Current rsnd driver setups BRGCKR/BRRA/BRRB when .probe timing.
But it breaks sound after Suspend/Resume. These should be setups
every start timing.
This patch is tested on R-Car Gen3 Salvator-X board
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Gaku Inami <gaku.inami.xw@bp.renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current rsnd driver enables ADG clock when .probe timing,
but it breaks sound after Suspend/Resume. These should be setups
every suspend/resume timing too.
This patch is tested on R-Car Gen3 Salvator-X board
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Gaku Inami <gaku.inami.xw@bp.renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

ssi->usrcnt will be updated on snd_soc_dai_ops::trigger,
but snd_pcm_ops::hw_params will be called *before* it.
Thus, ssi->usrcnt is still 0 when 1st call.
rsnd_ssi_hw_params() needs to check its called count, this means
trigger should be if (ssi->usrcnt) instead of if (ssi->usrcnt > 1).
Reported-by: Nguyen Viet Dung <nv-dung@jinso.co.jp>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

SSIU was controlled by SSI before, but
commit c7f69ab5("ASoC: rsnd: use mod base common method on SSIU")
separated it into ssiu.c

But, it didn't care about rsnd_get_dalign() for judging SSI_BUSIF_DALIGN
register value which changes the stream data order.
This function will be called from cmd/src/ssiu now, but current code
still cares ssi, not ssiu.
This patch fix it up
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

IOMMU needs DMA mapping function to use it. One solution is that
we can use DMA mapped dev on snd_pcm_lib_preallocate_pages_for_all()
for SNDRV_DMA_TYPE_DEV. But pcm_new and dma map timing are mismatched.
Thus, this patch uses SNDRV_DMA_TYPE_CONTINUOUS for pcm_new,
and use dma_sync_single_for_xxx() for each transfer.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current Renesas Sound driver requests DMA channel when .probe timing,
and release it when .remove timing. And use DMA on .start/.stop
But, Audio DMAC power ON was handled when request timing (= .probe),
and power OFF was when release timing (= .remove).
This means Audio DMAC power is always ON during driver was enabled.
The best choice to solve this issue is that DMAEngine side handle
this. But current DMAEngine API design can't solve atmic/non-atmic
context issue for power ON/OFF. So next better choice is sound
driver request/release DMA channel each time. This patch do it
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current register name of "SSICKR" was came from R-Car Gen1
which is very old style. It is called as "BRGCKR" on R-Car Gen2/Gen3.
Let's rename it
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current SRC (= Sampling Rate Converter) is supporting
SYNC mode and ASYNC mode. Current src.c cares SRC if FIN != FOUT.
Here, SYNC mode will be used for tweak, so it will be used
even FIN = FOUT. This patch enables SRC sync in such situation
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Tested-by: Yuichi Takagi <yuichi.takagi.uh@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Renesas sound SSIU has SSI_SYS_STATUS register whick will
be changed if over/under run was occurred.
Current rsnd driver is handling over/under run error on SSI/SRC,
but doesn't on SSIU.
HW guys can't guarantee correct behavior if it already had error bit
on status register when it start.
Thus, it should be cleared every start timing. This patch do it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

SCU_SYS_STATUSx is the register that writing 1 initializes the bit,
and writing 0 is ignored. So, it should use rsnd_mod_write()
instead of rsnd_mod_bset(), otherwise all bit will be cleared.
Thanks Shimoda-san
Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

R-Car Gen1 didn't have SSIU IP, and it was part of SRU.
In Gen2, SSIU was created and it has original register.
Let's cleanup rsnd_reg for SSIU, because this driver
doesn't support Gen1 SRU any more.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Gen1 support had been removed. "Gen2 only" comment is
no longer needed.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current Renesas sound driver is completely depends on CONFIG_OF
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current Renesas Sound driver requests DMA channel when .probe timing,
and release it when .remove timing. And use DMA on .start/.stop
But, Audio DMAC power ON was handled when request timing (= .probe),
and power OFF was when release timing (= .remove).
This means Audio DMAC power is always ON during driver was enabled.
To fixup this issue, it should request/release DMA channel on each
playback/recorde timing.
But, DMA channel request/release function uses mutex lock inside.
This means it will breaks current spinlock's interrupt protect.
To solve this issue, DMA channel request/release function needs to
be called from non-spinlock area. This patch adds its callback.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current rsnd_dmaen_start() is calling of_node_put() for np,
but it is not needed if it goes through this loop.
This patch tidyup it
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

