Add a flag ([EXT4|FS]_DAX_FL) to preserve FS_XFLAG_DAX in the ext4
inode.

Set the flag to be user visible and changeable.  Set the flag to be
inherited.  Allow applications to change the flag at any time except if
it conflicts with the set of mutually exclusive flags (Currently VERITY,
ENCRYPT, JOURNAL_DATA).

Furthermore, restrict setting any of the exclusive flags if DAX is set.

While conceptually possible, we do not allow setting EXT4_DAX_FL while
at the same time clearing exclusion flags (or vice versa) for 2 reasons:

	1) The DAX flag does not take effect immediately which
	   introduces quite a bit of complexity
	2) There is no clear use case for being this flexible

Finally, on regular files, flag the inode to not be cached to facilitate
changing S_DAX on the next creation of the inode.
Signed-off-by: NIra Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-9-ira.weiny@intel.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

The jflag variable serves almost no purpose.  Remove it.
Signed-off-by: NIra Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-8-ira.weiny@intel.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

We add 'always', 'never', and 'inode' (default).  '-o dax' continues to
operate the same which is equivalent to 'always'.  This new
functionality is limited to ext4 only.

Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER and set
it and EXT4_MOUNT_DAX_ALWAYS appropriately for the mode.

We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX.

Finally, EXT4_MOUNT2_DAX_INODE is used solely to detect if the user
specified that option for printing.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NIra Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-7-ira.weiny@intel.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

To prevent complications with in memory inodes we only set S_DAX on
inode load.  FS_XFLAG_DAX can be changed at any time and S_DAX will
change after inode eviction and reload.

Add init bool to ext4_set_inode_flags() to indicate if the inode is
being newly initialized.

Assert that S_DAX is not set on an inode which is just being loaded.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NIra Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-6-ira.weiny@intel.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

S_DAX should only be enabled when the underlying block device supports
dax.

Cache the underlying support for DAX in the super block and modify
ext4_should_use_dax() to check for device support prior to the over
riding mount option.

While we are at it change the function to ext4_should_enable_dax() as
this better reflects the ask as well as matches xfs.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NIra Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-5-ira.weiny@intel.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

In prep for the new tri-state mount option which then introduces
EXT4_MOUNT_DAX_NEVER.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NIra Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-4-ira.weiny@intel.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

Verity and DAX are incompatible.  Changing the DAX mode due to a verity
flag change is wrong without a corresponding address_space_operations
update.

Make the 2 options mutually exclusive by returning an error if DAX was
set first.

(Setting DAX is already disabled if Verity is set first.)
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NIra Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-3-ira.weiny@intel.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

When preventing DAX and journaling on an inode.  Use the effective DAX
check rather than the mount option.

This will be required to support per inode DAX flags.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20200528150003.828793-2-ira.weiny@intel.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

DCACHE_DONTCACHE indicates a dentry should not be cached on final
dput().

Also add a helper function to mark DCACHE_DONTCACHE on all dentries
pointing to a specific inode when that inode is being set I_DONTCACHE.

This facilitates dropping dentry references to inodes sooner which
require eviction to swap S_DAX mode.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

DAX effective mode (S_DAX) changes requires inode eviction.

XFS has an advisory flag (XFS_IDONTCACHE) to prevent caching of the
inode if no other additional references are taken.  We lift this flag to
the VFS layer and change the behavior slightly by allowing the flag to
remain even if multiple references are taken.

This will expedite the eviction of inodes to change S_DAX.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Update the Usage section to reflect the new individual dax selection
functionality.
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

In order for users to determine if a file is currently operating in DAX
state (effective DAX).  Define a statx attribute value and set that
attribute if the effective DAX flag is set.

To go along with this we propose the following addition to the statx man
page:

STATX_ATTR_DAX

	The file is in the DAX (cpu direct access) state.  DAX state
	attempts to minimize software cache effects for both I/O and
	memory mappings of this file.  It requires a file system which
	has been configured to support DAX.

	DAX generally assumes all accesses are via cpu load / store
	instructions which can minimize overhead for small accesses, but
	may adversely affect cpu utilization for large transfers.

	File I/O is done directly to/from user-space buffers and memory
	mapped I/O may be performed with direct memory mappings that
	bypass kernel page cache.

	While the DAX property tends to result in data being transferred
	synchronously, it does not give the same guarantees of O_SYNC
	where data and the necessary metadata are transferred together.

	A DAX file may support being mapped with the MAP_SYNC flag,
	which enables a program to use CPU cache flush instructions to
	persist CPU store operations without an explicit fsync(2).  See
	mmap(2) for more information.
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Remove the check because DAX now has it's own read/write methods and
file systems which support DAX check IS_DAX() prior to IOCB_DIRECT on
their own.  Therefore, it does not matter if the file state is DAX when
the iocb flags are created.

