+/*
+ * Grab a particular vnode from the free list, increment its
+ * reference count and lock it. The vnode lock bit is set the
+ * vnode is being eliminated in vgone. The process is awakened
+ * when the transition is completed, and an error returned to
+ * indicate that the vnode is no longer usable (possibly having
+ * been changed to a new file system type).
+ */
+vget(vp)
+ register struct vnode *vp;
+{
+ register struct vnode *vq;
+
+ if (vp->v_flag & VXLOCK) {
+ vp->v_flag |= VXWANT;
+ sleep((caddr_t)vp, PINOD);
+ return (1);
+ }
+ if (vp->v_usecount == 0) {
+ if (vq = vp->v_freef)
+ vq->v_freeb = vp->v_freeb;
+ else
+ vfreet = vp->v_freeb;
+ *vp->v_freeb = vq;
+ vp->v_freef = NULL;
+ vp->v_freeb = NULL;
+ }
+ VREF(vp);
+ VOP_LOCK(vp);
+ return (0);
+}
+
+int bug_refs = 0;
+
+/*
+ * Vnode reference, just increment the count
+ */
+void vref(vp)
+ struct vnode *vp;
+{
+
+ vp->v_usecount++;
+ if (vp->v_type != VBLK && curproc)
+ curproc->p_spare[0]++;
+ if (bug_refs)
+ vprint("vref: ");
+}
+
+/*
+ * vput(), just unlock and vrele()
+ */
+void vput(vp)
+ register struct vnode *vp;
+{
+
+ VOP_UNLOCK(vp);
+ vrele(vp);
+}
+
+/*
+ * Vnode release.
+ * If count drops to zero, call inactive routine and return to freelist.
+ */
+void vrele(vp)
+ register struct vnode *vp;
+{
+ struct proc *p = curproc; /* XXX */
+
+#ifdef DIAGNOSTIC
+ if (vp == NULL)
+ panic("vrele: null vp");
+#endif
+ vp->v_usecount--;
+ if (vp->v_type != VBLK && curproc)
+ curproc->p_spare[0]--;
+ if (bug_refs)
+ vprint("vref: ");
+ if (vp->v_usecount > 0)
+ return;
+#ifdef DIAGNOSTIC
+ if (vp->v_usecount != 0 || vp->v_writecount != 0) {
+ vprint("vrele: bad ref count", vp);
+ panic("vrele: ref cnt");
+ }
+#endif
+ if (vfreeh == NULLVP) {
+ /*
+ * insert into empty list
+ */
+ vfreeh = vp;
+ vp->v_freeb = &vfreeh;
+ } else {
+ /*
+ * insert at tail of list
+ */
+ *vfreet = vp;
+ vp->v_freeb = vfreet;
+ }
+ vp->v_freef = NULL;
+ vfreet = &vp->v_freef;
+ VOP_INACTIVE(vp, p);
+}
+
+/*
+ * Page or buffer structure gets a reference.
+ */
+void vhold(vp)
+ register struct vnode *vp;
+{
+
+ vp->v_holdcnt++;
+}
+
+/*
+ * Page or buffer structure frees a reference.
+ */
+void holdrele(vp)
+ register struct vnode *vp;
+{
+
+ if (vp->v_holdcnt <= 0)
+ panic("holdrele: holdcnt");
+ vp->v_holdcnt--;
+}
+
+/*
+ * Remove any vnodes in the vnode table belonging to mount point mp.
+ *
+ * If MNT_NOFORCE is specified, there should not be any active ones,
+ * return error if any are found (nb: this is a user error, not a
+ * system error). If MNT_FORCE is specified, detach any active vnodes
+ * that are found.
