This adds real clock support to Calxeda Highbank SOC using the common
clock infrastructure.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
[mturquette@linaro.org: fixed up invalid writes to const struct member]
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Add support for DT "fixed-clock" binding to the common fixed rate clock
support.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
[Rob Herring] Rework and move into common clock infrastructure
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Based on work 1st by Ben Herrenschmidt and Jeremy Kerr, then by Grant
Likely, this patch adds support to clk_get to allow drivers to retrieve
clock data from the device tree.

Platforms scan for clocks in DT with of_clk_init and a match table, and
the register a provider through of_clk_add_provider. The provider's
clk_src_get function will be called when a device references the
provider's OF node for a clock reference.

v6 (Rob Herring):
    - Return error values instead of NULL to match clock framework
      expectations

v5 (Rob Herring):
    - Move from drivers/of into common clock subsystem
    - Squashed "dt/clock: add a simple provider get function" and
      "dt/clock: add function to get parent clock name"
    - Rebase to 3.4-rc1
    - Drop CONFIG_OF_CLOCK and just use CONFIG_OF
    - Add missing EXPORT_SYMBOL to various functions
    - s/clock-output-name/clock-output-names/
    - Define that fixed-clock binding is a single output

v4 (Rob Herring):
    - Rework for common clk subsystem
    - Add of_clk_get_parent_name function

v3: - Clarified documentation

v2: - fixed errant ';' causing compile error
    - Editorial fixes from Shawn Guo
    - merged in adding lookup to clkdev
    - changed property names to match established convention. After
      working with the binding a bit it really made more sense to follow the
      lead of 'reg', 'gpios' and 'interrupts' by making the input simply
      'clocks' & 'clock-names' instead of 'clock-input-*', and to only use
      clock-output* for the producer nodes. (Sorry Shawn, this will mean
      you need to change some code, but it should be trivial)
    - Add ability to inherit clocks from parent nodes by using an empty
      'clock-ranges' property.  Useful for busses.  I could use some feedback
      on the new property name, 'clock-ranges' doesn't feel right to me.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Reviewed-by: NShawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

This converts the Integrator platform to use common clock
and the ICST driver. Since from this point not all ARM
reference platforms use the clock, we define
CONFIG_PLAT_VERSATILE_CLOCK and select it for all platforms
except the Integrator.

Open issue: I could not use the .init_early() field of the
machine descriptor to initialize the clocks, but had to
move them to .init_irq(), so presumably .init_early() is
so early that common clock is not up, and .init_machine()
is too late since it's needed for the clockevent/clocksource
initialization. Any suggestions on how to solve this is
very welcome.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
[mturquette@linaro.org: use 'select' instead of versatile Kconfig]
Signed-off-by: NMike Turquette <mturquette@linaro.org>

The ICST307 VCO clock has a shared driver in the ARM
architecture. This patch provides a wrapper into the common
clock framework so we can use the implementation in the
ARM architecture without duplicating the code until all
ARM platforms using this VCO are moved over. At that point
we can merge the driver from the ARM platform into the
generic file altogether.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mike Turquette <mturquette@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
[mturquette@linaro.org: removed versatile Kconfig]
Signed-off-by: NMike Turquette <mturquette@linaro.org>

This converts the U300 clock implementation over to use the common
struct clk and moves the implementation down into drivers/clk.
Since VCO isn't used in tree it was removed, it's not hard to
put it back in if need be.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
[mturquette@linaro.org: trivial Makefile conflict]
Signed-off-by: NMike Turquette <mturquette@linaro.org>

caching parent clocks makes sense only when a clock has more
than one parent (mux clocks).
Avoid doing this for every other clock.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
[mturquette@linaro.org: removed extra parentheses]
Signed-off-by: NMike Turquette <mturquette@linaro.org>

The WM831x and WM832x series of PMICs contain a flexible clocking
subsystem intended to provide always on and system core clocks.  It
features:

- A 32.768kHz crystal oscillator which can optionally be used to pass
  through an externally generated clock.
- A FLL which can be clocked from either the 32.768kHz oscillator or
  the CLKIN pin.
- A CLKOUT pin which can bring out either the oscillator or the FLL
  output.
- The 32.768kHz clock can also optionally be brought out on the GPIO
  pins of the device.

