FreeBSD/Linux Kernel Cross Reference
sys/coda/coda_vnops.c

     /*-
      *             Coda: an Experimental Distributed File System
      *                              Release 3.1
      * 
      *           Copyright (c) 1987-1998 Carnegie Mellon University
      *                          All Rights Reserved
      * 
      * Permission  to  use, copy, modify and distribute this software and its
      * documentation is hereby granted,  provided  that  both  the  copyright
     * notice  and  this  permission  notice  appear  in  all  copies  of the
     * software, derivative works or  modified  versions,  and  any  portions
     * thereof, and that both notices appear in supporting documentation, and
     * that credit is given to Carnegie Mellon University  in  all  documents
     * and publicity pertaining to direct or indirect use of this code or its
     * derivatives.
     * 
     * CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS  KNOWN  TO  HAVE  BUGS,
     * SOME  OF  WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON ALLOWS
     * FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION.   CARNEGIE  MELLON
     * DISCLAIMS  ANY  LIABILITY  OF  ANY  KIND  FOR  ANY  DAMAGES WHATSOEVER
     * RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE  OR  OF
     * ANY DERIVATIVE WORK.
     * 
     * Carnegie  Mellon  encourages  users  of  this  software  to return any
     * improvements or extensions that  they  make,  and  to  grant  Carnegie
     * Mellon the rights to redistribute these changes without encumbrance.
     * 
     *      @(#) src/sys/coda/coda_vnops.c,v 1.1.1.1 1998/08/29 21:14:52 rvb Exp $
     */
    /* 
     * Mach Operating System
     * Copyright (c) 1990 Carnegie-Mellon University
     * Copyright (c) 1989 Carnegie-Mellon University
     * All rights reserved.  The CMU software License Agreement specifies
     * the terms and conditions for use and redistribution.
     */
    
    /*
     * This code was written for the Coda filesystem at Carnegie Mellon
     * University.  Contributers include David Steere, James Kistler, and
     * M. Satyanarayanan.  
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/6.0/sys/coda/coda_vnops.c 145006 2005-04-13 10:59:09Z jeff $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/acct.h>
    #include <sys/errno.h>
    #include <sys/fcntl.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/malloc.h>
    #include <sys/file.h>           /* Must come after sys/malloc.h */
    #include <sys/mount.h>
    #include <sys/mutex.h>
    #include <sys/namei.h>
    #include <sys/proc.h>
    #include <sys/uio.h>
    #include <sys/unistd.h>
    
    #include <vm/vm.h>
    #include <vm/vm_object.h>
    #include <vm/vm_extern.h>
    
    #include <coda/coda.h>
    #include <coda/cnode.h>
    #include <coda/coda_vnops.h>
    #include <coda/coda_venus.h>
    #include <coda/coda_opstats.h>
    #include <coda/coda_subr.h>
    #include <coda/coda_namecache.h>
    #include <coda/coda_pioctl.h>
    
    /* 
     * These flags select various performance enhancements.
     */
    int coda_attr_cache  = 1;       /* Set to cache attributes in the kernel */
    int coda_symlink_cache = 1;     /* Set to cache symbolic link information */
    int coda_access_cache = 1;      /* Set to handle some access checks directly */
    
    /* structure to keep track of vfs calls */
    
    struct coda_op_stats coda_vnodeopstats[CODA_VNODEOPS_SIZE];
    
    #define MARK_ENTRY(op) (coda_vnodeopstats[op].entries++)
    #define MARK_INT_SAT(op) (coda_vnodeopstats[op].sat_intrn++)
    #define MARK_INT_FAIL(op) (coda_vnodeopstats[op].unsat_intrn++)
    #define MARK_INT_GEN(op) (coda_vnodeopstats[op].gen_intrn++)
    
    /* What we are delaying for in printf */
    int coda_printf_delay = 0;  /* in microseconds */
    int coda_vnop_print_entry = 0;
    static int coda_lockdebug = 0;
    
    /*
     * Some NetBSD details:
     * 
    *   coda_start is called at the end of the mount syscall.
    *   coda_init is called at boot time.
    */
   
   #define ENTRY  if(coda_vnop_print_entry) myprintf(("Entered %s\n",__func__))
   
   /* Definition of the vnode operation vector */
   
   struct vop_vector coda_vnodeops = {
       .vop_default = VOP_PANIC,
       .vop_lookup = coda_lookup,          /* lookup */
       .vop_create = coda_create,          /* create */
       .vop_mknod = VOP_PANIC,     /* mknod */
       .vop_open = coda_open,              /* open */
       .vop_close = coda_close,            /* close */
       .vop_access = coda_access,          /* access */
       .vop_getattr = coda_getattr,        /* getattr */
       .vop_setattr = coda_setattr,        /* setattr */
       .vop_read = coda_read,              /* read */
       .vop_write = coda_write,            /* write */
       .vop_ioctl = coda_ioctl,            /* ioctl */
       .vop_fsync = coda_fsync,            /* fsync */
       .vop_remove = coda_remove,          /* remove */
       .vop_link = coda_link,              /* link */
       .vop_rename = coda_rename,          /* rename */
       .vop_mkdir = coda_mkdir,            /* mkdir */
       .vop_rmdir = coda_rmdir,            /* rmdir */
       .vop_symlink = coda_symlink,        /* symlink */
       .vop_readdir = coda_readdir,        /* readdir */
       .vop_readlink = coda_readlink,      /* readlink */
       .vop_inactive = coda_inactive,      /* inactive */
       .vop_reclaim = coda_reclaim,        /* reclaim */
       .vop_lock = coda_lock,              /* lock */
       .vop_unlock = coda_unlock,          /* unlock */
       .vop_bmap = coda_bmap,              /* bmap */
       .vop_print = VOP_PANIC,     /* print */
       .vop_islocked = coda_islocked,      /* islocked */
       .vop_pathconf = coda_pathconf,      /* pathconf */
       .vop_advlock = VOP_NULL,    /* advlock */
       .vop_lease = VOP_NULL,              /* lease */
       .vop_poll = vop_stdpoll,
       .vop_getpages = vop_stdgetpages,    /* pager intf.*/
       .vop_putpages = vop_stdputpages,    /* pager intf.*/
       .vop_getwritemount =        vop_stdgetwritemount,
   
   #if 0
       missing
       .vop_cachedlookup = ufs_lookup,
       .vop_whiteout =     ufs_whiteout,
   #endif
   
   };
   
   /* A generic do-nothing.  For lease_check, advlock */
   int
   coda_vop_nop(void *anon) {
       struct vnodeop_desc **desc = (struct vnodeop_desc **)anon;
   
       if (codadebug) {
           myprintf(("Vnode operation %s called, but unsupported\n",
                     (*desc)->vdesc_name));
       } 
      return (0);
   }
   
   int
   coda_vnodeopstats_init(void)
   {
           register int i;
           
           for(i=0;i<CODA_VNODEOPS_SIZE;i++) {
                   coda_vnodeopstats[i].opcode = i;
                   coda_vnodeopstats[i].entries = 0;
                   coda_vnodeopstats[i].sat_intrn = 0;
                   coda_vnodeopstats[i].unsat_intrn = 0;
                   coda_vnodeopstats[i].gen_intrn = 0;
           }
           return 0;
   }
                   
   /* 
    * coda_open calls Venus to return the device, inode pair of the cache
    * file holding the data. Using iget, coda_open finds the vnode of the
    * cache file, and then opens it.
    */
   int
   coda_open(struct vop_open_args *ap)
   {
       /* 
        * NetBSD can pass the O_EXCL flag in mode, even though the check
        * has already happened.  Venus defensively assumes that if open
        * is passed the EXCL, it must be a bug.  We strip the flag here.
        */
   /* true args */
       register struct vnode **vpp = &(ap->a_vp);
       struct cnode *cp = VTOC(*vpp);
       int flag = ap->a_mode & (~O_EXCL);
       struct ucred *cred = ap->a_cred;
       struct thread *td = ap->a_td;
   /* locals */
       int error;
       struct vnode *vp;
       struct cdev *dev;
       ino_t inode;
   
       MARK_ENTRY(CODA_OPEN_STATS);
   
