by Bartlomiej Zolnierkiewicz

[permalink] [raw]

Subject: Re: [PATCH 0/32] ide-tape redux v1

On Monday 28 January 2008, Borislav Petkov wrote:
> Hi Bart,
>
> [...]
>
> > > the BKL in idetape_write_release() with finer-grained locking etc, probably also
> > > some pipeline improvements, removal of OnStream support, etc. but that'll come
> > > later.
> >
> > On-Stream support has been long gone but it seems that deprecation
> > warning etc. managed to survive.
> >
> > w.r.t. to the pipeline-mode: it should be pipelined into /dev/null
> >
> > rationale:
> > - it is _very_ complex
> > - causes errors to be deferred till the next user-space access
> > - direct I/O using blk_rq_map_user() will offer superior performance
> >
> > the only question is whether to remove it...
>
> Well, on the one hand, since the driver is only being maintained we should not
> remove code that works. Also, i don't know how many users ide-tape really has
> but, would it be worth the trouble at all? Because if nobody's using it, we
> could just as well pipe the whole thing into /dev/null.. On the other hand, the

This may be the other alternative... [ there is always libata PATA... ]

If you want to give ide-tape removal a try, go ahead (I suggest starting
with adding warning printk() and keeping patch in -mm for some time)...

> pipelining part _is_ kinda big and, right, it is not that straightfoward to
> look at it and know what it actually does - it truly is a student project :)

I have pipelining code figured out to some degree but reworking it is a rather
low-prio on my TODO list...

[...]

> Anyway, resending #23 to you in a private mail.

Thanks.

Bart

2008-02-01 08:22:58

by Borislav Petkov

[permalink] [raw]

Subject: Re: [PATCH 0/32] ide-tape redux v1

On Wed, Jan 30, 2008 at 01:29:55AM +0100, Bartlomiej Zolnierkiewicz wrote:
> On Monday 28 January 2008, Borislav Petkov wrote:
> > Hi Bart,
> >
> > [...]
> >
> > > > the BKL in idetape_write_release() with finer-grained locking etc, probably also
> > > > some pipeline improvements, removal of OnStream support, etc. but that'll come
> > > > later.
> > >
> > > On-Stream support has been long gone but it seems that deprecation
> > > warning etc. managed to survive.
> > >
> > > w.r.t. to the pipeline-mode: it should be pipelined into /dev/null
> > >
> > > rationale:
> > > - it is _very_ complex
> > > - causes errors to be deferred till the next user-space access
> > > - direct I/O using blk_rq_map_user() will offer superior performance
> > >
> > > the only question is whether to remove it...
> >
> > Well, on the one hand, since the driver is only being maintained we should not
> > remove code that works. Also, i don't know how many users ide-tape really has
> > but, would it be worth the trouble at all? Because if nobody's using it, we
> > could just as well pipe the whole thing into /dev/null.. On the other hand, the
>
> This may be the other alternative... [ there is always libata PATA... ]
>
> If you want to give ide-tape removal a try, go ahead (I suggest starting
> with adding warning printk() and keeping patch in -mm for some time)...

Well, we don't have any numbers on whether someone is using the driver at all,
so i probably the best thing we should do is give it a grace period of 1/2 year
before we get rid of it. In the meantime, let's see how many souls cry out :)

---
commit 5b4566d1ed9b050d53d776285da84f8c3cc13d2c
Author: Borislav Petkov <[email protected]>
Date: Fri Feb 1 09:12:02 2008 +0100

ide-tape: schedule driver for removal after 6 months in case it doesn't have
any users left.

Signed-off-by: Borislav Petkov <[email protected]>

diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 20c4c8b..21d71a9 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -333,3 +333,13 @@ Why: This driver has been marked obsolete for many years.
Who: Stephen Hemminger <[email protected]>

---------------------------
+
+What: ide-tape driver
+When: July 2008
+Files: drivers/ide/ide-tape.c
+Why: This driver might not have any users anymore and maintaining it for no
+ reason is an effort no one wants to make.
+Who: Bartlomiej Zolnierkiewicz <[email protected]>, Borislav Petkov
+ <[email protected]>
+
+---------------------------
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index f51712c..fd81f4c 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -3829,6 +3829,11 @@ static int ide_tape_probe(ide_drive_t *drive)
g->fops = &idetape_block_ops;
ide_register_region(g);

+ printk(KERN_WARNING "It is possible that this driver does not have any"
+ " users anymore and, as a result, it will be REMOVED soon."
+ " Please notify Bart <[email protected]> or Boris"
+ " <[email protected]> in case you still need it.\n");
+
return 0;

out_free_tape:

--
Regards/Gru?,
Boris.