This driver fully supports the 32.768kHz oscillator and CLKOUT.  The FLL
is supported only in AUTO mode, the full flexibility of the FLL cannot
currently be used.

Due to a lack of access to systems where the core SoC has been converted
to use the generic clock API this driver has been compile tested only.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Most platforms end up using a mix of basic clock types and
some which use clk_hw_foo struct for filling in custom platform
information when the clocks don't fit into basic types supported.

In platform code, its useful to know if a clock is using a basic
type or clk_hw_foo, which helps platforms know if they can
safely use to_clk_hw_foo to derive the clk_hw_foo pointer from
clk_hw.

Mark all basic clocks with a CLK_IS_BASIC flag.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Some divider clks do not have any obvious relationship
between the divider and the value programmed in the
register. For instance, say a value of 1 could signify divide
by 6 and a value of 2 could signify divide by 4 etc.
Also there are dividers where not all values possible
based on the bitfield width are valid. For instance
a 3 bit wide bitfield can be used to program a value
from 0 to 7. However its possible that only 0 to 4
are valid values.

All these cases need the platform code to pass a simple
table of divider/value tuple, so the framework knows
the exact value to be written based on the divider
calculation and can also do better error checking.

This patch adds support for such rate table based
dividers and as part of the support adds a new
registration function 'clk_register_divider_table()'
and a new macro for static definition
'DEFINE_CLK_DIVIDER_TABLE'.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Quite often dividers and the value programmed in the
register have a relation of 'power of two', something like
value	div
0	1
1	2
2	4
3	8...

Add support for such dividers as part of clk-divider.

The clk-divider flag 'CLK_DIVIDER_POWER_OF_TWO' should be used
to define such clocks.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Based upon Alan's patch from Coverity scan id 793583, these debug
messages in qlt_async_event() should be starting from byte 0, which is
always the Asynchronous Event Status Code from the parent switch statement.

Also, rename reason_code -> login_code following the language used in
2500 FW spec for Port Database Changed (0x8014) -> Port Database Changed
Event Mailbox Register for mailbox[2].
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Cc: Chad Dupuis <chad.dupuis@qlogic.com>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Use rcu_dereference_protected to tell rcu that the ft_lport_lock
is held during ft_lport_create. This resolved "suspicious RCU usage"
warnings when debugging options are turned on.
Signed-off-by: NMark Rustad <mark.d.rustad@intel.com>
Tested-by: NRoss Brattain <ross.b.brattain@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The intent here was clearly to set result to true if the 0x40000000 flag
was set.  But instead there was a | vs & typo and we always set result
to true.

Artem: check the spec at
wiki.laptop.org/images/5/5c/88ALP01_Datasheet_July_2007.pdf
and this fix looks correct.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

SSP0 and SSP1 use ref_io0 which has decreased frequency. Expand
the frequency fix for ref_io1 to get SSP2 and SSP3 to work.
Signed-off-by: NLauri Hintsala <lauri.hintsala@bluegiga.com>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

Since commit 1c6c6952 ("genirq: Reject bogus threaded irq requests")
threaded IRQs without a primary handler need to be requested with
IRQF_ONESHOT, otherwise the request will fail. This patch adds the
IRQF_ONESHOT to input drivers where it is missing. Not modified by
this patch are those drivers where the requested IRQ will always be a
nested IRQ (e.g. because it's part of an MFD), since for this special
case IRQF_ONESHOT is not required to be specified when requesting the
IRQ.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

With commit 49dca5ae I introduced
a bug (visible if CONFIG_PROVE_RCU is enabled) which occures when a panic
has happened:

[ 1526.520230] ===============================
[ 1526.520230] [ INFO: suspicious RCU usage. ]
[ 1526.520230] 3.5.0-rc1+ #12 Not tainted
[ 1526.520230] -------------------------------
[ 1526.520230] /c/kernel-tests/mm/include/linux/rcupdate.h:436 Illegal context switch in RCU read-side critical section!
[ 1526.520230]
[ 1526.520230] other info that might help us debug this:
[ 1526.520230]
[ 1526.520230]
[ 1526.520230] rcu_scheduler_active = 1, debug_locks = 0
[ 1526.520230] 3 locks held by net.agent/3279:
[ 1526.520230]  #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff82f85962>] do_page_fault+0x193/0x390
[ 1526.520230]  #1:  (panic_lock){+.+...}, at: [<ffffffff82ed2830>] panic+0x37/0x1d3
[ 1526.520230]  #2:  (rcu_read_lock){.+.+..}, at: [<ffffffff810b9b28>] rcu_lock_acquire+0x0/0x29
[ 1526.520230]
[ 1526.520230] stack backtrace:
[ 1526.520230] Pid: 3279, comm: net.agent Not tainted 3.5.0-rc1+ #12
[ 1526.520230] Call Trace:
[ 1526.520230]  [<ffffffff810e1570>] lockdep_rcu_suspicious+0x109/0x112
[ 1526.520230]  [<ffffffff810bfe3a>] rcu_preempt_sleep_check+0x45/0x47
[ 1526.520230]  [<ffffffff810bfe5a>] __might_sleep+0x1e/0x19a
[ 1526.520230]  [<ffffffff82f8010e>] down_write+0x26/0x81
[ 1526.520230]  [<ffffffff8276a966>] led_trigger_unregister+0x1f/0x9c
[ 1526.520230]  [<ffffffff8276def5>] heartbeat_reboot_notifier+0x15/0x19
[ 1526.520230]  [<ffffffff82f85bf5>] notifier_call_chain+0x96/0xcd
[ 1526.520230]  [<ffffffff82f85cba>] __atomic_notifier_call_chain+0x8e/0xff
[ 1526.520230]  [<ffffffff81094b7c>] ? kmsg_dump+0x37/0x1eb
[ 1526.520230]  [<ffffffff82f85d3f>] atomic_notifier_call_chain+0x14/0x16
[ 1526.520230]  [<ffffffff82ed28e1>] panic+0xe8/0x1d3
[ 1526.520230]  [<ffffffff811473e2>] out_of_memory+0x15d/0x1d3

So in case of a panic, now just turn of the LED. Other approaches like
scheduling a work to unregister the trigger aren't working because there
isn't much which still runs after a panic occured (except timers).
Signed-off-by: NAlexander Holler <holler@ahsoftware.de>
Signed-off-by: NBryan Wu <bryan.wu@canonical.com>

build error introduced by commit b357f04a

That function doesn't get extra args until a later patch.  Bother.

Reported-by: Fengguang Wu <wfg@linux.intel.com> 
Reported-by: NSimon Kirby <sim@hostway.ca>
Reported-by: NTobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: NNeilBrown <neilb@suse.de>

In commit 070ad7e7 ("floppy: convert to delayed work and
single-thread wq") the 'fd_timeout' timer was converted to a delayed
work.  However, the "del_timer(&fd_timeout)" was lost in the process,
and any previous pending timeouts would stay active when we then
re-queued the timeout.

This resulted in the floppy probe sequence having a (stale) 20s timeout
rather than the intended 3s timeout, and thus made booting with the
floppy driver (but no actual floppy controller) take much longer than it
should.

Of course, there's little reason for most people to compile the floppy
driver into the kernel at all, which is why most people never noticed.

Canceling the delayed work where we used to do the del_timer() fixes the
issue, and makes the floppy probing use the proper new timeout instead.
The three second timeout is still very wasteful, but better than the 20s
one.
Reported-and-tested-by: NAndi Kleen <ak@linux.intel.com>
Reported-and-tested-by: NCalvin Walton <calvin.walton@kepstin.ca>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The below commit introduced a bug in __clk_set_parent()
which could cause it to *skip* the parent validation
which makes sure the parent passed to the api is a valid
one.

    commit 7975059d
    Author: Rajendra Nayak <rnayak@ti.com>
    Date:   Wed Jun 6 14:41:31 2012 +0530

        clk: Allow late cache allocation for clk->parents

This was identified by the following compiler warning..

    drivers/clk/clk.c: In function '__clk_set_parent':
    drivers/clk/clk.c:1083:5: warning: 'i' may be used uninitialized in this function [-Wuninitialized]

.. as reported by Marc Kleine-Budde.

There were various options discussed on how to fix this, one
being initing 'i' to clk->num_parents, but the below approach
was found to be more appropriate as it also makes the 'parent
validation' code simpler to read.
Reported-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>
Cc: stable@kernel.org

If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and memory is fragmented and a
sufficiently-large metadata device is used in a thin pool then the space
map checker will fail to allocate the memory it requires.

Switch from kmalloc to vmalloc to allow larger virtually contiguous
allocations for the space map checker's internal count arrays.
Reported-by: NVivek Goyal <vgoyal@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and dm_sm_checker_create()
fails, dm_tm_create_internal() would still return success even though it
cleaned up all resources it was supposed to have created.  This will
lead to a kernel crash:

general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
...
RIP: 0010:[<ffffffff81593659>]  [<ffffffff81593659>] dm_bufio_get_block_size+0x9/0x20
Call Trace:
  [<ffffffff81599bae>] dm_bm_block_size+0xe/0x10
  [<ffffffff8159b8b8>] sm_ll_init+0x78/0xd0
  [<ffffffff8159c1a6>] sm_ll_new_disk+0x16/0xa0
  [<ffffffff8159c98e>] dm_sm_disk_create+0xfe/0x160
  [<ffffffff815abf6e>] dm_pool_metadata_open+0x16e/0x6a0
  [<ffffffff815aa010>] pool_ctr+0x3f0/0x900
  [<ffffffff8158d565>] dm_table_add_target+0x195/0x450
  [<ffffffff815904c4>] table_load+0xe4/0x330
  [<ffffffff815917ea>] ctl_ioctl+0x15a/0x2c0
  [<ffffffff81591963>] dm_ctl_ioctl+0x13/0x20
  [<ffffffff8116a4f8>] do_vfs_ioctl+0x98/0x560
  [<ffffffff8116aa51>] sys_ioctl+0x91/0xa0
  [<ffffffff81869f52>] system_call_fastpath+0x16/0x1b

Fix the space map checker code to return an appropriate ERR_PTR and have
dm_sm_disk_create() and dm_tm_create_internal() check for it with
IS_ERR.
Reported-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

Cleanup the shadow table before destroying the transaction manager.

Reference: leak was identified with kmemleak when running
test_discard_random_sectors in the thinp-test-suite.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

Userland sometimes sees a corrupt metadata block if metadata is changing
rapidly when a metadata snapshot is reserved for userland,  To make the
problem go away, commit before we take the metadata snapshot (which is a
sensible thing to do anyway).

The checksums mean userland spots this corruption immediately so there's
no risk of acting on incorrect data.  No corruption exists from the
kernel's point of view, and thin_check passes after pool shutdown.

I believe this is to do with shared blocks at the first level of the
{device, mapping} btree.  Prior to the metadata-snap support no sharing
at this level was possible, so this patch is only required after commit
cc8394d8 ("dm thin: provide userspace
access to pool metadata").
Signed-off-by: NJoe Thornber <ejt@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

Especially vesafb likes to map everything as uc- (yikes), and if that
mapping hangs around still while we try to map the gtt as wc the
kernel will downgrade our request to uc-, resulting in abyssal
performance.

Unfortunately we can't do this as early as readon does (i.e. as the
first thing we do when initializing the hw) because our fb/mmio space
region moves around on a per-gen basis. So I've had to move it below
the gtt initialization, but that seems to work, too. The important
thing is that we do this before we set up the gtt wc mapping.

Now an altogether different question is why people compile their
kernels with vesafb enabled, but I guess making things just work isn't
bad per se ...

v2:
- s/radeondrmfb/inteldrmfb/
- fix up error handling

v3: Kill #ifdef X86, this is Intel after all. Noticed by Ben Widawsky.

v4: Jani Nikula complained about the pointless bool primary
initialization.

v5: Don't oops if we can't allocate, noticed by Chris Wilson.

v6: Resolve conflicts with agp rework and fixup whitespace.

This is commit e188719a in drm-next.

Backport to 3.5 -fixes queue requested by Dave Airlie - due to grub
using vesa on fedora their initrd seems to load vesafb before loading
the real kms driver. So tons more people actually experience a
dead-slow gpu. Hence also the Cc: stable.

Cc: stable@vger.kernel.org
Reported-and-tested-by: N"Kilarski, Bernard R" <bernard.r.kilarski@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

When a monitor EDID doesn't give the preferred bit, driver assumes
that the mode with the higest resolution and rate is the preferred
mode.  Meanwhile the recent changes for allowing more modes in the
GFT/CVT ranges give actually more modes, and some modes may be over
the native size.  Thus such a mode would be picked up as the preferred
mode although it's no native resolution.

For avoiding such a problem, this patch limits the addition of
inferred modes by checking not to be greater than other modes.
Also, it checks the duplicated mode entry at the same time.
Reviewed-by: NAdam Jackson <ajax@redhat.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

In gem idle/busy ioctl the radeon object was derefenced after
drm_gem_object_unreference_unlocked which in case the object
have been destroyed lead to use of a possibly free pointer with
possibly wrong data.
Signed-off-by: NJerome Glisse <jglisse@redhat.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

The value returned by "mddev_check_plug" is only valid until the
next 'schedule' as that will unplug things.  This could happen at any
call to mempool_alloc.
So just calling mddev_check_plug at the start doesn't really make
sense.

So call it just before, or just after, queuing things for the thread.
As the action that happens at unplug is to wake the thread, this makes
lots of sense.
If we cannot add a plug (which requires a small GFP_ATOMIC alloc) we
wake thread immediately.

RAID5 is a bit different.  Requests are queued for the thread and the
thread is woken by release_stripe.  So we don't need to wake the
thread on failure.
However the thread doesn't perform certain actions when there is any
active plug, so it is important to install a plug before waking the
thread.  So for RAID5 we install the plug *before* queuing the request
and waking the thread.

Without this patch it is possible for raid1 or raid10 to queue a
request without then waking the thread, resulting in the array locking
up.

Also change raid10 to only flush_pending_write when there are not
active plugs, just like raid1.

This patch is suitable for 3.0 or later.  I plan to submit it to
-stable, but I'll like to let it spend a few weeks in mainline
first to be sure it is completely safe.
Signed-off-by: NNeilBrown <neilb@suse.de>

We currently only allow a device to be re-added if it appear to be
in-sync.  This is overly restrictive as it may be desirable to re-add
a device that is in the middle of recovery.

So remove the test for "InSync" - the test on rdev->raid_disk is
sufficient to ensure that the re-add will succeed.
Reported-by: NAlexander Lyakas <alex.bolshoy@gmail.com>
Tested-by: NAlexander Lyakas <alex.bolshoy@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

When we added hot_replace we doubled the number of devices
that could be in a RAID1 array.  So we doubled how far read_balance
would search.  Unfortunately we didn't double the point at which
it looped back to the beginning - so it effectively loops over
all non-replacement disks twice.
This doesn't cause bad behaviour, but it pointless and means we
never read from replacement devices.
Signed-off-by: NNeilBrown <neilb@suse.de>

There isn't locking setting STRIPE_DELAYED and STRIPE_PREREAD_ACTIVE bits, but
the two bits have relationship. A delayed stripe can be moved to hold list only
when preread active stripe count is below IO_THRESHOLD. If a stripe has both
the bits set, such stripe will be in delayed list and preread count not 0,
which will make such stripe never leave delayed list.
Signed-off-by: NShaohua Li <shli@fusionio.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

We may not be able to fix a bad block if:
 - the array is degraded
 - the over-write fails.

In these cases we currently eject the device, but we should
record a bad block if possible.
Signed-off-by: Nmajianpeng <majianpeng@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

Having the 'name' arg optional and defaulting to the current
personality name is no necessary and leads to errors, as when
changing the level of an array we can end up using the
name of the old level instead of the new one.

So make it non-optional and always explicitly pass the name
of the level that the array will be.
Reported-by: Nmajianpeng <majianpeng@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

commit 58c54fcc
     md/raid10: handle further errors during fix_read_error better.

in 3.1 added "r10_sync_page_io" which takes an IO size in sectors.
But we were passing the IO size in bytes!!!
This resulting in bio_add_page failing, and empty request being sent
down, and a consequent BUG_ON in scsi_lib.

[fix missing space in error message at same time]

This fix is suitable for 3.1.y and later.