       /* Check for open of control file. */
       if (IS_CTL_VP(*vpp)) {
           /* XXX */
           /* if (WRITEABLE(flag)) */ 
           if (flag & (FWRITE | O_TRUNC | O_CREAT | O_EXCL)) {
               MARK_INT_FAIL(CODA_OPEN_STATS);
               return(EACCES);
           }
           MARK_INT_SAT(CODA_OPEN_STATS);
           return(0);
       }
   
       error = venus_open(vtomi((*vpp)), &cp->c_fid, flag, cred, td->td_proc, &dev, &inode);
       if (error)
           return (error);
       if (!error) {
           CODADEBUG( CODA_OPEN,myprintf(("open: dev %#lx inode %lu result %d\n",
                                          (u_long)dev2udev(dev), (u_long)inode,
                                          error)); )
       }
   
       /* Translate the <device, inode> pair for the cache file into
          an inode pointer. */
       error = coda_grab_vnode(dev, inode, &vp);
       if (error)
           return (error);
   
       /* We get the vnode back locked.  Needs unlocked */
       VOP_UNLOCK(vp, 0, td);
       /* Keep a reference until the close comes in. */
       vref(*vpp);                
   
       /* Save the vnode pointer for the cache file. */
       if (cp->c_ovp == NULL) {
           cp->c_ovp = vp;
       } else {
           if (cp->c_ovp != vp)
               panic("coda_open:  cp->c_ovp != ITOV(ip)");
       }
       cp->c_ocount++;
   
       /* Flush the attribute cached if writing the file. */
       if (flag & FWRITE) {
           cp->c_owrite++;
           cp->c_flags &= ~C_VATTR;
       }
   
       /* Save the <device, inode> pair for the cache file to speed
          up subsequent page_read's. */
       cp->c_device = dev;
       cp->c_inode = inode;
   
       /* Open the cache file. */
       error = VOP_OPEN(vp, flag, cred, td, -1); 
       if (error) {
           printf("coda_open: VOP_OPEN on container failed %d\n", error);
           return (error);
       }
   /* grab (above) does this when it calls newvnode unless it's in the cache*/
   
       return(error);
   }
   
   /*
    * Close the cache file used for I/O and notify Venus.
    */
   int
   coda_close(struct vop_close_args *ap)
   {
   /* true args */
       struct vnode *vp = ap->a_vp;
       struct cnode *cp = VTOC(vp);
       int flag = ap->a_fflag;
       struct ucred *cred = ap->a_cred;
       struct thread *td = ap->a_td;
   /* locals */
       int error;
   
       MARK_ENTRY(CODA_CLOSE_STATS);
   
       /* Check for close of control file. */
       if (IS_CTL_VP(vp)) {
           MARK_INT_SAT(CODA_CLOSE_STATS);
           return(0);
       }
   
       if (IS_UNMOUNTING(cp)) {
           if (cp->c_ovp) {
   #ifdef  CODA_VERBOSE
               printf("coda_close: destroying container ref %d, ufs vp %p of vp %p/cp %p\n",
                       vrefcnt(vp), cp->c_ovp, vp, cp);
   #endif
   #ifdef  hmm
               vgone(cp->c_ovp);
   #else
               VOP_CLOSE(cp->c_ovp, flag, cred, td); /* Do errors matter here? */
               vrele(cp->c_ovp);
   #endif
           } else {
   #ifdef  CODA_VERBOSE
               printf("coda_close: NO container vp %p/cp %p\n", vp, cp);
   #endif
           }
           return ENODEV;
       } else {
           VOP_CLOSE(cp->c_ovp, flag, cred, td); /* Do errors matter here? */
           vrele(cp->c_ovp);
       }
   
       if (--cp->c_ocount == 0)
           cp->c_ovp = NULL;
   
       if (flag & FWRITE)                    /* file was opened for write */
           --cp->c_owrite;
   
       error = venus_close(vtomi(vp), &cp->c_fid, flag, cred, td->td_proc);
       vrele(CTOV(cp));
   
       CODADEBUG(CODA_CLOSE, myprintf(("close: result %d\n",error)); )
       return(error);
   }
   
   int
   coda_read(struct vop_read_args *ap)
   {
   
       ENTRY;
       return(coda_rdwr(ap->a_vp, ap->a_uio, UIO_READ,
                       ap->a_ioflag, ap->a_cred, ap->a_uio->uio_td));
   }
   
   int
   coda_write(struct vop_write_args *ap)
   {
   
       ENTRY;
       return(coda_rdwr(ap->a_vp, ap->a_uio, UIO_WRITE,
                       ap->a_ioflag, ap->a_cred, ap->a_uio->uio_td));
   }
   
   int
   coda_rdwr(vp, uiop, rw, ioflag, cred, td)
       struct vnode *vp;
       struct uio *uiop;
       enum uio_rw rw;
       int ioflag;
       struct ucred *cred;
       struct thread *td;
   { 
   /* upcall decl */
     /* NOTE: container file operation!!! */
   /* locals */
       struct cnode *cp = VTOC(vp);
       struct vnode *cfvp = cp->c_ovp;
       struct proc *p = td->td_proc;
       struct thread *ltd = td;
       int igot_internally = 0;
       int opened_internally = 0;
       int error = 0;
       int iscore = 0;
   
       MARK_ENTRY(CODA_RDWR_STATS);
   
       CODADEBUG(CODA_RDWR, myprintf(("coda_rdwr(%d, %p, %d, %lld, %d)\n", rw, 
                                 (void *)uiop->uio_iov->iov_base, uiop->uio_resid, 
                                 (long long)uiop->uio_offset, uiop->uio_segflg)); )
           
       /* Check for rdwr of control object. */
       if (IS_CTL_VP(vp)) {
           MARK_INT_FAIL(CODA_RDWR_STATS);
           return(EINVAL);
       }
   
       /* 
        * If file is not already open this must be a page
        * {read,write} request.  Iget the cache file's inode
        * pointer if we still have its <device, inode> pair.
        * Otherwise, we must do an internal open to derive the
        * pair. 
        */
       if (cfvp == NULL) {
           /* 
            * If we're dumping core, do the internal open. Otherwise
            * venus won't have the correct size of the core when
            * it's completely written.
            */
           if (p) {
               PROC_LOCK(p);
               iscore = (p->p_acflag & ACORE);
               PROC_UNLOCK(p);
           }
           else
               ltd = curthread; 
   
           if (cp->c_inode != 0 && !iscore) {
               igot_internally = 1;
               error = coda_grab_vnode(cp->c_device, cp->c_inode, &cfvp);
               if (error) {
                   MARK_INT_FAIL(CODA_RDWR_STATS);
                   return(error);
               }
               /* 
                * We get the vnode back locked by curthread in both Mach and
                * NetBSD.  Needs unlocked 
                */
               VOP_UNLOCK(cfvp, 0, ltd);
           }
           else {
               opened_internally = 1;
               MARK_INT_GEN(CODA_OPEN_STATS);
               error = VOP_OPEN(vp, (rw == UIO_READ ? FREAD : FWRITE), 
                                cred, td, -1);
   printf("coda_rdwr: Internally Opening %p\n", vp);
               if (error) {
                   printf("coda_rdwr: VOP_OPEN on container failed %d\n", error);
                   return (error);
               }
               cfvp = cp->c_ovp;
           }
       }
   
       /* Have UFS handle the call. */
       CODADEBUG(CODA_RDWR, myprintf(("indirect rdwr: fid = %s, refcnt = %d\n",
                                coda_f2s(&cp->c_fid), CTOV(cp)->v_usecount)); )
       if (rw == UIO_READ) {
           error = VOP_READ(cfvp, uiop, ioflag, cred);
       } else {
           error = VOP_WRITE(cfvp, uiop, ioflag, cred);
           /* ufs_write updates the vnode_pager_setsize for the vnode/object */
   
           {   struct vattr attr;
   
               if (VOP_GETATTR(cfvp, &attr, cred, td) == 0) {
                   vnode_pager_setsize(vp, attr.va_size);
               }
           }
       }
   
       if (error)
           MARK_INT_FAIL(CODA_RDWR_STATS);
       else
           MARK_INT_SAT(CODA_RDWR_STATS);
   
