def _make_mutate_ops_subvolume(
subvols: TempSubvolumes,
create_ops: Subvol,
path: bytes,
) -> Subvol:
'Exercise the send-stream ops that are unique to snapshots.'
subvol = subvols.snapshot(create_ops, path) # snapshot
run = partial(subvol.run_as_root, cwd=subvol.path())
run(['rm', 'hello/world']) # unlink
run(['rmdir', 'dir_to_remove/']) # rmdir
run([ # remove_xattr
'setfattr',
'--remove=user.test_attr',
'hello/',
])
# You would think this would emit a `rename`, but for files, the
# sendstream instead `link`s to the new location, and unlinks the old.
run(['mv', 'goodbye', 'farewell']) # NOT a rename, {,un}link
run(['mv', 'hello/', 'hello_renamed/']) # yes, a rename!
run( # write
['dd', 'of=hello_renamed/een'],
input=b'push\n',
)
# This is a no-op because `btfs send` does not support `chattr` at
# present. However, it's good to have a canary so that our tests start
# failing the moment it is supported -- that will remind us to update
# the mock VFS. NB: The absolute path to `chattr` is a clowny hack to
# work around a clowny hack, to work around clowny hacks. Don't ask.
run(['/usr/bin/chattr', '+a', 'hello_renamed/een'])
return subvol
def _make_mutate_ops_subvolume(
subvols: TempSubvolumes,
create_ops: Subvol,
path: bytes,
) -> Subvol:
'Exercise the send-stream ops that are unique to snapshots.'
subvol = subvols.snapshot(create_ops, path) # snapshot
run = subvol.run_as_root
# `cwd` is intentionally prohibited with `run_as_root`
def p(sv_path):
return subvol.path(sv_path).decode()
run(['rm', p('hello/world')]) # unlink
run(['rmdir', p('dir_to_remove/')]) # rmdir
run([ # remove_xattr
'setfattr',
'--remove=user.test_attr',
p('hello/'),
])
# You would think this would emit a `rename`, but for files, the
# sendstream instead `link`s to the new location, and unlinks the old.
run(['mv', p('goodbye'), p('farewell')]) # NOT a rename, {,un}link
run(['mv', p('hello/'), p('hello_renamed/')]) # yes, a rename!
run( # write
['dd', 'of=' + p('hello_renamed/een')],
input=b'push\n',
)
# This is a no-op because `btfs send` does not support `chattr` at
# present. However, it's good to have a canary so that our tests start
# failing the moment it is supported -- that will remind us to update
# the mock VFS. NB: The absolute path to `chattr` is a clowny hack to
# work around a clowny hack, to work around clowny hacks. Don't ask.
run(['/usr/bin/chattr', '+a', p('hello_renamed/een')])
# Besides files with trailing holes, one can also get `truncate`
# sendstream commands in incremental sendstreams by having a snapshot
# truncate relative a file relative to the parent.
run(['truncate', '-s', '2', p('hello_big_hole')])
return subvol
