--- //depot/vendor/freebsd/src/sys/gnu/fs/xfs/FreeBSD/xfs_buf.c	2006/06/09 06:06:46
+++ //depot/user/attilio/attilio_schedlock/gnu/fs/xfs/FreeBSD/xfs_buf.c	2008/01/18 23:33:23
@@ -86,7 +86,7 @@
 		bp->b_bufsize = size;
 		bp->b_bcount = size;
 
-		KASSERT(BUF_REFCNT(bp) == 1,
+		KASSERT(BUF_ISLOCKED(bp),
 			("xfs_buf_get_empty: bp %p not locked",bp));
 
 		xfs_buf_set_target(bp, target);
@@ -103,7 +103,7 @@
 
 	bp = geteblk(len);
 	if (bp != NULL) {
-		KASSERT(BUF_REFCNT(bp) == 1,
+		KASSERT(BUF_ISLOCKED(bp),
 			("xfs_buf_get_empty: bp %p not locked",bp));
 
 		xfs_buf_set_target(bp, target);
@@ -163,7 +163,7 @@
 		if ((bp->b_flags & B_ASYNC) == 0) {
 			error = bufwait(bp);
 #if 0
-			if (BUF_REFCNT(bp) > 1)
+			if (BUF_LOCKRECURSED(bp))
 				BUF_UNLOCK(bp);
 			else
 				brelse(bp);
--- //depot/vendor/freebsd/src/sys/gnu/fs/xfs/FreeBSD/xfs_buf.h	2006/06/09 06:06:46
+++ //depot/user/attilio/attilio_schedlock/gnu/fs/xfs/FreeBSD/xfs_buf.h	2008/01/18 23:33:23
@@ -160,7 +160,6 @@
 
 #define XFS_BUF_HOLD(x)		((void)0)
 #define XFS_BUF_UNHOLD(x)	((void)0)
-#define XFS_BUF_ISHOLD(x)	BUF_REFCNT(x)
 
 #define XFS_BUF_READ(x)		((x)->b_iocmd = BIO_READ)
 #define XFS_BUF_UNREAD(x)	((x)->b_iocmd = 0)
@@ -234,7 +233,7 @@
 #define	XFS_BUF_SET_VTYPE(bp, type)
 #define	XFS_BUF_SET_REF(bp, ref)
 
-#define	XFS_BUF_VALUSEMA(bp)	(BUF_REFCNT(bp)? 0 : 1)
+#define	XFS_BUF_VALUSEMA(bp)	(BUF_ISLOCKED(bp) ? 0 : 1)
 #define	XFS_BUF_CPSEMA(bp) \
 	(BUF_LOCK(bp, LK_EXCLUSIVE|LK_CANRECURSE | LK_SLEEPFAIL, NULL) == 0)
 
--- //depot/vendor/freebsd/src/sys/kern/kern_shutdown.c	2007/12/26 11:36:13
+++ //depot/user/attilio/attilio_schedlock/kern/kern_shutdown.c	2008/01/18 23:33:23
@@ -255,7 +255,7 @@
 isbufbusy(struct buf *bp)
 {
 	if (((bp->b_flags & (B_INVAL | B_PERSISTENT)) == 0 &&
-	    BUF_REFCNT(bp) > 0) ||
+	    BUF_ISLOCKED(bp)) ||
 	    ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI))
 		return (1);
 	return (0);
--- //depot/vendor/freebsd/src/sys/kern/vfs_bio.c	2008/01/13 14:45:30
+++ //depot/user/attilio/attilio_schedlock/kern/vfs_bio.c	2008/01/18 23:33:23
@@ -658,7 +658,7 @@
 {
 
 	CTR3(KTR_BUF, "bremfree(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
-	KASSERT(BUF_REFCNT(bp), ("bremfree: buf must be locked."));
+	KASSERT(BUF_ISLOCKED(bp), ("bremfree: buf must be locked."));
 	KASSERT((bp->b_flags & B_REMFREE) == 0,
 	    ("bremfree: buffer %p already marked for delayed removal.", bp));
 	KASSERT(bp->b_qindex != QUEUE_NONE,
@@ -695,7 +695,7 @@
 {
 	CTR3(KTR_BUF, "bremfreel(%p) vp %p flags %X",
 	    bp, bp->b_vp, bp->b_flags);
-	KASSERT(BUF_REFCNT(bp), ("bremfreel: buffer %p not locked.", bp));
+	KASSERT(BUF_ISLOCKED(bp), ("bremfreel: buffer %p not locked.", bp));
 	KASSERT(bp->b_qindex != QUEUE_NONE,
 	    ("bremfreel: buffer %p not on a queue.", bp));
 	mtx_assert(&bqlock, MA_OWNED);
@@ -834,7 +834,7 @@
 
 	oldflags = bp->b_flags;
 
