linux-kernel - [PATCH v11 06/25] mm: Use readahead

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200414150233.24495-7-willy@infradead.org>
Date:   Tue, 14 Apr 2020 08:02:14 -0700
From:   Matthew Wilcox <willy@...radead.org>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, linux-btrfs@...r.kernel.org,
        linux-erofs@...ts.ozlabs.org, linux-ext4@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net, cluster-devel@...hat.com,
        ocfs2-devel@....oracle.com, linux-xfs@...r.kernel.org,
        John Hubbard <jhubbard@...dia.com>,
        Christoph Hellwig <hch@....de>,
        William Kucharski <william.kucharski@...cle.com>
Subject: [PATCH v11 06/25] mm: Use readahead_control to pass arguments

From: "Matthew Wilcox (Oracle)" <willy@...radead.org>

In this patch, only between __do_page_cache_readahead() and read_pages(),
but it will be extended in upcoming patches.  The read_pages() function
becomes aops centric, as this makes the most sense by the end of the
patchset.

Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
Reviewed-by: John Hubbard <jhubbard@...dia.com>
Reviewed-by: Christoph Hellwig <hch@....de>
Reviewed-by: William Kucharski <william.kucharski@...cle.com>
---
 mm/readahead.c | 33 +++++++++++++++++++--------------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/mm/readahead.c b/mm/readahead.c
index 9fcd4e32b62d..9d9aa4ffc7d4 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -113,29 +113,32 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages,
 
 EXPORT_SYMBOL(read_cache_pages);
 
-static void read_pages(struct address_space *mapping, struct file *filp,
-		struct list_head *pages, unsigned int nr_pages, gfp_t gfp)
+static void read_pages(struct readahead_control *rac, struct list_head *pages,
+		gfp_t gfp)
 {
+	const struct address_space_operations *aops = rac->mapping->a_ops;
 	struct blk_plug plug;
 	unsigned page_idx;
 
-	if (!nr_pages)
+	if (!readahead_count(rac))
 		return;
 
 	blk_start_plug(&plug);
 
-	if (mapping->a_ops->readpages) {
-		mapping->a_ops->readpages(filp, mapping, pages, nr_pages);
+	if (aops->readpages) {
+		aops->readpages(rac->file, rac->mapping, pages,
+				readahead_count(rac));
 		/* Clean up the remaining pages */
 		put_pages_list(pages);
 		goto out;
 	}
 
-	for (page_idx = 0; page_idx < nr_pages; page_idx++) {
+	for (page_idx = 0; page_idx < readahead_count(rac); page_idx++) {
 		struct page *page = lru_to_page(pages);
 		list_del(&page->lru);
-		if (!add_to_page_cache_lru(page, mapping, page->index, gfp))
-			mapping->a_ops->readpage(filp, page);
+		if (!add_to_page_cache_lru(page, rac->mapping, page->index,
+				gfp))
+			aops->readpage(rac->file, page);
 		put_page(page);
 	}
 
@@ -143,6 +146,7 @@ static void read_pages(struct address_space *mapping, struct file *filp,
 	blk_finish_plug(&plug);
 
 	BUG_ON(!list_empty(pages));
+	rac->_nr_pages = 0;
 }
 
 /*
@@ -160,9 +164,12 @@ void __do_page_cache_readahead(struct address_space *mapping,
 	unsigned long end_index;	/* The last page we want to read */
 	LIST_HEAD(page_pool);
 	int page_idx;
-	unsigned int nr_pages = 0;
 	loff_t isize = i_size_read(inode);
 	gfp_t gfp_mask = readahead_gfp_mask(mapping);
+	struct readahead_control rac = {
+		.mapping = mapping,
+		.file = filp,
+	};
 
 	if (isize == 0)
 		return;
@@ -185,9 +192,7 @@ void __do_page_cache_readahead(struct address_space *mapping,
 			 * contiguous pages before continuing with the next
 			 * batch.
 			 */
-			read_pages(mapping, filp, &page_pool, nr_pages,
-						gfp_mask);
-			nr_pages = 0;
+			read_pages(&rac, &page_pool, gfp_mask);
 			continue;
 		}
 
@@ -198,7 +203,7 @@ void __do_page_cache_readahead(struct address_space *mapping,
 		list_add(&page->lru, &page_pool);
 		if (page_idx == nr_to_read - lookahead_size)
 			SetPageReadahead(page);
-		nr_pages++;
+		rac._nr_pages++;
 	}
 
 	/*
@@ -206,7 +211,7 @@ void __do_page_cache_readahead(struct address_space *mapping,
 	 * uptodate then the caller will launch readpage again, and
 	 * will then handle the error.
 	 */
-	read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask);
+	read_pages(&rac, &page_pool, gfp_mask);
 }
 
 /*
-- 
2.25.1