+ */
+int busyprt = 0; /* patch to print out busy vnodes */
+
+vflush(mp, skipvp, flags)
+ struct mount *mp;
+ struct vnode *skipvp;
+ int flags;
+{
+ register struct vnode *vp, *nvp;
+ int busy = 0;
+
+ if ((mp->mnt_flag & MNT_MPBUSY) == 0)
+ panic("vflush: not busy");
+loop:
+ for (vp = mp->mnt_mounth; vp; vp = nvp) {
+ if (vp->v_mount != mp)
+ goto loop;
+ nvp = vp->v_mountf;
+ /*
+ * Skip over a selected vnode.
+ */
+ if (vp == skipvp)
+ continue;
+ /*
+ * Skip over a vnodes marked VSYSTEM.
+ */
+ if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM))
+ continue;
+ /*
+ * With v_usecount == 0, all we need to do is clear
+ * out the vnode data structures and we are done.
+ */
+ if (vp->v_usecount == 0) {
+ vgone(vp);
+ continue;
+ }
+ /*
+ * For block or character devices, revert to an
+ * anonymous device. For all other files, just kill them.
+ */
+ if (flags & FORCECLOSE) {
+ if (vp->v_type != VBLK && vp->v_type != VCHR) {
+ vgone(vp);
+ } else {
+ vclean(vp, 0);
+ vp->v_op = &spec_vnodeops;
+ insmntque(vp, (struct mount *)0);
+ }
+ continue;
+ }
+ if (busyprt)
+ vprint("vflush: busy vnode", vp);
+ busy++;
+ }
+ if (busy)
+ return (EBUSY);
+ return (0);
+}
+
+/*
+ * Disassociate the underlying file system from a vnode.
+ */
+void vclean(vp, flags)
+ register struct vnode *vp;
+ int flags;
+{
+ struct vnodeops *origops;
+ int active;
+ struct proc *p = curproc; /* XXX */
+
+ /*
+ * Check to see if the vnode is in use.
+ * If so we have to reference it before we clean it out
+ * so that its count cannot fall to zero and generate a
+ * race against ourselves to recycle it.
+ */
+ if (active = vp->v_usecount)
+ VREF(vp);
+ /*
+ * Prevent the vnode from being recycled or
+ * brought into use while we clean it out.
+ */
+ if (vp->v_flag & VXLOCK)
+ panic("vclean: deadlock");
+ vp->v_flag |= VXLOCK;
+ /*
+ * Even if the count is zero, the VOP_INACTIVE routine may still
+ * have the object locked while it cleans it out. The VOP_LOCK
+ * ensures that the VOP_INACTIVE routine is done with its work.
+ * For active vnodes, it ensures that no other activity can
+ * occur while the buffer list is being cleaned out.
+ */
+ VOP_LOCK(vp);
+ if (flags & DOCLOSE)
+ vinvalbuf(vp, 1);
+ /*
+ * Prevent any further operations on the vnode from
+ * being passed through to the old file system.
+ */
+ origops = vp->v_op;
+ vp->v_op = &dead_vnodeops;
+ vp->v_tag = VT_NON;
+ /*
+ * If purging an active vnode, it must be unlocked, closed,
+ * and deactivated before being reclaimed.
+ */
+ (*(origops->vop_unlock))(vp);
+ if (active) {
+ if (flags & DOCLOSE)
+ (*(origops->vop_close))(vp, IO_NDELAY, NOCRED, p);
+ (*(origops->vop_inactive))(vp, p);
+ }
+ /*
+ * Reclaim the vnode.
+ */
+ if ((*(origops->vop_reclaim))(vp))
+ panic("vclean: cannot reclaim");
+ if (active)
+ vrele(vp);
+ /*
+ * Done with purge, notify sleepers in vget of the grim news.
+ */
+ vp->v_flag &= ~VXLOCK;
+ if (vp->v_flag & VXWANT) {
+ vp->v_flag &= ~VXWANT;
+ wakeup((caddr_t)vp);
+ }
+}
+
+/*
+ * Eliminate all activity associated with the requested vnode
+ * and with all vnodes aliased to the requested vnode.
