_vm_readahead( + struct readahead_control *rac) { - return iomap_readpages(mapping, pages, nr_pages, &xfs_read_iomap_ops); + iomap_readahead(rac, &xfs_read_iomap_ops); } static int @@ -644,7 +641,7 @@ xfs_iomap_swapfile_activate( const struct address_space_operations xfs_address_space_operations = { .readpage = xfs_vm_readpage, - .readpages = xfs_vm_readpages, + .readahead = xfs_vm_readahead, .writepage = xfs_vm_writepage, .writepages = xfs_vm_writepages, .set_page_dirty = iomap_set_page_dirty, diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c index 69aee3dfb660..546aee6283c8 100644 --- a/fs/zonefs/super.c +++ b/fs/zonefs/super.c @@ -78,10 +78,9 @@ static int zonefs_readpage(struct file *unused, struct page *page) return iomap_readpage(page, &zonefs_iomap_ops); } -static int zonefs_readpages(struct file *unused, struct address_space *mapping, - struct list_head *pages, unsigned int nr_pages) +static void zonefs_readahead(struct readahead_control *rac) { - return iomap_readpages(mapping, pages, nr_pages, &zonefs_iomap_ops); + iomap_readahead(rac, &zonefs_iomap_ops); } /* @@ -128,7 +127,7 @@ static int zonefs_writepages(struct address_space *mapping, static const struct address_space_operations zonefs_file_aops = { .readpage = zonefs_readpage, - .readpages = zonefs_readpages, + .readahead = zonefs_readahead, .writepage = zonefs_writepage, .writepages = zonefs_writepages, .set_page_dirty = iomap_set_page_dirty, diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 8b09463dae0d..bc20bd04c2a2 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -155,8 +155,7 @@ loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length, ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, const struct iomap_ops *ops); int iomap_readpage(struct page *page, const struct iomap_ops *ops); -int iomap_readpages(struct address_space *mapping, struct list_head *pages, - unsigned nr_pages, const struct iomap_ops *ops); +void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops); int iomap_set_page_dirty(struct page *page); int iomap_is_partially_uptodate(struct page *page, unsigned long from, unsigned long count);