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, 0 insertions, 32 deletions

diff --git a/sys/fs/tmpfs/tmpfs_vnops.c b/sys/fs/tmpfs/tmpfs_vnops.c
index f50af94..719a5de 100644
--- a/sys/fs/tmpfs/tmpfs_vnops.c
+++ b/sys/fs/tmpfs/tmpfs_vnops.c
@@ -1429,36 +1429,6 @@ tmpfs_pathconf(struct vop_pathconf_args *v)
 	return error;
 }
 
-/* --------------------------------------------------------------------- */
-
-static int
-tmpfs_advlock(struct vop_advlock_args *v)
-{
-	struct vnode *vp = v->a_vp;
-
-	struct tmpfs_node *node;
-
-	node = VP_TO_TMPFS_NODE(vp);
-
-	return lf_advlock(v, &node->tn_lockf, node->tn_size);
-}
-
-/* --------------------------------------------------------------------- */
-
-static int
-tmpfs_advlockasync(struct vop_advlockasync_args *v)
-{
-	struct vnode *vp = v->a_vp;
-
-	struct tmpfs_node *node;
-
-	node = VP_TO_TMPFS_NODE(vp);
-
-	return lf_advlockasync(v, &node->tn_lockf, node->tn_size);
-}
-
-/* --------------------------------------------------------------------- */
-
 static int
 tmpfs_vptofh(struct vop_vptofh_args *ap)
 {
@@ -1506,8 +1476,6 @@ struct vop_vector tmpfs_vnodeop_entries = {
 	.vop_reclaim =			tmpfs_reclaim,
 	.vop_print =			tmpfs_print,
 	.vop_pathconf =			tmpfs_pathconf,
-	.vop_advlock =			tmpfs_advlock,
-	.vop_advlockasync =		tmpfs_advlockasync,
 	.vop_vptofh =			tmpfs_vptofh,
 	.vop_bmap =			VOP_EOPNOTSUPP,
 };