Hanjun Guo has reported that a CMA stress test causes broken accounting of
CMA and free pages:

> Before the test, I got:
> -bash-4.3# cat /proc/meminfo | grep Cma
> CmaTotal:         204800 kB
> CmaFree:          195044 kB
>
>
> After running the test:
> -bash-4.3# cat /proc/meminfo | grep Cma
> CmaTotal:         204800 kB
> CmaFree:         6602584 kB
>
> So the freed CMA memory is more than total..
>
> Also the the MemFree is more than mem total:
>
> -bash-4.3# cat /proc/meminfo
> MemTotal:       16342016 kB
> MemFree:        22367268 kB
> MemAvailable:   22370528 kB

Laura Abbott has confirmed the issue and suspected the freepage accounting
rewrite around 3.18/4.0 by Joonsoo Kim.  Joonsoo had a theory that this is
caused by unexpected merging between MIGRATE_ISOLATE and MIGRATE_CMA
pageblocks:

> CMA isolates MAX_ORDER aligned blocks, but, during the process,
> partialy isolated block exists. If MAX_ORDER is 11 and
> pageblock_order is 9, two pageblocks make up MAX_ORDER
> aligned block and I can think following scenario because pageblock
> (un)isolation would be done one by one.
>
> (each character means one pageblock. 'C', 'I' means MIGRATE_CMA,
> MIGRATE_ISOLATE, respectively.
>
> CC -> IC -> II (Isolation)
> II -> CI -> CC (Un-isolation)
>
> If some pages are freed at this intermediate state such as IC or CI,
> that page could be merged to the other page that is resident on
> different type of pageblock and it will cause wrong freepage count.

This was supposed to be prevented by CMA operating on MAX_ORDER blocks,
but since it doesn't hold the zone->lock between pageblocks, a race
window does exist.

It's also likely that unexpected merging can occur between
MIGRATE_ISOLATE and non-CMA pageblocks.  This should be prevented in
__free_one_page() since commit 3c605096 ("mm/page_alloc: restrict
max order of merging on isolated pageblock").  However, we only check
the migratetype of the pageblock where buddy merging has been initiated,
not the migratetype of the buddy pageblock (or group of pageblocks)
which can be MIGRATE_ISOLATE.

Joonsoo has suggested checking for buddy migratetype as part of
page_is_buddy(), but that would add extra checks in allocator hotpath
and bloat-o-meter has shown significant code bloat (the function is
inline).

This patch reduces the bloat at some expense of more complicated code.
The buddy-merging while-loop in __free_one_page() is initially bounded
to pageblock_border and without any migratetype checks.  The checks are
placed outside, bumping the max_order if merging is allowed, and
returning to the while-loop with a statement which can't be possibly
considered harmful.

This fixes the accounting bug and also removes the arguably weird state
in the original commit 3c605096 where buddies could be left
unmerged.

Fixes: 3c605096 ("mm/page_alloc: restrict max order of merging on isolated pageblock")
Link: https://lkml.org/lkml/2016/3/2/280Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
Reported-by: NHanjun Guo <guohanjun@huawei.com>
Tested-by: NHanjun Guo <guohanjun@huawei.com>
Acked-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Debugged-by: NLaura Abbott <labbott@redhat.com>
Debugged-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>	[3.18+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The r592 driver relies on behavior of the DMA mapping API that is
normally observed but not guaranteed by the API.  Instead it uses a
runtime check to fail transfers if the API ever behaves

When CONFIG_NEED_SG_DMA_LENGTH is not set, one of the checks turns into a
comparison of a variable with itself, which gcc-6.0 now warns about:

drivers/memstick/host/r592.c: In function 'r592_transfer_fifo_dma':
drivers/memstick/host/r592.c:302:31: error: self-comparison always evaluates to false [-Werror=tautological-compare]
    (sg_dma_len(&dev->req->sg) < dev->req->sg.length)) {
                               ^

The check itself is not a problem, so this patch just rephrases the
condition in a way that gcc does not consider an indication of a mistake.
We already know that dev->req->sg.length was initially R592_LFIFO_SIZE, so
we can compare it to that constant again.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Quentin Lambert <lambert.quentin@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now function ocfs2_replay_truncate_records() first modifies tl_used,
then calls ocfs2_extend_trans() to extend transactions for gd and alloc
inode used for freeing clusters.  jbd2_journal_restart() may be called
and it may happen that tl_used in truncate log is decreased but the
clusters are not freed, which means these clusters are lost.  So we
should avoid extending transactions in these two operations.
Signed-off-by: Njoyce.xue <xuejiufei@huawei.com>
Reviewed-by: NMark Fasheh <mfasheh@suse.de>
Acked-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ocfs2: extend transaction for ocfs2_remove_rightmost_path() and ocfs2_update_edge_lengths() before to avoid inconsistency between inode and et

I found that jbd2_journal_restart() is called in some places without
keeping things consistently before.  However, jbd2_journal_restart() may
commit the handle's transaction and restart another one.  If the first
transaction is committed successfully while another not, it may cause
filesystem inconsistency or read only.  This is an effort to fix this
kind of problems.