-	if (BUF_REFCNT(bp) == 0)
+	if (!BUF_ISLOCKED(bp))
 		panic("bufwrite: buffer is not busy???");
 
 	if (bp->b_pin_count > 0)
@@ -952,7 +952,7 @@
 
 	CTR3(KTR_BUF, "bdwrite(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
 	KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
-	KASSERT(BUF_REFCNT(bp) != 0, ("bdwrite: buffer is not busy"));
+	KASSERT(BUF_ISLOCKED(bp), ("bdwrite: buffer is not busy"));
 
 	if (bp->b_flags & B_INVAL) {
 		brelse(bp);
@@ -1047,7 +1047,7 @@
 
 	CTR3(KTR_BUF, "bdirty(%p) vp %p flags %X",
 	    bp, bp->b_vp, bp->b_flags);
-	KASSERT(BUF_REFCNT(bp) == 1, ("bdirty: bp %p not locked",bp));
+	KASSERT(BUF_ISLOCKED(bp), ("bdirty: bp %p not locked",bp));
 	KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
 	KASSERT(bp->b_flags & B_REMFREE || bp->b_qindex == QUEUE_NONE,
 	    ("bdirty: buffer %p still on queue %d", bp, bp->b_qindex));
@@ -1081,7 +1081,7 @@
 	KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
 	KASSERT(bp->b_flags & B_REMFREE || bp->b_qindex == QUEUE_NONE,
 	    ("bundirty: buffer %p still on queue %d", bp, bp->b_qindex));
-	KASSERT(BUF_REFCNT(bp) == 1, ("bundirty: bp %p not locked",bp));
+	KASSERT(BUF_ISLOCKED(bp), ("bundirty: bp %p not locked",bp));
 
 	if (bp->b_flags & B_DELWRI) {
 		bp->b_flags &= ~B_DELWRI;
@@ -1341,7 +1341,7 @@
 			brelvp(bp);
 	}
 			
-	if (BUF_REFCNT(bp) > 1) {
+	if (BUF_LOCKRECURSED(bp)) {
 		/* do not release to free list */
 		BUF_UNLOCK(bp);
 		return;
@@ -1446,7 +1446,7 @@
 	KASSERT(!(bp->b_flags & (B_CLUSTER|B_PAGING)),
 	    ("bqrelse: inappropriate B_PAGING or B_CLUSTER bp %p", bp));
 
-	if (BUF_REFCNT(bp) > 1) {
+	if (BUF_LOCKRECURSED(bp)) {
 		/* do not release to free list */
 		BUF_UNLOCK(bp);
 		return;
@@ -2660,7 +2660,7 @@
 		bp->b_flags &= ~B_DONE;
 	}
 	CTR4(KTR_BUF, "getblk(%p, %ld, %d) = %p", vp, (long)blkno, size, bp);
-	KASSERT(BUF_REFCNT(bp) == 1, ("getblk: bp %p not locked",bp));
+	KASSERT(BUF_ISLOCKED(bp), ("getblk: bp %p not locked",bp));
 	KASSERT(bp->b_bufobj == bo,
 	    ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
 	return (bp);
@@ -2681,7 +2681,7 @@
 		continue;
 	allocbuf(bp, size);
 	bp->b_flags |= B_INVAL;	/* b_dep cleared by getnewbuf() */
-	KASSERT(BUF_REFCNT(bp) == 1, ("geteblk: bp %p not locked",bp));
+	KASSERT(BUF_ISLOCKED(bp), ("geteblk: bp %p not locked",bp));
 	return (bp);
 }
 
@@ -2707,7 +2707,7 @@
 	int newbsize, mbsize;
 	int i;
 
-	if (BUF_REFCNT(bp) == 0)
+	if (!BUF_ISLOCKED(bp))
 		panic("allocbuf: buffer not busy");
 
 	if (bp->b_kvasize < size)
@@ -3150,8 +3150,7 @@
 	CTR3(KTR_BUF, "bufdone(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
 	dropobj = NULL;
 
