The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/fs/ext2fs/ext2_vnops.c

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    1 /*-
    2  *  modified for EXT2FS support in Lites 1.1
    3  *
    4  *  Aug 1995, Godmar Back (gback@cs.utah.edu)
    5  *  University of Utah, Department of Computer Science
    6  */
    7 /*-
    8  * Copyright (c) 1982, 1986, 1989, 1993
    9  *      The Regents of the University of California.  All rights reserved.
   10  * (c) UNIX System Laboratories, Inc.
   11  * All or some portions of this file are derived from material licensed
   12  * to the University of California by American Telephone and Telegraph
   13  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
   14  * the permission of UNIX System Laboratories, Inc.
   15  *
   16  * Redistribution and use in source and binary forms, with or without
   17  * modification, are permitted provided that the following conditions
   18  * are met:
   19  * 1. Redistributions of source code must retain the above copyright
   20  *    notice, this list of conditions and the following disclaimer.
   21  * 2. Redistributions in binary form must reproduce the above copyright
   22  *    notice, this list of conditions and the following disclaimer in the
   23  *    documentation and/or other materials provided with the distribution.
   24  * 4. Neither the name of the University nor the names of its contributors
   25  *    may be used to endorse or promote products derived from this software
   26  *    without specific prior written permission.
   27  *
   28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   38  * SUCH DAMAGE.
   39  *
   40  *      @(#)ufs_vnops.c 8.7 (Berkeley) 2/3/94
   41  *      @(#)ufs_vnops.c 8.27 (Berkeley) 5/27/95
   42  * $FreeBSD: releng/9.2/sys/fs/ext2fs/ext2_vnops.c 253218 2013-07-11 19:18:13Z pfg $
   43  */
   44 
   45 #include "opt_suiddir.h"
   46 
   47 #include <sys/param.h>
   48 #include <sys/systm.h>
   49 #include <sys/kernel.h>
   50 #include <sys/fcntl.h>
   51 #include <sys/filio.h>
   52 #include <sys/stat.h>
   53 #include <sys/bio.h>
   54 #include <sys/buf.h>
   55 #include <sys/endian.h>
   56 #include <sys/priv.h>
   57 #include <sys/mount.h>
   58 #include <sys/unistd.h>
   59 #include <sys/time.h>
   60 #include <sys/vnode.h>
   61 #include <sys/namei.h>
   62 #include <sys/lockf.h>
   63 #include <sys/event.h>
   64 #include <sys/conf.h>
   65 #include <sys/file.h>
   66 
   67 #include <vm/vm.h>
   68 #include <vm/vm_page.h>
   69 #include <vm/vm_object.h>
   70 #include <vm/vm_extern.h>
   71 #include <vm/vnode_pager.h>
   72 
   73 #include "opt_directio.h"
   74 
   75 #include <fs/fifofs/fifo.h>
   76 
   77 #include <ufs/ufs/dir.h>
   78 
   79 #include <fs/ext2fs/fs.h>
   80 #include <fs/ext2fs/inode.h>
   81 #include <fs/ext2fs/ext2_extern.h>
   82 #include <fs/ext2fs/ext2fs.h>
   83 #include <fs/ext2fs/ext2_dinode.h>
   84 #include <fs/ext2fs/ext2_dir.h>
   85 #include <fs/ext2fs/ext2_mount.h>
   86 
   87 static int ext2_makeinode(int mode, struct vnode *, struct vnode **, struct componentname *);
   88 static void ext2_itimes_locked(struct vnode *);
   89 
   90 static vop_access_t     ext2_access;
   91 static int ext2_chmod(struct vnode *, int, struct ucred *, struct thread *);
   92 static int ext2_chown(struct vnode *, uid_t, gid_t, struct ucred *,
   93     struct thread *);
   94 static vop_close_t      ext2_close;
   95 static vop_create_t     ext2_create;
   96 static vop_fsync_t      ext2_fsync;
   97 static vop_getattr_t    ext2_getattr;
   98 static vop_ioctl_t      ext2_ioctl;
   99 static vop_link_t       ext2_link;
  100 static vop_mkdir_t      ext2_mkdir;
  101 static vop_mknod_t      ext2_mknod;
  102 static vop_open_t       ext2_open;
  103 static vop_pathconf_t   ext2_pathconf;
  104 static vop_print_t      ext2_print;
  105 static vop_read_t       ext2_read;
  106 static vop_readlink_t   ext2_readlink;
  107 static vop_remove_t     ext2_remove;
  108 static vop_rename_t     ext2_rename;
  109 static vop_rmdir_t      ext2_rmdir;
  110 static vop_setattr_t    ext2_setattr;
  111 static vop_strategy_t   ext2_strategy;
  112 static vop_symlink_t    ext2_symlink;
  113 static vop_write_t      ext2_write;
  114 static vop_vptofh_t     ext2_vptofh;
  115 static vop_close_t      ext2fifo_close;
  116 static vop_kqfilter_t   ext2fifo_kqfilter;
  117 
  118 /* Global vfs data structures for ext2. */
  119 struct vop_vector ext2_vnodeops = {
  120         .vop_default =          &default_vnodeops,
  121         .vop_access =           ext2_access,
  122         .vop_bmap =             ext2_bmap,
  123         .vop_cachedlookup =     ext2_lookup,
  124         .vop_close =            ext2_close,
  125         .vop_create =           ext2_create,
  126         .vop_fsync =            ext2_fsync,
  127         .vop_getattr =          ext2_getattr,
  128         .vop_inactive =         ext2_inactive,
  129         .vop_ioctl =            ext2_ioctl,
  130         .vop_link =             ext2_link,
  131         .vop_lookup =           vfs_cache_lookup,
  132         .vop_mkdir =            ext2_mkdir,
  133         .vop_mknod =            ext2_mknod,
  134         .vop_open =             ext2_open,
  135         .vop_pathconf =         ext2_pathconf,
  136         .vop_poll =             vop_stdpoll,
  137         .vop_print =            ext2_print,
  138         .vop_read =             ext2_read,
  139         .vop_readdir =          ext2_readdir,
  140         .vop_readlink =         ext2_readlink,
  141         .vop_reallocblks =      ext2_reallocblks,
  142         .vop_reclaim =          ext2_reclaim,
  143         .vop_remove =           ext2_remove,
  144         .vop_rename =           ext2_rename,
  145         .vop_rmdir =            ext2_rmdir,
  146         .vop_setattr =          ext2_setattr,
  147         .vop_strategy =         ext2_strategy,
  148         .vop_symlink =          ext2_symlink,
  149         .vop_write =            ext2_write,
  150         .vop_vptofh =           ext2_vptofh,
  151 };
  152 
  153 struct vop_vector ext2_fifoops = {
  154         .vop_default =          &fifo_specops,
  155         .vop_access =           ext2_access,
  156         .vop_close =            ext2fifo_close,
  157         .vop_fsync =            ext2_fsync,
  158         .vop_getattr =          ext2_getattr,
  159         .vop_inactive =         ext2_inactive,
  160         .vop_kqfilter =         ext2fifo_kqfilter,
  161         .vop_print =            ext2_print,
  162         .vop_read =             VOP_PANIC,
  163         .vop_reclaim =          ext2_reclaim,
  164         .vop_setattr =          ext2_setattr,
  165         .vop_write =            VOP_PANIC,
  166         .vop_vptofh =           ext2_vptofh,
  167 };
  168 
  169 /*
  170  * A virgin directory (no blushing please).
  171  * Note that the type and namlen fields are reversed relative to ext2.
  172  * Also, we don't use `struct odirtemplate', since it would just cause
  173  * endianness problems.
  174  */
  175 static struct dirtemplate mastertemplate = {
  176         0, 12, 1, EXT2_FT_DIR, ".",
  177         0, DIRBLKSIZ - 12, 2, EXT2_FT_DIR, ".."
  178 };
  179 static struct dirtemplate omastertemplate = {
  180         0, 12, 1, EXT2_FT_UNKNOWN, ".",
  181         0, DIRBLKSIZ - 12, 2, EXT2_FT_UNKNOWN, ".."
  182 };
  183 
  184 static void
  185 ext2_itimes_locked(struct vnode *vp)
  186 {
  187         struct inode *ip;
  188         struct timespec ts;
  189 
  190         ASSERT_VI_LOCKED(vp, __func__); 
  191 
  192         ip = VTOI(vp);
  193         if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE)) == 0)
  194                 return;
  195         if ((vp->v_type == VBLK || vp->v_type == VCHR))
  196                 ip->i_flag |= IN_LAZYMOD;
  197         else
  198                 ip->i_flag |= IN_MODIFIED;
  199         if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
  200                 vfs_timestamp(&ts);
  201                 if (ip->i_flag & IN_ACCESS) {
  202                         ip->i_atime = ts.tv_sec;
  203                         ip->i_atimensec = ts.tv_nsec;
  204                 }
  205                 if (ip->i_flag & IN_UPDATE) {
  206                         ip->i_mtime = ts.tv_sec;
  207                         ip->i_mtimensec = ts.tv_nsec;
  208                         ip->i_modrev++;
  209                 }
  210                 if (ip->i_flag & IN_CHANGE) {
  211                         ip->i_ctime = ts.tv_sec;
  212                         ip->i_ctimensec = ts.tv_nsec;
  213                 }
  214         }
  215         ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
  216 }
  217 
  218 void
  219 ext2_itimes(struct vnode *vp)
  220 {
  221 
  222         VI_LOCK(vp);
  223         ext2_itimes_locked(vp);
  224         VI_UNLOCK(vp);
  225 }
  226 
  227 /*
  228  * Create a regular file
  229  */
  230 static int
  231 ext2_create(struct vop_create_args *ap)
  232 {
  233         int error;
  234 
  235         error =
  236             ext2_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
  237             ap->a_dvp, ap->a_vpp, ap->a_cnp);
  238         if (error)
  239                 return (error);
  240         return (0);
  241 }
  242 
  243 static int
  244 ext2_open(struct vop_open_args *ap)
  245 {
  246 
  247         if (ap->a_vp->v_type == VBLK || ap->a_vp->v_type == VCHR)
  248                 return (EOPNOTSUPP);
  249 
  250         /*
  251          * Files marked append-only must be opened for appending.
