Pull NFS client bugfixes from Trond Myklebust:

 - Fix a NFSv4 state manager deadlock when returning a delegation

 - NFSv4.2 copy do not allocate memory under the lock

 - flexfiles: Use the correct stateid for IO in the tightly coupled case

* tag 'nfs-for-4.20-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  flexfiles: use per-mirror specified stateid for IO
  NFSv4.2 copy do not allocate memory under the lock
  NFSv4: Fix a NFSv4 state manager deadlock

Pull XArray updates from Matthew Wilcox:
 "We found some bugs in the DAX conversion to XArray (and one bug which
  predated the XArray conversion). There were a couple of bugs in some
  of the higher-level functions, which aren't actually being called in
  today's kernel, but surfaced as a result of converting existing radix
  tree & IDR users over to the XArray.

  Some of the other changes to how the higher-level APIs work were also
  motivated by converting various users; again, they're not in use in
  today's kernel, so changing them has a low probability of introducing
  a bug.

  Dan can still trigger a bug in the DAX code with hot-offline/online,
  and we're working on tracking that down"

* tag 'xarray-4.20-rc4' of git://git.infradead.org/users/willy/linux-dax:
  XArray tests: Add missing locking
  dax: Avoid losing wakeup in dax_lock_mapping_entry
  dax: Fix huge page faults
  dax: Fix dax_unlock_mapping_entry for PMD pages
  dax: Reinstate RCU protection of inode
  dax: Make sure the unlocking entry isn't locked
  dax: Remove optimisation from dax_lock_mapping_entry
  XArray tests: Correct some 64-bit assumptions
  XArray: Correct xa_store_range
  XArray: Fix Documentation
  XArray: Handle NULL pointers differently for allocation
  XArray: Unify xa_store and __xa_store
  XArray: Add xa_store_bh() and xa_store_irq()
  XArray: Turn xa_erase into an exported function
  XArray: Unify xa_cmpxchg and __xa_cmpxchg
  XArray: Regularise xa_reserve
  nilfs2: Use xa_erase_irq
  XArray: Export __xa_foo to non-GPL modules
  XArray: Fix xa_for_each with a single element at 0

Pull xfs fixes from Darrick Wong:
 "Dave and I have continued our work fixing corruption problems that can
  be found when running long-term burn-in exercisers on xfs. Here are
  some patches fixing most of the problems, but there will likely be
  more. :/

   - Numerous corruption fixes for copy on write

   - Numerous corruption fixes for blocksize < pagesize writes

   - Don't miscalculate AG reservations for small final AGs

   - Fix page cache truncation to work properly for reflink and extent
     shifting

   - Fix use-after-free when retrying failed inode/dquot buffer logging

   - Fix corruptions seen when using copy_file_range in directio mode"

* tag 'xfs-4.20-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: readpages doesn't zero page tail beyond EOF
  vfs: vfs_dedupe_file_range() doesn't return EOPNOTSUPP
  iomap: dio data corruption and spurious errors when pipes fill
  iomap: sub-block dio needs to zeroout beyond EOF
  iomap: FUA is wrong for DIO O_DSYNC writes into unwritten extents
  xfs: delalloc -> unwritten COW fork allocation can go wrong
  xfs: flush removing page cache in xfs_reflink_remap_prep
  xfs: extent shifting doesn't fully invalidate page cache
  xfs: finobt AG reserves don't consider last AG can be a runt
  xfs: fix transient reference count error in xfs_buf_resubmit_failed_buffers
  xfs: uncached buffer tracing needs to print bno
  xfs: make xfs_file_remap_range() static
  xfs: fix shared extent data corruption due to missing cow reservation

Pull power management fixes from Rafael Wysocki:
 "These fix two issues in the Operating Performance Points (OPP)
  framework, one cpufreq driver issue, one problem related to the tasks
  freezer and a few build-related issues in the cpupower utility.

  Specifics:

   - Fix tasks freezer deadlock in de_thread() that occurs if one of its
     sub-threads has been frozen already (Chanho Min).

