Pull ext4 updates from Ted Ts'o:
 "Add as a feature case-insensitive directories (the casefold feature)
  using Unicode 12.1.

  Also, the usual largish number of cleanups and bug fixes"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits)
  ext4: export /sys/fs/ext4/feature/casefold if Unicode support is present
  ext4: fix ext4_show_options for file systems w/o journal
  unicode: refactor the rule for regenerating utf8data.h
  docs: ext4.rst: document case-insensitive directories
  ext4: Support case-insensitive file name lookups
  ext4: include charset encoding information in the superblock
  MAINTAINERS: add Unicode subsystem entry
  unicode: update unicode database unicode version 12.1.0
  unicode: introduce test module for normalized utf8 implementation
  unicode: implement higher level API for string handling
  unicode: reduce the size of utf8data[]
  unicode: introduce code for UTF-8 normalization
  unicode: introduce UTF-8 character database
  ext4: actually request zeroing of inode table after grow
  ext4: cond_resched in work-heavy group loops
  ext4: fix use-after-free race with debug_want_extra_isize
  ext4: avoid drop reference to iloc.bh twice
  ext4: ignore e_value_offs for xattrs with value-in-ea-inode
  ext4: protect journal inode's blocks using block_validity
  ext4: use BUG() instead of BUG_ON(1)
  ...

Pull AFS updates from David Howells:
 "A set of fix and development patches for AFS for 5.2.

  Summary:

   - Fix the AFS file locking so that sqlite can run on an AFS mount and
     also so that firefox and gnome can use a homedir that's mounted
     through AFS.

     This required emulation of fine-grained locking when the server
     will only support whole-file locks and no upgrade/downgrade. Four
     modes are provided, settable by mount parameter:

       "flock=local"   - No reference to the server

       "flock=openafs" - Fine-grained locks are local-only, whole-file
                         locks require sufficient server locks

       "flock=strict"  - All locks require sufficient server locks

       "flock=write"   - Always get an exclusive server lock

     If the volume is a read-only or backup volume, then flock=local for
     that volume.

   - Log extra information for a couple of cases where the client mucks
     up somehow: AFS vnode with undefined type and dir check failure -
     in both cases we seem to end up with unfilled data, but the issues
     happen infrequently and are difficult to reproduce at will.

   - Implement silly rename for unlink() and rename().

   - Set i_blocks so that du can get some information about usage.

   - Fix xattr handlers to return the right amount of data and to not
     overflow buffers.

   - Implement getting/setting raw AFS and YFS ACLs as xattrs"

* tag 'afs-next-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Implement YFS ACL setting
  afs: Get YFS ACLs and information through xattrs
  afs: implement acl setting
  afs: Get an AFS3 ACL as an xattr
  afs: Fix getting the afs.fid xattr
  afs: Fix the afs.cell and afs.volume xattr handlers
  afs: Calculate i_blocks based on file size
  afs: Log more information for "kAFS: AFS vnode with undefined type\n"
  afs: Provide mount-time configurable byte-range file locking emulation
  afs: Add more tracepoints
  afs: Implement sillyrename for unlink and rename
  afs: Add directory reload tracepoint
  afs: Handle lock rpc ops failing on a file that got deleted
  afs: Improve dir check failure reports
  afs: Add file locking tracepoints
  afs: Further fix file locking
  afs: Fix AFS file locking to allow fine grained locks
  afs: Calculate lock extend timer from set/extend reply reception
  afs: Split wait from afs_make_call()

Pull vfs 'struct file' related updates from Al Viro:
 "A bit more of 'this fget() would be better off as fdget()'
  whack-a-mole + a couple of ->f_count-related cleanups"

* 'work.file' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  media: switch to fdget()
  drm_syncobj: switch to fdget()
  amdgpu: switch to fdget()
  don't open-code file_count()
  fs: drop unused fput_atomic definition

Pull mount ABI updates from Al Viro:
 "The syscalls themselves, finally.

  That's not all there is to that stuff, but switching individual
  filesystems to new methods is fortunately independent from everything
  else, so e.g. NFS series can go through NFS tree, etc.

  As those conversions get done, we'll be finally able to get rid of a
  bunch of duplication in fs/super.c introduced in the beginning of the
  entire thing. I expect that to be finished in the next window..."

* 'work.mount-syscalls' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: Add a sample program for the new mount API
  vfs: syscall: Add fspick() to select a superblock for reconfiguration
  vfs: syscall: Add fsmount() to create a mount for a superblock
  vfs: syscall: Add fsconfig() for configuring and managing a context
  vfs: Implement logging through fs_context
  vfs: syscall: Add fsopen() to prepare for superblock creation
  Make anon_inodes unconditional
  teach move_mount(2) to work with OPEN_TREE_CLONE
  vfs: syscall: Add move_mount(2) to move mounts around
  vfs: syscall: Add open_tree(2) to reference or clone a mount

Pull io_uring updates from Jens Axboe:
 "Set of changes/improvements for io_uring. This contains:

   - Fix of a shadowed variable (Colin)

   - Add support for draining commands (me)

   - Add support for sync_file_range() (me)

   - Add eventfd support (me)

   - cpu_online() fix (Shenghui)

   - Removal of a redundant ->error assignment (Stefan)"

* tag 'for-5.2/io_uring-20190507' of git://git.kernel.dk/linux-block:
  io_uring: use cpu_online() to check p->sq_thread_cpu instead of cpu_possible()
  io_uring: fix shadowed variable ret return code being not checked
  req->error only used for iopoll
  io_uring: add support for eventfd notifications
  io_uring: add support for IORING_OP_SYNC_FILE_RANGE
  fs: add sync_file_range() helper
  io_uring: add support for marking commands as draining

This just pulls out the ksys_sync_file_range() code to work on a struct
file instead of an fd, so we can use it elsewhere.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

A lot of ->destroy_inode() instances end with call_rcu() of a callback
that does RCU-delayed part of freeing.  Introduce a new method for
doing just that, with saner signature.