  252          */
  253         if ((VTOI(ap->a_vp)->i_flags & APPEND) &&
  254             (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
  255                 return (EPERM);
  256 
  257         vnode_create_vobject(ap->a_vp, VTOI(ap->a_vp)->i_size, ap->a_td);
  258 
  259         return (0);
  260 }
  261 
  262 /*
  263  * Close called.
  264  *
  265  * Update the times on the inode.
  266  */
  267 static int
  268 ext2_close(struct vop_close_args *ap)
  269 {
  270         struct vnode *vp = ap->a_vp;
  271 
  272         VI_LOCK(vp);
  273         if (vp->v_usecount > 1)
  274                 ext2_itimes_locked(vp);
  275         VI_UNLOCK(vp);
  276         return (0);
  277 }
  278 
  279 static int
  280 ext2_access(struct vop_access_args *ap)
  281 {
  282         struct vnode *vp = ap->a_vp;
  283         struct inode *ip = VTOI(vp);
  284         accmode_t accmode = ap->a_accmode;
  285         int error;
  286 
  287         if (vp->v_type == VBLK || vp->v_type == VCHR)
  288                 return (EOPNOTSUPP);
  289 
  290         /*
  291          * Disallow write attempts on read-only file systems;
  292          * unless the file is a socket, fifo, or a block or
  293          * character device resident on the file system.
  294          */
  295         if (accmode & VWRITE) {
  296                 switch (vp->v_type) {
  297                 case VDIR:
  298                 case VLNK:
  299                 case VREG:
  300                         if (vp->v_mount->mnt_flag & MNT_RDONLY)
  301                                 return (EROFS);
  302                         break;
  303                 default:
  304                         break;
  305                 }
  306         }
  307 
  308         /* If immutable bit set, nobody gets to write it. */
  309         if ((accmode & VWRITE) && (ip->i_flags & (SF_IMMUTABLE | SF_SNAPSHOT)))
  310                 return (EPERM);
  311 
  312         error = vaccess(vp->v_type, ip->i_mode, ip->i_uid, ip->i_gid,
  313             ap->a_accmode, ap->a_cred, NULL);
  314         return (error);
  315 }
  316 
  317 static int
  318 ext2_getattr(struct vop_getattr_args *ap)
  319 {
  320         struct vnode *vp = ap->a_vp;
  321         struct inode *ip = VTOI(vp);
  322         struct vattr *vap = ap->a_vap;
  323 
  324         ext2_itimes(vp);
  325         /*
  326          * Copy from inode table
  327          */
  328         vap->va_fsid = dev2udev(ip->i_devvp->v_rdev);
  329         vap->va_fileid = ip->i_number;
  330         vap->va_mode = ip->i_mode & ~IFMT;
  331         vap->va_nlink = ip->i_nlink;
  332         vap->va_uid = ip->i_uid;
  333         vap->va_gid = ip->i_gid;
  334         vap->va_rdev = ip->i_rdev;
  335         vap->va_size = ip->i_size;
  336         vap->va_atime.tv_sec = ip->i_atime;
  337         vap->va_atime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_atimensec : 0;
  338         vap->va_mtime.tv_sec = ip->i_mtime;
  339         vap->va_mtime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_mtimensec : 0;
  340         vap->va_ctime.tv_sec = ip->i_ctime;
  341         vap->va_ctime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_ctimensec : 0;
  342         if E2DI_HAS_XTIME(ip) {
  343                 vap->va_birthtime.tv_sec = ip->i_birthtime;
  344                 vap->va_birthtime.tv_nsec = ip->i_birthnsec;
  345         }
  346         vap->va_flags = ip->i_flags;
  347         vap->va_gen = ip->i_gen;
  348         vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
  349         vap->va_bytes = dbtob((u_quad_t)ip->i_blocks);
  350         vap->va_type = IFTOVT(ip->i_mode);
  351         vap->va_filerev = ip->i_modrev;
  352         return (0);
  353 }
  354 
  355 /*
  356  * Set attribute vnode op. called from several syscalls
  357  */
  358 static int
  359 ext2_setattr(struct vop_setattr_args *ap)
  360 {
  361         struct vattr *vap = ap->a_vap;
  362         struct vnode *vp = ap->a_vp;
  363         struct inode *ip = VTOI(vp);
  364         struct ucred *cred = ap->a_cred;
  365         struct thread *td = curthread;
  366         int error;
  367 
  368         /*
  369          * Check for unsettable attributes.
  370          */
  371         if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
  372             (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
  373             (vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
  374             ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
  375                 return (EINVAL);
  376         }
  377         if (vap->va_flags != VNOVAL) {
  378                 /* Disallow flags not supported by ext2fs. */
  379                 if(vap->va_flags & ~(SF_APPEND | SF_IMMUTABLE | UF_NODUMP))
  380                         return (EOPNOTSUPP);
  381 
  382                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  383                         return (EROFS);
  384                 /*
  385                  * Callers may only modify the file flags on objects they
  386                  * have VADMIN rights for.
  387                  */
  388                 if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
  389                         return (error);
  390                 /*
  391                  * Unprivileged processes and privileged processes in
  392                  * jail() are not permitted to unset system flags, or
  393                  * modify flags if any system flags are set.
  394                  * Privileged non-jail processes may not modify system flags
  395                  * if securelevel > 0 and any existing system flags are set.
  396                  */
  397                 if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) {
  398                         if (ip->i_flags &
  399                             (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) {
  400                                 error = securelevel_gt(cred, 0);
  401                                 if (error)
  402                                         return (error);
  403                         }
  404                         ip->i_flags = vap->va_flags;
  405                 } else {
  406                         if (ip->i_flags &
  407                             (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
  408                             (vap->va_flags & UF_SETTABLE) != vap->va_flags)
  409                                 return (EPERM);
  410                         ip->i_flags &= SF_SETTABLE;
  411                         ip->i_flags |= (vap->va_flags & UF_SETTABLE);
  412                 }
  413                 ip->i_flag |= IN_CHANGE;
  414                 if (ip->i_flags & (IMMUTABLE | APPEND))
  415                         return (0);
  416         }
  417         if (ip->i_flags & (IMMUTABLE | APPEND))
  418                 return (EPERM);
  419         /*
  420          * Go through the fields and update iff not VNOVAL.
  421          */
  422         if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
  423                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  424                         return (EROFS);
  425                 if ((error = ext2_chown(vp, vap->va_uid, vap->va_gid, cred,
  426                     td)) != 0)
  427                         return (error);
  428         }
  429         if (vap->va_size != VNOVAL) {
  430                 /*
  431                  * Disallow write attempts on read-only file systems;
  432                  * unless the file is a socket, fifo, or a block or
  433                  * character device resident on the file system.
  434                  */
  435                 switch (vp->v_type) {
  436                 case VDIR:
  437                         return (EISDIR);
  438                 case VLNK:
  439                 case VREG:
  440                         if (vp->v_mount->mnt_flag & MNT_RDONLY)
  441                                 return (EROFS);
  442                         break;
  443                 default:
  444                         break;
  445                 }
  446                 if ((error = ext2_truncate(vp, vap->va_size, 0, cred, td)) != 0)
  447                         return (error);
  448         }
  449         if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
  450                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  451                         return (EROFS);
  452                 /*
  453                  * From utimes(2):
  454                  * If times is NULL, ... The caller must be the owner of
  455                  * the file, have permission to write the file, or be the
  456                  * super-user.
  457                  * If times is non-NULL, ... The caller must be the owner of
  458                  * the file or be the super-user.