DMA mod is now connected to stream via rsnd_dai_connect().
This means DMA mod can use .remove for its clearance.
rsnd_dma_detach() is no longer needed.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

SSI will use DMA mode, and migh be fallback to PIO mode.
Using devm_request_irq() makes its operation more complex when
it fallbacks to PIO mode.
Let's use manual request_irq()/free_irq()
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current Renesas Sound driver is based on DeviceTree, and no one is
using this driver from non DT. Non-DT support is no longer needed.
Let's remove it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Now, we have for_each_rsnd_mod(), let's use it
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current rsnd driver is using too complex macro for for-loop of each mod.
rsnd_dai_call() is especially defined as very complex macro.
It is easier to read just a little bit by using for_each_rsnd_mod_xxx()
and new rsnd_status_update()
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current rsnd driver is using too complex macro for for-loop of each mod.
In order to simplify this issue, this patch adds new rsnd_mod_next()
which is non-macro.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

commit 1a5658c2 ("ASoC: rsnd: count .probe/.remove for
rsnd_mod_call()") solved multi-resource-free issue, by putting
.probe/.remove under count control. But,it breaks sound mixing case
(if it was used under DPCM). In such case, it uses MIXn/DVCn/SSIn,
and these should be always probed.
This patch reverted above patch, and solved the same issue by
modifing _rsnd_kctrl_remove() function.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Pull befs fixes from Luis de Bethencourt:
 "I recently took maintainership of the befs file system [0]. This is
  the first time I send you a git pull request, so please let me know if
  all the below is OK.

  Salah Triki and myself have been cleaning the code and fixing a few
  small bugs.

  Sorry I couldn't send this sooner in the merge window, I was waiting
  to have my GPG key signed by kernel members at ELCE in Berlin a few
  days ago."

[0] https://lkml.org/lkml/2016/7/27/502

* tag 'befs-v4.9-rc1' of git://github.com/luisbg/linux-befs: (39 commits)
  befs: befs: fix style issues in datastream.c
  befs: improve documentation in datastream.c
  befs: fix typos in datastream.c
  befs: fix typos in btree.c
  befs: fix style issues in super.c
  befs: fix comment style
  befs: add check for ag_shift in superblock
  befs: dump inode_size superblock information
  befs: remove unnecessary initialization
  befs: fix typo in befs_sb_info
  befs: add flags field to validate superblock state
  befs: fix typo in befs_find_key
  befs: remove unused BEFS_BT_PARMATCH
  fs: befs: remove ret variable
  fs: befs: remove in vain variable assignment
  fs: befs: remove unnecessary *befs_sb variable
  fs: befs: remove useless initialization to zero
  fs: befs: remove in vain variable assignment
  fs: befs: Insert NULL inode to dentry
  fs: befs: Remove useless calls to brelse in befs_find_brun_dblindirect
  ...

Pull gcc plugins update from Kees Cook:
 "This adds a new gcc plugin named "latent_entropy". It is designed to
  extract as much possible uncertainty from a running system at boot
  time as possible, hoping to capitalize on any possible variation in
  CPU operation (due to runtime data differences, hardware differences,
  SMP ordering, thermal timing variation, cache behavior, etc).

  At the very least, this plugin is a much more comprehensive example
  for how to manipulate kernel code using the gcc plugin internals"

* tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  latent_entropy: Mark functions with __latent_entropy
  gcc-plugins: Add latent_entropy plugin

Pull MIPS updates from Ralf Baechle:
 "This is the main MIPS pull request for 4.9:

