locks: Set FL_CLOSE when removing flock locks on close()

Set FL_CLOSE in fl_flags as in locks_remove_posix() when clearing locks.
NFS will check for this flag to ensure an unlock is sent in a following
patch.

Fuse handles flock and posix locks differently for FL_CLOSE, and so
requires a fixup to retain the existing behavior for flock.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/fuse/file.c

@@ -2168,7 +2168,7 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
 	}
 
 	/* Unlock on close is handled by the flush method */
-	if (fl->fl_flags & FL_CLOSE)
+	if ((fl->fl_flags & FL_CLOSE_POSIX) == FL_CLOSE_POSIX)
 		return 0;
 
 	fuse_lk_fill(&args, file, fl, opcode, pid, flock, &inarg);

fs/locks.c

@@ -2504,7 +2504,7 @@ locks_remove_flock(struct file *filp, struct file_lock_context *flctx)
 		.fl_owner = filp,
 		.fl_pid = current->tgid,
 		.fl_file = filp,
-		.fl_flags = FL_FLOCK,
+		.fl_flags = FL_FLOCK | FL_CLOSE,
 		.fl_type = F_UNLCK,
 		.fl_end = OFFSET_MAX,
 	};

include/linux/fs.h

@@ -909,6 +909,8 @@ static inline struct file *get_file(struct file *f)
 #define FL_OFDLCK	1024	/* lock is "owned" by struct file */
 #define FL_LAYOUT	2048	/* outstanding pNFS layout */
 
+#define FL_CLOSE_POSIX (FL_POSIX | FL_CLOSE)
+
 /*
  * Special return value from posix_lock_file() and vfs_lock_file() for
  * asynchronous locking.