  459                  */
  460                 if ((error = VOP_ACCESS(vp, VADMIN, cred, td)) &&
  461                     ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
  462                     (error = VOP_ACCESS(vp, VWRITE, cred, td))))
  463                         return (error);
  464                 if (vap->va_atime.tv_sec != VNOVAL)
  465                         ip->i_flag |= IN_ACCESS;
  466                 if (vap->va_mtime.tv_sec != VNOVAL)
  467                         ip->i_flag |= IN_CHANGE | IN_UPDATE;
  468                 ext2_itimes(vp);
  469                 if (vap->va_atime.tv_sec != VNOVAL) {
  470                         ip->i_atime = vap->va_atime.tv_sec;
  471                         ip->i_atimensec = vap->va_atime.tv_nsec;
  472                 }
  473                 if (vap->va_mtime.tv_sec != VNOVAL) {
  474                         ip->i_mtime = vap->va_mtime.tv_sec;
  475                         ip->i_mtimensec = vap->va_mtime.tv_nsec;
  476                 }
  477                 ip->i_birthtime = vap->va_birthtime.tv_sec;
  478                 ip->i_birthnsec = vap->va_birthtime.tv_nsec;
  479                 error = ext2_update(vp, 0);
  480                 if (error)
  481                         return (error);
  482         }
  483         error = 0;
  484         if (vap->va_mode != (mode_t)VNOVAL) {
  485                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  486                         return (EROFS);
  487                 error = ext2_chmod(vp, (int)vap->va_mode, cred, td);
  488         }
  489         return (error);
  490 }
  491 
  492 /*
  493  * Change the mode on a file.
  494  * Inode must be locked before calling.
  495  */
  496 static int
  497 ext2_chmod(struct vnode *vp, int mode, struct ucred *cred, struct thread *td)
  498 {
  499         struct inode *ip = VTOI(vp);
  500         int error;
  501 
  502         /*
  503          * To modify the permissions on a file, must possess VADMIN
  504          * for that file.
  505          */
  506         if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
  507                 return (error);
  508         /*
  509          * Privileged processes may set the sticky bit on non-directories,
  510          * as well as set the setgid bit on a file with a group that the
  511          * process is not a member of.
  512          */
  513         if (vp->v_type != VDIR && (mode & S_ISTXT)) {
  514                 error = priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0);
  515                 if (error)
  516                         return (EFTYPE);
  517         }
  518         if (!groupmember(ip->i_gid, cred) && (mode & ISGID)) {
  519                 error = priv_check_cred(cred, PRIV_VFS_SETGID, 0);
  520                 if (error)
  521                         return (error);
  522         }
  523         ip->i_mode &= ~ALLPERMS;
  524         ip->i_mode |= (mode & ALLPERMS);
  525         ip->i_flag |= IN_CHANGE;
  526         return (0);
  527 }
  528 
  529 /*
  530  * Perform chown operation on inode ip;
  531  * inode must be locked prior to call.
  532  */
  533 static int
  534 ext2_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
  535     struct thread *td)
  536 {
  537         struct inode *ip = VTOI(vp);
  538         uid_t ouid;
  539         gid_t ogid;
  540         int error = 0;
  541 
  542         if (uid == (uid_t)VNOVAL)
  543                 uid = ip->i_uid;
  544         if (gid == (gid_t)VNOVAL)
  545                 gid = ip->i_gid;
  546         /*
  547          * To modify the ownership of a file, must possess VADMIN
  548          * for that file.
  549          */
  550         if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
  551                 return (error);
  552         /*
  553          * To change the owner of a file, or change the group of a file
  554          * to a group of which we are not a member, the caller must
  555          * have privilege.
  556          */
  557         if (uid != ip->i_uid || (gid != ip->i_gid &&
  558             !groupmember(gid, cred))) {
  559                 error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0);
  560                 if (error)
  561                         return (error);
  562         }
  563         ogid = ip->i_gid;
  564         ouid = ip->i_uid;
  565         ip->i_gid = gid;
  566         ip->i_uid = uid;
  567         ip->i_flag |= IN_CHANGE;
  568         if ((ip->i_mode & (ISUID | ISGID)) && (ouid != uid || ogid != gid)) {
  569                 if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0) != 0)
  570                         ip->i_mode &= ~(ISUID | ISGID);
  571         }
  572         return (0);
  573 }
  574 
  575 /*
  576  * Synch an open file.
  577  */
  578 /* ARGSUSED */
  579 static int
  580 ext2_fsync(struct vop_fsync_args *ap)
  581 {
  582         /*
  583          * Flush all dirty buffers associated with a vnode.
  584          */
  585 
  586         vop_stdfsync(ap);
  587 
  588         return (ext2_update(ap->a_vp, ap->a_waitfor == MNT_WAIT));
  589 }
  590 
  591 /*
  592  * Mknod vnode call
  593  */
  594 /* ARGSUSED */
  595 static int
  596 ext2_mknod(struct vop_mknod_args *ap)
  597 {
  598         struct vattr *vap = ap->a_vap;
  599         struct vnode **vpp = ap->a_vpp;
  600         struct inode *ip;
  601         ino_t ino;
  602         int error;
  603 
  604         error = ext2_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
  605             ap->a_dvp, vpp, ap->a_cnp);
  606         if (error)
  607                 return (error);
  608         ip = VTOI(*vpp);
  609         ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
  610         if (vap->va_rdev != VNOVAL) {
  611                 /*
  612                  * Want to be able to use this to make badblock
  613                  * inodes, so don't truncate the dev number.
  614                  */
  615                 ip->i_rdev = vap->va_rdev;
  616         }
  617         /*
  618          * Remove inode, then reload it through VFS_VGET so it is
  619          * checked to see if it is an alias of an existing entry in
  620          * the inode cache.      XXX I don't believe this is necessary now.
  621          */
  622         (*vpp)->v_type = VNON;
  623         ino = ip->i_number;     /* Save this before vgone() invalidates ip. */
  624         vgone(*vpp);
  625         vput(*vpp);
  626         error = VFS_VGET(ap->a_dvp->v_mount, ino, LK_EXCLUSIVE, vpp);
  627         if (error) {
  628                 *vpp = NULL;
  629                 return (error);
  630         }
  631         return (0);
  632 }
  633 
  634 static int
  635 ext2_remove(struct vop_remove_args *ap)
  636 {
  637         struct inode *ip;
  638         struct vnode *vp = ap->a_vp;
  639         struct vnode *dvp = ap->a_dvp;
  640         int error;
  641 
  642         ip = VTOI(vp);
  643         if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
  644             (VTOI(dvp)->i_flags & APPEND)) {
  645                 error = EPERM;
  646                 goto out;
  647         }
  648         error = ext2_dirremove(dvp, ap->a_cnp);
  649         if (error == 0) {
  650                 ip->i_nlink--;
  651                 ip->i_flag |= IN_CHANGE;
  652         }
  653 out:
  654         return (error);
  655 }
  656 
  657 /*
  658  * link vnode call
  659  */
  660 static int
  661 ext2_link(struct vop_link_args *ap)
  662 {
  663         struct vnode *vp = ap->a_vp;
  664         struct vnode *tdvp = ap->a_tdvp;
  665         struct componentname *cnp = ap->a_cnp;
  666         struct inode *ip;
  667         int error;
  668 
  669 #ifdef INVARIANTS
  670         if ((cnp->cn_flags & HASBUF) == 0)
  671                 panic("ext2_link: no name");
  672 #endif
  673         if (tdvp->v_mount != vp->v_mount) {
  674                 error = EXDEV;
  675                 goto out;
  676         }
  677         ip = VTOI(vp);
  678         if ((nlink_t)ip->i_nlink >= EXT2_LINK_MAX) {
  679                 error = EMLINK;
  680                 goto out;
  681         }
  682         if (ip->i_flags & (IMMUTABLE | APPEND)) {
  683                 error = EPERM;
  684                 goto out;
  685         }
  686         ip->i_nlink++;
  687         ip->i_flag |= IN_CHANGE;
  688         error = ext2_update(vp, !DOINGASYNC(vp));
  689         if (!error)
  690                 error = ext2_direnter(ip, tdvp, cnp);
  691         if (error) {
  692                 ip->i_nlink--;
  693                 ip->i_flag |= IN_CHANGE;
  694         }
  695 out:
  696         return (error);
  697 }
  698 
  699 /*
  700  * Rename system call.
  701  *      rename("foo", "bar");
  702  * is essentially
  703  *      unlink("bar");
  704  *      link("foo", "bar");
  705  *      unlink("foo");
  706  * but ``atomically''.  Can't do full commit without saving state in the
  707  * inode on disk which isn't feasible at this time.  Best we can do is
  708  * always guarantee the target exists.
  709  *
  710  * Basic algorithm is:
  711  *
  712  * 1) Bump link count on source while we're linking it to the
  713  *    target.  This also ensure the inode won't be deleted out
  714  *    from underneath us while we work (it may be truncated by
  715  *    a concurrent `trunc' or `open' for creation).
  716  * 2) Link source to destination.  If destination already exists,
  717  *    delete it first.
  718  * 3) Unlink source reference to inode if still around. If a
  719  *    directory was moved and the parent of the destination
  720  *    is different from the source, patch the ".." entry in the
  721  *    directory.
  722  */
  723 static int
  724 ext2_rename(struct vop_rename_args *ap)
  725 {
  726         struct vnode *tvp = ap->a_tvp;
  727         struct vnode *tdvp = ap->a_tdvp;
  728         struct vnode *fvp = ap->a_fvp;
  729         struct vnode *fdvp = ap->a_fdvp;
  730         struct componentname *tcnp = ap->a_tcnp;
  731         struct componentname *fcnp = ap->a_fcnp;
  732         struct inode *ip, *xp, *dp;
  733         struct dirtemplate dirbuf;
  734         int doingdirectory = 0, oldparent = 0, newparent = 0;
  735         int error = 0;
  736         u_char namlen;
  737 
  738 #ifdef INVARIANTS
  739         if ((tcnp->cn_flags & HASBUF) == 0 ||
  740             (fcnp->cn_flags & HASBUF) == 0)
  741                 panic("ext2_rename: no name");
  742 #endif
  743         /*
  744          * Check for cross-device rename.
