Source code for crash.commands.btrfs

# -*- coding: utf-8 -*-
# vim:set shiftwidth=4 softtabstop=4 expandtab textwidth=79:
"""
SUMMARY
-------

Display Btrfs internal data structures

::

  btrfs <command> <superblock>

COMMANDS
--------

  ``btrfs list [-m]`` -- list all btrfs file systems (-m to show metadata uuid)
"""

import argparse
from crash.commands import Command, ArgumentParser
from crash.commands import CommandLineError
from crash.subsystem.filesystem import for_each_super_block, super_fstype
from crash.subsystem.filesystem.btrfs import btrfs_fsid, btrfs_metadata_uuid

class _Parser(ArgumentParser):
    def format_usage(self) -> str:
        return "btrfs <subcommand> [args...]\n"

class BtrfsCommand(Command):
    """display Btrfs internal data structures"""

    def __init__(self, name: str) -> None:
        parser = _Parser(prog=name)
        subparsers = parser.add_subparsers(help="sub-command help")
        list_parser = subparsers.add_parser('list', help='list help')
        list_parser.set_defaults(subcommand=self.list_btrfs)
        list_parser.add_argument('-m', action='store_true', default=False)

        Command.__init__(self, name, parser)

    def list_btrfs(self, args: argparse.Namespace) -> None:
        print_header = True
        count = 0
        for sb in for_each_super_block():
            if super_fstype(sb) == "btrfs":
                if args.m:
                    u = btrfs_metadata_uuid(sb)
                    which_fsid = "METADATA UUID"
                else:
                    u = btrfs_fsid(sb)
                    which_fsid = "FSID"
                if print_header:
                    print("SUPER BLOCK\t\tDEVICE\t\t{}".format(which_fsid))
                    print_header = False
                print("{}\t{}\t\t{}".format(sb.address, sb['s_id'].string(), u))
                count += 1
        if count == 0:
            print("No btrfs file systems were mounted.")

    def execute(self, args: argparse.Namespace) -> None:
        if hasattr(args, 'subcommand'):
            args.subcommand(args)
        else:
            raise CommandLineError("no command specified")

BtrfsCommand("btrfs")