FreeBSD/Linux Kernel Cross Reference
sys/ufs/ufs/ufs_vnops.c

     /*
      * Copyright (c) 1982, 1986, 1989, 1993
      *      The Regents of the University of California.  All rights reserved.
      * (c) UNIX System Laboratories, Inc.
      * All or some portions of this file are derived from material licensed
      * to the University of California by American Telephone and Telegraph
      * Co. or Unix System Laboratories, Inc. and are reproduced herein with
      * the permission of UNIX System Laboratories, Inc.
      *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by the University of
     *      California, Berkeley and its contributors.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      @(#)ufs_vnops.c 8.10 (Berkeley) 4/1/94
     * $FreeBSD: src/sys/ufs/ufs/ufs_vnops.c,v 1.41.2.6 1999/09/05 08:24:10 peter Exp $
     */
    
    #include "opt_quota.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/namei.h>
    #include <sys/resourcevar.h>
    #include <sys/kernel.h>
    #include <sys/fcntl.h>
    #include <sys/stat.h>
    #include <sys/buf.h>
    #include <sys/proc.h>
    #include <sys/conf.h>
    #include <sys/mount.h>
    #include <sys/unistd.h>
    #include <sys/vnode.h>
    #include <sys/malloc.h>
    #include <sys/dirent.h>
    #include <sys/lockf.h>
    
    #include <vm/vm.h>
    
    #include <miscfs/specfs/specdev.h>
    #include <miscfs/fifofs/fifo.h>
    
    #include <ufs/ufs/quota.h>
    #include <ufs/ufs/inode.h>
    #include <ufs/ufs/dir.h>
    #include <ufs/ufs/ufsmount.h>
    #include <ufs/ufs/ufs_extern.h>
    
    static int ufs_chmod __P((struct vnode *, int, struct ucred *, struct proc *));
    static int ufs_chown
            __P((struct vnode *, uid_t, gid_t, struct ucred *, struct proc *));
    
    #ifdef EXT2FS
    #include <gnu/ext2fs/ext2_extern.h>
    #include <gnu/ext2fs/ext2_fs.h>
    #include <gnu/ext2fs/ext2_fs_sb.h>
    #endif /* EXT2FS */
    
    union _qcvt {
            quad_t qcvt;
            long val[2];
    };
    #define SETHIGH(q, h) { \
            union _qcvt tmp; \
            tmp.qcvt = (q); \
            tmp.val[_QUAD_HIGHWORD] = (h); \
            (q) = tmp.qcvt; \
    }
    #define SETLOW(q, l) { \
            union _qcvt tmp; \
            tmp.qcvt = (q); \
            tmp.val[_QUAD_LOWWORD] = (l); \
            (q) = tmp.qcvt; \
    }
    
    /*
    * Create a regular file
    */
   int
   ufs_create(ap)
           struct vop_create_args /* {
                   struct vnode *a_dvp;
                   struct vnode **a_vpp;
                   struct componentname *a_cnp;
                   struct vattr *a_vap;
           } */ *ap;
   {
           int error;
   
           error =
               ufs_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
               ap->a_dvp, ap->a_vpp, ap->a_cnp);
           if (error)
                   return (error);
           return (0);
   }
   
   /*
    * Mknod vnode call
    */
   /* ARGSUSED */
   int
   ufs_mknod(ap)
           struct vop_mknod_args /* {
                   struct vnode *a_dvp;
                   struct vnode **a_vpp;
                   struct componentname *a_cnp;
                   struct vattr *a_vap;
           } */ *ap;
   {
           struct vattr *vap = ap->a_vap;
           struct vnode **vpp = ap->a_vpp;
           struct inode *ip;
           int error;
   
           error = ufs_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
               ap->a_dvp, vpp, ap->a_cnp);
           if (error)
                   return (error);
           ip = VTOI(*vpp);
           ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
           if (vap->va_rdev != VNOVAL) {
                   /*
                    * Want to be able to use this to make badblock
                    * inodes, so don't truncate the dev number.
                    */
                   ip->i_rdev = vap->va_rdev;
           }
           /*
            * Remove inode so that it will be reloaded by VFS_VGET and
            * checked to see if it is an alias of an existing entry in
            * the inode cache.
            */
           vput(*vpp);
           (*vpp)->v_type = VNON;
           vgone(*vpp);
           *vpp = 0;
           return (0);
   }
   
   /*
    * Open called.
    *
    * Nothing to do.
    */
   /* ARGSUSED */
   int
   ufs_open(ap)
           struct vop_open_args /* {
                   struct vnode *a_vp;
                   int  a_mode;
                   struct ucred *a_cred;
                   struct proc *a_p;
           } */ *ap;
   {
   
           /*
            * Files marked append-only must be opened for appending.
            */
           if ((VTOI(ap->a_vp)->i_flags & APPEND) &&
               (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
                   return (EPERM);
           return (0);
   }
   
   /*
    * Close called.
    *
    * Update the times on the inode.
    */
   /* ARGSUSED */
   int
   ufs_close(ap)
           struct vop_close_args /* {
                   struct vnode *a_vp;
                   int  a_fflag;
                   struct ucred *a_cred;
                   struct proc *a_p;
           } */ *ap;
   {
           register struct vnode *vp = ap->a_vp;
           register struct inode *ip = VTOI(vp);
   
           if (vp->v_usecount > 1 && !(ip->i_flag & IN_LOCKED))
                   ITIMES(ip, &time, &time);
           return (0);
   }
   
   int
   ufs_access(ap)
           struct vop_access_args /* {
                   struct vnode *a_vp;
                   int  a_mode;
                   struct ucred *a_cred;
                   struct proc *a_p;
           } */ *ap;
   {
           struct vnode *vp = ap->a_vp;
           struct inode *ip = VTOI(vp);
           struct ucred *cred = ap->a_cred;
           mode_t mask, mode = ap->a_mode;
           register gid_t *gp;
           int i;
   #ifdef QUOTA
           int error;
   #endif
   
           /*
            * Disallow write attempts on read-only file systems;
            * unless the file is a socket, fifo, or a block or
            * character device resident on the file system.
            */
           if (mode & VWRITE) {
                   switch (vp->v_type) {
                   case VDIR:
                   case VLNK:
                   case VREG:
                           if (vp->v_mount->mnt_flag & MNT_RDONLY)
                                   return (EROFS);
   #ifdef QUOTA
                           if (error = getinoquota(ip))
                                   return (error);
   #endif
                           break;
                   }
           }
   
           /* If immutable bit set, nobody gets to write it. */
           if ((mode & VWRITE) && (ip->i_flags & IMMUTABLE))
                   return (EPERM);
   
           /* Otherwise, user id 0 always gets access. */
           if (cred->cr_uid == 0)
                   return (0);
   
           mask = 0;
   
           /* Otherwise, check the owner. */
           if (cred->cr_uid == ip->i_uid) {
                   if (mode & VEXEC)
                           mask |= S_IXUSR;
                   if (mode & VREAD)
                           mask |= S_IRUSR;
                   if (mode & VWRITE)
                           mask |= S_IWUSR;
                   return ((ip->i_mode & mask) == mask ? 0 : EACCES);
           }
   
           /* Otherwise, check the groups. */
           for (i = 0, gp = cred->cr_groups; i < cred->cr_ngroups; i++, gp++)
                   if (ip->i_gid == *gp) {
                           if (mode & VEXEC)
                                   mask |= S_IXGRP;
                           if (mode & VREAD)
                                   mask |= S_IRGRP;
                           if (mode & VWRITE)
                                   mask |= S_IWGRP;
                           return ((ip->i_mode & mask) == mask ? 0 : EACCES);
                   }
   
           /* Otherwise, check everyone else. */
           if (mode & VEXEC)
                   mask |= S_IXOTH;
           if (mode & VREAD)
                   mask |= S_IROTH;
           if (mode & VWRITE)
                   mask |= S_IWOTH;
           return ((ip->i_mode & mask) == mask ? 0 : EACCES);
   }
   
   /* ARGSUSED */
   int
   ufs_getattr(ap)
           struct vop_getattr_args /* {
                   struct vnode *a_vp;
                   struct vattr *a_vap;
                   struct ucred *a_cred;
                   struct proc *a_p;
           } */ *ap;
   {
           register struct vnode *vp = ap->a_vp;
           register struct inode *ip = VTOI(vp);
           register struct vattr *vap = ap->a_vap;
   