  745          */
  746         if ((fvp->v_mount != tdvp->v_mount) ||
  747             (tvp && (fvp->v_mount != tvp->v_mount))) {
  748                 error = EXDEV;
  749 abortit:
  750                 if (tdvp == tvp)
  751                         vrele(tdvp);
  752                 else
  753                         vput(tdvp);
  754                 if (tvp)
  755                         vput(tvp);
  756                 vrele(fdvp);
  757                 vrele(fvp);
  758                 return (error);
  759         }
  760 
  761         if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
  762             (VTOI(tdvp)->i_flags & APPEND))) {
  763                 error = EPERM;
  764                 goto abortit;
  765         }
  766 
  767         /*
  768          * Renaming a file to itself has no effect.  The upper layers should
  769          * not call us in that case.  Temporarily just warn if they do.
  770          */
  771         if (fvp == tvp) {
  772                 printf("ext2_rename: fvp == tvp (can't happen)\n");
  773                 error = 0;
  774                 goto abortit;
  775         }
  776 
  777         if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
  778                 goto abortit;
  779         dp = VTOI(fdvp);
  780         ip = VTOI(fvp);
  781         if (ip->i_nlink >= EXT2_LINK_MAX) {
  782                 VOP_UNLOCK(fvp, 0);
  783                 error = EMLINK;
  784                 goto abortit;
  785         }
  786         if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
  787             || (dp->i_flags & APPEND)) {
  788                 VOP_UNLOCK(fvp, 0);
  789                 error = EPERM;
  790                 goto abortit;
  791         }
  792         if ((ip->i_mode & IFMT) == IFDIR) {
  793                 /*
  794                  * Avoid ".", "..", and aliases of "." for obvious reasons.
  795                  */
  796                 if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
  797                     dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & ISDOTDOT ||
  798                     (ip->i_flag & IN_RENAME)) {
  799                         VOP_UNLOCK(fvp, 0);
  800                         error = EINVAL;
  801                         goto abortit;
  802                 }
  803                 ip->i_flag |= IN_RENAME;
  804                 oldparent = dp->i_number;
  805                 doingdirectory++;
  806         }
  807         vrele(fdvp);
  808 
  809         /*
  810          * When the target exists, both the directory
  811          * and target vnodes are returned locked.
  812          */
  813         dp = VTOI(tdvp);
  814         xp = NULL;
  815         if (tvp)
  816                 xp = VTOI(tvp);
  817 
  818         /*
  819          * 1) Bump link count while we're moving stuff
  820          *    around.  If we crash somewhere before
  821          *    completing our work, the link count
  822          *    may be wrong, but correctable.
  823          */
  824         ip->i_nlink++;
  825         ip->i_flag |= IN_CHANGE;
  826         if ((error = ext2_update(fvp, !DOINGASYNC(fvp))) != 0) {
  827                 VOP_UNLOCK(fvp, 0);
  828                 goto bad;
  829         }
  830 
  831         /*
  832          * If ".." must be changed (ie the directory gets a new
  833          * parent) then the source directory must not be in the
  834          * directory hierarchy above the target, as this would
  835          * orphan everything below the source directory. Also
  836          * the user must have write permission in the source so
  837          * as to be able to change "..". We must repeat the call
  838          * to namei, as the parent directory is unlocked by the
  839          * call to checkpath().
  840          */
  841         error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_thread);
  842         VOP_UNLOCK(fvp, 0);
  843         if (oldparent != dp->i_number)
  844                 newparent = dp->i_number;
  845         if (doingdirectory && newparent) {
  846                 if (error)      /* write access check above */
  847                         goto bad;
  848                 if (xp != NULL)
  849                         vput(tvp);
  850                 error = ext2_checkpath(ip, dp, tcnp->cn_cred);
  851                 if (error)
  852                         goto out;
  853                 VREF(tdvp);
  854                 error = relookup(tdvp, &tvp, tcnp);
  855                 if (error)
  856                         goto out;
  857                 vrele(tdvp);
  858                 dp = VTOI(tdvp);
  859                 xp = NULL;
  860                 if (tvp)
  861                         xp = VTOI(tvp);
  862         }
  863         /*
  864          * 2) If target doesn't exist, link the target
  865          *    to the source and unlink the source.
  866          *    Otherwise, rewrite the target directory
  867          *    entry to reference the source inode and
  868          *    expunge the original entry's existence.
  869          */
  870         if (xp == NULL) {
  871                 if (dp->i_devvp != ip->i_devvp)
  872                         panic("ext2_rename: EXDEV");
  873                 /*
  874                  * Account for ".." in new directory.
  875                  * When source and destination have the same
  876                  * parent we don't fool with the link count.
  877                  */
  878                 if (doingdirectory && newparent) {
  879                         if ((nlink_t)dp->i_nlink >= EXT2_LINK_MAX) {
  880                                 error = EMLINK;
  881                                 goto bad;
  882                         }
  883                         dp->i_nlink++;
  884                         dp->i_flag |= IN_CHANGE;
  885                         error = ext2_update(tdvp, !DOINGASYNC(tdvp));
  886                         if (error)
  887                                 goto bad;
  888                 }
  889                 error = ext2_direnter(ip, tdvp, tcnp);
  890                 if (error) {
  891                         if (doingdirectory && newparent) {
  892                                 dp->i_nlink--;
  893                                 dp->i_flag |= IN_CHANGE;
  894                                 (void)ext2_update(tdvp, 1);
  895                         }
  896                         goto bad;
  897                 }
  898                 vput(tdvp);
  899         } else {
  900                 if (xp->i_devvp != dp->i_devvp || xp->i_devvp != ip->i_devvp)
  901                        panic("ext2_rename: EXDEV");
  902                 /*
  903                  * Short circuit rename(foo, foo).
  904                  */
  905                 if (xp->i_number == ip->i_number)
  906                         panic("ext2_rename: same file");
  907                 /*
  908                  * If the parent directory is "sticky", then the user must
  909                  * own the parent directory, or the destination of the rename,
  910                  * otherwise the destination may not be changed (except by
  911                  * root). This implements append-only directories.
  912                  */
  913                 if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
  914                     tcnp->cn_cred->cr_uid != dp->i_uid &&
  915                     xp->i_uid != tcnp->cn_cred->cr_uid) {
  916                         error = EPERM;
  917                         goto bad;
  918                 }
  919                 /*
  920                  * Target must be empty if a directory and have no links
  921                  * to it. Also, ensure source and target are compatible
  922                  * (both directories, or both not directories).
  923                  */
  924                 if ((xp->i_mode&IFMT) == IFDIR) {
  925                         if (! ext2_dirempty(xp, dp->i_number, tcnp->cn_cred) || 
  926                             xp->i_nlink > 2) {
  927                                 error = ENOTEMPTY;
  928                                 goto bad;
  929                         }
  930                         if (!doingdirectory) {
  931                                 error = ENOTDIR;
  932                                 goto bad;
  933                         }
  934                         cache_purge(tdvp);
  935                 } else if (doingdirectory) {
  936                         error = EISDIR;
  937                         goto bad;
  938                 }
  939                 error = ext2_dirrewrite(dp, ip, tcnp);
  940                 if (error)
  941                         goto bad;
  942                 /*
  943                  * If the target directory is in the same
  944                  * directory as the source directory,
  945                  * decrement the link count on the parent
  946                  * of the target directory.
  947                  */
  948                 if (doingdirectory && !newparent) {
  949                        dp->i_nlink--;
  950                        dp->i_flag |= IN_CHANGE;
  951                 }
  952                 vput(tdvp);
  953                 /*
  954                  * Adjust the link count of the target to
  955                  * reflect the dirrewrite above.  If this is
  956                  * a directory it is empty and there are
  957                  * no links to it, so we can squash the inode and
  958                  * any space associated with it.  We disallowed
  959                  * renaming over top of a directory with links to
  960                  * it above, as the remaining link would point to
  961                  * a directory without "." or ".." entries.
  962                  */
  963                 xp->i_nlink--;
  964                 if (doingdirectory) {
  965                         if (--xp->i_nlink != 0)
  966                                 panic("ext2_rename: linked directory");
  967                         error = ext2_truncate(tvp, (off_t)0, IO_SYNC,
  968                             tcnp->cn_cred, tcnp->cn_thread);
  969                 }
  970                 xp->i_flag |= IN_CHANGE;
  971                 vput(tvp);
  972                 xp = NULL;
  973         }
  974 
  975         /*
  976          * 3) Unlink the source.
  977          */
  978         fcnp->cn_flags &= ~MODMASK;
  979         fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
  980         VREF(fdvp);
  981         error = relookup(fdvp, &fvp, fcnp);
  982         if (error == 0)
  983                 vrele(fdvp);
  984         if (fvp != NULL) {
  985                 xp = VTOI(fvp);
  986                 dp = VTOI(fdvp);
  987         } else {
  988                 /*
  989                  * From name has disappeared.
