Pull block fixes from Jens Axboe:
 "Alright, this time from 10K up in the air.

  Collection of fixes that have been queued up since the merge window
  opened, hence postponed until later in the cycle.  The pull request
  contains:

   - A bunch of fixes for the xen blk front/back driver.

   - A round of fixes for the new IBM RamSan driver, fixing various
     nasty issues.

   - Fixes for multiple drives from Wei Yongjun, bad handling of return
     values and wrong pointer math.

   - A fix for loop properly killing partitions when being detached."

* tag 'for-linus-20130331' of git://git.kernel.dk/linux-block: (25 commits)
  mg_disk: fix error return code in mg_probe()
  rsxx: remove unused variable
  rsxx: enable error return of rsxx_eeh_save_issued_dmas()
  block: removes dynamic allocation on stack
  Block: blk-flush: Fixed indent code style
  cciss: fix invalid use of sizeof in cciss_find_cfgtables()
  loop: cleanup partitions when detaching loop device
  loop: fix error return code in loop_add()
  mtip32xx: fix error return code in mtip_pci_probe()
  xen-blkfront: remove frame list from blk_shadow
  xen-blkfront: pre-allocate pages for requests
  xen-blkback: don't store dev_bus_addr
  xen-blkfront: switch from llist to list
  xen-blkback: fix foreach_grant_safe to handle empty lists
  xen-blkfront: replace kmalloc and then memcpy with kmemdup
  xen-blkback: fix dispatch_rw_block_io() error path
  rsxx: fix missing unlock on error return in rsxx_eeh_remap_dmas()
  Adding in EEH support to the IBM FlashSystem 70/80 device driver
  block: IBM RamSan 70/80 error message bug fix.
  block: IBM RamSan 70/80 branding changes.
  ...

This reverts commit 6aa9707099c4b25700940eb3d016f16c4434360d.

Commit 6aa9707099c4 ("lockdep: check that no locks held at freeze time")
causes problems with NFS root filesystems.  The failures were noticed on
OMAP2 and 3 boards during kernel init:

  [ BUG: swapper/0/1 still has locks held! ]
  3.9.0-rc3-00344-ga937536 #1 Not tainted
  -------------------------------------
  1 lock held by swapper/0/1:
   #0:  (&type->s_umount_key#13/1){+.+.+.}, at: [<c011e84c>] sget+0x248/0x574

  stack backtrace:
    rpc_wait_bit_killable
    __wait_on_bit
    out_of_line_wait_on_bit
    __rpc_execute
    rpc_run_task
    rpc_call_sync
    nfs_proc_get_root
    nfs_get_root
    nfs_fs_mount_common
    nfs_try_mount
    nfs_fs_mount
    mount_fs
    vfs_kern_mount
    do_mount
    sys_mount
    do_mount_root
    mount_root
    prepare_namespace
    kernel_init_freeable
    kernel_init

Although the rootfs mounts, the system is unstable.  Here's a transcript
from a PM test:

  http://www.pwsan.com/omap/testlogs/test_v3.9-rc3/20130317194234/pm/37xxevm/37xxevm_log.txt

Here's what the test log should look like:

  http://www.pwsan.com/omap/testlogs/test_v3.8/20130218214403/pm/37xxevm/37xxevm_log.txt

Mailing list discussion is here:

  http://lkml.org/lkml/2013/3/4/221

Deal with this for v3.9 by reverting the problem commit, until folks can
figure out the right long-term course of action.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: <maciej.rutecki@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ben Chan <benchan@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit 186930500985 ("mm: introduce VM_POPULATE flag to
better deal with racy userspace programs").

VM_POPULATE only has any effect when userspace plays racy games with
vmas by trying to unmap and remap memory regions that mmap or mlock are
operating on.

Also, the only effect of VM_POPULATE when userspace plays such games is
that it avoids populating new memory regions that get remapped into the
address range that was being operated on by the original mmap or mlock
calls.

Let's remove VM_POPULATE as there isn't any strong argument to mandate a
new vm_flag.

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull USB fixes from Greg Kroah-Hartman:
 "Here are some USB fixes to resolve issues reported recently, as well
  as a new device id for the ftdi_sio driver."

* tag 'usb-3.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: ftdi_sio: Add support for Mitsubishi FX-USB-AW/-BD
  usb: Fix compile error by selecting USB_OTG_UTILS
  USB: serial: fix hang when opening port
  USB: EHCI: fix bug in iTD/siTD DMA pool allocation
  xhci: Don't warn on empty ring for suspended devices.
  usb: xhci: Fix TRB transfer length macro used for Event TRB.
  usb/acpi: binding xhci root hub usb port with ACPI
  usb: add find_raw_port_number callback to struct hc_driver()
  usb: xhci: fix build warning

Pull char/misc driver fixes from Greg Kroah-Hartman:
 "Here are some small char/misc driver fixes that resolve issues
  recently reported against the 3.9-rc kernels.  All have been in
  linux-next for a while."

* tag 'char-misc-3.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  VMCI: Fix process-to-process DRGAMs.
  mei: ME hardware reset needs to be synchronized
  mei: add mei_stop function to stop mei device
  extcon: max77693: Initialize register of MUIC device to bring up it without platform data
  extcon: max77693: Fix bug of wrong pointer when platform data is not used
  extcon: max8997: Check the pointer of platform data to protect null pointer error

Pull userns fixes from Eric W Biederman:
 "The bulk of the changes are fixing the worst consequences of the user
  namespace design oversight in not considering what happens when one
  namespace starts off as a clone of another namespace, as happens with
  the mount namespace.

  The rest of the changes are just plain bug fixes.

  Many thanks to Andy Lutomirski for pointing out many of these issues."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns: Restrict when proc and sysfs can be mounted
  ipc: Restrict mounting the mqueue filesystem
  vfs: Carefully propogate mounts across user namespaces
  vfs: Add a mount flag to lock read only bind mounts
  userns:  Don't allow creation if the user is chrooted
  yama:  Better permission check for ptraceme
  pid: Handle the exit of a multi-threaded init.
  scm: Require CAP_SYS_ADMIN over the current pidns to spoof pids.

Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
 "This is mostly just the last stragglers of the regression bugs that
  this merge window had.  There are also two bug-fixes: one that adds an
  extra layer of security, and a regression fix for a change that was
  added in v3.7 (the v1 was faulty, the v2 works).

   - Regression fixes for C-and-P states not being parsed properly.
   - Fix possible security issue with guests triggering DoS via
     non-assigned MSI-Xs.
   - Fix regression (introduced in v3.7) with raising an event (v2).
   - Fix hastily introduced band-aid during c0 for the CR3 blowup."

* tag 'stable/for-linus-3.9-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/events: avoid race with raising an event in unmask_evtchn()
  xen/mmu: Move the setting of pvops.write_cr3 to later phase in bootup.
  xen/acpi-stub: Disable it b/c the acpi_processor_add is no longer called.
  xen-pciback: notify hypervisor about devices intended to be assigned to guests
  xen/acpi-processor: Don't dereference struct acpi_processor on all CPUs.

Only allow unprivileged mounts of proc and sysfs if they are already
mounted when the user namespace is created.

proc and sysfs are interesting because they have content that is
per namespace, and so fresh mounts are needed when new namespaces
are created while at the same time proc and sysfs have content that
is shared between every instance.

Respect the policy of who may see the shared content of proc and sysfs
by only allowing new mounts if there was an existing mount at the time
the user namespace was created.

In practice there are only two interesting cases: proc and sysfs are
mounted at their usual places, proc and sysfs are not mounted at all
(some form of mount namespace jail).

Cc: stable@vger.kernel.org
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

When a read-only bind mount is copied from mount namespace in a higher
privileged user namespace to a mount namespace in a lesser privileged
user namespace, it should not be possible to remove the the read-only
restriction.

Add a MNT_LOCK_READONLY mount flag to indicate that a mount must
remain read-only.

CC: stable@vger.kernel.org
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Guarantee that the policy of which files may be access that is
established by setting the root directory will not be violated
by user namespaces by verifying that the root directory points
to the root of the mount namespace at the time of user namespace
creation.

Changing the root is a privileged operation, and as a matter of policy
it serves to limit unprivileged processes to files below the current
root directory.

For reasons of simplicity and comprehensibility the privilege to
change the root directory is gated solely on the CAP_SYS_CHROOT
capability in the user namespace.  Therefore when creating a user
namespace we must ensure that the policy of which files may be access
can not be violated by changing the root directory.

Anyone who runs a processes in a chroot and would like to use user
namespace can setup the same view of filesystems with a mount
namespace instead.  With this result that this is not a practical
limitation for using user namespaces.

Cc: stable@vger.kernel.org
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>