This patch (of 3):

The following functions will be called while truncating an extent:
ocfs2_remove_btree_range
  -> ocfs2_start_trans
  -> ocfs2_remove_extent
     -> ocfs2_truncate_rec
       -> ocfs2_extend_rotate_transaction
         -> jbd2_journal_restart if jbd2_journal_extend fail
       -> ocfs2_rotate_tree_left
         -> ocfs2_remove_rightmost_path
             -> ocfs2_extend_rotate_transaction
               -> ocfs2_unlink_subtree
                -> ocfs2_update_edge_lengths
                  -> ocfs2_extend_trans
                    -> jbd2_journal_restart if jbd2_journal_extend fail
  -> ocfs2_et_update_clusters
  -> ocfs2_commit_trans

jbd2_journal_restart() may be called and it may happened that the buffers
dirtied in ocfs2_truncate_rec() are committed while buffers dirtied in
ocfs2_et_update_clusters() are not, the total clusters on extent tree and
i_clusters in ocfs2_dinode is inconsistency.  So the clusters got from
ocfs2_dinode is incorrect, and it also cause read-only problem when call
ocfs2_commit_truncate() with the error message: "Inode %llu has empty
extent block at %llu".

We should extend enough credits for function ocfs2_remove_rightmost_path
and ocfs2_update_edge_lengths to avoid this inconsistency.
Signed-off-by: Njoyce.xue <xuejiufei@huawei.com>
Acked-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We have found a bug when two nodes doing umount one after another.

1) Node 1 migrate a lockres that has 3 locks in grant queue such as
   N2(PR)<->N3(NL)<->N4(PR) to N2.  After migration, lvb of the lock
   N3(NL) and N4(PR) are empty on node 2 because migration target do not
   copy lvb to these two lock.

2) Node 3 want to convert to PR, it can be granted in
   __dlmconvert_master(), and the order of these locks is unchanged.  The
   lvb of the lock N3(PR) on node 2 is copyed from lockres in function
   dlm_update_lvb() while the lvb of lock N4(PR) is still empty.

3) Node 2 want to leave domain, it will migrate this lockres to node 3.
   Then node 2 will trigger the BUG in dlm_prepare_lvb_for_migration()
   when adding the lock N4(PR) to mres with the following message because
   the lvb of mres is already copied from lock N3(PR), but the lvb of lock
   N4(PR) is empty.

"Mismatched lvb in lock cookie=%u:%llu, name=%.*s, node=%u"

[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Nxuejiufei <xuejiufei@huawei.com>
Acked-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In update_backups() there exists a problem of crossing the boundary as
follows:

we assume that lun will be resized to 1TB(cluster_size is 32kb), it will
include 0~33554431 cluster, in update_backups func, it will backup super
block in location of 1TB which is the 33554432th cluster, so the
phenomenon of crossing the boundary happens.
Signed-off-by: NYiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Xue jiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes a deadlock, as follows:

  Node 1                Node 2                  Node 3
1)volume a and b are    only mount vol a        only mount vol b
  mounted

2)                      start to mount b        start to mount a

3)                      check hb of Node 3      check hb of Node 2
                        in vol a, qs_holds++    in vol b, qs_holds++

4) -------------------- all nodes' network down --------------------

5)                      progress of mount b     the same situation as
                        failed, and then call   Node 2
                        ocfs2_dismount_volume.
                        but the process is hung,
                        since there is a work
                        in ocfs2_wq cannot beo
                        completed. This work is
                        about vol a, because
                        ocfs2_wq is global wq.
                        BTW, this work which is
                        scheduled in ocfs2_wq is
                        ocfs2_orphan_scan_work,
                        and the context in this work
                        needs to take inode lock
                        of orphan_dir, because
                        lockres owner are Node 1 and
                        all nodes' nework has been down
                        at the same time, so it can't
                        get the inode lock.

6)                      Why can't this node be fenced
                        when network disconnected?
                        Because the process of
                        mount is hung what caused qs_holds
                        is not equal 0.

Because all works in the ocfs2_wq are relative to the super block.

