ext4: fix potential error in ext4_do_update_inode

mainline inclusion
from mainline-v5.12-rc4
commit 7d8bd3c7
category: bugfix
bugzilla: 51135
CVE: NA

-----------------------------------------------

If set_large_file = 1 and errors occur in ext4_handle_dirty_metadata(),
the error code will be overridden, go to out_brelse to avoid this
situation.
Signed-off-by: NShijie Luo <luoshijie1@huawei.com>
Link: https://lore.kernel.org/r/20210312065051.36314-1-luoshijie1@huawei.com
Cc: stable@kernel.org
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NZhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: Nzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NCheng Jian <cj.chengjian@huawei.com>

fs/ext4/inode.c

@@ -5282,7 +5282,7 @@ static int ext4_do_update_inode(handle_t *handle,
 	struct ext4_inode_info *ei = EXT4_I(inode);
 	struct buffer_head *bh = iloc->bh;
 	struct super_block *sb = inode->i_sb;
-	int err = 0, rc, block;
+	int err = 0, block;
 	int need_datasync = 0, set_large_file = 0;
 	uid_t i_uid;
 	gid_t i_gid;
@@ -5394,9 +5394,9 @@ static int ext4_do_update_inode(handle_t *handle,
 					      bh->b_data);
 
 	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
-	rc = ext4_handle_dirty_metadata(handle, NULL, bh);
-	if (!err)
-		err = rc;
+	err = ext4_handle_dirty_metadata(handle, NULL, bh);
+	if (err)
+		goto out_brelse;
 	ext4_clear_inode_state(inode, EXT4_STATE_NEW);
 	if (set_large_file) {
 		BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get write access");