linux-stable.git/include, branch v4.4.19

SUNRPC: Don't allocate a full sockaddr_storage for tracing

2016-08-20T16:09:26+00:00

commit db1bb44c4c7e8d49ed674dc59e5222d99c698088 upstream.

We're always tracing IPv4 or IPv6 addresses, so we can save a lot
of space on the ringbuffer by allocating the correct sockaddr size.

Signed-off-by: Trond Myklebust 
Fixes: 83a712e0afef "sunrpc: add some tracepoints around ..."
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

target: Fix ordered task CHECK_CONDITION early exception handling

2016-08-20T16:09:26+00:00

commit 410c29dfbfdf73d0d0b5d14a21868ab038eca703 upstream.

If a Simple command is sent with a failure, target_setup_cmd_from_cdb
returns with TCM_UNSUPPORTED_SCSI_OPCODE or TCM_INVALID_CDB_FIELD.

So in the cases where target_setup_cmd_from_cdb returns an error, we
never get far enough to call target_execute_cmd to increment simple_cmds.
Since simple_cmds isn't incremented, the result of the failure from
target_setup_cmd_from_cdb causes transport_generic_request_failure to
decrement simple_cmds, due to call to transport_complete_task_attr.

With this dev->simple_cmds or dev->dev_ordered_sync is now -1, not 0.
So when a subsequent command with an Ordered Task is sent, it causes
a hang, since dev->simple_cmds is at -1.

Tested-by: Bryant G. Ly 
Signed-off-by: Bryant G. Ly 
Tested-by: Michael Cyr 
Signed-off-by: Michael Cyr 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix max_unmap_lba_count calc overflow

2016-08-20T16:09:26+00:00

commit ea263c7fada4af8ec7fe5fcfd6e7d7705a89351b upstream.

max_discard_sectors only 32bits, and some non scsi backend
devices will set this to the max 0xffffffff, so we can end up
overflowing during the max_unmap_lba_count calculation.

This fixes a regression caused by my patch:

commit 8a9ebe717a133ba7bc90b06047f43cc6b8bcb8b3
Author: Mike Christie 
Date:   Mon Jan 18 14:09:27 2016 -0600

    target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors

which can result in extra discards being sent to due the overflow
causing max_unmap_lba_count to be smaller than what the backing
device can actually support.

Signed-off-by: Mike Christie 
Reviewed-by: Bart Van Assche 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix ordered task target_setup_cmd_from_cdb exception hang

2016-08-20T16:09:26+00:00

commit dff0ca9ea7dc8be2181a62df4a722c32ce68ff4a upstream.

If a command with a Simple task attribute is failed due to a Unit
Attention, then a subsequent command with an Ordered task attribute
will hang forever.  The reason for this is that the Unit Attention
status is checked for in target_setup_cmd_from_cdb, before the call
to target_execute_cmd, which calls target_handle_task_attr, which
in turn increments dev->simple_cmds.

However, transport_generic_request_failure still calls
transport_complete_task_attr, which will decrement dev->simple_cmds.
In this case, simple_cmds is now -1.  So when a command with the
Ordered task attribute is sent, target_handle_task_attr sees that
dev->simple_cmds is not 0, so it decides it can't execute the
command until all the (nonexistent) Simple commands have completed.

Reported-by: Michael Cyr 
Tested-by: Michael Cyr 
Reported-by: Bryant G. Ly 
Tested-by: Bryant G. Ly 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

IB/mlx5: Fix post send fence logic

2016-08-20T16:09:25+00:00

commit c9b254955b9f8814966f5dabd34c39d0e0a2b437 upstream.

If the caller specified IB_SEND_FENCE in the send flags of the work
request and no previous work request stated that the successive one
should be fenced, the work request would be executed without a fence.
This could result in RDMA read or atomic operations failure due to a MR
being invalidated. Fix this by adding the mlx5 enumeration for fencing
RDMA/atomic operations and fix the logic to apply this.

Fixes: e126ba97dba9 ('mlx5: Add driver for Mellanox Connect-IB adapters')
Signed-off-by: Eli Cohen 
Signed-off-by: Leon Romanovsky 
Signed-off-by: Doug Ledford 
Signed-off-by: Greg Kroah-Hartman

IB/mlx5: Fix MODIFY_QP command input structure

2016-08-20T16:09:24+00:00

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 
Signed-off-by: Leon Romanovsky 
Signed-off-by: Doug Ledford 
Signed-off-by: Greg Kroah-Hartman

block: fix bdi vs gendisk lifetime mismatch

2016-08-20T16:09:24+00:00

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:
  [] dump_stack+0x63/0x87
  [] __warn+0xd1/0xf0
  [] warn_slowpath_fmt+0x5f/0x80
  [] sysfs_warn_dup+0x64/0x80
  [] sysfs_create_dir_ns+0x7e/0x90
  [] kobject_add_internal+0xaa/0x320
  [] ? vsnprintf+0x34e/0x4d0
  [] kobject_add+0x75/0xd0
  [] ? mutex_lock+0x12/0x2f
  [] device_add+0x125/0x610
  [] device_create_groups_vargs+0xd8/0x100
  [] device_create_vargs+0x1c/0x20
  [] bdi_register+0x8c/0x180
  [] bdi_register_dev+0x27/0x30
  [] add_disk+0x175/0x4a0

Reported-by: Yi Zhang 
Tested-by: Yi Zhang 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman 

Fixed up missing 0 return in bdi_register_owner().

Signed-off-by: Jens Axboe

block: add missing group association in bio-cloning functions

2016-08-20T16:09:24+00:00

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 
Reviewed-by: Nikolay Borisov 
Reviewed-by: Jeff Moyer 
Acked-by: Tejun Heo 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

mm: memcontrol: fix cgroup creation failure after many small jobs

2016-08-16T07:30:51+00:00

commit 73f576c04b9410ed19660f74f97521bee6e1c546 upstream.

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 ] && echo $x
    mkdir /cgroup/foo
    echo $$ >/cgroup/foo/cgroup.procs
    echo trex >pages/$x
    echo $$ >/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 
Reported-by: John Garcia 
Reviewed-by: Vladimir Davydov 
Acked-by: Tejun Heo 
Cc: Nikolay Borisov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Michal Hocko 
Signed-off-by: Greg Kroah-Hartman

devpts: clean up interface to pty drivers

2016-08-16T07:30:49+00:00

commit 67245ff332064c01b760afa7a384ccda024bfd24 upstream.

This gets rid of the horrible notion of having that

    struct inode *ptmx_inode

be the linchpin of the interface between the pty code and devpts.

By de-emphasizing the ptmx inode, a lot of things actually get cleaner,
and we will have a much saner way forward.  In particular, this will
allow us to associate with any particular devpts instance at open-time,
and not be artificially tied to one particular ptmx inode.

The patch itself is actually fairly straightforward, and apart from some
locking and return path cleanups it's pretty mechanical:

 - the interfaces that devpts exposes all take "struct pts_fs_info *"
   instead of "struct inode *ptmx_inode" now.

   NOTE! The "struct pts_fs_info" thing is a completely opaque structure
   as far as the pty driver is concerned: it's still declared entirely
   internally to devpts. So the pty code can't actually access it in any
   way, just pass it as a "cookie" to the devpts code.

 - the "look up the pts fs info" is now a single clear operation, that
   also does the reference count increment on the pts superblock.

   So "devpts_add/del_ref()" is gone, and replaced by a "lookup and get
   ref" operation (devpts_get_ref(inode)), along with a "put ref" op
   (devpts_put_ref()).

 - the pty master "tty->driver_data" field now contains the pts_fs_info,
   not the ptmx inode.

 - because we don't care about the ptmx inode any more as some kind of
   base index, the ref counting can now drop the inode games - it just
   gets the ref on the superblock.

 - the pts_fs_info now has a back-pointer to the super_block. That's so
   that we can easily look up the information we actually need. Although
   quite often, the pts fs info was actually all we wanted, and not having
   to look it up based on some magical inode makes things more
   straightforward.

In particular, now that "devpts_get_ref(inode)" operation should really
be the *only* place we need to look up what devpts instance we're
associated with, and we do it exactly once, at ptmx_open() time.

The other side of this is that one ptmx node could now be associated
with multiple different devpts instances - you could have a single
/dev/ptmx node, and then have multiple mount namespaces with their own
instances of devpts mounted on /dev/pts/.  And that's all perfectly sane
in a model where we just look up the pts instance at open time.

This will eventually allow us to get rid of our odd single-vs-multiple
pts instance model, but this patch in itself changes no semantics, only
an internal binding model.

Cc: Eric Biederman 
Cc: Peter Anvin 
Cc: Andy Lutomirski 
Cc: Al Viro 
Cc: Peter Hurley 
Cc: Serge Hallyn 
Cc: Willy Tarreau 
Cc: Aurelien Jarno 
Cc: Alan Cox 
Cc: Jann Horn 
Cc: Greg KH 
Cc: Jiri Slaby 
Cc: Florian Weimer 
Signed-off-by: Linus Torvalds 
Cc: Francesco Ruggeri 
Cc: "Herton R. Krzesinski" 
Signed-off-by: Greg Kroah-Hartman