Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

This is an eventual replacement for vfs_submount() uses.  Unlike the
"mount" and "remount" cases, the users of that thing are not in VFS -
they are buried in various ->d_automount() instances and rather than
converting them all at once we introduce the (thankfully small and
simple) infrastructure here and deal with the prospective users in
afs, nfs, etc. parts of the series.

Here we just introduce a new constructor (fs_context_for_submount())
along with the corresponding enum constant to be put into fc->purpose
for those.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Replace do_remount_sb() with a function, reconfigure_super(), that's
fs_context aware.  The fs_context is expected to be parameterised already
and have ->root pointing to the superblock to be reconfigured.

A legacy wrapper is provided that is intended to be called from the
fs_context ops when those appear, but for now is called directly from
reconfigure_super().  This wrapper invokes the ->remount_fs() superblock op
for the moment.  It is intended that the remount_fs() op will be phased
out.

The fs_context->purpose is set to FS_CONTEXT_FOR_RECONFIGURE to indicate
that the context is being used for reconfiguration.

do_umount_root() is provided to consolidate remount-to-R/O for umount and
emergency remount by creating a context and invoking reconfiguration.

do_remount(), do_umount() and do_emergency_remount_callback() are switched
to use the new process.

[AV -- fold UMOUNT and EMERGENCY_REMOUNT in; fixes the
umount / bug, gets rid of pointless complexity]
[AV -- set ->net_ns in all cases; nfs remount will need that]
[AV -- shift security_sb_remount() call into reconfigure_super(); the callers
that didn't do security_sb_remount() have NULL fc->security anyway, so it's
a no-op for them]
Signed-off-by: David Howells <dhowells@redhat.com>
Co-developed-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Right now vfs_get_tree() calls security_sb_kern_mount() (i.e.
mount MAC) unless it gets MS_KERNMOUNT or MS_SUBMOUNT in flags.
Doing it that way is both clumsy and imprecise.

Consider the callers' tree of vfs_get_tree():
vfs_get_tree()
        <- do_new_mount()
	<- vfs_kern_mount()
		<- simple_pin_fs()
		<- vfs_submount()
		<- kern_mount_data()
		<- init_mount_tree()
		<- btrfs_mount()
			<- vfs_get_tree()
		<- nfs_do_root_mount()
			<- nfs4_try_mount()
				<- nfs_fs_mount()
					<- vfs_get_tree()
			<- nfs4_referral_mount()

do_new_mount() always does need MAC (we are guaranteed that neither
MS_KERNMOUNT nor MS_SUBMOUNT will be passed there).

simple_pin_fs(), vfs_submount() and kern_mount_data() pass explicit
flags inhibiting that check.  So does nfs4_referral_mount() (the
flags there are ulimately coming from vfs_submount()).

init_mount_tree() is called too early for anything LSM-related; it
doesn't matter whether we attempt those checks, they'll do nothing.

Finally, in case of btrfs_mount() and nfs_fs_mount(), doing MAC
is pointless - either the caller will do it, or the flags are
such that we wouldn't have done it either.

In other words, the one and only case when we want that check
done is when we are called from do_new_mount(), and there we
want it unconditionally.

So let's simply move it there.  The superblock is still locked,
so nobody is going to get access to it (via ustat(2), etc.)
until we get a chance to apply the checks - we are free to
move them to any point up to where we drop ->s_umount (in
do_new_mount_fc()).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Create an fs_context-aware version of do_new_mount().  This takes an
fs_context with a superblock already attached to it.

Make do_new_mount() use do_new_mount_fc() rather than do_new_mount(); this
allows the consolidation of the mount creation, check and add steps.

To make this work, mount_too_revealing() is changed to take a superblock
rather than a mount (which the fs_context doesn't have available), allowing
this check to be done before the mount object is created.
Signed-off-by: David Howells <dhowells@redhat.com>
Co-developed-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Roll the handling of subtypes into do_new_mount() and vfs_get_tree().  The
former determines any subtype string and hangs it off the fs_context; the
latter applies it.

Make do_new_mount() create, parameterise and commit an fs_context and
create a mount for itself rather than calling vfs_kern_mount().

[AV -- missing kstrdup()]
[AV -- ... and no kstrdup() if we get to setting ->s_submount - we
simply transfer it from fc, leaving NULL behind]
[AV -- constify ->s_submount, while we are at it]
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Create a new helper, vfs_create_mount(), that creates a detached vfsmount
object from an fs_context that has a superblock attached to it.

Almost all uses will be paired with immediately preceding vfs_get_tree();
add a helper for such combination.

Switch vfs_kern_mount() to use this.

NOTE: mild behaviour change; passing NULL as 'device name' to
something like procfs will change /proc/*/mountstats - "device none"
instead on "no device".  That is consistent with /proc/mounts et.al.

[do'h - EXPORT_SYMBOL_GPL slipped in by mistake; removed]
[AV -- remove confused comment from vfs_create_mount()]
[AV -- removed the second argument]
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Introduce a filesystem context concept to be used during superblock
creation for mount and superblock reconfiguration for remount.  This is
allocated at the beginning of the mount procedure and into it is placed:

 (1) Filesystem type.

 (2) Namespaces.

 (3) Source/Device names (there may be multiple).

 (4) Superblock flags (SB_*).

 (5) Security details.

 (6) Filesystem-specific data, as set by the mount options.

Accessor functions are then provided to set up a context, parameterise it
from monolithic mount data (the data page passed to mount(2)) and tear it
down again.

A legacy wrapper is provided that implements what will be the basic
operations, wrapping access to filesystems that aren't yet aware of the
fs_context.

Finally, vfs_kern_mount() is changed to make use of the fs_context and
mount_fs() is replaced by vfs_get_tree(), called from vfs_kern_mount().
[AV -- add missing kstrdup()]
[AV -- put_cred() can be unconditional - fc->cred can't be NULL]
[AV -- take legacy_validate() contents into legacy_parse_monolithic()]
[AV -- merge KERNEL_MOUNT and USER_MOUNT]
[AV -- don't unlock superblock on success return from vfs_get_tree()]
[AV -- kill 'reference' argument of init_fs_context()]
Signed-off-by: David Howells <dhowells@redhat.com>
Co-developed-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

mount_subtree() creates (and soon destroys) a temporary namespace,
so that automounts could function normally.  These beasts should
never become anyone's current namespaces; they don't, but it would
be better to make prevention of that more straightforward.  And
since they don't become anyone's current namespace, we don't need
to bother with reserving procfs inums for those.

Teach alloc_mnt_ns() to skip inum allocation if told so, adjust
put_mnt_ns() accordingly, make mount_subtree() use temporary
(anon) namespace.  is_anon_ns() checks if a namespace is such.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Rather than having propagate_mnt() check doing unprivileged copies,
lock them before commit_tree().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

unused now and impossible to use safely anyway.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

* make the reference from superblock to cgroup_root counting -
do cgroup_put() in cgroup_kill_sb() whether we'd done
percpu_ref_kill() or not; matching grab is done when we allocate
a new root.  That gives the same refcounting rules for all callers
of cgroup_do_mount() - a reference to cgroup_root has been grabbed
by caller and it either is transferred to new superblock or dropped.

* have cgroup_kill_sb() treat an already killed refcount as "just
don't bother killing it, then".

* after successful cgroup_do_mount() have cgroup1_mount() recheck
if we'd raced with mount/umount from somebody else and cgroup_root
got killed.  In that case we drop the superblock and bugger off
with -ERESTARTSYS, same as if we'd found it in the list already
dying.

* don't bother with delayed initialization of refcount - it's
unreliable and not needed.  No need to prevent attempts to bump
the refcount if we find cgroup_root of another mount in progress -
sget will reuse an existing superblock just fine and if the
other sb manages to die before we get there, we'll catch
that immediately after cgroup_do_mount().

* don't bother with kernfs_pin_sb() - no need for doing that
either.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

same story as with last May fixes in sysfs (7b745a4e
"unfuck sysfs_mount()"); new_sb is left uninitialized
in case of early errors in kernfs_mount_ns() and papering
over it by treating any error from kernfs_mount_ns() as
equivalent to !new_ns ends up conflating the cases when
objects had never been transferred to a superblock with
ones when that has happened and resulting new superblock
had been dropped.  Easily fixed (same way as in sysfs
case).  Additionally, there's a superblock leak on
kernfs_node_dentry() failure *and* a dentry leak inside
kernfs_node_dentry() itself - the latter on probably
impossible errors, but the former not impossible to trigger
(as the matter of fact, injecting allocation failures
at that point *does* trigger it).

Cc: stable@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

UNAME26 is a mechanism to report Linux's version as 2.6.x, for
compatibility with old/broken software.  Due to the way it is
implemented, it would have to be updated after 5.0, to keep the
resulting versions unique.  Linus Torvalds argued:

 "Do we actually need this?

  I'd rather let it bitrot, and just let it return random versions. It
  will just start again at 2.4.60, won't it?

  Anybody who uses UNAME26 for a 5.x kernel might as well think it's
  still 4.x. The user space is so old that it can't possibly care about
  differences between 4.x and 5.x, can it?

  The only thing that matters is that it shows "2.4.<largeenough>",
  which it will do regardless"
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ARM SoC fixes from Olof Johansson:
 "A bigger batch than I anticipated this week, for two reasons:

   - Some fallout on Davinci from board file -> DTB conversion, that
     also includes a few longer-standing fixes (i.e. not recent
     regressions).

   - drivers/reset material that has been in linux-next for a while, but
     didn't get sent to us until now for a variety of reasons
     (maintainer out sick, holidays, etc). There's a functional
     dependency in there such that one platform (Altera's SoCFPGA) won't
     boot without one of the patches; instead of reverting the patch
     that got merged, I looked at this set and decided it was small
     enough that I'll pick it up anyway. If you disagree I can revisit
     with a smaller set.

  That being said, there's also a handful of the usual stuff:

   - Fix for a crash on Armada 7K/8K when the kernel touches
     PSCI-reserved memory

   - Fix for PCIe reset on Macchiatobin (Armada 8K development board,
     what this email is sent from in fact :)

   - Enable a few new-merged modules for Amlogic in arm64 defconfig

   - Error path fixes on Integrator

   - Build fix for Renesas and Qualcomm

   - Initialization fix for Renesas RZ/G2E

  .. plus a few more fixlets"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (28 commits)
  ARM: integrator: impd1: use struct_size() in devm_kzalloc()
  qcom-scm: Include <linux/err.h> header
  gpio: pl061: handle failed allocations
  ARM: dts: kirkwood: Fix polarity of GPIO fan lines
  arm64: dts: marvell: mcbin: fix PCIe reset signal
  arm64: dts: marvell: armada-ap806: reserve PSCI area
  ARM: dts: da850-lcdk: Correct the sound card name
  ARM: dts: da850-lcdk: Correct the audio codec regulators
  ARM: dts: da850-evm: Correct the sound card name
  ARM: dts: da850-evm: Correct the audio codec regulators
  ARM: davinci: omapl138-hawk: fix label names in GPIO lookup entries
  ARM: davinci: dm644x-evm: fix label names in GPIO lookup entries
  ARM: davinci: dm355-evm: fix label names in GPIO lookup entries
  ARM: davinci: da850-evm: fix label names in GPIO lookup entries
  ARM: davinci: da830-evm: fix label names in GPIO lookup entries
  arm64: defconfig: enable modules for amlogic s400 sound card
  reset: uniphier-glue: Add AHCI reset control support in glue layer
  dt-bindings: reset: uniphier: Add AHCI core reset description
  reset: uniphier-usb3: Rename to reset-uniphier-glue
  dt-bindings: reset: uniphier: Replace the expression of USB3 with generic peripherals
  ...

Pull btrfs fixes from David Sterba:

 - two regression fixes in clone/dedupe ioctls, the generic check
   callback needs to lock extents properly and wait for io to avoid
   problems with writeback and relocation

 - fix deadlock when using free space tree due to block group creation

 - a recently added check refuses a valid fileystem with seeding device,
   make that work again with a quickfix, proper solution needs more
   intrusive changes

* tag 'for-5.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: Use real device structure to verify dev extent
  Btrfs: fix deadlock when using free space tree due to block group creation
  Btrfs: fix race between reflink/dedupe and relocation
  Btrfs: fix race between cloning range ending at eof and writeback

Pull driver core fixes from Greg KH:
 "Here is one small sysfs change, and a documentation update for 5.0-rc2

  The sysfs change moves from using BUG_ON to WARN_ON, as discussed in
  an email thread on lkml while trying to track down another driver bug.
  sysfs should not be crashing and preventing people from seeing where
  they went wrong. Now it properly recovers and warns the developer.

  The documentation update removes the use of BUS_ATTR() as the kernel
  is moving away from this to use the specific BUS_ATTR_RW() and friends
  instead. There are pending patches in all of the different subsystems
  to remove the last users of this macro, but for now, don't advertise
  it should be used anymore to keep new ones from being introduced.

  Both have been in linux-next with no reported issues"

* tag 'driver-core-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Documentation: driver core: remove use of BUS_ATTR
  sysfs: convert BUG_ON to WARN_ON

Pull staging driver fixes from Greg KH:
 "Here are some small staging driver fixes for some reported issues.

  One reverts a patch that was made to the rtl8723bs driver that turned
  out to not be needed at all as it was a bug in clang. The others fix
  up some reported issues in the rtl8188eu driver and update the
  MAINTAINERS file to point to Larry for this driver so he can get the
  bug reports easier.

  All have been in linux-next with no reported issues"

* tag 'staging-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  Revert "staging: rtl8723bs: Mark ACPI table declaration as used"
  staging: rtl8188eu: Fix module loading from tasklet for WEP encryption
  staging: rtl8188eu: Fix module loading from tasklet for CCMP encryption
  MAINTAINERS: Add entry for staging driver r8188eu

Pull tty/serial fixes from Greg KH:
 "Here are 2 tty and serial fixes for 5.0-rc2 that resolve some reported
  issues.

  The first is a simple serial driver fix for a regression that showed
  up in 5.0-rc1. The second one resolves a number of reported issues
  with the recent tty locking fixes that went into 5.0-rc1. Lots of
  people have tested the second one and say it resolves their issues.

  Both have been in linux-next with no reported issues"

* tag 'tty-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: Don't hold ldisc lock in tty_reopen() if ldisc present
  serial: lantiq: Do not swap register read/writes

Pull USB fixes from Greg KH:
 "Here are some small USB driver fixes and quirk updates for 5.0-rc2.

  The majority here are some quirks for some storage devices to get them
  to work properly. There's also a fix here to resolve the reported
  issues with some audio devices that say they are UAC3 compliant, but
  really are not.

  And a fix up for the MAINTAINERS file to remove a dead url.

  All have been in linux-next with no reported issues"

* tag 'usb-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: storage: Remove outdated URL from MAINTAINERS
  USB: Add USB_QUIRK_DELAY_CTRL_MSG quirk for Corsair K70 RGB
  usbcore: Select only first configuration for non-UAC3 compliant devices
  USB: storage: add quirk for SMI SM3350
  USB: storage: don't insert sane sense for SPC3+ when bad sense specified
  usb: cdc-acm: send ZLP for Telit 3G Intel based modems

Pull cifs fixes from Steve French:
 "A set of cifs/smb3 fixes, 4 for stable, most from Pavel. His patches
  fix an important set of crediting (flow control) problems, and also
  two problems in cifs_writepages, ddressing some large i/o and also
  compounding issues"

* tag '5.0-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module version number
  CIFS: Fix error paths in writeback code
  CIFS: Move credit processing to mid callbacks for SMB3
  CIFS: Fix credits calculation for cancelled requests
  cifs: Fix potential OOB access of lock element array
  cifs: Limit memory used by lock request calls to a page
  cifs: move large array from stack to heap
  CIFS: Do not hide EINTR after sending network packets
  CIFS: Fix credit computation for compounded requests
  CIFS: Do not set credits to 1 if the server didn't grant anything
  CIFS: Fix adjustment of credits for MTU requests
  cifs: Fix a tiny potential memory leak
  cifs: Fix a debug message

Late reset controller changes for v5.0

This adds missing deassert functionality to the ARC HSDK reset driver,
fixes some indentation and grammar issues in the kernel docs, adds a
helper to count the number of resets on a device for the non-DT case
as well, adds an early reset driver for SoCFPGA and simple reset driver
support for Stratix10, and generalizes the uniphier USB3 glue layer
reset to also cover AHCI.

* tag 'reset-for-5.0-rc2' of git://git.pengutronix.de/git/pza/linux:
  reset: uniphier-glue: Add AHCI reset control support in glue layer
  dt-bindings: reset: uniphier: Add AHCI core reset description
  reset: uniphier-usb3: Rename to reset-uniphier-glue
  dt-bindings: reset: uniphier: Replace the expression of USB3 with generic peripherals
  ARM: socfpga: dts: document "altr,stratix10-rst-mgr" binding
  reset: socfpga: add an early reset driver for SoCFPGA
  reset: fix null pointer dereference on dev by dev_name
  reset: Add reset_control_get_count()
  reset: Improve reset controller kernel docs
  ARC: HSDK: improve reset driver
Signed-off-by: Olof Johansson <olof@lixom.net>

mvebu fixes for 5.0

They are all device tree fixes which also worth being in stable:

 - Reserve PSCI area on Armada 7K/8K preventing the kernel accessing
   this area and crashing while doing it.

 - Use correct PCIe reset signal on MACCHIATOBin  (Armada 8040 based)

 - Fix polarity of GPIO fan line D-Link DNS NASes(kikwood based)

* tag 'mvebu-fixes-5.0-1' of git://git.infradead.org/linux-mvebu:
  ARM: dts: kirkwood: Fix polarity of GPIO fan lines
  arm64: dts: marvell: mcbin: fix PCIe reset signal
  arm64: dts: marvell: armada-ap806: reserve PSCI area
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'integrator-fixes-armsoc' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator into fixes

Fixes for the Integrator:
- Handle failed allocations in the IM/PC bus attachment.
- Use struct_size() for allocation.

* tag 'integrator-fixes-armsoc' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator:
  ARM: integrator: impd1: use struct_size() in devm_kzalloc()
  gpio: pl061: handle failed allocations
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'amlogic-fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-amlogic into fixes

Amlogic DT fixes for v5.0-rc
- arm64: defconfig: enable modules for amlogic s400 sound card

* tag 'amlogic-fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-amlogic:
  arm64: defconfig: enable modules for amlogic s400 sound card
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'qcom-fixes-for-5.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/agross/linux into fixes

Qualcomm Driver Fixes for 5.0-rc1

* Add required includes into qcom_scm.h

* tag 'qcom-fixes-for-5.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/agross/linux:
  qcom-scm: Include <linux/err.h> header
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'davinci-fixes-for-v5.0' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci into fixes

This pull request fixes some more regressions on legacy
DaVinci board support due to GPIO driver clean-up introduced
in v4.20 kernel. These are marked for stable.

Also has fixes for some long standing Audio issues on DA850
boards.

* tag 'davinci-fixes-for-v5.0' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci:
  ARM: dts: da850-lcdk: Correct the sound card name
  ARM: dts: da850-lcdk: Correct the audio codec regulators
  ARM: dts: da850-evm: Correct the sound card name
  ARM: dts: da850-evm: Correct the audio codec regulators
  ARM: davinci: omapl138-hawk: fix label names in GPIO lookup entries
  ARM: davinci: dm644x-evm: fix label names in GPIO lookup entries
  ARM: davinci: dm355-evm: fix label names in GPIO lookup entries
  ARM: davinci: da850-evm: fix label names in GPIO lookup entries
  ARM: davinci: da830-evm: fix label names in GPIO lookup entries
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'renesas-fixes-for-v5.0' of https://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into fixes

Renesas ARM Based SoC Fixes for v5.0

Renesas SoCs:
* Fix build regressions caused by move of Kconfig symbols

RZ/G2E (r8a774c0) SoC:
* Correct initialization order of 3DG-{A,B} in SYSC driver

* tag 'renesas-fixes-for-v5.0' of https://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  soc: renesas: r8a774c0-sysc: Fix initialization order of 3DG-{A,B}
  ARM: shmobile: fix build regressions
Signed-off-by: Olof Johansson <olof@lixom.net>

Commit 49e54187 ("ata: libahci_platform: comply to PHY framework") uses
the PHY_MODE_SATA, but that enum had not yet been added. This caused a
build failure for me, with today's linux.git.

Also, there is a potentially conflicting (mis-named) PHY_MODE_SATA, hiding
in the Marvell Berlin SATA PHY driver.

Fix the build by:

    1) Renaming Marvell's defined value to a more scoped name,
       in order to avoid any potential conflicts: PHY_BERLIN_MODE_SATA.

    2) Adding the missing enum, which was going to be added anyway as part
       of [1].

[1] https://lkml.kernel.org/r/20190108163124.6409-3-miquel.raynal@bootlin.com

Fixes: 49e54187 ("ata: libahci_platform: comply to PHY framework")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Olof Johansson <olof@lixom.net>
Cc: Grzegorz Jaszczyk <jaz@semihalf.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph, with little fixes all over the map

 - Loop caching fix for offset/bs change (Jaegeuk Kim)

 - Block documentation tweaks (Jeff, Jon, Weiping, John)

 - null_blk zoned tweak (John)

 - ahch mvebu suspend/resume support. Should have gone into the merge
   window, but there was some confusion on which tree had it. (Miquel)

* tag 'for-linus-20190112' of git://git.kernel.dk/linux-block: (22 commits)
  ata: ahci: mvebu: request PHY suspend/resume for Armada 3700
  ata: ahci: mvebu: add Armada 3700 initialization needed for S2RAM
  ata: ahci: mvebu: do Armada 38x configuration only on relevant SoCs
  ata: ahci: mvebu: remove stale comment
  ata: libahci_platform: comply to PHY framework
  loop: drop caches if offset or block_size are changed
  block: fix kerneldoc comment for blk_attempt_plug_merge()
  nvme: don't initlialize ctrl->cntlid twice
  nvme: introduce NVME_QUIRK_IGNORE_DEV_SUBNQN
  nvme: pad fake subsys NQN vid and ssvid with zeros
  nvme-multipath: zero out ANA log buffer
  nvme-fabrics: unset write/poll queues for discovery controllers
  nvme-tcp: don't ask if controller is fabrics
  nvme-tcp: remove dead code
  nvme-pci: fix out of bounds access in nvme_cqe_pending
  nvme-pci: rerun irq setup on IO queue init errors
  nvme-pci: use the same attributes when freeing host_mem_desc_bufs.
  nvme-pci: fix the wrong setting of nr_maps
  block: doc: add slice_idle_us to bfq documentation
  block: clarify documentation for blk_{start|finish}_plug
  ...

Pull dma_zalloc_coherent() removal from Christoph Hellwig:
 "We've always had a weird situation around dma_zalloc_coherent. To
  safely support mapping the allocations to userspace major
  architectures like x86 and arm have always zeroed allocations from
  dma_alloc_coherent, but a couple other architectures were missing that
  zeroing either always or in corner cases.

  Then later we grew anothe dma_zalloc_coherent interface to explicitly
  request zeroing, but that just added __GFP_ZERO to the allocation
  flags, which for some allocators that didn't end up using the page
  allocator ended up being a no-op and still not zeroing the
  allocations.

  So for this merge window I fixed up all remaining architectures to
  zero the memory in dma_alloc_coherent, and made dma_zalloc_coherent a
  no-op wrapper around dma_alloc_coherent, which fixes all of the above
  issues.

  dma_zalloc_coherent is now pointless and can go away, and Luis helped
  me writing a cocchinelle script and patch series to kill it, which I
  think we should apply now just after -rc1 to finally settle these
  issue"

* tag 'remove-dma_zalloc_coherent-5.0' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: remove dma_zalloc_coherent()
  cross-tree: phase out dma_zalloc_coherent() on headers
  cross-tree: phase out dma_zalloc_coherent()

Pull KVM fixes from Radim Krčmář:
 "Minor fixes for new code, corner cases, and documentation"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  x86/kvm/nVMX: don't skip emulated instruction twice when vmptr address is not backed
  Documentation/virtual/kvm: Update URL for AMD SEV API specification
  KVM/VMX: Avoid return error when flush tlb successfully in the hv_remote_flush_tlb_with_range()
  kvm: sev: Fail KVM_SEV_INIT if already initialized
  KVM: validate userspace input in kvm_clear_dirty_log_protect()
  KVM: x86: Fix bit shifting in update_intel_pt_cfg

Pull more drm fixes from Daniel Vetter:
 "Dave sends out his pull, everybody remembers holidays are over :-)

  Since Dave's already in weekend mode and it was quite a few patches I
  figured better to apply all the pulls and forward them to you. Hence
  here 2nd part of bugfixes for -rc2.

  nouveau:
   - backlight fix
   - falcon register access fix
   - fan fix.

  i915:
   - Disable PSR for Apple panels
   - Broxton ERR_PTR error state fix
   - Kabylake VECS workaround fix
   - Unwind failure on pinning the gen7 ppgtt
   - GVT workload request allocation fix

  core:
   - Fix fb-helper to work correctly with SDL 1.2 bugs
   - Fix lockdep warning in the atomic ioctl and setproperty"

* tag 'drm-fixes-2019-01-11-1' of git://anongit.freedesktop.org/drm/drm:
  drm/nouveau/falcon: avoid touching registers if engine is off
  drm/nouveau: Don't disable polling in fallback mode
  drm/nouveau: register backlight on pascal and newer
  drm: Fix documentation generation for DP_DPCD_QUIRK_NO_PSR
  drm/i915: init per-engine WAs for all engines
  drm/i915: Unwind failure on pinning the gen7 ppgtt
  drm/i915: Skip the ERR_PTR error state
  drm/i915: Disable PSR in Apple panels
  gpu/drm: Fix lock held when returning to user space.
  drm/fb-helper: Ignore the value of fb_var_screeninfo.pixclock
  drm/fb-helper: Partially bring back workaround for bugs of SDL 1.2
  drm/i915/gvt: Fix workload request allocation before request add

A feature has been added in the libahci driver: the possibility to set
a new flag in hpriv->flags to let the core handle PHY suspend/resume
automatically. Make use of this feature to make suspend to RAM work
with SATA drives on A3700.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

A3700 comphy initialization is done in the firmware (TF-A). Looking at
the SATA PHY initialization routine, there is a comment about "vendor
specific" registers. Two registers are mentioned. They are not
initialized there in the firmware because they are AHCI related, while
the firmware at this location does only PHY configuration. The
solution to avoid doing such initialization is relying on U-Boot.

While this work at boot time, U-Boot is definitely not going to run
during a resume after suspending to RAM.

Two possible solutions were considered:
* Fixing the firmware.
* Fixing the kernel driver.

The first solution would take ages to propagate, while the second
solution is easy to implement as the driver as been a little bit
reworked to prepare for such platform configuration. Hence, this patch
adds an Armada 3700 configuration function to set these two registers
both at boot time (in the probe) and after a suspend (in the resume
path).
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

At the beginning, only Armada 38x SoCs where supported by the
ahci_mvebu.c driver. Commit 15d3ce7b ("ata: ahci_mvebu: add
support for Armada 3700 variant") introduced Armada 3700 support. As
opposed to Armada 38x SoCs, the 3700 variants do not have to configure
mbus and the regret option. This patch took care of avoiding such
configuration when not needed in the probe function, but failed to do
the same in the resume path. While doing so looks harmless by
experience, let's clean the driver logic and avoid doing this useless
configuration with Armada 3700 SoCs.

Because the logic is very similar between these two places, it has
been decided to factorize this code and put it in a "Armada 38x
configuration function". This function is part of a new
(per-compatible) platform data structure, so that the addition of such
configuration function for Armada 3700 will be eased.

Fixes: 15d3ce7b ("ata: ahci_mvebu: add support for Armada 3700 variant")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

For Armada-38x (32-bit) SoCs, PM platform support has been added since:
commit 32f9494c ("ARM: mvebu: prepare pm-board.c for the
                      introduction of Armada 38x support")
commit 3cbd6a6c ("ARM: mvebu: Add standby support")

For Armada 64-bit SoCs, like the A3700 also using this AHCI driver, PM
platform support has always existed.

There are even suspend/resume hooks in this driver since:
commit d6ecf158 ("ata: ahci_mvebu: add suspend/resume support")

Remove the stale comment at the end of this driver stating that all
the above does not exist yet.

Fixes: d6ecf158 ("ata: ahci_mvebu: add suspend/resume support")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Current implementation of the libahci does not take into account the
new PHY framework. Correct the situation by adding a call to
phy_set_mode() before phy_power_on().

PHYs should also be handled at suspend/resume time. For this, call
ahci_platform_enable/disable_phys() at suspend/resume_host() time. These
calls are guarded by a HFLAG (AHCI_HFLAG_SUSPEND_PHYS) that the user of
the libahci driver must set manually in hpriv->flags at probe time. This
is to avoid breaking users that have not been tested with this change.
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Suggested-by: Grzegorz Jaszczyk <jaz@semihalf.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull i2c fixes from Wolfram Sang:
 "I2C has one core and one driver bugfix for you"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: tegra: Fix Maximum transfer size
  i2c: dev: prevent adapter retries and timeout being set as minus value