When new node becomes enable by hot-add, new sysfs file must be created for
new node. So, if new node is enabled by add_memory(), register_one_node() is
called to create it. In addition, I386's arch_register_node() and a part of
register_nodes() of powerpc are consolidated to register_one_node() as a
generic_code().
This is tested by Tiger4(IPF) with node hot-plug emulation.
Signed-off-by: Keiichiro Tokunaga <tokuanga.keiich@jp.fujitsu.com>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is to find node id from acpi's handle of memory_device in DSDT. _PXM for
the new node can be found by acpi_get_pxm() by using new memory's handle. So,
node id can be found by pxm_to_nid_map[].
This patch becomes simpler than v2 of node hot-add patch.
Because old add_memory() function doesn't have node id parameter.
So, kernel must find its handle by physical address via DSDT again.
But, v3 just give node id to add_memory() now.
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Change the name of old add_memory() to arch_add_memory. And use node id to
get pgdat for the node at NODE_DATA().
Note: Powerpc's old add_memory() is defined as __devinit. However,
add_memory() is usually called only after bootup.
I suppose it may be redundant. But, I'm not well known about powerpc.
So, I keep it. (But, __meminit is better at least.)
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When acpi_memory_device_init() is called at boottime to register struct
memory acpi_memory_device, acpi_bus_add() are called via
acpi_driver_attach().
But it also calls ops->start() function. It is called even if the memory
blocks are initialized at early boottime. In this case add_memory() return
-EEXIST, and the memory blocks becomes INVALID state even if it is normal.
This is patch to avoid calling add_memory() for already available memory.
[akpm@osdl.org: coding cleanups]
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is a patch to call add_memroy() when notify reaches for new node's add
event.
When new node is added, notify of ACPI reaches container device which means
the node.
Container device driver calls acpi_bus_scan() to find and add belonging
devices (which means cpu, memory and so on). Its function calls add and
start function of belonging devices's driver.
Howevever, current memory hotplug driver just register add function to
create sysfs file for its memory. But, acpi_memory_enable_device() is not
called because it is considered just the case that notify reaches memory
device directly. So, if notify reaches container device nothing can call
add_memory().
This is a patch to create start function which calls add_memory().
add_memory() can be called by this when notify reaches container device.
[akpm@osdl.org: coding cleanups]
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Current acpi memory hotplug just looks into the first entry of resources in
_CRS. But, _CRS can contain plural resources. So, if _CRS contains plural
resoureces, acpi memory hot add cannot add all memory.
With this patch, acpi memory hotplug can deal with Memory Device, whose
_CRS contains plural resources.
Tested on ia64 memory hotplug test envrionment (not emulation, uses alpha
version firmware which supports dynamic reconfiguration of NUMA.)
Note: Microsoft's Windows Server 2003 requires big (>4G)resoureces to be
divided into small (<4G) resources. looks crazy, but not invalid.
(See http://www.microsoft.com/whdc/system/pnppwr/hotadd/hotaddmem.mspx)
For this reason, a firmware vendor who supports Windows writes plural
resources in a _CRS even if they are contiguous.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It should be done before calling class_device_unregister() because
it will destroy the device and free memory if there are no other
references to the device.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Mark Bellon found a bug in my tlclk driver. Thanks!
I botch the register mask for store_received_ref_clk3a.
See http://download.intel.com/design/network/manuals/30412001.pdf
tables 124 and 136 for details.
Signed-off-by: Mark Gross <mark.gross@intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial:
typo fixes
Clean up 'inline is not at beginning' warnings for usb storage
Storage class should be first
i386: Trivial typo fixes
ixj: make ixj_set_tone_off() static
spelling fixes
fix paniced->panicked typos
Spelling fixes for Documentation/atomic_ops.txt
move acknowledgment for Mark Adler to CREDITS
remove the bouncing email address of David Campbell
The changes in the tty handling contain a bug while accessing
the last byte in the skb. Since special sequence for control of
DTMF and FAX via ttyI* devices handled via this path, these services
do not work anymore.
Signed-off-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This was spotted by coverity #id 1300. Since the array has only four
elements, we should just use those four.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Acked-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This reverts commit c7b2eff059.
