+
+/*
+ * Routines having to do with the management of the vnode table.
+ */
+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()
+{
+ struct vfsops **vfsp;
+
+ /*
+ * Initialize the vnode name cache
+ */
+ nchinit();
+ /*
+ * Initialize each file system type.
+ */
+ for (vfsp = &vfssw[0]; vfsp <= &vfssw[MOUNT_MAXTYPE]; vfsp++) {
+ if (*vfsp == NULL)
+ continue;
+ (*(*vfsp)->vfs_init)();
+ }
+}
+
+/*
+ * Return the next vnode from the free list.
+ */
+getnewvnode(tag, mp, vops, vpp)
+ enum vtagtype tag;
+ struct mount *mp;
+ struct vnodeops *vops;
+ struct vnode **vpp;
+{
+ register struct vnode *vp, *vq;
+
+ 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;
+ }
+ vp->v_type = VNON;
+ cache_purge(vp);
+ vp->v_tag = tag;
+ vp->v_op = vops;
+ insmntque(vp, mp);
+ VREF(vp);
+ *vpp = vp;
+ return (0);
+}
+
+/*
+ * Move a vnode from one mount queue to another.
+ */
+insmntque(vp, mp)
+ register struct vnode *vp;
+ register struct mount *mp;
+{
+ struct vnode *vq;
+
+ /*
+ * 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;
+ }
+ /*
+ * Insert into list of vnodes for the new mount point, if available.
+ */
+ vp->v_mount = mp;
+ if (mp == NULL) {
+ vp->v_mountf = NULL;
+ vp->v_mountb = NULL;
+ return;
+ }
+ if (mp->m_mounth) {
+ vp->v_mountf = mp->m_mounth;
+ vp->v_mountb = &mp->m_mounth;
+ mp->m_mounth->v_mountb = &vp->v_mountf;
+ mp->m_mounth = vp;
+ } else {
+ mp->m_mounth = vp;
+ vp->v_mountb = &mp->m_mounth;
+ vp->v_mountf = NULL;
+ }
+}
+
+/*
+ * Create a vnode for a block device.
+ * Used for root filesystem, argdev, and swap areas.
+ * Also used for memory file system special devices.
+ */
+bdevvp(dev, vpp)
+ dev_t dev;
+ struct vnode **vpp;
+{
+ register struct vnode *vp;
+ struct vnode *nvp;
+ int error;
+
+ error = getnewvnode(VT_NON, (struct mount *)0, &spec_vnodeops, &nvp);
+ if (error) {
+ *vpp = 0;
+ return (error);
+ }
+ vp = nvp;
+ vp->v_type = VBLK;
+ if (nvp = checkalias(vp, dev, (struct mount *)0)) {
+ vput(vp);
+ vp = nvp;
+ }
+ *vpp = vp;
+ return (0);
+}
+
+/*
+ * Check to see if the new vnode represents a special device
+ * for which we already have a vnode (either because of
+ * bdevvp() or because of a different vnode representing
+ * the same block device). If such an alias exists, deallocate
+ * the existing contents and return the aliased vnode. The
+ * caller is responsible for filling it with its new contents.
+ */
+struct vnode *
+checkalias(nvp, nvp_rdev, mp)
+ register struct vnode *nvp;
+ dev_t nvp_rdev;
+ struct mount *mp;
+{
+ register struct vnode *vp;
+ struct vnode **vpp;
+
+ if (nvp->v_type != VBLK && nvp->v_type != VCHR)
+ return ((struct vnode *)0);
+
+ vpp = &speclisth[SPECHASH(nvp_rdev)];
+loop:
+ for (vp = *vpp; vp; vp = vp->v_specnext) {
+ if (nvp_rdev != vp->v_rdev || nvp->v_type != vp->v_type)
+ continue;
+ /*
+ * Alias, but not in use, so flush it out.