  990                  */
  991                 if (doingdirectory)
  992                         panic("ext2_rename: lost dir entry");
  993                 vrele(ap->a_fvp);
  994                 return (0);
  995         }
  996         /*
  997          * Ensure that the directory entry still exists and has not
  998          * changed while the new name has been entered. If the source is
  999          * a file then the entry may have been unlinked or renamed. In
 1000          * either case there is no further work to be done. If the source
 1001          * is a directory then it cannot have been rmdir'ed; its link
 1002          * count of three would cause a rmdir to fail with ENOTEMPTY.
 1003          * The IN_RENAME flag ensures that it cannot be moved by another
 1004          * rename.
 1005          */
 1006         if (xp != ip) {
 1007                 if (doingdirectory)
 1008                         panic("ext2_rename: lost dir entry");
 1009         } else {
 1010                 /*
 1011                  * If the source is a directory with a
 1012                  * new parent, the link count of the old
 1013                  * parent directory must be decremented
 1014                  * and ".." set to point to the new parent.
 1015                  */
 1016                 if (doingdirectory && newparent) {
 1017                         dp->i_nlink--;
 1018                         dp->i_flag |= IN_CHANGE;
 1019                         error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
 1020                                 sizeof(struct dirtemplate), (off_t)0,
 1021                                 UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
 1022                                 tcnp->cn_cred, NOCRED, NULL, NULL);
 1023                         if (error == 0) {
 1024                                 /* Like ufs little-endian: */
 1025                                 namlen = dirbuf.dotdot_type;
 1026                                 if (namlen != 2 ||
 1027                                     dirbuf.dotdot_name[0] != '.' ||
 1028                                     dirbuf.dotdot_name[1] != '.') {
 1029                                         ext2_dirbad(xp, (doff_t)12,
 1030                                             "rename: mangled dir");
 1031                                 } else {
 1032                                         dirbuf.dotdot_ino = newparent;
 1033                                         (void) vn_rdwr(UIO_WRITE, fvp,
 1034                                             (caddr_t)&dirbuf,
 1035                                             sizeof(struct dirtemplate),
 1036                                             (off_t)0, UIO_SYSSPACE,
 1037                                             IO_NODELOCKED | IO_SYNC |
 1038                                             IO_NOMACCHECK, tcnp->cn_cred,
 1039                                             NOCRED, NULL, NULL);
 1040                                         cache_purge(fdvp);
 1041                                 }
 1042                         }
 1043                 }
 1044                 error = ext2_dirremove(fdvp, fcnp);
 1045                 if (!error) {
 1046                         xp->i_nlink--;
 1047                         xp->i_flag |= IN_CHANGE;
 1048                 }
 1049                 xp->i_flag &= ~IN_RENAME;
 1050         }
 1051         if (dp)
 1052                 vput(fdvp);
 1053         if (xp)
 1054                 vput(fvp);
 1055         vrele(ap->a_fvp);
 1056         return (error);
 1057 
 1058 bad:
 1059         if (xp)
 1060                 vput(ITOV(xp));
 1061         vput(ITOV(dp));
 1062 out:
 1063         if (doingdirectory)
 1064                 ip->i_flag &= ~IN_RENAME;
 1065         if (vn_lock(fvp, LK_EXCLUSIVE) == 0) {
 1066                 ip->i_nlink--;
 1067                 ip->i_flag |= IN_CHANGE;
 1068                 ip->i_flag &= ~IN_RENAME;
 1069                 vput(fvp);
 1070         } else
 1071                 vrele(fvp);
 1072         return (error);
 1073 }
 1074 
 1075 /*
 1076  * Mkdir system call
 1077  */
 1078 static int
 1079 ext2_mkdir(struct vop_mkdir_args *ap)
 1080 {
 1081         struct vnode *dvp = ap->a_dvp;
 1082         struct vattr *vap = ap->a_vap;
 1083         struct componentname *cnp = ap->a_cnp;
 1084         struct inode *ip, *dp;
 1085         struct vnode *tvp;
 1086         struct dirtemplate dirtemplate, *dtp;
 1087         int error, dmode;
 1088 
 1089 #ifdef INVARIANTS
 1090         if ((cnp->cn_flags & HASBUF) == 0)
 1091                 panic("ext2_mkdir: no name");
 1092 #endif
 1093         dp = VTOI(dvp);
 1094         if ((nlink_t)dp->i_nlink >= EXT2_LINK_MAX) {
 1095                 error = EMLINK;
 1096                 goto out;
 1097         }
 1098         dmode = vap->va_mode & 0777;
 1099         dmode |= IFDIR;
 1100         /*
 1101          * Must simulate part of ext2_makeinode here to acquire the inode,
 1102          * but not have it entered in the parent directory. The entry is
 1103          * made later after writing "." and ".." entries.
 1104          */
 1105         error = ext2_valloc(dvp, dmode, cnp->cn_cred, &tvp);
 1106         if (error)
 1107                 goto out;
 1108         ip = VTOI(tvp);
 1109         ip->i_gid = dp->i_gid;
 1110 #ifdef SUIDDIR
 1111         {
 1112                 /*
 1113                  * if we are hacking owners here, (only do this where told to)
 1114                  * and we are not giving it TOO root, (would subvert quotas)
 1115                  * then go ahead and give it to the other user.
 1116                  * The new directory also inherits the SUID bit. 
 1117                  * If user's UID and dir UID are the same,
 1118                  * 'give it away' so that the SUID is still forced on.
 1119                  */
 1120                 if ( (dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
 1121                    (dp->i_mode & ISUID) && dp->i_uid) {
 1122                         dmode |= ISUID;
 1123                         ip->i_uid = dp->i_uid;
 1124                 } else {
 1125                         ip->i_uid = cnp->cn_cred->cr_uid;
 1126                 }
 1127         }
 1128 #else
 1129         ip->i_uid = cnp->cn_cred->cr_uid;
 1130 #endif
 1131         ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
 1132         ip->i_mode = dmode;
 1133         tvp->v_type = VDIR;     /* Rest init'd in getnewvnode(). */
 1134         ip->i_nlink = 2;
 1135         if (cnp->cn_flags & ISWHITEOUT)
 1136                 ip->i_flags |= UF_OPAQUE;
 1137         error = ext2_update(tvp, 1);
 1138 
 1139         /*
 1140          * Bump link count in parent directory
 1141          * to reflect work done below.  Should
 1142          * be done before reference is created
 1143          * so reparation is possible if we crash.
 1144          */
 1145         dp->i_nlink++;
 1146         dp->i_flag |= IN_CHANGE;
 1147         error = ext2_update(dvp, !DOINGASYNC(dvp));
 1148         if (error)
 1149                 goto bad;
 1150 
 1151         /* Initialize directory with "." and ".." from static template. */
 1152         if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs,
 1153             EXT2F_INCOMPAT_FTYPE))
 1154                 dtp = &mastertemplate;
 1155         else
 1156                 dtp = &omastertemplate;
 1157         dirtemplate = *dtp;
 1158         dirtemplate.dot_ino = ip->i_number;
 1159         dirtemplate.dotdot_ino = dp->i_number;
 1160         /* note that in ext2 DIRBLKSIZ == blocksize, not DEV_BSIZE 
 1161          * so let's just redefine it - for this function only
 1162          */
 1163 #undef  DIRBLKSIZ 
 1164 #define DIRBLKSIZ  VTOI(dvp)->i_e2fs->e2fs_bsize
 1165         dirtemplate.dotdot_reclen = DIRBLKSIZ - 12;
 1166         error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)&dirtemplate,
 1167             sizeof(dirtemplate), (off_t)0, UIO_SYSSPACE,
 1168             IO_NODELOCKED | IO_SYNC | IO_NOMACCHECK, cnp->cn_cred, NOCRED,
 1169             NULL, NULL);
 1170         if (error) {
 1171                 dp->i_nlink--;
 1172                 dp->i_flag |= IN_CHANGE;
 1173                 goto bad;
 1174         }
 1175         if (DIRBLKSIZ > VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
 1176                 /* XXX should grow with balloc() */
 1177                 panic("ext2_mkdir: blksize");
 1178         else {
 1179                 ip->i_size = DIRBLKSIZ;
 1180                 ip->i_flag |= IN_CHANGE;
 1181         }
 1182 
 1183         /* Directory set up, now install its entry in the parent directory. */
 1184         error = ext2_direnter(ip, dvp, cnp);
 1185         if (error) {
 1186                 dp->i_nlink--;
 1187                 dp->i_flag |= IN_CHANGE;
 1188         }
 1189 bad:
 1190         /*
 1191          * No need to do an explicit VOP_TRUNCATE here, vrele will do this
 1192          * for us because we set the link count to 0.
 1193          */
 1194         if (error) {
 1195                 ip->i_nlink = 0;
 1196                 ip->i_flag |= IN_CHANGE;
 1197                 vput(tvp);
 1198         } else
 1199                 *ap->a_vpp = tvp;
 1200 out:
 1201         return (error);
 1202 #undef  DIRBLKSIZ
 1203 #define DIRBLKSIZ  DEV_BSIZE
 1204 }
 1205 
 1206 /*
 1207  * Rmdir system call.