-	KASSERT(BUF_REFCNT(bp) > 0, ("biodone: bp %p not busy %d", bp,
-	    BUF_REFCNT(bp)));
+	KASSERT(BUF_ISLOCKED(bp), ("biodone: bp %p not busy", bp));
 	KASSERT(!(bp->b_flags & B_DONE), ("biodone: bp %p already done", bp));
 
 	runningbufwakeup(bp);
@@ -3176,8 +3175,7 @@
 void
 bufdone_finish(struct buf *bp)
 {
-	KASSERT(BUF_REFCNT(bp) > 0, ("biodone: bp %p not busy %d", bp,
-	    BUF_REFCNT(bp)));
+	KASSERT(BUF_ISLOCKED(bp), ("biodone: bp %p not busy", bp));
 
 	if (!LIST_EMPTY(&bp->b_dep))
 		buf_complete(bp);
@@ -3943,7 +3941,7 @@
 
 	for (i = 0; i < nbuf; i++) {
 		bp = &buf[i];
-		if (lockcount(&bp->b_lock)) {
+		if (BUF_ISLOCKED(bp)) {
 			db_show_buffer((uintptr_t)bp, 1, 0, NULL);
 			db_printf("\n");
 		}
--- //depot/vendor/freebsd/src/sys/kern/vfs_subr.c	2008/01/13 14:45:30
+++ //depot/user/attilio/attilio_schedlock/kern/vfs_subr.c	2008/01/18 23:33:23
@@ -3570,7 +3570,7 @@
 	if ((bp->b_flags & B_CLUSTER) != 0)
 		return;
 
-	if (BUF_REFCNT(bp) < 1) {
+	if (!BUF_ISLOCKED(bp)) {
 		if (vfs_badlock_print)
 			printf(
 			    "VOP_STRATEGY: bp is not locked but should be\n");
--- //depot/vendor/freebsd/src/sys/nfs4client/nfs4_vnops.c	2008/01/13 14:45:30
+++ //depot/user/attilio/attilio_schedlock/nfs4client/nfs4_vnops.c	2008/01/18 23:33:23
@@ -2446,8 +2446,9 @@
 	struct ucred *cr;
 	int error = 0;
 
-	KASSERT(!(bp->b_flags & B_DONE), ("nfs4_strategy: buffer %p unexpectedly marked B_DONE", bp));
-	KASSERT(BUF_REFCNT(bp) > 0, ("nfs4_strategy: buffer %p not locked", bp));
+	KASSERT(!(bp->b_flags & B_DONE),
+	    ("nfs4_strategy: buffer %p unexpectedly marked B_DONE", bp));
+	KASSERT(BUF_ISLOCKED(bp), ("nfs4_strategy: buffer %p not locked", bp));
 
 	if (bp->b_iocmd == BIO_READ)
 		cr = bp->b_rcred;
@@ -2525,7 +2526,7 @@
 		bveccount = 0;
 		VI_LOCK(vp);
 		TAILQ_FOREACH_SAFE(bp, &vp->v_bufobj.bo_dirty.bv_hd, b_bobufs, nbp) {
-			if (BUF_REFCNT(bp) == 0 &&
+			if (!BUF_ISLOCKED(bp) &&
 			    (bp->b_flags & (B_DELWRI | B_NEEDCOMMIT))
 				== (B_DELWRI | B_NEEDCOMMIT))
 				bveccount++;
@@ -2807,7 +2808,7 @@
 	off_t off;
 #endif
 
-	if (BUF_REFCNT(bp) == 0)
+	if (!BUF_ISLOCKED(bp))
 		panic("bwrite: buffer is not locked???");
 
 	if (bp->b_flags & B_INVAL) {
--- //depot/vendor/freebsd/src/sys/nfsclient/nfs_subs.c	2008/01/13 14:45:30
+++ //depot/user/attilio/attilio_schedlock/nfsclient/nfs_subs.c	2008/01/18 23:33:23
@@ -918,7 +918,7 @@
 		}
 		MNT_IUNLOCK(mp);
 		TAILQ_FOREACH_SAFE(bp, &vp->v_bufobj.bo_dirty.bv_hd, b_bobufs, nbp) {
-			if (BUF_REFCNT(bp) == 0 &&
+			if (!BUF_ISLOCKED(bp) &&
 			    (bp->b_flags & (B_DELWRI | B_NEEDCOMMIT))
 				== (B_DELWRI | B_NEEDCOMMIT))
 				bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
--- //depot/vendor/freebsd/src/sys/nfsclient/nfs_vnops.c	2008/01/13 14:45:30
+++ //depot/user/attilio/attilio_schedlock/nfsclient/nfs_vnops.c	2008/01/18 23:33:23
@@ -2692,8 +2692,9 @@
 	struct buf *bp = ap->a_bp;
 	struct ucred *cr;
 