Hugh Dickins explains:
"It seems too little tested: "losetup -d /dev/loop0" fails with
EINVAL because nothing sets lo_thread; but even when you patch
loop_thread() to set lo->lo_thread = current, it can't survive
more than a few dozen iterations of the loop below (with a tmpfs
mounted on /tst):
j=0
cp /dev/zero /tst
while :
do
let j=j+1
echo "Doing pass $j"
losetup /dev/loop0 /tst/zero
mkfs -t ext2 -b 1024 /dev/loop0 >/dev/null 2>&1
mount -t ext2 /dev/loop0 /mnt
umount /mnt
losetup -d /dev/loop0
done
it collapses with failed ioctl then BUG_ON(!bio).
I think the original lo_done completion was more subtle and safe
than the kthread conversion has allowed for."
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (40 commits)
kbuild: trivial fixes in Makefile
kbuild: adding symbols in Kconfig and defconfig to TAGS
kbuild: replace abort() with exit(1)
kbuild: support for %.symtypes files
kbuild: fix silentoldconfig recursion
kbuild: add option for stripping modules while installing them
kbuild: kill some false positives from modpost
kbuild: export-symbol usage report generator
kbuild: fix make -rR breakage
kbuild: append -dirty for updated but uncommited changes
kbuild: append git revision for all untagged commits
kbuild: fix module.symvers parsing in modpost
kbuild: ignore make's built-in rules & variables
kbuild: bugfix with initramfs
kbuild: modpost build fix
kbuild: check license compatibility when building modules
kbuild: export-type enhancement to modpost.c
kbuild: add dependency on kernel.release to the package targets
kbuild: `make kernelrelease' speedup
kconfig: KCONFIG_OVERWRITECONFIG
...
* master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb:
V4L/DVB (4227): Update this driver for recent header file movement.
V4L/DVB (4223): Add V4L2_CID_MPEG_STREAM_VBI_FMT control
V4L/DVB (4222): Always switch tuner mode when calling VIDIOC_S_FREQUENCY.
V4L/DVB (4221): Add HM12 YUV format define.
V4L/DVB (4219): Av7110: analog sound output of DVB-C rev 2.3
V4L/DVB (4217): Fix a misplaced closing bracket/else, which caused swzigzag not to be called
V4L/DVB (4215): Make VIDEO_CX88_BLACKBIRD a separate build option
V4L/DVB (4214): Make VIDEO_CX2341X a selectable build option
V4L/DVB (4213): Cx88: cleanups
V4L/DVB (4211): Fix an Oops for all fe that have get_frontend_algo == NULL
CC drivers/pci/msi-apic.o
In file included from include/asm/msi.h:11,
from drivers/pci/msi.h:71,
from drivers/pci/msi-apic.c:8:
include/asm/smp.h:103: error: syntax error before '->' token
akpm: nasty. It appears to be
static inline unsigned int cpu_mask_to_apicid(cpumask_t cpumask)
conflicting with include/asm-x86_64/mach_apic.h's
#define cpu_mask_to_apicid (genapic->cpu_mask_to_apicid)
And I don't know which patch in rc4-mm1 triggered this.
Fixing this in the .c file seems wrong.
Including asm/smp.h instead of linux/smp.h seems wrong too. Need that
.config.
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
During some profiling I noticed that default_idle causes a lot of
memory traffic. I think that is caused by the atomic operations
to clear/set the polling flag in thread_info. There is actually
no reason to make this atomic - only the idle thread does it
to itself, other CPUs only read it. So I moved it into ti->status.
Converted i386/x86-64/ia64 for now because that was the easiest
way to fix ACPI which also manipulates these flags in its idle
function.
Cc: Nick Piggin <npiggin@novell.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Rename the GART_IOMMU option to IOMMU to make clear it's not
just for AMD
- Rewrite the help text to better emphatise this fact
- Make it an embedded option because too many people get it wrong.
To my astonishment I discovered the aacraid driver tests this
symbol directly. This looks quite broken to me - it's an internal
implementation detail of the PCI DMA API. Can the maintainer
please clarify what this test was intended to do?
Cc: linux-scsi@vger.kernel.org
Cc: alan@redhat.com
Cc: markh@osdl.org
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Factor out the duplicated access/cache code into a single file
* Shared between i386/x86-64.
- Share flush code between AGP and IOMMU
* Fix a bug: AGP didn't wait for end of flush before
- Drop 8 northbridges limit and allocate dynamically
- Add lock to serialize AGP and IOMMU GART flushes
- Add PCI ID for next AMD northbridge
- Random related cleanups
The old K8 NUMA discovery code is unchanged. New systems
should all use SRAT for this.
Cc: "Navin Boppuri" <navin.boppuri@newisys.com>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
[SPARC]: Add iomap interfaces.