           ITIMES(ip, &time, &time);
           /*
            * Copy from inode table
            */
           vap->va_fsid = ip->i_dev;
           vap->va_fileid = ip->i_number;
           vap->va_mode = ip->i_mode & ~IFMT;
           vap->va_nlink = ip->i_nlink;
           vap->va_uid = ip->i_uid;
           vap->va_gid = ip->i_gid;
           vap->va_rdev = (dev_t)ip->i_rdev;
           vap->va_size = ip->i_din.di_size;
           vap->va_atime = ip->i_atime;
           vap->va_mtime = ip->i_mtime;
           vap->va_ctime = ip->i_ctime;
           vap->va_flags = ip->i_flags;
           vap->va_gen = ip->i_gen;
           /* this doesn't belong here */
           if (vp->v_type == VBLK)
                   vap->va_blocksize = BLKDEV_IOSIZE;
           else if (vp->v_type == VCHR)
                   vap->va_blocksize = MAXBSIZE;
           else
                   vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
           vap->va_bytes = dbtob(ip->i_blocks);
           vap->va_type = vp->v_type;
           vap->va_filerev = ip->i_modrev;
           return (0);
   }
   
   /*
    * Set attribute vnode op. called from several syscalls
    */
   int
   ufs_setattr(ap)
           struct vop_setattr_args /* {
                   struct vnode *a_vp;
                   struct vattr *a_vap;
                   struct ucred *a_cred;
                   struct proc *a_p;
           } */ *ap;
   {
           struct vattr *vap = ap->a_vap;
           struct vnode *vp = ap->a_vp;
           struct inode *ip = VTOI(vp);
           struct ucred *cred = ap->a_cred;
           struct proc *p = ap->a_p;
           struct timeval atimeval, mtimeval;
           int error;
   
           /*
            * Check for unsettable attributes.
            */
           if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
               (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
               (vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
               ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
                   return (EINVAL);
           }
           if (vap->va_flags != VNOVAL) {
                   if (vp->v_mount->mnt_flag & MNT_RDONLY)
                           return (EROFS);
                   if (cred->cr_uid != ip->i_uid &&
                       (error = suser(cred, &p->p_acflag)))
                           return (error);
                   if (cred->cr_uid == 0) {
                           if ((ip->i_flags
                               & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) &&
                               securelevel > 0)
                                   return (EPERM);
                           ip->i_flags = vap->va_flags;
                   } else {
                           if (ip->i_flags
                               & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND))
                                   return (EPERM);
                           ip->i_flags &= SF_SETTABLE;
                           ip->i_flags |= (vap->va_flags & UF_SETTABLE);
                   }
                   ip->i_flag |= IN_CHANGE;
                   if (vap->va_flags & (IMMUTABLE | APPEND))
                           return (0);
           }
           if (ip->i_flags & (IMMUTABLE | APPEND))
                   return (EPERM);
           /*
            * Go through the fields and update iff not VNOVAL.
            */
           if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
                   if (vp->v_mount->mnt_flag & MNT_RDONLY)
                           return (EROFS);
                   error = ufs_chown(vp, vap->va_uid, vap->va_gid, cred, p);
                   if (error)
                           return (error);
           }
           if (vap->va_size != VNOVAL) {
                   /*
                    * Disallow write attempts on read-only file systems;
                    * unless the file is a socket, fifo, or a block or
                    * character device resident on the file system.
                    */
                   switch (vp->v_type) {
                   case VDIR:
                           return (EISDIR);
                   case VLNK:
                   case VREG:
                           if (vp->v_mount->mnt_flag & MNT_RDONLY)
                                   return (EROFS);
                           break;
                   }
                   error = VOP_TRUNCATE(vp, vap->va_size, 0, cred, p);
                   if (error)
                           return (error);
           }
           ip = VTOI(vp);
           if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
                   if (vp->v_mount->mnt_flag & MNT_RDONLY)
                           return (EROFS);
                   if (cred->cr_uid != ip->i_uid &&
                       (error = suser(cred, &p->p_acflag)) &&
                       ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
                       (error = VOP_ACCESS(vp, VWRITE, cred, p))))
                           return (error);
                   if (vap->va_atime.tv_sec != VNOVAL)
                           ip->i_flag |= IN_ACCESS;
                   if (vap->va_mtime.tv_sec != VNOVAL)
                           ip->i_flag |= IN_CHANGE | IN_UPDATE;
                   atimeval.tv_sec = vap->va_atime.tv_sec;
                   atimeval.tv_usec = vap->va_atime.tv_nsec / 1000;
                   mtimeval.tv_sec = vap->va_mtime.tv_sec;
                   mtimeval.tv_usec = vap->va_mtime.tv_nsec / 1000;
                   error = VOP_UPDATE(vp, &atimeval, &mtimeval, 1);
                   if (error)
                           return (error);
           }
           error = 0;
           if (vap->va_mode != (mode_t)VNOVAL) {
                   if (vp->v_mount->mnt_flag & MNT_RDONLY)
                           return (EROFS);
                   error = ufs_chmod(vp, (int)vap->va_mode, cred, p);
           }
           return (error);
   }
   
   /*
    * Change the mode on a file.
    * Inode must be locked before calling.
    */
   static int
   ufs_chmod(vp, mode, cred, p)
           register struct vnode *vp;
           register int mode;
           register struct ucred *cred;
           struct proc *p;
   {
           register struct inode *ip = VTOI(vp);
           int error;
   
           if (cred->cr_uid != ip->i_uid) {
               error = suser(cred, &p->p_acflag);
               if (error)
                   return (error);
           }
           if (cred->cr_uid) {
                   if (vp->v_type != VDIR && (mode & S_ISTXT))
                           return (EFTYPE);
                   if (!groupmember(ip->i_gid, cred) && (mode & ISGID))
                           return (EPERM);
           }
           ip->i_mode &= ~ALLPERMS;
           ip->i_mode |= (mode & ALLPERMS);
           ip->i_flag |= IN_CHANGE;
           return (0);
   }
   
   /*
    * Perform chown operation on inode ip;
    * inode must be locked prior to call.
    */
   static int
   ufs_chown(vp, uid, gid, cred, p)
           register struct vnode *vp;
           uid_t uid;
           gid_t gid;
           struct ucred *cred;
           struct proc *p;
   {
           register struct inode *ip = VTOI(vp);
           uid_t ouid;
           gid_t ogid;
           int error = 0;
   #ifdef QUOTA
           register int i;
           long change;
   #endif
   
           if (uid == (uid_t)VNOVAL)
                   uid = ip->i_uid;
           if (gid == (gid_t)VNOVAL)
                   gid = ip->i_gid;
           /*
            * If we don't own the file, are trying to change the owner
            * of the file, or are not a member of the target group,
            * the caller must be superuser or the call fails.
            */
           if ((cred->cr_uid != ip->i_uid || uid != ip->i_uid ||
               (gid != ip->i_gid && !groupmember((gid_t)gid, cred))) &&
               (error = suser(cred, &p->p_acflag)))
                   return (error);
           ogid = ip->i_gid;
           ouid = ip->i_uid;
   #ifdef QUOTA
           if (error = getinoquota(ip))
                   return (error);
           if (ouid == uid) {
                   dqrele(vp, ip->i_dquot[USRQUOTA]);
                   ip->i_dquot[USRQUOTA] = NODQUOT;
           }
           if (ogid == gid) {
                   dqrele(vp, ip->i_dquot[GRPQUOTA]);
                   ip->i_dquot[GRPQUOTA] = NODQUOT;
           }
           change = ip->i_blocks;
           (void) chkdq(ip, -change, cred, CHOWN);
           (void) chkiq(ip, -1, cred, CHOWN);
           for (i = 0; i < MAXQUOTAS; i++) {
                   dqrele(vp, ip->i_dquot[i]);
                   ip->i_dquot[i] = NODQUOT;
           }
   #endif
           ip->i_gid = gid;
           ip->i_uid = uid;
   #ifdef QUOTA
           if ((error = getinoquota(ip)) == 0) {
                   if (ouid == uid) {
                           dqrele(vp, ip->i_dquot[USRQUOTA]);
                           ip->i_dquot[USRQUOTA] = NODQUOT;
                   }
                   if (ogid == gid) {
                           dqrele(vp, ip->i_dquot[GRPQUOTA]);
                           ip->i_dquot[GRPQUOTA] = NODQUOT;
                   }
                   if ((error = chkdq(ip, change, cred, CHOWN)) == 0) {
                           if ((error = chkiq(ip, 1, cred, CHOWN)) == 0)
                                   goto good;
                           else
                                   (void) chkdq(ip, -change, cred, CHOWN|FORCE);
                   }
                   for (i = 0; i < MAXQUOTAS; i++) {
                           dqrele(vp, ip->i_dquot[i]);
                           ip->i_dquot[i] = NODQUOT;
                   }
           }
           ip->i_gid = ogid;
           ip->i_uid = ouid;
           if (getinoquota(ip) == 0) {
                   if (ouid == uid) {
                           dqrele(vp, ip->i_dquot[USRQUOTA]);
                           ip->i_dquot[USRQUOTA] = NODQUOT;
                   }
                   if (ogid == gid) {
                           dqrele(vp, ip->i_dquot[GRPQUOTA]);
                           ip->i_dquot[GRPQUOTA] = NODQUOT;
                   }
                   (void) chkdq(ip, change, cred, FORCE|CHOWN);
                   (void) chkiq(ip, 1, cred, FORCE|CHOWN);
                   (void) getinoquota(ip);
           }
           return (error);
   good:
           if (getinoquota(ip))
                   panic("chown: lost quota");
   #endif /* QUOTA */
           if (ouid != uid || ogid != gid)
                   ip->i_flag |= IN_CHANGE;
           if (ouid != uid && cred->cr_uid != 0)
                   ip->i_mode &= ~ISUID;
           if (ogid != gid && cred->cr_uid != 0)
                   ip->i_mode &= ~ISGID;
           return (0);
   }
   
