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  1. 30 Dec, 2011 12 commits
  3. 24 Dec, 2011 3 commits
  5. 23 Dec, 2011 14 commits
  7. 22 Dec, 2011 11 commits
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://neil.brown.name/md · ad1fca20
      Linus Torvalds authored 
      * 'for-linus' of git://neil.brown.name/md:
  md/bitmap: It is OK to clear bits during recovery.
  md: don't give up looking for spares on first failure-to-add
  md/raid5: ensure correct assessment of drives during degraded reshape.
  md/linear: fix hot-add of devices to linear arrays.
      ad1fca20
    • NeilBrown's avatar
      md/bitmap: It is OK to clear bits during recovery. · 961902c0
      NeilBrown authored 
      commit d0a4bb49 introduced a
regression which is annoying but fairly harmless.

When writing to an array that is undergoing recovery (a spare
in being integrated into the array), writing to the array will
set bits in the bitmap, but they will not be cleared when the
write completes.

For bits covering areas that have not been recovered yet this is not a
problem as the recovery will clear the bits.  However bits set in
already-recovered region will stay set and never be cleared.
This doesn't risk data integrity.  The only negatives are:
 - next time there is a crash, more resyncing than necessary will
   be done.
 - the bitmap doesn't look clean, which is confusing.

While an array is recovering we don't want to update the
'events_cleared' setting in the bitmap but we do still want to clear
bits that have very recently been set - providing they were written to
the recovering device.

So split those two needs - which previously both depended on 'success'
and always clear the bit of the write went to all devices.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      961902c0
    • NeilBrown's avatar
      md: don't give up looking for spares on first failure-to-add · 60fc1370
      NeilBrown authored 
      Before performing a recovery we try to remove any spares that
might not be working, then add any that might have become relevant.

Currently we abort on the first spare that cannot be added.
This is a false optimisation.
It is conceivable that - depending on rules in the personality - a
subsequent spare might be accepted.
Also the loop does other things like count the available spares and
reset the 'recovery_offset' value.

If we abort early these might not happen properly.

So remove the early abort.

In particular if you have an array what is undergoing recovery and
which has extra spares, then the recovery may not restart after as
reboot as the could of 'spares' might end up as zero.
Reported-by: default avatarAnssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      60fc1370
    • NeilBrown's avatar
      md/raid5: ensure correct assessment of drives during degraded reshape. · 30d7a483
      NeilBrown authored 
      While reshaping a degraded array (as when reshaping a RAID0 by first
converting it to a degraded RAID4) we currently get confused about
which devices are in_sync.  In most cases we get it right, but in the
region that is being reshaped we need to treat non-failed devices as
in-sync when we have the data but haven't actually written it out yet.
Reported-by: default avatarAdam Kwolek <adam.kwolek@intel.com>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      30d7a483
    • NeilBrown's avatar
      md/linear: fix hot-add of devices to linear arrays. · 09cd9270
      NeilBrown authored 
      commit d70ed2e4
broke hot-add to a linear array.
After that commit, metadata if not written to devices until they
have been fully integrated into the array as determined by
saved_raid_disk.  That patch arranged to clear that field after
a recovery completed.

However for linear arrays, there is no recovery - the integration is
instantaneous.  So we need to explicitly clear the saved_raid_disk
field.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      09cd9270
    • David S. Miller's avatar
      sparc64: Fix MSIQ HV call ordering in pci_sun4v_msiq_build_irq(). · 7cc85833
      David S. Miller authored 
      This silently was working for many years and stopped working on
Niagara-T3 machines.

We need to set the MSIQ to VALID before we can set it's state to IDLE.

On Niagara-T3, setting the state to IDLE first was causing HV_EINVAL
errors.  The hypervisor documentation says, rather ambiguously, that
the MSIQ must be "initialized" before one can set the state.

