[PATCH U-BOOT v2 00/30] fs: btrfs: Re-implement btrfs support using the more widely used extent buffer base code

[Qu Wenruo]

Gentle ping?

Any updates?
Hopes this won't block the incoming new features too long.

Thanks,
Qu

On 2020/5/25 下午2:32, Qu Wenruo wrote:
> The branch can be fetched from github:
> https://github.com/adam900710/u-boot/tree/btrfs_rebuild
> 
> The current btrfs code in U-boot is using a creative way to read on-disk
> data.
> It's pretty simple, involving the least amount of code, but pretty
> different from btrfs-progs nor kernel, making it pretty hard to sync
> code between different projects.
> 
> This big patchset will rework the btrfs support, to use code mostly from
> btrfs-progs, thus all existing btrfs developers will feel at home.
> 
> During the rework, the following new features are added:
> - More hash algorithm support
>   SHA256 and XXHASH support are added.
>   BLAKE2 needs more backport, will happen in a separate patchset.
> 
> - The ability to read degraded RAID1
>   Although we still only support one device btrfs, the new code base
>   can choose from different copies already.
>   As long as new device scan interface is provided, multi-device support
>   is pretty simple.
> 
> - More correct handling of compressed extents with offset
>   For compressed extent with offset, we should read the whole compressed
>   extent, decompress them, then copy the referred part.
> 
> There are some more features incoming, with the new code base it would
> be much easier to implement:
> - Data checksum support
>   The check would happen in read_extent_data(), btrfs-progs has the
>   needed facility to locate data csum.
> 
> - BLAKE2 support
>   Need BLAKE2 library cross ported.
>   For btrfs it's just several lines of modification.
> 
> - Multi-device support along wit degraded RAID support
>   We only need an interface to scan one device without opening it.
>   The infrastructure is already provided in this patchset.
> 
> These new features would be submitted after the patchset get merged,
> since the patchset is already large, I don't want to make it more scary.
> 
> Although this patchset look horribly large, most of them are code copy
> from btrfs-progs.
> E.g extent-cache.[ch], rbtree-utils.[ch], btrfs_btree.h.
> And ctree.h has over 1000 lines copied just for various accessors.
> 
> While for disk-io.[ch] and volumes-io.[ch], they have some small
> modifications to adapt the interface of U-boot.
> E.g. btrfs_device::fd is replace with blkdev_desc and disk_partition_t.
> 
> The new code for U-boot are related to the following functions:
> - btrfs_readlink()
> - btrfs_lookup_path()
> - btrfs_read_extent_inline()
> - btrfs_read_extent_reg()
> - lookup_data_extent()
> - btrfs_file_read()
> - btrfs_list_subvols()
> 
> Thus only the following 5 patches need extra review attention:
> - Patch 0017
> - Patch 0019
> - Patch 0023
> - Patch 0024
> - Patch 0025~0028
> 
> Changelog:
> v2:
> - Implement btrfs_list_subvols()
>   In v1 it's completely removed thus would cause problem if btrfsolume
>   command is compiled in.
> 
> - Rebased to latest master
>   Only minor conflicts due to header changes.
> 
> - Allow next_legnth() to return value > BTRFS_NAME_LEN
> 
> Qu Wenruo (30):
>   fs: btrfs: Sync btrfs_btree.h from kernel
>   fs: btrfs: Add More checksum algorithm support to btrfs
>   fs: btrfs: Cross-port btrfs_read_dev_super() from btrfs-progs
>   fs: btrfs: Cross-port rbtree-utils from btrfs-progs
>   fs: btrfs: Cross-port extent-cache.[ch] from btrfs-progs
>   fs: btrfs: Cross-port extent-io.[ch] from btrfs-progs
>   fs: btrfs: Cross port structure accessor into ctree.h
>   fs: btrfs: Cross port volumes.[ch] from btrfs-progs
>   fs: btrfs: Crossport read_tree_block() from btrfs-progs
>   fs: btrfs: Rename struct btrfs_path to struct __btrfs_path
