[PATCH] f2fs: fix a redundant call to f2fs_balance_fs if an error occurs

From: Colin King <colin.king@canonical.com>
To: Jaegeuk Kim <jaegeuk@kernel.org>, Chao Yu <chao@kernel.org>,
	linux-f2fs-devel@lists.sourceforge.net
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] f2fs: fix a redundant call to f2fs_balance_fs if an error occurs
Date: Thu,  4 Mar 2021 09:21:18 +0000	[thread overview]
Message-ID: <20210304092118.2279879-1-colin.king@canonical.com> (raw)

From: Colin Ian King <colin.king@canonical.com>

The  uninitialized variable dn.node_changed does not get set when a
call to f2fs_get_node_page fails.  This uninitialized value gets used
in the call to f2fs_balance_fs() that may or not may not balances
dirty node and dentry pages depending on the uninitialized state of
the variable. Fix this by only calling f2fs_balance_fs if err is
not set.

Thanks to Jaegeuk Kim for suggesting an appropriate fix.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 2a3407607028 ("f2fs: call f2fs_balance_fs only when node was changed")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 fs/f2fs/inline.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 993caefcd2bb..92652ca7a7c8 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -219,7 +219,8 @@ int f2fs_convert_inline_inode(struct inode *inode)
 
 	f2fs_put_page(page, 1);
 
-	f2fs_balance_fs(sbi, dn.node_changed);
+	if (!err)
+		f2fs_balance_fs(sbi, dn.node_changed);
 
 	return err;
 }
-- 
2.30.0