I previously understood this to mean merely that a successful setconf()
operation has been performed on the MSIQ, which we have done at this
point.  But it seems to also mean that it has been set VALID too.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      7cc85833
    • Linus Torvalds's avatar
      Merge branch 'usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb · b3b1b70e
      Linus Torvalds authored 
      * 'usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: Fix usb/isp1760 build on sparc
  usb: gadget: epautoconf: do not change number of streams
  usb: dwc3: core: fix cached revision on our structure
  usb: musb: fix reset issue with full speed device
      b3b1b70e
    • Linus Torvalds's avatar
      Merge branch 'upstream-linus' of git://github.com/jgarzik/libata-dev · abe8809c
      Linus Torvalds authored 
      * 'upstream-linus' of git://github.com/jgarzik/libata-dev:
  pata_of_platform: Add missing CONFIG_OF_IRQ dependency.
      abe8809c
    • David Miller's avatar
      pata_of_platform: Add missing CONFIG_OF_IRQ dependency. · 19d40dca
      David Miller authored 
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
      19d40dca
    • Stephen Rothwell's avatar
      ipv4: using prefetch requires including prefetch.h · b9eda06f
      Stephen Rothwell authored 
      Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Acked-by: default avatarDavid Miller <davem@davemloft.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b9eda06f
    • Srivatsa S. Bhat's avatar
      VFS: Fix race between CPU hotplug and lglocks · e30e2fdf
      Srivatsa S. Bhat authored 
      Currently, the *_global_[un]lock_online() routines are not at all synchronized
with CPU hotplug. Soft-lockups detected as a consequence of this race was
reported earlier at https://lkml.org/lkml/2011/8/24/185. (Thanks to Cong Meng
for finding out that the root-cause of this issue is the race condition
between br_write_[un]lock() and CPU hotplug, which results in the lock states
getting messed up).

Fixing this race by just adding {get,put}_online_cpus() at appropriate places
in *_global_[un]lock_online() is not a good option, because, then suddenly
br_write_[un]lock() would become blocking, whereas they have been kept as
non-blocking all this time, and we would want to keep them that way.

So, overall, we want to ensure 3 things:
1. br_write_lock() and br_write_unlock() must remain as non-blocking.
2. The corresponding lock and unlock of the per-cpu spinlocks must not happen
   for different sets of CPUs.
3. Either prevent any new CPU online operation in between this lock-unlock, or
   ensure that the newly onlined CPU does not proceed with its corresponding
   per-cpu spinlock unlocked.

To achieve all this:
(a) We introduce a new spinlock that is taken by the *_global_lock_online()
    routine and released by the *_global_unlock_online() routine.
(b) We register a callback for CPU hotplug notifications, and this callback
    takes the same spinlock as above.
(c) We maintain a bitmap which is close to the cpu_online_mask, and once it is
    initialized in the lock_init() code, all future updates to it are done in
    the callback, under the above spinlock.
(d) The above bitmap is used (instead of cpu_online_mask) while locking and
    unlocking the per-cpu locks.

The callback takes the spinlock upon the CPU_UP_PREPARE event. So, if the
br_write_lock-unlock sequence is in progress, the callback keeps spinning,
thus preventing the CPU online operation till the lock-unlock sequence is
complete. This takes care of requirement (3).

The bitmap that we maintain remains unmodified throughout the lock-unlock
sequence, since all updates to it are managed by the callback, which takes
the same spinlock as the one taken by the lock code and released only by the
unlock routine. Combining this with (d) above, satisfies requirement (2).

Overall, since we use a spinlock (mentioned in (a)) to prevent CPU hotplug
operations from racing with br_write_lock-unlock, requirement (1) is also
taken care of.

By the way, it is to be noted that a CPU offline operation can actually run
in parallel with our lock-unlock sequence, because our callback doesn't react
to notifications earlier than CPU_DEAD (in order to maintain our bitmap
properly). And this means, since we use our own bitmap (which is stale, on
purpose) during the lock-unlock sequence, we could end up unlocking the
per-cpu lock of an offline CPU (because we had locked it earlier, when the
CPU was online), in order to satisfy requirement (2). But this is harmless,
though it looks a bit awkward.
Debugged-by: default avatarCong Meng <mc@linux.vnet.ibm.com>
Signed-off-by: default avatarSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
      e30e2fdf
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