[PATCH 0/3] better error messages for ioctls

This fixes a common user complaint - uninformative error messages from
various bcachefs-tools commands.

Add v2 versions of various ioctls that include a 'struct
bch_ioctl_err_mesg', a pointer to a userspace buffer for an error
message - and plumb a printbuf through various code for returning
errors.

Kent Overstreet (3):
  bcachefs: Add v2 ioctls that return error strings
  bcachefs: v2 versions of subvolume ioctls
  bcachefs: Plumb error messages through data drop paths

 fs/bcachefs/bcachefs_ioctl.h |  87 ++++++++++++++-----
 fs/bcachefs/chardev.c        | 159 +++++++++++++++++++++++++++++++++--
 fs/bcachefs/chardev.h        |   3 +
 fs/bcachefs/ec.c             |  23 +++--
 fs/bcachefs/ec.h             |   5 +-
 fs/bcachefs/fs-ioctl.c       |  91 ++++++++++++++++++--
 fs/bcachefs/migrate.c        |  55 ++++++------
 fs/bcachefs/migrate.h        |   4 +-
 fs/bcachefs/super.c          |   6 +-
 9 files changed, 359 insertions(+), 74 deletions(-)

-- 
2.50.1