[PATCH 0/6] overlayfs + casefolding

[Kent Overstreet <kent.overstreet@linux.dev>]

This series allows overlayfs and casefolding to safely be used on the
same filesystem by providing exclusion to ensure that overlayfs never
has to deal with casefolded directories.

Currently, overlayfs can't be used _at all_ if a filesystem even
supports casefolding, which is really nasty for users.

Components:

- filesystem has to track, for each directory, "does any _descendent_
  have casefolding enabled"

- new inode flag to pass this to VFS layer

- new dcache methods for providing refs for overlayfs, and filesystem
  methods for safely clearing this flag

- new superblock flag for indicating to overlayfs & dcache "filesystem
  supports casefolding, it's safe to use provided new dcache methods are
  used"

Kent Overstreet (6):
  bcachefs: BCH_INODE_has_case_insensitive
  darray: lift from bcachefs
  fs: SB_CASEFOLD
  fs: dcache locking for exlusion between overlayfs, casefolding
  bcachefs: Hook up d_casefold_enable()
  overlayfs: Support casefolded filesystems

 MAINTAINERS                             |   7 +
 fs/bcachefs/Makefile                    |   1 -
 fs/bcachefs/bcachefs_format.h           |   3 +-
 fs/bcachefs/btree_node_scan_types.h     |   2 +-
 fs/bcachefs/btree_types.h               |   2 +-
 fs/bcachefs/btree_update.c              |   1 +
 fs/bcachefs/btree_write_buffer_types.h  |   2 +-
 fs/bcachefs/disk_accounting_types.h     |   2 +-
 fs/bcachefs/fs.c                        |  45 +++++-
 fs/bcachefs/fsck.c                      |  12 +-
 fs/bcachefs/inode.c                     |   8 +-
 fs/bcachefs/inode.h                     |   2 +-
 fs/bcachefs/inode_format.h              |   7 +-
 fs/bcachefs/journal_io.h                |   2 +-
 fs/bcachefs/journal_sb.c                |   2 +-
 fs/bcachefs/namei.c                     | 166 +++++++++++++++++++++-
 fs/bcachefs/namei.h                     |   5 +
 fs/bcachefs/rcu_pending.c               |   3 +-
 fs/bcachefs/sb-downgrade.c              |   9 +-
 fs/bcachefs/sb-errors_format.h          |   4 +-
 fs/bcachefs/sb-errors_types.h           |   2 +-
 fs/bcachefs/sb-members.h                |   3 +-
 fs/bcachefs/snapshot_types.h            |   3 +-
 fs/bcachefs/subvolume.h                 |   1 -
 fs/bcachefs/thread_with_file_types.h    |   2 +-
 fs/bcachefs/util.h                      |  28 +---
 fs/dcache.c                             | 177 ++++++++++++++++++++++++
 fs/libfs.c                              |   1 +
 fs/overlayfs/params.c                   |  20 ++-
 fs/overlayfs/util.c                     |  19 ++-
 {fs/bcachefs => include/linux}/darray.h |  70 +++++-----
 include/linux/darray_types.h            |  33 +++++
 include/linux/dcache.h                  |  10 ++
 include/linux/fs.h                      |   4 +
 lib/Makefile                            |   2 +-
 {fs/bcachefs => lib}/darray.c           |   9 +-
 36 files changed, 571 insertions(+), 98 deletions(-)
 rename {fs/bcachefs => include/linux}/darray.h (64%)
 create mode 100644 include/linux/darray_types.h
 rename {fs/bcachefs => lib}/darray.c (75%)

-- 
2.49.0