Message-ID: <6fcddba84070c021eb92aa9a5ff15fb2a47e9acb.camel@perches.com>
Subject: Re: [PATCH] xen-blkfront: Use the bitmap API when applicable
From:   Joe Perches <joe@perches.com>
To:     Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Juergen Gross <jgross@suse.com>, boris.ostrovsky@oracle.com,
        sstabellini@kernel.org, roger.pau@citrix.com, axboe@kernel.dk
Cc:     xen-devel@lists.xenproject.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Date:   Thu, 02 Dec 2021 10:16:23 -0800
In-Reply-To: <d8f87c17-75d1-2e6b-65e1-23adc75bb515@wanadoo.fr>
References: <1c73cf8eaff02ea19439ec676c063e592d273cfe.1638392965.git.christophe.jaillet@wanadoo.fr>
         <c529a221-f444-ad26-11ff-f693401c9429@suse.com>
         <d8f87c17-75d1-2e6b-65e1-23adc75bb515@wanadoo.fr>
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On Thu, 2021-12-02 at 19:12 +0100, Christophe JAILLET wrote:
> Le 02/12/2021 ? 07:12, Juergen Gross a ?crit?:
> > On 01.12.21 22:10, Christophe JAILLET wrote:
> > > Use 'bitmap_zalloc()' to simplify code, improve the semantic and avoid 
> > > some open-coded arithmetic in allocator arguments.
> > > 
> > > Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
> > > consistency.
> > > 
> > > Use 'bitmap_copy()' to avoid an explicit 'memcpy()'
[]
> > > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
[]
> > > @@ -442,16 +442,14 @@ static int xlbd_reserve_minors(unsigned int 
> > > minor, unsigned int nr)
> > > ????? if (end > nr_minors) {
> > > ????????? unsigned long *bitmap, *old;
> > > -??????? bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap),
> > > -???????????????? GFP_KERNEL);
> > > +??????? bitmap = bitmap_zalloc(end, GFP_KERNEL);
> > > ????????? if (bitmap == NULL)
> > > ????????????? return -ENOMEM;
> > > ????????? spin_lock(&minor_lock);
> > > ????????? if (end > nr_minors) {
> > > ????????????? old = minors;
> > > -??????????? memcpy(bitmap, minors,
> > > -?????????????????? BITS_TO_LONGS(nr_minors) * sizeof(*bitmap));
> > > +??????????? bitmap_copy(bitmap, minors, nr_minors);
> > > ????????????? minors = bitmap;
> > > ????????????? nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG;

		nr_minors = end;
?