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/10.0/sys/fs/ext2fs/ext2_vnops.c 254283 2013-08-13 15:40:43Z 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 <ufs/ufs/dir.h>
   76 
   77 #include <fs/ext2fs/fs.h>
   78 #include <fs/ext2fs/inode.h>
   79 #include <fs/ext2fs/ext2_extern.h>
   80 #include <fs/ext2fs/ext2fs.h>
   81 #include <fs/ext2fs/ext2_dinode.h>
   82 #include <fs/ext2fs/ext2_dir.h>
   83 #include <fs/ext2fs/ext2_mount.h>
   84 
   85 static int ext2_makeinode(int mode, struct vnode *, struct vnode **, struct componentname *);
   86 static void ext2_itimes_locked(struct vnode *);
   87 static int ext4_ext_read(struct vop_read_args *);
   88 static int ext2_ind_read(struct vop_read_args *);
   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 & (SF_IMMUTABLE | SF_APPEND)) {
  399                                 error = securelevel_gt(cred, 0);
  400                                 if (error)
  401                                         return (error);
  402                         }
  403                 } else {
  404                         if (ip->i_flags & (SF_IMMUTABLE | SF_APPEND) ||
  405                             ((vap->va_flags ^ ip->i_flags) & SF_SETTABLE))
  406                                 return (EPERM);
  407                 }
  408                 ip->i_flags = vap->va_flags;
  409                 ip->i_flag |= IN_CHANGE;
  410                 if (ip->i_flags & (IMMUTABLE | APPEND))
  411                         return (0);
  412         }
  413         if (ip->i_flags & (IMMUTABLE | APPEND))
  414                 return (EPERM);
  415         /*
  416          * Go through the fields and update iff not VNOVAL.
  417          */
  418         if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
  419                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  420                         return (EROFS);
  421                 if ((error = ext2_chown(vp, vap->va_uid, vap->va_gid, cred,
  422                     td)) != 0)
  423                         return (error);
  424         }
  425         if (vap->va_size != VNOVAL) {
  426                 /*
  427                  * Disallow write attempts on read-only file systems;
  428                  * unless the file is a socket, fifo, or a block or
  429                  * character device resident on the file system.
  430                  */
  431                 switch (vp->v_type) {
  432                 case VDIR:
  433                         return (EISDIR);
  434                 case VLNK:
  435                 case VREG:
  436                         if (vp->v_mount->mnt_flag & MNT_RDONLY)
  437                                 return (EROFS);
  438                         break;
  439                 default:
  440                         break;
  441                 }
  442                 if ((error = ext2_truncate(vp, vap->va_size, 0, cred, td)) != 0)
  443                         return (error);
  444         }
  445         if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
  446                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  447                         return (EROFS);
  448                 /*
  449                  * From utimes(2):
  450                  * If times is NULL, ... The caller must be the owner of
  451                  * the file, have permission to write the file, or be the
  452                  * super-user.
  453                  * If times is non-NULL, ... The caller must be the owner of
  454                  * the file or be the super-user.
  455                  */
  456                 if ((error = VOP_ACCESS(vp, VADMIN, cred, td)) &&
  457                     ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
  458                     (error = VOP_ACCESS(vp, VWRITE, cred, td))))
  459                         return (error);
  460                 if (vap->va_atime.tv_sec != VNOVAL)
  461                         ip->i_flag |= IN_ACCESS;
  462                 if (vap->va_mtime.tv_sec != VNOVAL)
  463                         ip->i_flag |= IN_CHANGE | IN_UPDATE;
  464                 ext2_itimes(vp);
  465                 if (vap->va_atime.tv_sec != VNOVAL) {
  466                         ip->i_atime = vap->va_atime.tv_sec;
  467                         ip->i_atimensec = vap->va_atime.tv_nsec;
  468                 }
  469                 if (vap->va_mtime.tv_sec != VNOVAL) {
  470                         ip->i_mtime = vap->va_mtime.tv_sec;
  471                         ip->i_mtimensec = vap->va_mtime.tv_nsec;
  472                 }
  473                 ip->i_birthtime = vap->va_birthtime.tv_sec;
  474                 ip->i_birthnsec = vap->va_birthtime.tv_nsec;
  475                 error = ext2_update(vp, 0);
  476                 if (error)
  477                         return (error);
  478         }
  479         error = 0;
  480         if (vap->va_mode != (mode_t)VNOVAL) {
  481                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  482                         return (EROFS);
  483                 error = ext2_chmod(vp, (int)vap->va_mode, cred, td);
  484         }
  485         return (error);
  486 }
  487 
  488 /*
  489  * Change the mode on a file.
