Re: [PATCH v2 1/5] ext4: Fix reusing stale buffer heads from last failed mounting

[Zhihao Cheng]

在 2023/3/14 19:33, Jan Kara 写道:
Hi Jan,

> > @@ -1271,14 +1277,8 @@ static void ext4_put_super(struct super_block *sb)
> >   
> >   	sync_blockdev(sb->s_bdev);
> >   	invalidate_bdev(sb->s_bdev);

For journal in the inode case, journal bhs come from block device, which 
means buffers will be dropped after this line 
'invalidate_bdev(sb->s_bdev)' being executed.

> > -	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
> > -		/*
> > -		 * Invalidate the journal device's buffers.  We don't want them
> > -		 * floating about in memory - the physical journal device may
> > -		 * hotswapped, and it breaks the `ro-after' testing code.
> > -		 */
> > +	if (sbi->s_journal_bdev) {
> >   		sync_blockdev(sbi->s_journal_bdev);
> > -		invalidate_bdev(sbi->s_journal_bdev);
> >   		ext4_blkdev_remove(sbi);
> >   	}
>  > Hum, but this will invalidate bhs only if journal is stored on a block
> device. If journal is in the inode (the common case), we won't invalidate
> anything (sbi->s_journal_bdev is NULL) and the same problem can happen?