       /* Do an internal close if necessary. */
       if (opened_internally) {
           MARK_INT_GEN(CODA_CLOSE_STATS);
           (void)VOP_CLOSE(vp, (rw == UIO_READ ? FREAD : FWRITE), cred, td);
       }
   
       /* Invalidate cached attributes if writing. */
       if (rw == UIO_WRITE)
           cp->c_flags &= ~C_VATTR;
       return(error);
   }
   
   
   
   int
   coda_ioctl(struct vop_ioctl_args *ap)
   {
   /* true args */
       struct vnode *vp = ap->a_vp;
       int com = ap->a_command;
       caddr_t data = ap->a_data;
       int flag = ap->a_fflag;
       struct ucred *cred = ap->a_cred;
       struct thread *td = ap->a_td;
   /* locals */
       int error;
       struct vnode *tvp;
       struct nameidata ndp;
       struct PioctlData *iap = (struct PioctlData *)data;
   
       MARK_ENTRY(CODA_IOCTL_STATS);
   
       CODADEBUG(CODA_IOCTL, myprintf(("in coda_ioctl on %s\n", iap->path));)
           
       /* Don't check for operation on a dying object, for ctlvp it
          shouldn't matter */
           
       /* Must be control object to succeed. */
       if (!IS_CTL_VP(vp)) {
           MARK_INT_FAIL(CODA_IOCTL_STATS);
           CODADEBUG(CODA_IOCTL, myprintf(("coda_ioctl error: vp != ctlvp"));)
               return (EOPNOTSUPP);
       }
       /* Look up the pathname. */
   
       /* Should we use the name cache here? It would get it from
          lookupname sooner or later anyway, right? */
   
       NDINIT(&ndp, LOOKUP, (iap->follow ? FOLLOW : NOFOLLOW), UIO_USERSPACE, iap->path, td);
       error = namei(&ndp);
       tvp = ndp.ni_vp;
   
       if (error) {
           MARK_INT_FAIL(CODA_IOCTL_STATS);
           CODADEBUG(CODA_IOCTL, myprintf(("coda_ioctl error: lookup returns %d\n",
                                      error));)
           return(error);
       }
   
       /* 
        * Make sure this is a coda style cnode, but it may be a
        * different vfsp 
        */
       if (tvp->v_op != &coda_vnodeops) {
           vrele(tvp);
           NDFREE(&ndp, NDF_ONLY_PNBUF);
           MARK_INT_FAIL(CODA_IOCTL_STATS);
           CODADEBUG(CODA_IOCTL, 
                    myprintf(("coda_ioctl error: %s not a coda object\n", 
                           iap->path));)
           return(EINVAL);
       }
   
       if (iap->vi.in_size > VC_MAXDATASIZE) {
           NDFREE(&ndp, 0);
           return(EINVAL);
       }
       error = venus_ioctl(vtomi(tvp), &((VTOC(tvp))->c_fid), com, flag, data, cred, td->td_proc);
   
       if (error)
           MARK_INT_FAIL(CODA_IOCTL_STATS);
       else
           CODADEBUG(CODA_IOCTL, myprintf(("Ioctl returns %d \n", error)); )
   
       vrele(tvp);
       NDFREE(&ndp, NDF_ONLY_PNBUF);
       return(error);
   }
   
   /*
    * To reduce the cost of a user-level venus;we cache attributes in
    * the kernel.  Each cnode has storage allocated for an attribute. If
    * c_vattr is valid, return a reference to it. Otherwise, get the
    * attributes from venus and store them in the cnode.  There is some
    * question if this method is a security leak. But I think that in
    * order to make this call, the user must have done a lookup and
    * opened the file, and therefore should already have access.  
    */
   int
   coda_getattr(struct vop_getattr_args *ap)
   {
   /* true args */
       struct vnode *vp = ap->a_vp;
       struct cnode *cp = VTOC(vp);
       struct vattr *vap = ap->a_vap;
       struct ucred *cred = ap->a_cred;
       struct thread *td = ap->a_td;
   /* locals */
       int error;
   
       MARK_ENTRY(CODA_GETATTR_STATS);
   
       if (IS_UNMOUNTING(cp))
           return ENODEV;
   
       /* Check for getattr of control object. */
       if (IS_CTL_VP(vp)) {
           MARK_INT_FAIL(CODA_GETATTR_STATS);
           return(ENOENT);
       }
   
       /* Check to see if the attributes have already been cached */
       if (VALID_VATTR(cp)) { 
           CODADEBUG(CODA_GETATTR, { myprintf(("attr cache hit: %s\n",
                                           coda_f2s(&cp->c_fid)));});
           CODADEBUG(CODA_GETATTR, if (!(codadebug & ~CODA_GETATTR))
                    print_vattr(&cp->c_vattr); );
           
           *vap = cp->c_vattr;
           MARK_INT_SAT(CODA_GETATTR_STATS);
           return(0);
       }
   
       error = venus_getattr(vtomi(vp), &cp->c_fid, cred, td->td_proc, vap);
   
       if (!error) {
           CODADEBUG(CODA_GETATTR, myprintf(("getattr miss %s: result %d\n",
                                        coda_f2s(&cp->c_fid), error)); )          
               
           CODADEBUG(CODA_GETATTR, if (!(codadebug & ~CODA_GETATTR))
                    print_vattr(vap);      );
           
       {   int size = vap->va_size;
           struct vnode *convp = cp->c_ovp;
           if (convp != (struct vnode *)0) {
               vnode_pager_setsize(convp, size);
           }
       }
           /* If not open for write, store attributes in cnode */   
           if ((cp->c_owrite == 0) && (coda_attr_cache)) {  
               cp->c_vattr = *vap;
               cp->c_flags |= C_VATTR; 
           }
           
       }
       return(error);
   }
   
   int
   coda_setattr(struct vop_setattr_args *ap)
   {
   /* true args */
       register struct vnode *vp = ap->a_vp;
       struct cnode *cp = VTOC(vp);
       register struct vattr *vap = ap->a_vap;
       struct ucred *cred = ap->a_cred;
       struct thread *td = ap->a_td;
   /* locals */
       int error;
   
       MARK_ENTRY(CODA_SETATTR_STATS);
   
       /* Check for setattr of control object. */
       if (IS_CTL_VP(vp)) {
           MARK_INT_FAIL(CODA_SETATTR_STATS);
           return(ENOENT);
       }
   
       if (codadebug & CODADBGMSK(CODA_SETATTR)) {
           print_vattr(vap);
       }
       error = venus_setattr(vtomi(vp), &cp->c_fid, vap, cred, td->td_proc);
   
       if (!error)
           cp->c_flags &= ~C_VATTR;
   
       {   int size = vap->va_size;
           struct vnode *convp = cp->c_ovp;
           if (size != VNOVAL && convp != (struct vnode *)0) {
               vnode_pager_setsize(convp, size);
           }
       }
       CODADEBUG(CODA_SETATTR,     myprintf(("setattr %d\n", error)); )
       return(error);
   }
   
   int
   coda_access(struct vop_access_args *ap)
   {
   /* true args */
       struct vnode *vp = ap->a_vp;
       struct cnode *cp = VTOC(vp);
       int mode = ap->a_mode;
       struct ucred *cred = ap->a_cred;
       struct thread *td = ap->a_td;
   /* locals */
       int error;
   
       MARK_ENTRY(CODA_ACCESS_STATS);
   
       /* Check for access of control object.  Only read access is
          allowed on it. */
       if (IS_CTL_VP(vp)) {
           /* bogus hack - all will be marked as successes */
           MARK_INT_SAT(CODA_ACCESS_STATS);
           return(((mode & VREAD) && !(mode & (VWRITE | VEXEC))) 
                  ? 0 : EACCES);
       }
   
       /*
        * if the file is a directory, and we are checking exec (eg lookup) 
        * access, and the file is in the namecache, then the user must have 
        * lookup access to it.
        */
       if (coda_access_cache) {
           if ((vp->v_type == VDIR) && (mode & VEXEC)) {
               if (coda_nc_lookup(cp, ".", 1, cred)) {
                   MARK_INT_SAT(CODA_ACCESS_STATS);
                   return(0);                     /* it was in the cache */
               }
           }
       }
   
       error = venus_access(vtomi(vp), &cp->c_fid, mode, cred, td->td_proc);
   
       return(error);
   }
   
   int
   coda_readlink(struct vop_readlink_args *ap)
   {
   /* true args */
       struct vnode *vp = ap->a_vp;
       struct cnode *cp = VTOC(vp);
       struct uio *uiop = ap->a_uio;
       struct ucred *cred = ap->a_cred;
       struct thread *td = ap->a_uio->uio_td;
   /* locals */
       int error;
       char *str;
       int len;
   
