dynamic allocation of vnodes

[unix-history] / usr / src / sys / kern / vfs_subr.c

diff --git a/usr/src/sys/kern/vfs_subr.c b/usr/src/sys/kern/vfs_subr.c
index ee6b9ee..4720466 100644 (file)
--- a/usr/src/sys/kern/vfs_subr.c
+++ b/usr/src/sys/kern/vfs_subr.c
@@ -14,7 +14,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *

- *     @(#)vfs_subr.c  7.35 (Berkeley) %G%
+ *     @(#)vfs_subr.c  7.38 (Berkeley) %G%

  */
 
 /*
  */
 
 /*


@@ -171,32 +171,15 @@ ndrele(ndp)
 struct vnode *vfreeh, **vfreet;
 extern struct vnodeops dead_vnodeops, spec_vnodeops;
 extern void vclean();
 struct vnode *vfreeh, **vfreet;
 extern struct vnodeops dead_vnodeops, spec_vnodeops;
 extern void vclean();

+long numvnodes;

 
 /*
  * Initialize the vnode structures and initialize each file system type.
  */
 vfsinit()
 {
 
 /*
  * Initialize the vnode structures and initialize each file system type.
  */
 vfsinit()
 {

-       register struct vnode *vp = vnode;

        struct vfsops **vfsp;
 
        struct vfsops **vfsp;
 

-       /*
-        * Build vnode free list.
-        */
-       vfreeh = vp;
-       vfreet = &vp->v_freef;
-       vp->v_freeb = &vfreeh;
-       vp->v_op = &dead_vnodeops;
-       vp->v_type = VBAD;
-       for (vp++; vp < vnodeNVNODE; vp++) {
-               *vfreet = vp;
-               vp->v_freeb = vfreet;
-               vfreet = &vp->v_freef;
-               vp->v_op = &dead_vnodeops;
-               vp->v_type = VBAD;
-       }
-       vp--;
-       vp->v_freef = NULL;

        /*
         * Initialize the vnode name cache
         */
        /*
         * Initialize the vnode name cache
         */


@@ -222,26 +205,34 @@ getnewvnode(tag, mp, vops, vpp)
 {
        register struct vnode *vp, *vq;
 
 {
        register struct vnode *vp, *vq;
 

-       if ((vp = vfreeh) == NULL) {
-               tablefull("vnode");
-               *vpp = 0;
-               return (ENFILE);
+       if (numvnodes < desiredvnodes) {
+               vp = (struct vnode *)malloc(sizeof *vp, M_VNODE, M_WAITOK);
+               bzero((char *)vp, sizeof *vp);
+               numvnodes++;
+       } else {
+               if ((vp = vfreeh) == NULL) {
+                       tablefull("vnode");
+                       *vpp = 0;
+                       return (ENFILE);
+               }
+               if (vp->v_usecount)
+                       panic("free vnode isn't");
+               if (vq = vp->v_freef)
+                       vq->v_freeb = &vfreeh;
+               else
+                       vfreet = &vfreeh;
+               vfreeh = vq;
+               vp->v_freef = NULL;
+               vp->v_freeb = NULL;
+               if (vp->v_type != VBAD)
+                       vgone(vp);
+               vp->v_flag = 0;
+               vp->v_shlockc = 0;
+               vp->v_exlockc = 0;
+               vp->v_lastr = 0;
+               vp->v_socket = 0;

        }
        }

-       if (vp->v_usecount)
-               panic("free vnode isn't");
-       if (vq = vp->v_freef)
-               vq->v_freeb = &vfreeh;
-       vfreeh = vq;
-       vp->v_freef = NULL;
-       vp->v_freeb = NULL;
-       if (vp->v_type != VBAD)
-               vgone(vp);

        vp->v_type = VNON;
        vp->v_type = VNON;

-       vp->v_flag = 0;
-       vp->v_shlockc = 0;
-       vp->v_exlockc = 0;
-       vp->v_lastr = 0;
-       vp->v_socket = 0;

        cache_purge(vp);
        vp->v_tag = tag;
        vp->v_op = vops;
        cache_purge(vp);
        vp->v_tag = tag;
        vp->v_op = vops;


@@ -618,14 +609,36 @@ void vgoneall(vp)
 {
        register struct vnode *vq;
 
 {
        register struct vnode *vq;
 

-       while (vp->v_flag & VALIASED) {
-               for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
-                       if (vq->v_rdev != vp->v_rdev ||
-                           vq->v_type != vp->v_type || vp == vq)
-                               continue;
-                       vgone(vq);
-                       break;
+       if (vp->v_flag & VALIASED) {
+               /*
+                * If a vgone (or vclean) is already in progress,
+                * wait until it is done and return.
+                */
+               if (vp->v_flag & VXLOCK) {
+                       vp->v_flag |= VXWANT;
+                       sleep((caddr_t)vp, PINOD);
+                       return;

                }
                }

+               /*
+                * Ensure that vp will not be vgone'd while we
+                * are eliminating its aliases.
+                */
+               vp->v_flag |= VXLOCK;
+               while (vp->v_flag & VALIASED) {
+                       for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
+                               if (vq->v_rdev != vp->v_rdev ||
+                                   vq->v_type != vp->v_type || vp == vq)
+                                       continue;
+                               vgone(vq);
+                               break;
+                       }
+               }
+               /*
+                * Remove the lock so that vgone below will
+                * really eliminate the vnode after which time
+                * vgone will awaken any sleepers.
+                */
+               vp->v_flag &= ~VXLOCK;

        }
        vgone(vp);
 }
        }
        vgone(vp);
 }