   /* ARGSUSED */
   int
   ufs_ioctl(ap)
           struct vop_ioctl_args /* {
                   struct vnode *a_vp;
                   int  a_command;
                   caddr_t  a_data;
                   int  a_fflag;
                   struct ucred *a_cred;
                   struct proc *a_p;
           } */ *ap;
   {
   
           return (ENOTTY);
   }
   
   /* ARGSUSED */
   int
   ufs_select(ap)
           struct vop_select_args /* {
                   struct vnode *a_vp;
                   int  a_which;
                   int  a_fflags;
                   struct ucred *a_cred;
                   struct proc *a_p;
           } */ *ap;
   {
   
           /*
            * We should really check to see if I/O is possible.
            */
           return (1);
   }
   
   /*
    * Mmap a file
    *
    * NB Currently unsupported.
    */
   /* ARGSUSED */
   int
   ufs_mmap(ap)
           struct vop_mmap_args /* {
                   struct vnode *a_vp;
                   int  a_fflags;
                   struct ucred *a_cred;
                   struct proc *a_p;
           } */ *ap;
   {
   
           return (EINVAL);
   }
   
   /*
    * Seek on a file
    *
    * Nothing to do, so just return.
    */
   /* ARGSUSED */
   int
   ufs_seek(ap)
           struct vop_seek_args /* {
                   struct vnode *a_vp;
                   off_t  a_oldoff;
                   off_t  a_newoff;
                   struct ucred *a_cred;
           } */ *ap;
   {
   
           return (0);
   }
   
   int
   ufs_remove(ap)
           struct vop_remove_args /* {
                   struct vnode *a_dvp;
                   struct vnode *a_vp;
                   struct componentname *a_cnp;
           } */ *ap;
   {
           struct inode *ip;
           struct vnode *vp = ap->a_vp;
           struct vnode *dvp = ap->a_dvp;
           int error;
   
           ip = VTOI(vp);
           if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
               (VTOI(dvp)->i_flags & APPEND)) {
                   error = EPERM;
                   goto out;
           }
   #ifdef EXT2FS
           if (IS_EXT2_VNODE(dvp)) {
                   error = ext2_dirremove(dvp, ap->a_cnp);
           } else {
                   error = ufs_dirremove(dvp, ap->a_cnp);
           }
   #else
           error = ufs_dirremove(dvp, ap->a_cnp);
   #endif /* EXT2FS */
           if (error == 0) {
                   ip->i_nlink--;
                   ip->i_flag |= IN_CHANGE;
           }
   out:
           if (dvp == vp)
                   vrele(vp);
           else
                   vput(vp);
           vput(dvp);
           return (error);
   }
   
   /*
    * link vnode call
    */
   int
   ufs_link(ap)
           struct vop_link_args /* {
                   struct vnode *a_tdvp;
                   struct vnode *a_vp;
                   struct componentname *a_cnp;
           } */ *ap;
   {
           struct vnode *vp = ap->a_vp;
           struct vnode *tdvp = ap->a_tdvp;
           struct componentname *cnp = ap->a_cnp;
           struct inode *ip;
           struct timeval tv;
           int error;
   
   #ifdef DIAGNOSTIC
           if ((cnp->cn_flags & HASBUF) == 0)
                   panic("ufs_link: no name");
   #endif
           if (vp->v_mount != tdvp->v_mount) {
                   VOP_ABORTOP(tdvp, cnp);
                   error = EXDEV;
                   goto out2;
           }
           if (vp != tdvp && (error = VOP_LOCK(vp))) {
                   VOP_ABORTOP(tdvp, cnp);
                   goto out2;
           }
           ip = VTOI(vp);
           if ((nlink_t)ip->i_nlink >= LINK_MAX) {
                   VOP_ABORTOP(tdvp, cnp);
                   error = EMLINK;
                   goto out1;
           }
           if (ip->i_flags & (IMMUTABLE | APPEND)) {
                   VOP_ABORTOP(tdvp, cnp);
                   error = EPERM;
                   goto out1;
           }
           ip->i_nlink++;
           ip->i_flag |= IN_CHANGE;
           tv = time;
           error = VOP_UPDATE(vp, &tv, &tv, 1);
           if (!error) {
   #ifdef EXT2FS
                   if (IS_EXT2_VNODE(tdvp)) {
                           error = ext2_direnter(ip, tdvp, cnp);
                   } else {
                           error = ufs_direnter(ip, tdvp, cnp);
                   }
   #else
                   error = ufs_direnter(ip, tdvp, cnp);
   #endif /* EXT2FS */
           }
   
           if (error) {
                   ip->i_nlink--;
                   ip->i_flag |= IN_CHANGE;
           }
           FREE(cnp->cn_pnbuf, M_NAMEI);
   out1:
           if (vp != tdvp)
                   VOP_UNLOCK(vp);
   out2:
           vput(tdvp);
           return (error);
   }
   
   
   /*
    * Rename system call.
    *      rename("foo", "bar");
    * is essentially
    *      unlink("bar");
    *      link("foo", "bar");
    *      unlink("foo");
    * but ``atomically''.  Can't do full commit without saving state in the
    * inode on disk which isn't feasible at this time.  Best we can do is
    * always guarantee the target exists.
    *
    * Basic algorithm is:
    *
    * 1) Bump link count on source while we're linking it to the
    *    target.  This also ensure the inode won't be deleted out
    *    from underneath us while we work (it may be truncated by
    *    a concurrent `trunc' or `open' for creation).
    * 2) Link source to destination.  If destination already exists,
    *    delete it first.
    * 3) Unlink source reference to inode if still around. If a
    *    directory was moved and the parent of the destination
    *    is different from the source, patch the ".." entry in the
    *    directory.
    */
   int
   ufs_rename(ap)
           struct vop_rename_args  /* {
                   struct vnode *a_fdvp;
                   struct vnode *a_fvp;
                   struct componentname *a_fcnp;
                   struct vnode *a_tdvp;
                   struct vnode *a_tvp;
                   struct componentname *a_tcnp;
           } */ *ap;
   {
           struct vnode *tvp = ap->a_tvp;
           register struct vnode *tdvp = ap->a_tdvp;
           struct vnode *fvp = ap->a_fvp;
           struct vnode *fdvp = ap->a_fdvp;
           struct componentname *tcnp = ap->a_tcnp;
           struct componentname *fcnp = ap->a_fcnp;
           struct inode *ip, *xp, *dp;
           struct dirtemplate dirbuf;
           struct timeval tv;
           int doingdirectory = 0, oldparent = 0, newparent = 0;
           int error = 0;
           u_char namlen;
   
   #ifdef DIAGNOSTIC
           if ((tcnp->cn_flags & HASBUF) == 0 ||
               (fcnp->cn_flags & HASBUF) == 0)
                   panic("ufs_rename: no name");
   #endif
           /*
            * Check for cross-device rename.
            */
           if ((fvp->v_mount != tdvp->v_mount) ||
               (tvp && (fvp->v_mount != tvp->v_mount))) {
                   error = EXDEV;
   abortit:
                   VOP_ABORTOP(tdvp, tcnp); /* XXX, why not in NFS? */
                   if (tdvp == tvp)
                           vrele(tdvp);
                   else
                           vput(tdvp);
                   if (tvp)
                           vput(tvp);
                   VOP_ABORTOP(fdvp, fcnp); /* XXX, why not in NFS? */
                   vrele(fdvp);
                   vrele(fvp);
                   return (error);
           }
   
           if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
               (VTOI(tdvp)->i_flags & APPEND))) {
                   error = EPERM;
                   goto abortit;
           }
   