Also remove io_is_direct() as it is just a simple flag check.
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Pull more btrfs fixes from David Sterba:
 "A few more stability fixes, minor build warning fixes and git url
  fixup:

   - fix partial loss of prealloc extent past i_size after fsync

   - fix potential deadlock due to wrong transaction handle passing via
     journal_info

   - fix gcc 4.8 struct intialization warning

   - update git URL in MAINTAINERS entry"

* tag 'for-5.7-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  MAINTAINERS: btrfs: fix git repo URL
  btrfs: fix gcc-4.8 build warning for struct initializer
  btrfs: transaction: Avoid deadlock due to bad initialization timing of fs_info::journal_info
  btrfs: fix partial loss of prealloc extent past i_size after fsync

Pull IOMMU fixes from Joerg Roedel:

 - Fix a memory leak when dev_iommu gets freed and a sub-pointer does
   not

 - Build dependency fixes for Mediatek, spapr_tce, and Intel IOMMU
   driver

 - Export iommu_group_get_for_dev() only for GPLed modules

 - Fix AMD IOMMU interrupt remapping when x2apic is enabled

 - Fix error path in the QCOM IOMMU driver probe function

* tag 'iommu-fixes-v5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/qcom: Fix local_base status check
  iommu: Properly export iommu_group_get_for_dev()
  iommu/vt-d: Use right Kconfig option name
  iommu/amd: Fix legacy interrupt remapping for x2APIC-enabled system
  iommu: spapr_tce: Disable compile testing to fix build on book3s_32 config
  iommu/mediatek: Fix MTK_IOMMU dependencies
  iommu: Fix the memory leak in dev_iommu_free()

The git repo listed for btrfs hasn't been updated in over a year.
List the current one instead.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Pull power management fixes from Rafael Wysocki:

 - prevent the intel_pstate driver from printing excessive diagnostic
   messages in some cases (Chris Wilson)

 - make the hibernation restore kernel freeze kernel threads as well as
   user space tasks (Dexuan Cui)

 - fix the ACPI device PM disagnostic messages to include the correct
   power state name (Kai-Heng Feng).

* tag 'pm-5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: ACPI: Output correct message on target power state
  PM: hibernate: Freeze kernel threads in software_resume()
  cpufreq: intel_pstate: Only mention the BIOS disabling turbo mode once

* pm-cpufreq:
  cpufreq: intel_pstate: Only mention the BIOS disabling turbo mode once

* pm-sleep:
  PM: hibernate: Freeze kernel threads in software_resume()

Pull iomap fix from Darrick Wong:
 "Hoist the check for an unrepresentable FIBMAP return value into
  ioctl_fibmap.

  The internal kernel function can handle 64-bit values (and is needed
  to fix a regression on ext4 + jbd2). It is only the userspace ioctl
  that is so old that it cannot deal"

* tag 'iomap-5.7-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  fibmap: Warn and return an error in case of block > INT_MAX

Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - fix handling of backchannel binding in BIND_CONN_TO_SESSION

  Bugfixes:
   - Fix a credential use-after-free issue in pnfs_roc()
   - Fix potential posix_acl refcnt leak in nfs3_set_acl
   - defer slow parts of rpc_free_client() to a workqueue
   - Fix an Oopsable race in __nfs_list_for_each_server()
   - Fix trace point use-after-free race
   - Regression: the RDMA client no longer responds to server disconnect
     requests
   - Fix return values of xdr_stream_encode_item_{present, absent}
   - _pnfs_return_layout() must always wait for layoutreturn completion

  Cleanups:
   - Remove unreachable error conditions"

* tag 'nfs-for-5.7-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: Fix a race in __nfs_list_for_each_server()
  NFSv4.1: fix handling of backchannel binding in BIND_CONN_TO_SESSION
  SUNRPC: defer slow parts of rpc_free_client() to a workqueue.
  NFSv4: Remove unreachable error condition due to rpc_run_task()
  SUNRPC: Remove unreachable error condition
  xprtrdma: Fix use of xdr_stream_encode_item_{present, absent}
  xprtrdma: Fix trace point use-after-free race
  xprtrdma: Restore wake-up-all to rpcrdma_cm_event_handler()
  nfs: Fix potential posix_acl refcnt leak in nfs3_set_acl
  NFS/pnfs: Fix a credential use-after-free issue in pnfs_roc()
  NFS/pnfs: Ensure that _pnfs_return_layout() waits for layoutreturn completion

