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Linus Torvalds b25c6644bf - Largest change for this cycle is the DM zoned target's metadata
version 2 feature that adds support for pairing regular block
   devices with a zoned device to ease performance impact associated
   with finite random zones of zoned device.  Changes came in 3
   batches: first prepared for and then added the ability to pair a
   single regular block device, second was a batch of fixes to improve
   zoned's reclaim heuristic, third removed the limitation of only
   adding a single additional regular block device to allow many
   devices.  Testing has shown linear scaling as more devices are
   added.
 
 - Add new emulated block size (ebs) target that emulates a smaller
   logical_block_size than a block device supports.  Primary use-case
   is to emulate "512e" devices that have 512 byte logical_block_size
   and 4KB physical_block_size.  This is useful to some legacy
   applications otherwise wouldn't be ablee to be used on 4K devices
   because they depend on issuing IO in 512 byte granularity.
 
 - Add discard interfaces to DM bufio.  First consumer of the interface
   is the dm-ebs target that makes heavy use of dm-bufio.
 
 - Fix DM crypt's block queue_limits stacking to not truncate
   logic_block_size.
 
 - Add Documentation for DM integrity's status line.
 
 - Switch DMDEBUG from a compile time config option to instead use
   dynamic debug via pr_debug.
 
 - Fix DM multipath target's hueristic for how it manages
   "queue_if_no_path" state internally.  DM multipath now avoids
   disabling "queue_if_no_path" unless it is actually needed (e.g. in
   response to configure timeout or explicit "fail_if_no_path"
   message).  This fixes reports of spurious -EIO being reported back
   to userspace application during fault tolerance testing with an NVMe
   backend.  Added various dynamic DMDEBUG messages to assist with
   debugging queue_if_no_path in the future.
 
 - Add a new DM multipath "Historical Service Time" Path Selector.
 
 - Fix DM multipath's dm_blk_ioctl() to switch paths on IO error.
 
 - Improve DM writecache target performance by using explicit
   cache flushing for target's single-threaded usecase and a small
   cleanup to remove unnecessary test in persistent_memory_claim.
 
 - Other small cleanups in DM core, dm-persistent-data, and DM integrity.
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Merge tag 'for-5.8/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - The largest change for this cycle is the DM zoned target's metadata
   version 2 feature that adds support for pairing regular block devices
   with a zoned device to ease the performance impact associated with
   finite random zones of zoned device.

   The changes came in three batches: the first prepared for and then
   added the ability to pair a single regular block device, the second
   was a batch of fixes to improve zoned's reclaim heuristic, and the
   third removed the limitation of only adding a single additional
   regular block device to allow many devices.

   Testing has shown linear scaling as more devices are added.

 - Add new emulated block size (ebs) target that emulates a smaller
   logical_block_size than a block device supports

   The primary use-case is to emulate "512e" devices that have 512 byte
   logical_block_size and 4KB physical_block_size. This is useful to
   some legacy applications that otherwise wouldn't be able to be used
   on 4K devices because they depend on issuing IO in 512 byte
   granularity.

 - Add discard interfaces to DM bufio. First consumer of the interface
   is the dm-ebs target that makes heavy use of dm-bufio.

 - Fix DM crypt's block queue_limits stacking to not truncate
   logic_block_size.

 - Add Documentation for DM integrity's status line.

 - Switch DMDEBUG from a compile time config option to instead use
   dynamic debug via pr_debug.

 - Fix DM multipath target's hueristic for how it manages
   "queue_if_no_path" state internally.

   DM multipath now avoids disabling "queue_if_no_path" unless it is
   actually needed (e.g. in response to configure timeout or explicit
   "fail_if_no_path" message).

   This fixes reports of spurious -EIO being reported back to userspace
   application during fault tolerance testing with an NVMe backend.
   Added various dynamic DMDEBUG messages to assist with debugging
   queue_if_no_path in the future.

 - Add a new DM multipath "Historical Service Time" Path Selector.

 - Fix DM multipath's dm_blk_ioctl() to switch paths on IO error.

 - Improve DM writecache target performance by using explicit cache
   flushing for target's single-threaded usecase and a small cleanup to
   remove unnecessary test in persistent_memory_claim.

 - Other small cleanups in DM core, dm-persistent-data, and DM
   integrity.

* tag 'for-5.8/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (62 commits)
  dm crypt: avoid truncating the logical block size
  dm mpath: add DM device name to Failing/Reinstating path log messages
  dm mpath: enhance queue_if_no_path debugging
  dm mpath: restrict queue_if_no_path state machine
  dm mpath: simplify __must_push_back
  dm zoned: check superblock location
  dm zoned: prefer full zones for reclaim
  dm zoned: select reclaim zone based on device index
  dm zoned: allocate zone by device index
  dm zoned: support arbitrary number of devices
  dm zoned: move random and sequential zones into struct dmz_dev
  dm zoned: per-device reclaim
  dm zoned: add metadata pointer to struct dmz_dev
  dm zoned: add device pointer to struct dm_zone
  dm zoned: allocate temporary superblock for tertiary devices
  dm zoned: convert to xarray
  dm zoned: add a 'reserved' zone flag
  dm zoned: improve logging messages for reclaim
  dm zoned: avoid unnecessary device recalulation for secondary superblock
  dm zoned: add debugging message for reading superblocks
  ...
2020-06-05 15:45:03 -07:00
arch Split the old READ_IMPLIES_EXEC workaround from executable PT_GNU_STACK 2020-06-05 13:45:21 -07:00
block for-5.8/drivers-2020-06-01 2020-06-02 15:37:03 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: engine - do not requeue in case of fatal error 2020-05-28 17:27:52 +10:00
Documentation - Largest change for this cycle is the DM zoned target's metadata 2020-06-05 15:45:03 -07:00
drivers - Largest change for this cycle is the DM zoned target's metadata 2020-06-05 15:45:03 -07:00
fs RDMA 5.8 merge window pull request 2020-06-05 14:05:57 -07:00
include - Largest change for this cycle is the DM zoned target's metadata 2020-06-05 15:45:03 -07:00
init Kconfig: add config option for asm goto w/ outputs 2020-06-04 19:28:07 -07:00
ipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-06-03 16:27:18 -07:00
kernel powerpc updates for 5.8 2020-06-05 12:39:30 -07:00
lib ARM/SoC: drivers for v5.7 2020-06-04 19:56:20 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm powerpc updates for 5.8 2020-06-05 12:39:30 -07:00
net RDMA 5.8 merge window pull request 2020-06-05 14:05:57 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-06-03 16:27:18 -07:00
scripts Devicetree updates for v5.8: 2020-06-04 20:11:25 -07:00
security Merge branch 'akpm' (patches from Andrew) 2020-06-04 19:18:29 -07:00
sound powerpc updates for 5.8 2020-06-05 12:39:30 -07:00
tools This is the bulk of GPIO changes for the v5.8 kernel cycle. 2020-06-05 14:00:30 -07:00
usr kbuild: fix comment about missing include guard detection 2020-04-11 12:09:48 +09:00
virt A fair amount of stuff this time around, dominated by yet another massive 2020-06-01 15:45:27 -07:00
.clang-format block: add bio_for_each_bvec_all() 2020-05-25 11:25:24 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
.mailmap A fair amount of stuff this time around, dominated by yet another massive 2020-06-01 15:45:27 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS mailmap: change email for Ricardo Ribalda 2020-05-25 18:59:59 -06:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS SCSI misc on 20200605 2020-06-05 15:11:50 -07:00
Makefile arm64 updates for 5.8 2020-06-01 15:18:27 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.