Merge tag 'dm-3.14-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

costs into account and to adjust to varying load patterns automatically.

Message and constructor argument pairs are:

	'sequential_threshold <#nr_sequential_ios>' and

	'random_threshold <#nr_random_ios>'.

	'sequential_threshold <#nr_sequential_ios>'

	'random_threshold <#nr_random_ios>'

	'read_promote_adjustment <value>'

	'write_promote_adjustment <value>'

	'discard_promote_adjustment <value>'

The sequential threshold indicates the number of contiguous I/Os

required before a stream is treated as sequential.  The random threshold

contiguous I/Os to try to spot when the io is in one of these sequential

modes.

Internally the mq policy maintains a promotion threshold variable.  If

the hit count of a block not in the cache goes above this threshold it

gets promoted to the cache.  The read, write and discard promote adjustment

tunables allow you to tweak the promotion threshold by adding a small

value based on the io type.  They default to 4, 8 and 1 respectively.

If you're trying to quickly warm a new cache device you may wish to

reduce these to encourage promotion.  Remember to switch them back to

their defaults after the cache fills though.

cleaner

-------

Status

------

<#used metadata blocks>/<#total metadata blocks> <#read hits> <#read misses>

<#write hits> <#write misses> <#demotions> <#promotions> <#blocks in cache>

<#dirty> <#features> <features>* <#core args> <core args>* <#policy args>

<policy args>*

<metadata block size> <#used metadata blocks>/<#total metadata blocks>

<cache block size> <#used cache blocks>/<#total cache blocks>

<#read hits> <#read misses> <#write hits> <#write misses>

<#demotions> <#promotions> <#dirty> <#features> <features>*

<#core args> <core args>* <policy name> <#policy args> <policy args>*

metadata block size	 : Fixed block size for each metadata block in

			     sectors

#used metadata blocks	 : Number of metadata blocks used

#total metadata blocks	 : Total number of metadata blocks

cache block size	 : Configurable block size for the cache device

			     in sectors

#used cache blocks	 : Number of blocks resident in the cache

#total cache blocks	 : Total number of cache blocks

#read hits		 : Number of times a READ bio has been mapped

			     to the cache

#read misses		 : Number of times a READ bio has been mapped

			     from the cache

#promotions		 : Number of times a block has been moved to

			     the cache

#blocks in cache         : Number of blocks resident in the cache

#dirty			 : Number of blocks in the cache that differ

			     from the origin

#feature args		 : Number of feature args to follow

#core args		 : Number of core arguments (must be even)

core args		 : Key/value pairs for tuning the core

			     e.g. migration_threshold

policy name		 : Name of the policy

#policy args		 : Number of policy arguments to follow (must be even)

policy args		 : Key/value pairs

			     e.g. 'sequential_threshold 1024

			     e.g. sequential_threshold

Messages

--------

      read_only: Don't allow any changes to be made to the pool

		 metadata.

      error_if_no_space: Error IOs, instead of queueing, if no space.

    Data block size must be between 64KB (128 sectors) and 1GB

    (2097152 sectors) inclusive.

	contain the string 'Fail'.  The userspace recovery tools

	should then be used.

    error_if_no_space|queue_if_no_space

	If the pool runs out of data or metadata space, the pool will

	either queue or error the IO destined to the data device.  The

	default is to queue the IO until more space is added.

iii) Messages

    create_thin <dev id>

source "drivers/md/bcache/Kconfig"

config BLK_DEV_DM_BUILTIN

	boolean

config BLK_DEV_DM

	tristate "Device mapper support"

	select BLK_DEV_DM_BUILTIN

	---help---

	  Device-mapper is a low level volume manager.  It works by allowing

	  people to specify mappings for ranges of logical sectors.  Various

config DM_SNAPSHOT

       tristate "Snapshot target"

       depends on BLK_DEV_DM

       select DM_BUFIO

       ---help---

         Allow volume managers to take writable snapshots of a device.

         Provides thin provisioning and snapshots that share a data store.

config DM_DEBUG_BLOCK_STACK_TRACING

	boolean "Keep stack trace of thin provisioning block lock holders"

	depends on STACKTRACE_SUPPORT && DM_THIN_PROVISIONING

	boolean "Keep stack trace of persistent data block lock holders"

	depends on STACKTRACE_SUPPORT && DM_PERSISTENT_DATA

	select STACKTRACE

	---help---

	  Enable this for messages that may help debug problems with the

	  block manager locking used by thin provisioning.

	  block manager locking used by thin provisioning and caching.

	  If unsure, say N.

obj-$(CONFIG_BCACHE)		+= bcache/

obj-$(CONFIG_BLK_DEV_MD)	+= md-mod.o

obj-$(CONFIG_BLK_DEV_DM)	+= dm-mod.o

obj-$(CONFIG_BLK_DEV_DM_BUILTIN) += dm-builtin.o

obj-$(CONFIG_DM_BUFIO)		+= dm-bufio.o

obj-$(CONFIG_DM_BIO_PRISON)	+= dm-bio-prison.o

obj-$(CONFIG_DM_CRYPT)		+= dm-crypt.o