linux-toradex.git/Documentation/device-mapper, branch v4.11-rc3

scripts/spelling.txt: add "explictely" pattern and fix typo instances

2017-02-28T02:43:47+00:00

Fix typos and add the following to the scripts/spelling.txt:

  explictely||explicitly

Link: http://lkml.kernel.org/r/1481573103-11329-25-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dm cache metadata: add "metadata2" feature

2017-02-16T18:12:47+00:00

If "metadata2" is provided as a table argument when creating/loading a
cache target a more compact metadata format, with separate dirty bits,
is used.  "metadata2" improves speed of shutting down a cache target.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer

dm raid: add raid4/5/6 journaling support

2017-01-25T11:49:06+00:00

Add md raid4/5/6 journaling support (upstream commit bac624f3f86a started
the implementation) which closes the write hole (i.e. non-atomic updates
to stripes) using a dedicated journal device.

Background:
raid4/5/6 stripes hold N data payloads per stripe plus one parity raid4/5
or two raid6 P/Q syndrome payloads in an in-memory stripe cache.
Parity or P/Q syndromes used to recover any data payloads in case of a disk
failure are calculated from the N data payloads and need to be updated on the
different component devices of the raid device.  Those are non-atomic,
persistent updates.  Hence a crash can cause failure to update all stripe
payloads persistently and thus cause data loss during stripe recovery.
This problem gets addressed by writing whole stripe cache entries (together with
journal metadata) to a persistent journal entry on a dedicated journal device.
Only if that journal entry is written successfully, the stripe cache entry is
updated on the component devices of the raid device (i.e. writethrough type).
In case of a crash, the entry can be recovered from the journal and be written
again thus ensuring consistent stripe payload suitable to data recovery.

Future dependencies:
once writeback caching being worked on to compensate for the throughput
implictions involved with writethrough overhead is supported with journaling
in upstream, an additional patch based on this one will support it in dm-raid.

Journal resilience related remarks:
because stripes are recovered from the journal in case of a crash, the
journal device better be resilient.  Resilience becomes mandatory with
future writeback support, because loosing the working set in the log
means data loss as oposed to writethrough, were the loss of the
journal device 'only' reintroduces the write hole.

Fix comment on data offsets in parse_dev_params() and initialize
new_data_offset as well.

Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

dm raid: fix transient device failure processing

2017-01-25T11:49:06+00:00

This fix addresses the following 3 failure scenarios:

1) If a (transiently) inaccessible metadata device is being passed into the
constructor (e.g. a device tuple '254:4 254:5'), it is processed as if
'- -' was given.  This erroneously results in a status table line containing
'- -', which mistakenly differs from what has been passed in.  As a result,
userspace libdevmapper puts the device tuple seperate from the RAID device
thus not processing the dependencies properly.

2) False health status char 'A' instead of 'D' is emitted on the status
status info line for the meta/data device tuple in this metadata device
failure case.

3) If the metadata device is accessible when passed into the constructor
but the data device (partially) isn't, that leg may be set faulty by the
raid personality on access to the (partially) unavailable leg.  Restore
tried in a second raid device resume on such failed leg (status char 'D')
fails after the (partial) leg returned.

Fixes for aforementioned failure scenarios:

- don't release passed in devices in the constructor thus allowing the
  status table line to e.g. contain '254:4 254:5' rather than '- -'

- emit device status char 'D' rather than 'A' for the device tuple
  with the failed metadata device on the status info line

- when attempting to restore faulty devices in a second resume, allow the
  device hot remove function to succeed by setting the device to not in-sync

In case userspace intentionally passes '- -' into the constructor to avoid that
device tuple (e.g. to split off a raid1 leg temporarily for later re-addition),
the status table line will correctly show '- -' and the status info line will
provide a '-' device health character for the non-defined device tuple.

Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2016-12-14T19:12:25+00:00

Pull trivial updates from Jiri Kosina.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  NTB: correct ntb_spad_count comment typo
  misc: ibmasm: fix typo in error message
  Remove references to dead make variable LINUX_INCLUDE
  Remove last traces of ikconfig.h
  treewide: Fix printk() message errors
  Documentation/device-mapper: s/getsize/getsz/

Documentation/device-mapper: s/getsize/getsz/

2016-12-14T09:54:27+00:00

According to `man blockdev':

  --getsize
         Print device size (32-bit!) in sectors.
         Deprecated in favor of the --getsz option.
  ...
  --getsz
         Get size in 512-byte sectors.

Hence, occurrences of `--getsize' should be replaced with `--getsz',
which this commit has achieved as follows:

  $ cd "$repo"
  $ git grep -l -e --getsz
  Documentation/device-mapper/delay.txt
  Documentation/device-mapper/dm-crypt.txt
  Documentation/device-mapper/linear.txt
  Documentation/device-mapper/log-writes.txt
  Documentation/device-mapper/striped.txt
  Documentation/device-mapper/switch.txt
  $ cd Documentation/device-mapper
  $ sed -i s/getsize/getsz/g *

Signed-off-by: Michael Witten 
Signed-off-by: Jiri Kosina

Documentation: dm raid: define data_offset status field

2016-12-08T19:13:13+00:00

Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

dm crypt: add ability to use keys from the kernel key retention service

2016-12-08T19:13:09+00:00

The kernel key service is a generic way to store keys for the use of
other subsystems. Currently there is no way to use kernel keys in dm-crypt.
This patch aims to fix that. Instead of key userspace may pass a key
description with preceding ':'. So message that constructs encryption
mapping now looks like this:

   [|:]    [<#opt_params> ]

where  is in format: ::

Currently we only support two elementary key types: 'user' and 'logon'.
Keys may be loaded in dm-crypt either via  or using
classical method and pass the key in hex representation directly.

dm-crypt device initialised with a key passed in hex representation may be
replaced with key passed in key_string format and vice versa.

(Based on original work by Andrey Ryabinin)

Signed-off-by: Ondrej Kozina 
Reviewed-by: David Howells 
Signed-off-by: Mike Snitzer

dm raid: fix typos in Documentation/device-mapper/dm-raid.txt

2016-11-21T14:52:04+00:00

Signed-off-by: Masanari Iida 
Signed-off-by: Mike Snitzer

dm raid: fix activation of existing raid4/10 devices

2016-10-17T20:41:31+00:00

dm-raid 1.9.0 fails to activate existing RAID4/10 devices that have the
old superblock format (which does not have takeover/reshaping support
that was added via commit 33e53f06850f).

Fix validation path for old superblocks by reverting to the old raid4
layout and basing checks on mddev->new_{level,layout,...} members in
super_init_validation().

Cc: stable@vger.kernel.org # 4.8
Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer