linux.git/drivers/md, branch v2.6.39

raid5: fix build error, sector_t usage

2011-04-21T17:00:00+00:00

Change  from unsigned long long to sector_t.
This matches its source field.

  ERROR: "__udivdi3" [drivers/md/raid456.ko] undefined!

Signed-off-by: Randy Dunlap 
Signed-off-by: Linus Torvalds

md: Cleanup after raid45->raid0 takeover

2011-04-20T05:39:53+00:00

Problem:
After raid4->raid0 takeover operation, another takeover operation
(e.g raid0->raid10) results "kernel oops".
Root cause:
Variables 'degraded' in mddev structure is not cleared
on raid45->raid0 takeover.

This patch reset this variable.

Signed-off-by: Krzysztof Wojcik 
Signed-off-by: NeilBrown

md: Fix dev_sectors on takeover from raid0 to raid4/5

2011-04-20T05:38:18+00:00

A raid0 array doesn't set 'dev_sectors' as each device might
contribute a different number of sectors.
So when converting to a RAID4 or RAID5 we need to set dev_sectors
as they need the number.
We have already verified that in fact all devices do contribute
the same number of sectors, so use that number.

Signed-off-by: NeilBrown

md/raid5: remove setting of ->queue_lock

2011-04-20T05:38:07+00:00

We previously needed to set ->queue_lock to match the raid5
device_lock so we could safely use queue_flag_* operations (e.g. for
plugging). which test the ->queue_lock is in fact locked.

However that need has completely gone away and is unlikely to come
back to remove this now-pointless setting.

Signed-off-by: NeilBrown

md: fix up raid1/raid10 unplugging.

2011-04-18T08:25:43+00:00

We just need to make sure that an unplug event wakes up the md
thread, which is exactly what mddev_check_plugged does.

Also remove some plug-related code that is no longer needed.

Signed-off-by: NeilBrown

md: incorporate new plugging into raid5.

2011-04-18T08:25:43+00:00

In raid5 plugging is used for 2 things:
 1/ collecting writes that require a bitmap update
 2/ collecting writes in the hope that we can create full
    stripes - or at least more-full.

We now release these different sets of stripes when plug_cnt
is zero.

Also in make_request, we call mddev_check_plug to hopefully increase
plug_cnt, and wake up the thread at the end if plugging wasn't
achieved for some reason.

Signed-off-by: NeilBrown

md: provide generic support for handling unplug callbacks.

2011-04-18T08:25:42+00:00

When an md device adds a request to a queue, it can call
mddev_check_plugged.
If this succeeds then we know that the md thread will be woken up
shortly, and ->plug_cnt will be non-zero until then, so some
processing can be delayed.

If it fails, then no unplug callback is expected and the make_request
function needs to do whatever is required to make the request happen.

Signed-off-by: NeilBrown

md - remove old plugging code.

2011-04-18T08:25:42+00:00

md has some plugging infrastructure for RAID5 to use because the
normal plugging infrastructure required a 'request_queue', and when
called from dm, RAID5 doesn't have one of those available.

This relied on the ->unplug_fn callback which doesn't exist any more.

So remove all of that code, both in md and raid5.  Subsequent patches
with restore the plugging functionality.

Signed-off-by: NeilBrown

md/dm - remove remains of plug_fn callback.

2011-04-18T08:25:41+00:00

Now that unplugging is done differently, the unplug_fn callback is
never called, so it can be completely discarded.

Signed-off-by: NeilBrown

md: use new plugging interface for RAID IO.

2011-04-18T08:25:41+00:00

md/raid submits a lot of IO from the various raid threads.
So adding start/finish plug calls to those so that some
plugging happens.

Signed-off-by: NeilBrown