Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
To:     <yi.zhang@huawei.com>, <tytso@mit.edu>, <jack@suse.cz>,
        <linux-ext4@vger.kernel.org>
CC:     <adilger.kernel@dilger.ca>
Subject: [PATCH v2] ext4: Fix bdev write error check failed when mount fs with ro
Date:   Thu, 24 Sep 2020 21:01:42 -0400
Message-ID: <20200925010142.3711176-1-zhangxiaoxu5@huawei.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 7BIT
Content-Type:   text/plain; charset=US-ASCII
Precedence: bulk

If some errors has occurred on the device, and the orphan list not empty,
then mount the device with 'ro', the bdev write error check will failed:
  ext4_check_bdev_write_error:193: comm mount: Error while async write back metadata

Since the sbi->s_bdev_wb_err wouldn't be initialized when mount file system
with 'ro', when clean up the orphan list and access the iloc buffer, bdev
write error check will failed.

So we should always initialize the sbi->s_bdev_wb_err even if mount the
file system with 'ro'.

Fixes: bc71726c7257 ("ext4: abort the filesystem if failed to async write metadata buffer")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
---
 fs/ext4/super.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ea425b49b345..0303e6e17190 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4814,9 +4814,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	 * used to detect the metadata async write error.
 	 */
 	spin_lock_init(&sbi->s_bdev_wb_lock);
-	if (!sb_rdonly(sb))
-		errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
-					 &sbi->s_bdev_wb_err);
+	errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
+				 &sbi->s_bdev_wb_err);
 	sb->s_bdev->bd_super = sb;
 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
 	ext4_orphan_cleanup(sb, es);
@@ -5707,14 +5706,6 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 				goto restore_opts;
 			}
 
-			/*
-			 * Update the original bdev mapping's wb_err value
-			 * which could be used to detect the metadata async
-			 * write error.
-			 */
-			errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
-						 &sbi->s_bdev_wb_err);
-
 			/*
 			 * Mounting a RDONLY partition read-write, so reread
 			 * and store the current valid flag.  (It may have
-- 
2.25.4