  MIPS core arch code:
   - traps: 64bit kernels should read CP0_EBase 64bit
   - traps: Convert ebase to KSEG0
   - c-r4k: Drop bc_wback_inv() from icache flush
   - c-r4k: Split user/kernel flush_icache_range()
   - cacheflush: Use __flush_icache_user_range()
   - uprobes: Flush icache via kernel address
   - KVM: Use __local_flush_icache_user_range()
   - c-r4k: Fix flush_icache_range() for EVA
   - Fix -mabi=64 build of vdso.lds
   - VDSO: Drop duplicated -I*/-E* aflags
   - tracing: move insn_has_delay_slot to a shared header
   - tracing: disable uprobe/kprobe on compact branch instructions
   - ptrace: Fix regs_return_value for kernel context
   - Squash lines for simple wrapper functions
   - Move identification of VP(E) into proc.c from smp-mt.c
   - Add definitions of SYNC barrierstype values
   - traps: Ensure full EBase is written
   - tlb-r4k: If there are wired entries, don't use TLBINVF
   - Sanitise coherentio semantics
   - dma-default: Don't check hw_coherentio if device is non-coherent
   - Support per-device DMA coherence
   - Adjust MIPS64 CAC_BASE to reflect Config.K0
   - Support generating Flattened Image Trees (.itb)
   - generic: Introduce generic DT-based board support
   - generic: Convert SEAD-3 to a generic board
   - Enable hardened usercopy
   - Don't specify STACKPROTECTOR in defconfigs

  Octeon:
   - Delete dead code and files across the platform.
   - Change to use all memory into use by default.
   - Rename upper case variables in setup code to lowercase.
   - Delete legacy hack for broken bootloaders.
   - Leave maintaining the link state to the actual ethernet/PHY drivers.
   - Add DTS for D-Link DSR-500N.
   - Fix PCI interrupt routing on D-Link DSR-500N.

  Pistachio:
   - Remove ANDROID_TIMED_OUTPUT from defconfig

  TX39xx:
   - Move GPIO setup from .mem_setup() to .arch_init()
   - Convert to Common Clock Framework

  TX49xx:
   - Move GPIO setup from .mem_setup() to .arch_init()
   - Convert to Common Clock Framework

  txx9wdt:
   - Add missing clock (un)prepare calls for CCF

  BMIPS:
   - Add PW, GPIO SDHCI and NAND device node names
   - Support APPENDED_DTB
   - Add missing bcm97435svmb to DT_NONE
   - Rename bcm96358nb4ser to bcm6358-neufbox4-sercom
   - Add DT examples for BCM63268, BCM3368 and BCM6362
   - Add support for BCM3368 and BCM6362

  PCI
   - Reduce stack frame usage
   - Use struct list_head lists
   - Support for CONFIG_PCI_DOMAINS_GENERIC
   - Make pcibios_set_cache_line_size an initcall
   - Inline pcibios_assign_all_busses
   - Split pci.c into pci.c & pci-legacy.c
   - Introduce CONFIG_PCI_DRIVERS_LEGACY
   - Support generic drivers

  CPC
   - Convert bare 'unsigned' to 'unsigned int'
   - Avoid lock when MIPS CM >= 3 is present

  GIC:
   - Delete unused file smp-gic.c

  mt7620:
   - Delete unnecessary assignment for the field "owner" from PCI

  BCM63xx:
   - Let clk_disable() return immediately if clk is NULL

  pm-cps:
   - Change FSB workaround to CPU blacklist
   - Update comments on barrier instructions
   - Use MIPS standard lightweight ordering barrier
   - Use MIPS standard completion barrier
   - Remove selection of sync types
   - Add MIPSr6 CPU support
   - Support CM3 changes to Coherence Enable Register

  SMP:
   - Wrap call to mips_cpc_lock_other in mips_cm_lock_other
   - Introduce mechanism for freeing and allocating IPIs

  cpuidle:
   - cpuidle-cps: Enable use with MIPSr6 CPUs.

  SEAD3:
   - Rewrite to use DT and generic kernel feature.

  USB:
   - host: ehci-sead3: Remove SEAD-3 EHCI code

  FBDEV:
   - cobalt_lcdfb: Drop SEAD3 support

  dt-bindings:
   -  Document a binding for simple ASCII LCDs

  auxdisplay:
   - img-ascii-lcd: driver for simple ASCII LCD displays

  irqchip i8259:
   - i8259: Add domain before mapping parent irq
   - i8259: Allow platforms to override poll function
   - i8259: Remove unused i8259A_irq_pending

  Malta:
   - Rewrite to use DT

  of/platform:
   - Probe "isa" busses by default

  CM:
   - Print CM error reports upon bus errors

  Module:
   - Migrate exception table users off module.h and onto extable.h
   - Make various drivers explicitly non-modular:
   - Audit and remove any unnecessary uses of module.h

  mailmap:
   - Canonicalize to Qais' current email address.