           /*
            * Check if just deleting a link name or if we've lost a race.
            * If another process completes the same rename after we've looked
            * up the source and have blocked looking up the target, then the
            * source and target inodes may be identical now although the
            * names were never linked.
            */
           if (fvp == tvp) {
                   if (fvp->v_type == VDIR) {
                           /*
                            * Linked directories are impossible, so we must
                            * have lost the race.  Pretend that the rename
                            * completed before the lookup.
                            */
   #ifdef UFS_RENAME_DEBUG
                           printf("ufs_rename: fvp == tvp for directories\n");
   #endif
                           error = ENOENT;
                           goto abortit;
                   }
   
                   /* Release destination completely. */
                   VOP_ABORTOP(tdvp, tcnp);
                   vput(tdvp);
                   vput(tvp);
   
                   /*
                    * Delete source.  There is another race now that everything
                    * is unlocked, but this doesn't cause any new complications.
                    * Relookup() may find a file that is unrelated to the
                    * original one, or it may fail.  Too bad.
                    */
                   vrele(fdvp);
                   vrele(fvp);
                   fcnp->cn_flags &= ~MODMASK;
                   fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
                   if ((fcnp->cn_flags & SAVESTART) == 0)
                           panic("ufs_rename: lost from startdir");
                   fcnp->cn_nameiop = DELETE;
                   VREF(fdvp);
                   error = relookup(fdvp, &fvp, fcnp);
                   if (error == 0)
                           vrele(fdvp);
                   if (fvp == NULL) {
   #ifdef UFS_RENAME_DEBUG
                           printf("ufs_rename: from name disappeared\n");
   #endif
                           return (ENOENT);
                   }
                   return (VOP_REMOVE(fdvp, fvp, fcnp));
           }
           error = VOP_LOCK(fvp);
           if (error)
                   goto abortit;
           dp = VTOI(fdvp);
           ip = VTOI(fvp);
           if (ip->i_nlink >= LINK_MAX) {
                   VOP_UNLOCK(fvp);
                   error = EMLINK;
                   goto abortit;
           }
           if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
               || (dp->i_flags & APPEND)) {
                   VOP_UNLOCK(fvp);
                   error = EPERM;
                   goto abortit;
           }
           if ((ip->i_mode & IFMT) == IFDIR) {
                   /*
                    * Avoid ".", "..", and aliases of "." for obvious reasons.
                    */
                   if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
                       dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & ISDOTDOT ||
                       (ip->i_flag & IN_RENAME)) {
                           VOP_UNLOCK(fvp);
                           error = EINVAL;
                           goto abortit;
                   }
                   ip->i_flag |= IN_RENAME;
                   oldparent = dp->i_number;
                   doingdirectory++;
           }
           vrele(fdvp);
   
           /*
            * When the target exists, both the directory
            * and target vnodes are returned locked.
            */
           dp = VTOI(tdvp);
           xp = NULL;
           if (tvp)
                   xp = VTOI(tvp);
   
           /*
            * 1) Bump link count while we're moving stuff
            *    around.  If we crash somewhere before
            *    completing our work, the link count
            *    may be wrong, but correctable.
            */
           ip->i_nlink++;
           ip->i_flag |= IN_CHANGE;
           tv = time;
           error = VOP_UPDATE(fvp, &tv, &tv, 1);
           if (error) {
                   VOP_UNLOCK(fvp);
                   goto bad;
           }
   
           /*
            * If ".." must be changed (ie the directory gets a new
            * parent) then the source directory must not be in the
            * directory heirarchy above the target, as this would
            * orphan everything below the source directory. Also
            * the user must have write permission in the source so
            * as to be able to change "..". We must repeat the call
            * to namei, as the parent directory is unlocked by the
            * call to checkpath().
            */
           error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
           VOP_UNLOCK(fvp);
           if (oldparent != dp->i_number)
                   newparent = dp->i_number;
           if (doingdirectory && newparent) {
                   if (error)      /* write access check above */
                           goto bad;
                   if (xp != NULL)
                           vput(tvp);
   #ifdef EXT2FS
                   if (IS_EXT2_VNODE(tdvp)) {
                           error = ext2_checkpath(ip, dp, tcnp->cn_cred);
                   } else {
                           error = ufs_checkpath(ip, dp, tcnp->cn_cred);
                   }
   #else
                   error = ufs_checkpath(ip, dp, tcnp->cn_cred);
   #endif /* EXT2FS */
                   if (error)
                           goto out;
                   if ((tcnp->cn_flags & SAVESTART) == 0)
                           panic("ufs_rename: lost to startdir");
                   VREF(tdvp);
                   error = relookup(tdvp, &tvp, tcnp);
                   if (error)
                           goto out;
                   vrele(tdvp);
                   dp = VTOI(tdvp);
                   xp = NULL;
                  if (tvp)
                          xp = VTOI(tvp);
          }
          /*
           * 2) If target doesn't exist, link the target
           *    to the source and unlink the source.
           *    Otherwise, rewrite the target directory
           *    entry to reference the source inode and
           *    expunge the original entry's existence.
           */
          if (xp == NULL) {
                  if (dp->i_dev != ip->i_dev)
                          panic("rename: EXDEV");
                  /*
                   * Account for ".." in new directory.
                   * When source and destination have the same
                   * parent we don't fool with the link count.
                   */
                  if (doingdirectory && newparent) {
                          if ((nlink_t)dp->i_nlink >= LINK_MAX) {
                                  error = EMLINK;
                                  goto bad;
                          }
                          dp->i_nlink++;
                          dp->i_flag |= IN_CHANGE;
                          error = VOP_UPDATE(tdvp, &tv, &tv, 1);
                          if (error)
                                  goto bad;
                  }
  #ifdef EXT2FS
                  if (IS_EXT2_VNODE(tdvp)) {
                          error = ext2_direnter(ip, tdvp, tcnp);
                  } else {
                          error = ufs_direnter(ip, tdvp, tcnp);
                  }
  #else
                  error = ufs_direnter(ip, tdvp, tcnp);
  #endif /* EXT2FS */
                  if (error) {
                          if (doingdirectory && newparent) {
                                  dp->i_nlink--;
                                  dp->i_flag |= IN_CHANGE;
                                  (void)VOP_UPDATE(tdvp, &tv, &tv, 1);
                          }
                          goto bad;
                  }
                  vput(tdvp);
          } else {
                  if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev)
                          panic("rename: EXDEV");
                  /*
                   * Short circuit rename(foo, foo).
                   */
                  if (xp->i_number == ip->i_number)
                          panic("rename: same file");
                  /*
                   * If the parent directory is "sticky", then the user must
                   * own the parent directory, or the destination of the rename,
                   * otherwise the destination may not be changed (except by
                   * root). This implements append-only directories.
                   */
                  if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
                      tcnp->cn_cred->cr_uid != dp->i_uid &&
                      xp->i_uid != tcnp->cn_cred->cr_uid) {
                          error = EPERM;
                          goto bad;
                  }
                  /*
                   * Target must be empty if a directory and have no links
                   * to it. Also, ensure source and target are compatible
                   * (both directories, or both not directories).
                   */
                  if ((xp->i_mode&IFMT) == IFDIR) {
  #ifdef EXT2FS
                          if (! (IS_EXT2_VNODE(ITOV(xp)) ? 
                                          ext2_dirempty : ufs_dirempty)
  #else
                          if (! ufs_dirempty
  #endif /* EXT2FS */
                                           (xp, dp->i_number, tcnp->cn_cred) || 
                              xp->i_nlink > 2) {
                                  error = ENOTEMPTY;
                                  goto bad;
                          }
                          if (!doingdirectory) {
                                  error = ENOTDIR;
                                  goto bad;
                          }
                          cache_purge(tdvp);
                  } else if (doingdirectory) {
                          error = EISDIR;
                          goto bad;
                  }
  #ifdef EXT2FS
                  if (IS_EXT2_VNODE(ITOV(dp))) {
                          error = ext2_dirrewrite(dp, ip, tcnp);
                  } else {
                          error = ufs_dirrewrite(dp, ip, tcnp);
                  }
  #else
                  error = ufs_dirrewrite(dp, ip, tcnp);
  #endif /* EXT2FS */
                  if (error)
                          goto bad;
                  /*
                   * If the target directory is in the same
                   * directory as the source directory,
                   * decrement the link count on the parent
                   * of the target directory.
                   */
                   if (doingdirectory && !newparent) {
                          dp->i_nlink--;
                          dp->i_flag |= IN_CHANGE;
                  }
                  vput(tdvp);
                  /*
                   * Adjust the link count of the target to
                   * reflect the dirrewrite above.  If this is
                   * a directory it is empty and there are
                   * no links to it, so we can squash the inode and
                   * any space associated with it.  We disallowed
                   * renaming over top of a directory with links to
                   * it above, as the remaining link would point to
                   * a directory without "." or ".." entries.
                   */
                  xp->i_nlink--;
                  if (doingdirectory) {
                          if (--xp->i_nlink != 0)
                                  panic("rename: linked directory");
                          error = VOP_TRUNCATE(tvp, (off_t)0, IO_SYNC,
                              tcnp->cn_cred, tcnp->cn_proc);
                  }
                  xp->i_flag |= IN_CHANGE;
                  vput(tvp);
                  xp = NULL;
          }
  
