RE: [PATCH RESEND v6 2/9] dax: Introduce holder for dax_device

From: "ruansy.fnst@fujitsu.com" <ruansy.fnst@fujitsu.com>
To: Jane Chu <jane.chu@oracle.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-xfs@vger.kernel.org" <linux-xfs@vger.kernel.org>,
	"nvdimm@lists.linux.dev" <nvdimm@lists.linux.dev>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"dm-devel@redhat.com" <dm-devel@redhat.com>
Cc: "djwong@kernel.org" <djwong@kernel.org>,
	"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
	"david@fromorbit.com" <david@fromorbit.com>,
	"hch@lst.de" <hch@lst.de>, "agk@redhat.com" <agk@redhat.com>,
	"snitzer@redhat.com" <snitzer@redhat.com>
Subject: RE: [PATCH RESEND v6 2/9] dax: Introduce holder for dax_device
Date: Tue, 17 Aug 2021 01:45:28 +0000	[thread overview]
Message-ID: <OSBPR01MB292042C10A7AA95CB6862F08F4FE9@OSBPR01MB2920.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <e844fc54-113f-239d-da23-fa140aeea9d7@oracle.com>

> -----Original Message-----
> From: Jane Chu <jane.chu@oracle.com>
> Subject: Re: [PATCH RESEND v6 2/9] dax: Introduce holder for dax_device
> 
> 
> On 7/30/2021 3:01 AM, Shiyang Ruan wrote:
> > --- a/drivers/dax/super.c
> > +++ b/drivers/dax/super.c
> > @@ -214,6 +214,8 @@ enum dax_device_flags {
> >    * @cdev: optional character interface for "device dax"
> >    * @host: optional name for lookups where the device path is not available
> >    * @private: dax driver private data
> > + * @holder_rwsem: prevent unregistration while holder_ops is in progress
> > + * @holder_data: holder of a dax_device: could be filesystem or mapped
> device
> >    * @flags: state and boolean properties
> 
> Perhaps add two documentary lines for @ops and @holder_ops?

OK. I'll add them in next version.

--
Thanks,
Ruan.

> >    */
> >   struct dax_device {
> > @@ -222,8 +224,11 @@ struct dax_device {
> >   	struct cdev cdev;
> >   	const char *host;
> >   	void *private;
> > +	struct rw_semaphore holder_rwsem;
> > +	void *holder_data;
> >   	unsigned long flags;
> >   	const struct dax_operations *ops;
> > +	const struct dax_holder_operations *holder_ops;
> >   };
> 
> thanks,
> -jane