Btrfs and endian convert

[Qu Wenruo]

On 2020/4/9 下午2:27, Qu Wenruo wrote:
> Hi Marek,
> 
> I respect your independent implementation of btrfs inside U-boot, but it
> looks like the code is too creative, other than follow the regular btrfs
> code.
> 
> One of the biggest problem is, there is no convert of on-disk endian and
> in-memory endian.
> 
> The most obvious proof is the lack of btrfs_disk_key, on-disk
> btrfs_disk_key is returned and used against native endian btrfs_key.
> 
> Is U-boot only supposed to be run on little endian system?

My bad, you do the convert the convert at different timing.

For header and item/node ptr, it's converted as tree block read time,
while for other structures, you do the convert when reading them.

This is pretty different from what we do in kernel/progs.

> 
> And, would you mind me to do the full cross port of btrfs-progs code to
> U-boot?
> I found a lot of practice pretty far away from the common code base of
> btrfs-progs and kernel, like using on-disk key pointer a lot (which
> should be avoid due to endian convert).
> 
> Mind me to re-build the btrfs implementation from scratch?

While this still stands, as latest btrfs_tree.h would include both
btrfs_key and btrfs_disk_key, if we really want to sync the header, we
still need to go the regular BTRFS_SETGET_* macros way.

Thanks,
Qu

> 
> Thanks,
> Qu
> 

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