Prepare to replace the buf splay with a trie:

 - Don't insert BKGRDMARKER bufs into the splay or dirty/clean buf lists.
   No consumers need to find them there and it complicates the tree.
   These flags are all FFS specific and could be moved out of the buf
   cache.
 - Use pbgetvp() and pbrelvp() to associate the background and journal
   bufs with the vp.  Not only is this much cheaper it makes more sense
   for these transient bufs.
 - Fix the assertions in pbget* and pbrel*.  It's not safe to check list
   pointers which were never initialized.  Use the BX flags instead.  We
   also check B_PAGING in reassignbuf() so this should cover all cases.

Discussed with:	kib, mckusick, attilio
Sponsored by:	EMC / Isilon Storage Division

1 files changed, 4 insertions, 20 deletions

diff --git a/sys/vm/vm_pager.c b/sys/vm/vm_pager.c
index a991e41..989c318 100644
--- a/sys/vm/vm_pager.c
+++ b/sys/vm/vm_pager.c
@@ -469,17 +469,9 @@ pbrelvp(struct buf *bp)
 
 	KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL"));
 	KASSERT(bp->b_bufobj != NULL, ("pbrelvp: NULL bufobj"));
+	KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == 0,
+	    ("pbrelvp: pager buf on vnode list."));
 
-	/* XXX REMOVE ME */
-	BO_LOCK(bp->b_bufobj);
-	if (TAILQ_NEXT(bp, b_bobufs) != NULL) {
-		panic(
-		    "relpbuf(): b_vp was probably reassignbuf()d %p %x",
-		    bp,
-		    (int)bp->b_flags
-		);
-	}
-	BO_UNLOCK(bp->b_bufobj);
 	bp->b_vp = NULL;
 	bp->b_bufobj = NULL;
 	bp->b_flags &= ~B_PAGING;
@@ -494,17 +486,9 @@ pbrelbo(struct buf *bp)
 
 	KASSERT(bp->b_vp == NULL, ("pbrelbo: vnode"));
 	KASSERT(bp->b_bufobj != NULL, ("pbrelbo: NULL bufobj"));
+	KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == 0,
+	    ("pbrelbo: pager buf on vnode list."));
 
-	/* XXX REMOVE ME */
-	BO_LOCK(bp->b_bufobj);
-	if (TAILQ_NEXT(bp, b_bobufs) != NULL) {
-		panic(
-		    "relpbuf(): b_vp was probably reassignbuf()d %p %x",
-		    bp,
-		    (int)bp->b_flags
-		);
-	}
-	BO_UNLOCK(bp->b_bufobj);
 	bp->b_bufobj = NULL;
 	bp->b_flags &= ~B_PAGING;
 }