Rules:
->destroy_inode		->free_inode
	f			g		immediate call of f(),
						RCU-delayed call of g()
	f			NULL		immediate call of f(),
						no RCU-delayed calls
	NULL			g		RCU-delayed call of g()
	NULL			NULL		RCU-delayed default freeing

IOW, NULL ->free_inode gives the same behaviour as now.

Note that NULL, NULL is equivalent to NULL, free_inode_nonrcu; we could
mandate the latter form, but that would have very little benefit beyond
making rules a bit more symmetric.  It would break backwards compatibility,
require extra boilerplate and expected semantics for (NULL, NULL) pair
would have no use whatsoever...

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

This patch implements the actual support for case-insensitive file name
lookups in ext4, based on the feature bit and the encoding stored in the
superblock.

A filesystem that has the casefold feature set is able to configure
directories with the +F (EXT4_CASEFOLD_FL) attribute, enabling lookups
to succeed in that directory in a case-insensitive fashion, i.e: match
a directory entry even if the name used by userspace is not a byte per
byte match with the disk name, but is an equivalent case-insensitive
version of the Unicode string.  This operation is called a
case-insensitive file name lookup.

The feature is configured as an inode attribute applied to directories
and inherited by its children.  This attribute can only be enabled on
empty directories for filesystems that support the encoding feature,
thus preventing collision of file names that only differ by case.

* dcache handling:

For a +F directory, Ext4 only stores the first equivalent name dentry
used in the dcache. This is done to prevent unintentional duplication of
dentries in the dcache, while also allowing the VFS code to quickly find
the right entry in the cache despite which equivalent string was used in
a previous lookup, without having to resort to ->lookup().

d_hash() of casefolded directories is implemented as the hash of the
casefolded string, such that we always have a well-known bucket for all
the equivalencies of the same string. d_compare() uses the
utf8_strncasecmp() infrastructure, which handles the comparison of
equivalent, same case, names as well.

For now, negative lookups are not inserted in the dcache, since they
would need to be invalidated anyway, because we can't trust missing file
dentries.  This is bad for performance but requires some leveraging of
the vfs layer to fix.  We can live without that for now, and so does
everyone else.

* on-disk data:

Despite using a specific version of the name as the internal
representation within the dcache, the name stored and fetched from the
disk is a byte-per-byte match with what the user requested, making this
implementation 'name-preserving'. i.e. no actual information is lost
when writing to storage.

DX is supported by modifying the hashes used in +F directories to make
them case/encoding-aware.  The new disk hashes are calculated as the
hash of the full casefolded string, instead of the string directly.
This allows us to efficiently search for file names in the htree without
requiring the user to provide an exact name.

* Dealing with invalid sequences:

By default, when a invalid UTF-8 sequence is identified, ext4 will treat
it as an opaque byte sequence, ignoring the encoding and reverting to
the old behavior for that unique file.  This means that case-insensitive
file name lookup will not work only for that file.  An optional bit can
be set in the superblock telling the filesystem code and userspace tools
to enforce the encoding.  When that optional bit is set, any attempt to
create a file name using an invalid UTF-8 sequence will fail and return
an error to userspace.

* Normalization algorithm:

The UTF-8 algorithms used to compare strings in ext4 is implemented
lives in fs/unicode, and is based on a previous version developed by
SGI.  It implements the Canonical decomposition (NFD) algorithm
described by the Unicode specification 12.1, or higher, combined with
the elimination of ignorable code points (NFDi) and full
case-folding (CF) as documented in fs/unicode/utf8_norm.c.

NFD seems to be the best normalization method for EXT4 because:

  - It has a lower cost than NFC/NFKC (which requires
    decomposing to NFD as an intermediary step)
  - It doesn't eliminate important semantic meaning like
    compatibility decompositions.

Although:

  - This implementation is not completely linguistic accurate, because
  different languages have conflicting rules, which would require the
  specialization of the filesystem to a given locale, which brings all
  sorts of problems for removable media and for users who use more than
  one language.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Add two tracepoints for monitoring AFS file locking.  Firstly, add one that
follows the operational part:

    echo 1 >/sys/kernel/debug/tracing/events/afs/afs_flock_op/enable

And add a second that more follows the event-driven part:

    echo 1 >/sys/kernel/debug/tracing/events/afs/afs_flock_ev/enable

Individual file_lock structs seen by afs are tagged with debugging IDs that
are displayed in the trace log to make it easier to see what's going on,
especially as setting the first lock always seems to involve copying the
file_lock twice.

Signed-off-by: David Howells <dhowells@redhat.com>

commit d7065da03822 ("get rid of the magic around f_count in aio") added
fput_atomic to include/linux/fs.h, motivated by its use in __aio_put_req()
in fs/aio.c.

Later, commit 3ffa3c0e3f6e ("aio: now fput() is OK from interrupt context;
get rid of manual delayed __fput()") removed the only use of fput_atomic
in __aio_put_req(), but did not remove the since then unused fput_atomic
definition in include/linux/fs.h.

We curate this now and finally remove the unused definition.

This issue was identified during a code review due to a coccinelle warning
from the atomic_as_refcounter.cocci rule pointing to the use of atomic_t
in fput_atomic.

Suggested-by: Krystian Radlak <kradlak@exida.com>
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>