          /*
           * 3) Unlink the source.
           */
          fcnp->cn_flags &= ~MODMASK;
          fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
          if ((fcnp->cn_flags & SAVESTART) == 0)
                  panic("ufs_rename: lost from startdir");
          VREF(fdvp);
          error = relookup(fdvp, &fvp, fcnp);
          if (error == 0)
                  vrele(fdvp);
          if (fvp != NULL) {
                  xp = VTOI(fvp);
                  dp = VTOI(fdvp);
          } else {
                  /*
                   * From name has disappeared.
                   */
                  if (doingdirectory)
                          panic("rename: lost dir entry");
                  vrele(ap->a_fvp);
                  return (0);
          }
          /*
           * Ensure that the directory entry still exists and has not
           * changed while the new name has been entered. If the source is
           * a file then the entry may have been unlinked or renamed. In
           * either case there is no further work to be done. If the source
           * is a directory then it cannot have been rmdir'ed; its link
           * count of three would cause a rmdir to fail with ENOTEMPTY.
           * The IN_RENAME flag ensures that it cannot be moved by another
           * rename.
           */
          if (xp != ip) {
                  if (doingdirectory)
                          panic("rename: lost dir entry");
          } else {
                  /*
                   * If the source is a directory with a
                   * new parent, the link count of the old
                   * parent directory must be decremented
                   * and ".." set to point to the new parent.
                   */
                  if (doingdirectory && newparent) {
                          dp->i_nlink--;
                          dp->i_flag |= IN_CHANGE;
                          error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
                                  sizeof (struct dirtemplate), (off_t)0,
                                  UIO_SYSSPACE, IO_NODELOCKED,
                                  tcnp->cn_cred, (int *)0, (struct proc *)0);
                          if (error == 0) {
  #                               if (BYTE_ORDER == LITTLE_ENDIAN)
                                          if (fvp->v_mount->mnt_maxsymlinklen <= 0)
                                                  namlen = dirbuf.dotdot_type;
                                          else
                                                  namlen = dirbuf.dotdot_namlen;
  #                               else
                                          namlen = dirbuf.dotdot_namlen;
  #                               endif
  #ifdef EXT2FS
                                  if(IS_EXT2_VNODE(fvp))
                                          namlen = ((struct odirtemplate *)
                                                      &dirbuf)->dotdot_namlen;
  #endif /* EXT2FS */
                                  if (namlen != 2 ||
                                      dirbuf.dotdot_name[0] != '.' ||
                                      dirbuf.dotdot_name[1] != '.') {
                                          ufs_dirbad(xp, (doff_t)12,
                                              "rename: mangled dir");
                                  } else {
                                          dirbuf.dotdot_ino = newparent;
                                          (void) vn_rdwr(UIO_WRITE, fvp,
                                              (caddr_t)&dirbuf,
                                              sizeof (struct dirtemplate),
                                              (off_t)0, UIO_SYSSPACE,
                                              IO_NODELOCKED|IO_SYNC,
                                              tcnp->cn_cred, (int *)0,
                                              (struct proc *)0);
                                          cache_purge(fdvp);
                                  }
                          }
                  }
  #ifdef EXT2FS
                  if (IS_EXT2_VNODE(fdvp)) {
                          error = ext2_dirremove(fdvp, fcnp);
                  } else {
                          error = ufs_dirremove(fdvp, fcnp);
                  }
  #else
                  error = ufs_dirremove(fdvp, fcnp);
  #endif /* EXT2FS */
                  if (!error) {
                          xp->i_nlink--;
                          xp->i_flag |= IN_CHANGE;
                  }
                  xp->i_flag &= ~IN_RENAME;
          }
          if (dp)
                  vput(fdvp);
          if (xp)
                  vput(fvp);
          vrele(ap->a_fvp);
          return (error);
  
  bad:
          if (xp)
                  vput(ITOV(xp));
          vput(ITOV(dp));
  out:
          if (VOP_LOCK(fvp) == 0) {
                  ip->i_nlink--;
                  ip->i_flag |= IN_CHANGE;
                  ip->i_flag &= ~IN_RENAME;
                  vput(fvp);
          } else
                  vrele(fvp);
          return (error);
  }
  
  /*
   * A virgin directory (no blushing please).
   */
  static struct dirtemplate mastertemplate = {
          0, 12, DT_DIR, 1, { '.', 0 },
          0, DIRBLKSIZ - 12, DT_DIR, 2, { '.', '.', 0 }
  };
  static struct odirtemplate omastertemplate = {
          0, 12, 1, { '.', 0 },
          0, DIRBLKSIZ - 12, 2, { '.', '.', 0 }
  };
  
  /*
   * Mkdir system call
   */
  int
  ufs_mkdir(ap)
          struct vop_mkdir_args /* {
                  struct vnode *a_dvp;
                  struct vnode **a_vpp;
                  struct componentname *a_cnp;
                  struct vattr *a_vap;
          } */ *ap;
  {
          register struct vnode *dvp = ap->a_dvp;
          register struct vattr *vap = ap->a_vap;
          register struct componentname *cnp = ap->a_cnp;
          register struct inode *ip, *dp;
          struct vnode *tvp;
          struct dirtemplate dirtemplate, *dtp;
          struct timeval tv;
          int error, dmode;
  
  #ifdef DIAGNOSTIC
          if ((cnp->cn_flags & HASBUF) == 0)
                  panic("ufs_mkdir: no name");
  #endif
          dp = VTOI(dvp);
          if ((nlink_t)dp->i_nlink >= LINK_MAX) {
                  error = EMLINK;
                  goto out;
          }
          dmode = vap->va_mode & 0777;
          dmode |= IFDIR;
          /*
           * Must simulate part of ufs_makeinode here to acquire the inode,
           * but not have it entered in the parent directory. The entry is
           * made later after writing "." and ".." entries.
           */
          error = VOP_VALLOC(dvp, dmode, cnp->cn_cred, &tvp);
          if (error)
                  goto out;
          ip = VTOI(tvp);
          ip->i_uid = cnp->cn_cred->cr_uid;
          ip->i_gid = dp->i_gid;
  #ifdef QUOTA
          if ((error = getinoquota(ip)) ||
              (error = chkiq(ip, 1, cnp->cn_cred, 0))) {
                  free(cnp->cn_pnbuf, M_NAMEI);
                  VOP_VFREE(tvp, ip->i_number, dmode);
                  vput(tvp);
                  vput(dvp);
                  return (error);
          }
  #endif
          ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
          ip->i_mode = dmode;
          tvp->v_type = VDIR;     /* Rest init'd in getnewvnode(). */
          ip->i_nlink = 2;
          tv = time;
          error = VOP_UPDATE(tvp, &tv, &tv, 1);
  
          /*
           * Bump link count in parent directory
           * to reflect work done below.  Should
           * be done before reference is created
           * so reparation is possible if we crash.
           */
          dp->i_nlink++;
          dp->i_flag |= IN_CHANGE;
          error = VOP_UPDATE(dvp, &tv, &tv, 1);
          if (error)
                  goto bad;
  
          /* Initialize directory with "." and ".." from static template. */
          if (dvp->v_mount->mnt_maxsymlinklen > 0
  #ifdef EXT2FS
                  /* omastertemplate is want we want for EXT2 */
                  && !IS_EXT2_VNODE(dvp) 
  #endif /* EXT2FS */
          )
                  dtp = &mastertemplate;
          else
                  dtp = (struct dirtemplate *)&omastertemplate;
          dirtemplate = *dtp;
          dirtemplate.dot_ino = ip->i_number;
          dirtemplate.dotdot_ino = dp->i_number;
  #ifdef EXT2FS
          /* note that in ext2 DIRBLKSIZ == blocksize, not DEV_BSIZE 
           * so let's just redefine it - for this function only
           */
  #undef  DIRBLKSIZ 
  #define DIRBLKSIZ (IS_EXT2_VNODE(dvp) ? \
                     VTOI(dvp)->i_e2fs->s_blocksize : DEV_BSIZE)
          if(IS_EXT2_VNODE(dvp))
                  dirtemplate.dotdot_reclen = DIRBLKSIZ - 12;
  #endif /* EXT2FS */
          error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)&dirtemplate,
              sizeof (dirtemplate), (off_t)0, UIO_SYSSPACE,
              IO_NODELOCKED|IO_SYNC, cnp->cn_cred, (int *)0, (struct proc *)0);
          if (error) {
                  dp->i_nlink--;
                  dp->i_flag |= IN_CHANGE;
                  goto bad;
          }
          if (DIRBLKSIZ > VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
                  panic("ufs_mkdir: blksize"); /* XXX should grow with balloc() */
          else {
                  ip->i_size = DIRBLKSIZ;
                  ip->i_flag |= IN_CHANGE;
          }
  
