sys/kern/kern_lockf.c

176  * POSIX fcntl locks, local file for BSD flock locks or <pid,sysid>
177  * pair for remote locks) is represented by a unique instance of
195 	int	lo_refs;	    /* (l) Number of locks referring to this */
213  * We have two types of directed graph, the first is the set of locks,
214  * both active and pending on a vnode. Within this graph, active locks
216  * edges). Pending locks have out-going edges to each blocking active
220  * added to or from new nodes (either new pending locks which only add
221  * out-going edges or new active locks which only add in-coming edges)
272  * Initialise various structures and locks.
473 	 * Avoid the common case of unlocking when inode has no locks.
555 		 * For remote locks, the caller may release its ref to
645 	 * pending locks when vnode is marked by VI_DOOMED flag.
691 	 * blocking locks. We also check the pending list for locks
699 			    ("locks disordered"));
704 			    ("two conflicting active locks"));
707 				    ("two overlapping locks from same owner"));
733 		    ("freeing state with pending locks"));
776 	 * sleeping waiting for locks on this vnode and then free all
777 	 * the remaining locks.
820 		 * We can just free all the active locks since they
842  * Return non-zero if locks 'x' and 'y' overlap.
979  * Walk the list of locks for the file and create an out-going edge
1016 	 * We also need to add edges to sleeping locks that block
1018 	 * mutually blocking locks simultaneously and also enforces a
1047  * Walk the list of pending locks for the file and create an in-coming
1108  * existing locks for the same owner as needed.
1131  * Re-check all dependant locks and remove edges to locks that we no
1134  * reduced but remains active. Any pending locks which have been been
1160  * adding any newly woken locks to 'granted'.
1176  * adding any newly woken locks to 'granted'.
1190  * locks owned by the same owner and processing any pending locks that
1192  * since the logic for updating existing locks is identical.
1195  * pending locks as a result of downgrading/unlocking. We simply
1196  * activate the newly granted locks by looping.
1218 		 * Skip over locks owned by other processes.  Handle
1219 		 * any locks that overlap and are owned by ourselves.
1355 	 * Feed any newly active locks to lf_activate_lock.
1388 	 * Scan lock list for this file looking for locks that would block us.
1402 		 * For flock type locks, we must first remove
1403 		 * any shared locks that we hold before we sleep
1417 		 * locks, posix and otherwise.
1524 	 * downgrade or upgrade any overlapping locks this
1643  * Walk the list of locks for an inode and
1666  * Walk the list of locks for an inode to find an overlapping lock (if
1672  *	type		Pass 'SELF' to test only locks with the same
1673  *			owner as lock, or 'OTHER' to test only locks
1795  * Any pending locks which have been been unblocked are added to
1866 	struct lockdesclist locks;
1871 	 * active lock lists to build a list of locks that need
1877 	STAILQ_INIT(&locks);
1899 			STAILQ_INSERT_TAIL(&locks, ldesc, link);
1911 	while ((ldesc = STAILQ_FIRST(&locks)) != NULL) {
1912 		STAILQ_REMOVE_HEAD(&locks, link);
1928 	struct lockdesclist locks;
1933 	 * active lock lists to build a list of locks that need
1939 	STAILQ_INIT(&locks);
1965 		STAILQ_INSERT_TAIL(&locks, ldesc, link);
1979 	while ((ldesc = STAILQ_FIRST(&locks)) != NULL) {
1980 		STAILQ_REMOVE_HEAD(&locks, link);
2002 	KASSERT(sysid != 0, ("Can't clear local locks with F_UNLCKSYS"));