[blivet][master/rhel7-branch] Re-write the DASD storage code. (#1001070)

Vratislav Podzimek vpodzime at redhat.com
Tue Feb 25 11:54:13 UTC 2014


On Tue, 2014-02-25 at 04:30 -0500, Samantha N. Bueno wrote:
> This gets rid of the DASD class and instead introduces a small
> number of functions to interface with and manage DASDs. This is
> completely divorced from the anaconda code and much more
> lightweight.
> 
> (The corresponding Fedora bug for this is 859997.)
> 
> Resolves:rhbz#1001070
> 
> ---
>  blivet/__init__.py        |  13 ++-
>  blivet/dasd.py            | 222 ----------------------------------------------
>  blivet/devicelibs/dasd.py | 134 ++++++++++++++++++++++++++++
>  blivet/devicetree.py      |   6 +-
>  4 files changed, 143 insertions(+), 232 deletions(-)
>  delete mode 100644 blivet/dasd.py
>  create mode 100644 blivet/devicelibs/dasd.py

> diff --git a/blivet/devicelibs/dasd.py b/blivet/devicelibs/dasd.py
> new file mode 100644
> index 0000000..7b71552
> --- /dev/null
> +++ b/blivet/devicelibs/dasd.py
> @@ -0,0 +1,134 @@
> +#
> +# dasd.py - DASD functions
> +#
> +# Copyright (C) 2013 Red Hat, Inc.  All rights reserved.
> +#
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 2 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>.
> +#
> +# Red Hat Author(s): Samantha N. Bueno
> +#
> +
> +import os
> +from blivet.errors import DasdFormatError
> +from blivet.devices import deviceNameToDiskByPath
> +from blivet import util
> +from blivet import arch
> +from blivet.udev import udev_trigger
> +
> +import logging
> +log = logging.getLogger("blivet")
> +
> +import gettext
> +_ = lambda x: gettext.ldgettext("blivet", x)
> +P_ = lambda x, y, z: gettext.ldngettext("blivet", x, y, z)
> +
> +def get_dasd_ports():
> +    """ Return comma delimited string of valid DASD ports. """
> +    ports = []
> +
> +    with open("/proc/dasd/devices", "r") as f:
> +        lines = (line.strip() for line in f.readlines())
> +        f.close()
The with block closes the file for you. And I believe you need to close
the file after reading lines not after creating the generator. So you
should drop the f.close() line and indent the for loop more to become a
part of the with block.

> +
> +    for line in lines:
> +        if "unknown" in line:
> +            continue
> +
> +        if "(FBA )" in line or "(ECKD)" in line:
> +            ports.append(line.split('(')[0])
> +
> +    return ','.join(ports)
> +
> +def format_dasd(dasd):
> +    """ Run dasdfmt on a DASD. Aside from one type of device noted below, this
> +        function _does not_ check if a DASD needs to be formatted, but rather,
> +        assumes the list passed needs formatting.
> +
> +        We don't need to show or update any progress bars, since disk actions
> +        will be taking place all in the progress hub, which is just one big
> +        progress bar.
> +    """
> +    try:
> +        rc = util.run_program(["/sbin/dasdfmt", "-y", "-d", "cdl", "-b", "4096", "/dev/" + dasd])
> +    except Exception as err:
> +        raise DasdFormatError(err)
> +
> +    if rc:
> +        raise DasdFormatError("dasdfmt failed: %s" % rc)
> +
> +def clear_dasd_list(dasds):
> +    """ Zero out the list of DASDs. """
> +    dasds = []
> +    return dasds
Same question as with the previous version of the patch -- do you want
to clear the passed list or just return a new empty one?

> +
> +def make_dasd_list(dasds, devicetree):
> +    """ Create a list of DASDs recognized by the system. """
> +    if not arch.isS390():
> +        return
> +
> +    # Trigger udev data about the dasd devices on the system
> +    udev_trigger(action="change", name="dasd*")
> +    log.info("Generating DASD list...")
> +    for dev in devicetree.getDevicesByType("dasd"):
> +        if dev not in dasds:
> +            dasds.append(dev)
> +
> +    return dasds
> +
> +def make_unformatted_dasd_list(dasds):
> +    """ Return a list of DASDS which are not formatted. """
> +    unformatted = []
> +
> +    for dasd in dasds:
> +        if dasd_needs_format(dasd):
> +            unformatted.append(dasd)
> +
> +    return unformatted
> +
> +def dasd_needs_format(dasd):
> +    """ Check if a DASD needs to have dasdfmt run against it or not.
> +        Return True if we do need dasdfmt, False if not.
> +    """
> +    statusfile = "/sys/block/%s/device/status" % (dasd,)
> +    if not os.path.isfile(statusfile):
> +        return False
> +
> +    with open(statusfile, "r") as f:
> +        status = f.read().strip()
> +        f.close()
No need to close the file explicitly in the with block. The same applies
in one more place few lines below.

-- 
Vratislav Podzimek

Anaconda Rider | Red Hat, Inc. | Brno - Czech Republic



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