Pull dmaengine fixes from Vinod Koul:
 "Core:
   - Documentation typo fixes
   - fix the channel indexes
   - dmatest: fixes for process hang and iterations

  Drivers:
   - hisilicon: build error fix without PCI_MSI
   - ti-k3: deadlock fix
   - uniphier-xdmac: fix for reg region
   - pch: fix data race
   - tegra: fix clock state"

* tag 'dmaengine-fix-5.7-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dmatest: Fix process hang when reading 'wait' parameter
  dmaengine: dmatest: Fix iteration non-stop logic
  dmaengine: tegra-apb: Ensure that clock is enabled during of DMA synchronization
  dmaengine: fix channel index enumeration
  dmaengine: mmp_tdma: Reset channel error on release
  dmaengine: mmp_tdma: Do not ignore slave config validation errors
  dmaengine: pch_dma.c: Avoid data race between probe and irq handler
  dt-bindings: dma: uniphier-xdmac: switch to single reg region
  include/linux/dmaengine: Typos fixes in API documentation
  dmaengine: xilinx_dma: Add missing check for empty list
  dmaengine: ti: k3-psil: fix deadlock on error path
  dmaengine: hisilicon: Fix build error without PCI_MSI

Pull VFIO fixes from Alex Williamson:

 - copy_*_user validity check for new vfio_dma_rw interface (Yan Zhao)

 - Fix a potential math overflow (Yan Zhao)

 - Use follow_pfn() for calculating PFNMAPs (Sean Christopherson)

* tag 'vfio-v5.7-rc4' of git://github.com/awilliam/linux-vfio:
  vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn()
  vfio: avoid possible overflow in vfio_iommu_type1_pin_pages
  vfio: checking of validity of user vaddr in vfio_dma_rw

Pull arm64 fix from Catalin Marinas:
 "Add -fasynchronous-unwind-tables to the vDSO CFLAGS"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: vdso: Add -fasynchronous-unwind-tables to cflags

Pull io_uring fixes from Jens Axboe:

 - Fix for statx not grabbing the file table, making AT_EMPTY_PATH fail

 - Cover a few cases where async poll can handle retry, eliminating the
   need for an async thread

 - fallback request busy/free fix (Bijan)

 - syzbot reported SQPOLL thread exit fix for non-preempt (Xiaoguang)

 - Fix extra put of req for sync_file_range (Pavel)

 - Always punt splice async. We'll improve this for 5.8, but wanted to
   eliminate the inode mutex lock from the non-blocking path for 5.7
   (Pavel)

* tag 'io_uring-5.7-2020-05-01' of git://git.kernel.dk/linux-block:
  io_uring: punt splice async because of inode mutex
  io_uring: check non-sync defer_list carefully
  io_uring: fix extra put in sync_file_range()
  io_uring: use cond_resched() in io_ring_ctx_wait_and_kill()
  io_uring: use proper references for fallback_req locking
  io_uring: only force async punt if poll based retry can't handle it
  io_uring: enable poll retry for any file with ->read_iter / ->write_iter
  io_uring: statx must grab the file table for valid fd

Pull block fixes from Jens Axboe:
 "A few fixes for this release:

   - NVMe pull request from Christoph, with a single fix for a double
     free in the namespace error handling.

   - Kill the bd_openers check in blk_drop_partitions(), fixing a
     regression in this merge window (Christoph)"

* tag 'block-5.7-2020-05-01' of git://git.kernel.dk/linux-block:
  block: remove the bd_openers checks in blk_drop_partitions
  nvme: prevent double free in nvme_alloc_ns() error handling

Pull i2c fixes from Wolfram Sang:
 "Three driver bugfixes, and two reverts because the original patches
  revealed underlying problems which the Tegra guys are now working on"

* 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: aspeed: Avoid i2c interrupt status clear race condition.
  i2c: amd-mp2-pci: Fix Oops in amd_mp2_pci_init() error handling
  Revert "i2c: tegra: Better handle case where CPU0 is busy for a long time"
  Revert "i2c: tegra: Synchronize DMA before termination"
  i2c: iproc: generate stop event for slave writes

Pull sound fixes from Takashi Iwai:
 "Just a collection of small fixes around this time:

   - One more try for fixing PCM OSS regression

   - HD-audio: a new quirk for Lenovo, the improved driver blacklisting,
     a lock fix in the minor error path, and a fix for the possible race
     at monitor notifiaction

   - USB-audio: a quirk ID fix, a fix for POD HD500 workaround"

