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  1. 22 Dec, 2011 8 commits
    • Steven Rostedt's avatar
      md: Fix userspace free_pages() macro · 38059ec2
      Steven Rostedt authored 
      While using etags to find free_pages(), I stumbled across this debug
definition of free_pages() that is to be used while debugging some raid
code in userspace. The __get_free_pages() allocates the correct size,
but the free_pages() does not match. free_pages(), like
__get_free_pages(), takes an order and not a size.
Acked-by: default avatarH. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      38059ec2
    • NeilBrown's avatar
      md/raid5: be more thorough in calculating 'degraded' value. · 908f4fbd
      NeilBrown authored 
      When an array is being reshaped to change the number of devices,
the two halves can be differently degraded.  e.g. one could be
missing a device and the other not.

So we need to be more careful about calculating the 'degraded'
attribute.

Instead of just inc/dec at appropriate times, perform a full
re-calculation examining both possible cases.  This doesn't happen
often so it not a big cost, and we already have most of the code to
do it.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      908f4fbd
    • NeilBrown's avatar
      md/bitmap: daemon_work cleanup. · 2e61ebbc
      NeilBrown authored 
      We have a variable 'mddev' in this function, but repeatedly get the
same value by dereferencing bitmap->mddev.
There is room for simplification here...
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      2e61ebbc
    • NeilBrown's avatar
      md: allow non-privileged uses to GET_*_INFO about raid arrays. · 506c9e44
      NeilBrown authored 
      The info is already available in /proc/mdstat and /sys/block in
an accessible form so there is no point in putting a road-block in
the ioctl for information gathering.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      506c9e44
    • 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
  3. 09 Dec, 2011 1 commit
  5. 08 Dec, 2011 5 commits
    • NeilBrown's avatar
      md/raid5: never wait for bad-block acks on failed device. · 9283d8c5
      NeilBrown authored 
      Once a device is failed we really want to completely ignore it.
It should go away soon anyway.

In particular the presence of bad blocks on it should not cause us to
block as we won't be trying to write there anyway.

So as soon as we can check if a device is Faulty, do so and pretend
that it is already gone if it is Faulty.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      9283d8c5
    • NeilBrown's avatar
      md: ensure new badblocks are handled promptly. · 8bd2f0a0
      NeilBrown authored 
      When we mark blocks as bad we need them to be acknowledged by the
metadata handler promptly.

For an in-kernel metadata handler that was already being done.  But
for an external metadata handler we need to alert it of the change by
sending a notification through the sysfs file.  This adds that
notification.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      8bd2f0a0
    • NeilBrown's avatar
      md: bad blocks shouldn't cause a Blocked status on a Faulty device. · 52c64152
      NeilBrown authored 
      Once a device is marked Faulty the badblocks - whether acknowledged or
not - become irrelevant.  So they shouldn't cause the device to be
marked as Blocked.

Without this patch, a process might write "-blocked" to clear the
Blocked status, but while that will correctly fail the device, it
won't remove the apparent 'blocked' status.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      52c64152
    • NeilBrown's avatar
      md: take a reference to mddev during sysfs access. · af8a2434
      NeilBrown authored 
      
When we are accessing an mddev via sysfs we know that the
mddev cannot disappear because it has an embedded kobj which
is refcounted by sysfs.
And we also take the mddev_lock.
However this is not enough.

The final mddev_put could have been called and the
mddev_delayed_delete is waiting for sysfs to let go so it can destroy
the kobj and mddev.
In this state there are a lot of changes that should not be attempted.

To to guard against this we:
 - initialise mddev->all_mddevs in on last put so the state can be
   easily detected.
 - in md_attr_show and md_attr_store, check ->all_mddevs under
   all_mddevs_lock and mddev_get the mddev if it still appears to
   be active.

This means that if we get to sysfs as the mddev is being deleted we
will get -EBUSY.

rdev_attr_store and rdev_attr_show are similar but already have
sufficient protection.  They check that rdev->mddev still points to
mddev after taking mddev_lock.  As this is cleared  before delayed
removal which can only be requested under the mddev_lock, this
ensure the rdev and mddev are still alive.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      af8a2434
    • NeilBrown's avatar
      md: refine interpretation of "hold_active == UNTIL_IOCTL". · 1d23f178
      NeilBrown authored 
      We like md devices to disappear when they really are not needed.
However it is not possible to tell from the current state whether it
is needed or not.  We can only tell from recent history of changes.

In particular immediately after we create an md device it looks very
similar to immediately after we have finished with it.

So we always preserve a newly created md device until something
significant happens.  This state is stored in 'hold_active'.

The normal case is to keep it until an ioctl happens, as that will
normally either activate it, or explicitly de-activate it.  If it
doesn't then it was probably created by mistake and it is now time to
get rid of it.

We can also modify an array via sysfs (instead of via ioctl) and we
currently treat any change via sysfs like an ioctl as a sign that if
it now isn't more active, it should be destroyed.
However this is not appropriate as changes made via sysfs are more
gradual so we should look for a more definitive change.

So this patch only clears 'hold_active' from UNTIL_IOCTL to clear when
the array_state is changed via sysfs.  Other changes via sysfs
are ignored.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      1d23f178
  7. 22 Nov, 2011 1 commit
    • NeilBrown's avatar
      md/lock: ensure updates to page_attrs are properly locked. · 7c8f4247
      NeilBrown authored 
      Page attributes are set using __set_bit rather than set_bit as
it normally called under a spinlock so the extra atomicity is not
needed.

However there are two places where we might set or clear page
attributes without holding the spinlock.
So add the spinlock in those cases.

This might be the cause of occasional reports that bits a aren't
getting clear properly - theory is that BITMAP_PAGE_PENDING gets lost
when BITMAP_PAGE_NEEDWRITE is set or cleared.  This is an
inconvenience, not a threat to data safety.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      7c8f4247
  9. 08 Nov, 2011 4 commits
  11. 07 Nov, 2011 21 commits
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