<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux, branch v4.7.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>IB/mlx5: Fix MODIFY_QP command input structure</title>
<updated>2016-08-20T16:11:02+00:00</updated>
<author>
<name>Artemy Kovalyov</name>
<email>artemyko@mellanox.com</email>
</author>
<published>2016-06-17T12:33:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8be3949fcc62090a2ad6d77ca73db238c1866f04'/>
<id>8be3949fcc62090a2ad6d77ca73db238c1866f04</id>
<content type='text'>
commit e3353c268b06236d6c40fa1714c114f21f44451c upstream.

Make MODIFY_QP command input structure compliant to specification

Fixes: e126ba97dba9 ('mlx5: Add driver for Mellanox Connect-IB adapters')
Signed-off-by: Artemy Kovalyov &lt;artemyko@mellanox.com&gt;
Signed-off-by: Leon Romanovsky &lt;leon@kernel.org&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit e3353c268b06236d6c40fa1714c114f21f44451c upstream.

Make MODIFY_QP command input structure compliant to specification

Fixes: e126ba97dba9 ('mlx5: Add driver for Mellanox Connect-IB adapters')
Signed-off-by: Artemy Kovalyov &lt;artemyko@mellanox.com&gt;
Signed-off-by: Leon Romanovsky &lt;leon@kernel.org&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>block: fix bdi vs gendisk lifetime mismatch</title>
<updated>2016-08-20T16:11:01+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2016-07-31T18:15:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b410df3a2f05771c5ee55248c2d4604453a95c14'/>
<id>b410df3a2f05771c5ee55248c2d4604453a95c14</id>
<content type='text'>
commit df08c32ce3be5be138c1dbfcba203314a3a7cd6f upstream.

The name for a bdi of a gendisk is derived from the gendisk's devt.
However, since the gendisk is destroyed before the bdi it leaves a
window where a new gendisk could dynamically reuse the same devt while a
bdi with the same name is still live.  Arrange for the bdi to hold a
reference against its "owner" disk device while it is registered.
Otherwise we can hit sysfs duplicate name collisions like the following:

 WARNING: CPU: 10 PID: 2078 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x80
 sysfs: cannot create duplicate filename '/devices/virtual/bdi/259:1'

 Hardware name: HP ProLiant DL580 Gen8, BIOS P79 05/06/2015
  0000000000000286 0000000002c04ad5 ffff88006f24f970 ffffffff8134caec
  ffff88006f24f9c0 0000000000000000 ffff88006f24f9b0 ffffffff8108c351
  0000001f0000000c ffff88105d236000 ffff88105d1031e0 ffff8800357427f8
 Call Trace:
  [&lt;ffffffff8134caec&gt;] dump_stack+0x63/0x87
  [&lt;ffffffff8108c351&gt;] __warn+0xd1/0xf0
  [&lt;ffffffff8108c3cf&gt;] warn_slowpath_fmt+0x5f/0x80
  [&lt;ffffffff812a0d34&gt;] sysfs_warn_dup+0x64/0x80
  [&lt;ffffffff812a0e1e&gt;] sysfs_create_dir_ns+0x7e/0x90
  [&lt;ffffffff8134faaa&gt;] kobject_add_internal+0xaa/0x320
  [&lt;ffffffff81358d4e&gt;] ? vsnprintf+0x34e/0x4d0
  [&lt;ffffffff8134ff55&gt;] kobject_add+0x75/0xd0
  [&lt;ffffffff816e66b2&gt;] ? mutex_lock+0x12/0x2f
  [&lt;ffffffff8148b0a5&gt;] device_add+0x125/0x610
  [&lt;ffffffff8148b788&gt;] device_create_groups_vargs+0xd8/0x100
  [&lt;ffffffff8148b7cc&gt;] device_create_vargs+0x1c/0x20
  [&lt;ffffffff811b775c&gt;] bdi_register+0x8c/0x180
  [&lt;ffffffff811b7877&gt;] bdi_register_dev+0x27/0x30
  [&lt;ffffffff813317f5&gt;] add_disk+0x175/0x4a0

Reported-by: Yi Zhang &lt;yizhan@redhat.com&gt;
Tested-by: Yi Zhang &lt;yizhan@redhat.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

Fixed up missing 0 return in bdi_register_owner().

Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit df08c32ce3be5be138c1dbfcba203314a3a7cd6f upstream.

The name for a bdi of a gendisk is derived from the gendisk's devt.
However, since the gendisk is destroyed before the bdi it leaves a
window where a new gendisk could dynamically reuse the same devt while a
bdi with the same name is still live.  Arrange for the bdi to hold a
reference against its "owner" disk device while it is registered.
Otherwise we can hit sysfs duplicate name collisions like the following:

 WARNING: CPU: 10 PID: 2078 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x80
 sysfs: cannot create duplicate filename '/devices/virtual/bdi/259:1'

 Hardware name: HP ProLiant DL580 Gen8, BIOS P79 05/06/2015
  0000000000000286 0000000002c04ad5 ffff88006f24f970 ffffffff8134caec
  ffff88006f24f9c0 0000000000000000 ffff88006f24f9b0 ffffffff8108c351
  0000001f0000000c ffff88105d236000 ffff88105d1031e0 ffff8800357427f8
 Call Trace:
  [&lt;ffffffff8134caec&gt;] dump_stack+0x63/0x87
  [&lt;ffffffff8108c351&gt;] __warn+0xd1/0xf0
  [&lt;ffffffff8108c3cf&gt;] warn_slowpath_fmt+0x5f/0x80
  [&lt;ffffffff812a0d34&gt;] sysfs_warn_dup+0x64/0x80
  [&lt;ffffffff812a0e1e&gt;] sysfs_create_dir_ns+0x7e/0x90
  [&lt;ffffffff8134faaa&gt;] kobject_add_internal+0xaa/0x320
  [&lt;ffffffff81358d4e&gt;] ? vsnprintf+0x34e/0x4d0
  [&lt;ffffffff8134ff55&gt;] kobject_add+0x75/0xd0
  [&lt;ffffffff816e66b2&gt;] ? mutex_lock+0x12/0x2f
  [&lt;ffffffff8148b0a5&gt;] device_add+0x125/0x610
  [&lt;ffffffff8148b788&gt;] device_create_groups_vargs+0xd8/0x100
  [&lt;ffffffff8148b7cc&gt;] device_create_vargs+0x1c/0x20
  [&lt;ffffffff811b775c&gt;] bdi_register+0x8c/0x180
  [&lt;ffffffff811b7877&gt;] bdi_register_dev+0x27/0x30
  [&lt;ffffffff813317f5&gt;] add_disk+0x175/0x4a0

Reported-by: Yi Zhang &lt;yizhan@redhat.com&gt;
Tested-by: Yi Zhang &lt;yizhan@redhat.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

Fixed up missing 0 return in bdi_register_owner().

Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>block: add missing group association in bio-cloning functions</title>
<updated>2016-08-20T16:11:01+00:00</updated>
<author>
<name>Paolo Valente</name>
<email>paolo.valente@linaro.org</email>
</author>
<published>2016-07-27T05:22:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f495a60eb6351bf2f29fdbc1854375df9fe4022b'/>
<id>f495a60eb6351bf2f29fdbc1854375df9fe4022b</id>
<content type='text'>
commit 20bd723ec6a3261df5e02250cd3a1fbb09a343f2 upstream.

When a bio is cloned, the newly created bio must be associated with
the same blkcg as the original bio (if BLK_CGROUP is enabled). If
this operation is not performed, then the new bio is not associated
with any group, and the group of the current task is returned when
the group of the bio is requested.

Depending on the cloning frequency, this may cause a large
percentage of the bios belonging to a given group to be treated
as if belonging to other groups (in most cases as if belonging to
the root group). The expected group isolation may thereby be broken.

This commit adds the missing association in bio-cloning functions.

Fixes: da2f0f74cf7d ("Btrfs: add support for blkio controllers")

Signed-off-by: Paolo Valente &lt;paolo.valente@linaro.org&gt;
Reviewed-by: Nikolay Borisov &lt;kernel@kyup.com&gt;
Reviewed-by: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 20bd723ec6a3261df5e02250cd3a1fbb09a343f2 upstream.

When a bio is cloned, the newly created bio must be associated with
the same blkcg as the original bio (if BLK_CGROUP is enabled). If
this operation is not performed, then the new bio is not associated
with any group, and the group of the current task is returned when
the group of the bio is requested.

Depending on the cloning frequency, this may cause a large
percentage of the bios belonging to a given group to be treated
as if belonging to other groups (in most cases as if belonging to
the root group). The expected group isolation may thereby be broken.

This commit adds the missing association in bio-cloning functions.

Fixes: da2f0f74cf7d ("Btrfs: add support for blkio controllers")

Signed-off-by: Paolo Valente &lt;paolo.valente@linaro.org&gt;
Reviewed-by: Nikolay Borisov &lt;kernel@kyup.com&gt;
Reviewed-by: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2016-07-23T06:44:31+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-07-23T06:44:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=107df03203bb66de56e2caec3bde6d22b55480c5'/>
<id>107df03203bb66de56e2caec3bde6d22b55480c5</id>
<content type='text'>
Pull networking fixes from David Miller:

 1) Fix memory leak in nftables, from Liping Zhang.

 2) Need to check result of vlan_insert_tag() in batman-adv otherwise we
    risk NULL skb derefs, from Sven Eckelmann.

 3) Check for dev_alloc_skb() failures in cfg80211, from Gregory
    Greenman.

 4) Handle properly when we have ppp_unregister_channel() happening in
    parallel with ppp_connect_channel(), from WANG Cong.

 5) Fix DCCP deadlock, from Eric Dumazet.

 6) Bail out properly in UDP if sk_filter() truncates the packet to be
    smaller than even the space that the protocol headers need.  From
    Michal Kubecek.

 7) Similarly for rose, dccp, and sctp, from Willem de Bruijn.

 8) Make TCP challenge ACKs less predictable, from Eric Dumazet.

 9) Fix infinite loop in bgmac_dma_tx_add() from Florian Fainelli.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
  packet: propagate sock_cmsg_send() error
  net/mlx5e: Fix del vxlan port command buffer memset
  packet: fix second argument of sock_tx_timestamp()
  net: switchdev: change ageing_time type to clock_t
  Update maintainer for EHEA driver.
  net/mlx4_en: Add resilience in low memory systems
  net/mlx4_en: Move filters cleanup to a proper location
  sctp: load transport header after sk_filter
  net/sched/sch_htb: clamp xstats tokens to fit into 32-bit int
  net: cavium: liquidio: Avoid dma_unmap_single on uninitialized ndata
  net: nb8800: Fix SKB leak in nb8800_receive()
  et131x: Fix logical vs bitwise check in et131x_tx_timeout()
  vlan: use a valid default mtu value for vlan over macsec
  net: bgmac: Fix infinite loop in bgmac_dma_tx_add()
  mlxsw: spectrum: Prevent invalid ingress buffer mapping
  mlxsw: spectrum: Prevent overwrite of DCB capability fields
  mlxsw: spectrum: Don't emit errors when PFC is disabled
  mlxsw: spectrum: Indicate support for autonegotiation
  mlxsw: spectrum: Force link training according to admin state
  r8152: add MODULE_VERSION
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from David Miller:

 1) Fix memory leak in nftables, from Liping Zhang.

 2) Need to check result of vlan_insert_tag() in batman-adv otherwise we
    risk NULL skb derefs, from Sven Eckelmann.

 3) Check for dev_alloc_skb() failures in cfg80211, from Gregory
    Greenman.

 4) Handle properly when we have ppp_unregister_channel() happening in
    parallel with ppp_connect_channel(), from WANG Cong.

 5) Fix DCCP deadlock, from Eric Dumazet.

 6) Bail out properly in UDP if sk_filter() truncates the packet to be
    smaller than even the space that the protocol headers need.  From
    Michal Kubecek.

 7) Similarly for rose, dccp, and sctp, from Willem de Bruijn.

 8) Make TCP challenge ACKs less predictable, from Eric Dumazet.

 9) Fix infinite loop in bgmac_dma_tx_add() from Florian Fainelli.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
  packet: propagate sock_cmsg_send() error
  net/mlx5e: Fix del vxlan port command buffer memset
  packet: fix second argument of sock_tx_timestamp()
  net: switchdev: change ageing_time type to clock_t
  Update maintainer for EHEA driver.
  net/mlx4_en: Add resilience in low memory systems
  net/mlx4_en: Move filters cleanup to a proper location
  sctp: load transport header after sk_filter
  net/sched/sch_htb: clamp xstats tokens to fit into 32-bit int
  net: cavium: liquidio: Avoid dma_unmap_single on uninitialized ndata
  net: nb8800: Fix SKB leak in nb8800_receive()
  et131x: Fix logical vs bitwise check in et131x_tx_timeout()
  vlan: use a valid default mtu value for vlan over macsec
  net: bgmac: Fix infinite loop in bgmac_dma_tx_add()
  mlxsw: spectrum: Prevent invalid ingress buffer mapping
  mlxsw: spectrum: Prevent overwrite of DCB capability fields
  mlxsw: spectrum: Don't emit errors when PFC is disabled
  mlxsw: spectrum: Indicate support for autonegotiation
  mlxsw: spectrum: Force link training according to admin state
  r8152: add MODULE_VERSION
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>radix-tree: fix radix_tree_iter_retry() for tagged iterators.</title>
<updated>2016-07-23T01:25:54+00:00</updated>
<author>
<name>Andrey Ryabinin</name>
<email>aryabinin@virtuozzo.com</email>
</author>
<published>2016-07-20T22:45:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3cb9185c67304b2a7ea9be73e7d13df6fb2793a1'/>
<id>3cb9185c67304b2a7ea9be73e7d13df6fb2793a1</id>
<content type='text'>
radix_tree_iter_retry() resets slot to NULL, but it doesn't reset tags.
Then NULL slot and non-zero iter.tags passed to radix_tree_next_slot()
leading to crash:

  RIP: radix_tree_next_slot include/linux/radix-tree.h:473
    find_get_pages_tag+0x334/0x930 mm/filemap.c:1452
  ....
  Call Trace:
    pagevec_lookup_tag+0x3a/0x80 mm/swap.c:960
    mpage_prepare_extent_to_map+0x321/0xa90 fs/ext4/inode.c:2516
    ext4_writepages+0x10be/0x2b20 fs/ext4/inode.c:2736
    do_writepages+0x97/0x100 mm/page-writeback.c:2364
    __filemap_fdatawrite_range+0x248/0x2e0 mm/filemap.c:300
    filemap_write_and_wait_range+0x121/0x1b0 mm/filemap.c:490
    ext4_sync_file+0x34d/0xdb0 fs/ext4/fsync.c:115
    vfs_fsync_range+0x10a/0x250 fs/sync.c:195
    vfs_fsync fs/sync.c:209
    do_fsync+0x42/0x70 fs/sync.c:219
    SYSC_fdatasync fs/sync.c:232
    SyS_fdatasync+0x19/0x20 fs/sync.c:230
    entry_SYSCALL_64_fastpath+0x23/0xc1 arch/x86/entry/entry_64.S:207

We must reset iterator's tags to bail out from radix_tree_next_slot()
and go to the slow-path in radix_tree_next_chunk().

Fixes: 46437f9a554f ("radix-tree: fix race in gang lookup")
Link: http://lkml.kernel.org/r/1468495196-10604-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Reported-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Acked-by: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Cc: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Cc: Hugh Dickins &lt;hughd@google.com&gt;
Cc: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
radix_tree_iter_retry() resets slot to NULL, but it doesn't reset tags.
Then NULL slot and non-zero iter.tags passed to radix_tree_next_slot()
leading to crash:

  RIP: radix_tree_next_slot include/linux/radix-tree.h:473
    find_get_pages_tag+0x334/0x930 mm/filemap.c:1452
  ....
  Call Trace:
    pagevec_lookup_tag+0x3a/0x80 mm/swap.c:960
    mpage_prepare_extent_to_map+0x321/0xa90 fs/ext4/inode.c:2516
    ext4_writepages+0x10be/0x2b20 fs/ext4/inode.c:2736
    do_writepages+0x97/0x100 mm/page-writeback.c:2364
    __filemap_fdatawrite_range+0x248/0x2e0 mm/filemap.c:300
    filemap_write_and_wait_range+0x121/0x1b0 mm/filemap.c:490
    ext4_sync_file+0x34d/0xdb0 fs/ext4/fsync.c:115
    vfs_fsync_range+0x10a/0x250 fs/sync.c:195
    vfs_fsync fs/sync.c:209
    do_fsync+0x42/0x70 fs/sync.c:219
    SYSC_fdatasync fs/sync.c:232
    SyS_fdatasync+0x19/0x20 fs/sync.c:230
    entry_SYSCALL_64_fastpath+0x23/0xc1 arch/x86/entry/entry_64.S:207

We must reset iterator's tags to bail out from radix_tree_next_slot()
and go to the slow-path in radix_tree_next_chunk().

Fixes: 46437f9a554f ("radix-tree: fix race in gang lookup")
Link: http://lkml.kernel.org/r/1468495196-10604-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Reported-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Acked-by: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Cc: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Cc: Hugh Dickins &lt;hughd@google.com&gt;
Cc: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: memcontrol: fix cgroup creation failure after many small jobs</title>
<updated>2016-07-23T01:25:54+00:00</updated>
<author>
<name>Johannes Weiner</name>
<email>hannes@cmpxchg.org</email>
</author>
<published>2016-07-20T22:44:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=73f576c04b9410ed19660f74f97521bee6e1c546'/>
<id>73f576c04b9410ed19660f74f97521bee6e1c546</id>
<content type='text'>
The memory controller has quite a bit of state that usually outlives the
cgroup and pins its CSS until said state disappears.  At the same time
it imposes a 16-bit limit on the CSS ID space to economically store IDs
in the wild.  Consequently, when we use cgroups to contain frequent but
small and short-lived jobs that leave behind some page cache, we quickly
run into the 64k limitations of outstanding CSSs.  Creating a new cgroup
fails with -ENOSPC while there are only a few, or even no user-visible
cgroups in existence.

Although pinning CSSs past cgroup removal is common, there are only two
instances that actually need an ID after a cgroup is deleted: cache
shadow entries and swapout records.

Cache shadow entries reference the ID weakly and can deal with the CSS
having disappeared when it's looked up later.  They pose no hurdle.

Swap-out records do need to pin the css to hierarchically attribute
swapins after the cgroup has been deleted; though the only pages that
remain swapped out after offlining are tmpfs/shmem pages.  And those
references are under the user's control, so they are manageable.

This patch introduces a private 16-bit memcg ID and switches swap and
cache shadow entries over to using that.  This ID can then be recycled
after offlining when the CSS remains pinned only by objects that don't
specifically need it.

This script demonstrates the problem by faulting one cache page in a new
cgroup and deleting it again:

  set -e
  mkdir -p pages
  for x in `seq 128000`; do
    [ $((x % 1000)) -eq 0 ] &amp;&amp; echo $x
    mkdir /cgroup/foo
    echo $$ &gt;/cgroup/foo/cgroup.procs
    echo trex &gt;pages/$x
    echo $$ &gt;/cgroup/cgroup.procs
    rmdir /cgroup/foo
  done

When run on an unpatched kernel, we eventually run out of possible IDs
even though there are no visible cgroups:

  [root@ham ~]# ./cssidstress.sh
  [...]
  65000
  mkdir: cannot create directory '/cgroup/foo': No space left on device

After this patch, the IDs get released upon cgroup destruction and the
cache and css objects get released once memory reclaim kicks in.

[hannes@cmpxchg.org: init the IDR]
  Link: http://lkml.kernel.org/r/20160621154601.GA22431@cmpxchg.org
Fixes: b2052564e66d ("mm: memcontrol: continue cache reclaim from offlined groups")
Link: http://lkml.kernel.org/r/20160617162516.GD19084@cmpxchg.org
Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reported-by: John Garcia &lt;john.garcia@mesosphere.io&gt;
Reviewed-by: Vladimir Davydov &lt;vdavydov@virtuozzo.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Nikolay Borisov &lt;kernel@kyup.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[3.19+]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The memory controller has quite a bit of state that usually outlives the
cgroup and pins its CSS until said state disappears.  At the same time
it imposes a 16-bit limit on the CSS ID space to economically store IDs
in the wild.  Consequently, when we use cgroups to contain frequent but
small and short-lived jobs that leave behind some page cache, we quickly
run into the 64k limitations of outstanding CSSs.  Creating a new cgroup
fails with -ENOSPC while there are only a few, or even no user-visible
cgroups in existence.

Although pinning CSSs past cgroup removal is common, there are only two
instances that actually need an ID after a cgroup is deleted: cache
shadow entries and swapout records.

Cache shadow entries reference the ID weakly and can deal with the CSS
having disappeared when it's looked up later.  They pose no hurdle.

Swap-out records do need to pin the css to hierarchically attribute
swapins after the cgroup has been deleted; though the only pages that
remain swapped out after offlining are tmpfs/shmem pages.  And those
references are under the user's control, so they are manageable.

This patch introduces a private 16-bit memcg ID and switches swap and
cache shadow entries over to using that.  This ID can then be recycled
after offlining when the CSS remains pinned only by objects that don't
specifically need it.

This script demonstrates the problem by faulting one cache page in a new
cgroup and deleting it again:

  set -e
  mkdir -p pages
  for x in `seq 128000`; do
    [ $((x % 1000)) -eq 0 ] &amp;&amp; echo $x
    mkdir /cgroup/foo
    echo $$ &gt;/cgroup/foo/cgroup.procs
    echo trex &gt;pages/$x
    echo $$ &gt;/cgroup/cgroup.procs
    rmdir /cgroup/foo
  done

When run on an unpatched kernel, we eventually run out of possible IDs
even though there are no visible cgroups:

  [root@ham ~]# ./cssidstress.sh
  [...]
  65000
  mkdir: cannot create directory '/cgroup/foo': No space left on device

After this patch, the IDs get released upon cgroup destruction and the
cache and css objects get released once memory reclaim kicks in.

[hannes@cmpxchg.org: init the IDR]
  Link: http://lkml.kernel.org/r/20160621154601.GA22431@cmpxchg.org
Fixes: b2052564e66d ("mm: memcontrol: continue cache reclaim from offlined groups")
Link: http://lkml.kernel.org/r/20160617162516.GD19084@cmpxchg.org
Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reported-by: John Garcia &lt;john.garcia@mesosphere.io&gt;
Reviewed-by: Vladimir Davydov &lt;vdavydov@virtuozzo.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Nikolay Borisov &lt;kernel@kyup.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[3.19+]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vlan: use a valid default mtu value for vlan over macsec</title>
<updated>2016-07-17T03:15:02+00:00</updated>
<author>
<name>Paolo Abeni</name>
<email>pabeni@redhat.com</email>
</author>
<published>2016-07-14T16:00:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=18d3df3eab23796d7f852f9c6bb60962b8372ced'/>
<id>18d3df3eab23796d7f852f9c6bb60962b8372ced</id>
<content type='text'>
macsec can't cope with mtu frames which need vlan tag insertion, and
vlan device set the default mtu equal to the underlying dev's one.
By default vlan over macsec devices use invalid mtu, dropping
all the large packets.
This patch adds a netif helper to check if an upper vlan device
needs mtu reduction. The helper is used during vlan devices
initialization to set a valid default and during mtu updating to
forbid invalid, too bit, mtu values.
The helper currently only check if the lower dev is a macsec device,
if we get more users, we need to update only the helper (possibly
reserving an additional IFF bit).

Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
macsec can't cope with mtu frames which need vlan tag insertion, and
vlan device set the default mtu equal to the underlying dev's one.
By default vlan over macsec devices use invalid mtu, dropping
all the large packets.
This patch adds a netif helper to check if an upper vlan device
needs mtu reduction. The helper is used during vlan devices
initialization to set a valid default and during mtu updating to
forbid invalid, too bit, mtu values.
The helper currently only check if the lower dev is a macsec device,
if we get more users, we need to update only the helper (possibly
reserving an additional IFF bit).

Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: thp: refix false positive BUG in page_move_anon_rmap()</title>
<updated>2016-07-15T05:54:27+00:00</updated>
<author>
<name>Hugh Dickins</name>
<email>hughd@google.com</email>
</author>
<published>2016-07-14T19:07:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5a49973d7143ebbabd76e1dcd69ee42e349bb7b9'/>
<id>5a49973d7143ebbabd76e1dcd69ee42e349bb7b9</id>
<content type='text'>
The VM_BUG_ON_PAGE in page_move_anon_rmap() is more trouble than it's
worth: the syzkaller fuzzer hit it again.  It's still wrong for some THP
cases, because linear_page_index() was never intended to apply to
addresses before the start of a vma.

That's easily fixed with a signed long cast inside linear_page_index();
and Dmitry has tested such a patch, to verify the false positive.  But
why extend linear_page_index() just for this case? when the avoidance in
page_move_anon_rmap() has already grown ugly, and there's no reason for
the check at all (nothing else there is using address or index).

Remove address arg from page_move_anon_rmap(), remove VM_BUG_ON_PAGE,
remove CONFIG_DEBUG_VM PageTransHuge adjustment.

And one more thing: should the compound_head(page) be done inside or
outside page_move_anon_rmap()? It's usually pushed down to the lowest
level nowadays (and mm/memory.c shows no other explicit use of it), so I
think it's better done in page_move_anon_rmap() than by caller.

Fixes: 0798d3c022dc ("mm: thp: avoid false positive VM_BUG_ON_PAGE in page_move_anon_rmap()")
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1607120444540.12528@eggly.anvils
Signed-off-by: Hugh Dickins &lt;hughd@google.com&gt;
Reported-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[4.5+]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The VM_BUG_ON_PAGE in page_move_anon_rmap() is more trouble than it's
worth: the syzkaller fuzzer hit it again.  It's still wrong for some THP
cases, because linear_page_index() was never intended to apply to
addresses before the start of a vma.

That's easily fixed with a signed long cast inside linear_page_index();
and Dmitry has tested such a patch, to verify the false positive.  But
why extend linear_page_index() just for this case? when the avoidance in
page_move_anon_rmap() has already grown ugly, and there's no reason for
the check at all (nothing else there is using address or index).

Remove address arg from page_move_anon_rmap(), remove VM_BUG_ON_PAGE,
remove CONFIG_DEBUG_VM PageTransHuge adjustment.

And one more thing: should the compound_head(page) be done inside or
outside page_move_anon_rmap()? It's usually pushed down to the lowest
level nowadays (and mm/memory.c shows no other explicit use of it), so I
think it's better done in page_move_anon_rmap() than by caller.

Fixes: 0798d3c022dc ("mm: thp: avoid false positive VM_BUG_ON_PAGE in page_move_anon_rmap()")
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1607120444540.12528@eggly.anvils
Signed-off-by: Hugh Dickins &lt;hughd@google.com&gt;
Reported-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[4.5+]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: thp: move pmd check inside ptl for freeze_page()</title>
<updated>2016-07-15T05:54:27+00:00</updated>
<author>
<name>Naoya Horiguchi</name>
<email>n-horiguchi@ah.jp.nec.com</email>
</author>
<published>2016-07-14T19:07:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=33f4751e99601b7bfd1d66aedabd3ee9140922de'/>
<id>33f4751e99601b7bfd1d66aedabd3ee9140922de</id>
<content type='text'>
I found a race condition triggering VM_BUG_ON() in freeze_page(), when
running a testcase with 3 processes:
  - process 1: keep writing thp,
  - process 2: keep clearing soft-dirty bits from virtual address of process 1
  - process 3: call migratepages for process 1,

The kernel message is like this:

  kernel BUG at /src/linux-dev/mm/huge_memory.c:3096!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: cfg80211 rfkill crc32c_intel ppdev serio_raw pcspkr virtio_balloon virtio_console parport_pc parport pvpanic acpi_cpufreq tpm_tis tpm i2c_piix4 virtio_blk virtio_net ata_generic pata_acpi floppy virtio_pci virtio_ring virtio
  CPU: 0 PID: 28863 Comm: migratepages Not tainted 4.6.0-v4.6-160602-0827-+ #2
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff880037320000 ti: ffff88007cdd0000 task.ti: ffff88007cdd0000
  RIP: 0010:[&lt;ffffffff811f8e06&gt;]  [&lt;ffffffff811f8e06&gt;] split_huge_page_to_list+0x496/0x590
  RSP: 0018:ffff88007cdd3b70  EFLAGS: 00010202
  RAX: 0000000000000001 RBX: ffff88007c7b88c0 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000700000200 RDI: ffffea0003188000
  RBP: ffff88007cdd3bb8 R08: 0000000000000001 R09: 00003ffffffff000
  R10: ffff880000000000 R11: ffffc000001fffff R12: ffffea0003188000
  R13: ffffea0003188000 R14: 0000000000000000 R15: 0400000000000080
  FS:  00007f8ec241d740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000             CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f8ec1f3ed20 CR3: 000000003707b000 CR4: 00000000000006f0
  Call Trace:
    ? list_del+0xd/0x30
    queue_pages_pte_range+0x4d1/0x590
    __walk_page_range+0x204/0x4e0
    walk_page_range+0x71/0xf0
    queue_pages_range+0x75/0x90
    ? queue_pages_hugetlb+0x190/0x190
    ? new_node_page+0xc0/0xc0
    ? change_prot_numa+0x40/0x40
    migrate_to_node+0x71/0xd0
    do_migrate_pages+0x1c3/0x210
    SyS_migrate_pages+0x261/0x290
    entry_SYSCALL_64_fastpath+0x1a/0xa4
  Code: e8 b0 87 fb ff 0f 0b 48 c7 c6 30 32 9f 81 e8 a2 87 fb ff 0f 0b 48 c7 c6 b8 46 9f 81 e8 94 87 fb ff 0f 0b 85 c0 0f 84 3e fd ff ff &lt;0f&gt; 0b 85 c0 0f 85 a6 00 00 00 48 8b 75 c0 4c 89 f7 41 be f0 ff
  RIP   split_huge_page_to_list+0x496/0x590

I'm not sure of the full scenario of the reproduction, but my debug
showed that split_huge_pmd_address(freeze=true) returned without running
main code of pmd splitting because pmd_present(*pmd) in precheck somehow
returned 0.  If this happens, the subsequent try_to_unmap() fails and
returns non-zero (because page_mapcount() still &gt; 0), and finally
VM_BUG_ON() fires.  This patch tries to fix it by prechecking pmd state
inside ptl.

Link: http://lkml.kernel.org/r/1466990929-7452-1-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi &lt;n-horiguchi@ah.jp.nec.com&gt;
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I found a race condition triggering VM_BUG_ON() in freeze_page(), when
running a testcase with 3 processes:
  - process 1: keep writing thp,
  - process 2: keep clearing soft-dirty bits from virtual address of process 1
  - process 3: call migratepages for process 1,

The kernel message is like this:

  kernel BUG at /src/linux-dev/mm/huge_memory.c:3096!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: cfg80211 rfkill crc32c_intel ppdev serio_raw pcspkr virtio_balloon virtio_console parport_pc parport pvpanic acpi_cpufreq tpm_tis tpm i2c_piix4 virtio_blk virtio_net ata_generic pata_acpi floppy virtio_pci virtio_ring virtio
  CPU: 0 PID: 28863 Comm: migratepages Not tainted 4.6.0-v4.6-160602-0827-+ #2
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff880037320000 ti: ffff88007cdd0000 task.ti: ffff88007cdd0000
  RIP: 0010:[&lt;ffffffff811f8e06&gt;]  [&lt;ffffffff811f8e06&gt;] split_huge_page_to_list+0x496/0x590
  RSP: 0018:ffff88007cdd3b70  EFLAGS: 00010202
  RAX: 0000000000000001 RBX: ffff88007c7b88c0 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000700000200 RDI: ffffea0003188000
  RBP: ffff88007cdd3bb8 R08: 0000000000000001 R09: 00003ffffffff000
  R10: ffff880000000000 R11: ffffc000001fffff R12: ffffea0003188000
  R13: ffffea0003188000 R14: 0000000000000000 R15: 0400000000000080
  FS:  00007f8ec241d740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000             CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f8ec1f3ed20 CR3: 000000003707b000 CR4: 00000000000006f0
  Call Trace:
    ? list_del+0xd/0x30
    queue_pages_pte_range+0x4d1/0x590
    __walk_page_range+0x204/0x4e0
    walk_page_range+0x71/0xf0
    queue_pages_range+0x75/0x90
    ? queue_pages_hugetlb+0x190/0x190
    ? new_node_page+0xc0/0xc0
    ? change_prot_numa+0x40/0x40
    migrate_to_node+0x71/0xd0
    do_migrate_pages+0x1c3/0x210
    SyS_migrate_pages+0x261/0x290
    entry_SYSCALL_64_fastpath+0x1a/0xa4
  Code: e8 b0 87 fb ff 0f 0b 48 c7 c6 30 32 9f 81 e8 a2 87 fb ff 0f 0b 48 c7 c6 b8 46 9f 81 e8 94 87 fb ff 0f 0b 85 c0 0f 84 3e fd ff ff &lt;0f&gt; 0b 85 c0 0f 85 a6 00 00 00 48 8b 75 c0 4c 89 f7 41 be f0 ff
  RIP   split_huge_page_to_list+0x496/0x590

I'm not sure of the full scenario of the reproduction, but my debug
showed that split_huge_pmd_address(freeze=true) returned without running
main code of pmd splitting because pmd_present(*pmd) in precheck somehow
returned 0.  If this happens, the subsequent try_to_unmap() fails and
returns non-zero (because page_mapcount() still &gt; 0), and finally
VM_BUG_ON() fires.  This patch tries to fix it by prechecking pmd state
inside ptl.

Link: http://lkml.kernel.org/r/1466990929-7452-1-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi &lt;n-horiguchi@ah.jp.nec.com&gt;
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2016-07-13T20:33:38+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-07-13T20:33:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a7bf89a1b14c6ebae233275e704587146fbaa5c1'/>
<id>a7bf89a1b14c6ebae233275e704587146fbaa5c1</id>
<content type='text'>
Pull x86 fixes from Ingo Molnar:
 "This contains three commits to fix memory corruption bugs with certain
  Apple AirPort cards, plus a fix for a X86_BUG() ID definitions collision
  bug in asm/cpufeatures.h"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/quirks: Add early quirk to reset Apple AirPort card
  x86/quirks: Reintroduce scanning of secondary buses
  x86/quirks: Apply nvidia_bugs quirk only on root bus
  x86/cpu: Fix duplicated X86_BUG(9) macro
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 fixes from Ingo Molnar:
 "This contains three commits to fix memory corruption bugs with certain
  Apple AirPort cards, plus a fix for a X86_BUG() ID definitions collision
  bug in asm/cpufeatures.h"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/quirks: Add early quirk to reset Apple AirPort card
  x86/quirks: Reintroduce scanning of secondary buses
  x86/quirks: Apply nvidia_bugs quirk only on root bus
  x86/cpu: Fix duplicated X86_BUG(9) macro
</pre>
</div>
</content>
</entry>
</feed>