>   fs: btrfs: Rename btrfs_root to __btrfs_root
>   fs: btrfs: Cross port struct btrfs_root to ctree.h
>   fs: btrfs: Crossport btrfs_search_slot() from btrfs-progs
>   fs: btrfs: Crossport btrfs_read_sys_array() and
>     btrfs_read_chunk_tree()
>   fs: btrfs: Crossport open_ctree_fs_info()
>   fs: btrfs: Rename path resolve related functions to avoid name
>     conflicts
>   fs: btrfs: Use btrfs_readlink() to implement __btrfs_readlink()
>   fs: btrfs: inode: Allow next_length() to return value > BTRFS_NAME_LEN
>   fs: btrfs: Implement btrfs_lookup_path()
>   fs: btrfs: Use btrfs_iter_dir() to replace btrfs_readdir()
>   fs: btrfs: Use btrfs_lookup_path() to implement btrfs_exists() and
>     btrfs_size()
>   fs: btrfs: Rename btrfs_file_read() and its callees to avoid name
>     conflicts
>   fs: btrfs: Introduce btrfs_read_extent_inline() and
>     btrfs_read_extent_reg()
>   fs: btrfs: Introduce lookup_data_extent() for later use
>   fs: btrfs: Implement btrfs_file_read()
>   fs: btrfs: Introduce function to reolve path in one subvolume
>   fs: btrfs: Introduce function to resolve the path of one subvolume
>   fs: btrfs: Imeplement btrfs_list_subvols() using new infrastructure
>   fs: btrfs: Cleanup the old implementation
>   MAINTAINERS: Add btrfs mail list
> 
>  MAINTAINERS                         |    1 +
>  fs/btrfs/Makefile                   |    5 +-
>  fs/btrfs/btrfs.c                    |  319 +++---
>  fs/btrfs/btrfs.h                    |   67 +-
>  fs/btrfs/btrfs_tree.h               |  766 --------------
>  fs/btrfs/chunk-map.c                |  178 ----
>  fs/btrfs/common/rbtree-utils.c      |   83 ++
>  fs/btrfs/common/rbtree-utils.h      |   53 +
>  fs/btrfs/compat.h                   |   88 ++
>  fs/btrfs/compression.c              |    2 +-
>  fs/btrfs/crypto/hash.c              |   55 +
>  fs/btrfs/crypto/hash.h              |   17 +
>  fs/btrfs/ctree.c                    |  866 ++++++++++++----
>  fs/btrfs/ctree.h                    | 1453 ++++++++++++++++++++++-----
>  fs/btrfs/dir-item.c                 |  192 ++--
>  fs/btrfs/disk-io.c                  | 1063 ++++++++++++++++++++
>  fs/btrfs/disk-io.h                  |   50 +
>  fs/btrfs/extent-cache.c             |  318 ++++++
>  fs/btrfs/extent-cache.h             |  104 ++
>  fs/btrfs/extent-io.c                |  848 ++++++++++++++--
>  fs/btrfs/extent-io.h                |  164 +++
>  fs/btrfs/hash.c                     |   38 -
>  fs/btrfs/inode.c                    |  892 +++++++++++-----
>  fs/btrfs/kernel-shared/btrfs_tree.h | 1333 ++++++++++++++++++++++++
>  fs/btrfs/root-tree.c                |   47 +
>  fs/btrfs/root.c                     |   92 --
>  fs/btrfs/subvolume.c                |  310 ++++--
>  fs/btrfs/super.c                    |  257 -----
>  fs/btrfs/volumes.c                  | 1173 +++++++++++++++++++++
>  fs/btrfs/volumes.h                  |  204 ++++
>  30 files changed, 8537 insertions(+), 2501 deletions(-)
>  delete mode 100644 fs/btrfs/btrfs_tree.h
>  delete mode 100644 fs/btrfs/chunk-map.c
>  create mode 100644 fs/btrfs/common/rbtree-utils.c
>  create mode 100644 fs/btrfs/common/rbtree-utils.h
>  create mode 100644 fs/btrfs/compat.h
>  create mode 100644 fs/btrfs/crypto/hash.c
>  create mode 100644 fs/btrfs/crypto/hash.h
>  create mode 100644 fs/btrfs/disk-io.c
>  create mode 100644 fs/btrfs/disk-io.h
>  create mode 100644 fs/btrfs/extent-cache.c
>  create mode 100644 fs/btrfs/extent-cache.h
>  create mode 100644 fs/btrfs/extent-io.h
>  delete mode 100644 fs/btrfs/hash.c
>  create mode 100644 fs/btrfs/kernel-shared/btrfs_tree.h
>  create mode 100644 fs/btrfs/root-tree.c
>  delete mode 100644 fs/btrfs/root.c
>  delete mode 100644 fs/btrfs/super.c
>  create mode 100644 fs/btrfs/volumes.c
>  create mode 100644 fs/btrfs/volumes.h
>