[Stgt-devel] [PATCH] Make changes so that VTL stuff works properly ...

[FUJITA Tomonori]

On Mon, 28 Jul 2008 20:09:34 -0700
"Richard Sharpe" <realrichardsharpe at gmail.com> wrote:

> On Mon, Jul 28, 2008 at 7:49 PM, Mark Harvey <markh794 at gmail.com> wrote:
> > Richard Sharpe wrote:
> >>>
> >>> From a16d368a29298170df2c21fd19d8490c248f06b1 Mon Sep 17 00:00:00 2001
> >>
> >> From: Richard Sharpe <realrichardsharpe at gmail.com>
> >> Date: Mon, 28 Jul 2008 14:34:12 -0700
> >> Subject: [PATCH] Make changes so that VTL stuff works properly ...
> >> Signed-off-by: Richard Sharpe <realrichardsharpe at gmail.com>
> >>
> >> There are three changes here.
> >>
> >> In target.h I expose device_lookup for use by the smc.c code.
> >>
> >> In target.h I modify tgt_device_path_update so that we can call it to
> >> both open and close a file that has been allocated to a
> >> data_transfer_station.
> >>
> >> In smc.c I modified set_slot_full and set_slot_empty to call the
> >> modified tgt_device_path_update to achieve my goals. We call
> >> device_lookup to figure out the device we are interested in.
> >>
> >> I have tested this by loading and unloading tapes and DVDs, doing tar
> >> to the drive and using cdrecord on the device, and verifying with lsof
> >> that the tgtd has the files open when they are in the transfer station
> >> and does not have them open when the station has been unloaded.
> >>
> >> It all seems to work. I have attached the patch as well because gmail
> >> seems to kill patches ... I hope the attached patch is OK.
> >
> > Sorry, I don't quite understand the reason for this patch.
> >
> > The smc already calls a non-static dtd_load_unload() which performs a
> > similar function to tgt_device_path_update() but with different args.
> >
> > int dtd_load_unload(int tid, uint64_t lun, int load, char *file)
> > vs
> > int tgt_device_path_update(struct target *target, struct scsi_lu *lu, char
> > *path)
> >
> > i.e. dtd_load_unload calls __device_lookup() and then opens/closes the
> > backing store.
> >
> > All this patch seems to do is call the 'open' or 'close' backing store
> > twice.
> >
> >
> > Perhaps 'fixing' dtd_load_unload() so it then calls tgt_device_path_update()
> > if this function is not correct.
> >
> > FWIW: dtd_load_unload == Data Transfer Device load/unload
> >
> > At the time this function was added, the tgt_device_path_update() did not
> > exist.
> 
> All I know is that the current code segfaults when you ask for a tape
> to be loaded into the transfer station.

Can you tell me what commands you performs? I want to reproduce the
ssc segfault to see what's wrong.