+ */
+void vgoneall(vp)
+ register struct vnode *vp;
+{
+ register struct vnode *vq;
+
+ 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);
+}
+
+/*
+ * Eliminate all activity associated with a vnode
+ * in preparation for reuse.
+ */
+void vgone(vp)
+ register struct vnode *vp;
+{
+ register struct vnode *vq;
+ struct vnode *vx;
+
+ /*
+ * 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;
+ }
+ /*
+ * Clean out the filesystem specific data.
+ */
+ vclean(vp, DOCLOSE);
+ /*
+ * Delete from old mount point vnode list, if on one.
+ */
+ if (vp->v_mountb) {
+ if (vq = vp->v_mountf)
+ vq->v_mountb = vp->v_mountb;
+ *vp->v_mountb = vq;
+ vp->v_mountf = NULL;
+ vp->v_mountb = NULL;
+ vp->v_mount = NULL;
+ }
+ /*
+ * If special device, remove it from special device alias list.
+ */
+ if (vp->v_type == VBLK || vp->v_type == VCHR) {
+ if (*vp->v_hashchain == vp) {
+ *vp->v_hashchain = vp->v_specnext;
+ } else {
+ for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
+ if (vq->v_specnext != vp)
+ continue;
+ vq->v_specnext = vp->v_specnext;
+ break;
+ }
+ if (vq == NULL)
+ panic("missing bdev");
+ }
+ if (vp->v_flag & VALIASED) {
+ vx = NULL;
+ for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
+ if (vq->v_rdev != vp->v_rdev ||
+ vq->v_type != vp->v_type)
+ continue;
+ if (vx)
+ break;
+ vx = vq;
+ }
+ if (vx == NULL)
+ panic("missing alias");
+ if (vq == NULL)
+ vx->v_flag &= ~VALIASED;
+ vp->v_flag &= ~VALIASED;
+ }
+ FREE(vp->v_specinfo, M_VNODE);
+ vp->v_specinfo = NULL;
+ }
+ /*
+ * If it is on the freelist, move it to the head of the list.
+ */
+ if (vp->v_freeb) {
+ if (vq = vp->v_freef)
+ vq->v_freeb = vp->v_freeb;
+ else
+ vfreet = vp->v_freeb;
+ *vp->v_freeb = vq;
+ vp->v_freef = vfreeh;
+ vp->v_freeb = &vfreeh;
+ vfreeh->v_freeb = &vp->v_freef;
+ vfreeh = vp;
+ }
+ vp->v_type = VBAD;
+}
+
+/*
+ * Lookup a vnode by device number.
+ */
+vfinddev(dev, type, vpp)
+ dev_t dev;
+ enum vtype type;
+ struct vnode **vpp;
+{
+ register struct vnode *vp;
+
+ for (vp = speclisth[SPECHASH(dev)]; vp; vp = vp->v_specnext) {
+ if (dev != vp->v_rdev || type != vp->v_type)
+ continue;
+ *vpp = vp;
+ return (0);
+ }
+ return (1);
+}
+
+/*
+ * Calculate the total number of references to a special device.
+ */
+vcount(vp)
+ register struct vnode *vp;
+{
+ register struct vnode *vq;
+ int count;
+
+ if ((vp->v_flag & VALIASED) == 0)
+ return (vp->v_usecount);
+loop:
+ for (count = 0, vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
+ if (vq->v_rdev != vp->v_rdev || vq->v_type != vp->v_type)
+ continue;
+ /*
+ * Alias, but not in use, so flush it out.
+ */
+ if (vq->v_usecount == 0) {
+ vgone(vq);
+ goto loop;
+ }
+ count += vq->v_usecount;
+ }
+ return (count);
+}
+
+/*
+ * Print out a description of a vnode.