       MARK_ENTRY(CODA_READLINK_STATS);
   
       /* Check for readlink of control object. */
       if (IS_CTL_VP(vp)) {
           MARK_INT_FAIL(CODA_READLINK_STATS);
           return(ENOENT);
       }
   
       if ((coda_symlink_cache) && (VALID_SYMLINK(cp))) { /* symlink was cached */
           uiop->uio_rw = UIO_READ;
           error = uiomove(cp->c_symlink, (int)cp->c_symlen, uiop);
           if (error)
               MARK_INT_FAIL(CODA_READLINK_STATS);
           else
               MARK_INT_SAT(CODA_READLINK_STATS);
           return(error);
       }
   
       error = venus_readlink(vtomi(vp), &cp->c_fid, cred,
           td != NULL ? td->td_proc : NULL, &str, &len);
   
       if (!error) {
           uiop->uio_rw = UIO_READ;
           error = uiomove(str, len, uiop);
   
           if (coda_symlink_cache) {
               cp->c_symlink = str;
               cp->c_symlen = len;
               cp->c_flags |= C_SYMLINK;
           } else
               CODA_FREE(str, len);
       }
   
       CODADEBUG(CODA_READLINK, myprintf(("in readlink result %d\n",error));)
       return(error);
   }
   
   int
   coda_fsync(struct vop_fsync_args *ap)
   {
   /* true args */
       struct vnode *vp = ap->a_vp;
       struct cnode *cp = VTOC(vp);
       struct thread *td = ap->a_td;
   /* locals */
       struct vnode *convp = cp->c_ovp;
       int error;
      
       MARK_ENTRY(CODA_FSYNC_STATS);
   
       /* Check for fsync on an unmounting object */
       /* The NetBSD kernel, in it's infinite wisdom, can try to fsync
        * after an unmount has been initiated.  This is a Bad Thing,
        * which we have to avoid.  Not a legitimate failure for stats.
        */
       if (IS_UNMOUNTING(cp)) {
           return(ENODEV);
       }
   
       /* Check for fsync of control object. */
       if (IS_CTL_VP(vp)) {
           MARK_INT_SAT(CODA_FSYNC_STATS);
           return(0);
       }
   
       if (convp)
           VOP_FSYNC(convp, MNT_WAIT, td);
   
       /*
        * We see fsyncs with usecount == 1 then usecount == 0.
        * For now we ignore them.
        */
       /*
       VI_LOCK(vp);
       if (!vp->v_usecount) {
           printf("coda_fsync on vnode %p with %d usecount.  c_flags = %x (%x)\n",
                   vp, vp->v_usecount, cp->c_flags, cp->c_flags&C_PURGING);
       }
       VI_UNLOCK(vp);
       */
   
       /*
        * We can expect fsync on any vnode at all if venus is pruging it.
        * Venus can't very well answer the fsync request, now can it?
        * Hopefully, it won't have to, because hopefully, venus preserves
        * the (possibly untrue) invariant that it never purges an open
        * vnode.  Hopefully.
        */
       if (cp->c_flags & C_PURGING) {
           return(0);
       }
   
       /* needs research */
       return 0;
       error = venus_fsync(vtomi(vp), &cp->c_fid, td->td_proc);
   
       CODADEBUG(CODA_FSYNC, myprintf(("in fsync result %d\n",error)); );
       return(error);
   }
   
   int
   coda_inactive(struct vop_inactive_args *ap)
   {
       /* XXX - at the moment, inactive doesn't look at cred, and doesn't
          have a proc pointer.  Oops. */
   /* true args */
       struct vnode *vp = ap->a_vp;
       struct cnode *cp = VTOC(vp);
       struct ucred *cred __attribute__((unused)) = NULL;
       struct thread *td __attribute__((unused)) = curthread;
   /* upcall decl */
   /* locals */
   
       /* We don't need to send inactive to venus - DCS */
       MARK_ENTRY(CODA_INACTIVE_STATS);
   
       if (IS_CTL_VP(vp)) {
           MARK_INT_SAT(CODA_INACTIVE_STATS);
           return 0;
       }
   
       CODADEBUG(CODA_INACTIVE, myprintf(("in inactive, %s, vfsp %p\n",
                                     coda_f2s(&cp->c_fid), vp->v_mount));)
    
       /* If an array has been allocated to hold the symlink, deallocate it */
       if ((coda_symlink_cache) && (VALID_SYMLINK(cp))) {
           if (cp->c_symlink == NULL)
               panic("coda_inactive: null symlink pointer in cnode");
           
           CODA_FREE(cp->c_symlink, cp->c_symlen);
           cp->c_flags &= ~C_SYMLINK;
           cp->c_symlen = 0;
       }
   
       /* Remove it from the table so it can't be found. */
       coda_unsave(cp);
       if ((struct coda_mntinfo *)(vp->v_mount->mnt_data) == NULL) {
           myprintf(("Help! vfsp->vfs_data was NULL, but vnode %p wasn't dying\n", vp));
           panic("badness in coda_inactive\n");
       }
   
       if (IS_UNMOUNTING(cp)) {
   #ifdef  DEBUG
           printf("coda_inactive: IS_UNMOUNTING use %d: vp %p, cp %p\n", vrefcnt(vp), vp, cp);
           if (cp->c_ovp != NULL)
               printf("coda_inactive: cp->ovp != NULL use %d: vp %p, cp %p\n",
                      vrefcnt(vp), vp, cp);
   #endif
       } else {
   #ifdef OLD_DIAGNOSTIC
           if (vrefcnt(CTOV(cp))) {
               panic("coda_inactive: nonzero reference count");
           }
           if (cp->c_ovp != NULL) {
               panic("coda_inactive:  cp->ovp != NULL");
           }
   #endif
           vgone(vp);
       }
   
       MARK_INT_SAT(CODA_INACTIVE_STATS);
       return(0);
   }
   
   /*
    * Remote filesystem operations having to do with directory manipulation.
    */
   
   /* 
    * It appears that in NetBSD, lookup is supposed to return the vnode locked
    */
   int
   coda_lookup(struct vop_lookup_args *ap)
   {
   /* true args */
       struct vnode *dvp = ap->a_dvp;
       struct cnode *dcp = VTOC(dvp);
       struct vnode **vpp = ap->a_vpp;
       /* 
        * It looks as though ap->a_cnp->ni_cnd->cn_nameptr holds the rest
        * of the string to xlate, and that we must try to get at least
        * ap->a_cnp->ni_cnd->cn_namelen of those characters to macth.  I
        * could be wrong. 
        */
       struct componentname  *cnp = ap->a_cnp;
       struct ucred *cred = cnp->cn_cred;
       struct thread *td = cnp->cn_thread;
   /* locals */
       struct cnode *cp;
       const char *nm = cnp->cn_nameptr;
       int len = cnp->cn_namelen;
       CodaFid VFid;
       int vtype;
       int error = 0;
   
       MARK_ENTRY(CODA_LOOKUP_STATS);
   
       CODADEBUG(CODA_LOOKUP, myprintf(("lookup: %s in %s\n",
                                      nm, coda_f2s(&dcp->c_fid))););
   
       /* Check for lookup of control object. */
       if (IS_CTL_NAME(dvp, nm, len)) {
           *vpp = coda_ctlvp;
           vref(*vpp);
           MARK_INT_SAT(CODA_LOOKUP_STATS);
           goto exit;
       }
   
       if (len+1 > CODA_MAXNAMLEN) {
           MARK_INT_FAIL(CODA_LOOKUP_STATS);
   
           CODADEBUG(CODA_LOOKUP, myprintf(("name too long: lookup, %s (%s)\n",
                                            coda_f2s(&dcp->c_fid), nm)););
           *vpp = (struct vnode *)0;
           error = EINVAL;
           goto exit;
       }
       /* First try to look the file up in the cfs name cache */
       /* lock the parent vnode? */
       cp = coda_nc_lookup(dcp, nm, len, cred);
       if (cp) {
           *vpp = CTOV(cp);
           vref(*vpp);
           CODADEBUG(CODA_LOOKUP, 
                    myprintf(("lookup result %d vpp %p\n",error,*vpp));)
       } else {
           
