Re: [dm-devel] [RFC] DM_TARGET_CTL: ioctl interface

[Mike Christie <mikenc us ibm com>]

Alasdair G Kergon wrote:
> On Tue, May 25, 2004 at 01:55:23PM +0100, Alasdair G Kergon wrote:
>
> > On Mon, May 24, 2004 at 06:00:19PM -0700, Mike Christie wrote:
> >
> > > Is there any way
> > > I could pass in such a thing when my target is created, so that way dm 
> > > multipath
> > > would not have any type of command format functions/modules or definitions
> > > (it could just be passed in and built like the sg io code).
> >
> > We've been talking about a new dm ioctl for passing arbitrary commands 
> > to a target, which I think would cover this.  
>
>
> dm-ioctl.h:
>   #define DM_TARGET_CTL	 _IOWR(DM_IOCTL, DM_TARGET_CTL_CMD, struct dm_ioctl)
>
>   struct dm_target_ctl {
> 	uint64_t sector;	/* Device sector */
> 	/* Might add size of command string if it simplifies processing */
>
> 	char command[0];
>   };
>
> Is there any legitimate need to supply a list of dm_target_ctl structs
> instead of just one-at-once?

I do not have one.

> Is there any need to allow a string of data to be returned in addition
> to the error code?  [i.e. Are status/table commands sufficient? ]

I also do not have one....

But Christophe V. really does all the userspace stuff, so he would know best.

> Alasdair


--
Mike Christie
mikenc us ibm com