The solution is to change the ocfs2_wq from global to local.  In other
words, move it into struct ocfs2_super.
Signed-off-by: NYiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Xue jiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When master handles convert request, it queues ast first and then
returns status.  This may happen that the ast is sent before the request
status because the above two messages are sent by two threads.  And
right after the ast is sent, if master down, it may trigger BUG in
dlm_move_lockres_to_recovery_list in the requested node because ast
handler moves it to grant list without clear lock->convert_pending.  So
remove BUG_ON statement and check if the ast is processed in
dlmconvert_remote.
Signed-off-by: NJoseph Qi <joseph.qi@huawei.com>
Reported-by: NYiwen Jiang <jiangyiwen@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Tariq Saeed <tariq.x.saeed@oracle.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is a race window between dlmconvert_remote and
dlm_move_lockres_to_recovery_list, which will cause a lock with
OCFS2_LOCK_BUSY in grant list, thus system hangs.

dlmconvert_remote
{
        spin_lock(&res->spinlock);
        list_move_tail(&lock->list, &res->converting);
        lock->convert_pending = 1;
        spin_unlock(&res->spinlock);

        status = dlm_send_remote_convert_request();
        >>>>>> race window, master has queued ast and return DLM_NORMAL,
               and then down before sending ast.
               this node detects master down and calls
               dlm_move_lockres_to_recovery_list, which will revert the
               lock to grant list.
               Then OCFS2_LOCK_BUSY won't be cleared as new master won't
               send ast any more because it thinks already be authorized.

        spin_lock(&res->spinlock);
        lock->convert_pending = 0;
        if (status != DLM_NORMAL)
                dlm_revert_pending_convert(res, lock);
        spin_unlock(&res->spinlock);
}

In this case, check if res->state has DLM_LOCK_RES_RECOVERING bit set
(res is still in recovering) or res master changed (new master has
finished recovery), reset the status to DLM_RECOVERING, then it will
retry convert.
Signed-off-by: NJoseph Qi <joseph.qi@huawei.com>
Reported-by: NYiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Tariq Saeed <tariq.x.saeed@oracle.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The code should call ocfs2_free_alloc_context() to free meta_ac &
data_ac before calling ocfs2_run_deallocs().  Because
ocfs2_run_deallocs() will acquire the system inode's i_mutex hold by
meta_ac.  So try to release the lock before ocfs2_run_deallocs().

Fixes: af1310367f41 ("ocfs2: fix sparse file & data ordering issue in direct io.")
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Acked-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When doing append direct write in an already allocated cluster, and fast
path in ocfs2_dio_get_block() is triggered, function
ocfs2_dio_end_io_write() will be skipped as there is no context
allocated.

As a result, the disk file size will not be changed as it should be.
The solution is to skip fast path when we are about to change file size.

Fixes: af1310367f41 ("ocfs2: fix sparse file & data ordering issue in direct io.")
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Acked-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Take ip_alloc_sem to prevent concurrent access to extent tree, which may
cause the extent tree in an unstable state.
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the current implementation of unaligned aio+dio, lock order behave as
follow:

in user process context:
  -> call io_submit()
    -> get i_mutex
		<== window1
      -> get ip_unaligned_aio
        -> submit direct io to block device
    -> release i_mutex
  -> io_submit() return

in dio work queue context(the work queue is created in __blockdev_direct_IO):
  -> release ip_unaligned_aio
		<== window2
    -> get i_mutex
      -> clear unwritten flag & change i_size
    -> release i_mutex

There is a limitation to the thread number of dio work queue.  256 at
default.  If all 256 thread are in the above 'window2' stage, and there
is a user process in the 'window1' stage, the system will became
deadlock.  Since the user process hold i_mutex to wait ip_unaligned_aio
lock, while there is a direct bio hold ip_unaligned_aio mutex who is
waiting for a dio work queue thread to be schedule.  But all the dio
work queue thread is waiting for i_mutex lock in 'window2'.

This case only happened in a test which send a large number(more than
256) of aio at one io_submit() call.

My design is to remove ip_unaligned_aio lock.  Change it to a sync io
instead.  Just like ip_unaligned_aio lock, serialize the unaligned aio
dio.

[akpm@linux-foundation.org: remove OCFS2_IOCB_UNALIGNED_IO, per Junxiao Bi]
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Clean up ocfs2_file_write_iter & ocfs2_prepare_inode_for_write:
 * remove append dio check: it will be checked in ocfs2_direct_IO()
 * remove file hole check: file hole is supported for now
 * remove inline data check: it will be checked in ocfs2_direct_IO()
 * remove the full_coherence check when append dio: we will get the
   inode_lock in ocfs2_dio_get_block, there is no need to fall back to
   buffer io to ensure the coherence semantics.

Now the drop dio procedure is gone.  :)

[akpm@linux-foundation.org: remove unused label]
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are mainly three issues in the direct io code path after commit
24c40b32 ("ocfs2: implement ocfs2_direct_IO_write"):

  * Does not support sparse file.
  * Does not support data ordering.  eg: when write to a file hole, it
    will alloc extent first.  If system crashed before io finished, data
    will corrupt.
  * Potential risk when doing aio+dio.  The -EIOCBQUEUED return value is
    likely to be ignored by ocfs2_direct_IO_write().

