[PATCH v2 1/8] locks: make flock_lock_file take is_conflict callback parm

[Pavel Shilovsky <piastry-7qunaywFIewox3rIn2DAYQ@public.gmane.org>]

This parm demetermines how to check if locks have conflicts.
This let us use flock_lock_file funtions further to add
O_DENY* flags support through flocks.

Signed-off-by: Pavel Shilovsky <piastry-7qunaywFIewox3rIn2DAYQ@public.gmane.org>
---
 fs/locks.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index a94e331..9edfec4 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -697,14 +697,20 @@ static int posix_locks_deadlock(struct file_lock *caller_fl,
 	return 0;
 }
 
-/* Try to create a FLOCK lock on filp. We always insert new FLOCK locks
+/*
+ * Try to create a FLOCK lock on filp. We always insert new FLOCK locks
  * after any leases, but before any posix locks.
  *
  * Note that if called with an FL_EXISTS argument, the caller may determine
  * whether or not a lock was successfully freed by testing the return
  * value for -ENOENT.
+ *
+ * Take @is_conflict callback that determines how to check if locks have
+ * conflicts or not.
  */
-static int flock_lock_file(struct file *filp, struct file_lock *request)
+static int
+flock_lock_file(struct file *filp, struct file_lock *request,
+		int (*is_conflict)(struct file_lock *, struct file_lock *))
 {
 	struct file_lock *new_fl = NULL;
 	struct file_lock **before;
@@ -760,7 +766,7 @@ find_conflict:
 			break;
 		if (IS_LEASE(fl))
 			continue;
-		if (!flock_locks_conflict(request, fl))
+		if (!is_conflict(request, fl))
 			continue;
 		error = -EAGAIN;
 		if (!(request->fl_flags & FL_SLEEP))
@@ -1589,7 +1595,7 @@ int flock_lock_file_wait(struct file *filp, struct file_lock *fl)
 	int error;
 	might_sleep();
 	for (;;) {
-		error = flock_lock_file(filp, fl);
+		error = flock_lock_file(filp, fl, flock_locks_conflict);
 		if (error != FILE_LOCK_DEFERRED)
 			break;
 		error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
-- 
1.8.1.1