[OPENPROM]: Rewrite driver to use in-kernel device tree.
[OPENPROMFS]: Rewrite using in-kernel device tree and seq_file.
[SPARC]: Add unique device_node IDs and a ".node" property.
[SPARC]: Add of_set_property() interface.
[SPARC64]: Export auxio_register to modules.
[SPARC64]: Add missing interfaces to dma-mapping.h
[SPARC64]: Export _PAGE_IE to modules.
[SPARC64]: Allow floppy driver to build modular.
[SPARC]: Export x_bus_type to modules.
[RIOWATCHDOG]: Fix the build.
[CPWATCHDOG]: Fix the build.
[PARPORT] sunbpp: Fix typo.
[MTD] sun_uflash: Port to new EBUS device layer.
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6: (42 commits)
[IOAT]: Do not dereference THIS_MODULE directly to set unsafe.
[NETROM]: Fix possible null pointer dereference.
[NET] netpoll: break recursive loop in netpoll rx path
[NET] netpoll: don't spin forever sending to stopped queues
[IRDA]: add some IBM think pads
[ATM]: atm/mpc.c warning fix
[NET]: skb_find_text ignores to argument
[NET]: make net/core/dev.c:netdev_nit static
[NET]: Fix GSO problems in dev_hard_start_xmit()
[NET]: Fix CHECKSUM_HW GSO problems.
[TIPC]: Fix incorrect correction to discovery timer frequency computation.
[TIPC]: Get rid of dynamically allocated arrays in broadcast code.
[TIPC]: Fixed link switchover bugs
[TIPC]: Enhanced & cleaned up system messages; fixed 2 obscure memory leaks.
[TIPC]: First phase of assert() cleanup
[TIPC]: Disallow config operations that aren't supported in certain modes.
[TIPC]: Fixed memory leak in tipc_link_send() when destination is unreachable
[TIPC]: Added missing warning for out-of-memory condition
[TIPC]: Withdrawing all names from nameless port now returns success, not error
[TIPC]: Optimized argument validation done by connect().
...
Usually we don't care much about 'gcc -W' warnings, but some of us do build
kernels that way to look for problems, and then the fewer warnings we have
to wade through the better. Especially when they are very easy and
non-intrusive to clean up. Which is the case for the following warnings
spewed by drivers/usb/storage/usb.h :
drivers/usb/storage/usb.h:163: warning: `inline' is not at beginning of
+declaration
drivers/usb/storage/usb.h:166: warning: `inline' is not at beginning of
+declaration
There's also some precedence for cleaning up these warnings. I've had
a few patches merged in the past that remove exactly this class of
warnings.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Make needlessly global code static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It appears in /sys/mdX/md/dev-YYY/state
and can be set or cleared by writing 'writemostly' or '-writemostly'
respectively.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The md/dev-XXX/state file can now be written:
"faulty" simulates an error on the device
"remove" removes the device from the array (if it is not busy)
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This allows the state of an md/array to be directly controlled via sysfs and
adds the ability to stop and array without tearing it down.
Array states/settings:
clear
No devices, no size, no level
Equivalent to STOP_ARRAY ioctl
inactive
May have some settings, but array is not active
all IO results in error
When written, doesn't tear down array, but just stops it
suspended (not supported yet)
All IO requests will block. The array can be reconfigured.
Writing this, if accepted, will block until array is quiescent
readonly
no resync can happen. no superblocks get written.
write requests fail
read-auto
like readonly, but behaves like 'clean' on a write request.
clean - no pending writes, but otherwise active.
When written to inactive array, starts without resync
If a write request arrives then
if metadata is known, mark 'dirty' and switch to 'active'.
if not known, block and switch to write-pending
If written to an active array that has pending writes, then fails.
active
fully active: IO and resync can be happening.
When written to inactive array, starts with resync
write-pending (not supported yet)
clean, but writes are blocked waiting for 'active' to be written.
active-idle
like active, but no writes have been seen for a while (100msec).
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- record the 'event' count on each individual device (they
might sometimes be slightly different now)
- add a new value for 'sb_dirty': '3' means that the super
block only needs to be updated to record a clean<->dirty
transition.
- Prefer odd event numbers for dirty states and even numbers
for clean states
- Using all the above, don't update the superblock on
a spare device if the update is just doing a clean-dirty
transition. To accomodate this, a transition from
dirty back to clean might now decrement the events counter
if nothing else has changed.