To resolve above problems, re-design direct io code with following ideas:
  * Use buffer io to fill in holes.  And this will make better
    performance also.
  * Clear unwritten after direct write finished.  So we can make sure
    meta data changes after data write to disk.  (Unwritten extent is
    invisible to user, from user's view, meta data is not changed when
    allocate an unwritten extent.)
  * Clear ocfs2_direct_IO_write().  Do all ending work in end_io.

This patch has passed fs,dio,ltp-aiodio.part1,ltp-aiodio.part2,ltp-aiodio.part4
test cases of ltp.

For performance improvement, see following test result:
ocfs2 cluster size 1MB, ocfs2 volume is mounted on /mnt/.
The original way:
  + rm /mnt/test.img -f
  + dd if=/dev/zero of=/mnt/test.img bs=4K count=1048576 oflag=direct
  1048576+0 records in
  1048576+0 records out
  4294967296 bytes (4.3 GB) copied, 1707.83 s, 2.5 MB/s
  + rm /mnt/test.img -f
  + dd if=/dev/zero of=/mnt/test.img bs=256K count=16384 oflag=direct
  16384+0 records in
  16384+0 records out
  4294967296 bytes (4.3 GB) copied, 582.705 s, 7.4 MB/s

After this patch:
  + rm /mnt/test.img -f
  + dd if=/dev/zero of=/mnt/test.img bs=4K count=1048576 oflag=direct
  1048576+0 records in
  1048576+0 records out
  4294967296 bytes (4.3 GB) copied, 64.6412 s, 66.4 MB/s
  + rm /mnt/test.img -f
  + dd if=/dev/zero of=/mnt/test.img bs=256K count=16384 oflag=direct
  16384+0 records in
  16384+0 records out
  4294967296 bytes (4.3 GB) copied, 34.7611 s, 124 MB/s
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock.

There is still one issue in the direct write procedure.

phase 1: alloc extent with UNWRITTEN flag
phase 2: submit direct data to disk, add zero page to page cache
phase 3: clear UNWRITTEN flag when data has been written to disk

When there are 2 direct write A(0~3KB),B(4~7KB) writing to the same
cluster 0~7KB (cluster size 8KB).  Write request A arrive phase 2 first,
it will zero the region (4~7KB).  Before request A enter to phase 3,
request B arrive phase 2, it will zero region (0~3KB).  This is just like
request B steps request A.

To resolve this issue, we should let request B knows this cluster is already
under zero, to prevent it from steps the previous write request.

This patch will add function ocfs2_unwritten_check() to do this job.  It
will record all clusters that are under direct write(it will be recorded
in the 'ip_unwritten_list' member of inode info), and prevent the later
direct write writing to the same cluster to do the zero work again.
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock.

Direct io needs to get the physical address from write_begin, to map the
user page.  This patch is to change the arg 'phys' of
ocfs2_write_cluster to a pointer, so it can be retrieved to write_begin.
And we can retrieve it to the direct io procedure.
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock.

Append direct io do not change i_size in get block phase.  It only move
to orphan when starting write.  After data is written to disk, it will
delete itself from orphan and update i_size.  So skip i_size change
section in write_begin for direct io.

And when there is no extents alloc, no meta data changes needed for
direct io (since write_begin start trans for 2 reason: alloc extents &
change i_size.  Now none of them needed).  So we can skip start trans
procedure.
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock.

Direct io data will not appear in buffer.  The w_target_page member will
not be filled by direct io.  So avoid to use it when it's NULL.  Unlinke
buffer io and mmap, direct io will call write_begin with more than 1
page a time.  So the target_index is not sufficient to describe the
actual data.  change it to a range start at target_index, end in
end_index.
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock.

There is a problem in ocfs2's direct io implement: if system crashed
after extents allocated, and before data return, we will get a extent
with dirty data on disk.  This problem violate the journal=order
semantics, which means meta changes take effect after data written to
disk.  To resolve this issue, direct write can use the UNWRITTEN flag to
describe a extent during direct data writeback.  The direct write
procedure should act in the following order:

phase 1: alloc extent with UNWRITTEN flag
phase 2: submit direct data to disk, add zero page to page cache
phase 3: clear UNWRITTEN flag when data has been written to disk

This patch is to change the 'c_unwritten' member of
ocfs2_write_cluster_desc to 'c_clear_unwritten'.  Means whether to clear
the unwritten flag.  It do not care if a extent is allocated or not.
And use 'c_new' to specify a newly allocated extent.  So the direct io
procedure can use c_clear_unwritten to control the UNWRITTEN bit on
extent.
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patchset: fix ocfs2 direct io code patch to support sparse file and data
ordering semantics

The idea is to use buffer io(more precisely use the interface
ocfs2_write_begin_nolock & ocfs2_write_end_nolock) to do the zero work
beyond block size.  And clear UNWRITTEN flag until direct io data has
been written to disk, which can prevent data corruption when system
crashed during direct write.

And we will also archive a better performance: eg.  dd direct write new
file with block size 4KB: before this patchset:
  2.5 MB/s
after this patchset:
  66.4 MB/s

This patch (of 8):

To support direct io in ocfs2_write_begin_nolock &
ocfs2_write_end_nolock.

Remove unused args filp & flags.  Add new arg type.  The type is one of
buffer/direct/mmap.  Indicate 3 way to perform write.  buffer/mmap type
has implemented.  direct type will be implemented later.
Signed-off-by: NRyan Ding <ryan.ding@oracle.com>
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a regression issue and caused the following kernel panic when do
ocfs2 multiple test.

  BUG: unable to handle kernel paging request at 00000002000800c0
  IP: [<ffffffff81192978>] kmem_cache_alloc+0x78/0x160
  PGD 7bbe5067 PUD 0
  Oops: 0000 [#1] SMP
  Modules linked in: ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi xen_kbdfront xen_netfront xen_fbfront xen_blkfront
  CPU: 2 PID: 4044 Comm: mpirun Not tainted 4.5.0-rc5-next-20160225 #1
  Hardware name: Xen HVM domU, BIOS 4.3.1OVM 05/14/2014
  task: ffff88007a521a80 ti: ffff88007aed0000 task.ti: ffff88007aed0000
  RIP: 0010:[<ffffffff81192978>]  [<ffffffff81192978>] kmem_cache_alloc+0x78/0x160
  RSP: 0018:ffff88007aed3a48  EFLAGS: 00010282
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000001991
  RDX: 0000000000001990 RSI: 00000000024000c0 RDI: 000000000001b330
  RBP: ffff88007aed3a98 R08: ffff88007d29b330 R09: 00000002000800c0
  R10: 0000000c51376d87 R11: ffff8800792cac38 R12: ffff88007cc30f00
  R13: 00000000024000c0 R14: ffffffff811b053f R15: ffff88007aed3ce7
  FS:  0000000000000000(0000) GS:ffff88007d280000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000002000800c0 CR3: 000000007aeb2000 CR4: 00000000000406e0
  Call Trace:
    __d_alloc+0x2f/0x1a0
    d_alloc+0x17/0x80
    lookup_dcache+0x8a/0xc0
    path_openat+0x3c3/0x1210
    do_filp_open+0x80/0xe0
    do_sys_open+0x110/0x200
    SyS_open+0x19/0x20
    do_syscall_64+0x72/0x230
    entry_SYSCALL64_slow_path+0x25/0x25
  Code: 05 e6 77 e7 7e 4d 8b 08 49 8b 40 10 4d 85 c9 0f 84 dd 00 00 00 48 85 c0 0f 84 d4 00 00 00 49 63 44 24 20 49 8b 3c 24 48 8d 4a 01 <49> 8b 1c 01 4c 89 c8 65 48 0f c7 0f 0f 94 c0 3c 01 75 b6 49 63
  RIP   kmem_cache_alloc+0x78/0x160
  CR2: 00000002000800c0
  ---[ end trace 823969e602e4aaac ]---

Fixes: a4a1dfa4("ocfs2/cluster: fix memory leak in o2hb_region_release")
Signed-off-by: NJunxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

INPUT_COMPAT_TEST became much simpler after commit f4056b52
("input: redefine INPUT_COMPAT_TEST as in_compat_syscall()") so we can
cleanly eliminate it altogether.
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task" tried
to protect oom_reaper_list using MMF_OOM_KILLED flag.  But we can do it
by simply checking tsk->oom_reaper_list != NULL.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After "oom: clear TIF_MEMDIE after oom_reaper managed to unmap the
address space" oom_reaper will call exit_oom_victim on the target task
after it is done.  This might however race with the PM freezer:

CPU0				CPU1				CPU2
freeze_processes
  try_to_freeze_tasks
  				# Allocation request
				out_of_memory
  oom_killer_disable
				  wake_oom_reaper(P1)
				  				__oom_reap_task
								  exit_oom_victim(P1)
    wait_event(oom_victims==0)
[...]
    				do_exit(P1)
				  perform IO/interfere with the freezer

which breaks the oom_killer_disable semantic.  We no longer have a
guarantee that the oom victim won't interfere with the freezer because
it might be anywhere on the way to do_exit while the freezer thinks the
task has already terminated.  It might trigger IO or touch devices which
are frozen already.

In order to close this race, make the oom_reaper thread freezable.  This
will work because
	a) already running oom_reaper will block freezer to enter the
	   quiescent state
	b) wake_oom_reaper will not wake up the reaper after it has been
	   frozen
	c) the only way to call exit_oom_victim after try_to_freeze_tasks
	   is from the oom victim's context when we know the further
	   interference shouldn't be possible
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Entries are only added/removed from oom_reaper_list at head so we can
use a single linked list and hence save a word in task_struct.
Signed-off-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Tetsuo has reported that oom_kill_allocating_task=1 will cause
oom_reaper_list corruption because oom_kill_process doesn't follow
standard OOM exclusion (aka ignores TIF_MEMDIE) and allows to enqueue
the same task multiple times - e.g.  by sacrificing the same child
multiple times.

This patch fixes the issue by introducing a new MMF_OOM_KILLED mm flag
which is set in oom_kill_process atomically and oom reaper is disabled
if the flag was already set.
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Reported-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

wake_oom_reaper has allowed only 1 oom victim to be queued.  The main
reason for that was the simplicity as other solutions would require some
way of queuing.  The current approach is racy and that was deemed
sufficient as the oom_reaper is considered a best effort approach to
help with oom handling when the OOM victim cannot terminate in a
reasonable time.  The race could lead to missing an oom victim which can
get stuck

out_of_memory
  wake_oom_reaper
    cmpxchg // OK
    			oom_reaper
			  oom_reap_task
			    __oom_reap_task
oom_victim terminates
			      atomic_inc_not_zero // fail
out_of_memory
  wake_oom_reaper
    cmpxchg // fails
			  task_to_reap = NULL

This race requires 2 OOM invocations in a short time period which is not
very likely but certainly not impossible.  E.g.  the original victim
might have not released a lot of memory for some reason.

The situation would improve considerably if wake_oom_reaper used a more
robust queuing.  This is what this patch implements.  This means adding
oom_reaper_list list_head into task_struct (eat a hole before embeded
thread_struct for that purpose) and a oom_reaper_lock spinlock for
queuing synchronization.  wake_oom_reaper will then add the task on the
queue and oom_reaper will dequeue it.
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Andrea Argangeli <andrea@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Inform about the successful/failed oom_reaper attempts and dump all the
held locks to tell us more who is blocking the progress.

[akpm@linux-foundation.org: fix CONFIG_MMU=n build]
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Cc: Andrea Argangeli <andrea@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When oom_reaper manages to unmap all the eligible vmas there shouldn't
be much of the freable memory held by the oom victim left anymore so it
makes sense to clear the TIF_MEMDIE flag for the victim and allow the
OOM killer to select another task.

The lack of TIF_MEMDIE also means that the victim cannot access memory
reserves anymore but that shouldn't be a problem because it would get
the access again if it needs to allocate and hits the OOM killer again
due to the fatal_signal_pending resp.  PF_EXITING check.  We can safely
hide the task from the OOM killer because it is clearly not a good
candidate anymore as everyhing reclaimable has been torn down already.

This patch will allow to cap the time an OOM victim can keep TIF_MEMDIE
and thus hold off further global OOM killer actions granted the oom
reaper is able to take mmap_sem for the associated mm struct.  This is
not guaranteed now but further steps should make sure that mmap_sem for
write should be blocked killable which will help to reduce such a lock
contention.  This is not done by this patch.

Note that exit_oom_victim might be called on a remote task from
__oom_reap_task now so we have to check and clear the flag atomically
otherwise we might race and underflow oom_victims or wake up waiters too
early.
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Suggested-by: NJohannes Weiner <hannes@cmpxchg.org>
Suggested-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Andrea Argangeli <andrea@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch (of 5):

This is based on the idea from Mel Gorman discussed during LSFMM 2015
and independently brought up by Oleg Nesterov.

The OOM killer currently allows to kill only a single task in a good
hope that the task will terminate in a reasonable time and frees up its
memory.  Such a task (oom victim) will get an access to memory reserves
via mark_oom_victim to allow a forward progress should there be a need
for additional memory during exit path.

It has been shown (e.g.  by Tetsuo Handa) that it is not that hard to
construct workloads which break the core assumption mentioned above and
the OOM victim might take unbounded amount of time to exit because it
might be blocked in the uninterruptible state waiting for an event (e.g.
lock) which is blocked by another task looping in the page allocator.

This patch reduces the probability of such a lockup by introducing a
specialized kernel thread (oom_reaper) which tries to reclaim additional
memory by preemptively reaping the anonymous or swapped out memory owned
by the oom victim under an assumption that such a memory won't be needed
when its owner is killed and kicked from the userspace anyway.  There is
one notable exception to this, though, if the OOM victim was in the
process of coredumping the result would be incomplete.  This is
considered a reasonable constrain because the overall system health is
more important than debugability of a particular application.

A kernel thread has been chosen because we need a reliable way of
invocation so workqueue context is not appropriate because all the
workers might be busy (e.g.  allocating memory).  Kswapd which sounds
like another good fit is not appropriate as well because it might get
blocked on locks during reclaim as well.

oom_reaper has to take mmap_sem on the target task for reading so the
solution is not 100% because the semaphore might be held or blocked for
write but the probability is reduced considerably wrt.  basically any
lock blocking forward progress as described above.  In order to prevent
from blocking on the lock without any forward progress we are using only
a trylock and retry 10 times with a short sleep in between.  Users of
mmap_sem which need it for write should be carefully reviewed to use
_killable waiting as much as possible and reduce allocations requests
done with the lock held to absolute minimum to reduce the risk even
further.

The API between oom killer and oom reaper is quite trivial.
wake_oom_reaper updates mm_to_reap with cmpxchg to guarantee only
NULL->mm transition and oom_reaper clear this atomically once it is done
with the work.  This means that only a single mm_struct can be reaped at
the time.  As the operation is potentially disruptive we are trying to
limit it to the ncessary minimum and the reaper blocks any updates while
it operates on an mm.  mm_struct is pinned by mm_count to allow parallel
exit_mmap and a race is detected by atomic_inc_not_zero(mm_users).
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Suggested-by: NOleg Nesterov <oleg@redhat.com>
Suggested-by: NMel Gorman <mgorman@suse.de>
Acked-by: NMel Gorman <mgorman@suse.de>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Argangeli <andrea@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This will be needed in the patch "mm, oom: introduce oom reaper".
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit e7223f18.

It causes problems when a ppdev tries to register before the parport
driver has been registered with the device model. That will trigger the

        BUG_ON(!drv->bus->p);

at drivers/base/driver.c:153. The call chain is

  kernel_init ->
    kernel_init_freeable ->
      do_one_initcall ->
        ppdev_init ->
          __parport_register_driver ->
            driver_register *BOOM*
Reported-by: Nkernel test robot <fengguang.wu@intel.com>
Reported-by: NRoss Zwisler <zwisler@gmail.com>
Reported-by: NPetr Mladek <pmladek@suse.com>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull firewire leftover from Stefan Richter:
 "Occurrences of timeval were supposed to be eliminated last round, now
  remove a last forgotten one"

* tag 'firewire-update2' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: nosy: Replace timeval with timespec64

Pull drm fixes from Dave Airlie:
 "Just a couple of dma-buf related fixes and some amdgpu fixes, along
  with a regression fix for radeon off but default feature, but makes my
  30" monitor happy again"

* 'drm-next' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/mst: cleanup code indentation
  drm/radeon/mst: fix regression in lane/link handling.
  drm/amdgpu: add invalidate_page callback for userptrs
  drm/amdgpu: Revert "remove the userptr rmn->lock"
  drm/amdgpu: clean up path handling for powerplay
  drm/amd/powerplay: fix memory leak of tdp_table
  dma-buf/fence: fix fence_is_later v2
  dma-buf: Update docs for SYNC ioctl
  drm: remove excess description
  dma-buf, drm, ion: Propagate error code from dma_buf_start_cpu_access()
  drm/atmel-hlcdc: use helper to get crtc state
  drm/atomic: use helper to get crtc state

Pull asm-generic updates from Arnd Bergmann:
 "There are only three patches this time, most other changes to files in
  include/asm-generic tend to go through the tree of whoever depends on
  the change.

  Two patches are cleanups for stuff that is no longer needed, the main
  change is to adapt the generic version of BUG_ON() for CONFIG_BUG=n to
  make it behave consistently with BUG().

  This avoids undefined behavior along with a number of warnings about
  that undefined behavior in randconfig builds when we keep going on
  after hitting a BUG_ON()"

* tag 'asm-generic-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: remove old nonatomic-io wrapper files
  asm-generic: default BUG_ON(x) to if(x)BUG()
  asm-generic: page.h: Remove useless get_user_page and free_user_page

some amd fixes
* 'drm-next-4.6' of git://people.freedesktop.org/~agd5f/linux:
  drm/radeon/mst: cleanup code indentation
  drm/radeon/mst: fix regression in lane/link handling.
  drm/amdgpu: add invalidate_page callback for userptrs
  drm/amdgpu: Revert "remove the userptr rmn->lock"
  drm/amdgpu: clean up path handling for powerplay
  drm/amd/powerplay: fix memory leak of tdp_table

Pull more power management and ACPI updates from Rafael Wysocki:
 "The second batch of power management and ACPI updates for v4.6.

  Included are fixups on top of the previous PM/ACPI pull request and
  other material that didn't make into it but still should go into 4.6.

  Among other things, there's a fix for an intel_pstate driver issue
  uncovered by recent cpufreq changes, a workaround for a boot hang on
  Skylake-H related to the handling of deep C-states by the platform and
  a PCI/ACPI fix for the handling of IO port resources on non-x86
  architectures plus some new device IDs and similar.

  Specifics:

   - Fix for an intel_pstate driver issue related to the handling of MSR
     updates uncovered by the recent cpufreq rework (Rafael Wysocki).

   - cpufreq core cleanups related to starting governors and frequency
     synchronization during resume from system suspend and a locking fix
     for cpufreq_quick_get() (Rafael Wysocki, Richard Cochran).

   - acpi-cpufreq and powernv cpufreq driver updates (Jisheng Zhang,
     Michael Neuling, Richard Cochran, Shilpasri Bhat).

   - intel_idle driver update preventing some Skylake-H systems from
     hanging during initialization by disabling deep C-states mishandled
     by the platform in the problematic configurations (Len Brown).

   - Intel Xeon Phi Processor x200 support for intel_idle
     (Dasaratharaman Chandramouli).

   - cpuidle menu governor updates to make it always honor PM QoS
     latency constraints (and prevent C1 from being used as the fallback
     C-state on x86 when they are set below its exit latency) and to
     restore the previous behavior to fall back to C1 if the next timer
     event is set far enough in the future that was changed in 4.4 which
     led to an energy consumption regression (Rik van Riel, Rafael
     Wysocki).

   - New device ID for a future AMD UART controller in the ACPI driver
     for AMD SoCs (Wang Hongcheng).

   - Rockchip rk3399 support for the rockchip-io-domain adaptive voltage
     scaling (AVS) driver (David Wu).

   - ACPI PCI resources management fix for the handling of IO space
     resources on architectures where the IO space is memory mapped
     (IA64 and ARM64) broken by the introduction of common ACPI
     resources parsing for PCI host bridges in 4.4 (Lorenzo Pieralisi).

   - Fix for the ACPI backend of the generic device properties API to
     make it parse non-device (data node only) children of an ACPI
     device correctly (Irina Tirdea).

   - Fixes for the handling of global suspend flags (introduced in 4.4)
     during hibernation and resume from it (Lukas Wunner).

   - Support for obtaining configuration information from Device Trees
     in the PM clocks framework (Jon Hunter).

   - ACPI _DSM helper code and devfreq framework cleanups (Colin Ian
     King, Geert Uytterhoeven)"

* tag 'pm+acpi-4.6-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (23 commits)
  PM / AVS: rockchip-io: add io selectors and supplies for rk3399
  intel_idle: Support for Intel Xeon Phi Processor x200 Product Family
  intel_idle: prevent SKL-H boot failure when C8+C9+C10 enabled
  ACPI / PM: Runtime resume devices when waking from hibernate
  PM / sleep: Clear pm_suspend_global_flags upon hibernate
  cpufreq: governor: Always schedule work on the CPU running update
  cpufreq: Always update current frequency before startig governor
  cpufreq: Introduce cpufreq_update_current_freq()
  cpufreq: Introduce cpufreq_start_governor()
  cpufreq: powernv: Add sysfs attributes to show throttle stats
  cpufreq: acpi-cpufreq: make Intel/AMD MSR access, io port access static
  PCI: ACPI: IA64: fix IO port generic range check
  ACPI / util: cast data to u64 before shifting to fix sign extension
  cpufreq: powernv: Define per_cpu chip pointer to optimize hot-path
  cpuidle: menu: Fall back to polling if next timer event is near
  cpufreq: acpi-cpufreq: Clean up hot plug notifier callback
  intel_pstate: Do not call wrmsrl_on_cpu() with disabled interrupts
  cpufreq: Make cpufreq_quick_get() safe to call
  ACPI / property: fix data node parsing in acpi_get_next_subnode()
  ACPI / APD: Add device HID for future AMD UART controller
  ...

Pull more RTC updates from Alexandre Belloni:
 "A second pull request for v4.6 with a few fixesi before -rc1.  The new
  features for abx80x actually make the RTC behave correctly.

  Drivers:
   - abx80x: handle both XT and RC oscillators, XT failure bit and
     autocalibration
   - m41t80: avoid out of range year values
   - rv8803: workaround an i2c HW issue"

* tag 'rtc-4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
  rtc: abx80x: handle the oscillator failure bit
  rtc: abx80x: handle autocalibration
  rtc: rv8803: workaround i2c HW issue
  rtc: mcp795: add devicetree support
  rtc: asm9260: remove incorrect __init/__exit annotations
  rtc: m41t80: avoid out of range year values
  rtc: s3c: Don't print an error on probe deferral
  rtc: rv3029: stop mentioning rv3029c2

Merge tag 'hwmon-for-linus-v4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull more hwmon updates from Guenter Roeck:
 "Update hwmon mailing list and web page"

* tag 'hwmon-for-linus-v4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  MAINTAINERS: Update mailing list and web page for hwmon subsystem