linux-kernel - [PATCH 7/8] erofs: adapt folios for z_erofs

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: <20230817082813.81180-7-hsiangkao@linux.alibaba.com>
Date:   Thu, 17 Aug 2023 16:28:12 +0800
From:   Gao Xiang <hsiangkao@...ux.alibaba.com>
To:     linux-erofs@...ts.ozlabs.org
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Gao Xiang <hsiangkao@...ux.alibaba.com>
Subject: [PATCH 7/8] erofs: adapt folios for z_erofs_readahead()

It's a straight-forward conversion except that readahead_folio()
will do folio_put() in advance but it doesn't matter since folios
are still locked.

As before, since file-backed folios (pages for now) are locked, so
we could temporarily use folio->private as an internal counter to
indicate split parts of each folio for the corresponding pclusters
to decompress.

When such counter becomes zero, the folio will be finally unlocked
(see compress.h and z_erofs_onlinepage_endio()).

Signed-off-by: Gao Xiang <hsiangkao@...ux.alibaba.com>
---
 fs/erofs/zdata.c | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index c28945532a02..79cadb88e8bf 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1852,37 +1852,35 @@ static void z_erofs_readahead(struct readahead_control *rac)
 	struct inode *const inode = rac->mapping->host;
 	struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
 	struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
-	struct page *head = NULL, *page;
-	unsigned int nr_pages;
+	struct folio *head = NULL, *folio;
+	unsigned int nr_folios;
+	int err;
 
 	f.headoffset = readahead_pos(rac);
 
 	z_erofs_pcluster_readmore(&f, rac, true);
-	nr_pages = readahead_count(rac);
-	trace_erofs_readpages(inode, readahead_index(rac), nr_pages, false);
+	nr_folios = readahead_count(rac);
+	trace_erofs_readpages(inode, readahead_index(rac), nr_folios, false);
 
-	while ((page = readahead_page(rac))) {
-		set_page_private(page, (unsigned long)head);
-		head = page;
+	while ((folio = readahead_folio(rac))) {
+		folio->private = head;
+		head = folio;
 	}
 
+	/* traverse in reverse order for best metadata I/O performance */
 	while (head) {
-		struct page *page = head;
-		int err;
-
-		/* traversal in reverse order */
-		head = (void *)page_private(page);
+		folio = head;
+		head = folio_get_private(folio);
 
-		err = z_erofs_do_read_page(&f, page);
+		err = z_erofs_do_read_page(&f, &folio->page);
 		if (err && err != -EINTR)
-			erofs_err(inode->i_sb, "readahead error %d @ %lu of nid %llu",
-				  err, page->index, EROFS_I(inode)->nid);
-		put_page(page);
+			erofs_err(inode->i_sb, "readahead error at folio %lu @ nid %llu",
+				  folio->index, EROFS_I(inode)->nid);
 	}
 	z_erofs_pcluster_readmore(&f, rac, false);
 	z_erofs_pcluster_end(&f);
 
-	z_erofs_runqueue(&f, z_erofs_is_sync_decompress(sbi, nr_pages), true);
+	z_erofs_runqueue(&f, z_erofs_is_sync_decompress(sbi, nr_folios), true);
 	erofs_put_metabuf(&f.map.buf);
 	erofs_release_pages(&f.pagepool);
 }
-- 
2.24.4