           /* The name wasn't cached, so we need to contact Venus */
           error = venus_lookup(vtomi(dvp), &dcp->c_fid, nm, len, cred, td->td_proc, &VFid, &vtype);
           
           if (error) {
               MARK_INT_FAIL(CODA_LOOKUP_STATS);
   
               CODADEBUG(CODA_LOOKUP, myprintf(("lookup error on %s (%s)%d\n",
                                                coda_f2s(&dcp->c_fid), nm, error));)
               *vpp = (struct vnode *)0;
           } else {
               MARK_INT_SAT(CODA_LOOKUP_STATS);
               CODADEBUG(CODA_LOOKUP, 
                        myprintf(("lookup: %s type %o result %d\n",
                                  coda_f2s(&VFid), vtype, error)); )
               cp = make_coda_node(&VFid, dvp->v_mount, vtype);
               *vpp = CTOV(cp);
               
               /* enter the new vnode in the Name Cache only if the top bit isn't set */
               /* And don't enter a new vnode for an invalid one! */
               if (!(vtype & CODA_NOCACHE))
                   coda_nc_enter(VTOC(dvp), nm, len, cred, VTOC(*vpp));
           }
       }
   
    exit:
       /* 
        * If we are creating, and this was the last name to be looked up,
        * and the error was ENOENT, then there really shouldn't be an
        * error and we can make the leaf NULL and return success.  Since
        * this is supposed to work under Mach as well as NetBSD, we're
        * leaving this fn wrapped.  We also must tell lookup/namei that
        * we need to save the last component of the name.  (Create will
        * have to free the name buffer later...lucky us...)
        */
       if (((cnp->cn_nameiop == CREATE) || (cnp->cn_nameiop == RENAME))
           && (cnp->cn_flags & ISLASTCN)
           && (error == ENOENT))
       {
           error = EJUSTRETURN;
           cnp->cn_flags |= SAVENAME;
           *ap->a_vpp = NULL;
       }
   
       /* 
        * If we are removing, and we are at the last element, and we
        * found it, then we need to keep the name around so that the
        * removal will go ahead as planned.  Unfortunately, this will
        * probably also lock the to-be-removed vnode, which may or may
        * not be a good idea.  I'll have to look at the bits of
        * coda_remove to make sure.  We'll only save the name if we did in
        * fact find the name, otherwise coda_remove won't have a chance
        * to free the pathname.  
        */
       if ((cnp->cn_nameiop == DELETE)
           && (cnp->cn_flags & ISLASTCN)
           && !error)
       {
           cnp->cn_flags |= SAVENAME;
       }
   
       /* 
        * If the lookup went well, we need to (potentially?) unlock the
        * parent, and lock the child.  We are only responsible for
        * checking to see if the parent is supposed to be unlocked before
        * we return.  We must always lock the child (provided there is
        * one, and (the parent isn't locked or it isn't the same as the
        * parent.)  Simple, huh?  We can never leave the parent locked unless
        * we are ISLASTCN
        */
       if (!error || (error == EJUSTRETURN)) {
           if (cnp->cn_flags & ISDOTDOT) {
              if ((error = VOP_UNLOCK(dvp, 0, td))) {
                  return error; 
              }       
              /* 
               * The parent is unlocked.  As long as there is a child,
               * lock it without bothering to check anything else. 
               */
              if (*ap->a_vpp) {
                  if ((error = VOP_LOCK(*ap->a_vpp, LK_EXCLUSIVE, td))) {
                      vn_lock(dvp, LK_RETRY|LK_EXCLUSIVE, td);
                      return (error);
                  }
              }
              vn_lock(dvp, LK_RETRY|LK_EXCLUSIVE, td);
          } else {
              /* The parent is locked, and may be the same as the child */
              if (*ap->a_vpp && (*ap->a_vpp != dvp)) {
                  /* Different, go ahead and lock it. */
                  if ((error = VOP_LOCK(*ap->a_vpp, LK_EXCLUSIVE, td))) {
                      return (error);
                  }
              }
          }
      } else {
          /* If the lookup failed, we need to ensure that the leaf is NULL */
          /* Don't change any locking? */
          *ap->a_vpp = NULL;
      }
      return(error);
  }
  
  /*ARGSUSED*/
  int
  coda_create(struct vop_create_args *ap)
  {
  /* true args */
      struct vnode *dvp = ap->a_dvp;
      struct cnode *dcp = VTOC(dvp);
      struct vattr *va = ap->a_vap;
      int exclusive = 1;
      int mode = ap->a_vap->va_mode;
      struct vnode **vpp = ap->a_vpp;
      struct componentname  *cnp = ap->a_cnp;
      struct ucred *cred = cnp->cn_cred;
      struct thread *td = cnp->cn_thread;
  /* locals */
      int error;
      struct cnode *cp;
      const char *nm = cnp->cn_nameptr;
      int len = cnp->cn_namelen;
      CodaFid VFid;
      struct vattr attr;
  
      MARK_ENTRY(CODA_CREATE_STATS);
  
      /* All creates are exclusive XXX */
      /* I'm assuming the 'mode' argument is the file mode bits XXX */
  
      /* Check for create of control object. */
      if (IS_CTL_NAME(dvp, nm, len)) {
          *vpp = (struct vnode *)0;
          MARK_INT_FAIL(CODA_CREATE_STATS);
          return(EACCES);
      }
  
      error = venus_create(vtomi(dvp), &dcp->c_fid, nm, len, exclusive, mode, va, cred, td->td_proc, &VFid, &attr);
  
      if (!error) {
          
          /* If this is an exclusive create, panic if the file already exists. */
          /* Venus should have detected the file and reported EEXIST. */
  
          if ((exclusive == 1) &&
              (coda_find(&VFid) != NULL))
              panic("cnode existed for newly created file!");
          
          cp = make_coda_node(&VFid, dvp->v_mount, attr.va_type);
          *vpp = CTOV(cp);
          
          /* Update va to reflect the new attributes. */
          (*va) = attr;
          
          /* Update the attribute cache and mark it as valid */
          if (coda_attr_cache) {
              VTOC(*vpp)->c_vattr = attr;
              VTOC(*vpp)->c_flags |= C_VATTR;       
          }
  
          /* Invalidate the parent's attr cache, the modification time has changed */
          VTOC(dvp)->c_flags &= ~C_VATTR;
          
          /* enter the new vnode in the Name Cache */
          coda_nc_enter(VTOC(dvp), nm, len, cred, VTOC(*vpp));
          
          CODADEBUG(CODA_CREATE, 
                    myprintf(("create: %s, result %d\n",
                             coda_f2s(&VFid), error)); )
      } else {
          *vpp = (struct vnode *)0;
          CODADEBUG(CODA_CREATE, myprintf(("create error %d\n", error));)
      }
  
      if (!error) {
          if (cnp->cn_flags & LOCKLEAF) {
              if ((error = VOP_LOCK(*ap->a_vpp, LK_EXCLUSIVE, td))) {
                  printf("coda_create: ");
                  panic("unlocked parent but couldn't lock child");
              }
          }
  #ifdef OLD_DIAGNOSTIC
          else {
              printf("coda_create: LOCKLEAF not set!\n");
          }
  #endif
      }
      return(error);
  }
  
  int
  coda_remove(struct vop_remove_args *ap)
  {
  /* true args */
      struct vnode *dvp = ap->a_dvp;
      struct cnode *cp = VTOC(dvp);
      struct componentname  *cnp = ap->a_cnp;
      struct ucred *cred = cnp->cn_cred;
      struct thread *td = cnp->cn_thread;
  /* locals */
      int error;
      const char *nm = cnp->cn_nameptr;
      int len = cnp->cn_namelen;
      struct cnode *tp;
  
      MARK_ENTRY(CODA_REMOVE_STATS);
  
