xnu-201.tar.gz

[apple/xnu.git] / bsd / miscfs / specfs / spec_vnops.c

diff --git a/bsd/miscfs/specfs/spec_vnops.c b/bsd/miscfs/specfs/spec_vnops.c
index 5391c20aacaad1ec8fe3b588422dc6d583eed749..86dba15885b5c776c0fb31aeb8bd5e12260d6c37 100644 (file)
--- a/bsd/miscfs/specfs/spec_vnops.c
+++ b/bsd/miscfs/specfs/spec_vnops.c
@@ -511,6 +511,7 @@ spec_select(ap)
                int  a_which;
                int  a_fflags;
                struct ucred *a_cred;
+               void * a_wql;
                struct proc *a_p;
        } */ *ap;
 {
@@ -523,7 +524,7 @@ spec_select(ap)
 
        case VCHR:
                dev = ap->a_vp->v_rdev;
-               return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_p);
+               return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_wql, ap->a_p);
        }
 }
 /*
@@ -677,12 +678,16 @@ spec_close(ap)
                break;
 
        case VBLK:
+#ifdef DEVFS_IMPLEMENTS_LOCKING
                /*
                 * On last close of a block device (that isn't mounted)
                 * we must invalidate any in core blocks, so that
                 * we can, for instance, change floppy disks.
                 */
-               if (error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0))
+               vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_p);
+               error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0);
+               VOP_UNLOCK(vp, 0, ap->a_p);
+               if (error)
                        return (error);
                /*
                 * We do not want to really close the device if it
@@ -695,6 +700,28 @@ spec_close(ap)
                 */
                if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0)
                        return (0);
+#else /* DEVFS_IMPLEMENTS_LOCKING */
+               /*
+                * We do not want to really close the device if it
+                * is still in use unless we are trying to close it
+                * forcibly. Since every use (buffer, vnode, swap, cmap)
+                * holds a reference to the vnode, and because we mark
+                * any other vnodes that alias this device, when the
+                * sum of the reference counts on all the aliased
+                * vnodes descends to one, we are on last close.
+                */
+               if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0)
+                       return (0);
+
+               /*
+                * On last close of a block device (that isn't mounted)
+                * we must invalidate any in core blocks, so that
+                * we can, for instance, change floppy disks.
+                */
+               error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0);
+               if (error)
+                       return (error);
+#endif /* DEVFS_IMPLEMENTS_LOCKING */
                devclose = bdevsw[major(dev)].d_close;
                mode = S_IFBLK;
                break;