          /* Directory set up, now install it's entry in the parent directory. */
  #ifdef EXT2FS
          if (IS_EXT2_VNODE(dvp)) {
                  error = ext2_direnter(ip, dvp, cnp);
          } else {
                  error = ufs_direnter(ip, dvp, cnp);
          }
  #else
          error = ufs_direnter(ip, dvp, cnp);
  #endif /* EXT2FS */
          if (error) {
                  dp->i_nlink--;
                  dp->i_flag |= IN_CHANGE;
          }
  bad:
          /*
           * No need to do an explicit VOP_TRUNCATE here, vrele will do this
           * for us because we set the link count to 0.
           */
          if (error) {
                  ip->i_nlink = 0;
                  ip->i_flag |= IN_CHANGE;
                  vput(tvp);
          } else
                  *ap->a_vpp = tvp;
  out:
          FREE(cnp->cn_pnbuf, M_NAMEI);
          vput(dvp);
          return (error);
  #ifdef EXT2FS
  #undef  DIRBLKSIZ
  #define DIRBLKSIZ  DEV_BSIZE
  #endif /* EXT2FS */
  }
  
  /*
   * Rmdir system call.
   */
  int
  ufs_rmdir(ap)
          struct vop_rmdir_args /* {
                  struct vnode *a_dvp;
                  struct vnode *a_vp;
                  struct componentname *a_cnp;
          } */ *ap;
  {
          struct vnode *vp = ap->a_vp;
          struct vnode *dvp = ap->a_dvp;
          struct componentname *cnp = ap->a_cnp;
          struct inode *ip, *dp;
          int error;
  
          ip = VTOI(vp);
          dp = VTOI(dvp);
          /*
           * No rmdir "." please.
           */
          if (dp == ip) {
                  vrele(dvp);
                  vput(vp);
                  return (EINVAL);
          }
          /*
           * Verify the directory is empty (and valid).
           * (Rmdir ".." won't be valid since
           *  ".." will contain a reference to
           *  the current directory and thus be
           *  non-empty.)
           * Do not allow the removal of mounted on
           * directories (this can happen when an NFS
           * exported filesystem tries to remove a
           * locally mounted on directory).
           */
          error = 0;
          if (ip->i_nlink != 2 ||
  #ifdef EXT2FS
              !(IS_EXT2_VNODE(ITOV(ip)) ? ext2_dirempty : ufs_dirempty)
                           (ip, dp->i_number, cnp->cn_cred)) {
  #else
              !ufs_dirempty(ip, dp->i_number, cnp->cn_cred)) {
  #endif /* EXT2FS */
                  error = ENOTEMPTY;
                  goto out;
          }
          if ((dp->i_flags & APPEND)
              || (ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
                  error = EPERM;
                  goto out;
          }
          if (vp->v_mountedhere != 0) {
                  error = EINVAL;
                  goto out;
          }
          /*
           * Delete reference to directory before purging
           * inode.  If we crash in between, the directory
           * will be reattached to lost+found,
           */
  #ifdef EXT2FS
          if (IS_EXT2_VNODE(dvp)) {
                  error = ext2_dirremove(dvp, cnp);
          } else {
                  error = ufs_dirremove(dvp, cnp);
          }
  #else
          error = ufs_dirremove(dvp, cnp);
  #endif /* EXT2FS */
          if (error)
                  goto out;
          dp->i_nlink--;
          dp->i_flag |= IN_CHANGE;
          cache_purge(dvp);
          vput(dvp);
          dvp = NULL;
          /*
           * Truncate inode.  The only stuff left
           * in the directory is "." and "..".  The
           * "." reference is inconsequential since
           * we're quashing it.  The ".." reference
           * has already been adjusted above.  We've
           * removed the "." reference and the reference
           * in the parent directory, but there may be
           * other hard links so decrement by 2 and
           * worry about them later.
           */
          ip->i_nlink -= 2;
          error = VOP_TRUNCATE(vp, (off_t)0, IO_SYNC, cnp->cn_cred,
              cnp->cn_proc);
          cache_purge(ITOV(ip));
  out:
          if (dvp)
                  vput(dvp);
          vput(vp);
          return (error);
  }
  
  /*
   * symlink -- make a symbolic link
   */
  int
  ufs_symlink(ap)
          struct vop_symlink_args /* {
                  struct vnode *a_dvp;
                  struct vnode **a_vpp;
                  struct componentname *a_cnp;
                  struct vattr *a_vap;
                  char *a_target;
          } */ *ap;
  {
          register struct vnode *vp, **vpp = ap->a_vpp;
          register struct inode *ip;
          int len, error;
  
          error = ufs_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
              vpp, ap->a_cnp);
          if (error)
                  return (error);
          vp = *vpp;
          len = strlen(ap->a_target);
          if (len < vp->v_mount->mnt_maxsymlinklen) {
                  ip = VTOI(vp);
                  bcopy(ap->a_target, (char *)ip->i_shortlink, len);
                  ip->i_size = len;
                  ip->i_flag |= IN_CHANGE | IN_UPDATE;
          } else
                  error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
                      UIO_SYSSPACE, IO_NODELOCKED, ap->a_cnp->cn_cred, (int *)0,
                      (struct proc *)0);
          vput(vp);
          return (error);
  }
  
  /*
   * Vnode op for reading directories.
   *
   * The routine below assumes that the on-disk format of a directory
   * is the same as that defined by <sys/dirent.h>. If the on-disk
   * format changes, then it will be necessary to do a conversion
   * from the on-disk format that read returns to the format defined
   * by <sys/dirent.h>.
   */
  int
  ufs_readdir(ap)
          struct vop_readdir_args /* {
                  struct vnode *a_vp;
                  struct uio *a_uio;
                  struct ucred *a_cred;
                  int *a_ncookies;
                  u_int **cookies;
          } */ *ap;
  {
          register struct uio *uio = ap->a_uio;
          off_t off;
          int count, lost, error;
  
          if (ap->a_ncookies != NULL)
                  /*
                   * Ensure that the block is aligned.  The caller can use
                   * the cookies to determine where in the block to start.
                   */
                  uio->uio_offset &= ~(DIRBLKSIZ - 1);
          off = uio->uio_offset;
          count = uio->uio_resid;
          count &= ~(DIRBLKSIZ - 1);
          lost = uio->uio_resid - count;
          if (count < DIRBLKSIZ || (uio->uio_offset & (DIRBLKSIZ -1)))
                  return (EINVAL);
          uio->uio_resid = count;
          uio->uio_iov->iov_len = count;
  #       if (BYTE_ORDER == LITTLE_ENDIAN)
                  if (ap->a_vp->v_mount->mnt_maxsymlinklen > 0) {
                          error = VOP_READ(ap->a_vp, uio, 0, ap->a_cred);
                  } else {
                          struct dirent *dp, *edp;
                          struct uio auio;
                          struct iovec aiov;
                          caddr_t dirbuf;
                          int readcnt;
                          u_char tmp;
  
                          auio = *uio;
                          auio.uio_iov = &aiov;
                          auio.uio_iovcnt = 1;
                          auio.uio_segflg = UIO_SYSSPACE;
                          aiov.iov_len = count;
                          MALLOC(dirbuf, caddr_t, count, M_TEMP, M_WAITOK);
                          aiov.iov_base = dirbuf;
                          error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred);
                          if (error == 0) {
                                  readcnt = count - auio.uio_resid;
                                  edp = (struct dirent *)&dirbuf[readcnt];
                                  for (dp = (struct dirent *)dirbuf; dp < edp; ) {
                                          tmp = dp->d_namlen;
                                          dp->d_namlen = dp->d_type;
                                          dp->d_type = tmp;
                                          if (dp->d_reclen > 0) {
                                                  dp = (struct dirent *)
                                                      ((char *)dp + dp->d_reclen);
                                          } else {
                                                  error = EIO;
                                                  break;
                                          }
                                  }
                                  if (dp >= edp)
                                          error = uiomove(dirbuf, readcnt, uio);
                          }
                          FREE(dirbuf, M_TEMP);
                  }
  #       else
                  error = VOP_READ(ap->a_vp, uio, 0, ap->a_cred);
  #       endif
          if (!error && ap->a_ncookies != NULL) {
                  struct dirent* dpStart;
                  struct dirent* dpEnd;
                  struct dirent* dp;
                  int ncookies;
                  u_int *cookies;
                  u_int *cookiep;
  
                  if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
                          panic("ufs_readdir: unexpected uio from NFS server");
                  dpStart = (struct dirent *)
                       (uio->uio_iov->iov_base - (uio->uio_offset - off));
                  dpEnd = (struct dirent *) uio->uio_iov->iov_base;
                  for (dp = dpStart, ncookies = 0;
                       dp < dpEnd;
                       dp = (struct dirent *)((caddr_t) dp + dp->d_reclen))
                          ncookies++;
                  MALLOC(cookies, u_int *, ncookies * sizeof(u_int),
                         M_TEMP, M_WAITOK);
                  for (dp = dpStart, cookiep = cookies;
                       dp < dpEnd;
                       dp = (struct dirent *)((caddr_t) dp + dp->d_reclen)) {
                          off += dp->d_reclen;
                          *cookiep++ = (u_int) off;
                  }
                  *ap->a_ncookies = ncookies;
                  *ap->a_cookies = cookies;
          }
          if (ap->a_eofflag)
              *ap->a_eofflag = VTOI(ap->a_vp)->i_size <= uio->uio_offset;
          uio->uio_resid += lost;
          return (error);
  }
  