 1208  */
 1209 static int
 1210 ext2_rmdir(struct vop_rmdir_args *ap)
 1211 {
 1212         struct vnode *vp = ap->a_vp;
 1213         struct vnode *dvp = ap->a_dvp;
 1214         struct componentname *cnp = ap->a_cnp;
 1215         struct inode *ip, *dp;
 1216         int error;
 1217 
 1218         ip = VTOI(vp);
 1219         dp = VTOI(dvp);
 1220 
 1221         /*
 1222          * Verify the directory is empty (and valid).
 1223          * (Rmdir ".." won't be valid since
 1224          *  ".." will contain a reference to
 1225          *  the current directory and thus be
 1226          *  non-empty.)
 1227          */
 1228         error = 0;
 1229         if (ip->i_nlink != 2 || !ext2_dirempty(ip, dp->i_number, cnp->cn_cred)) {
 1230                 error = ENOTEMPTY;
 1231                 goto out;
 1232         }
 1233         if ((dp->i_flags & APPEND)
 1234             || (ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
 1235                 error = EPERM;
 1236                 goto out;
 1237         }
 1238         /*
 1239          * Delete reference to directory before purging
 1240          * inode.  If we crash in between, the directory
 1241          * will be reattached to lost+found,
 1242          */
 1243         error = ext2_dirremove(dvp, cnp);
 1244         if (error)
 1245                 goto out;
 1246         dp->i_nlink--;
 1247         dp->i_flag |= IN_CHANGE;
 1248         cache_purge(dvp);
 1249         VOP_UNLOCK(dvp, 0);
 1250         /*
 1251          * Truncate inode.  The only stuff left
 1252          * in the directory is "." and "..".  The
 1253          * "." reference is inconsequential since
 1254          * we're quashing it.  The ".." reference
 1255          * has already been adjusted above.  We've
 1256          * removed the "." reference and the reference
 1257          * in the parent directory, but there may be
 1258          * other hard links so decrement by 2 and
 1259          * worry about them later.
 1260          */
 1261         ip->i_nlink -= 2;
 1262         error = ext2_truncate(vp, (off_t)0, IO_SYNC, cnp->cn_cred,
 1263             cnp->cn_thread);
 1264         cache_purge(ITOV(ip));
 1265         if (vn_lock(dvp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
 1266                 VOP_UNLOCK(vp, 0);
 1267                 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
 1268                 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 1269         }
 1270 out:
 1271         return (error);
 1272 }
 1273 
 1274 /*
 1275  * symlink -- make a symbolic link
 1276  */
 1277 static int
 1278 ext2_symlink(struct vop_symlink_args *ap)
 1279 {
 1280         struct vnode *vp, **vpp = ap->a_vpp;
 1281         struct inode *ip;
 1282         int len, error;
 1283 
 1284         error = ext2_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
 1285             vpp, ap->a_cnp);
 1286         if (error)
 1287                 return (error);
 1288         vp = *vpp;
 1289         len = strlen(ap->a_target);
 1290         if (len < vp->v_mount->mnt_maxsymlinklen) {
 1291                 ip = VTOI(vp);
 1292                 bcopy(ap->a_target, (char *)ip->i_shortlink, len);
 1293                 ip->i_size = len;
 1294                 ip->i_flag |= IN_CHANGE | IN_UPDATE;
 1295         } else
 1296                 error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
 1297                     UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
 1298                     ap->a_cnp->cn_cred, NOCRED, NULL, NULL);
 1299         if (error)
 1300                 vput(vp);
 1301         return (error);
 1302 }
 1303 
 1304 /*
 1305  * Return target name of a symbolic link
 1306  */
 1307 static int
 1308 ext2_readlink(struct vop_readlink_args *ap)
 1309 {
 1310         struct vnode *vp = ap->a_vp;
 1311         struct inode *ip = VTOI(vp);
 1312         int isize;
 1313 
 1314         isize = ip->i_size;
 1315         if (isize < vp->v_mount->mnt_maxsymlinklen) {
 1316                 uiomove((char *)ip->i_shortlink, isize, ap->a_uio);
 1317                 return (0);
 1318         }
 1319         return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
 1320 }
 1321 
 1322 /*
 1323  * Calculate the logical to physical mapping if not done already,
 1324  * then call the device strategy routine.
 1325  *
 1326  * In order to be able to swap to a file, the ext2_bmaparray() operation may not
 1327  * deadlock on memory.  See ext2_bmap() for details.
 1328  */
 1329 static int
 1330 ext2_strategy(struct vop_strategy_args *ap)
 1331 {
 1332         struct buf *bp = ap->a_bp;
 1333         struct vnode *vp = ap->a_vp;
 1334         struct inode *ip;
 1335         struct bufobj *bo;
 1336         int32_t blkno;
 1337         int error;
 1338 
 1339         ip = VTOI(vp);
 1340         if (vp->v_type == VBLK || vp->v_type == VCHR)
 1341                 panic("ext2_strategy: spec");
 1342         if (bp->b_blkno == bp->b_lblkno) {
 1343                 error = ext2_bmaparray(vp, bp->b_lblkno, &blkno, NULL, NULL);
 1344                 bp->b_blkno = blkno;
 1345                 if (error) {
 1346                         bp->b_error = error;
 1347                         bp->b_ioflags |= BIO_ERROR;
 1348                         bufdone(bp);
 1349                         return (0);
 1350                 }
 1351                 if ((long)bp->b_blkno == -1)
 1352                         vfs_bio_clrbuf(bp);
 1353         }
 1354         if ((long)bp->b_blkno == -1) {
 1355                 bufdone(bp);
 1356                 return (0);
 1357         }
 1358         bp->b_iooffset = dbtob(bp->b_blkno);
 1359         bo = VFSTOEXT2(vp->v_mount)->um_bo;
 1360         BO_STRATEGY(bo, bp);
 1361         return (0);
 1362 }
 1363 
 1364 /*
 1365  * Print out the contents of an inode.
 1366  */
 1367 static int
 1368 ext2_print(struct vop_print_args *ap)
 1369 {
 1370         struct vnode *vp = ap->a_vp;
 1371         struct inode *ip = VTOI(vp);
 1372 
 1373         vn_printf(ip->i_devvp, "\tino %lu", (u_long)ip->i_number);
 1374         if (vp->v_type == VFIFO)
 1375                 fifo_printinfo(vp);
 1376         printf("\n");
 1377         return (0);
 1378 }
 1379 
 1380 /*
 1381  * Close wrapper for fifos.
 1382  *
 1383  * Update the times on the inode then do device close.
 1384  */
 1385 static int
 1386 ext2fifo_close(struct vop_close_args *ap)
 1387 {
 1388         struct vnode *vp = ap->a_vp;
 1389 
 1390         VI_LOCK(vp);
 1391         if (vp->v_usecount > 1)
 1392                 ext2_itimes_locked(vp);
 1393         VI_UNLOCK(vp);
 1394         return (fifo_specops.vop_close(ap));
 1395 }
 1396 
 1397 /*
 1398  * Kqfilter wrapper for fifos.
 1399  *
 1400  * Fall through to ext2 kqfilter routines if needed 
 1401  */
 1402 static int
 1403 ext2fifo_kqfilter(struct vop_kqfilter_args *ap)
 1404 {
 1405         int error;
 1406 
 1407         error = fifo_specops.vop_kqfilter(ap);
 1408         if (error)
 1409                 error = vfs_kqfilter(ap);
 1410         return (error);
 1411 }
 1412 
 1413 /*
 1414  * Return POSIX pathconf information applicable to ext2 filesystems.
 1415  */
 1416 static int
 1417 ext2_pathconf(struct vop_pathconf_args *ap)
 1418 {
 1419 
 1420         switch (ap->a_name) {
 1421         case _PC_LINK_MAX:
 1422                 *ap->a_retval = EXT2_LINK_MAX;
 1423                 return (0);
 1424         case _PC_NAME_MAX:
 1425                 *ap->a_retval = NAME_MAX;
 1426                 return (0);
 1427         case _PC_PATH_MAX:
 1428                 *ap->a_retval = PATH_MAX;
 1429                 return (0);
 1430         case _PC_PIPE_BUF:
 1431                 *ap->a_retval = PIPE_BUF;
 1432                 return (0);
 1433         case _PC_CHOWN_RESTRICTED:
 1434                 *ap->a_retval = 1;
 1435                 return (0);
 1436         case _PC_NO_TRUNC:
 1437                 *ap->a_retval = 1;
 1438                 return (0);
 1439         case _PC_MIN_HOLE_SIZE:
 1440                 *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
 1441                 return(0);
 1442         default:
 1443                 return (EINVAL);
 1444         }
 1445         /* NOTREACHED */
 1446 }
 1447 
 1448 /*
 1449  * Vnode pointer to File handle
 1450  */
 1451 /* ARGSUSED */
 1452 static int
 1453 ext2_vptofh(struct vop_vptofh_args *ap)
 1454 {
 1455         struct inode *ip;
 1456         struct ufid *ufhp;
 1457 
 1458         ip = VTOI(ap->a_vp);
 1459         ufhp = (struct ufid *)ap->a_fhp;
 1460         ufhp->ufid_len = sizeof(struct ufid);
 1461         ufhp->ufid_ino = ip->i_number;
 1462         ufhp->ufid_gen = ip->i_gen;
 1463         return (0);
 1464 }
 1465 
 1466 /*
 1467  * Initialize the vnode associated with a new inode, handle aliased
 1468  * vnodes.