+ */
+static char *typename[] =
+ { "VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD" };
+
+vprint(label, vp)
+ char *label;
+ register struct vnode *vp;
+{
+ char buf[64];
+
+ if (label != NULL)
+ printf("%s: ", label);
+ printf("type %s, usecount %d, writecount %d, refcount %d,",
+ typename[vp->v_type], vp->v_usecount, vp->v_writecount,
+ vp->v_holdcnt);
+ buf[0] = '\0';
+ if (vp->v_flag & VROOT)
+ strcat(buf, "|VROOT");
+ if (vp->v_flag & VTEXT)
+ strcat(buf, "|VTEXT");
+ if (vp->v_flag & VSYSTEM)
+ strcat(buf, "|VSYSTEM");
+ if (vp->v_flag & VXLOCK)
+ strcat(buf, "|VXLOCK");
+ if (vp->v_flag & VXWANT)
+ strcat(buf, "|VXWANT");
+ if (vp->v_flag & VBWAIT)
+ strcat(buf, "|VBWAIT");
+ if (vp->v_flag & VALIASED)
+ strcat(buf, "|VALIASED");
+ if (buf[0] != '\0')
+ printf(" flags (%s)", &buf[1]);
+ printf("\n\t");
+ VOP_PRINT(vp);
+}
+
+#ifdef DEBUG
+/*
+ * List all of the locked vnodes in the system.
+ * Called when debugging the kernel.
+ */
+printlockedvnodes()
+{
+ register struct mount *mp;
+ register struct vnode *vp;
+
+ printf("Locked vnodes\n");
+ mp = rootfs;
+ do {
+ for (vp = mp->mnt_mounth; vp; vp = vp->v_mountf)
+ if (VOP_ISLOCKED(vp))
+ vprint((char *)0, vp);
+ mp = mp->mnt_next;
+ } while (mp != rootfs);
+}
+#endif
+
+int kinfo_vdebug = 1;
+int kinfo_vgetfailed;
+#define KINFO_VNODESLOP 10
+/*
+ * Dump vnode list (via kinfo).
+ * Copyout address of vnode followed by vnode.
+ */
+/* ARGSUSED */
+kinfo_vnode(op, where, acopysize, arg, aneeded)
+ int op;
+ char *where;
+ int *acopysize, arg, *aneeded;
+{
+ register struct mount *mp = rootfs;
+ struct mount *omp;
+ struct vnode *vp;
+ register char *bp = where, *savebp;
+ char *ewhere = where + *acopysize;
+ int error;
+
+#define VPTRSZ sizeof (struct vnode *)
+#define VNODESZ sizeof (struct vnode)
+ if (where == NULL) {
+ *aneeded = (numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ);
+ return (0);
+ }
+
+ do {
+ if (vfs_busy(mp)) {
+ mp = mp->mnt_next;
+ continue;
+ }
+ savebp = bp;
+again:
+ for (vp = mp->mnt_mounth; vp; vp = vp->v_mountf) {
+ /*
+ * Check that the vp is still associated with
+ * this filesystem. RACE: could have been
+ * recycled onto the same filesystem.
+ */
+ if (vp->v_mount != mp) {
+ if (kinfo_vdebug)
+ printf("kinfo: vp changed\n");
+ bp = savebp;
+ goto again;
+ }
+ if ((bp + VPTRSZ + VNODESZ <= ewhere) &&
+ ((error = copyout((caddr_t)&vp, bp, VPTRSZ)) ||
+ (error = copyout((caddr_t)vp, bp + VPTRSZ,
+ VNODESZ))))
+ return (error);
+ bp += VPTRSZ + VNODESZ;
+ }
+ omp = mp;
+ mp = mp->mnt_next;
+ vfs_unbusy(omp);
+ } while (mp != rootfs);
+
+ *aneeded = bp - where;
+ if (bp > ewhere)
+ *acopysize = ewhere - where;
+ else
+ *acopysize = bp - where;
+ return (0);
projects / unix-history / blobdiff