* tag 'sound-5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: usb-audio: Correct a typo of NuPrime DAC-10 USB ID
  ALSA: opti9xx: shut up gcc-10 range warning
  ALSA: hda/hdmi: fix without unlocked before return
  ALSA: hda/hdmi: fix race in monitor detection during probe
  ALSA: hda/realtek - Two front mics on a Lenovo ThinkCenter
  ALSA: line6: Fix POD HD500 audio playback
  ALSA: pcm: oss: Place the plugin buffer overflow checks correctly (for 5.7)
  ALSA: pcm: oss: Place the plugin buffer overflow checks correctly
  ALSA: hda: Match both PCI ID and SSID for driver blacklist

Pull drm fixes from Dave Airlie:
 "Regular scheduled fixes for graphics. Nothing to extreme bunch of
  amdgpu fixes, i915 and qxl fixes, along with some misc ones.

  All seems to be progressing normally.

  core:
   - EDID off by one DTD fix
   - DP mst write return code fix

  dma-buf:
   - fix SET_NAME ioctl uapi
   - doc fixes

  amdgpu:
   - Fix a green screen on resume issue
   - PM fixes for SR-IOV SDMA fix for navi
   - Renoir display fixes
   - Cursor and pageflip stuttering fixes
   - Misc additional display fixes
   - (uapi) Add additional DCC tiling flags for navi1x

  i915:
   - Fix selftest refcnt leak (Xiyu)
   - Fix gem vma lock (Chris)
   - Fix gt's i915_request.timeline acquire by checking if cacheline is
     valid (Chris)
   - Fix IRQ postinistall fault masks (Matt)

  qxl:
   - use after gree fix
   - fix lost kunmap
   - release leak fix

  virtio:
   - context destruction fix"

* tag 'drm-fixes-2020-05-01' of git://anongit.freedesktop.org/drm/drm: (26 commits)
  dma-buf: fix documentation build warnings
  drm/qxl: qxl_release use after free
  drm/qxl: lost qxl_bo_kunmap_atomic_page in qxl_image_init_helper()
  drm/i915: Use proper fault mask in interrupt postinstall too
  drm/amd/display: Use cursor locking to prevent flip delays
  drm/amd/display: Update downspread percent to match spreadsheet for DCN2.1
  drm/amd/display: Defer cursor update around VUPDATE for all ASIC
  drm/amd/display: fix rn soc bb update
  drm/amd/display: check if REFCLK_CNTL register is present
  drm/amdgpu: bump version for invalidate L2 before SDMA IBs
  drm/amdgpu: invalidate L2 before SDMA IBs (v2)
  drm/amdgpu: add tiling flags from Mesa
  drm/amd/powerplay: avoid using pm_en before it is initialized revised
  Revert "drm/amd/powerplay: avoid using pm_en before it is initialized"
  drm/qxl: qxl_release leak in qxl_hw_surface_alloc()
  drm/qxl: qxl_release leak in qxl_draw_dirty_fb()
  drm/virtio: only destroy created contexts
  drm/dp_mst: Fix drm_dp_send_dpcd_write() return code
  drm/i915/gt: Check cacheline is valid before acquiring
  drm/i915/gem: Hold obj->vma.lock over for_each_ggtt_vma()
  ...

Pull SCSI fixes from James Bottomley:
 "Four minor fixes: three in drivers and one in the core.

  The core one allows an additional state change that fixes a regression
  introduced by an update to the aacraid driver in the previous merge
  window"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: target/iblock: fix WRITE SAME zeroing
  scsi: qla2xxx: check UNLOADING before posting async work
  scsi: qla2xxx: set UNLOADING before waiting for session deletion
  scsi: core: Allow the state change from SDEV_QUIESCE to SDEV_BLOCK

Nonblocking do_splice() still may wait for some time on an inode mutex.
Let's play safe and always punt it async.
Reported-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

io_req_defer() do double-checked locking. Use proper helpers for that,
i.e. list_empty_careful().
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