   - Avoid registering a platform device by the ti-cpufreq driver on
     platforms that cannot use it (Dave Gerlach).

   - Fix a mistake in the ti-opp-supply operating performance points
     (OPP) driver that caused an incorrect reference voltage to be used
     and make it adjust the minimum voltage dynamically to avoid hangs
     or crashes in some cases (Keerthy).

   - Fix issues related to compiler flags in the cpupower utility and
     correct a linking problem in it by renaming a file with a duplicate
     name (Jiri Olsa, Konstantin Khlebnikov)"

* tag 'pm-4.20-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  exec: make de_thread() freezable
  cpufreq: ti-cpufreq: Only register platform_device when supported
  opp: ti-opp-supply: Correct the supply in _get_optimal_vdd_voltage call
  opp: ti-opp-supply: Dynamically update u_volt_min
  tools cpupower: Override CFLAGS assignments
  tools cpupower debug: Allow to use outside build flags
  tools/power/cpupower: fix compilation with STATIC=true

rfc8435 says:

  For tight coupling, ffds_stateid provides the stateid to be used by
  the client to access the file.

However current implementation replaces per-mirror provided stateid with
by open or lock stateid.

Ensure that per-mirror stateid is used by ff_layout_write_prepare_v4 and
nfs4_ff_layout_prepare_ds.

Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Rick Macklem <rmacklem@uoguelph.ca>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Bruce pointed out that we shouldn't allocate memory while holding
a lock in the nfs4_callback_offload() and handle_async_copy()
that deal with a racing CB_OFFLOAD and reply to COPY case.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

When we read the EOF page of the file via readpages, we need
to zero the region beyond EOF that we either do not read or
should not contain data so that mmap does not expose stale data to
user applications.

However, iomap_adjust_read_range() fails to detect EOF correctly,
and so fsx on 1k block size filesystems fails very quickly with
mapreads exposing data beyond EOF. There are two problems here.

Firstly, when calculating the end block of the EOF byte, we have
to round the size by one to avoid a block aligned EOF from reporting
a block too large. i.e. a size of 1024 bytes is 1 block, which in
index terms is block 0. Therefore we have to calculate the end block
from (isize - 1), not isize.

The second bug is determining if the current page spans EOF, and so
whether we need split it into two half, one for the IO, and the
other for zeroing. Unfortunately, the code that checks whether
we should split the block doesn't actually check if we span EOF, it
just checks if the read spans the /offset in the page/ that EOF
sits on. So it splits every read into two if EOF is not page
aligned, regardless of whether we are reading the EOF block or not.

Hence we need to restrict the "does the read span EOF" check to
just the page that spans EOF, not every page we read.

This patch results in correct EOF detection through readpages:

xfs_vm_readpages:     dev 259:0 ino 0x43 nr_pages 24
xfs_iomap_found:      dev 259:0 ino 0x43 size 0x66c00 offset 0x4f000 count 98304 type hole startoff 0x13c startblock 1368 blockcount 0x4
iomap_readpage_actor: orig pos 323584 pos 323584, length 4096, poff 0 plen 4096, isize 420864
xfs_iomap_found:      dev 259:0 ino 0x43 size 0x66c00 offset 0x50000 count 94208 type hole startoff 0x140 startblock 1497 blockcount 0x5c
iomap_readpage_actor: orig pos 327680 pos 327680, length 94208, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 331776 pos 331776, length 90112, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 335872 pos 335872, length 86016, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 339968 pos 339968, length 81920, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 344064 pos 344064, length 77824, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 348160 pos 348160, length 73728, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 352256 pos 352256, length 69632, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 356352 pos 356352, length 65536, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 360448 pos 360448, length 61440, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 364544 pos 364544, length 57344, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 368640 pos 368640, length 53248, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 372736 pos 372736, length 49152, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 376832 pos 376832, length 45056, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 380928 pos 380928, length 40960, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 385024 pos 385024, length 36864, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 389120 pos 389120, length 32768, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 393216 pos 393216, length 28672, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 397312 pos 397312, length 24576, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 401408 pos 401408, length 20480, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 405504 pos 405504, length 16384, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 409600 pos 409600, length 12288, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 413696 pos 413696, length 8192, poff 0 plen 4096, isize 420864
iomap_readpage_actor: orig pos 417792 pos 417792, length 4096, poff 0 plen 3072, isize 420864
iomap_readpage_actor: orig pos 420864 pos 420864, length 1024, poff 3072 plen 1024, isize 420864