  490  * Inode must be locked before calling.
  491  */
  492 static int
  493 ext2_chmod(struct vnode *vp, int mode, struct ucred *cred, struct thread *td)
  494 {
  495         struct inode *ip = VTOI(vp);
  496         int error;
  497 
  498         /*
  499          * To modify the permissions on a file, must possess VADMIN
  500          * for that file.
  501          */
  502         if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
  503                 return (error);
  504         /*
  505          * Privileged processes may set the sticky bit on non-directories,
  506          * as well as set the setgid bit on a file with a group that the
  507          * process is not a member of.
  508          */
  509         if (vp->v_type != VDIR && (mode & S_ISTXT)) {
  510                 error = priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0);
  511                 if (error)
  512                         return (EFTYPE);
  513         }
  514         if (!groupmember(ip->i_gid, cred) && (mode & ISGID)) {
  515                 error = priv_check_cred(cred, PRIV_VFS_SETGID, 0);
  516                 if (error)
  517                         return (error);
  518         }
  519         ip->i_mode &= ~ALLPERMS;
  520         ip->i_mode |= (mode & ALLPERMS);
  521         ip->i_flag |= IN_CHANGE;
  522         return (0);
  523 }
  524 
  525 /*
  526  * Perform chown operation on inode ip;
  527  * inode must be locked prior to call.
  528  */
  529 static int
  530 ext2_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
  531     struct thread *td)
  532 {
  533         struct inode *ip = VTOI(vp);
  534         uid_t ouid;
  535         gid_t ogid;
  536         int error = 0;
  537 
  538         if (uid == (uid_t)VNOVAL)
  539                 uid = ip->i_uid;
  540         if (gid == (gid_t)VNOVAL)
  541                 gid = ip->i_gid;
  542         /*
  543          * To modify the ownership of a file, must possess VADMIN
  544          * for that file.
  545          */
  546         if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
  547                 return (error);
  548         /*
  549          * To change the owner of a file, or change the group of a file
  550          * to a group of which we are not a member, the caller must
  551          * have privilege.
  552          */
  553         if (uid != ip->i_uid || (gid != ip->i_gid &&
  554             !groupmember(gid, cred))) {
  555                 error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0);
  556                 if (error)
  557                         return (error);
  558         }
  559         ogid = ip->i_gid;
  560         ouid = ip->i_uid;
  561         ip->i_gid = gid;
  562         ip->i_uid = uid;
  563         ip->i_flag |= IN_CHANGE;
  564         if ((ip->i_mode & (ISUID | ISGID)) && (ouid != uid || ogid != gid)) {
  565                 if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0) != 0)
  566                         ip->i_mode &= ~(ISUID | ISGID);
  567         }
  568         return (0);
  569 }
  570 
  571 /*
  572  * Synch an open file.
  573  */
  574 /* ARGSUSED */
  575 static int
  576 ext2_fsync(struct vop_fsync_args *ap)
  577 {
  578         /*
  579          * Flush all dirty buffers associated with a vnode.
  580          */
  581 
  582         vop_stdfsync(ap);
  583 
  584         return (ext2_update(ap->a_vp, ap->a_waitfor == MNT_WAIT));
  585 }
  586 
  587 /*
  588  * Mknod vnode call
  589  */
  590 /* ARGSUSED */
  591 static int
  592 ext2_mknod(struct vop_mknod_args *ap)
  593 {
  594         struct vattr *vap = ap->a_vap;
  595         struct vnode **vpp = ap->a_vpp;
  596         struct inode *ip;
  597         ino_t ino;
  598         int error;
  599 
  600         error = ext2_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
  601             ap->a_dvp, vpp, ap->a_cnp);
  602         if (error)
  603                 return (error);
  604         ip = VTOI(*vpp);
  605         ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
  606         if (vap->va_rdev != VNOVAL) {
  607                 /*
  608                  * Want to be able to use this to make badblock
  609                  * inodes, so don't truncate the dev number.
  610                  */
  611                 ip->i_rdev = vap->va_rdev;
  612         }
  613         /*
  614          * Remove inode, then reload it through VFS_VGET so it is
  615          * checked to see if it is an alias of an existing entry in
  616          * the inode cache.      XXX I don't believe this is necessary now.