      CODADEBUG(CODA_REMOVE, myprintf(("remove: %s in %s\n",
                                       nm, coda_f2s(&cp->c_fid))););
      /* Remove the file's entry from the CODA Name Cache */
      /* We're being conservative here, it might be that this person
       * doesn't really have sufficient access to delete the file
       * but we feel zapping the entry won't really hurt anyone -- dcs
       */
      /* I'm gonna go out on a limb here. If a file and a hardlink to it
       * exist, and one is removed, the link count on the other will be
       * off by 1. We could either invalidate the attrs if cached, or
       * fix them. I'll try to fix them. DCS 11/8/94
       */
      tp = coda_nc_lookup(VTOC(dvp), nm, len, cred);
      if (tp) {
          if (VALID_VATTR(tp)) {  /* If attrs are cached */
              if (tp->c_vattr.va_nlink > 1) {     /* If it's a hard link */
                  tp->c_vattr.va_nlink--;
              }
          }
          
          coda_nc_zapfile(VTOC(dvp), nm, len); 
          /* No need to flush it if it doesn't exist! */
      }
      /* Invalidate the parent's attr cache, the modification time has changed */
      VTOC(dvp)->c_flags &= ~C_VATTR;
  
      /* Check for remove of control object. */
      if (IS_CTL_NAME(dvp, nm, len)) {
          MARK_INT_FAIL(CODA_REMOVE_STATS);
          return(ENOENT);
      }
  
      error = venus_remove(vtomi(dvp), &cp->c_fid, nm, len, cred, td->td_proc);
  
      CODADEBUG(CODA_REMOVE, myprintf(("in remove result %d\n",error)); )
  
      return(error);
  }
  
  int
  coda_link(struct vop_link_args *ap)
  {
  /* true args */
      struct vnode *vp = ap->a_vp;
      struct cnode *cp = VTOC(vp);
      struct vnode *tdvp = ap->a_tdvp;
      struct cnode *tdcp = VTOC(tdvp);
      struct componentname *cnp = ap->a_cnp;
      struct ucred *cred = cnp->cn_cred;
      struct thread *td = cnp->cn_thread;
  /* locals */
      int error;
      const char *nm = cnp->cn_nameptr;
      int len = cnp->cn_namelen;
  
      MARK_ENTRY(CODA_LINK_STATS);
  
      if (codadebug & CODADBGMSK(CODA_LINK)) {
          myprintf(("nb_link:   vp fid: %s\n",
                    coda_f2s(&cp->c_fid)));
          myprintf(("nb_link: tdvp fid: %s)\n",
                    coda_f2s(&tdcp->c_fid)));     
      }
      if (codadebug & CODADBGMSK(CODA_LINK)) {
          myprintf(("link:   vp fid: %s\n",
                    coda_f2s(&cp->c_fid)));
          myprintf(("link: tdvp fid: %s\n",
                    coda_f2s(&tdcp->c_fid)));
      }
  
      /* Check for link to/from control object. */
      if (IS_CTL_NAME(tdvp, nm, len) || IS_CTL_VP(vp)) {
          MARK_INT_FAIL(CODA_LINK_STATS);
          return(EACCES);
      }
  
      error = venus_link(vtomi(vp), &cp->c_fid, &tdcp->c_fid, nm, len, cred, td->td_proc);
  
      /* Invalidate the parent's attr cache, the modification time has changed */
      VTOC(tdvp)->c_flags &= ~C_VATTR;
      VTOC(vp)->c_flags &= ~C_VATTR;
  
      CODADEBUG(CODA_LINK,        myprintf(("in link result %d\n",error)); )
  
      return(error);
  }
  
  int
  coda_rename(struct vop_rename_args *ap)
  {
  /* true args */
      struct vnode *odvp = ap->a_fdvp;
      struct cnode *odcp = VTOC(odvp);
      struct componentname  *fcnp = ap->a_fcnp;
      struct vnode *ndvp = ap->a_tdvp;
      struct cnode *ndcp = VTOC(ndvp);
      struct componentname  *tcnp = ap->a_tcnp;
      struct ucred *cred = fcnp->cn_cred;
      struct thread *td = fcnp->cn_thread;
  /* true args */
      int error;
      const char *fnm = fcnp->cn_nameptr;
      int flen = fcnp->cn_namelen;
      const char *tnm = tcnp->cn_nameptr;
      int tlen = tcnp->cn_namelen;
  
      MARK_ENTRY(CODA_RENAME_STATS);
  
      /* Hmmm.  The vnodes are already looked up.  Perhaps they are locked?
         This could be Bad. XXX */
  #ifdef OLD_DIAGNOSTIC
      if ((fcnp->cn_cred != tcnp->cn_cred)
          || (fcnp->cn_thread != tcnp->cn_thread))
      {
          panic("coda_rename: component names don't agree");
      }
  #endif
  
      /* Check for rename involving control object. */ 
      if (IS_CTL_NAME(odvp, fnm, flen) || IS_CTL_NAME(ndvp, tnm, tlen)) {
          MARK_INT_FAIL(CODA_RENAME_STATS);
          return(EACCES);
      }
  
      /* Problem with moving directories -- need to flush entry for .. */
      if (odvp != ndvp) {
          struct cnode *ovcp = coda_nc_lookup(VTOC(odvp), fnm, flen, cred);
          if (ovcp) {
              struct vnode *ovp = CTOV(ovcp);
              if ((ovp) &&
                  (ovp->v_type == VDIR)) /* If it's a directory */
                  coda_nc_zapfile(VTOC(ovp),"..", 2);
          }
      }
  
      /* Remove the entries for both source and target files */
      coda_nc_zapfile(VTOC(odvp), fnm, flen);
      coda_nc_zapfile(VTOC(ndvp), tnm, tlen);
  
      /* Invalidate the parent's attr cache, the modification time has changed */
      VTOC(odvp)->c_flags &= ~C_VATTR;
      VTOC(ndvp)->c_flags &= ~C_VATTR;
  
      if (flen+1 > CODA_MAXNAMLEN) {
          MARK_INT_FAIL(CODA_RENAME_STATS);
          error = EINVAL;
          goto exit;
      }
  
      if (tlen+1 > CODA_MAXNAMLEN) {
          MARK_INT_FAIL(CODA_RENAME_STATS);
          error = EINVAL;
          goto exit;
      }
  
      error = venus_rename(vtomi(odvp), &odcp->c_fid, &ndcp->c_fid, fnm, flen, tnm, tlen, cred, td->td_proc);
  
   exit:
      CODADEBUG(CODA_RENAME, myprintf(("in rename result %d\n",error));)
      /* XXX - do we need to call cache pureg on the moved vnode? */
      cache_purge(ap->a_fvp);
  
      /* It seems to be incumbent on us to drop locks on all four vnodes */
      /* From-vnodes are not locked, only ref'd.  To-vnodes are locked. */
  
      vrele(ap->a_fvp);
      vrele(odvp);
  
      if (ap->a_tvp) {
          if (ap->a_tvp == ndvp) {
              vrele(ap->a_tvp);
          } else {
              vput(ap->a_tvp);
          }
      }
  
      vput(ndvp);
      return(error);
  }
  
  int
  coda_mkdir(struct vop_mkdir_args *ap)
  {
  /* true args */
      struct vnode *dvp = ap->a_dvp;
      struct cnode *dcp = VTOC(dvp);      
      struct componentname  *cnp = ap->a_cnp;
      register struct vattr *va = ap->a_vap;
      struct vnode **vpp = ap->a_vpp;
      struct ucred *cred = cnp->cn_cred;
      struct thread *td = cnp->cn_thread;
  /* locals */
      int error;
      const char *nm = cnp->cn_nameptr;
      int len = cnp->cn_namelen;
      struct cnode *cp;
      CodaFid VFid;
      struct vattr ova;
  
      MARK_ENTRY(CODA_MKDIR_STATS);
  
      /* Check for mkdir of target object. */
      if (IS_CTL_NAME(dvp, nm, len)) {
          *vpp = (struct vnode *)0;
          MARK_INT_FAIL(CODA_MKDIR_STATS);
          return(EACCES);
      }
  
      if (len+1 > CODA_MAXNAMLEN) {
          *vpp = (struct vnode *)0;
          MARK_INT_FAIL(CODA_MKDIR_STATS);
          return(EACCES);
      }
  
      error = venus_mkdir(vtomi(dvp), &dcp->c_fid, nm, len, va, cred, td->td_proc, &VFid, &ova);
  
      if (!error) {
          if (coda_find(&VFid) != NULL)
              panic("cnode existed for newly created directory!");
          
          
          cp =  make_coda_node(&VFid, dvp->v_mount, va->va_type);
          *vpp = CTOV(cp);
          
