linux-stable.git/Documentation/admin-guide/device-mapper, branch v5.19.2

dm writecache: count number of blocks discarded, not number of discard bios

2022-08-17T13:14:18+00:00

[ Upstream commit 2ee73ef60db4d79b9f9b8cd501e8188b5179449f ]

Change dm-writecache, so that it counts the number of blocks discarded
instead of the number of discard bios. Make it consistent with the
read and write statistics counters that were changed to count the
number of blocks instead of bios.

Fixes: e3a35d03407c ("dm writecache: add event counters")
Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin

dm writecache: count number of blocks written, not number of write bios

2022-08-17T13:14:18+00:00

[ Upstream commit b2676e1482af89714af6988ce5d31a84692e2530 ]

Change dm-writecache, so that it counts the number of blocks written
instead of the number of write bios. Bios can be split and requeued
using the dm_accept_partial_bio function, so counting bios caused
inaccurate results.

Fixes: e3a35d03407c ("dm writecache: add event counters")
Reported-by: Yu Kuai 
Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin

dm writecache: count number of blocks read, not number of read bios

2022-08-17T13:14:18+00:00

[ Upstream commit 2c6e755b49d273243431f5f1184654e71221fc78 ]

Change dm-writecache, so that it counts the number of blocks read
instead of the number of read bios. Bios can be split and requeued
using the dm_accept_partial_bio function, so counting bios caused
inaccurate results.

Fixes: e3a35d03407c ("dm writecache: add event counters")
Reported-by: Yu Kuai 
Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin

dm ima: update dm documentation for ima measurement support

2021-08-20T20:07:37+00:00

The ima documentation for measuring DM targets (dm-ima.rst) is
missing the attribute information for the targets - 'cache', 'integrity',
'multipath', and 'snapshot'.  It is also missing the grammar for
various DM events and targets, which can help the attestation servers
to determine what data to expect for a given DM device.  Further,
the documentation needs to be updated to incorporate code changes
made to DM ima events and targets as part of this patch series.  For
instance, prefixing the event names with "dm_", adding the DM version to
events, prefixing the table hashes in the ima log with the
hash algorithm etc.  There are warnings reported by 'make htmldocs' on
dm-ima.rst, which need to be fixed.  And lastly, the expected behavior
needs to be documented when the configuration CONFIG_IMA_DISABLE_HTABLE
is disabled.

Update the documentation to add examples for 'cache', 'integrity',
'multipath', and 'snapshot' targets.  Add the grammar for
various DM events and targets in Backus Naur form,
so that the attestation servers can interpret and act on the ima
measurements for DM target.  Fix htmldocs warnings in dm-ima.rst.  Update
the documentation to be consistent with the code changes that are part of
this patch series.

Reported-by: Stephen Rothwell 
Signed-off-by: Tushar Sugandhi 
Signed-off-by: Mike Snitzer

dm: add documentation for IMA measurement support

2021-08-10T17:34:23+00:00

To interpret various DM target measurement data in IMA logs,
a separate documentation page is needed under
Documentation/admin-guide/device-mapper.

Add documentation to help system administrators and attestation
client/server component owners to interpret the measurement
data generated by various DM targets, on various device/table state
changes.

Signed-off-by: Tushar Sugandhi 
Signed-off-by: Mike Snitzer

dm writecache: add event counters

2021-08-10T17:27:49+00:00

Add 10 counters for various events (hit, miss, etc) and export them in
the status line (accessed from userspace with "dmsetup status"). Also
add a message "clear_stats" that resets these counters.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer

dm writecache: make writeback pause configurable

2021-06-28T20:30:13+00:00

Commit 95b88f4d71cb953e02206be3c757083601391a0f ("dm writecache: pause
writeback if cache full and origin being written directly") introduced a
code that pauses cache flushing if we are issuing writes directly to the
origin.

Improve that initial commit by making the timeout code configurable
(via the option "pause_writeback"). Also change the default from 1s to
3s because it performed better.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer

dm writecache: add optional "metadata_only" parameter

2021-06-25T19:25:21+00:00

Add a "metadata_only" parameter that when present: only metadata is
promoted to the cache. This option improves performance for heavier
REQ_META workloads (e.g. device-mapper-test-suite's "git clone and
checkout" benchmark improves from 341s to 312s).

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer

dm writecache: add "cleaner" and "max_age" to Documentation

2021-06-25T19:25:19+00:00

Backfill missing Documentation.

Fixes: 93de44eb3fc8 ("dm writecache: implement the "cleaner" policy")
Fixes: 3923d4854e18 ("dm writecache: implement gradual cleanup")
Signed-off-by: Mike Snitzer

Merge tag 'for-5.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2021-02-22T18:22:54+00:00

Pull device mapper updates from Mike Snitzer:

 - Fix DM integrity's HMAC support to provide enhanced security of
   internal_hash and journal_mac capabilities.

 - Various DM writecache fixes to address performance, fix table output
   to match what was provided at table creation, fix writing beyond end
   of device when shrinking underlying data device, and a couple other
   small cleanups.

 - Add DM crypt support for using trusted keys.

 - Fix deadlock when swapping to DM crypt device by throttling number of
   in-flight REQ_SWAP bios. Implemented in DM core so that other
   bio-based targets can opt-in by setting ti->limit_swap_bios.

 - Fix various inverted logic bugs in the .iterate_devices callout
   functions that are used to assess if specific feature or capability
   is supported across all devices being combined/stacked by DM.

 - Fix DM era target bugs that exposed users to lost writes or memory
   leaks.

 - Add DM core support for passing through inline crypto support of
   underlying devices. Includes block/keyslot-manager changes that
   enable extending this support to DM.

 - Various small fixes and cleanups (spelling fixes, front padding
   calculation cleanup, cleanup conditional zoned support in targets,
   etc).

* tag 'for-5.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (31 commits)
  dm: fix deadlock when swapping to encrypted device
  dm: simplify target code conditional on CONFIG_BLK_DEV_ZONED
  dm: set DM_TARGET_PASSES_CRYPTO feature for some targets
  dm: support key eviction from keyslot managers of underlying devices
  dm: add support for passing through inline crypto support
  block/keyslot-manager: Introduce functions for device mapper support
  block/keyslot-manager: Introduce passthrough keyslot manager
  dm era: only resize metadata in preresume
  dm era: Use correct value size in equality function of writeset tree
  dm era: Fix bitset memory leaks
  dm era: Verify the data block size hasn't changed
  dm era: Reinitialize bitset cache before digesting a new writeset
  dm era: Update in-core bitset after committing the metadata
  dm era: Recover committed writeset after crash
  dm writecache: use bdev_nr_sectors() instead of open-coded equivalent
  dm writecache: fix writing beyond end of underlying device when shrinking
  dm table: remove needless request_queue NULL pointer checks
  dm table: fix zoned iterate_devices based device capability checks
  dm table: fix DAX iterate_devices based device capability checks
  dm table: fix iterate_devices based device capability checks
  ...