add Yuval Yarom's changes (originally for BSD/386) for advisory record

locking on NFS files.  Note that this DOES NOT support network locking,
only local advisory locks.

sys/nfs/nfs_vnops.c

@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)nfs_vnops.c	7.60 (Berkeley) 5/24/91
- *	$Id: nfs_vnops.c,v 1.4 1993/05/21 07:38:07 cgd Exp $
+ *	$Id: nfs_vnops.c,v 1.5 1993/05/22 09:00:49 cgd Exp $
  */
 
 /*
@@ -1709,8 +1709,9 @@ nfs_advlock(vp, id, op, fl, flags)
 	struct flock *fl;
 	int flags;
 {
+	register struct nfsnode *np = VTONFS(vp);
 
-	return (EOPNOTSUPP);
+	return (lf_advlock(&(np->n_lockf), np->n_size, id, op, fl, flags));
 }
 
 /*

sys/nfs/nfsnode.h

@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)nfsnode.h	7.12 (Berkeley) 4/16/91
- *	$Id: nfsnode.h,v 1.2 1993/05/20 03:19:11 cgd Exp $
+ *	$Id: nfsnode.h,v 1.3 1993/05/22 09:00:56 cgd Exp $
  */
 
 #ifndef _NFS_NFSNODE_H_
@@ -57,6 +57,7 @@ struct nfsnode {
 	struct	vattr n_vattr;	/* Vnode attribute cache */
 	struct	sillyrename *n_sillyrename;	/* Ptr to silly rename struct */
 	u_long	n_size;		/* Current size of file */
+	struct lockf *n_lockf; 	/* Locking record of file */
 	time_t	n_mtime;	/* Prev modify time to maintain data cache consistency*/
 	time_t	n_ctime;	/* Prev create time for name cache consistency*/
 	int	n_error;	/* Save write error value */

sys/ufs/lockf.h

@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)lockf.h	7.1 (Berkeley) 2/1/91
- *	$Id: lockf.h,v 1.3 1993/05/20 03:53:25 cgd Exp $
+ *	$Id: lockf.h,v 1.4 1993/05/22 09:01:13 cgd Exp $
  */
 
 #ifndef _UFS_LOCKF_H_
@@ -52,7 +52,7 @@ struct lockf {
 	off_t	lf_start;	 /* The byte # of the start of the lock */
 	off_t	lf_end;		 /* The byte # of the end of the lock (-1=EOF)*/
 	caddr_t	lf_id;		 /* The id of the resource holding the lock */
-	struct	inode *lf_inode; /* Back pointer to the inode */
+	struct	lockf **lf_head; /* Back pointer to the head of lockf list */
 	struct	lockf *lf_next;	 /* A pointer to the next lock on this inode */
 	struct	lockf *lf_block; /* The list of blocked locks */
 };

sys/ufs/ufs_lockf.c

@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)ufs_lockf.c	7.7 (Berkeley) 7/2/91
- *	$Id: ufs_lockf.c,v 1.3 1993/05/20 03:53:38 cgd Exp $
+ *	$Id: ufs_lockf.c,v 1.4 1993/05/22 09:01:16 cgd Exp $
  */
 
 #include "param.h"
@@ -50,6 +50,96 @@
 #include "quota.h"
 #include "inode.h"
 
