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

3 files changed, 3 insertions, 24 deletions

diff --git a/sys/gnu/fs/ext2fs/ext2_vnops.c b/sys/gnu/fs/ext2fs/ext2_vnops.c
index eaf7443..76d2cc1 100644
--- a/sys/gnu/fs/ext2fs/ext2_vnops.c
+++ b/sys/gnu/fs/ext2fs/ext2_vnops.c
@@ -83,7 +83,6 @@
 static int ext2_makeinode(int mode, struct vnode *, struct vnode **, struct componentname *);
 
 static vop_access_t	ext2_access;
-static vop_advlock_t	ext2_advlock;
 static int ext2_chmod(struct vnode *, int, struct ucred *, struct thread *);
 static int ext2_chown(struct vnode *, uid_t, gid_t, struct ucred *,
     struct thread *);
@@ -119,7 +118,6 @@ static void filt_ext2detach(struct knote *kn);
 struct vop_vector ext2_vnodeops = {
 	.vop_default =		&default_vnodeops,
 	.vop_access =		ext2_access,
-	.vop_advlock =		ext2_advlock,
 	.vop_bmap =		ext2_bmap,
 	.vop_cachedlookup =	ext2_lookup,
 	.vop_close =		ext2_close,
@@ -1521,24 +1519,6 @@ ext2_pathconf(ap)
 }
 
 /*
- * Advisory record locking support
- */
-static int
-ext2_advlock(ap)
-	struct vop_advlock_args /* {
-		struct vnode *a_vp;
-		caddr_t  a_id;
-		int  a_op;
-		struct flock *a_fl;
-		int  a_flags;
-	} */ *ap;
-{
-	struct inode *ip = VTOI(ap->a_vp);
-
-	return (lf_advlock(ap, &(ip->i_lockf), ip->i_size));
-}
-
-/*
  * Vnode pointer to File handle
  */
 /* ARGSUSED */
diff --git a/sys/gnu/fs/ext2fs/inode.h b/sys/gnu/fs/ext2fs/inode.h
index 9ba5546..75d9b1b 100644
--- a/sys/gnu/fs/ext2fs/inode.h
+++ b/sys/gnu/fs/ext2fs/inode.h
@@ -68,7 +68,6 @@ struct inode {
 
 	struct	ext2_sb_info *i_e2fs;	/* EXT2FS */
 	u_quad_t i_modrev;	/* Revision level for NFS lease. */
-	struct	 lockf *i_lockf;/* Head of byte-level lock list. */
 	/*
 	 * Side effects; used during directory lookup.
 	 */
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);