          /* enter the new vnode in the Name Cache */
          coda_nc_enter(VTOC(dvp), nm, len, cred, VTOC(*vpp));
  
          /* as a side effect, enter "." and ".." for the directory */
          coda_nc_enter(VTOC(*vpp), ".", 1, cred, VTOC(*vpp));
          coda_nc_enter(VTOC(*vpp), "..", 2, cred, VTOC(dvp));
  
          if (coda_attr_cache) {
              VTOC(*vpp)->c_vattr = ova;          /* update the attr cache */
              VTOC(*vpp)->c_flags |= C_VATTR;     /* Valid attributes in cnode */
          }
  
          /* Invalidate the parent's attr cache, the modification time has changed */
          VTOC(dvp)->c_flags &= ~C_VATTR;
          
          CODADEBUG( CODA_MKDIR, myprintf(("mkdir: %s result %d\n",
                                           coda_f2s(&VFid), error)); )
          } else {
          *vpp = (struct vnode *)0;
          CODADEBUG(CODA_MKDIR, myprintf(("mkdir error %d\n",error));)
      }
  
      return(error);
  }
  
  int
  coda_rmdir(struct vop_rmdir_args *ap)
  {
  /* true args */
      struct vnode *dvp = ap->a_dvp;
      struct cnode *dcp = VTOC(dvp);
      struct componentname  *cnp = ap->a_cnp;
      struct ucred *cred = cnp->cn_cred;
      struct thread *td = cnp->cn_thread;
  /* true args */
      int error;
      const char *nm = cnp->cn_nameptr;
      int len = cnp->cn_namelen;
      struct cnode *cp;
     
      MARK_ENTRY(CODA_RMDIR_STATS);
  
      /* Check for rmdir of control object. */
      if (IS_CTL_NAME(dvp, nm, len)) {
          MARK_INT_FAIL(CODA_RMDIR_STATS);
          return(ENOENT);
      }
  
      /* We're being conservative here, it might be that this person
       * doesn't really have sufficient access to delete the file
       * but we feel zapping the entry won't really hurt anyone -- dcs
       */
      /*
       * As a side effect of the rmdir, remove any entries for children of
       * the directory, especially "." and "..".
       */
      cp = coda_nc_lookup(dcp, nm, len, cred);
      if (cp) coda_nc_zapParentfid(&(cp->c_fid), NOT_DOWNCALL);
  
      /* Remove the file's entry from the CODA Name Cache */
      coda_nc_zapfile(dcp, nm, len);
  
      /* Invalidate the parent's attr cache, the modification time has changed */
      dcp->c_flags &= ~C_VATTR;
  
      error = venus_rmdir(vtomi(dvp), &dcp->c_fid, nm, len, cred, td->td_proc);
  
      CODADEBUG(CODA_RMDIR, myprintf(("in rmdir result %d\n", error)); )
  
      return(error);
  }
  
  int
  coda_symlink(struct vop_symlink_args *ap)
  {
  /* true args */
      struct vnode *tdvp = ap->a_dvp;
      struct cnode *tdcp = VTOC(tdvp);    
      struct componentname *cnp = ap->a_cnp;
      struct vattr *tva = ap->a_vap;
      char *path = ap->a_target;
      struct ucred *cred = cnp->cn_cred;
      struct thread *td = cnp->cn_thread;
      struct vnode **vpp = ap->a_vpp;
  /* locals */
      int error;
      /* 
       * XXX I'm assuming the following things about coda_symlink's
       * arguments: 
       *       t(foo) is the new name/parent/etc being created.
       *       lname is the contents of the new symlink. 
       */
      char *nm = cnp->cn_nameptr;
      int len = cnp->cn_namelen;
      int plen = strlen(path);
  
      /* 
       * Here's the strategy for the moment: perform the symlink, then
       * do a lookup to grab the resulting vnode.  I know this requires
       * two communications with Venus for a new sybolic link, but
       * that's the way the ball bounces.  I don't yet want to change
       * the way the Mach symlink works.  When Mach support is
       * deprecated, we should change symlink so that the common case
       * returns the resultant vnode in a vpp argument.
       */
  
      MARK_ENTRY(CODA_SYMLINK_STATS);
  
      /* Check for symlink of control object. */
      if (IS_CTL_NAME(tdvp, nm, len)) {
          MARK_INT_FAIL(CODA_SYMLINK_STATS);
          return(EACCES);
      }
  
      if (plen+1 > CODA_MAXPATHLEN) {
          MARK_INT_FAIL(CODA_SYMLINK_STATS);
          return(EINVAL);
      }
  
      if (len+1 > CODA_MAXNAMLEN) {
          MARK_INT_FAIL(CODA_SYMLINK_STATS);
          error = EINVAL;
          goto exit;
      }
  
      error = venus_symlink(vtomi(tdvp), &tdcp->c_fid, path, plen, nm, len, tva, cred, td->td_proc);
  
      /* Invalidate the parent's attr cache, the modification time has changed */
      tdcp->c_flags &= ~C_VATTR;
  
      if (error == 0)
          error = VOP_LOOKUP(tdvp, vpp, cnp);
  
   exit:    
      CODADEBUG(CODA_SYMLINK, myprintf(("in symlink result %d\n",error)); )
      return(error);
  }
  
  /*
   * Read directory entries.
   */
  int
  coda_readdir(struct vop_readdir_args *ap)
  {
  /* true args */
      struct vnode *vp = ap->a_vp;
      struct cnode *cp = VTOC(vp);
      register struct uio *uiop = ap->a_uio;
      struct ucred *cred = ap->a_cred;
      int *eofflag = ap->a_eofflag;
      u_long **cookies = ap->a_cookies;
      int *ncookies = ap->a_ncookies;
      struct thread *td = ap->a_uio->uio_td;
  /* upcall decl */
  /* locals */
      int error = 0;
  
      MARK_ENTRY(CODA_READDIR_STATS);
  
      CODADEBUG(CODA_READDIR, myprintf(("coda_readdir(%p, %d, %lld, %d)\n",
                                        (void *)uiop->uio_iov->iov_base,
                                        uiop->uio_resid,
                                        (long long)uiop->uio_offset,
                                        uiop->uio_segflg)); )
          
      /* Check for readdir of control object. */
      if (IS_CTL_VP(vp)) {
          MARK_INT_FAIL(CODA_READDIR_STATS);
          return(ENOENT);
      }
  
      {
          /* If directory is not already open do an "internal open" on it. */
          int opened_internally = 0;
          if (cp->c_ovp == NULL) {
              opened_internally = 1;
              MARK_INT_GEN(CODA_OPEN_STATS);
              error = VOP_OPEN(vp, FREAD, cred, td, -1);
  printf("coda_readdir: Internally Opening %p\n", vp);
              if (error) {
                  printf("coda_readdir: VOP_OPEN on container failed %d\n", error);
                  return (error);
              }
          }
          
          /* Have UFS handle the call. */
          CODADEBUG(CODA_READDIR, myprintf(("indirect readdir: fid = %s, refcnt = %d\n", coda_f2s(&cp->c_fid), vp->v_usecount)); )
          error = VOP_READDIR(cp->c_ovp, uiop, cred, eofflag, ncookies,
                                 cookies);
          
          if (error)
              MARK_INT_FAIL(CODA_READDIR_STATS);
          else
              MARK_INT_SAT(CODA_READDIR_STATS);
          
