diff --git a/sys/ufs/ffs/ffs_alloc.c b/sys/ufs/ffs/ffs_alloc.c
index 827af171d8b9..a746a69a2de5 100644
--- a/sys/ufs/ffs/ffs_alloc.c
+++ b/sys/ufs/ffs/ffs_alloc.c
@@ -188,6 +188,7 @@ ffs_alloc(ip, lbn, bpref, size, cred, bnp)
 		*bnp = bno;
 		return (0);
 	}
+nospace:
 #ifdef QUOTA
 	UFS_UNLOCK(ump);
 	/*
@@ -196,7 +197,6 @@ ffs_alloc(ip, lbn, bpref, size, cred, bnp)
 	(void) chkdq(ip, -btodb(size), cred, FORCE);
 	UFS_LOCK(ump);
 #endif
-nospace:
 	if (fs->fs_pendingblocks > 0 && reclaimed == 0) {
 		reclaimed = 1;
 		softdep_request_cleanup(fs, ITOV(ip));
diff --git a/sys/ufs/ffs/ffs_snapshot.c b/sys/ufs/ffs/ffs_snapshot.c
index 6ab9af25bcde..14b231cda6eb 100644
--- a/sys/ufs/ffs/ffs_snapshot.c
+++ b/sys/ufs/ffs/ffs_snapshot.c
@@ -281,6 +281,7 @@ ffs_snapshot(mp, snapfile)
 		return (error);
 	}
 	vp = nd.ni_vp;
+	vp->v_vflag |= VV_SYSTEM;
 	ip = VTOI(vp);
 	devvp = ip->i_devvp;
 	/*
@@ -367,18 +368,6 @@ ffs_snapshot(mp, snapfile)
 		if (error)
 			goto out;
 	}
-#ifdef QUOTA
-	/*
-	 * Turn off disk quotas for snapshot file.
-	 */
-	(void) chkdq(ip, -DIP(ip, i_blocks), KERNCRED, FORCE);
-	for (i = 0; i < MAXQUOTAS; i++) {
-		if (ip->i_dquot[i] != NODQUOT) {
-			dqrele(vp, ip->i_dquot[i]);
-			ip->i_dquot[i] = NODQUOT;
-		}
-	}
-#endif
 	/*
 	 * Change inode to snapshot type file.
 	 */
@@ -682,7 +671,6 @@ ffs_snapshot(mp, snapfile)
 	devvp->v_vflag |= VV_COPYONWRITE;
 	VI_UNLOCK(devvp);
 	ASSERT_VOP_LOCKED(vp, "ffs_snapshot vp");
-	vp->v_vflag |= VV_SYSTEM;
 out1:
 	KASSERT((sn != NULL && sbp != NULL && error == 0) ||
 		(sn == NULL && sbp == NULL && error != 0),
diff --git a/sys/ufs/ufs/quota.h b/sys/ufs/ufs/quota.h
index 8fb9eb267c18..a42493e8f17e 100644
--- a/sys/ufs/ufs/quota.h
+++ b/sys/ufs/ufs/quota.h
@@ -174,7 +174,7 @@ struct ucred;
 struct vnode;
 
 int	chkdq(struct inode *, int64_t, struct ucred *, int);
-int	chkiq(struct inode *, ino_t, struct ucred *, int);
+int	chkiq(struct inode *, int, struct ucred *, int);
 void	dqinit(void);
 void	dqrele(struct vnode *, struct dquot *);
 void	dquninit(void);
diff --git a/sys/ufs/ufs/ufs_quota.c b/sys/ufs/ufs/ufs_quota.c
index c4a93cdbfb7f..a3f426bc7902 100644
--- a/sys/ufs/ufs/ufs_quota.c
+++ b/sys/ufs/ufs/ufs_quota.c
@@ -72,7 +72,7 @@ static MALLOC_DEFINE(M_DQUOT, "ufs_quota", "UFS quota entries");
 static char *quotatypes[] = INITQFNAMES;
 
 static int chkdqchg(struct inode *, ufs2_daddr_t, struct ucred *, int);
-static int chkiqchg(struct inode *, ino_t, struct ucred *, int);
+static int chkiqchg(struct inode *, int, struct ucred *, int);
 static int dqget(struct vnode *,
 		u_long, struct ufsmount *, int, struct dquot **);
 static int dqsync(struct vnode *, struct dquot *);
@@ -99,13 +99,18 @@ getinoquota(ip)
 	struct vnode *vp = ITOV(ip);
 	int error;
 
