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

2 files changed, 0 insertions, 42 deletions

diff --git a/sys/ufs/ufs/inode.h b/sys/ufs/ufs/inode.h
index 2fc3336..b198758 100644
--- a/sys/ufs/ufs/inode.h
+++ b/sys/ufs/ufs/inode.h
@@ -75,7 +75,6 @@ struct inode {
 	struct	 fs *i_fs;	/* Associated filesystem superblock. */
 	struct	 dquot *i_dquot[MAXQUOTAS]; /* Dquot structures. */
 	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/ufs/ufs/ufs_vnops.c b/sys/ufs/ufs/ufs_vnops.c
index d65d1fb..5028975 100644
--- a/sys/ufs/ufs/ufs_vnops.c
+++ b/sys/ufs/ufs/ufs_vnops.c
@@ -91,8 +91,6 @@ __FBSDID("$FreeBSD$");
 #include <ufs/ffs/ffs_extern.h>
 
 static vop_access_t	ufs_access;
-static vop_advlock_t	ufs_advlock;
-static vop_advlockasync_t ufs_advlockasync;
 static int ufs_chmod(struct vnode *, int, struct ucred *, struct thread *);
 static int ufs_chown(struct vnode *, uid_t, gid_t, struct ucred *, struct thread *);
 static vop_close_t	ufs_close;
@@ -2165,43 +2163,6 @@ ufs_pathconf(ap)
 }
 
 /*
- * Advisory record locking support
- */
-static int
-ufs_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));
-}
-
-/*
- * Advisory record locking support
- */
-static int
-ufs_advlockasync(ap)
-	struct vop_advlockasync_args /* {
-		struct vnode *a_vp;
-		caddr_t  a_id;
-		int  a_op;
-		struct flock *a_fl;
-		int  a_flags;
-		struct task *a_task;
-	} */ *ap;
-{
-	struct inode *ip = VTOI(ap->a_vp);
-
-	return (lf_advlockasync(ap, &(ip->i_lockf), ip->i_size));
-}
-
-/*
  * Initialize the vnode associated with a new inode, handle aliased
  * vnodes.
  */
@@ -2468,8 +2429,6 @@ struct vop_vector ufs_vnodeops = {
 	.vop_reallocblks =	VOP_PANIC,
 	.vop_write =		VOP_PANIC,
 	.vop_access =		ufs_access,
-	.vop_advlock =		ufs_advlock,
-	.vop_advlockasync =	ufs_advlockasync,
 	.vop_bmap =		ufs_bmap,
 	.vop_cachedlookup =	ufs_lookup,
 	.vop_close =		ufs_close,