          /* Do an "internal close" if necessary. */ 
          if (opened_internally) {
              MARK_INT_GEN(CODA_CLOSE_STATS);
              (void)VOP_CLOSE(vp, FREAD, cred, td);
          }
      }
  
      return(error);
  }
  
  /*
   * Convert from filesystem blocks to device blocks
   */
  int
  coda_bmap(struct vop_bmap_args *ap)
  {
      /* XXX on the global proc */
  /* true args */
      struct vnode *vp __attribute__((unused)) = ap->a_vp;        /* file's vnode */
      daddr_t bn __attribute__((unused)) = ap->a_bn;      /* fs block number */
      struct bufobj **bop = ap->a_bop;                    /* RETURN bufobj of device */
      daddr_t *bnp __attribute__((unused)) = ap->a_bnp;   /* RETURN device block number */
      struct thread *td __attribute__((unused)) = curthread;
  /* upcall decl */
  /* locals */
  
          int ret = 0;
          struct cnode *cp;
  
          cp = VTOC(vp);
          if (cp->c_ovp) {
                  return EINVAL;
                  ret =  VOP_BMAP(cp->c_ovp, bn, bop, bnp, ap->a_runp, ap->a_runb);
  #if     0
                  printf("VOP_BMAP(cp->c_ovp %p, bn %p, bop %p, bnp %lld, ap->a_runp %p, ap->a_runb %p) = %d\n",
                          cp->c_ovp, bn, bop, bnp, ap->a_runp, ap->a_runb, ret);
  #endif
                  return ret;
          } else {
  #if     0
                  printf("coda_bmap: no container\n");
  #endif
                  return(EOPNOTSUPP);
          }
  }
  
  int
  coda_reclaim(struct vop_reclaim_args *ap)
  {
  /* true args */
      struct vnode *vp = ap->a_vp;
      struct cnode *cp = VTOC(vp);
  /* upcall decl */
  /* locals */
  
  /*
   * Forced unmount/flush will let vnodes with non zero use be destroyed!
   */
      ENTRY;
  
      if (IS_UNMOUNTING(cp)) {
  #ifdef  DEBUG
          if (VTOC(vp)->c_ovp) {
              if (IS_UNMOUNTING(cp))
                  printf("coda_reclaim: c_ovp not void: vp %p, cp %p\n", vp, cp);
          }
  #endif
      } else {
  #ifdef OLD_DIAGNOSTIC
          if (vrefcnt(vp) != 0) 
              print("coda_reclaim: pushing active %p\n", vp);
          if (VTOC(vp)->c_ovp) {
              panic("coda_reclaim: c_ovp not void");
      }
  #endif
      }   
      cache_purge(vp);
      coda_free(VTOC(vp));
      vp->v_data = NULL;
      vnode_destroy_vobject(vp);
      return (0);
  }
  
  int
  coda_lock(struct vop_lock_args *ap)
  {
  /* true args */
      struct vnode *vp = ap->a_vp;
      struct cnode *cp = VTOC(vp);
  /* upcall decl */
  /* locals */
  
      ENTRY;
  
      if ((ap->a_flags & LK_INTERLOCK) == 0) {
          VI_LOCK(vp);
          ap->a_flags |= LK_INTERLOCK;
      }
  
      if (coda_lockdebug) {
          myprintf(("Attempting lock on %s\n",
                    coda_f2s(&cp->c_fid)));
      }
  
      return (vop_stdlock(ap));
  }
  
  int
  coda_unlock(struct vop_unlock_args *ap)
  {
  /* true args */
      struct vnode *vp = ap->a_vp;
      struct cnode *cp = VTOC(vp);
  /* upcall decl */
  /* locals */
  
      ENTRY;
      if (coda_lockdebug) {
          myprintf(("Attempting unlock on %s\n",
                    coda_f2s(&cp->c_fid)));
      }
  
      return (vop_stdunlock(ap));
  }
  
  int
  coda_islocked(struct vop_islocked_args *ap)
  {
  /* true args */
      ENTRY;
  
      return (vop_stdislocked(ap));
  }
  
  /* How one looks up a vnode given a device/inode pair: */
  int
  coda_grab_vnode(struct cdev *dev, ino_t ino, struct vnode **vpp)
  {
      /* This is like VFS_VGET() or igetinode()! */
      int           error;
      struct mount *mp;
  
      if (!(mp = devtomp(dev))) {
          myprintf(("coda_grab_vnode: devtomp(%#lx) returns NULL\n",
                    (u_long)dev2udev(dev)));
          return(ENXIO);
      }
  
      /* XXX - ensure that nonzero-return means failure */
      error = VFS_VGET(mp,ino,LK_EXCLUSIVE,vpp);
      if (error) {
          myprintf(("coda_grab_vnode: iget/vget(%lx, %lu) returns %p, err %d\n", 
                    (u_long)dev2udev(dev), (u_long)ino, (void *)*vpp, error));
          return(ENOENT);
      }
      return(0);
  }
  
  void
  print_vattr( attr )
          struct vattr *attr;
  {
      char *typestr;
  
      switch (attr->va_type) {
      case VNON:
          typestr = "VNON";
          break;
      case VREG:
          typestr = "VREG";
          break;
      case VDIR:
          typestr = "VDIR";
          break;
      case VBLK:
          typestr = "VBLK";
          break;
      case VCHR:
          typestr = "VCHR";
          break;
      case VLNK:
          typestr = "VLNK";
          break;
      case VSOCK:
          typestr = "VSCK";
          break;
      case VFIFO:
          typestr = "VFFO";
          break;
      case VBAD:
          typestr = "VBAD";
          break;
      default:
          typestr = "????";
          break;
      }
  
  
      myprintf(("attr: type %s mode %d uid %d gid %d fsid %d rdev %d\n",
                typestr, (int)attr->va_mode, (int)attr->va_uid,
                (int)attr->va_gid, (int)attr->va_fsid, (int)attr->va_rdev));
  
      myprintf(("      fileid %d nlink %d size %d blocksize %d bytes %d\n",
                (int)attr->va_fileid, (int)attr->va_nlink, 
                (int)attr->va_size,
                (int)attr->va_blocksize,(int)attr->va_bytes));
      myprintf(("      gen %ld flags %ld vaflags %d\n",
                attr->va_gen, attr->va_flags, attr->va_vaflags));
      myprintf(("      atime sec %d nsec %d\n",
                (int)attr->va_atime.tv_sec, (int)attr->va_atime.tv_nsec));
      myprintf(("      mtime sec %d nsec %d\n",
                (int)attr->va_mtime.tv_sec, (int)attr->va_mtime.tv_nsec));
      myprintf(("      ctime sec %d nsec %d\n",
                (int)attr->va_ctime.tv_sec, (int)attr->va_ctime.tv_nsec));
  }
  
  /* How to print a ucred */
  void
  print_cred(cred)
          struct ucred *cred;
  {
  
          int i;
  
          myprintf(("ref %d\tuid %d\n",cred->cr_ref,cred->cr_uid));
  
          for (i=0; i < cred->cr_ngroups; i++)
                  myprintf(("\tgroup %d: (%d)\n",i,cred->cr_groups[i]));
          myprintf(("\n"));
  
  }
  
  /*
   * Return a vnode for the given fid.
   * If no cnode exists for this fid create one and put it
   * in a table hashed by coda_f2i().  If the cnode for
   * this fid is already in the table return it (ref count is
   * incremented by coda_find.  The cnode will be flushed from the
   * table when coda_inactive calls coda_unsave.
   */
  struct cnode *
  make_coda_node(fid, vfsp, type)
       CodaFid *fid; struct mount *vfsp; short type;
  {
      struct cnode *cp;
      int          err;
  
      if ((cp = coda_find(fid)) == NULL) {
          struct vnode *vp;
          
          cp = coda_alloc();
          cp->c_fid = *fid;
          
          err = getnewvnode("coda", vfsp, &coda_vnodeops, &vp);  
          if (err) {                                                
              panic("coda: getnewvnode returned error %d\n", err);   
          }                                                         
          vp->v_data = cp;                                          
          vp->v_type = type;                                      
          cp->c_vnode = vp;                                         
          coda_save(cp);
          
      } else {
          vref(CTOV(cp));
      }
  
      return cp;
  }
  
  int
  coda_pathconf( struct vop_pathconf_args *ap)
  {
          int error;
          register_t *retval;
  
          retval = ap->a_retval;
          error = 0;
  
          switch (ap->a_name) {
          case _PC_NAME_MAX:
                  *retval = CODA_MAXNAMLEN;
                  break;
          case _PC_PATH_MAX:
                  *retval = CODA_MAXPATHLEN;
                  break;
          default:
                  error = vop_stdpathconf(ap);
                  break;
          }
  
          return (error);
  }

Cache object: ca2e77f7492178dcc57bd63da5294b8e