Cc: stable@vger.kernel.org
Reported-by: NChristian Balzer <chibi@gol.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

commit 43220aa0
    md/raid5: fix a hang on device failure.

fixed a hang, but introduced a refcounting in-balance so
that if the presence of bad-blocks ever caused an rdev to
be 'blocked' we would increment the refcount on the rdev and
never decrement it.

So added the needed rdev_dec_pending when md_wait_for_blocked_rdev
is not called.
Reported-by: Nmajianpeng <majianpeng@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

Add blk_plug in sync_thread will increase the performance of sync.
Because sync_thread did not blk_plug,so when raid sync, the bio merge
not well.

Testing environment:
SATA controller: Intel Corporation 82801JI (ICH10 Family) SATA AHCI
Controller.
OS:Linux xxx 3.5.0-rc2+ #340 SMP Tue Jun 12 09:00:25 CST 2012
x86_64 x86_64 x86_64 GNU/Linux.
RAID5: four ST31000524NS disk.

Without blk_plug:recovery speed about 63M/Sec;
Add blk_plug:recovery speed about 120M/Sec.

Using blktrace:
blktrace -d /dev/sdb -w 60  -o -|blkparse -i -

without blk_plug:
Total (8,16):
 Reads Queued:      309811,     1239MiB	 Writes Queued:           0,        0KiB
 Read Dispatches:   283583,     1189MiB	 Write Dispatches:        0,        0KiB
 Reads Requeued:         0		 Writes Requeued:         0
 Reads Completed:   273351,     1149MiB	 Writes Completed:        0,        0KiB
 Read Merges:        23533,    94132KiB	 Write Merges:            0,        0KiB
 IO unplugs:             0        	 Timer unplugs:           0

add blk_plug:
Total (8,16):
 Reads Queued:      428697,     1714MiB	 Writes Queued:           0,        0KiB
 Read Dispatches:     3954,     1714MiB	 Write Dispatches:        0,        0KiB
 Reads Requeued:         0		 Writes Requeued:         0
 Reads Completed:     3956,     1715MiB	 Writes Completed:        0,        0KiB
 Read Merges:       424743,     1698MiB	 Write Merges:            0,        0KiB
 IO unplugs:             0        	 Timer unplugs:        3384

The ratio of merge will be markedly increased.
Signed-off-by: Nmajianpeng <majianpeng@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

In ops_run_io(), the call to md_wait_for_blocked_rdev will decrement
nr_pending so we lose the reference we hold on the rdev.
So atomic_inc it first to maintain the reference.

This bug was introduced by commit  73e92e51
    md/raid5.  Don't write to known bad block on doubtful devices.

which appeared in 3.0, so patch is suitable for stable kernels since
then.

Cc: stable@vger.kernel.org
Signed-off-by: Nmajianpeng <majianpeng@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

In chunk_aligned_read() we are adding data_offset before calling
is_badblock.  But is_badblock also adds data_offset, so that is bad.

So move the addition of data_offset to after the call to
is_badblock.

This bug was introduced by commit 31c176ec
     md/raid5: avoid reading from known bad blocks.
which first appeared in 3.0.  So that patch is suitable for any
-stable kernel from 3.0.y onwards.  However it will need minor
revision for most of those (as the comment didn't appear until
recently).

Cc: stable@vger.kernel.org
Signed-off-by: Nmajianpeng <majianpeng@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

If a RAID5 has both a failed device and a device marked as
'WantReplacement', then we should preferentially replace the failed
device.
However the current code replaces whichever is found first.
So split into 2 loops, check fail failed/missing first, and only check
for WantReplacement if nothing is failed or missing.
Reported-by: Nmajianpeng <majianpeng@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

If a RAID10 has an odd number of chunks - as might happen when there
are an odd number of devices - the last chunk has no pair and so is
not mirrored.  We don't store data there, but when recovering the last
device in an array we retry to recover that last chunk from a
non-existent location.  This results in an error, and the recovery
aborts.

When we get to that last chunk we should just stop - there is nothing
more to do anyway.

This bug has been present since the introduction of RAID10, so the
patch is appropriate for any -stable kernel.

Cc: stable@vger.kernel.org
Reported-by: NChristian Balzer <chibi@gol.com>
Tested-by: NChristian Balzer <chibi@gol.com>
Signed-off-by: NNeilBrown <neilb@suse.de>