Convert the ramfs, shmem, tmpfs, devtmpfs and rootfs filesystems to the new
internal mount API as the old one will be obsoleted and removed.  This
allows greater flexibility in communication of mount parameters between
userspace, the VFS and the filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Note that tmpfs is slightly tricky as it can contain embedded commas, so it
can't be trivially split up using strsep() to break on commas in
generic_parse_monolithic().  Instead, tmpfs has to supply its own generic
parser.

However, if tmpfs changes, then devtmpfs and rootfs, which are wrappers
around tmpfs or ramfs, must change too - and thus so must ramfs, so these
had to be converted also.

[AV: rewritten]
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Hugh Dickins <hughd@google.com>
cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

This thing will eventually become our ->parse_param(), while
shmem_parse_options() - ->parse_monolithic().  At that point
shmem_parse_options() will start calling vfs_parse_fs_string(),
rather than calling shmem_parse_one() directly.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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

just use ctx->mpol (note that callers always set ctx->mpol to NULL when
calling that).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

... and copy the data from it into sbinfo in the callers.
For use by remount we need to keep track whether there'd
been options setting max_inodes, max_blocks and huge resp.
and do the sanity checks (and copying) only if such options
had been seen.  uid/gid/mode is ignored by remount and
NULL mpol is already explicitly treated as "ignore it",
so we don't need to keep track of those.

Note: theoretically, mpol_parse_string() may return NULL
not in case of error (for default policy), so the assumption
that NULL mpol means "change nothing" is incorrect.  However,
that's the mainline behaviour and any changes belong in
a separate patch.  If we go for that, we'll need to keep
track of having encountered mpol= option too.

[changes in remount logics from Hugh Dickins folded]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

... have callers use shmem_mount()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

all users should just call ramfs_mount()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Create an internal-only type matching the current devtmpfs, never
register it and have one kernel-internal mount done.  That thing
gets mounted only once, so it is free to use mount_nodev().

The "public" devtmpfs (the one we do register, and only after
the internal mount of the real thing is done) simply gets and
returns an extra reference to the internal superblock.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Convert the squashfs filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Phillip Lougher <phillip@squashfs.org.uk>
cc: squashfs-devel@lists.sourceforge.net
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Kill mount_mtd() as it has now been replaced by vfs_get_mtd_super() in the
new mount API and nothing now uses it.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Brian Norris <computersforpeace@gmail.com>
cc: Boris Brezillon <bbrezillon@kernel.org>
cc: Marek Vasut <marek.vasut@gmail.com>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Convert the jffs2 filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: linux-mtd@lists.infradead.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Convert the cramfs filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Nicolas Pitre <nico@fluxnic.net>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
cc: linux-mtd@lists.infradead.org
cc: linux-block@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Convert the romfs filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-mtd@lists.infradead.org
cc: linux-block@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Add an additional keying mode to vfs_get_super() to indicate that only a
single superblock should exist in the system, and that, if it does, further
mounts should invoke reconfiguration upon it.

This allows mount_single() to be replaced.

[Fix by Eric Biggers folded in]
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Provide a function, get_tree_mtd(), to replace mount_mtd(), using an
fs_context struct to hold the parameters.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Brian Norris <computersforpeace@gmail.com>
cc: Boris Brezillon <bbrezillon@kernel.org>
cc: Marek Vasut <marek.vasut@gmail.com>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Create a function, get_tree_bdev(), that is fs_context-aware and a
->get_tree() counterpart of mount_bdev().

It caches the block device pointer in the fs_context struct so that this
information can be passed into sget_fc()'s test and set functions.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: linux-block@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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

fs_context::user_ns is used by fuse_parse_param(), even during remount,
so it needs to be set to the existing value for reconfigure.

Reproducer:

	#include <fcntl.h>
	#include <sys/mount.h>

	int main()
	{
		char opts[128];
		int fd = open("/dev/fuse", O_RDWR);

		sprintf(opts, "fd=%d,rootmode=040000,user_id=0,group_id=0", fd);
		mkdir("mnt", 0777);
		mount("foo",  "mnt", "fuse.foo", 0, opts);
		mount("foo", "mnt", "fuse.foo", MS_REMOUNT, opts);
	}

Crash:
	BUG: kernel NULL pointer dereference, address: 0000000000000000
	#PF: supervisor read access in kernel mode
	#PF: error_code(0x0000) - not-present page
	PGD 0 P4D 0
	Oops: 0000 [#1] SMP
	CPU: 0 PID: 129 Comm: syz_make_kuid Not tainted 5.3.0-rc5-next-20190821 #3
	Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-20181126_142135-anatol 04/01/2014
	RIP: 0010:map_id_range_down+0xb/0xc0 kernel/user_namespace.c:291
	[...]
	Call Trace:
	 map_id_down kernel/user_namespace.c:312 [inline]
	 make_kuid+0xe/0x10 kernel/user_namespace.c:389
	 fuse_parse_param+0x116/0x210 fs/fuse/inode.c:523
	 vfs_parse_fs_param+0xdb/0x1b0 fs/fs_context.c:145
	 vfs_parse_fs_string+0x6a/0xa0 fs/fs_context.c:188
	 generic_parse_monolithic+0x85/0xc0 fs/fs_context.c:228
	 parse_monolithic_mount_data+0x1b/0x20 fs/fs_context.c:708
	 do_remount fs/namespace.c:2525 [inline]
	 do_mount+0x39a/0xa60 fs/namespace.c:3107
	 ksys_mount+0x7d/0xd0 fs/namespace.c:3325
	 __do_sys_mount fs/namespace.c:3339 [inline]
	 __se_sys_mount fs/namespace.c:3336 [inline]
	 __x64_sys_mount+0x20/0x30 fs/namespace.c:3336
	 do_syscall_64+0x4a/0x1a0 arch/x86/entry/common.c:290
	 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reported-by: syzbot+7d6a57304857423318a5@syzkaller.appspotmail.com
Fixes: 408cbe695350 ("vfs: Convert fuse to use the new mount API")
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull MTD fix from Richard Weinberger:
 "A single fix for MTD to correctly set the spi-nor WP pin"

* tag 'fixes-for-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: spi-nor: Fix the disabling of write protection at init

Pull btrfs fixes from David Sterba:
 "Two fixes that popped up during testing:

   - fix for sysfs-related code that adds/removes block groups, warnings
     appear during several fstests in connection with sysfs updates in
     5.3, the fix essentially replaces a workaround with scope NOFS and
     applies to 5.2-based branch too

   - add sanity check of trim range"

* tag 'for-5.3-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: trim: Check the range passed into to prevent overflow
  Btrfs: fix sysfs warning and missing raid sysfs directories

Pull x86 fixes from Thomas Gleixner:
 "A set of fixes for x86:

   - Fix the inconsistent error handling in the umwait init code

   - Rework the boot param zeroing so gcc9 stops complaining about out
     of bound memset. The resulting source code is actually more sane to
     read than the smart solution we had

   - Maintainers update so Tony gets involved when Intel models are
     added

   - Some more fallthrough fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Save fields explicitly, zero out everything else
  MAINTAINERS, x86/CPU: Tony Luck will maintain asm/intel-family.h
  x86/fpu/math-emu: Address fallthrough warnings
  x86/apic/32: Fix yet another implicit fallthrough warning
  x86/umwait: Fix error handling in umwait_init()

Pull EFI fix from Thomas Gleixner:
 "A single fix for a EFI mixed mode regression caused by recent rework
  which did not take the firmware bitwidth into account"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi-stub: Fix get_efi_config_table on mixed-mode setups

Pull SPDX fixes from Greg KH:
 "Here are four small SPDX fixes for 5.3-rc5.

  A few style fixes for some SPDX comments, added an SPDX tag for one
  file, and fix up some GPL boilerplate for another file.

  All of these have been in linux-next for a few weeks with no reported
  issues (they are comment changes only, so that's to be expected...)"

* tag 'spdx-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
  i2c: stm32: Use the correct style for SPDX License Identifier
  intel_th: Use the correct style for SPDX License Identifier
  coccinelle: api/atomic_as_refcounter: add SPDX License Identifier
  kernel/configs: Replace GPL boilerplate code with SPDX identifier

Pull char/misc driver fixes from Greg KH:
 "Here are some small char and misc driver fixes for 5.3-rc5.

  These are two different subsystems needing some fixes, the habanalabs
  driver which is has some more big endian fixes for problems found. The
  other are some small soundwire fixes, including some Kconfig
  dependencies needed to resolve reported build errors.

  All of these have been in linux-next this week with no reported
  issues"

* tag 'char-misc-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  misc: xilinx-sdfec: fix dependency and build error
  habanalabs: fix device IRQ unmasking for BE host
  habanalabs: fix endianness handling for internal QMAN submission
  habanalabs: fix completion queue handling when host is BE
  habanalabs: fix endianness handling for packets from user
  habanalabs: fix DRAM usage accounting on context tear down
  habanalabs: Avoid double free in error flow
  soundwire: fix regmap dependencies and align with other serial links
  soundwire: cadence_master: fix definitions for INTSTAT0/1
  soundwire: cadence_master: fix register definition for SLAVE_STATE

Pull staging/IIO fixes from Greg KH:
 "Here are four small staging and iio driver fixes for 5.3-rc5

  Two are for the dt3000 comedi driver for some reported problems found
  in that codebase, and two are some small iio fixes.

  All of these have been in linux-next this week with no reported
  issues"

* tag 'staging-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: comedi: dt3000: Fix rounding up of timer divisor
  staging: comedi: dt3000: Fix signed integer overflow 'divider * base'
  iio: adc: max9611: Fix temperature reading in probe
  iio: frequency: adf4371: Fix output frequency setting

Pull USB fixes from Greg KH:
 "Here are number of small USB fixes for 5.3-rc5.

  Syzbot has been on a tear recently now that it has some good USB
  debugging hooks integrated, so there's a number of fixes in here found
  by those tools for some _very_ old bugs. Also a handful of gadget
  driver fixes for reported issues, some hopefully-final dma fixes for
  host controller drivers, and some new USB serial gadget driver ids.

  All of these have been in linux-next this week with no reported issues
  (the usb-serial ones were in linux-next in its own branch, but merged
  into mine on Friday)"

* tag 'usb-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: add a hcd_uses_dma helper
  usb: don't create dma pools for HCDs with a localmem_pool
  usb: chipidea: imx: fix EPROBE_DEFER support during driver probe
  usb: host: fotg2: restart hcd after port reset
  USB: CDC: fix sanity checks in CDC union parser
  usb: cdc-acm: make sure a refcount is taken early enough
  USB: serial: option: add the BroadMobi BM818 card
  USB: serial: option: Add Motorola modem UARTs
  USB: core: Fix races in character device registration and deregistraion
  usb: gadget: mass_storage: Fix races between fsg_disable and fsg_set_alt
  usb: gadget: composite: Clear "suspended" on reset/disconnect
  usb: gadget: udc: renesas_usb3: Fix sysfs interface of "role"
  USB: serial: option: add D-Link DWM-222 device ID
  USB: serial: option: Add support for ZTE MF871A

Pull block fixes from Jens Axboe:
 "A collection of fixes that should go into this series. This contains:

   - Revert of the REQ_NOWAIT_INLINE and associated dio changes. There
     were still corner cases there, and even though I had a solution for
     it, it's too involved for this stage. (me)

   - Set of NVMe fixes (via Sagi)

   - io_uring fix for fixed buffers (Anthony)

   - io_uring defer issue fix (Jackie)

   - Regression fix for queue sync at exit time (zhengbin)

   - xen blk-back memory leak fix (Wenwen)"

* tag 'for-linus-2019-08-17' of git://git.kernel.dk/linux-block:
  io_uring: fix an issue when IOSQE_IO_LINK is inserted into defer list
  block: remove REQ_NOWAIT_INLINE
  io_uring: fix manual setup of iov_iter for fixed buffers
  xen/blkback: fix memory leaks
  blk-mq: move cancel of requeue_work to the front of blk_exit_queue
  nvme-pci: Fix async probe remove race
  nvme: fix controller removal race with scan work
  nvme-rdma: fix possible use-after-free in connect error flow
  nvme: fix a possible deadlock when passthru commands sent to a multipath device
  nvme-core: Fix extra device_put() call on error path
  nvmet-file: fix nvmet_file_flush() always returning an error
  nvmet-loop: Flush nvme_delete_wq when removing the port
  nvmet: Fix use-after-free bug when a port is removed
  nvme-multipath: revalidate nvme_ns_head gendisk in nvme_validate_ns

Pull Hyper-V fixes from Sasha Levin:

 - A few fixes for the userspace hyper-v tools from Adrian Vladu.

 - A fix for the hyper-v MAINTAINERs entry from Lan Tianyu.

 - Fix for SPDX license identifier in the userspace tools from Nishad
   Kamdar.

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  MAINTAINERS: Fix Hyperv vIOMMU driver file name
  tools: hv: Use the correct style for SPDX License Identifier
  tools: hv: fix typos in toolchain
  tools: hv: fix KVP and VSS daemons exit code
  tools: hv: fixed Python pep8/flake8 warnings for lsvmbus

The Hyperv vIOMMU file name should be "hyperv-iommu.c" rather
than "hyperv_iommu.c". This patch is to fix it.
Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

This patch corrects the SPDX License Identifier style
in the trace header file related to Microsoft Hyper-V
client drivers.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used)

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Fix typos in the HyperV toolchain.
Signed-off-by: Adrian Vladu <avladu@cloudbasesolutions.com>

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Alessandro Pilotti <apilotti@cloudbasesolutions.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

HyperV KVP and VSS daemons should exit with 0 when the '--help'
or '-h' flags are used.
Signed-off-by: Adrian Vladu <avladu@cloudbasesolutions.com>

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Alessandro Pilotti <apilotti@cloudbasesolutions.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Fixed pep8/flake8 python style code for lsvmbus tool.

The TAB indentation was on purpose ignored (pep8 rule W191) to make
sure the code is complying with the Linux code guideline.
The following command doe not show any warnings now:
pep8 --ignore=W191 lsvmbus
flake8 --ignore=W191 lsvmbus
Signed-off-by: Adrian Vladu <avladu@cloudbasesolutions.com>

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Alessandro Pilotti <apilotti@cloudbasesolutions.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Pull i2c fixes from Wolfram Sang:
 "I2C has one revert because of a regression, two fixes for tiny race
  windows (which we were not able to trigger), a MAINTAINERS addition,
  and a SPDX fix"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: stm32: Use the correct style for SPDX License Identifier
  i2c: emev2: avoid race when unregistering slave client
  i2c: rcar: avoid race when unregistering slave client
  MAINTAINERS: i2c-imx: take over maintainership
  Revert "i2c: imx: improve the error handling in i2c_imx_dma_request()"

Pull RISC-V fixes from Paul Walmsley:

 - Two patches to fix significant bugs in floating point register
   context handling

 - A minor fix in RISC-V flush_tlb_page(), to supply a valid end address
   to flush_tlb_range()

 - Two minor defconfig additions: to build the virtio hwrng driver by
   default (for QEMU targets), and to partially synchronize the 32-bit
   defconfig with the 64-bit defconfig

* tag 'riscv/for-v5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Make __fstate_clean() work correctly.
  riscv: Correct the initialized flow of FP register
  riscv: defconfig: Update the defconfig
  riscv: rv32_defconfig: Update the defconfig
  riscv: fix flush_tlb_range() end address for flush_tlb_page()

Merge tag 'usb-serial-5.3-rc5' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-linus

Johan writes:

USB-serial fixes for 5.3-rc5

Here are some new modem device ids.

All have been in linux-next with no reported issues.
Signed-off-by: Johan Hovold <johan@kernel.org>

* tag 'usb-serial-5.3-rc5' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial:
  USB: serial: option: add the BroadMobi BM818 card
  USB: serial: option: Add Motorola modem UARTs
  USB: serial: option: add D-Link DWM-222 device ID
  USB: serial: option: Add support for ZTE MF871A

Pull Xtensa fix from Max Filippov:
 "Add missing isync into cpu_reset to make sure ITLB changes are
  effective"

* tag 'xtensa-20190816' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: add missing isync to the cpu_reset TLB code

Pull arm64 fixes from Catalin Marinas:

 - Don't taint the kernel if CPUs have different sets of page sizes
   supported (other than the one in use).

 - Issue I-cache maintenance for module ftrace trampoline.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: ftrace: Ensure module ftrace trampoline is coherent with I-side
  arm64: cpufeature: Don't treat granule sizes as strict

The initial support for dynamic ftrace trampolines in modules made use
of an indirect branch which loaded its target from the beginning of
a special section (e71a4e1b ("arm64: ftrace: add support for far
branches to dynamic ftrace")). Since no instructions were being patched,
no cache maintenance was needed. However, later in be0f272b ("arm64:
ftrace: emit ftrace-mod.o contents through code") this code was reworked
to output the trampoline instructions directly into the PLT entry but,
unfortunately, the necessary cache maintenance was overlooked.

Add a call to __flush_icache_range() after writing the new trampoline
instructions but before patching in the branch to the trampoline.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: James Morse <james.morse@arm.com>
Cc: <stable@vger.kernel.org>
Fixes: be0f272b ("arm64: ftrace: emit ftrace-mod.o contents through code")
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>