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@etersoft.ru --- 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);