  /*
   * Return target name of a symbolic link
   */
  int
  ufs_readlink(ap)
          struct vop_readlink_args /* {
                  struct vnode *a_vp;
                  struct uio *a_uio;
                  struct ucred *a_cred;
          } */ *ap;
  {
          register struct vnode *vp = ap->a_vp;
          register struct inode *ip = VTOI(vp);
          int isize;
  
          isize = ip->i_size;
          if ((isize < vp->v_mount->mnt_maxsymlinklen) ||
              (ip->i_din.di_blocks == 0)) {       /* XXX - for old fastlink support */
                  uiomove((char *)ip->i_shortlink, isize, ap->a_uio);
                  return (0);
          }
          return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
  }
  
  /*
   * Ufs abort op, called after namei() when a CREATE/DELETE isn't actually
   * done. If a buffer has been saved in anticipation of a CREATE, delete it.
   */
  /* ARGSUSED */
  int
  ufs_abortop(ap)
          struct vop_abortop_args /* {
                  struct vnode *a_dvp;
                  struct componentname *a_cnp;
          } */ *ap;
  {
          if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF)
                  FREE(ap->a_cnp->cn_pnbuf, M_NAMEI);
          return (0);
  }
  
  /*
   * Lock an inode. If its already locked, set the WANT bit and sleep.
   */
  int
  ufs_lock(ap)
          struct vop_lock_args /* {
                  struct vnode *a_vp;
          } */ *ap;
  {
          struct proc *p = curproc;
          register struct vnode *vp = ap->a_vp;
          register struct inode *ip;
  
  start:
          while (vp->v_flag & VXLOCK) {
                  vp->v_flag |= VXWANT;
                  (void) tsleep((caddr_t)vp, PINOD, "ufslk1", 0);
          }
          if (vp->v_tag == VT_NON)
                  return (ENOENT);
          ip = VTOI(vp);
          if (ip->i_flag & IN_LOCKED) {
                  if (p->p_pid == ip->i_lockholder) {
                          if( (ip->i_flag & IN_RECURSE) == 0)
                                  panic("ufs_lock: recursive lock not expected, pid: %d\n",
                                          ip->i_lockholder);
                  } else {
                          ip->i_flag |= IN_WANTED;
  #ifdef DIAGNOSTIC
                          if (p)
                                  ip->i_lockwaiter = p->p_pid;
                          else
                                  ip->i_lockwaiter = -1;
  #endif
                          (void) tsleep((caddr_t)ip, PINOD, "ufslk2", 0);
                          goto start;
                  }
          }
  #ifdef DIAGNOSTIC
          ip->i_lockwaiter = 0;
          if (((ip->i_flag & IN_RECURSE) == 0) && (ip->i_lockholder != 0))
                  panic("lockholder (%d) != 0", ip->i_lockholder);
          if (p && p->p_pid == 0)
                  printf("locking by process 0\n");
  #endif
  
          if ((ip->i_flag & IN_RECURSE) == 0)
                  ip->i_lockcount = 1;
          else
                  ++ip->i_lockcount;
  
          if (p)
                  ip->i_lockholder = p->p_pid;
          else
                  ip->i_lockholder = -1;
          ip->i_flag |= IN_LOCKED;
          return (0);
  }
  
  /*
   * Unlock an inode.  If WANT bit is on, wakeup.
   */
  int lockcount = 90;
  int
  ufs_unlock(ap)
          struct vop_unlock_args /* {
                  struct vnode *a_vp;
          } */ *ap;
  {
          register struct inode *ip = VTOI(ap->a_vp);
  
  #ifdef DIAGNOSTIC
          struct proc *p = curproc;
  
          if ((ip->i_flag & IN_LOCKED) == 0) {
                  vprint("ufs_unlock: unlocked inode", ap->a_vp);
                  panic("ufs_unlock NOT LOCKED");
          }
          if (p && p->p_pid != ip->i_lockholder && p->p_pid > -1 &&
              ip->i_lockholder > -1 && lockcount++ < 100)
                  panic("unlocker (%d) != lock holder (%d)",
                      p->p_pid, ip->i_lockholder);
  #endif
          if (--ip->i_lockcount > 0) {
                  if ((ip->i_flag & IN_RECURSE) == 0)
                          panic("ufs_unlock: recursive lock prematurely released, pid=%d\n",
                                  ip->i_lockholder);
                  return (0);
          }
          ip->i_lockholder = 0;
          ip->i_flag &= ~(IN_LOCKED|IN_RECURSE);
          if (ip->i_flag & IN_WANTED) {
                  ip->i_flag &= ~IN_WANTED;
                  wakeup((caddr_t)ip);
          }
          return (0);
  }
  
  /*
   * Check for a locked inode.
   */
  int
  ufs_islocked(ap)
          struct vop_islocked_args /* {
                  struct vnode *a_vp;
          } */ *ap;
  {
  
          if (VTOI(ap->a_vp)->i_flag & IN_LOCKED)
                  return (1);
          return (0);
  }
  
  /*
   * Calculate the logical to physical mapping if not done already,
   * then call the device strategy routine.
   */
  int
  ufs_strategy(ap)
          struct vop_strategy_args /* {
                  struct buf *a_bp;
          } */ *ap;
  {
          register struct buf *bp = ap->a_bp;
          register struct vnode *vp = bp->b_vp;
          register struct inode *ip;
          int error;
  
          ip = VTOI(vp);
          if (vp->v_type == VBLK || vp->v_type == VCHR)
                  panic("ufs_strategy: spec");
          if (bp->b_blkno == bp->b_lblkno) {
                  error = VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL, NULL);
                  if (error) {
                          bp->b_error = error;
                          bp->b_flags |= B_ERROR;
                          biodone(bp);
                          return (error);
                  }
                  if ((long)bp->b_blkno == -1)
                          vfs_bio_clrbuf(bp);
          }
          if ((long)bp->b_blkno == -1) {
                  biodone(bp);
                  return (0);
          }
          vp = ip->i_devvp;
          bp->b_dev = vp->v_rdev;
          VOCALL (vp->v_op, VOFFSET(vop_strategy), ap);
          return (0);
  }
  
  /*
   * Print out the contents of an inode.
   */
  int
  ufs_print(ap)
          struct vop_print_args /* {
                  struct vnode *a_vp;
          } */ *ap;
  {
          register struct vnode *vp = ap->a_vp;
          register struct inode *ip = VTOI(vp);
  
          printf("tag VT_UFS, ino %ld, on dev %d, %d", ip->i_number,
                  major(ip->i_dev), minor(ip->i_dev));
          if (vp->v_type == VFIFO)
                  fifo_printinfo(vp);
          printf("%s\n", (ip->i_flag & IN_LOCKED) ? " (LOCKED)" : "");
          if (ip->i_lockholder == 0)
                  return (0);
          printf("\towner pid %lu", (u_long)ip->i_lockholder);
          if (ip->i_lockwaiter)
                  printf(" waiting pid %lu", (u_long)ip->i_lockwaiter);
          printf("\n");
          return (0);
  }
  
  /*
   * Read wrapper for special devices.
   */
  int
  ufsspec_read(ap)
          struct vop_read_args /* {
                  struct vnode *a_vp;
                  struct uio *a_uio;
                  int  a_ioflag;
                  struct ucred *a_cred;
          } */ *ap;
  {
  
          /*
           * Set access flag.
           */
          VTOI(ap->a_vp)->i_flag |= IN_ACCESS;
          return (VOCALL (spec_vnodeop_p, VOFFSET(vop_read), ap));
  }
  