The net effect of this is that spare drives will not see any IO requests
during normal running of the array, so they can go to sleep if that is what
they want to do.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When an array has a bitmap, a device can be removed and re-added and only
blocks changes since the removal (as recorded in the bitmap) will be resynced.
It should be possible to do a similar thing to arrays without bitmaps. i.e.
if a device is removed and re-added and *no* changes have been made in the
interim, then the add should not require a resync.
This patch allows that option. This means that when assembling an array one
device at a time (e.g. during device discovery) the array can be enabled
read-only as soon as enough devices are available, but extra devices can still
be added without causing a resync.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As data_disks is *less* than raid_disks, the current test here is obviously
wrong. And as the difference is already available in conf->max_degraded, it
makes much more sense to use that.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
RAID5 recently changed to RAID456
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I was experimenting with Linux SW raid today and found a spelling error when
reading the help menus... (and fly spell found more).
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The size calculation made assumtion which the new offset mode didn't
follow. This gets the size right in all cases.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix problems with new bmap based access to bitmap files.
1/ When not using a file based bitmap, attach a NULL list of buffers
to each page so the common free_buffer routine can cope.
2/ Use submit_bh to read as well as write, rather than vfs_read.
This makes read and write more symetric.
3/ sync the file before reading, to ensure that the page cache has no
dirty pages that might get written out later.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If md is asked to store a bitmap in a file, it tries to hold onto the page
cache pages for that file, manipulate them directly, and call a cocktail of
operations to write the file out. I don't believe this is a supportable
approach.
This patch changes the approach to use the same approach as swap files. i.e.
bmap is used to enumerate all the block address of parts of the file and we
write directly to those blocks of the device.
swapfile only uses parts of the file that provide a full pages at contiguous
addresses. We don't have that luxury so we have to cope with pages that are
non-contiguous in storage. To handle this we attach buffers to each page, and
store the addresses in those buffers.
With this approach the pagecache may contain data which is inconsistent with
what is on disk. To alleviate the problems this can cause, md invalidates the
pagecache when releasing the file. If the file is to be examined while the
array is active (a non-critical but occasionally useful function), O_DIRECT io
must be used. And new version of mdadm will have support for this.
This approach simplifies a lot of code:
- we no longer need to keep a list of pages which we need to wait for,
as the b_endio function can keep track of how many outstanding
writes there are. This saves a mempool.
- -EAGAIN returns from write_page are no longer possible (not sure if
they ever were actually).
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
md/bitmap modifies i_writecount of a bitmap file to make sure that no-one else
writes to it. The reverting of the change is sometimes done twice, and there
is one error path where it is omitted.
This patch tidies that up.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
bitmap_active is never called, and the BITMAP_ACTIVE flag is never users or
tested, so discard them both.
Also remove some out-of-date 'todo' comments.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
md/bitmap gets a collection of pages representing the bitmap when it
initialises the bitmap, and puts all the references when discarding the
bitmap.
It also occasionally takes extra references without any good reason, and
sometimes drops them ... though it doesn't always drop them, which can result
in a memory leak.
This patch removes the unnecessary 'get_page' calls, and the corresponding
'put_page' calls.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In particular, this means that we use 4 bits per page instead of a whole
unsigned long.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
md/bitmap has some attributes per-page. Handling of these attributes in
largely abstracted in set_page_attr and clear_page_attr. However
get_page_attr exposes the format used to store them. So prior to changing
that format, introduce test_page_attr instead of get_page_attr, and make
appropriate usage changes.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
md/bitmap currently has a separate thread to wait for writes to the bitmap
file to complete (as we cannot get a callback on that action).
However this isn't needed as bitmap_unplug is called from process context and
waits for the writeback thread to do it's work. The same result can be
achieved by doing the waiting directly in bitmap_unplug.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When "mdadm --grow /dev/mdX --bitmap=none" is used to remove a filebacked
bitmap, the bitmap was disconnected from the array, but the file wasn't closed
(until the array was stopped).
The file also wasn't closed if adding the bitmap file failed.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
... as raid5 sync_request is WAY too big.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes the needlessly global md_print_devices() static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The "industry standard" DDF format allows for a stripe/offset layout where
data is duplicated on different stripes. e.g.
A B C D
D A B C
E F G H
H E F G
(columns are drives, rows are stripes, LETTERS are chunks of data).
This is similar to raid10's 'far' mode, but not quite the same. So enhance
'far' mode with a 'far/offset' option which follows the layout of DDFs
stripe/offset.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>