RE: Regression caused by using node_to_bdi()

From: Zhao Lei <zhaolei@cn.fujitsu.com>
To: "'Boaz Harrosh'" <boaz@plexistor.com>,
	"'Christoph Hellwig'" <hch@lst.de>
Cc: <linux-fsdevel@vger.kernel.org>, "'Jan Kara'" <jack@suse.cz>,
	"'Jens Axboe'" <axboe@fb.com>,
	"'LKML'" <linux-kernel@vger.kernel.org>
Subject: RE: Regression caused by using node_to_bdi()
Date: Tue, 14 Apr 2015 20:14:48 +0800	[thread overview]
Message-ID: <040701d076ac$9a6dbd40$cf4937c0$@cn.fujitsu.com> (raw)
In-Reply-To: <552BB70A.3070603@plexistor.com>

Hi, Boaz

> -----Original Message-----
> From: Boaz Harrosh [mailto:boaz@plexistor.com]
> Sent: Monday, April 13, 2015 8:31 PM
> To: Zhao Lei; 'Boaz Harrosh'; 'Christoph Hellwig'
> Cc: linux-fsdevel@vger.kernel.org; 'Jan Kara'; 'Jens Axboe'; 'LKML'
> Subject: Re: Regression caused by using node_to_bdi()
> 
> On 04/13/2015 01:22 PM, Zhao Lei wrote:
> <>
> > A new bad news:
> > This patch make filesystem unstable.
> >
> 
> Rrrr yes sorry Lei. Why this boots my systems is not clear this is not what I
> intended to write.
> 
> Here is what I meant to write (replacing the old one):

Thanks for v2 patch.
But is still halt the test machine with same error message in boot.

I applied the patch on v4.0-rc1, not just after the patch of
introduce node_to_bdi() in this mail.

Is way of inode->i_sb->s_bdi changed after we move to node_to_bdi()?

Thanks
Zhaolei

> ----
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 32a8bbd..e0375e1
> 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -78,7 +78,7 @@ int writeback_in_progress(struct backing_dev_info
> *bdi)  }  EXPORT_SYMBOL(writeback_in_progress);
> 
> -struct backing_dev_info *inode_to_bdi(struct inode *inode)
> +struct backing_dev_info *__inode_to_bdi(struct inode *inode)
>  {
>  	struct super_block *sb;
> 
> @@ -92,7 +92,7 @@ struct backing_dev_info *inode_to_bdi(struct inode
> *inode)  #endif
>  	return sb->s_bdi;
>  }
> -EXPORT_SYMBOL_GPL(inode_to_bdi);
> +EXPORT_SYMBOL_GPL(__inode_to_bdi);
> 
>  static inline struct inode *wb_inode(struct list_head *head)  { diff --git
> a/include/linux/backing-dev.h b/include/linux/backing-dev.h index
> aff923a..53d97cd 100644
> --- a/include/linux/backing-dev.h
> +++ b/include/linux/backing-dev.h
> @@ -107,7 +107,16 @@ struct backing_dev_info {  #endif  };
> 
> -struct backing_dev_info *inode_to_bdi(struct inode *inode);
> +struct backing_dev_info *__inode_to_bdi(struct inode *inode);
> +
> +static inline
> +struct backing_dev_info *inode_to_bdi(struct inode *inode) {
> +	if (!inode || !inode->i_sb || !inode->i_sb->s_bdi)
> +		return __inode_to_bdi(inode);
> +
> +	return inode->i_sb->s_bdi;	
> +}
> 
>  int __must_check bdi_init(struct backing_dev_info *bdi);  void
> bdi_destroy(struct backing_dev_info *bdi);
> 