linux-kernel - Re: [PATCH 08/18] ide-floppy: use drive->capacity64 for caching current capacity

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Message-Id: <200809271734.55433.bzolnier@gmail.com>
Date:	Sat, 27 Sep 2008 17:34:55 +0200
From:	Bartlomiej Zolnierkiewicz <bzolnier@...il.com>
To:	petkovbb@...il.com
Cc:	linux-ide@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 08/18] ide-floppy: use drive->capacity64 for caching current capacity


Hi,

On Wednesday 10 September 2008, Borislav Petkov wrote:
> Hi,
> 
> On Mon, Sep 08, 2008 at 12:15:19AM +0200, Bartlomiej Zolnierkiewicz wrote:
> > * Use drive->capacity64 for caching current capacity.
> > 
> > * Switch ide_floppy_capacity() to use drive->capacity64.
> > 
> > * Call set_capacity() in idefloppy_open() and ide_floppy_probe()
> >   instead of ide_floppy_get_capacity().
> > 
> > There should be no functional changes caused by this patch.
> > 
> > Cc: Borislav Petkov <petkovbb@...il.com>
> > Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@...il.com>
> > ---
> >  drivers/ide/ide-floppy.c |   23 +++++++++++++----------
> >  1 file changed, 13 insertions(+), 10 deletions(-)
> > 
> > Index: b/drivers/ide/ide-floppy.c
> > ===================================================================
> > --- a/drivers/ide/ide-floppy.c
> > +++ b/drivers/ide/ide-floppy.c
> > @@ -445,7 +445,9 @@ static int ide_floppy_get_flexible_disk_
> >  			drive->name, lba_capacity, capacity);
> >  		floppy->blocks = floppy->block_size ?
> >  			capacity / floppy->block_size : 0;
> > +		drive->capacity64 = floppy->blocks * floppy->bs_factor;
> 
> why do we do the assignment only in the capacity < lba_capacity case?
> drive->capacity64 is the total number of sectors, shouldn't we do
> 
> drive->capacity64 = floppy->blocks;
> 
> in the floppy->bs_factor == 1 case? Otherwise you have the case of calling

Probably we should...

> idefloppy_setup()
> |-> ide_floppy_get_capacity()
>     |-> ide_floppy_get_flexible_disk_page()
> 
> and having drive->capacity64 == 0 in the (capacity >= lba_capacity) case which
> assigns a capacity of 0 to disk->capacity in the set_capacity() call later ...
> 
> or am I missing something?

...my patch just modified the code to also set ->capacity64 in places
which previously were modifying ->blocks and/or ->bs_factor (since
->capacity64 replaced open-coded ->blocks * ->bs_factor calculation),
so I think that the above problem is as an orthogonal issue and it
is the best to address it in separate pre- or post- patch (could you
please take care of it?).

[...]

> > @@ -547,17 +551,12 @@ static int ide_floppy_get_capacity(ide_d
> >  	if (!(drive->atapi_flags & IDE_AFLAG_CLIK_DRIVE))
> >  		(void) ide_floppy_get_flexible_disk_page(drive);
> >  
> > -	set_capacity(disk, floppy->blocks * floppy->bs_factor);
> > -
> >  	return rc;
> >  }
> >  
> >  sector_t ide_floppy_capacity(ide_drive_t *drive)
> >  {
> > -	idefloppy_floppy_t *floppy = drive->driver_data;
> > -	unsigned long capacity = floppy->blocks * floppy->bs_factor;
> > -
> > -	return capacity;
> > +	return drive->capacity64;
> 
> you can simplify this one even further by killing ide_floppy_capacity() and
> doing
> 
> 	set_capacity(disk, floppy->drive->capacity64);

I did it ide_floppy_capacity()-way to match ide_disk_capacity()
and ease the merge (probably ide_gd_capacity() can be removed now).

Thanks,
Bart
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