As you can see, it now does full page reads until the last one which
is split correctly at the block aligned EOF, reading 3072 bytes and
zeroing the last 1024 bytes. The original version of the patch got
this right, but it got another case wrong.

The EOF detection crossing really needs to the the original length
as plen, while it starts at the end of the block, will be shortened
as up-to-date blocks are found on the page. This means "orig_pos +
plen" no longer points to the end of the page, and so will not
correctly detect EOF crossing. Hence we have to use the length
passed in to detect this partial page case:

xfs_filemap_fault:    dev 259:1 ino 0x43  write_fault 0
xfs_vm_readpage:      dev 259:1 ino 0x43 nr_pages 1
xfs_iomap_found:      dev 259:1 ino 0x43 size 0x2cc00 offset 0x2c000 count 4096 type hole startoff 0xb0 startblock 282 blockcount 0x4
iomap_readpage_actor: orig pos 180224 pos 181248, length 4096, poff 1024 plen 2048, isize 183296
xfs_iomap_found:      dev 259:1 ino 0x43 size 0x2cc00 offset 0x2cc00 count 1024 type hole startoff 0xb3 startblock 285 blockcount 0x1
iomap_readpage_actor: orig pos 183296 pos 183296, length 1024, poff 3072 plen 1024, isize 183296

Heere we see a trace where the first block on the EOF page is up to
date, hence poff = 1024 bytes. The offset into the page of EOF is
3072, so the range we want to read is 1024 - 3071, and the range we
want to zero is 3072 - 4095. You can see this is split correctly
now.

This fixes the stale data beyond EOF problem that fsx quickly
uncovers on 1k block size filesystems.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

It returns EINVAL when the operation is not supported by the
filesystem. Fix it to return EOPNOTSUPP to be consistent with
the man page and clone_file_range().

Clean up the inconsistent error return handling while I'm there.
(I know, lipstick on a pig, but every little bit helps...)

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

When doing direct IO to a pipe for do_splice_direct(), then pipe is
trivial to fill up and overflow as it can only hold 16 pages. At
this point bio_iov_iter_get_pages() then returns -EFAULT, and we
abort the IO submission process. Unfortunately, iomap_dio_rw()
propagates the error back up the stack.

The error is converted from the EFAULT to EAGAIN in
generic_file_splice_read() to tell the splice layers that the pipe
is full. do_splice_direct() completely fails to handle EAGAIN errors
(it aborts on error) and returns EAGAIN to the caller.

copy_file_write() then completely fails to handle EAGAIN as well,
and so returns EAGAIN to userspace, having failed to copy the data
it was asked to.

Avoid this whole steaming pile of fail by having iomap_dio_rw()
silently swallow EFAULT errors and so do short reads.

To make matters worse, iomap_dio_actor() has a stale data exposure
bug bio_iov_iter_get_pages() fails - it does not zero the tail block
that it may have been left uncovered by partial IO. Fix the error
handling case to drop to the sub-block zeroing rather than
immmediately returning the -EFAULT error.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

If we are doing sub-block dio that extends EOF, we need to zero
the unused tail of the block to initialise the data in it it. If we
do not zero the tail of the block, then an immediate mmap read of
the EOF block will expose stale data beyond EOF to userspace. Found
with fsx running sub-block DIO sizes vs MAPREAD/MAPWRITE operations.

Fix this by detecting if the end of the DIO write is beyond EOF
and zeroing the tail if necessary.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>