[   40.179474] refcount_t: underflow; use-after-free.
[   40.179499] WARNING: CPU: 6 PID: 1848 at lib/refcount.c:28 refcount_warn_saturate+0xae/0xf0
...
[   40.179612] RIP: 0010:refcount_warn_saturate+0xae/0xf0
[   40.179617] Code: 28 44 0a 01 01 e8 d7 01 c2 ff 0f 0b 5d c3 80 3d 15 44 0a 01 00 75 91 48 c7 c7 b8 f5 75 be c6 05 05 44 0a 01 01 e8 b7 01 c2 ff <0f> 0b 5d c3 80 3d f3 43 0a 01 00 0f 85 6d ff ff ff 48 c7 c7 10 f6
[   40.179619] RSP: 0018:ffffb252423ebe18 EFLAGS: 00010286
[   40.179623] RAX: 0000000000000000 RBX: ffff98d65e929400 RCX: 0000000000000000
[   40.179625] RDX: 0000000000000001 RSI: 0000000000000086 RDI: 00000000ffffffff
[   40.179627] RBP: ffffb252423ebe18 R08: 0000000000000001 R09: 000000000000055d
[   40.179629] R10: 0000000000000c8c R11: 0000000000000001 R12: 0000000000000000
[   40.179631] R13: ffff98d68c434400 R14: ffff98d6a9cbaa20 R15: ffff98d6a609ccb8
[   40.179634] FS:  0000000000000000(0000) GS:ffff98d6af580000(0000) knlGS:0000000000000000
[   40.179636] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   40.179638] CR2: 00000000033e3194 CR3: 000000006480a003 CR4: 00000000003606e0
[   40.179641] Call Trace:
[   40.179652]  io_put_req+0x36/0x40
[   40.179657]  io_free_work+0x15/0x20
[   40.179661]  io_worker_handle_work+0x2f5/0x480
[   40.179667]  io_wqe_worker+0x2a9/0x360
[   40.179674]  ? _raw_spin_unlock_irqrestore+0x24/0x40
[   40.179681]  kthread+0x12c/0x170
[   40.179685]  ? io_worker_handle_work+0x480/0x480
[   40.179690]  ? kthread_park+0x90/0x90
[   40.179695]  ret_from_fork+0x35/0x40
[   40.179702] ---[ end trace 85027405f00110aa ]---

Opcode handler must never put submission ref, but that's what
io_sync_file_range_finish() do. use io_steal_work() there.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The function qcom_iommu_device_probe() does not perform sufficient
error checking after executing devm_ioremap_resource(), which can
result in crashes if a critical error path is encountered.

Fixes: 0ae349a0 ("iommu/qcom: Add qcom_iommu")
Signed-off-by: NTang Bin <tangbin@cmss.chinamobile.com>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20200418134703.1760-1-tangbin@cmss.chinamobile.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

In commit a7ba5c3d ("drivers/iommu: Export core IOMMU API symbols to
permit modular drivers") a bunch of iommu symbols were exported, all
with _GPL markings except iommu_group_get_for_dev().  That export should
also be _GPL like the others.

Fixes: a7ba5c3d ("drivers/iommu: Export core IOMMU API symbols to permit modular drivers")
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NWill Deacon <will@kernel.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: John Garry <john.garry@huawei.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200430120120.2948448-1-gregkh@linuxfoundation.orgSigned-off-by: NJoerg Roedel <jroedel@suse.de>

The CONFIG_ prefix should be added in the code.

Fixes: 04618252 ("iommu/vt-d: Add Kconfig option to enable/disable scalable mode")
Reported-and-tested-by: NKumar, Sanjay K <sanjay.k.kumar@intel.com>
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Link: https://lore.kernel.org/r/20200501072427.14265-1-baolu.lu@linux.intel.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

Currently, system fails to boot because the legacy interrupt remapping
mode does not enable 128-bit IRTE (GA), which is required for x2APIC
support.

Fix by using AMD_IOMMU_GUEST_IR_LEGACY_GA mode when booting with
kernel option amd_iommu_intr=legacy instead. The initialization
logic will check GASup and automatically fallback to using
AMD_IOMMU_GUEST_IR_LEGACY if GA mode is not supported.

Fixes: 3928aa3f ("iommu/amd: Detect and enable guest vAPIC support")
Signed-off-by: NSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/1587562202-14183-1-git-send-email-suravee.suthikulpanit@amd.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

While working on to make io_uring sqpoll mode support syscalls that need
struct files_struct, I got cpu soft lockup in io_ring_ctx_wait_and_kill(),

    while (ctx->sqo_thread && !wq_has_sleeper(&ctx->sqo_wait))
        cpu_relax();

above loop never has an chance to exit, it's because preempt isn't enabled
in the kernel, and the context calling io_ring_ctx_wait_and_kill() and
io_sq_thread() run in the same cpu, if io_sq_thread calls a cond_resched()
yield cpu and another context enters above loop, then io_sq_thread() will
always in runqueue and never exit.

Use cond_resched() can fix this issue.

 Reported-by: syzbot+66243bb7126c410cefe6@syzkaller.appspotmail.com
Signed-off-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use ctx->fallback_req address for test_and_set_bit_lock() and
clear_bit_unlock().
Signed-off-by: NBijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We do blocking retry from our poll handler, if the file supports polled
notifications. Only mark the request as needing an async worker if we
can't poll for it.
Signed-off-by: NJens Axboe <axboe@kernel.dk>