On 2021/10/19 21:49, Jan Kara wrote:

On Tue 19-10-21 20:39:31, Ye Bin wrote:

quoted

This patch is according to Jan Kara's suggestion:
I guess I would just get rid of sb_getblk() in read_mmp_block() and always
expect valid bh passed. The only place that passes NULL bh after this
patch is one case in ext4_multi_mount_protect() and that can call
sb_getblk() on its own. That way we can also simplify read_mmp_block()
prototype to:

static int read_mmp_block(struct super_block *sb, struct buffer_head *bh);

Signed-off-by: Ye Bin <redacted>
Reviewed-by: Jan Kara <jack@suse.cz>

...

quoted

@@ -289,7 +279,11 @@ int ext4_multi_mount_protect(struct super_block *sb,
  		goto failed;
  	}
  
-	retval = read_mmp_block(sb, &bh, mmp_block);
+	bh = sb_getblk(sb, mmp_block);
+	if (bh)

	^^^^^^

!bh here, please.

Sorry，it's my fault. I will fix it and test  this patch set base on 
linux mainline.

								Honza