Zesty update to v4.9.1 stable release

SRU Justification

    Impact:
       The upstream process for stable tree updates is quite similar
       in scope to the Ubuntu SRU process, e.g., each patch has to
       demonstrably fix a bug, and each patch is vetted by upstream
       by originating either directly from a mainline/stable Linux tree or
       a minimally backported form of that patch. The v4.9.1 upstream stable
       patch set is now available. It should be included in the Ubuntu
       kernel as well.

       git://git.kernel.org/

    TEST CASE: TBD

       The following patches from the v4.9.1 stable release shall be applied:

Revert "UBUNTU: SAUCE: (noup) ptrace: being capable wrt a process requires mapped uids/gids"
hotplug: Make register and unregister notifier API symmetric
btrfs: limit async_work allocation and worker func duration
Btrfs: fix BUG_ON in btrfs_mark_buffer_dirty
Btrfs: fix deadlock caused by fsync when logging directory entries
Btrfs: fix tree search logic when replaying directory entry deletes
Btrfs: fix relocation incorrectly dropping data references
btrfs: store and load values of stripes_min/stripes_max in balance status item
Btrfs: fix emptiness check for dirtied extent buffers at check_leaf()
Btrfs: fix qgroup rescan worker initialization
USB: serial: option: add support for Telit LE922A PIDs 0x1040, 0x1041
USB: serial: option: add dlink dwm-158
USB: serial: kl5kusb105: fix open error path
USB: cdc-acm: add device id for GW Instek AFG-125
usb: dwc3: gadget: set PCM1 field of isochronous-first TRBs
usb: hub: Fix auto-remount of safely removed or ejected USB-3 devices
usb: core: usbport: Use proper LED API to fix potential crash
usb: gadget: f_uac2: fix error handling at afunc_bind
usb: gadget: composite: correctly initialize ep->maxpacket
USB: UHCI: report non-PME wakeup signalling for Intel hardware
usbip: vudc: fix: Clear already_seen flag also for ep0
ALSA: usb-audio: Add QuickCam Communicate Deluxe/S7500 to volume_control_quirks
ALSA: hiface: Fix M2Tech hiFace driver sampling rate change
ALSA: hda/ca0132 - Add quirk for Alienware 15 R2 2016
ALSA: hda - ignore the assoc and seq when comparing pin configurations
ALSA: hda - fix headset-mic problem on a Dell laptop
ALSA: hda - Gate the mic jack on HP Z1 Gen3 AiO
ALSA: hda: when comparing pin configurations, ignore assoc in addition to seq
clk: ti: omap36xx: Work around sprz319 advisory 2.1
exec: Ensure mm->user_ns contains the execed files
fs: exec: apply CLOEXEC before changing dumpable task flags
splice: reinstate SIGPIPE/EPIPE handling
block_dev: don't test bdev->bd_contains when it is not stable
mm: Add a user_ns owner to mm_struct and fix ptrace permission checks
vfs,mm: fix return value of read() at s_maxbytes
ptrace: Capture the ptracer's creds not PT_PTRACE_CAP
ptrace: Don't allow accessing an undumpable mm
crypto: caam - fix AEAD givenc descriptors
ext4: don't lock buffer in ext4_commit_super if holding spinlock
ext4: fix mballoc breakage with 64k block size
ext4: fix stack memory corruption with 64k block size
ext4: use more strict checks for inodes_per_block on mount
ext4: fix in-superblock mount options processing
ext4: add sanity checking to count_overhead()
ext4: reject inodes with negative size
ext4: return -ENOMEM instead of success
ext4: do not perform data journaling when data is encrypted
Revert "f2fs: use percpu_counter for # of dirty pages in inode"
f2fs: set ->owner for debugfs status file's file_operations
f2fs: fix overflow due to condition check order
f2fs: fix to determine start_cp_addr by sbi->cur_cp_pack
loop: return proper error from loop_queue_rq()
nvmet: Fix possible infinite loop triggered on hot namespace removal
mm/vmscan.c: set correct defer count for shrinker
mm, page_alloc: keep pcp count and list contents in sync if struct page is corrupted
usb: gadget: composite: always set ep->mult to a sensible value
PM / OPP: Pass opp_table to dev_pm_opp_put_regulator()
PM / OPP: Don't use OPP structure outside of rcu protected section
blk-mq: Do not invoke .queue_rq() for a stopped queue
dm table: fix 'all_blk_mq' inconsistency when an empty table is loaded
dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device
dm flakey: return -EINVAL on interval bounds error in flakey_ctr()
dm crypt: mark key as invalid until properly loaded
dm rq: fix a race condition in rq_completed()
dm raid: fix discard support regression
dm space map metadata: fix 'struct sm_metadata' leak on failed create
ASoC: intel: Fix crash at suspend/resume without card registration
cifs: Fix smbencrypt() to stop pointing a scatterlist at the stack
CIFS: Fix a possible memory corruption during reconnect
CIFS: Fix missing nls unload in smb2_reconnect()
CIFS: Fix a possible double locking of mutex during reconnect
CIFS: Decrease verbosity of ioctl call
CIFS: Fix a possible memory corruption in push locks
kernel/watchdog: use nmi registers snapshot in hardlockup handler
watchdog: mei_wdt: request stop on reboot to prevent false positive event
watchdog: qcom: fix kernel panic due to external abort on non-linefetch
kernel/debug/debug_core.c: more properly delay for secondary CPUs
tpm xen: Remove bogus tpm_chip_unregister
xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing
arm/xen: Use alloc_percpu rather than __alloc_percpu
xfs: fix up xfs_swap_extent_forks inline extent handling
xfs: set AGI buffer type in xlog_recover_clear_agi_bucket
builddeb: fix cross-building to arm64 producing host-arch debs
x86/kbuild: enable modversions for symbols exported from asm
Linux 4.9.1