Move the head of byte-level advisory lock list from the

filesystem-specific vnode data to the struct vnode. Provide the
default implementation for the vop_advlock and vop_advlockasync.
Purge the locks on the vnode reclaim by using the lf_purgelocks().
The default implementation is augmented for the nfs and smbfs.
In the nfs_advlock, push the Giant inside the nfs_dolock.

Before the change, the vop_advlock and vop_advlockasync have taken the
unlocked vnode and dereferenced the fs-private inode data, racing with
with the vnode reclamation due to forced unmount. Now, the vop_getattr
under the shared vnode lock is used to obtain the inode size, and
later, in the lf_advlockasync, after locking the vnode interlock, the
VI_DOOMED flag is checked to prevent an operation on the doomed vnode.

The implementation of the lf_purgelocks() is submitted by dfr.

Reported by:	kris
Tested by:	kris, pho
Discussed with:	jeff, dfr
MFC after:	2 weeks

1 files changed, 3 insertions, 3 deletions

diff --git a/sys/gnu/fs/xfs/FreeBSD/xfs_vnops.c b/sys/gnu/fs/xfs/FreeBSD/xfs_vnops.c
index 90a0b48..1027416 100644
--- a/sys/gnu/fs/xfs/FreeBSD/xfs_vnops.c
+++ b/sys/gnu/fs/xfs/FreeBSD/xfs_vnops.c
@@ -1231,13 +1231,13 @@ _xfs_advlock(
 #ifdef notyet
 	switch (ap->a_op) {
 	    case F_SETLK:
-		error = lf_advlock(ap, &np->n_lockf, size);
+		error = lf_advlock(ap, &vp->v_lockf, size);
 		break;
 	    case F_UNLCK:
-		lf_advlock(ap, &np->n_lockf, size);
+		lf_advlock(ap, &vp->v_lockf, size);
 		break;
 	    case F_GETLK:
-		error = lf_advlock(ap, &np->n_lockf, size);
+		error = lf_advlock(ap, &vp->v_lockf, size);
 		break;
 	    default:
 		return (EINVAL);