  617          */
  618         (*vpp)->v_type = VNON;
  619         ino = ip->i_number;     /* Save this before vgone() invalidates ip. */
  620         vgone(*vpp);
  621         vput(*vpp);
  622         error = VFS_VGET(ap->a_dvp->v_mount, ino, LK_EXCLUSIVE, vpp);
  623         if (error) {
  624                 *vpp = NULL;
  625                 return (error);
  626         }
  627         return (0);
  628 }
  629 
  630 static int
  631 ext2_remove(struct vop_remove_args *ap)
  632 {
  633         struct inode *ip;
  634         struct vnode *vp = ap->a_vp;
  635         struct vnode *dvp = ap->a_dvp;
  636         int error;
  637 
  638         ip = VTOI(vp);
  639         if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
  640             (VTOI(dvp)->i_flags & APPEND)) {
  641                 error = EPERM;
  642                 goto out;
  643         }
  644         error = ext2_dirremove(dvp, ap->a_cnp);
  645         if (error == 0) {
  646                 ip->i_nlink--;
  647                 ip->i_flag |= IN_CHANGE;
  648         }
  649 out:
  650         return (error);
  651 }
  652 
  653 /*
  654  * link vnode call
  655  */
  656 static int
  657 ext2_link(struct vop_link_args *ap)
  658 {
  659         struct vnode *vp = ap->a_vp;
  660         struct vnode *tdvp = ap->a_tdvp;
  661         struct componentname *cnp = ap->a_cnp;
  662         struct inode *ip;
  663         int error;
  664 
  665 #ifdef INVARIANTS
  666         if ((cnp->cn_flags & HASBUF) == 0)
  667                 panic("ext2_link: no name");
  668 #endif
  669         if (tdvp->v_mount != vp->v_mount) {
  670                 error = EXDEV;
  671                 goto out;
  672         }
  673         ip = VTOI(vp);
  674         if ((nlink_t)ip->i_nlink >= EXT2_LINK_MAX) {
  675                 error = EMLINK;
  676                 goto out;
  677         }
  678         if (ip->i_flags & (IMMUTABLE | APPEND)) {
  679                 error = EPERM;
  680                 goto out;
  681         }
  682         ip->i_nlink++;
  683         ip->i_flag |= IN_CHANGE;
  684         error = ext2_update(vp, !DOINGASYNC(vp));
  685         if (!error)
  686                 error = ext2_direnter(ip, tdvp, cnp);
  687         if (error) {
  688                 ip->i_nlink--;
  689                 ip->i_flag |= IN_CHANGE;
  690         }
  691 out:
  692         return (error);
  693 }
  694 
  695 /*
  696  * Rename system call.
  697  *      rename("foo", "bar");
  698  * is essentially
  699  *      unlink("bar");
  700  *      link("foo", "bar");
  701  *      unlink("foo");
  702  * but ``atomically''.  Can't do full commit without saving state in the
  703  * inode on disk which isn't feasible at this time.  Best we can do is
  704  * always guarantee the target exists.
  705  *
  706  * Basic algorithm is:
  707  *
  708  * 1) Bump link count on source while we're linking it to the
  709  *    target.  This also ensure the inode won't be deleted out
  710  *    from underneath us while we work (it may be truncated by
  711  *    a concurrent `trunc' or `open' for creation).
  712  * 2) Link source to destination.  If destination already exists,
  713  *    delete it first.
  714  * 3) Unlink source reference to inode if still around. If a
  715  *    directory was moved and the parent of the destination
  716  *    is different from the source, patch the ".." entry in the
  717  *    directory.
  718  */
  719 static int
  720 ext2_rename(struct vop_rename_args *ap)
  721 {
  722         struct vnode *tvp = ap->a_tvp;
  723         struct vnode *tdvp = ap->a_tdvp;
  724         struct vnode *fvp = ap->a_fvp;
  725         struct vnode *fdvp = ap->a_fdvp;
  726         struct componentname *tcnp = ap->a_tcnp;
  727         struct componentname *fcnp = ap->a_fcnp;
  728         struct inode *ip, *xp, *dp;
  729         struct dirtemplate dirbuf;
  730         int doingdirectory = 0, oldparent = 0, newparent = 0;
  731         int error = 0;
  732         u_char namlen;
  733 
  734 #ifdef INVARIANTS
  735         if ((tcnp->cn_flags & HASBUF) == 0 ||
  736             (fcnp->cn_flags & HASBUF) == 0)
  737                 panic("ext2_rename: no name");
  738 #endif
  739         /*
  740          * Check for cross-device rename.
  741          */
  742         if ((fvp->v_mount != tdvp->v_mount) ||
  743             (tvp && (fvp->v_mount != tvp->v_mount))) {
  744                 error = EXDEV;
  745 abortit:
  746                 if (tdvp == tvp)
  747                         vrele(tdvp);
  748                 else
  749                         vput(tdvp);
  750                 if (tvp)
  751                         vput(tvp);
  752                 vrele(fdvp);
  753                 vrele(fvp);
  754                 return (error);
  755         }
  756 
  757         if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
  758             (VTOI(tdvp)->i_flags & APPEND))) {
  759                 error = EPERM;
  760                 goto abortit;
  761         }
  762 
  763         /*
  764          * Renaming a file to itself has no effect.  The upper layers should
  765          * not call us in that case.  Temporarily just warn if they do.
  766          */
  767         if (fvp == tvp) {
  768                 printf("ext2_rename: fvp == tvp (can't happen)\n");
  769                 error = 0;
  770                 goto abortit;
  771         }
  772 
  773         if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
  774                 goto abortit;
  775         dp = VTOI(fdvp);
  776         ip = VTOI(fvp);
  777         if (ip->i_nlink >= EXT2_LINK_MAX) {
  778                 VOP_UNLOCK(fvp, 0);
  779                 error = EMLINK;
  780                 goto abortit;
  781         }
  782         if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
  783             || (dp->i_flags & APPEND)) {
  784                 VOP_UNLOCK(fvp, 0);
  785                 error = EPERM;
  786                 goto abortit;
  787         }
  788         if ((ip->i_mode & IFMT) == IFDIR) {
  789                 /*
  790                  * Avoid ".", "..", and aliases of "." for obvious reasons.
  791                  */
  792                 if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
  793                     dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & ISDOTDOT ||
  794                     (ip->i_flag & IN_RENAME)) {
  795                         VOP_UNLOCK(fvp, 0);
  796                         error = EINVAL;
  797                         goto abortit;
  798                 }
  799                 ip->i_flag |= IN_RENAME;
  800                 oldparent = dp->i_number;
  801                 doingdirectory++;
  802         }
  803         vrele(fdvp);
  804 
  805         /*
  806          * When the target exists, both the directory
  807          * and target vnodes are returned locked.
  808          */
  809         dp = VTOI(tdvp);
  810         xp = NULL;
  811         if (tvp)
  812                 xp = VTOI(tvp);
  813 
  814         /*
  815          * 1) Bump link count while we're moving stuff
  816          *    around.  If we crash somewhere before
  817          *    completing our work, the link count
  818          *    may be wrong, but correctable.
  819          */
  820         ip->i_nlink++;
  821         ip->i_flag |= IN_CHANGE;
  822         if ((error = ext2_update(fvp, !DOINGASYNC(fvp))) != 0) {
  823                 VOP_UNLOCK(fvp, 0);
  824                 goto bad;
  825         }
  826 
  827         /*
  828          * If ".." must be changed (ie the directory gets a new
  829          * parent) then the source directory must not be in the
  830          * directory hierarchy above the target, as this would
  831          * orphan everything below the source directory. Also
  832          * the user must have write permission in the source so
  833          * as to be able to change "..". We must repeat the call
  834          * to namei, as the parent directory is unlocked by the
  835          * call to checkpath().
  836          */
  837         error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_thread);
  838         VOP_UNLOCK(fvp, 0);
  839         if (oldparent != dp->i_number)
  840                 newparent = dp->i_number;
  841         if (doingdirectory && newparent) {
  842                 if (error)      /* write access check above */
  843                         goto bad;
  844                 if (xp != NULL)
  845                         vput(tvp);
  846                 error = ext2_checkpath(ip, dp, tcnp->cn_cred);
  847                 if (error)
  848                         goto out;
  849                 VREF(tdvp);
  850                 error = relookup(tdvp, &tvp, tcnp);
  851                 if (error)
  852                         goto out;
  853                 vrele(tdvp);
  854                 dp = VTOI(tdvp);
  855                 xp = NULL;
  856                 if (tvp)
  857                         xp = VTOI(tvp);
  858         }
  859         /*
  860          * 2) If target doesn't exist, link the target
  861          *    to the source and unlink the source.
  862          *    Otherwise, rewrite the target directory
  863          *    entry to reference the source inode and
  864          *    expunge the original entry's existence.
  865          */
  866         if (xp == NULL) {
  867                 if (dp->i_devvp != ip->i_devvp)
  868                         panic("ext2_rename: EXDEV");
  869                 /*
  870                  * Account for ".." in new directory.
  871                  * When source and destination have the same
  872                  * parent we don't fool with the link count.
  873                  */
  874                 if (doingdirectory && newparent) {
  875                         if ((nlink_t)dp->i_nlink >= EXT2_LINK_MAX) {
  876                                 error = EMLINK;
  877                                 goto bad;
  878                         }
  879                         dp->i_nlink++;
  880                         dp->i_flag |= IN_CHANGE;
  881                         error = ext2_update(tdvp, !DOINGASYNC(tdvp));
  882                         if (error)
  883                                 goto bad;
  884                 }
  885                 error = ext2_direnter(ip, tdvp, tcnp);
  886                 if (error) {
  887                         if (doingdirectory && newparent) {
  888                                 dp->i_nlink--;
  889                                 dp->i_flag |= IN_CHANGE;
  890                                 (void)ext2_update(tdvp, 1);
  891                         }
  892                         goto bad;
  893                 }
  894                 vput(tdvp);
  895         } else {
  896                 if (xp->i_devvp != dp->i_devvp || xp->i_devvp != ip->i_devvp)
  897                        panic("ext2_rename: EXDEV");
  898                 /*
  899                  * Short circuit rename(foo, foo).
  900                  */
  901                 if (xp->i_number == ip->i_number)
  902                         panic("ext2_rename: same file");
  903                 /*
  904                  * If the parent directory is "sticky", then the user must
  905                  * own the parent directory, or the destination of the rename,
  906                  * otherwise the destination may not be changed (except by
  907                  * root). This implements append-only directories.
  908                  */
  909                 if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
  910                     tcnp->cn_cred->cr_uid != dp->i_uid &&
  911                     xp->i_uid != tcnp->cn_cred->cr_uid) {
  912                         error = EPERM;
  913                         goto bad;
  914                 }
  915                 /*
  916                  * Target must be empty if a directory and have no links
  917                  * to it. Also, ensure source and target are compatible
  918                  * (both directories, or both not directories).
  919                  */
  920                 if ((xp->i_mode&IFMT) == IFDIR) {
  921                         if (! ext2_dirempty(xp, dp->i_number, tcnp->cn_cred) || 
  922                             xp->i_nlink > 2) {
  923                                 error = ENOTEMPTY;
  924                                 goto bad;
  925                         }
  926                         if (!doingdirectory) {
  927                                 error = ENOTDIR;
  928                                 goto bad;
  929                         }
  930                         cache_purge(tdvp);
  931                 } else if (doingdirectory) {
  932                         error = EISDIR;
  933                         goto bad;
  934                 }
  935                 error = ext2_dirrewrite(dp, ip, tcnp);
  936                 if (error)
  937                         goto bad;
  938                 /*
  939                  * If the target directory is in the same
  940                  * directory as the source directory,
  941                  * decrement the link count on the parent
  942                  * of the target directory.
  943                  */
  944                 if (doingdirectory && !newparent) {
  945                        dp->i_nlink--;
  946                        dp->i_flag |= IN_CHANGE;
  947                 }
  948                 vput(tdvp);
  949                 /*
  950                  * Adjust the link count of the target to
  951                  * reflect the dirrewrite above.  If this is
  952                  * a directory it is empty and there are
  953                  * no links to it, so we can squash the inode and
  954                  * any space associated with it.  We disallowed
  955                  * renaming over top of a directory with links to
  956                  * it above, as the remaining link would point to
  957                  * a directory without "." or ".." entries.
  958                  */
  959                 xp->i_nlink--;
  960                 if (doingdirectory) {
  961                         if (--xp->i_nlink != 0)
  962                                 panic("ext2_rename: linked directory");
  963                         error = ext2_truncate(tvp, (off_t)0, IO_SYNC,
  964                             tcnp->cn_cred, tcnp->cn_thread);
  965                 }
  966                 xp->i_flag |= IN_CHANGE;
  967                 vput(tvp);
  968                 xp = NULL;
  969         }
  970 
  971         /*
  972          * 3) Unlink the source.
  973          */
  974         fcnp->cn_flags &= ~MODMASK;
  975         fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
  976         VREF(fdvp);
  977         error = relookup(fdvp, &fvp, fcnp);
  978         if (error == 0)
  979                 vrele(fdvp);
  980         if (fvp != NULL) {
  981                 xp = VTOI(fvp);
  982                 dp = VTOI(fdvp);
  983         } else {
  984                 /*
  985                  * From name has disappeared.
  986                  */
  987                 if (doingdirectory)
  988                         panic("ext2_rename: lost dir entry");
  989                 vrele(ap->a_fvp);
  990                 return (0);
  991         }
  992         /*
  993          * Ensure that the directory entry still exists and has not
  994          * changed while the new name has been entered. If the source is
  995          * a file then the entry may have been unlinked or renamed. In
  996          * either case there is no further work to be done. If the source
  997          * is a directory then it cannot have been rmdir'ed; its link
  998          * count of three would cause a rmdir to fail with ENOTEMPTY.
  999          * The IN_RENAME flag ensures that it cannot be moved by another
 1000          * rename.
 1001          */
 1002         if (xp != ip) {
 1003                 if (doingdirectory)
 1004                         panic("ext2_rename: lost dir entry");
 1005         } else {
 1006                 /*
 1007                  * If the source is a directory with a
 1008                  * new parent, the link count of the old
 1009                  * parent directory must be decremented
 1010                  * and ".." set to point to the new parent.
 1011                  */
 1012                 if (doingdirectory && newparent) {
 1013                         dp->i_nlink--;
 1014                         dp->i_flag |= IN_CHANGE;
 1015                         error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
 1016                                 sizeof(struct dirtemplate), (off_t)0,
 1017                                 UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
 1018                                 tcnp->cn_cred, NOCRED, NULL, NULL);
 1019                         if (error == 0) {
 1020                                 /* Like ufs little-endian: */
 1021                                 namlen = dirbuf.dotdot_type;
 1022                                 if (namlen != 2 ||
 1023                                     dirbuf.dotdot_name[0] != '.' ||
 1024                                     dirbuf.dotdot_name[1] != '.') {
 1025                                         ext2_dirbad(xp, (doff_t)12,
 1026                                             "rename: mangled dir");
 1027                                 } else {
 1028                                         dirbuf.dotdot_ino = newparent;
 1029                                         (void) vn_rdwr(UIO_WRITE, fvp,
 1030                                             (caddr_t)&dirbuf,
 1031                                             sizeof(struct dirtemplate),
 1032                                             (off_t)0, UIO_SYSSPACE,
 1033                                             IO_NODELOCKED | IO_SYNC |
 1034                                             IO_NOMACCHECK, tcnp->cn_cred,
 1035                                             NOCRED, NULL, NULL);
 1036                                         cache_purge(fdvp);
 1037                                 }
 1038                         }
 1039                 }
 1040                 error = ext2_dirremove(fdvp, fcnp);
 1041                 if (!error) {
 1042                         xp->i_nlink--;
 1043                         xp->i_flag |= IN_CHANGE;
 1044                 }
 1045                 xp->i_flag &= ~IN_RENAME;
 1046         }
 1047         if (dp)
 1048                 vput(fdvp);
 1049         if (xp)
 1050                 vput(fvp);
 1051         vrele(ap->a_fvp);
 1052         return (error);
 1053 
 1054 bad:
 1055         if (xp)
 1056                 vput(ITOV(xp));
 1057         vput(ITOV(dp));
 1058 out:
 1059         if (doingdirectory)
 1060                 ip->i_flag &= ~IN_RENAME;
 1061         if (vn_lock(fvp, LK_EXCLUSIVE) == 0) {
 1062                 ip->i_nlink--;
 1063                 ip->i_flag |= IN_CHANGE;
 1064                 ip->i_flag &= ~IN_RENAME;
 1065                 vput(fvp);
 1066         } else
 1067                 vrele(fvp);
 1068         return (error);
 1069 }
 1070 
 1071 /*
 1072  * Mkdir system call
 1073  */
 1074 static int
 1075 ext2_mkdir(struct vop_mkdir_args *ap)
 1076 {
 1077         struct vnode *dvp = ap->a_dvp;
 1078         struct vattr *vap = ap->a_vap;
 1079         struct componentname *cnp = ap->a_cnp;
 1080         struct inode *ip, *dp;
 1081         struct vnode *tvp;
 1082         struct dirtemplate dirtemplate, *dtp;
 1083         int error, dmode;
 1084 
 1085 #ifdef INVARIANTS
 1086         if ((cnp->cn_flags & HASBUF) == 0)
 1087                 panic("ext2_mkdir: no name");
 1088 #endif
 1089         dp = VTOI(dvp);
 1090         if ((nlink_t)dp->i_nlink >= EXT2_LINK_MAX) {
 1091                 error = EMLINK;
 1092                 goto out;
 1093         }
 1094         dmode = vap->va_mode & 0777;
 1095         dmode |= IFDIR;
 1096         /*
 1097          * Must simulate part of ext2_makeinode here to acquire the inode,
 1098          * but not have it entered in the parent directory. The entry is
 1099          * made later after writing "." and ".." entries.
 1100          */
 1101         error = ext2_valloc(dvp, dmode, cnp->cn_cred, &tvp);
 1102         if (error)
 1103                 goto out;
 1104         ip = VTOI(tvp);
 1105         ip->i_gid = dp->i_gid;
 1106 #ifdef SUIDDIR
 1107         {
 1108                 /*
 1109                  * if we are hacking owners here, (only do this where told to)
 1110                  * and we are not giving it TOO root, (would subvert quotas)
 1111                  * then go ahead and give it to the other user.
 1112                  * The new directory also inherits the SUID bit. 
 1113                  * If user's UID and dir UID are the same,
 1114                  * 'give it away' so that the SUID is still forced on.
 1115                  */
 1116                 if ( (dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
 1117                    (dp->i_mode & ISUID) && dp->i_uid) {
 1118                         dmode |= ISUID;
 1119                         ip->i_uid = dp->i_uid;
 1120                 } else {
 1121                         ip->i_uid = cnp->cn_cred->cr_uid;
 1122                 }
 1123         }
 1124 #else
 1125         ip->i_uid = cnp->cn_cred->cr_uid;
 1126 #endif
 1127         ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
 1128         ip->i_mode = dmode;
 1129         tvp->v_type = VDIR;     /* Rest init'd in getnewvnode(). */
 1130         ip->i_nlink = 2;
 1131         if (cnp->cn_flags & ISWHITEOUT)
 1132                 ip->i_flags |= UF_OPAQUE;
 1133         error = ext2_update(tvp, 1);
 1134 
 1135         /*
 1136          * Bump link count in parent directory
 1137          * to reflect work done below.  Should
 1138          * be done before reference is created
 1139          * so reparation is possible if we crash.
 1140          */
 1141         dp->i_nlink++;
 1142         dp->i_flag |= IN_CHANGE;
 1143         error = ext2_update(dvp, !DOINGASYNC(dvp));
 1144         if (error)
 1145                 goto bad;
 1146 
 1147         /* Initialize directory with "." and ".." from static template. */
 1148         if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs,
 1149             EXT2F_INCOMPAT_FTYPE))
 1150                 dtp = &mastertemplate;
 1151         else
 1152                 dtp = &omastertemplate;
 1153         dirtemplate = *dtp;
 1154         dirtemplate.dot_ino = ip->i_number;
 1155         dirtemplate.dotdot_ino = dp->i_number;
 1156         /* note that in ext2 DIRBLKSIZ == blocksize, not DEV_BSIZE 
 1157          * so let's just redefine it - for this function only
 1158          */
 1159 #undef  DIRBLKSIZ 
 1160 #define DIRBLKSIZ  VTOI(dvp)->i_e2fs->e2fs_bsize
 1161         dirtemplate.dotdot_reclen = DIRBLKSIZ - 12;
 1162         error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)&dirtemplate,
 1163             sizeof(dirtemplate), (off_t)0, UIO_SYSSPACE,
 1164             IO_NODELOCKED | IO_SYNC | IO_NOMACCHECK, cnp->cn_cred, NOCRED,
 1165             NULL, NULL);
 1166         if (error) {
 1167                 dp->i_nlink--;
 1168                 dp->i_flag |= IN_CHANGE;
 1169                 goto bad;
 1170         }
 1171         if (DIRBLKSIZ > VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
 1172                 /* XXX should grow with balloc() */
 1173                 panic("ext2_mkdir: blksize");
 1174         else {
 1175                 ip->i_size = DIRBLKSIZ;
 1176                 ip->i_flag |= IN_CHANGE;
 1177         }
 1178 
 1179         /* Directory set up, now install its entry in the parent directory. */
 1180         error = ext2_direnter(ip, dvp, cnp);
 1181         if (error) {
 1182                 dp->i_nlink--;
 1183                 dp->i_flag |= IN_CHANGE;
 1184         }
 1185 bad:
 1186         /*
 1187          * No need to do an explicit VOP_TRUNCATE here, vrele will do this
 1188          * for us because we set the link count to 0.
 1189          */
 1190         if (error) {
 1191                 ip->i_nlink = 0;
 1192                 ip->i_flag |= IN_CHANGE;
 1193                 vput(tvp);
 1194         } else
 1195                 *ap->a_vpp = tvp;
 1196 out:
 1197         return (error);
 1198 #undef  DIRBLKSIZ
 1199 #define DIRBLKSIZ  DEV_BSIZE
 1200 }
 1201 
 1202 /*
 1203  * Rmdir system call.
 1204  */
 1205 static int
 1206 ext2_rmdir(struct vop_rmdir_args *ap)
 1207 {
 1208         struct vnode *vp = ap->a_vp;
 1209         struct vnode *dvp = ap->a_dvp;
 1210         struct componentname *cnp = ap->a_cnp;
 1211         struct inode *ip, *dp;
 1212         int error;
 1213 
 1214         ip = VTOI(vp);
 1215         dp = VTOI(dvp);
 1216 
 1217         /*
 1218          * Verify the directory is empty (and valid).
