From: Vasily Averin <vvs@virtuozzo.com>
Subject: [PATCH v2 03/11] ext4 resize: brelse() cleanup in
 add_new_gdb_meta_bg()
To: linux-ext4@vger.kernel.org, Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>,
        linux-kernel@vger.kernel.org,
        Yongqiang Yang <xiaoqiangnk@gmail.com>,
        Yongqiang Yang <yangyongqiang01@baidu.com>
References: <cover.1540935522.git.vvs@virtuozzo.com>
Message-ID: <34d94824-834c-fb72-2f93-01e9036e9b38@virtuozzo.com>
Date: Wed, 31 Oct 2018 00:57:55 +0300
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In-Reply-To: <cover.1540935522.git.vvs@virtuozzo.com>
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Sender: linux-ext4-owner@vger.kernel.org

gdb_bh must be released in case of errors before update of s_group_desc
but it must not be released after update of group descriptors
because in this case bh can be used later.

Fixes 01f795f9e0d6 ("ext4: add online resizing support for meta_bg ...") # 3.7

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
---
 fs/ext4/resize.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 0a4dc6217e78..7131f35b62d9 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -922,6 +922,7 @@ static int add_new_gdb_meta_bg(struct super_block *sb,
 				     sizeof(struct buffer_head *),
 				     GFP_NOFS);
 	if (!n_group_desc) {
+		brelse(gdb_bh);
 		err = -ENOMEM;
 		ext4_warning(sb, "not enough memory for %lu groups",
 			     gdb_num + 1);
@@ -937,8 +938,6 @@ static int add_new_gdb_meta_bg(struct super_block *sb,
 	kvfree(o_group_desc);
 	BUFFER_TRACE(gdb_bh, "get_write_access");
 	err = ext4_journal_get_write_access(handle, gdb_bh);
-	if (unlikely(err))
-		brelse(gdb_bh);
 	return err;
 }
 
-- 
2.17.1