Re: [Qemu-devel] [PATCH v3 07/10] block: Use bdrv_nb_sectors() where sectors, not bytes are wanted

[Markus Armbruster <armbru@redhat.com>]

Benoît Canet <benoit.canet@irqsave.net> writes:

> The Friday 30 May 2014 à 20:13:48 (+0200), Markus Armbruster wrote :
>> Instead of bdrv_getlength().
>> 
>> Aside: a few of these callers don't handle errors.  I didn't
>> investigate whether they should.
>> 
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
[...]
>> diff --git a/block.c b/block.c
>> index cfeb497..8ebfb79 100644
>> --- a/block.c
>> +++ b/block.c
>> @@ -5258,13 +5258,12 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity,
>>  
>>      granularity >>= BDRV_SECTOR_BITS;
>>      assert(granularity);
>> -    bitmap_size = bdrv_getlength(bs);
>> +    bitmap_size = bdrv_nb_sectors(bs);
>
> The name bitmap_size seems to imply the unit is byte.

I didn't examine how the bitmap is used.  My patch doesn't change the
value put into bitmap_size.

>>      if (bitmap_size < 0) {
>>          error_setg_errno(errp, -bitmap_size, "could not get length of device");
>>          errno = -bitmap_size;
>>          return NULL;
>>      }
>> -    bitmap_size >>= BDRV_SECTOR_BITS;
>>      bitmap = g_malloc0(sizeof(BdrvDirtyBitmap));
>>      bitmap->bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1);
>>      QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list);
[...]