Pull misc vfs updates from Al Viro:
 "Assorted stuff all over the place"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  useful constants: struct qstr for ".."
  hostfs_open(): don't open-code file_dentry()
  whack-a-mole: kill strlen_user() (again)
  autofs: should_expire() argument is guaranteed to be positive
  apparmor:match_mn() - constify devpath argument
  buffer: a small optimization in grow_buffers
  get rid of autofs_getpath()
  constify dentry argument of dentry_path()/dentry_path_raw()

Pull fuse updates from Miklos Szeredi:

 - Fix a page locking bug in write (introduced in 2.6.26)

 - Allow sgid bit to be killed in setacl()

 - Miscellaneous fixes and cleanups

* tag 'fuse-update-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  cuse: simplify refcount
  cuse: prevent clone
  virtiofs: fix userns
  virtiofs: remove useless function
  virtiofs: split requests that exceed virtqueue size
  virtiofs: fix memory leak in virtio_fs_probe()
  fuse: invalidate attrs when page writeback completes
  fuse: add a flag FUSE_SETXATTR_ACL_KILL_SGID to kill SGID
  fuse: extend FUSE_SETXATTR request
  fuse: fix matching of FUSE_DEV_IOC_CLONE command
  fuse: fix a typo
  fuse: don't zero pages twice
  fuse: fix typo for fuse_conn.max_pages comment
  fuse: fix write deadlock

Pull fileattr conversion updates from Miklos Szeredi via Al Viro:
 "This splits the handling of FS_IOC_[GS]ETFLAGS from ->ioctl() into a
  separate method.

  The interface is reasonably uniform across the filesystems that
  support it and gives nice boilerplate removal"

* 'miklos.fileattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (23 commits)
  ovl: remove unneeded ioctls
  fuse: convert to fileattr
  fuse: add internal open/release helpers
  fuse: unsigned open flags
  fuse: move ioctl to separate source file
  vfs: remove unused ioctl helpers
  ubifs: convert to fileattr
  reiserfs: convert to fileattr
  ocfs2: convert to fileattr
  nilfs2: convert to fileattr
  jfs: convert to fileattr
  hfsplus: convert to fileattr
  efivars: convert to fileattr
  xfs: convert to fileattr
  orangefs: convert to fileattr
  gfs2: convert to fileattr
  f2fs: convert to fileattr
  ext4: convert to fileattr
  ext2: convert to fileattr
  btrfs: convert to fileattr
  ...

Pull vfs inode type handling updates from Al Viro:
 "We should never change the type bits of ->i_mode or the method tables
  (->i_op and ->i_fop) of a live inode.

  Unfortunately, not all filesystems took care to prevent that"

* 'work.inode-type-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  spufs: fix bogosity in S_ISGID handling
  9p: missing chunk of "fs/9p: Don't update file type when updating file attributes"
  openpromfs: don't do unlock_new_inode() until the new inode is set up
  hostfs_mknod(): don't bother with init_special_inode()
  cifs: have cifs_fattr_to_inode() refuse to change type on live inode
  cifs: have ->mkdir() handle race with another client sanely
  do_cifs_create(): don't set ->i_mode of something we had not created
  gfs2: be careful with inode refresh
  ocfs2_inode_lock_update(): make sure we don't change the type bits of i_mode
  orangefs_inode_is_stale(): i_mode type bits do *not* form a bitmap...
  vboxsf: don't allow to change the inode type
  afs: Fix updating of i_mode due to 3rd party change
  ceph: don't allow type or device number to change on non-I_NEW inodes
  ceph: fix up error handling with snapdirs
  new helper: inode_wrong_type()

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

Put extra reference early in cuse_channel_open().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

For cloned connections cuse_channel_release() will be called more than
once, resulting in use after free.

Prevent device cloning for CUSE, which does not make sense at this point,
and highly unlikely to be used in real life.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

get_user_ns() is done twice (once in virtio_fs_get_tree() and once in
fuse_conn_init()), resulting in a reference leak.

Also looks better to use fsc->user_ns (which *should* be the
current_user_ns() at this point).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Fix the following clang warning:

fs/fuse/virtio_fs.c:130:35: warning: unused function 'vq_to_fpq'
[-Wunused-function].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

If an incoming FUSE request can't fit on the virtqueue, the request is
placed onto a workqueue so a worker can try to resubmit it later where
there will (hopefully) be space for it next time.

This is fine for requests that aren't larger than a virtqueue's maximum
capacity.  However, if a request's size exceeds the maximum capacity of the
virtqueue (even if the virtqueue is empty), it will be doomed to a life of
being placed on the workqueue, removed, discovered it won't fit, and placed
on the workqueue yet again.

Furthermore, from section 2.6.5.3.1 (Driver Requirements: Indirect
Descriptors) of the virtio spec:

  "A driver MUST NOT create a descriptor chain longer than the Queue
  Size of the device."

To fix this, limit the number of pages FUSE will use for an overall
request.  This way, each request can realistically fit on the virtqueue
when it is decomposed into a scattergather list and avoid violating section
2.6.5.3.1 of the virtio spec.

Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>