keep track of vnode size changes.

[unix-history] / usr / src / sys / miscfs / union / union_subr.c

diff --git a/usr/src/sys/miscfs/union/union_subr.c b/usr/src/sys/miscfs/union/union_subr.c
index 1149caa..f71072c 100644 (file)
--- a/usr/src/sys/miscfs/union/union_subr.c
+++ b/usr/src/sys/miscfs/union/union_subr.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)union_subr.c        8.6 (Berkeley) %G%
+ *     @(#)union_subr.c        8.7 (Berkeley) %G%

  */
 
 #include <sys/param.h>
  */
 
 #include <sys/param.h>


@@ -22,6 +22,7 @@
 #include <sys/filedesc.h>
 #include <sys/queue.h>
 #include <sys/mount.h>
 #include <sys/filedesc.h>
 #include <sys/queue.h>
 #include <sys/mount.h>

+#include <vm/vm.h>             /* for vnode_pager_setsize */

 #include <miscfs/union/union.h>
 
 #ifdef DIAGNOSTIC
 #include <miscfs/union/union.h>
 
 #ifdef DIAGNOSTIC


@@ -127,6 +128,7 @@ union_updatevp(un, uppervp, lowervp)
                        }
                }
                un->un_lowervp = lowervp;
                        }
                }
                un->un_lowervp = lowervp;

+               un->un_lowersz = VNOVAL;

        }
 
        if (un->un_uppervp != uppervp) {
        }
 
        if (un->un_uppervp != uppervp) {


@@ -134,6 +136,7 @@ union_updatevp(un, uppervp, lowervp)
                        vrele(un->un_uppervp);
 
                un->un_uppervp = uppervp;
                        vrele(un->un_uppervp);
 
                un->un_uppervp = uppervp;

+               un->un_uppersz = VNOVAL;

        }
 
        if (docache && (ohash != nhash)) {
        }
 
        if (docache && (ohash != nhash)) {


@@ -162,6 +165,47 @@ union_newupper(un, uppervp)
        union_updatevp(un, uppervp, un->un_lowervp);
 }
 
        union_updatevp(un, uppervp, un->un_lowervp);
 }
 

+/*
+ * Keep track of size changes in the underlying vnodes.
+ * If the size changes, then callback to the vm layer
+ * giving priority to the upper layer size.
+ */
+void
+union_newsize(vp, uppersz, lowersz)
+       struct vnode *vp;
+       off_t uppersz, lowersz;
+{
+       struct union_node *un;
+       off_t sz;
+
+       /* only interested in regular files */
+       if (vp->v_type != VREG)
+               return;
+
+       un = VTOUNION(vp);
+       sz = VNOVAL;
+
+       if ((uppersz != VNOVAL) && (un->un_uppersz != uppersz)) {
+               un->un_uppersz = uppersz;
+               if (sz == VNOVAL)
+                       sz = un->un_uppersz;
+       }
+
+       if ((lowersz != VNOVAL) && (un->un_lowersz != lowersz)) {
+               un->un_lowersz = lowersz;
+               if (sz == VNOVAL)
+                       sz = un->un_lowersz;
+       }
+
+       if (sz != VNOVAL) {
+#ifdef UNION_DIAGNOSTIC
+               printf("union: %s size now %ld\n",
+                       uppersz != VNOVAL ? "upper" : "lower", (long) sz);
+#endif
+               vnode_pager_setsize(vp, sz);
+       }
+}
+

 /*
  * allocate a union_node/vnode pair.  the vnode is
  * referenced and locked.  the new vnode is returned
 /*
  * allocate a union_node/vnode pair.  the vnode is
  * referenced and locked.  the new vnode is returned


@@ -398,7 +442,9 @@ loop:
        un = VTOUNION(*vpp);
        un->un_vnode = *vpp;
        un->un_uppervp = uppervp;
        un = VTOUNION(*vpp);
        un->un_vnode = *vpp;
        un->un_uppervp = uppervp;

+       un->un_uppersz = VNOVAL;

        un->un_lowervp = lowervp;
        un->un_lowervp = lowervp;

+       un->un_lowersz = VNOVAL;

        un->un_openl = 0;
        un->un_flags = UN_LOCKED;
        if (un->un_uppervp)
        un->un_openl = 0;
        un->un_flags = UN_LOCKED;
        if (un->un_uppervp)