svn commit: r232285 - stable/9/sys/ufs/ufs

[Konstantin Belousov]

Author: kib
Date: Wed Feb 29 01:39:39 2012
New Revision: 232285
URL: http://svn.freebsd.org/changeset/base/232285

Log:
  MFC r232003:
  Properly lock DQREF() with dqhlock. Missed locking caused counter
  corruption.
  
  Assert that the dq reference value is sane before decrementing it.

Modified:
  stable/9/sys/ufs/ufs/ufs_quota.c
Directory Properties:
  stable/9/sys/   (props changed)

Modified: stable/9/sys/ufs/ufs/ufs_quota.c
==============================================================================
--- stable/9/sys/ufs/ufs/ufs_quota.c	Wed Feb 29 01:38:36 2012	(r232284)
+++ stable/9/sys/ufs/ufs/ufs_quota.c	Wed Feb 29 01:39:39 2012	(r232285)
@@ -1469,6 +1469,7 @@ dqrele(struct vnode *vp, struct dquot *d
 	if (dq == NODQUOT)
 		return;
 	DQH_LOCK();
+	KASSERT(dq->dq_cnt > 0, ("Lost dq %p reference 1", dq));
 	if (dq->dq_cnt > 1) {
 		dq->dq_cnt--;
 		DQH_UNLOCK();
@@ -1479,6 +1480,7 @@ sync:
 	(void) dqsync(vp, dq);
 
 	DQH_LOCK();
+	KASSERT(dq->dq_cnt > 0, ("Lost dq %p reference 2", dq));
 	if (--dq->dq_cnt > 0)
 	{
 		DQH_UNLOCK();
@@ -1658,6 +1660,7 @@ quotaref(vp, qrp)
 	 */
 	found = 0;
 	ip = VTOI(vp);
+	mtx_lock(&dqhlock);
 	for (i = 0; i < MAXQUOTAS; i++) {
 		if ((dq = ip->i_dquot[i]) == NODQUOT)
 			continue;
@@ -1665,6 +1668,7 @@ quotaref(vp, qrp)
 		qrp[i] = dq;
 		found++;
 	}
+	mtx_unlock(&dqhlock);
 	return (found);
 }