nbd: fsync and kill block device on shutdown

commit 3a2d63f87989e01437ba994df5f297528c353d7d upstream.

There are two problems with shutdown in the NBD driver.

1: Receiving the NBD_DISCONNECT ioctl does not sync the filesystem.

   This patch adds the sync operation into __nbd_ioctl()'s
   NBD_DISCONNECT handler.  This is useful because BLKFLSBUF is restricted
   to processes that have CAP_SYS_ADMIN, and the NBD client may not
   possess it (fsync of the block device does not sync the filesystem,
   either).

2: Once we clear the socket we have no guarantee that later reads will
   come from the same backing storage.

   The patch adds calls to kill_bdev() in __nbd_ioctl()'s socket
   clearing code so the page cache is cleaned, lest reads that hit on the
   page cache will return stale data from the previously-accessible disk.

Example:

    # qemu-nbd -r -c/dev/nbd0 /dev/sr0
    # file -s /dev/nbd0
    /dev/stdin: # UDF filesystem data (version 1.5) etc.
    # qemu-nbd -d /dev/nbd0
    # qemu-nbd -r -c/dev/nbd0 /dev/sda
    # file -s /dev/nbd0
    /dev/stdin: # UDF filesystem data (version 1.5) etc.

While /dev/sda has:

    # file -s /dev/sda
    /dev/sda: x86 boot sector; etc.

Change-Id: I81010ca2741eb9d6287002ff6a9b88c6803a3e57
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Paul Clements <Paul.Clements@steeleye.com>
Cc: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2:
 - Adjusted context
 - s/\bnbd\b/lo/
 - Incorporate export of kill_bdev() from commit ff01bb483265
   ('fs: move code out of buffer.c')]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[hq: Backported to 3.4: Adjusted context]
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers: hv: switch to use mb() instead of smp_mb()

commit 35848f68b07df3f917cb13fc3c134718669f569b upstream.

Even if guest were compiled without SMP support, it could not assume that host
wasn't. So switch to use mb() instead of smp_mb() to force memory barriers for
UP guest.

Change-Id: I0e8189eb22a4e0f2b8c42b15b148061860b676f5
Signed-off-by: Jason Wang <jasowang@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2:
 - Drop changes to functions that don't exist here
 - hv_ringbuffer_write() has only a write memory barrier]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[hq: Backported to 3.4:
 - Add the change in hv_ringbuffer_read]
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drm/i915/sdvo: clean up connectors on intel_sdvo_init() failures

commit d0ddfbd3d1346c1f481ec2289eef350cdba64b42 upstream.

Any failures in intel_sdvo_init() after the intel_sdvo_setup_output() call
left behind ghost connectors, attached (with a dangling pointer) to the
sdvo that has been cleaned up and freed. Properly destroy any connectors
attached to the encoder.

Change-Id: I01366d82a73a1ee62a17e8d8f3ccc76fd8255fe3
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=46381
CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: bjo@nord-west.org
[danvet: added a comment to explain why we need to clean up connectors
even when sdvo_output_setup fails.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drm: fix documentation for drm_crtc_set_mode()

commit 4c9287c6009b37754c42e0ba73a4cc79de92d8f8 upstream.

x and y parameters are offsets, not width/height

Change-Id: I3789541e5fe17273f0f5d37b44e55e9e8026e7b3
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>