Merge tag 'for-linus-4.12-ofs-1' of git://git.kernel.org/pub/scm/linu…

…x/kernel/git/hubcap/linux

Pull orangefs updates from Mike Marshall:
 "Orangefs cleanups, fixes and statx support.

  Some cleanups:

   - remove unused get_fsid_from_ino
   - fix bounds check for listxattr
   - clean up oversize xattr validation
   - do not set getattr_time on orangefs_lookup
   - return from orangefs_devreq_read quickly if possible
   - do not wait for timeout if umounting
   - handle zero size write in debugfs

  Bug fixes:

   - do not check possibly stale size on truncate
   - ensure the userspace component is unmounted if mount fails
   - total reimplementation of dir.c

  New feature:

   - implement statx

  The new implementation of dir.c is kind of a big deal, all new code.
  It has been posted to fs-devel during the previous rc period, we
  didn't get much review or feedback from there, but it has been
  reviewed very heavily here, so much so that we have two entire
  versions of the reimplementation.

  Not only does the new implementation fix some xfstests, but it passes
  all the new tests we made here that involve seeking and rewinding and
  giant directories and long file names. The new dir code has three
  patches itself:

   - skip forward to the next directory entry if seek is short
   - invalidate stored directory on seek
   - count directory pieces correctly"

* tag 'for-linus-4.12-ofs-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: count directory pieces correctly
  orangefs: invalidate stored directory on seek
  orangefs: skip forward to the next directory entry if seek is short
  orangefs: handle zero size write in debugfs
  orangefs: do not wait for timeout if umounting
  orangefs: return from orangefs_devreq_read quickly if possible
  orangefs: ensure the userspace component is unmounted if mount fails
  orangefs: do not check possibly stale size on truncate
  orangefs: implement statx
  orangefs: remove ORANGEFS_READDIR macros
  orangefs: support very large directories
  orangefs: support llseek on directories
  orangefs: rewrite readdir to fix several bugs
  orangefs: do not set getattr_time on orangefs_lookup
  orangefs: clean up oversize xattr validation
  orangefs: fix bounds check for listxattr
  orangefs: remove unused get_fsid_from_ino

fs/orangefs/devorangefs-req.c

@@ -180,6 +180,10 @@ static ssize_t orangefs_devreq_read(struct file *file,
 		return -EINVAL;
 	}
 
+	/* Check for an empty list before locking. */
+	if (list_empty(&orangefs_request_list))
+		return -EAGAIN;
+
 restart:
 	/* Get next op (if any) from top of list. */
 	spin_lock(&orangefs_request_list_lock);