As reported by Jann, ihold() does not in fact guarantee inode
persistence. And instead of making it so, replace the usage of inode
pointers with a per boot, machine wide, unique inode identifier.

This sequence number is global, but shared (file backed) futexes are
rare enough that this should not become a performance issue.

Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Pull vfs file system parameter updates from Al Viro:
 "Saner fs_parser.c guts and data structures. The system-wide registry
  of syntax types (string/enum/int32/oct32/.../etc.) is gone and so is
  the horror switch() in fs_parse() that would have to grow another case
  every time something got added to that system-wide registry.

  New syntax types can be added by filesystems easily now, and their
  namespace is that of functions - not of system-wide enum members. IOW,
  they can be shared or kept private and if some turn out to be widely
  useful, we can make them common library helpers, etc., without having
  to do anything whatsoever to fs_parse() itself.

  And we already get that kind of requests - the thing that finally
  pushed me into doing that was "oh, and let's add one for timeouts -
  things like 15s or 2h". If some filesystem really wants that, let them
  do it. Without somebody having to play gatekeeper for the variants
  blessed by direct support in fs_parse(), TYVM.

  Quite a bit of boilerplate is gone. And IMO the data structures make a
  lot more sense now. -200LoC, while we are at it"

* 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (25 commits)
  tmpfs: switch to use of invalfc()
  cgroup1: switch to use of errorfc() et.al.
  procfs: switch to use of invalfc()
  hugetlbfs: switch to use of invalfc()
  cramfs: switch to use of errofc() et.al.
  gfs2: switch to use of errorfc() et.al.
  fuse: switch to use errorfc() et.al.
  ceph: use errorfc() and friends instead of spelling the prefix out
  prefix-handling analogues of errorf() and friends
  turn fs_param_is_... into functions
  fs_parse: handle optional arguments sanely
  fs_parse: fold fs_parameter_desc/fs_parameter_spec
  fs_parser: remove fs_parameter_description name field
  add prefix to fs_context->log
  ceph_parse_param(), ceph_parse_mon_ips(): switch to passing fc_log
  new primitive: __fs_parse()
  switch rbd and libceph to p_log-based primitives
  struct p_log, variants of warnf() et.al. taking that one instead
  teach logfc() to handle prefices, give it saner calling conventions
  get rid of cg_invalf()
  ...

Pull misc vfs updates from Al Viro:

 - bmap series from cmaiolino

 - getting rid of convolutions in copy_mount_options() (use a couple of
   copy_from_user() instead of the __get_user() crap)

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  saner copy_mount_options()
  fibmap: Reject negative block numbers
  fibmap: Use bmap instead of ->bmap method in ioctl_fibmap
  ecryptfs: drop direct calls to ->bmap
  cachefiles: drop direct usage of ->bmap method.
  fs: Enable bmap() function to properly return errors

The former contains nothing but a pointer to an array of the latter...

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

Pull vfs recursive removal updates from Al Viro:
 "We have quite a few places where synthetic filesystems do an
  equivalent of 'rm -rf', with varying amounts of code duplication,
  wrong locking, etc. That really ought to be a library helper.

  Only debugfs (and very similar tracefs) are converted here - I have
  more conversions, but they'd never been in -next, so they'll have to
  wait"

* 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  simple_recursive_removal(): kernel-side rm -rf for ramfs-style filesystems

Pull vfs timestamp updates from Al Viro:
 "More 64bit timestamp work"

* 'imm.timestamp' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  kernfs: don't bother with timestamp truncation
  fs: Do not overload update_time
  fs: Delete timespec64_trunc()
  fs: ubifs: Eliminate timespec64_trunc() usage
  fs: ceph: Delete timespec64_trunc() usage
  fs: cifs: Delete usage of timespec64_trunc
  fs: fat: Eliminate timespec64_trunc() usage
  utimes: Clamp the timestamps in notify_change()

Pull overlayfs update from Miklos Szeredi:

 - Try to preserve holes in sparse files when copying up, thus saving
   disk space and improving performance.

 - Fix a performance regression introduced in v4.19 by preserving
   asynchronicity of IO when fowarding to underlying layers. Add VFS
   helpers to submit async iocbs.

