litmus-rt.git/drivers/md/Kconfig, branch v2.6.31-rc7

dm raid1: add userspace log

2009-06-22T09:12:35+00:00

This patch contains a device-mapper mirror log module that forwards
requests to userspace for processing.

The structures used for communication between kernel and userspace are
located in include/linux/dm-log-userspace.h.  Due to the frequency,
diversity, and 2-way communication nature of the exchanges between
kernel and userspace, 'connector' was chosen as the interface for
communication.

The first log implementations written in userspace - "clustered-disk"
and "clustered-core" - support clustered shared storage.   A userspace
daemon (in the LVM2 source code repository) uses openAIS/corosync to
process requests in an ordered fashion with the rest of the nodes in the
cluster so as to prevent log state corruption.  Other implementations
with no association to LVM or openAIS/corosync, are certainly possible.

(Imagine if two machines are writing to the same region of a mirror.
They would both mark the region dirty, but you need a cluster-aware
entity that can handle properly marking the region clean when they are
done.  Otherwise, you might clear the region when the first machine is
done, not the second.)

Signed-off-by: Jonathan Brassow 
Cc: Evgeniy Polyakov 
Signed-off-by: Alasdair G Kergon

dm mpath: add service time load balancer

2009-06-22T09:12:28+00:00

This patch adds a service time oriented dynamic load balancer,
dm-service-time, which selects the path with the shortest estimated
service time for the incoming I/O.
The service time is estimated by dividing the in-flight I/O size
by a performance value of each path.

The performance value can be given as a table argument at the table
loading time.  If no performance value is given, all paths are
considered equal.

Signed-off-by: Kiyoshi Ueda 
Signed-off-by: Jun'ichi Nomura 
Signed-off-by: Alasdair G Kergon

dm mpath: add queue length load balancer

2009-06-22T09:12:27+00:00

This patch adds a dynamic load balancer, dm-queue-length, which
balances the number of in-flight I/Os across the paths.

The code is based on the patch posted by Stefan Bader:
https://www.redhat.com/archives/dm-devel/2005-October/msg00050.html

Signed-off-by: Stefan Bader 
Signed-off-by: Kiyoshi Ueda 
Signed-off-by: Jun'ichi Nomura 
Signed-off-by: Alasdair G Kergon

md: remove CONFIG_MD_RAID_RESHAPE config option.

2009-03-31T04:27:05+00:00

This was only needed when the code was experimental.  Most of it
is well tested now, so the option is no longer useful.

Signed-off-by: NeilBrown

md/raid6: move raid6 data processing to raid6_pq.ko

2009-03-31T04:09:39+00:00

Move the raid6 data processing routines into a standalone module
(raid6_pq) to prepare them to be called from async_tx wrappers and other
non-md drivers/modules.  This precludes a circular dependency of raid456
needing the async modules for data processing while those modules in
turn depend on raid456 for the base level synchronous raid6 routines.

To support this move:
1/ The exportable definitions in raid6.h move to include/linux/raid/pq.h
2/ The raid6_call, recovery calls, and table symbols are exported
3/ Extra #ifdef __KERNEL__ statements to enable the userspace raid6test to
   compile

Signed-off-by: Dan Williams 
Signed-off-by: NeilBrown

raid, fastboot: hide RAID autodetect option if MD is compiled as a module

2008-10-12T15:25:14+00:00

Signed-off-by: Alan Jenkins 
Signed-off-by: Ingo Molnar

raid: make RAID autodetect default a KConfig option

2008-10-12T15:25:02+00:00

RAID autodetect has the side effect of requiring synchronisation
of all device drivers, which can make the boot several seconds longer
(I've measured 7 on one of my laptops).... even for systems that don't
have RAID setup for the root filesystem (the only FS where this matters).

This patch makes the default for autodetect a config option; either way
the user can always override via the kernel command line.

Signed-off-by: Arjan van de Ven 
Acked-by: NeilBrown

[SCSI] scsi_dh: fix kconfig related build errors

2008-07-15T14:16:43+00:00

Do not automatically "select" SCSI_DH for dm-multipath. If SCSI_DH
doesn't exist,just do not allow  hardware handlers to be used.

Handle SCSI_DH being a module also. Make sure it doesn't allow DM_MULTIPATH
to be compiled in when SCSI_DH is a module.

[jejb: added comment for Kconfig syntax]
Signed-off-by: Chandra Seetharaman 
Reported-by: Randy Dunlap 
Reported-by: Andrew Morton 
Signed-off-by: James Bottomley

[SCSI] scsi_dh: Remove hardware handlers from dm

2008-06-05T14:23:41+00:00

This patch removes the 3 hardware handlers that currently exist
under dm as the functionality is moved to SCSI layer in the earlier
patches.

[jejb: removed more makefile hunks and rejection fixes]
Signed-off-by: Chandra Seetharaman 
Acked-by: Alasdair G Kergon 
Signed-off-by: James Bottomley

[SCSI] scsi_dh: Use SCSI device handler in dm-multipath

2008-06-05T14:23:41+00:00

This patch converts dm-mpath to use scsi device handlers instead of
dm's hardware handlers.

This patch does not add any new functionality. Old behaviors remain and
userspace tools work as is except that arguments supplied with hardware
handler are ignored.

One behavioral exception is: Activation of a path is synchronous in this
patch, opposed to the older behavior of being asynchronous (changed in
patch 07: scsi_dh: Add a single threaded workqueue for initializing a path)

Note: There is no need to get a reference for the device handler module
(as it was done in the dm hardware handler case) here as the reference
is held when the device was first found. Instead we check and make sure
that support for the specified device is present at table load time.

Signed-off-by: Chandra Seetharaman 
Signed-off-by: Mike Christie 
Acked-by: Alasdair G Kergon 
Signed-off-by: James Bottomley