VFS,locks: locks: don't unnecessarily fail posix lock operations

---

 fs/locks.c |   27 ++++++++++++++++++++-------
 1 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index 6ba3756..973c1d9 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -839,10 +839,6 @@ static int __posix_lock_file_conf(struct
 	if (request->fl_flags & FL_ACCESS)
 		goto out;
 
-	error = -ENOLCK; /* "no luck" */
-	if (!(new_fl && new_fl2))
-		goto out;
-
 	/*
 	 * We've allocated the new locks in advance, so there are no
 	 * errors possible (and no blocking operations) from here on.
@@ -943,9 +939,25 @@ static int __posix_lock_file_conf(struct
 		before = &fl->fl_next;
 	}
 
-	error = 0;
-	if (!added) {
-		if (request->fl_type == F_UNLCK)
+	if (request->fl_type == F_UNLCK) {
+		if (!added)
+			goto out;
+		if (!new_fl2 && right && left == right) {
+			new_fl2 = new_fl;
+			error = -ENOLCK;
+			if (!new_fl2)
+				goto out;
+			new_fl = NULL;
+		}
+	} else if (!added) {
+		error = -ENOLCK;
+		if (!new_fl) {
+			new_fl = new_fl2;
+			if (!new_fl)
+				goto out;
+			new_fl2 = NULL;
+		}
+		if (!new_fl2 && right && left == right)
 			goto out;
 		locks_copy_lock(new_fl, request);
 		locks_insert_lock(before, new_fl);
@@ -968,6 +980,7 @@ static int __posix_lock_file_conf(struct
 		left->fl_end = request->fl_start - 1;
 		locks_wake_up_blocks(left);
 	}
+	error = 0;
  out:
 	unlock_kernel();
 	/*