[PATCH v4 0/2] remove BUG_ON()s in btrfs_close_one_device()

[Johannes Thumshirn <jthumshirn@suse.de>]

This series attempts to remove the BUG_ON()s in btrfs_close_one_device().
Therefore some reorganization of btrfs_close_one_device() was needed, to
avoid the memory allocation.

This series has passed fstests without any deviation from the baseline.

Changes to v3:
- Clear BTRFS_DEV_STATE_WRITEABLE after calling btrfs_close_bdev() so
  btrfs_close_bdev() can call sync_blockdev() and invalidate_bdev() (Nikolay)

Changes to v2:
- Completly different approach to the origianl patchset, instead of handling
  eventual allocation failures.
- Dropped already merged patches for ' btrfs_fs_devices::rotating' and
  'btrfs_fs_devices::seeding'
- Kept the 1st patch of the old series, as it's a nice cleanup

Changes to v1:
- Fixed the decremt of btrfs_fs_devices::seeding.
- In addition to this, I've added two patches changing btrfs_fs_devices::seeding
  and btrfs_fs_devices::rotating to bool, as they are in fact used as booleans.

Johannes Thumshirn (2):
  btrfs: decrement number of open devices after closing the device not
    before
  btrfs: reset device back to allocation state when removing

 fs/btrfs/volumes.c | 41 ++++++++++++++++++-----------------------
 1 file changed, 18 insertions(+), 23 deletions(-)

-- 
2.16.4