[PATCH 0/6] Support resize and device delete cancel ops

[David Sterba <dsterba@suse.com>]

We don't have a nice interface to cancel the resize or device deletion
from a command. Since recently, both commands can be interrupted by a
signal, which also means Ctrl-C from terminal, but given the long
history of absence of the commands I think this is not yet well known.

Examples:

  $ btrfs fi resize -10G /mnt
  ...
  $ btrfs fi resize cancel /mnt

  $ btrfs device delete /dev/sdx /mnt
  ...
  $ btrfs device delete cancel /mnt

The cancel request returns once the resize/delete command finishes
processing of the currently relocated chunk. The btrfs-progs needs to be
updated as well to skip checks of the sysfs exclusive_operation file
added in 5.10 (raw ioctl would work).

David Sterba (6):
  btrfs: protect exclusive_operation by super_lock
  btrfs: add cancelable chunk relocation support
  btrfs: introduce try-lock semantics for exclusive op start
  btrfs: add wrapper for conditional start of exclusive operation
  btrfs: add cancelation to resize
  btrfs: add device delete cancel

 fs/btrfs/ctree.h      |  16 +++-
 fs/btrfs/disk-io.c    |   1 +
 fs/btrfs/ioctl.c      | 174 ++++++++++++++++++++++++++++++++----------
 fs/btrfs/relocation.c |  60 ++++++++++++++-
 4 files changed, 207 insertions(+), 44 deletions(-)

-- 
2.29.2