  /*
   * Write wrapper for special devices.
   */
  int
  ufsspec_write(ap)
          struct vop_write_args /* {
                  struct vnode *a_vp;
                  struct uio *a_uio;
                  int  a_ioflag;
                  struct ucred *a_cred;
          } */ *ap;
  {
  
          /*
           * Set update and change flags.
           */
          VTOI(ap->a_vp)->i_flag |= IN_CHANGE | IN_UPDATE;
          return (VOCALL (spec_vnodeop_p, VOFFSET(vop_write), ap));
  }
  
  /*
   * Close wrapper for special devices.
   *
   * Update the times on the inode then do device close.
   */
  int
  ufsspec_close(ap)
          struct vop_close_args /* {
                  struct vnode *a_vp;
                  int  a_fflag;
                  struct ucred *a_cred;
                  struct proc *a_p;
          } */ *ap;
  {
          register struct inode *ip = VTOI(ap->a_vp);
  
          if (ap->a_vp->v_usecount > 1 && !(ip->i_flag & IN_LOCKED))
                  ITIMES(ip, &time, &time);
          return (VOCALL (spec_vnodeop_p, VOFFSET(vop_close), ap));
  }
  
  /*
   * Read wrapper for fifo's
   */
  int
  ufsfifo_read(ap)
          struct vop_read_args /* {
                  struct vnode *a_vp;
                  struct uio *a_uio;
                  int  a_ioflag;
                  struct ucred *a_cred;
          } */ *ap;
  {
          /*
           * Set access flag.
           */
          VTOI(ap->a_vp)->i_flag |= IN_ACCESS;
          return (VOCALL (fifo_vnodeop_p, VOFFSET(vop_read), ap));
  }
  
  /*
   * Write wrapper for fifo's.
   */
  int
  ufsfifo_write(ap)
          struct vop_write_args /* {
                  struct vnode *a_vp;
                  struct uio *a_uio;
                  int  a_ioflag;
                  struct ucred *a_cred;
          } */ *ap;
  {
          /*
           * Set update and change flags.
           */
          VTOI(ap->a_vp)->i_flag |= IN_CHANGE | IN_UPDATE;
          return (VOCALL (fifo_vnodeop_p, VOFFSET(vop_write), ap));
  }
  
  /*
   * Close wrapper for fifo's.
   *
   * Update the times on the inode then do device close.
   */
  int
  ufsfifo_close(ap)
          struct vop_close_args /* {
                  struct vnode *a_vp;
                  int  a_fflag;
                  struct ucred *a_cred;
                  struct proc *a_p;
          } */ *ap;
  {
          register struct inode *ip = VTOI(ap->a_vp);
  
          if (ap->a_vp->v_usecount > 1 && !(ip->i_flag & IN_LOCKED))
                  ITIMES(ip, &time, &time);
          return (VOCALL (fifo_vnodeop_p, VOFFSET(vop_close), ap));
  }
  
  /*
   * Return POSIX pathconf information applicable to ufs filesystems.
   */
  int
  ufs_pathconf(ap)
          struct vop_pathconf_args /* {
                  struct vnode *a_vp;
                  int a_name;
                  int *a_retval;
          } */ *ap;
  {
  
          switch (ap->a_name) {
          case _PC_LINK_MAX:
                  *ap->a_retval = LINK_MAX;
                  return (0);
          case _PC_NAME_MAX:
                  *ap->a_retval = NAME_MAX;
                  return (0);
          case _PC_PATH_MAX:
                  *ap->a_retval = PATH_MAX;
                  return (0);
          case _PC_PIPE_BUF:
                  *ap->a_retval = PIPE_BUF;
                  return (0);
          case _PC_CHOWN_RESTRICTED:
                  *ap->a_retval = 1;
                  return (0);
          case _PC_NO_TRUNC:
                  *ap->a_retval = 1;
                  return (0);
          default:
                  return (EINVAL);
          }
          /* NOTREACHED */
  }
  
  /*
   * Advisory record locking support
   */
  int
  ufs_advlock(ap)
          struct vop_advlock_args /* {
                  struct vnode *a_vp;
                  caddr_t  a_id;
                  int  a_op;
                  struct flock *a_fl;
                  int  a_flags;
          } */ *ap;
  {
          register struct inode *ip = VTOI(ap->a_vp);
  
          return (lf_advlock(ap, &(ip->i_lockf), ip->i_size));
  }
  
  /*
   * Initialize the vnode associated with a new inode, handle aliased
   * vnodes.
   */
  int
  ufs_vinit(mntp, specops, fifoops, vpp)
          struct mount *mntp;
          vop_t **specops;
          vop_t **fifoops;
          struct vnode **vpp;
  {
          struct inode *ip;
          struct vnode *vp, *nvp;
  
          vp = *vpp;
          ip = VTOI(vp);
          switch(vp->v_type = IFTOVT(ip->i_mode)) {
          case VCHR:
          case VBLK:
                  vp->v_op = specops;
                  nvp = checkalias(vp, ip->i_rdev, mntp);
                  if (nvp) {
                          /*
                           * Discard unneeded vnode, but save its inode.
                           */
                          ufs_ihashrem(ip);
                          VOP_UNLOCK(vp);
                          nvp->v_data = vp->v_data;
                          vp->v_data = NULL;
                          vp->v_op = spec_vnodeop_p;
                          vrele(vp);
                          vgone(vp);
                          /*
                           * Reinitialize aliased inode.
                           */
                          vp = nvp;
                          ip->i_vnode = vp;
                          ufs_ihashins(ip);
                  }
                  break;
          case VFIFO:
                  vp->v_op = fifoops;
                  break;
          default:
                  break;
  
          }
          if (ip->i_number == ROOTINO)
                  vp->v_flag |= VROOT;
          /*
           * Initialize modrev times
           */
          SETHIGH(ip->i_modrev, mono_time.tv_sec);
          SETLOW(ip->i_modrev, mono_time.tv_usec * 4294);
          *vpp = vp;
          return (0);
  }
  
  /*
   * Allocate a new inode.
   */
  int
  ufs_makeinode(mode, dvp, vpp, cnp)
          int mode;
          struct vnode *dvp;
          struct vnode **vpp;
          struct componentname *cnp;
  {
          register struct inode *ip, *pdir;
          struct timeval tv;
          struct vnode *tvp;
          int error;
  
          pdir = VTOI(dvp);
  #ifdef DIAGNOSTIC
          if ((cnp->cn_flags & HASBUF) == 0)
                  panic("ufs_makeinode: no name");
  #endif
          *vpp = NULL;
          if ((mode & IFMT) == 0)
                  mode |= IFREG;
  
          error = VOP_VALLOC(dvp, mode, cnp->cn_cred, &tvp);
          if (error) {
                  free(cnp->cn_pnbuf, M_NAMEI);
                  vput(dvp);
                  return (error);
          }
          ip = VTOI(tvp);
          ip->i_gid = pdir->i_gid;
          ip->i_uid = cnp->cn_cred->cr_uid;
  #ifdef QUOTA
          if ((error = getinoquota(ip)) ||
              (error = chkiq(ip, 1, cnp->cn_cred, 0))) {
                  free(cnp->cn_pnbuf, M_NAMEI);
                  VOP_VFREE(tvp, ip->i_number, mode);
                  vput(tvp);
                  vput(dvp);
                  return (error);
          }
  #endif
          ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
          ip->i_mode = mode;
          tvp->v_type = IFTOVT(mode);     /* Rest init'd in getnewvnode(). */
          ip->i_nlink = 1;
          if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred) &&
              suser(cnp->cn_cred, NULL))
                  ip->i_mode &= ~ISGID;
  
          /*
           * Make sure inode goes to disk before directory entry.
           */
          tv = time;
          error = VOP_UPDATE(tvp, &tv, &tv, 1);
          if (error)
                  goto bad;
  #ifdef EXT2FS
          if (IS_EXT2_VNODE(dvp)) {
                  error = ext2_direnter(ip, dvp, cnp);
          } else {
                  error = ufs_direnter(ip, dvp, cnp);
          }
  #else
          error = ufs_direnter(ip, dvp, cnp);
  #endif  /* EXT2FS */
          if (error)
                  goto bad;
  
          if ((cnp->cn_flags & SAVESTART) == 0)
                  FREE(cnp->cn_pnbuf, M_NAMEI);
          vput(dvp);
          *vpp = tvp;
          return (0);
  
  bad:
          /*
           * Write error occurred trying to update the inode
           * or the directory so must deallocate the inode.
           */
          free(cnp->cn_pnbuf, M_NAMEI);
          vput(dvp);
          ip->i_nlink = 0;
          ip->i_flag |= IN_CHANGE;
          vput(tvp);
          return (error);
  }

Cache object: 53033de3097fc02ab774852c0f0c3e3f