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Date:   Thu, 25 Jul 2019 16:48:35 +0530
From:   Bharath Vedartham <linux.bhar@gmail.com>
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     ira.weiny@intel.com, jglisse@redhat.com,
        Matt.Sickler@daktronics.com, jhubbard@nvidia.com,
        devel@driverdev.osuosl.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4] staging: kpc2000: Convert put_page to put_user_page*()
Message-ID: <20190725111834.GA12517@bharath12345-Inspiron-5559>
References: <20190720173214.GA4250@bharath12345-Inspiron-5559>
 <20190725074634.GB15090@kroah.com>
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On Thu, Jul 25, 2019 at 09:46:34AM +0200, Greg KH wrote:
> On Sat, Jul 20, 2019 at 11:02:14PM +0530, Bharath Vedartham wrote:
> > For pages that were retained via get_user_pages*(), release those pages
> > via the new put_user_page*() routines, instead of via put_page().
> > 
> > This is part a tree-wide conversion, as described in commit fc1d8e7cca2d ("mm: introduce put_user_page*(), placeholder versions").
> 
> Please line-wrap this line.
> 
> > 
> > Cc: Ira Weiny <ira.weiny@intel.com>
> > Cc: John Hubbard <jhubbard@nvidia.com>
> > Cc: J?r?me Glisse <jglisse@redhat.com>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: Matt Sickler <Matt.Sickler@daktronics.com>
> > Cc: devel@driverdev.osuosl.org
> > Cc: linux-kernel@vger.kernel.org
> > Cc: linux-mm@kvack.org
> > Reviewed-by: John Hubbard <jhubbard@nvidia.com>
> > Signed-off-by: Bharath Vedartham <linux.bhar@gmail.com>
> > ---
> > Changes since v1
> >        - Improved changelog by John's suggestion.
> >        - Moved logic to dirty pages below sg_dma_unmap
> >        and removed PageReserved check.
> > Changes since v2
> >        - Added back PageResevered check as suggested by John Hubbard.
> > Changes since v3
> >        - Changed the commit log as suggested by John.
> >        - Added John's Reviewed-By tag
> > 
> > ---
> >  drivers/staging/kpc2000/kpc_dma/fileops.c | 17 ++++++-----------
> >  1 file changed, 6 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/staging/kpc2000/kpc_dma/fileops.c b/drivers/staging/kpc2000/kpc_dma/fileops.c
> > index 6166587..75ad263 100644
> > --- a/drivers/staging/kpc2000/kpc_dma/fileops.c
> > +++ b/drivers/staging/kpc2000/kpc_dma/fileops.c
> > @@ -198,9 +198,7 @@ int  kpc_dma_transfer(struct dev_private_data *priv, struct kiocb *kcb, unsigned
> >  	sg_free_table(&acd->sgt);
> >   err_dma_map_sg:
> >   err_alloc_sg_table:
> > -	for (i = 0 ; i < acd->page_count ; i++){
> > -		put_page(acd->user_pages[i]);
> > -	}
> > +	put_user_pages(acd->user_pages, acd->page_count);
> >   err_get_user_pages:
> >  	kfree(acd->user_pages);
> >   err_alloc_userpages:
> > @@ -221,16 +219,13 @@ void  transfer_complete_cb(struct aio_cb_data *acd, size_t xfr_count, u32 flags)
> >  	
> >  	dev_dbg(&acd->ldev->pldev->dev, "transfer_complete_cb(acd = [%p])\n", acd);
> >  	
> > -	for (i = 0 ; i < acd->page_count ; i++){
> > -		if (!PageReserved(acd->user_pages[i])){
> > -			set_page_dirty(acd->user_pages[i]);
> > -		}
> > -	}
> > -	
> >  	dma_unmap_sg(&acd->ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, acd->ldev->dir);
> >  	
> > -	for (i = 0 ; i < acd->page_count ; i++){
> > -		put_page(acd->user_pages[i]);
> > +	for (i = 0; i < acd->page_count; i++) {
> > +		if (!PageReserved(acd->user_pages[i]))
> > +			put_user_pages_dirty(&acd->user_pages[i], 1);
> > +		else
> > +			put_user_page(acd->user_pages[i]);
> >  	}
> >  	
> >  	sg_free_table(&acd->sgt);
> > -- 
> > 2.7.4
> 
> This patch can not be applied at all :(
> 
> Can you redo it against the latest staging-next branch and resend?
> 
> thanks,
Yup. Will do that!
> greg k-h