Merge tag 'fuse-update-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:
 "The most interesting part of this update is user namespace support,
  mostly done by Eric Biederman. This enables safe unprivileged fuse
  mounts within a user namespace.

  There are also a couple of fixes for bugs found by syzbot and
  miscellaneous fixes and cleanups"

* tag 'fuse-update-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: don't keep dead fuse_conn at fuse_fill_super().
  fuse: fix control dir setup and teardown
  fuse: fix congested state leak on aborted connections
  fuse: Allow fully unprivileged mounts
  fuse: Ensure posix acls are translated outside of init_user_ns
  fuse: add writeback documentation
  fuse: honor AT_STATX_FORCE_SYNC
  fuse: honor AT_STATX_DONT_SYNC
  fuse: Restrict allow_other to the superblock's namespace or a descendant
  fuse: Support fuse filesystems outside of init_user_ns
  fuse: Fail all requests with invalid uids or gids
  fuse: Remove the buggy retranslation of pids in fuse_dev_do_read
  fuse: return -ECONNABORTED on /dev/fuse read after abort
  fuse: atomic_o_trunc should truncate pagecache

include/uapi/linux/fuse.h

@@ -113,6 +113,9 @@
  *  7.26
  *  - add FUSE_HANDLE_KILLPRIV
  *  - add FUSE_POSIX_ACL
+ *
+ *  7.27
+ *  - add FUSE_ABORT_ERROR
  */
 
 #ifndef _LINUX_FUSE_H
@@ -148,7 +151,7 @@
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 26
+#define FUSE_KERNEL_MINOR_VERSION 27
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -245,6 +248,7 @@ struct fuse_file_lock {
  * FUSE_PARALLEL_DIROPS: allow parallel lookups and readdir
  * FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on write/chown/trunc
  * FUSE_POSIX_ACL: filesystem supports posix acls
+ * FUSE_ABORT_ERROR: reading the device after abort returns ECONNABORTED
  */
 #define FUSE_ASYNC_READ		(1 << 0)
 #define FUSE_POSIX_LOCKS	(1 << 1)
@@ -267,6 +271,7 @@ struct fuse_file_lock {
 #define FUSE_PARALLEL_DIROPS    (1 << 18)
 #define FUSE_HANDLE_KILLPRIV	(1 << 19)
 #define FUSE_POSIX_ACL		(1 << 20)
+#define FUSE_ABORT_ERROR	(1 << 21)
 
 /**
  * CUSE INIT request/reply flags