 1469  */
 1470 int
 1471 ext2_vinit(struct mount *mntp, struct vop_vector *fifoops, struct vnode **vpp)
 1472 {
 1473         struct inode *ip;
 1474         struct vnode *vp;
 1475 
 1476         vp = *vpp;
 1477         ip = VTOI(vp);
 1478         vp->v_type = IFTOVT(ip->i_mode);
 1479         if (vp->v_type == VFIFO)
 1480                 vp->v_op = fifoops;
 1481 
 1482         if (ip->i_number == EXT2_ROOTINO)
 1483                 vp->v_vflag |= VV_ROOT;
 1484         ip->i_modrev = init_va_filerev();
 1485         *vpp = vp;
 1486         return (0);
 1487 }
 1488 
 1489 /*
 1490  * Allocate a new inode.
 1491  */
 1492 static int
 1493 ext2_makeinode(int mode, struct vnode *dvp, struct vnode **vpp,
 1494     struct componentname *cnp)
 1495 {
 1496         struct inode *ip, *pdir;
 1497         struct vnode *tvp;
 1498         int error;
 1499 
 1500         pdir = VTOI(dvp);
 1501 #ifdef INVARIANTS
 1502         if ((cnp->cn_flags & HASBUF) == 0)
 1503                 panic("ext2_makeinode: no name");
 1504 #endif
 1505         *vpp = NULL;
 1506         if ((mode & IFMT) == 0)
 1507                 mode |= IFREG;
 1508 
 1509         error = ext2_valloc(dvp, mode, cnp->cn_cred, &tvp);
 1510         if (error) {
 1511                 return (error);
 1512         }
 1513         ip = VTOI(tvp);
 1514         ip->i_gid = pdir->i_gid;
 1515 #ifdef SUIDDIR
 1516         {
 1517                 /*
 1518                  * if we are
 1519                  * not the owner of the directory,
 1520                  * and we are hacking owners here, (only do this where told to)
 1521                  * and we are not giving it TOO root, (would subvert quotas)
 1522                  * then go ahead and give it to the other user.
 1523                  * Note that this drops off the execute bits for security.
 1524                  */
 1525                 if ( (dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
 1526                      (pdir->i_mode & ISUID) &&
 1527                      (pdir->i_uid != cnp->cn_cred->cr_uid) && pdir->i_uid) {
 1528                         ip->i_uid = pdir->i_uid;
 1529                         mode &= ~07111;
 1530                 } else {
 1531                         ip->i_uid = cnp->cn_cred->cr_uid;
 1532                 }
 1533         }
 1534 #else
 1535         ip->i_uid = cnp->cn_cred->cr_uid;
 1536 #endif
 1537         ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
 1538         ip->i_mode = mode;
 1539         tvp->v_type = IFTOVT(mode);     /* Rest init'd in getnewvnode(). */
 1540         ip->i_nlink = 1;
 1541         if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred)) {
 1542                 if (priv_check_cred(cnp->cn_cred, PRIV_VFS_RETAINSUGID, 0))
 1543                         ip->i_mode &= ~ISGID;
 1544         }
 1545 
 1546         if (cnp->cn_flags & ISWHITEOUT)
 1547                 ip->i_flags |= UF_OPAQUE;
 1548 
 1549         /*
 1550          * Make sure inode goes to disk before directory entry.
 1551          */
 1552         error = ext2_update(tvp, !DOINGASYNC(tvp));
 1553         if (error)
 1554                 goto bad;
 1555         error = ext2_direnter(ip, dvp, cnp);
 1556         if (error)
 1557                 goto bad;
 1558 
 1559         *vpp = tvp;
 1560         return (0);
 1561 
 1562 bad:
 1563         /*
 1564          * Write error occurred trying to update the inode
 1565          * or the directory so must deallocate the inode.
 1566          */
 1567         ip->i_nlink = 0;
 1568         ip->i_flag |= IN_CHANGE;
 1569         vput(tvp);
 1570         return (error);
 1571 }
 1572 
 1573 /*
 1574  * Vnode op for reading.
 1575  */
 1576 static int
 1577 ext2_read(struct vop_read_args *ap)
 1578 {
 1579         struct vnode *vp;
 1580         struct inode *ip;
 1581         struct uio *uio;
 1582         struct m_ext2fs *fs;
 1583         struct buf *bp;
 1584         daddr_t lbn, nextlbn;
 1585         off_t bytesinfile;
 1586         long size, xfersize, blkoffset;
 1587         int error, orig_resid, seqcount;
 1588         int ioflag;
 1589 
 1590         vp = ap->a_vp;
 1591         uio = ap->a_uio;
 1592         ioflag = ap->a_ioflag;
 1593 
 1594         seqcount = ap->a_ioflag >> IO_SEQSHIFT;
 1595         ip = VTOI(vp);
 1596 
 1597 #ifdef INVARIANTS
 1598         if (uio->uio_rw != UIO_READ)
 1599                 panic("%s: mode", "ext2_read");
 1600 
 1601         if (vp->v_type == VLNK) {
 1602                 if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
 1603                         panic("%s: short symlink", "ext2_read");
 1604         } else if (vp->v_type != VREG && vp->v_type != VDIR)
 1605                 panic("%s: type %d", "ext2_read", vp->v_type);
 1606 #endif
 1607         orig_resid = uio->uio_resid;
 1608         KASSERT(orig_resid >= 0, ("ext2_read: uio->uio_resid < 0"));
 1609         if (orig_resid == 0)
 1610                 return (0);
 1611         KASSERT(uio->uio_offset >= 0, ("ext2_read: uio->uio_offset < 0"));
 1612         fs = ip->i_e2fs;
 1613         if (uio->uio_offset < ip->i_size &&
 1614             uio->uio_offset >= fs->e2fs_maxfilesize)
 1615                 return (EOVERFLOW);
 1616 
 1617         for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
 1618                 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
 1619                         break;
 1620                 lbn = lblkno(fs, uio->uio_offset);
 1621                 nextlbn = lbn + 1;
 1622                 size = blksize(fs, ip, lbn);
 1623                 blkoffset = blkoff(fs, uio->uio_offset);
 1624 
 1625                 xfersize = fs->e2fs_fsize - blkoffset;
 1626                 if (uio->uio_resid < xfersize)
 1627                         xfersize = uio->uio_resid;
 1628                 if (bytesinfile < xfersize)
 1629                         xfersize = bytesinfile;
 1630 
 1631                 if (lblktosize(fs, nextlbn) >= ip->i_size)
 1632                         error = bread(vp, lbn, size, NOCRED, &bp);
 1633                 else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0)
 1634                         error = cluster_read(vp, ip->i_size, lbn, size,
 1635                             NOCRED, blkoffset + uio->uio_resid, seqcount, &bp);
 1636                 else if (seqcount > 1) {
 1637                         int nextsize = blksize(fs, ip, nextlbn);
 1638                         error = breadn(vp, lbn,
 1639                             size, &nextlbn, &nextsize, 1, NOCRED, &bp);
 1640                 } else
 1641                         error = bread(vp, lbn, size, NOCRED, &bp);
 1642                 if (error) {
 1643                         brelse(bp);
 1644                         bp = NULL;
 1645                         break;
 1646                 }
 1647 
 1648                 /*
 1649                  * If IO_DIRECT then set B_DIRECT for the buffer.  This
 1650                  * will cause us to attempt to release the buffer later on
 1651                  * and will cause the buffer cache to attempt to free the
 1652                  * underlying pages.
 1653                  */
 1654                 if (ioflag & IO_DIRECT)
 1655                         bp->b_flags |= B_DIRECT;
 1656 
 1657                 /*
 1658                  * We should only get non-zero b_resid when an I/O error
 1659                  * has occurred, which should cause us to break above.
 1660                  * However, if the short read did not cause an error,
 1661                  * then we want to ensure that we do not uiomove bad
 1662                  * or uninitialized data.
 1663                  */
 1664                 size -= bp->b_resid;
 1665                 if (size < xfersize) {
 1666                         if (size == 0)
 1667                                 break;
 1668                         xfersize = size;
 1669                 }
 1670                 error = uiomove((char *)bp->b_data + blkoffset,
 1671                         (int)xfersize, uio);
 1672                 if (error)
 1673                         break;
 1674 
 1675                 if (ioflag & (IO_VMIO|IO_DIRECT)) {
 1676                         /*
 1677                          * If it's VMIO or direct I/O, then we don't
 1678                          * need the buf, mark it available for
 1679                          * freeing. If it's non-direct VMIO, the VM has
 1680                          * the data.
 1681                          */
 1682                         bp->b_flags |= B_RELBUF;
 1683                         brelse(bp);
 1684                 } else {
 1685                         /*
 1686                          * Otherwise let whoever
 1687                          * made the request take care of
 1688                          * freeing it. We just queue
 1689                          * it onto another list.
 1690                          */
 1691                         bqrelse(bp);
 1692                 }
 1693         }
 1694 
 1695         /* 
 1696          * This can only happen in the case of an error
 1697          * because the loop above resets bp to NULL on each iteration
 1698          * and on normal completion has not set a new value into it.
