btrfs: functional test cases for tempfsid

v4: Do not optimize calling _require_..() due to duplicates at the
testcase level.
    Fix the failure of btrfs/315 due to changes in the mount command
error output.
    btrfs/312 remove unused ret and drop args check in now local func
create_cloned_devices.

v3: Mainly, move the prerequisite checks
  _require_btrfs_command inspect-internal dump-super
  _require_btrfs_mkfs_uuid_option
to the common/btrfs function mkfs_clone() and move
  _require_btrfs_command inspect-internal dump-super
to check_fsid() from each individual testcase.
A few more changes as in each individual testcase.

v2: Each individual patch has undergone numerous fixes based on the
feedback received. Please refer to the individual patches.

This patch set validates the tempfsid feature in Btrfs, testing its
functionality and limitations. Also, has one minor bug fix.

Anand Jain (10):
  assign SCRATCH_DEV_POOL to an array
  btrfs: introduce tempfsid test group
  btrfs: create a helper function, check_fsid(), to verify the tempfsid
  btrfs: verify that subvolume mounts are unaffected by tempfsid
  btrfs: check if cloned device mounts with tempfsid
  btrfs: test case prerequisite _require_btrfs_mkfs_uuid_option
  btrfs: introduce helper for creating cloned devices with mkfs
  btrfs: verify tempfsid clones using mkfs
  btrfs: validate send-receive operation with tempfsid.
  btrfs: test tempfsid with device add, seed, and balance

 common/btrfs        | 74 ++++++++++++++++++++++++++++++++++++
 common/rc           | 18 +++++++--
 doc/group-names.txt |  1 +
 tests/btrfs/311     | 87 +++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/311.out | 24 ++++++++++++
 tests/btrfs/312     | 78 ++++++++++++++++++++++++++++++++++++++
 tests/btrfs/312.out | 19 ++++++++++
 tests/btrfs/313     | 52 ++++++++++++++++++++++++++
 tests/btrfs/313.out | 16 ++++++++
 tests/btrfs/314     | 78 ++++++++++++++++++++++++++++++++++++++
 tests/btrfs/314.out | 23 ++++++++++++
 tests/btrfs/315     | 91 +++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/315.out | 10 +++++
 13 files changed, 567 insertions(+), 4 deletions(-)
 create mode 100755 tests/btrfs/311
 create mode 100644 tests/btrfs/311.out
 create mode 100755 tests/btrfs/312
 create mode 100644 tests/btrfs/312.out
 create mode 100755 tests/btrfs/313
 create mode 100644 tests/btrfs/313.out
 create mode 100755 tests/btrfs/314
 create mode 100644 tests/btrfs/314.out
 create mode 100755 tests/btrfs/315
 create mode 100644 tests/btrfs/315.out

-- 
2.39.3