On Sun, Jan 06, 2008 at 01:44:34AM +0100, [EMAIL PROTECTED] wrote:
> +static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, __u32
> index)
> +{
> + struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[index];
> + int nr_groups = (map->s_partition_len + (sizeof(struct spaceBitmapDesc)
> << 3) +
> + (sb->s_blocksize * 8) - 1) / (sb->s_blocksize * 8);
> + int size = sizeof(struct udf_bitmap) + (sizeof(struct buffer_head *) *
> nr_groups);
> + struct udf_bitmap *bitmap;
> +
> + if (size <= PAGE_SIZE)
> + bitmap = kmalloc(size, GFP_KERNEL);
> + else
> + bitmap = vmalloc(size);
> + if (bitmap != NULL) {
> + memset(bitmap, 0x00, size);
> + bitmap->s_block_bitmap = (struct buffer_head **)(bitmap + 1);
> + bitmap->s_nr_groups = nr_groups;
> + } else
> + udf_error(sb, __FUNCTION__, "Unable to allocate space for
> bitmap and %d buffer_head pointers", nr_groups);
> + return bitmap;
> +}
There's some overly long lines here and some odd style, this should look
more like:
static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb,
u32 index)
{
struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[index];
struct udf_bitmap *bitmap;
int nr_groups;
int size;
nr_groups = (map->s_partition_len +
(sizeof(struct spaceBitmapDesc) << 3) +
(sb->s_blocksize * 8) - 1) /
(sb->s_blocksize * 8);
size = sizeof(struct udf_bitmap) +
(sizeof(struct buffer_head *) * nr_groups);
if (size <= PAGE_SIZE)
bitmap = kmalloc(size, GFP_KERNEL);
else
bitmap = vmalloc(size);
if (!bitmap) {
udf_error(sb, __FUNCTION__,
"Unable to allocate space for bitmap "
"and %d buffer_head pointers", nr_groups);
return NULL;
}
memset(bitmap, 0, size);
bitmap->s_block_bitmap = (struct buffer_head **)(bitmap + 1);
bitmap->s_nr_groups = nr_groups;
return bitmap;
}
But even that is not quite optimal. The nr_groups calculation should
probably move to a helper (I suspect it's used elsewhere too anyway),
and instead of using vmalloc for large allocations I'd rather split
the allocation of the bitmap from s->block_bitmap and use individual
smaller allocations. But that latter part is probably better left
for a separate patch.
But in generally this is a good cleanup and thanks a lot for working
on this filesystem driver.
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