 1699          * so it must have come from a 'break' statement
 1700          */
 1701         if (bp != NULL) {
 1702                 if (ioflag & (IO_VMIO|IO_DIRECT)) {
 1703                         bp->b_flags |= B_RELBUF;
 1704                         brelse(bp);
 1705                 } else {
 1706                         bqrelse(bp);
 1707                 }
 1708         }
 1709 
 1710         if ((error == 0 || uio->uio_resid != orig_resid) &&
 1711             (vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
 1712                 ip->i_flag |= IN_ACCESS;
 1713         return (error);
 1714 }
 1715 
 1716 static int
 1717 ext2_ioctl(struct vop_ioctl_args *ap)
 1718 {
 1719 
 1720         switch (ap->a_command) {
 1721         case FIOSEEKDATA:
 1722         case FIOSEEKHOLE:
 1723                 return (vn_bmap_seekhole(ap->a_vp, ap->a_command,
 1724                     (off_t *)ap->a_data, ap->a_cred));
 1725         default:
 1726                 return (ENOTTY);
 1727         }
 1728 }
 1729 
 1730 /*
 1731  * Vnode op for writing.
 1732  */
 1733 static int
 1734 ext2_write(struct vop_write_args *ap)
 1735 {
 1736         struct vnode *vp;
 1737         struct uio *uio;
 1738         struct inode *ip;
 1739         struct m_ext2fs *fs;
 1740         struct buf *bp;
 1741         daddr_t lbn;
 1742         off_t osize;
 1743         int blkoffset, error, flags, ioflag, resid, size, seqcount, xfersize;
 1744 
 1745         ioflag = ap->a_ioflag;
 1746         uio = ap->a_uio;
 1747         vp = ap->a_vp;
 1748 
 1749         seqcount = ioflag >> IO_SEQSHIFT;
 1750         ip = VTOI(vp);
 1751 
 1752 #ifdef INVARIANTS
 1753         if (uio->uio_rw != UIO_WRITE)
 1754                 panic("%s: mode", "ext2_write");
 1755 #endif
 1756 
 1757         switch (vp->v_type) {
 1758         case VREG:
 1759                 if (ioflag & IO_APPEND)
 1760                         uio->uio_offset = ip->i_size;
 1761                 if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
 1762                         return (EPERM);
 1763                 /* FALLTHROUGH */
 1764         case VLNK:
 1765                 break;
 1766         case VDIR:
 1767                 /* XXX differs from ffs -- this is called from ext2_mkdir(). */
 1768                 if ((ioflag & IO_SYNC) == 0)
 1769                 panic("ext2_write: nonsync dir write");
 1770                 break;
 1771         default:
 1772                 panic("ext2_write: type %p %d (%jd,%jd)", (void *)vp,
 1773                     vp->v_type, (intmax_t)uio->uio_offset,
 1774                     (intmax_t)uio->uio_resid);
 1775         }
 1776 
 1777         KASSERT(uio->uio_resid >= 0, ("ext2_write: uio->uio_resid < 0"));
 1778         KASSERT(uio->uio_offset >= 0, ("ext2_write: uio->uio_offset < 0"));
 1779         fs = ip->i_e2fs;
 1780         if ((uoff_t)uio->uio_offset + uio->uio_resid > fs->e2fs_maxfilesize)
 1781                 return (EFBIG);
 1782         /*
 1783          * Maybe this should be above the vnode op call, but so long as
 1784          * file servers have no limits, I don't think it matters.
 1785          */
 1786         if (vn_rlimit_fsize(vp, uio, uio->uio_td))
 1787                 return (EFBIG);
 1788 
 1789         resid = uio->uio_resid;
 1790         osize = ip->i_size;
 1791         if (seqcount > BA_SEQMAX)
 1792                 flags = BA_SEQMAX << BA_SEQSHIFT;
 1793         else
 1794                 flags = seqcount << BA_SEQSHIFT;
 1795         if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
 1796                 flags |= IO_SYNC;
 1797 
 1798         for (error = 0; uio->uio_resid > 0;) {
 1799                 lbn = lblkno(fs, uio->uio_offset);
 1800                 blkoffset = blkoff(fs, uio->uio_offset);
 1801                 xfersize = fs->e2fs_fsize - blkoffset;
 1802                 if (uio->uio_resid < xfersize)
 1803                         xfersize = uio->uio_resid;
 1804                 if (uio->uio_offset + xfersize > ip->i_size)
 1805                         vnode_pager_setsize(vp, uio->uio_offset + xfersize);
 1806 
 1807                 /*
 1808                  * We must perform a read-before-write if the transfer size
 1809                  * does not cover the entire buffer.
 1810                  */
 1811                 if (fs->e2fs_bsize > xfersize)
 1812                         flags |= BA_CLRBUF;
 1813                 else
 1814                         flags &= ~BA_CLRBUF;
 1815                 error = ext2_balloc(ip, lbn, blkoffset + xfersize,
 1816                     ap->a_cred, &bp, flags);
 1817                 if (error != 0)
 1818                         break;
 1819 
 1820                 if ((ioflag & (IO_SYNC|IO_INVAL)) == (IO_SYNC|IO_INVAL))
 1821                         bp->b_flags |= B_NOCACHE;
 1822                 if (uio->uio_offset + xfersize > ip->i_size)
 1823                         ip->i_size = uio->uio_offset + xfersize;
 1824                 size = blksize(fs, ip, lbn) - bp->b_resid;
 1825                 if (size < xfersize)
 1826                         xfersize = size;
 1827 
 1828                 error =
 1829                     uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
 1830                 /*
 1831                  * If the buffer is not already filled and we encounter an
 1832                  * error while trying to fill it, we have to clear out any
 1833                  * garbage data from the pages instantiated for the buffer.
 1834                  * If we do not, a failed uiomove() during a write can leave
 1835                  * the prior contents of the pages exposed to a userland mmap.
 1836                  *
 1837                  * Note that we need only clear buffers with a transfer size
 1838                  * equal to the block size because buffers with a shorter
 1839                  * transfer size were cleared above by the call to ext2_balloc()
 1840                  * with the BA_CLRBUF flag set.
 1841                  *
 1842                  * If the source region for uiomove identically mmaps the
 1843                  * buffer, uiomove() performed the NOP copy, and the buffer
 1844                  * content remains valid because the page fault handler
 1845                  * validated the pages.
 1846                  */
 1847                 if (error != 0 && (bp->b_flags & B_CACHE) == 0 &&
 1848                     fs->e2fs_bsize == xfersize)
 1849                         vfs_bio_clrbuf(bp);
 1850                 if (ioflag & (IO_VMIO|IO_DIRECT)) {
 1851                         bp->b_flags |= B_RELBUF;
 1852                 }
 1853 
 1854                 /*
 1855                  * If IO_SYNC each buffer is written synchronously.  Otherwise
 1856                  * if we have a severe page deficiency write the buffer
 1857                  * asynchronously.  Otherwise try to cluster, and if that
 1858                  * doesn't do it then either do an async write (if O_DIRECT),
 1859                  * or a delayed write (if not).
 1860                  */
 1861                 if (ioflag & IO_SYNC) {
 1862                         (void)bwrite(bp);
 1863                 } else if (vm_page_count_severe() ||
 1864                     buf_dirty_count_severe() ||
 1865                     (ioflag & IO_ASYNC)) {
 1866                         bp->b_flags |= B_CLUSTEROK;
 1867                         bawrite(bp);
 1868                 } else if (xfersize + blkoffset == fs->e2fs_fsize) {
 1869                         if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
 1870                                 bp->b_flags |= B_CLUSTEROK;
 1871                                 cluster_write(vp, bp, ip->i_size, seqcount);
 1872                         } else {
 1873                                 bawrite(bp);
 1874                         }
 1875                 } else if (ioflag & IO_DIRECT) {
 1876                         bp->b_flags |= B_CLUSTEROK;
 1877                         bawrite(bp);
 1878                 } else {
 1879                         bp->b_flags |= B_CLUSTEROK;
 1880                         bdwrite(bp);
 1881                 }
 1882                 if (error || xfersize == 0)
 1883                         break;
 1884         }
 1885         /*
 1886          * If we successfully wrote any data, and we are not the superuser
 1887          * we clear the setuid and setgid bits as a precaution against
 1888          * tampering.
 1889          */
 1890         if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid &&
 1891             ap->a_cred) {
 1892                 if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID, 0))
 1893                         ip->i_mode &= ~(ISUID | ISGID);
 1894         }
 1895         if (error) {
 1896                 if (ioflag & IO_UNIT) {
 1897                         (void)ext2_truncate(vp, osize,
 1898                             ioflag & IO_SYNC, ap->a_cred, uio->uio_td);
 1899                         uio->uio_offset -= resid - uio->uio_resid;
 1900                         uio->uio_resid = resid;
 1901                 }
 1902         }
 1903         if (uio->uio_resid != resid) {
 1904                ip->i_flag |= IN_CHANGE | IN_UPDATE;
 1905                if (ioflag & IO_SYNC)
 1906                        error = ext2_update(vp, 1);
 1907        }
 1908         return (error);
 1909 }

Cache object: 74985797dcabedd327dd7cd65b8d2f12


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