 - Fix a regression in lseek(2) introduced in v4.19 that breaks >2G
   seeks on 32bit kernels.

 - Fix a corner case where st_ino/st_dev was not preserved across copy
   up.

 - Miscellaneous fixes and cleanups.

* tag 'ovl-update-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix lseek overflow on 32bit
  ovl: add splice file read write helper
  ovl: implement async IO routines
  vfs: add vfs_iocb_iter_[read|write] helper functions
  ovl: layer is const
  ovl: fix corner case of non-constant st_dev;st_ino
  ovl: fix corner case of conflicting lower layer uuid
  ovl: generalize the lower_fs[] array
  ovl: simplify ovl_same_sb() helper
  ovl: generalize the lower_layers[] array
  ovl: improving copy-up efficiency for big sparse file
  ovl: use ovl_inode_lock in ovl_llseek()
  ovl: use pr_fmt auto generate prefix
  ovl: fix wrong WARN_ON() in ovl_cache_update_ino()

By now, bmap() will either return the physical block number related to
the requested file offset or 0 in case of error or the requested offset
maps into a hole.
This patch makes the needed changes to enable bmap() to proper return
errors, using the return value as an error return, and now, a pointer
must be passed to bmap() to be filled with the mapped physical block.

It will change the behavior of bmap() on return:

- negative value in case of error
- zero on success or map fell into a hole

In case of a hole, the *block will be zero too

Since this is a prep patch, by now, the only error return is -EINVAL if
->bmap doesn't exist.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

At some point filemap_write_and_wait() and
filemap_write_and_wait_range() got the exact same implementation with
the exception of the range being specified in *_range()

Similar to other functions in fs.h which call *_range(..., 0,
LLONG_MAX), change filemap_write_and_wait() to be a static inline which
calls filemap_write_and_wait_range()

Link: http://lkml.kernel.org/r/20191129160713.30892-1-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull SCSI updates from James Bottomley:
 "This series is slightly unusual because it includes Arnd's compat
  ioctl tree here:

    1c46a2cf2dbd Merge tag 'block-ioctl-cleanup-5.6' into 5.6/scsi-queue

  Excluding Arnd's changes, this is mostly an update of the usual
  drivers: megaraid_sas, mpt3sas, qla2xxx, ufs, lpfc, hisi_sas.

  There are a couple of core and base updates around error propagation
  and atomicity in the attribute container base we use for the SCSI
  transport classes.

  The rest is minor changes and updates"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (149 commits)
  scsi: hisi_sas: Rename hisi_sas_cq.pci_irq_mask
  scsi: hisi_sas: Add prints for v3 hw interrupt converge and automatic affinity
  scsi: hisi_sas: Modify the file permissions of trigger_dump to write only
  scsi: hisi_sas: Replace magic number when handle channel interrupt
  scsi: hisi_sas: replace spin_lock_irqsave/spin_unlock_restore with spin_lock/spin_unlock
  scsi: hisi_sas: use threaded irq to process CQ interrupts
  scsi: ufs: Use UFS device indicated maximum LU number
  scsi: ufs: Add max_lu_supported in struct ufs_dev_info
  scsi: ufs: Delete is_init_prefetch from struct ufs_hba
  scsi: ufs: Inline two functions into their callers
  scsi: ufs: Move ufshcd_get_max_pwr_mode() to ufshcd_device_params_init()
  scsi: ufs: Split ufshcd_probe_hba() based on its called flow
  scsi: ufs: Delete struct ufs_dev_desc
  scsi: ufs: Fix ufshcd_probe_hba() reture value in case ufshcd_scsi_add_wlus() fails
  scsi: ufs-mediatek: enable low-power mode for hibern8 state
  scsi: ufs: export some functions for vendor usage
  scsi: ufs-mediatek: add dbg_register_dump implementation
  scsi: qla2xxx: Fix a NULL pointer dereference in an error path
  scsi: qla1280: Make checking for 64bit support consistent
  scsi: megaraid_sas: Update driver version to 07.713.01.00-rc1
  ...