  Documentation:
   - MIPS supports HAVE_REGS_AND_STACK_ACCESS_API

  Loongson1C:
   - Add CPU support for Loongson1C
   - Add board support
   - Add defconfig
   - Add RTC support for Loongson1C board

  All this except one Documentation fix has sat in linux-next and has
  survived Imagination's automated build test system"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (127 commits)
  Documentation: MIPS supports HAVE_REGS_AND_STACK_ACCESS_API
  MIPS: ptrace: Fix regs_return_value for kernel context
  MIPS: VDSO: Drop duplicated -I*/-E* aflags
  MIPS: Fix -mabi=64 build of vdso.lds
  MIPS: Enable hardened usercopy
  MIPS: generic: Convert SEAD-3 to a generic board
  MIPS: generic: Introduce generic DT-based board support
  MIPS: Support generating Flattened Image Trees (.itb)
  MIPS: Adjust MIPS64 CAC_BASE to reflect Config.K0
  MIPS: Print CM error reports upon bus errors
  MIPS: Support per-device DMA coherence
  MIPS: dma-default: Don't check hw_coherentio if device is non-coherent
  MIPS: Sanitise coherentio semantics
  MIPS: PCI: Support generic drivers
  MIPS: PCI: Introduce CONFIG_PCI_DRIVERS_LEGACY
  MIPS: PCI: Split pci.c into pci.c & pci-legacy.c
  MIPS: PCI: Inline pcibios_assign_all_busses
  MIPS: PCI: Make pcibios_set_cache_line_size an initcall
  MIPS: PCI: Support for CONFIG_PCI_DOMAINS_GENERIC
  MIPS: PCI: Use struct list_head lists
  ...

Pull sound fixes from Takashi Iwai:
 "Just a few trivial small fixes"

* tag 'sound-fix-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: line6: fix a crash in line6_hwdep_write()
  ALSA: seq: fix passing wrong pointer in function call of compatibility layer
  ALSA: hda - Fix a failure of micmute led when having multi adcs
  ALSA: line6: Fix POD X3 Live audio input

Pull more misc uaccess and vfs updates from Al Viro:
 "The rest of the stuff from -next (more uaccess work) + assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  score: traps: Add missing include file to fix build error
  fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths
  fs/super.c: fix race between freeze_super() and thaw_super()
  overlayfs: Fix setting IOP_XATTR flag
  iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector()
  blackfin: no access_ok() for __copy_{to,from}_user()
  arm64: don't zero in __copy_from_user{,_inatomic}
  arm: don't zero in __copy_from_user_inatomic()/__copy_from_user()
  arc: don't leak bits of kernel stack into coredump
  alpha: get rid of tail-zeroing in __copy_user()

Pull cifs fixes from Steve French:
 "Including:

   - nine bug fixes for stable. Some of these we found at the recent two
     weeks of SMB3 test events/plugfests.

   - significant improvements in reconnection (e.g. if server or network
     crashes) especially when mounted with "persistenthandles" or to
     server which advertises Continuous Availability on the share.

   - a new mount option "idsfromsid" which improves POSIX compatibility
     in some cases (when winbind not configured e.g.) by better (and
     faster) fetching uid/gid from acl (when "cifsacl" mount option is
     enabled). NB: we are almost complete work on "cifsacl" (querying
     mode/uid/gid from ACL) for SMB3, but SMB3 support for cifsacl is
     not included in this set.

   - improved handling for SMB3 "credits" (even if server is buggy)

  Still working on two sets of changes:

   - cifsacl enablement for SMB3

   - cleanup of RFC1001 length calculation (so we can handle encryption
     and multichannel and RDMA)

