Re: [PATCH v3] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

From: Jan Kara
Date: Fri Aug 28 2020 - 06:29:51 EST


On Thu 27-08-20 17:29:25, Gustavo A. R. Silva wrote:
>
>
> On 8/27/20 17:16, Denis Efremov wrote:
> > Use kvzalloc() in udf_sb_alloc_bitmap() instead of open-coding it.
> > Size computation wrapped in struct_size() macro to prevent potential
> > integer overflows.
> >
> > Signed-off-by: Denis Efremov <efremov@xxxxxxxxx>
>
> Looks good. :)
>
> Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thank you both. I've added the patch to my tree.

Honza

>
> Thanks
> --
> Gustavo
>
> > ---
> > Changes in v2:
> > - size computation wrapped in struct_size()
> > Changes in v3:
> > - int size dropped
> >
> > fs/udf/super.c | 14 +++-----------
> > 1 file changed, 3 insertions(+), 11 deletions(-)
> >
> > diff --git a/fs/udf/super.c b/fs/udf/super.c
> > index 1c42f544096d..d9eabbe368ff 100644
> > --- a/fs/udf/super.c
> > +++ b/fs/udf/super.c
> > @@ -1006,18 +1006,10 @@ int udf_compute_nr_groups(struct super_block *sb, u32 partition)
> > static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
> > {
> > struct udf_bitmap *bitmap;
> > - int nr_groups;
> > - int size;
> > -
> > - nr_groups = udf_compute_nr_groups(sb, index);
> > - size = sizeof(struct udf_bitmap) +
> > - (sizeof(struct buffer_head *) * nr_groups);
> > -
> > - if (size <= PAGE_SIZE)
> > - bitmap = kzalloc(size, GFP_KERNEL);
> > - else
> > - bitmap = vzalloc(size); /* TODO: get rid of vzalloc */
> > + int nr_groups = udf_compute_nr_groups(sb, index);
> >
> > + bitmap = kvzalloc(struct_size(bitmap, s_block_bitmap, nr_groups),
> > + GFP_KERNEL);
> > if (!bitmap)
> > return NULL;
> >
> >
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR