fix readdir for no-linear stacks

[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 0da28d4..68e2bc8 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        8.15 (Berkeley) %G%
+ *     @(#)union_subr.c        8.16 (Berkeley) %G%

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


@@ -239,7 +239,7 @@ union_newsize(vp, uppersz, lowersz)
  * the vnode free list.
  */
 int
  * the vnode free list.
  */
 int

-union_allocvp(vpp, mp, undvp, dvp, cnp, uppervp, lowervp)
+union_allocvp(vpp, mp, undvp, dvp, cnp, uppervp, lowervp, docache)

        struct vnode **vpp;
        struct mount *mp;
        struct vnode *undvp;            /* parent union vnode */
        struct vnode **vpp;
        struct mount *mp;
        struct vnode *undvp;            /* parent union vnode */


@@ -247,6 +247,7 @@ union_allocvp(vpp, mp, undvp, dvp, cnp, uppervp, lowervp)
        struct componentname *cnp;      /* may be null */
        struct vnode *uppervp;          /* may be null */
        struct vnode *lowervp;          /* may be null */
        struct componentname *cnp;      /* may be null */
        struct vnode *uppervp;          /* may be null */
        struct vnode *lowervp;          /* may be null */

+       int docache;

 {
        int error;
        struct union_node *un;
 {
        int error;
        struct union_node *un;


@@ -278,7 +279,9 @@ union_allocvp(vpp, mp, undvp, dvp, cnp, uppervp, lowervp)
        }
 
 loop:
        }
 
 loop:

-       for (try = 0; try < 3; try++) {
+       if (!docache) {
+               un = 0;
+       } else for (try = 0; try < 3; try++) {

                switch (try) {
                case 0:
                        if (lowervp == NULLVP)
                switch (try) {
                case 0:
                        if (lowervp == NULLVP)


@@ -409,14 +412,16 @@ loop:
                return (0);
        }
 
                return (0);
        }
 

-       /*
-        * otherwise lock the vp list while we call getnewvnode
-        * since that can block.
-        */ 
-       hash = UNION_HASH(uppervp, lowervp);
+       if (docache) {
+               /*
+                * otherwise lock the vp list while we call getnewvnode
+                * since that can block.
+                */ 
+               hash = UNION_HASH(uppervp, lowervp);

 
 

-       if (union_list_lock(hash))
-               goto loop;
+               if (union_list_lock(hash))
+                       goto loop;
+       }

 
        error = getnewvnode(VT_UNION, mp, union_vnodeop_p, vpp);
        if (error) {
 
        error = getnewvnode(VT_UNION, mp, union_vnodeop_p, vpp);
        if (error) {


@@ -449,6 +454,7 @@ loop:
        un->un_pvp = undvp;
        if (undvp != NULLVP)
                VREF(undvp);
        un->un_pvp = undvp;
        if (undvp != NULLVP)
                VREF(undvp);

+       un->un_dircache = 0;

        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)


@@ -472,14 +478,17 @@ loop:
                un->un_dirvp = 0;
        }
 
                un->un_dirvp = 0;
        }
 

-       LIST_INSERT_HEAD(&unhead[hash], un, un_cache);
-       un->un_flags |= UN_CACHED;
+       if (docache) {
+               LIST_INSERT_HEAD(&unhead[hash], un, un_cache);
+               un->un_flags |= UN_CACHED;
+       }

 
        if (xlowervp)
                vrele(xlowervp);
 
 out:
 
        if (xlowervp)
                vrele(xlowervp);
 
 out:

-       union_list_unlock(hash);
+       if (docache)
+               union_list_unlock(hash);

 
        return (error);
 }
 
        return (error);
 }


@@ -923,6 +932,7 @@ union_removed_upper(un)
        }
 }
 
        }
 }
 

+#if 0

 struct vnode *
 union_lowervp(vp)
        struct vnode *vp;
 struct vnode *
 union_lowervp(vp)
        struct vnode *vp;


@@ -937,6 +947,7 @@ union_lowervp(vp)
 
        return (NULLVP);
 }
 
        return (NULLVP);
 }

+#endif

 
 /*
  * determine whether a whiteout is needed
 
 /*
  * determine whether a whiteout is needed


@@ -959,3 +970,76 @@ union_dowhiteout(un, cred, p)
 
        return (0);
 }
 
        return (0);
 }

+
+static void
+union_dircache_r(vp, vppp, cntp)
+       struct vnode *vp;
+       struct vnode ***vppp;
+       int *cntp;
+{
+       struct union_node *un;
+
+       if (vp->v_op != union_vnodeop_p) {
+               if (vppp) {
+                       VREF(vp);
+                       *(*vppp)++ = vp;
+                       if (--(*cntp) == 0)
+                               panic("union: dircache table too small");
+               } else {
+                       (*cntp)++;
+               }
+
+               return;
+       }
+
+       un = VTOUNION(vp);
+       if (un->un_uppervp != NULLVP)
+               union_dircache_r(un->un_uppervp, vppp, cntp);
+       if (un->un_lowervp != NULLVP)
+               union_dircache_r(un->un_lowervp, vppp, cntp);
+}
+
+struct vnode *
+union_dircache(vp)
+       struct vnode *vp;
+{
+       int cnt;
+       struct vnode *nvp;
+       struct vnode **vpp;
+       struct vnode **dircache = VTOUNION(vp)->un_dircache;
+       struct union_node *un;
+       int error;
+
+       if (dircache == 0) {
+               cnt = 0;
+               union_dircache_r(vp, 0, &cnt);
+               cnt++;
+               dircache = (struct vnode **)
+                               malloc(cnt * sizeof(struct vnode *),
+                                       M_TEMP, M_WAITOK);
+               vpp = dircache;
+               union_dircache_r(vp, &vpp, &cnt);
+               *vpp = NULLVP;
+               vpp = dircache + 1;
+       } else {
+               vpp = dircache;
+               do {
+                       if (*vpp++ == VTOUNION(vp)->un_uppervp)
+                               break;
+               } while (*vpp != NULLVP);
+       }
+
+       if (*vpp == NULLVP)
+               return (NULLVP);
+
+       VOP_LOCK(*vpp);
+       VREF(*vpp);
+       error = union_allocvp(&nvp, vp->v_mount, NULLVP, NULLVP, 0, *vpp, NULLVP, 0);
+       if (error)
+               return (NULLVP);
+       VTOUNION(vp)->un_dircache = 0;
+       un = VTOUNION(nvp);
+       un->un_dircache = dircache;
+
+       return (nvp);
+}