  And a couple of new bugs were reported recently (unrelated to above)
  so will probably have another merge request next week"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6: (21 commits)
  CIFS: Retrieve uid and gid from special sid if enabled
  CIFS: Add new mount option to set owner uid and gid from special sids in acl
  CIFS: Reset read oplock to NONE if we have mandatory locks after reopen
  CIFS: Fix persistent handles re-opening on reconnect
  SMB2: Separate RawNTLMSSP authentication from SMB2_sess_setup
  SMB2: Separate Kerberos authentication from SMB2_sess_setup
  Expose cifs module parameters in sysfs
  Cleanup missing frees on some ioctls
  Enable previous version support
  Do not send SMB3 SET_INFO request if nothing is changing
  SMB3: Add mount parameter to allow user to override max credits
  fs/cifs: reopen persistent handles on reconnect
  Clarify locking of cifs file and tcon structures and make more granular
  Fix regression which breaks DFS mounting
  fs/cifs: keep guid when assigning fid to fileinfo
  SMB3: GUIDs should be constructed as random but valid uuids
  Set previous session id correctly on SMB3 reconnect
  cifs: Limit the overall credit acquired
  Display number of credits available
  Add way to query creation time of file via cifs xattr
  ...

Pull btrfs fixes from Chris Mason:
 "Some fixes from Omar and Dave Sterba for our new free space tree.

  This isn't heavily used yet, but as we move toward making it the new
  default we wanted to nail down an endian bug"

* 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: tests: uninline member definitions in free_space_extent
  btrfs: tests: constify free space extent specs
  Btrfs: expand free space tree sanity tests to catch endianness bug
  Btrfs: fix extent buffer bitmap tests on big-endian systems
  Btrfs: catch invalid free space trees
  Btrfs: fix mount -o clear_cache,space_cache=v2
  Btrfs: fix free space tree bitmaps on big-endian systems

score images fail to build as follows.

arch/score/kernel/traps.c: In function 'show_stack':
arch/score/kernel/traps.c:55:3: error:
	implicit declaration of function '__get_user'

__get_user() is declared in asm/uaccess.h, which was previously included
through asm/module.h.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 88dd4a74 ("score: separate extable.h, switch module.h to it")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

sb_wait_write()->percpu_rwsem_release() fools lockdep to avoid the
false-positives. Now that xfs was fixed by Dave's commit dbad7c99
("xfs: stop holding ILOCK over filldir callbacks") we can remove it and
change freeze_super() and thaw_super() to run with s_writers.rw_sem locks
held; we add two trivial helpers for that, lockdep_sb_freeze_release()
and lockdep_sb_freeze_acquire().

xfstests-dev/check `grep -il freeze tests/*/???` does not trigger any
warning from lockdep.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull overlayfs updates from Miklos Szeredi:
 "This update contains fixes to the "use mounter's permission to access
  underlying layers" area, and miscellaneous other fixes and cleanups.

  No new features this time"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: use vfs_get_link()
  vfs: add vfs_get_link() helper
  ovl: use generic_readlink
  ovl: explain error values when removing acl from workdir
  ovl: Fix info leak in ovl_lookup_temp()
  ovl: during copy up, switch to mounter's creds early
  ovl: lookup: do getxattr with mounter's permission
  ovl: copy_up_xattr(): use strnlen

Change thaw_super() to check frozen != SB_FREEZE_COMPLETE rather than
frozen == SB_UNFROZEN, otherwise it can race with freeze_super() which
drops sb->s_umount after SB_FREEZE_WRITE to preserve the lock ordering.

In this case thaw_super() will wrongly call s_op->unfreeze_fs() before
it was actually frozen, and call sb_freeze_unlock() which leads to the
unbalanced percpu_up_write(). Unfortunately lockdep can't detect this,
so this triggers misc BUG_ON()'s in kernel/rcu/sync.c.
Reported-and-tested-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

ovl_fill_super calls ovl_new_inode to create a root inode for the new
superblock before initializing sb->s_xattr.  This wrongly causes
IOP_XATTR to be cleared in i_opflags of the new inode, causing SELinux
to log the following message:

  SELinux: (dev overlay, type overlay) has no xattr support

Fix this by initializing sb->s_xattr and similar fields before calling
ovl_new_inode.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Both import_iovec() and rw_copy_check_uvector() take an array
(typically small and on-stack) which is used to hold an iovec array copy
from userspace. This is to avoid an expensive memory allocation in the
fast path (i.e. few iovec elements).

The caller may have to check whether these functions actually used
the provided buffer or allocated a new one -- but this differs between
the too. Let's just add a kernel doc to clarify what the semantics are
for each function.
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>