linux-kernel - [PATCH] 9p: set page uptodate when required in write

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Date:   Mon, 10 Apr 2017 18:46:51 +0000
From:   alexander.levin@...izon.com
To:     "ericvh@...il.com" <ericvh@...il.com>,
        "rminnich@...dia.gov" <rminnich@...dia.gov>,
        "lucho@...kov.net" <lucho@...kov.net>
Cc:     "v9fs-developer@...ts.sourceforge.net" 
        <v9fs-developer@...ts.sourceforge.net>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "jack@...e.com" <jack@...e.com>,
        "viro@...iv.linux.org.uk" <viro@...iv.linux.org.uk>,
        alexander.levin@...izon.com
Subject: [PATCH] 9p: set page uptodate when required in write_end()

From: Alexander Levin <alexander.levin@...izon.com>

Commit 77469c3f570 prevented setting the page as uptodate when we wrote the
right amount of data, fix that.

Fixes: 77469c3f570 ("9p: saner ->write_end() on failing copy into non-uptodate page")
Reviewed-by: Jan Kara <jack@...e.com>
Signed-off-by: Alexander Levin <alexander.levin@...izon.com>
---
 fs/9p/vfs_addr.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index adaf6f6..e1cbdfd 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -310,9 +310,13 @@ static int v9fs_write_end(struct file *filp, struct address_space *mapping,
 
 	p9_debug(P9_DEBUG_VFS, "filp %p, mapping %p\n", filp, mapping);
 
-	if (unlikely(copied < len && !PageUptodate(page))) {
-		copied = 0;
-		goto out;
+	if (!PageUptodate(page)) {
+		if (unlikely(copied < len)) {
+			copied = 0;
+			goto out;
+		} else if (len == PAGE_SIZE) {
+			SetPageUptodate(page);
+		}
 	}
 	/*
 	 * No need to use i_size_read() here, the i_size
-- 
2.7.4