diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index a2c723b..34bdf59 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1202,26 +1202,32 @@
 	case S_IFREG:
 	case S_IFDIR:
 		if (unlikely(pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
-			if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT) {
-				if ((mode & S_IFMT) == S_IFDIR) {
-					ip->i_d.di_flags |= XFS_DIFLAG_RTINHERIT;
-				} else {
-					ip->i_d.di_flags |= XFS_DIFLAG_REALTIME;
+			uint	di_flags = 0;
+
+			if ((mode & S_IFMT) == S_IFDIR) {
+				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
+					di_flags |= XFS_DIFLAG_RTINHERIT;
+			} else {
+				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT) {
+					di_flags |= XFS_DIFLAG_REALTIME;
 					ip->i_iocore.io_flags |= XFS_IOCORE_RT;
 				}
 			}
 			if ((pip->i_d.di_flags & XFS_DIFLAG_NOATIME) &&
 			    xfs_inherit_noatime)
-				ip->i_d.di_flags |= XFS_DIFLAG_NOATIME;
+				di_flags |= XFS_DIFLAG_NOATIME;
 			if ((pip->i_d.di_flags & XFS_DIFLAG_NODUMP) &&
 			    xfs_inherit_nodump)
-				ip->i_d.di_flags |= XFS_DIFLAG_NODUMP;
+				di_flags |= XFS_DIFLAG_NODUMP;
 			if ((pip->i_d.di_flags & XFS_DIFLAG_SYNC) &&
 			    xfs_inherit_sync)
-				ip->i_d.di_flags |= XFS_DIFLAG_SYNC;
+				di_flags |= XFS_DIFLAG_SYNC;
 			if ((pip->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) &&
 			    xfs_inherit_nosymlinks)
-				ip->i_d.di_flags |= XFS_DIFLAG_NOSYMLINKS;
+				di_flags |= XFS_DIFLAG_NOSYMLINKS;
+			if (pip->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
+				di_flags |= XFS_DIFLAG_PROJINHERIT;
+			ip->i_d.di_flags |= di_flags;
 		}
 		/* FALLTHROUGH */
 	case S_IFLNK:
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 695978b..96dc18b 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -507,8 +507,6 @@
 		 * that the group ID supplied to the chown() function
 		 * shall be equal to either the group ID or one of the
 		 * supplementary group IDs of the calling process.
-		 *
-		 * XXX: How does restricted_chown affect projid?
 		 */
 		if (restricted_chown &&
 		    (iuid != uid || (igid != gid &&
@@ -860,6 +858,8 @@
 				di_flags |= XFS_DIFLAG_NOATIME;
 			if (vap->va_xflags & XFS_XFLAG_NODUMP)
 				di_flags |= XFS_DIFLAG_NODUMP;
+			if (vap->va_xflags & XFS_XFLAG_PROJINHERIT)
+				di_flags |= XFS_DIFLAG_PROJINHERIT;
 			if ((ip->i_d.di_mode & S_IFMT) == S_IFDIR) {
 				if (vap->va_xflags & XFS_XFLAG_RTINHERIT)
 					di_flags |= XFS_DIFLAG_RTINHERIT;
@@ -1915,7 +1915,9 @@
 	/* Return through std_return after this point. */
 
 	udqp = gdqp = NULL;
-	if (vap->va_mask & XFS_AT_PROJID)
+	if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
+		prid = dp->i_d.di_projid;
+	else if (vap->va_mask & XFS_AT_PROJID)
 		prid = (xfs_prid_t)vap->va_projid;
 	else
 		prid = (xfs_prid_t)dfltprid;
@@ -2621,17 +2623,7 @@
 	if (src_vp->v_type == VDIR)
 		return XFS_ERROR(EPERM);
 
-	/*
-	 * For now, manually find the XFS behavior descriptor for
-	 * the source vnode.  If it doesn't exist then something
-	 * is wrong and we should just return an error.
-	 * Eventually we need to figure out how link is going to
-	 * work in the face of stacked vnodes.
-	 */
 	src_bdp = vn_bhv_lookup_unlocked(VN_BHV_HEAD(src_vp), &xfs_vnodeops);
-	if (src_bdp == NULL) {
-		return XFS_ERROR(EXDEV);
-	}
 	sip = XFS_BHVTOI(src_bdp);
 	tdp = XFS_BHVTOI(target_dir_bdp);
 	mp = tdp->i_mount;
@@ -2698,6 +2690,17 @@
 		goto error_return;
 	}
 
+	/*
+	 * If we are using project inheritance, we only allow hard link
+	 * creation in our tree when the project IDs are the same; else
+	 * the tree quota mechanism could be circumvented.
+	 */
+	if (unlikely((tdp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
+		     (tdp->i_d.di_projid != sip->i_d.di_projid))) {
+		error = XFS_ERROR(EPERM);
+		goto error_return;
+	}
+
 	if (resblks == 0 &&
 	    (error = XFS_DIR_CANENTER(mp, tp, tdp, target_name,
 			target_namelen)))
@@ -2820,7 +2823,9 @@
 
 	mp = dp->i_mount;
 	udqp = gdqp = NULL;
-	if (vap->va_mask & XFS_AT_PROJID)
+	if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
+		prid = dp->i_d.di_projid;
+	else if (vap->va_mask & XFS_AT_PROJID)
 		prid = (xfs_prid_t)vap->va_projid;
 	else
 		prid = (xfs_prid_t)dfltprid;
@@ -3374,7 +3379,9 @@
 	/* Return through std_return after this point. */
 
 	udqp = gdqp = NULL;
-	if (vap->va_mask & XFS_AT_PROJID)
+	if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
+		prid = dp->i_d.di_projid;
+	else if (vap->va_mask & XFS_AT_PROJID)
 		prid = (xfs_prid_t)vap->va_projid;
 	else
 		prid = (xfs_prid_t)dfltprid;