-#ifndef NO_FFS_SNAPSHOT
 	/*
-	 * Disk quotas must be turned off for snapshot files.
+	 * Disk quotas must be turned off for system files.  Currently
+	 * snapshot and quota files.
 	 */
-	if ((ip->i_flags & SF_SNAPSHOT) != 0)
+	if ((vp->v_vflag & VV_SYSTEM) != 0)
+		return (0);
+	/*
+	 * XXX: Turn off quotas for files with a negative UID or GID.
+	 * This prevents the creation of 100GB+ quota files.
+	 */
+	if ((int)ip->i_uid < 0 || (int)ip->i_gid < 0)
 		return (0);
-#endif
 	ump = VFSTOUFS(vp->v_mount);
 	/*
 	 * Set up the user quota based on file uid.
@@ -140,8 +145,21 @@ chkdq(ip, change, cred, flags)
 {
 	struct dquot *dq;
 	ufs2_daddr_t ncurblocks;
+	struct vnode *vp = ITOV(ip);
 	int i, error;
 
+	/*
+	 * Disk quotas must be turned off for system files.  Currently
+	 * snapshot and quota files.
+	 */
+	if ((vp->v_vflag & VV_SYSTEM) != 0)
+		return (0);
+	/*
+	 * XXX: Turn off quotas for files with a negative UID or GID.
+	 * This prevents the creation of 100GB+ quota files.
+	 */
+	if ((int)ip->i_uid < 0 || (int)ip->i_gid < 0)
+		return (0);
 #ifdef DIAGNOSTIC
 	if ((flags & CHOWN) == 0)
 		chkdquot(ip);
@@ -256,7 +274,7 @@ chkdqchg(ip, change, cred, type)
 int
 chkiq(ip, change, cred, flags)
 	struct inode *ip;
-	ino_t change;
+	int change;
 	struct ucred *cred;
 	int flags;
 {
@@ -270,7 +288,6 @@ chkiq(ip, change, cred, flags)
 #endif
 	if (change == 0)
 		return (0);
-	/* XXX: change is unsigned */
 	if (change < 0) {
 		for (i = 0; i < MAXQUOTAS; i++) {
 			if ((dq = ip->i_dquot[i]) == NODQUOT)
@@ -281,7 +298,7 @@ chkiq(ip, change, cred, flags)
 			}
 			ncurinodes = dq->dq_curinodes + change;
 			/* XXX: ncurinodes is unsigned */
-			if (ncurinodes >= 0)
+			if (dq->dq_curinodes != 0 && ncurinodes >= 0)
 				dq->dq_curinodes = ncurinodes;
 			else
 				dq->dq_curinodes = 0;
@@ -325,7 +342,7 @@ chkiq(ip, change, cred, flags)
 static int
 chkiqchg(ip, change, cred, type)
 	struct inode *ip;
-	ino_t change;
+	int change;
 	struct ucred *cred;
 	int type;
 {
@@ -384,15 +401,21 @@ chkdquot(ip)
 	struct inode *ip;
 {
 	struct ufsmount *ump = VFSTOUFS(ITOV(ip)->v_mount);
+	struct vnode *vp = ITOV(ip);
 	int i;
 
-#ifndef NO_FFS_SNAPSHOT
 	/*
-	 * Disk quotas must be turned off for snapshot files.
+	 * Disk quotas must be turned off for system files.  Currently
+	 * these are snapshots and quota files.
 	 */
-	if ((ip->i_flags & SF_SNAPSHOT) != 0)
+	if ((vp->v_vflag & VV_SYSTEM) != 0)
 		return;
-#endif
+	/*
+	 * XXX: Turn off quotas for files with a negative UID or GID.
+	 * This prevents the creation of 100GB+ quota files.
+	 */
+	if ((int)ip->i_uid < 0 || (int)ip->i_gid < 0)
+		return (0);
 	for (i = 0; i < MAXQUOTAS; i++) {
 		if (ump->um_quotas[i] == NULLVP ||
 		    (ump->um_qflags[i] & (QTF_OPENING|QTF_CLOSING)))
@@ -929,7 +952,7 @@ dqget(vp, id, ump, type, dqp)
 	aiov.iov_base = &dq->dq_dqb;
 	aiov.iov_len = sizeof (struct dqblk);
 	auio.uio_resid = sizeof (struct dqblk);
-	auio.uio_offset = (off_t)(id * sizeof (struct dqblk));
+	auio.uio_offset = (off_t)id * sizeof (struct dqblk);
 	auio.uio_segflg = UIO_SYSSPACE;
 	auio.uio_rw = UIO_READ;
 	auio.uio_td = (struct thread *)0;
@@ -1044,7 +1067,7 @@ dqsync(vp, dq)
 	aiov.iov_base = &dq->dq_dqb;
 	aiov.iov_len = sizeof (struct dqblk);
 	auio.uio_resid = sizeof (struct dqblk);
-	auio.uio_offset = (off_t)(dq->dq_id * sizeof (struct dqblk));
+	auio.uio_offset = (off_t)dq->dq_id * sizeof (struct dqblk);
 	auio.uio_segflg = UIO_SYSSPACE;
 	auio.uio_rw = UIO_WRITE;
 	auio.uio_td = (struct thread *)0;