-	KASSERT(!(bp->b_flags & B_DONE), ("nfs_strategy: buffer %p unexpectedly marked B_DONE", bp));
-	KASSERT(BUF_REFCNT(bp) > 0, ("nfs_strategy: buffer %p not locked", bp));
+	KASSERT(!(bp->b_flags & B_DONE),
+	    ("nfs_strategy: buffer %p unexpectedly marked B_DONE", bp));
+	KASSERT(BUF_ISLOCKED(bp), ("nfs_strategy: buffer %p not locked", bp));
 
 	if (bp->b_iocmd == BIO_READ)
 		cr = bp->b_rcred;
@@ -2771,7 +2772,7 @@
 		bveccount = 0;
 		VI_LOCK(vp);
 		TAILQ_FOREACH_SAFE(bp, &vp->v_bufobj.bo_dirty.bv_hd, b_bobufs, nbp) {
-			if (BUF_REFCNT(bp) == 0 &&
+			if (!BUF_ISLOCKED(bp) &&
 			    (bp->b_flags & (B_DELWRI | B_NEEDCOMMIT))
 				== (B_DELWRI | B_NEEDCOMMIT))
 				bveccount++;
@@ -3087,7 +3088,7 @@
 	off_t off;
 #endif
 
-	if (BUF_REFCNT(bp) == 0)
+	if (!BUF_ISLOCKED(bp))
 		panic("bwrite: buffer is not locked???");
 
 	if (bp->b_flags & B_INVAL) {
--- //depot/vendor/freebsd/src/sys/sys/buf.h	2008/01/08 23:51:30
+++ //depot/user/attilio/attilio_schedlock/sys/buf.h	2008/01/19 00:21:37
@@ -320,11 +320,22 @@
 }
 
 /*
+ * Check if a buffer lock is recursed.
+ */
+#define	BUF_LOCKRECURSED(bp)						\
+	(lockmgr_recursed(&(bp)->b_lock))
+
+/*
+ * Check if a buffer lock is currently held.
+ */
+#define	BUF_ISLOCKED(bp)						\
+	(lockstatus(&(bp)->b_lock, curthread))
+/*
  * Free a buffer lock.
  */
 #define BUF_LOCKFREE(bp) 			\
 do {						\
-	if (BUF_REFCNT(bp) > 0)			\
+	if (BUF_ISLOCKED(bp))			\
 		panic("free locked buf");	\
 	lockdestroy(&(bp)->b_lock);		\
 } while (0)
@@ -344,29 +355,6 @@
 	lockmgr_disown(&bp->b_lock);
 }
 #endif
-/*
- * Find out the number of references to a lock.
- */
-static __inline int BUF_REFCNT(struct buf *);
-static __inline int
-BUF_REFCNT(struct buf *bp)
-{
-	int s, ret;
-
-	/*
-	 * When the system is panicing, the lock manager grants all lock
-	 * requests whether or not the lock is available. To avoid "unlocked
-	 * buffer" panics after a crash, we just claim that all buffers
-	 * are locked when cleaning up after a system panic.
-	 */
-	if (panicstr != NULL)
-		return (1);
-	s = splbio();
-	ret = lockcount(&(bp)->b_lock);
-	splx(s);
-	return ret;
-}
-
 
 /*
  * Find out the number of waiters on a lock.
--- //depot/vendor/freebsd/src/sys/sys/lockmgr.h	2008/01/08 23:51:30
+++ //depot/user/attilio/attilio_schedlock/sys/lockmgr.h	2008/01/18 22:14:37
@@ -204,6 +204,8 @@
 int	lockwaiters(struct lock *);
 
 #define lockmgr(lock, flags, mtx, td) _lockmgr((lock), (flags), (mtx), (td), __FILE__, __LINE__)
+#define	lockmgr_recursed(lkp)						\
+	((lkp)->lk_exclusivecount > 1)
 #ifdef DDB
 int	lockmgr_chain(struct thread *td, struct thread **ownerp);
 #endif
--- //depot/vendor/freebsd/src/sys/ufs/ffs/ffs_vfsops.c	2008/01/13 14:45:30
+++ //depot/user/attilio/attilio_schedlock/ufs/ffs/ffs_vfsops.c	2008/01/18 23:33:23
@@ -1718,7 +1718,7 @@
 
 	oldflags = bp->b_flags;
 
-	if (BUF_REFCNT(bp) == 0)
+	if (!BUF_ISLOCKED(bp))
 		panic("bufwrite: buffer is not busy???");
 	s = splbio();
 	/*