+
+
+/*
+ * Advisory record locking support
+ */
+lf_advlock(head, size, id, op, fl, flags)
+	struct lockf **head;
+	u_long size;
+	caddr_t id;
+	int op;
+	register struct flock *fl;
+	int flags;
+{
+	register struct lockf *lock;
+	off_t start, end;
+	int error;
+
+	/*
+	 * Avoid the common case of unlocking when inode has no locks.
+	 */
+	if (*head == (struct lockf *)0) {
+		if (op != F_SETLK) {
+			fl->l_type = F_UNLCK;
+			return (0);
+		}
+	}
+
+	/*
+	 * Convert the flock structure into a start and end.
+	 */
+	switch (fl->l_whence) {
+
+	case SEEK_SET:
+	case SEEK_CUR:
+		/*
+		 * Caller is responsible for adding any necessary offset
+		 * when SEEK_CUR is used.
+		 */
+		start = fl->l_start;
+		break;
+
+	case SEEK_END:
+		start = size + fl->l_start;
+		break;
+
+	default:
+		return (EINVAL);
+	}
+	if (start < 0)
+		return (EINVAL);
+	if (fl->l_len == 0)
+		end = -1;
+	else
+		end = start + fl->l_len - 1;
+	/*
+	 * Create the lockf structure
+	 */
+	MALLOC(lock, struct lockf *, sizeof *lock, M_LOCKF, M_WAITOK);
+	lock->lf_start = start;
+	lock->lf_end = end;
+	lock->lf_id = id;
+	lock->lf_head = head;
+	lock->lf_type = fl->l_type;
+	lock->lf_next = (struct lockf *)0;
+	lock->lf_block = (struct lockf *)0;
+	lock->lf_flags = flags;
+	/*
+	 * Do the requested operation.
+	 */
+	switch(op) {
+	case F_SETLK:
+		return (lf_setlock(lock));
+
+	case F_UNLCK:
+		error = lf_clearlock(lock);
+		FREE(lock, M_LOCKF);
+		return (error);
+
+	case F_GETLK:
+		error = lf_getlock(lock, fl);
+		FREE(lock, M_LOCKF);
+		return (error);
+	
+	default:
+		free(lock, M_LOCKF);
+		return (EINVAL);
+	}
+	/* NOTREACHED */
+}
+
 /*
  * This variable controls the maximum number of processes that will
  * be checked in doing deadlock detection.
@@ -71,7 +161,7 @@ lf_setlock(lock)
 	register struct lockf *lock;
 {
 	register struct lockf *block;
-	struct inode *ip = lock->lf_inode;
+	struct lockf **head = lock->lf_head;
 	struct lockf **prev, *overlap, *ltmp;
 	static char lockstr[] = "lockf";
 	int ovcase, priority, needtolink, error;
@@ -182,8 +272,8 @@ lf_setlock(lock)
 	 * Skip over locks owned by other processes.
 	 * Handle any locks that overlap and are owned by ourselves.
 	 */
-	prev = &ip->i_lockf;
-	block = ip->i_lockf;
+	prev = head;
+	block = *head;
 	needtolink = 1;
 	for (;;) {
 		if (ovcase = lf_findoverlap(block, lock, SELF, &prev, &overlap))
@@ -306,8 +396,8 @@ lf_setlock(lock)
 lf_clearlock(unlock)
 	register struct lockf *unlock;
 {
-	struct inode *ip = unlock->lf_inode;
-	register struct lockf *lf = ip->i_lockf;
+	struct lockf **head = unlock->lf_head;
+	register struct lockf *lf = *head;
 	struct lockf *overlap, **prev;
 	int ovcase;
 
@@ -319,7 +409,7 @@ lf_clearlock(unlock)
 	if (lockf_debug & 1)
 		lf_print("lf_clearlock", unlock);
 #endif /* LOCKF_DEBUG */
-	prev = &ip->i_lockf;
+	prev = head;
 	while (ovcase = lf_findoverlap(lf, unlock, SELF, &prev, &overlap)) {
 		/*
 		 * Wakeup the list of locks to be retried.
@@ -409,10 +499,10 @@ struct lockf *
 lf_getblock(lock)
 	register struct lockf *lock;
 {
-	struct lockf **prev, *overlap, *lf = lock->lf_inode->i_lockf;
+	struct lockf **prev, *overlap, *lf = *(lock->lf_head);
 	int ovcase;
 
-	prev = &lock->lf_inode->i_lockf;
+	prev = lock->lf_head;
 	while (ovcase = lf_findoverlap(lf, lock, OTHERS, &prev, &overlap)) {
 		/*
 		 * We've found an overlap, see if it blocks us