On Mon, Apr 27, 2015 at 08:25:58AM +0800, Qu Wenruo wrote: > > > -------- Original Message -------- > Subject: Re: [PATCH v2 1/2] btrfs: Fix superblock csum type check. > From: David Sterba <dste...@suse.cz> > To: Qu Wenruo <quwen...@cn.fujitsu.com> > Date: 2015年04月24日 23:05 > > > On Fri, Apr 24, 2015 at 09:12:40AM +0800, Qu Wenruo wrote: > >> --- a/fs/btrfs/ctree.h > >> +++ b/fs/btrfs/ctree.h > >> @@ -173,6 +173,7 @@ struct btrfs_ordered_sum; > >> > >> /* csum types */ > >> #define BTRFS_CSUM_TYPE_CRC32 0 > >> +#define BTRFS_CSUM_LAST_TYPE 0 > >> > >> static int btrfs_csum_sizes[] = { 4, 0 }; > > > > I'd prefer to fix it by removing the 0 from btrfs_csum_sizes instead of > > introducing a define. > > > > Removing the zero seems not help for this case, as some one can still > craft a strange csum_type to access outside the array.
The ARRAY_SIZE will be 1, so if a crafted csum will be anything than 0, then the check will catch it, no? > So I introduce the new macro and use the new macro to compare with > csum_type without acess the array. The macro serves the same purpose as the ARRAY_SIZE macro and is always in sync with the btrfs_csum_size. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html