+ */
+ if (vp->v_usecount == 0) {
+ vgone(vp);
+ goto loop;
+ }
+ if (vget(vp))
+ goto loop;
+ break;
+ }
+ if (vp == NULL || vp->v_tag != VT_NON) {
+ MALLOC(nvp->v_specinfo, struct specinfo *,
+ sizeof(struct specinfo), M_VNODE, M_WAITOK);
+ nvp->v_rdev = nvp_rdev;
+ nvp->v_hashchain = vpp;
+ nvp->v_specnext = *vpp;
+ *vpp = nvp;
+ if (vp != NULL) {
+ nvp->v_flag |= VALIASED;
+ vp->v_flag |= VALIASED;
+ vput(vp);
+ }
+ return ((struct vnode *)0);
+ }
+ VOP_UNLOCK(vp);
+ vclean(vp, 0);
+ vp->v_op = nvp->v_op;
+ vp->v_tag = nvp->v_tag;
+ nvp->v_type = VNON;
+ insmntque(vp, mp);
+ return (vp);
+}
+
+/*
+ * 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);
+}
+
+/*
+ * Vnode reference, just increment the count
+ */
+void vref(vp)
+ struct vnode *vp;
+{
+
+ vp->v_usecount++;
+}
+
+/*
+ * 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;
+{
+
+ if (vp == NULL)
+ panic("vrele: null vp");
+ vp->v_usecount--;
+ if (vp->v_usecount < 0)
+ vprint("vrele: bad ref count", vp);
+ if (vp->v_usecount > 0)
+ return;
+ if (vfreeh == (struct vnode *)0) {
+ /*
+ * 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);
+}
+
+/*
+ * Page or buffer structure gets a reference.
+ */
+vhold(vp)
+ register struct vnode *vp;
+{
+
+ vp->v_holdcnt++;
+}
+
+/*
+ * Page or buffer structure frees a reference.
+ */
+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;
+
+ for (vp = mp->m_mounth; vp; vp = nvp) {
+ nvp = vp->v_mountf;
+ /*
+ * Skip over a selected vnode.
+ * Used by ufs to skip over the quota structure inode.
+ */
+ if (vp == skipvp)
+ 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 & MNT_FORCE) {
+ 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, doclose)
+ register struct vnode *vp;
+ long doclose;
+{
+ struct vnodeops *origops;
+ int active;
+
+ /*
+ * 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 (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->vn_unlock))(vp);
+ if (active) {
+ if (doclose)
+ (*(origops->vn_close))(vp, 0, NOCRED);
+ (*(origops->vn_inactive))(vp);
+ }
+ /*
+ * Reclaim the vnode.
+ */
+ if ((*(origops->vn_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;
+ long count;
+
+ /*
+ * 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, 1);
+ /*
+ * 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;
+ }
+ /*
+ * 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) {
+ count = 0;
+ for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
+ if (vq->v_rdev != vp->v_rdev ||
+ vq->v_type != vp->v_type)
+ continue;
+ count++;
+ vx = vq;
+ }
+ if (count == 0)
+ panic("missing alias");
+ if (count == 1)
+ 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, refcount %d,", typename[vp->v_type],
+ vp->v_usecount, 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 & VXLOCK)
+ strcat(buf, "|VXLOCK");
+ if (vp->v_flag & VXWANT)
+ strcat(buf, "|VXWANT");
+ if (vp->v_flag & VEXLOCK)
+ strcat(buf, "|VEXLOCK");
+ if (vp->v_flag & VSHLOCK)
+ strcat(buf, "|VSHLOCK");
+ if (vp->v_flag & VLWAIT)
+ strcat(buf, "|VLWAIT");
+ if (vp->v_flag & VALIASED)
+ strcat(buf, "|VALIASED");
+ if (vp->v_flag & VBWAIT)
+ strcat(buf, "|VBWAIT");
+ if (buf[0] != '\0')
+ printf(" flags (%s)", &buf[1]);
+ printf("\n\t");
+ VOP_PRINT(vp);
+}
projects / unix-history / blobdiff