 1219          * (Rmdir ".." won't be valid since
 1220          *  ".." will contain a reference to
 1221          *  the current directory and thus be
 1222          *  non-empty.)
 1223          */
 1224         error = 0;
 1225         if (ip->i_nlink != 2 || !ext2_dirempty(ip, dp->i_number, cnp->cn_cred)) {
 1226                 error = ENOTEMPTY;
 1227                 goto out;
 1228         }
 1229         if ((dp->i_flags & APPEND)
 1230             || (ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
 1231                 error = EPERM;
 1232                 goto out;
 1233         }
 1234         /*
 1235          * Delete reference to directory before purging
 1236          * inode.  If we crash in between, the directory
 1237          * will be reattached to lost+found,
 1238          */
 1239         error = ext2_dirremove(dvp, cnp);
 1240         if (error)
 1241                 goto out;
 1242         dp->i_nlink--;
 1243         dp->i_flag |= IN_CHANGE;
 1244         cache_purge(dvp);
 1245         VOP_UNLOCK(dvp, 0);
 1246         /*
 1247          * Truncate inode.  The only stuff left
 1248          * in the directory is "." and "..".  The
 1249          * "." reference is inconsequential since
 1250          * we're quashing it.  The ".." reference
 1251          * has already been adjusted above.  We've
 1252          * removed the "." reference and the reference
 1253          * in the parent directory, but there may be
 1254          * other hard links so decrement by 2 and
 1255          * worry about them later.
 1256          */
 1257         ip->i_nlink -= 2;
 1258         error = ext2_truncate(vp, (off_t)0, IO_SYNC, cnp->cn_cred,
 1259             cnp->cn_thread);
 1260         cache_purge(ITOV(ip));
 1261         if (vn_lock(dvp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
 1262                 VOP_UNLOCK(vp, 0);
 1263                 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
 1264                 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 1265         }
 1266 out:
 1267         return (error);
 1268 }
 1269 
 1270 /*
 1271  * symlink -- make a symbolic link
 1272  */
 1273 static int
 1274 ext2_symlink(struct vop_symlink_args *ap)
 1275 {
 1276         struct vnode *vp, **vpp = ap->a_vpp;
 1277         struct inode *ip;
 1278         int len, error;
 1279 
 1280         error = ext2_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
 1281             vpp, ap->a_cnp);
 1282         if (error)
 1283                 return (error);
 1284         vp = *vpp;
 1285         len = strlen(ap->a_target);
 1286         if (len < vp->v_mount->mnt_maxsymlinklen) {
 1287                 ip = VTOI(vp);
 1288                 bcopy(ap->a_target, (char *)ip->i_shortlink, len);
 1289                 ip->i_size = len;
 1290                 ip->i_flag |= IN_CHANGE | IN_UPDATE;
 1291         } else
 1292                 error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
 1293                     UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
 1294                     ap->a_cnp->cn_cred, NOCRED, NULL, NULL);
 1295         if (error)
 1296                 vput(vp);
 1297         return (error);
 1298 }
 1299 
 1300 /*
 1301  * Return target name of a symbolic link
 1302  */
 1303 static int
 1304 ext2_readlink(struct vop_readlink_args *ap)
 1305 {
 1306         struct vnode *vp = ap->a_vp;
 1307         struct inode *ip = VTOI(vp);
 1308         int isize;
 1309 
 1310         isize = ip->i_size;
 1311         if (isize < vp->v_mount->mnt_maxsymlinklen) {
 1312                 uiomove((char *)ip->i_shortlink, isize, ap->a_uio);
 1313                 return (0);
 1314         }
 1315         return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
 1316 }
 1317 
 1318 /*
 1319  * Calculate the logical to physical mapping if not done already,
 1320  * then call the device strategy routine.
 1321  *
 1322  * In order to be able to swap to a file, the ext2_bmaparray() operation may not
 1323  * deadlock on memory.  See ext2_bmap() for details.
 1324  */
 1325 static int
 1326 ext2_strategy(struct vop_strategy_args *ap)
 1327 {
 1328         struct buf *bp = ap->a_bp;
 1329         struct vnode *vp = ap->a_vp;
 1330         struct inode *ip;
 1331         struct bufobj *bo;
 1332         daddr_t blkno;
 1333         int error;
 1334 
 1335         ip = VTOI(vp);
 1336         if (vp->v_type == VBLK || vp->v_type == VCHR)
 1337                 panic("ext2_strategy: spec");
 1338         if (bp->b_blkno == bp->b_lblkno) {
 1339                 error = ext2_bmaparray(vp, bp->b_lblkno, &blkno, NULL, NULL);
 1340                 bp->b_blkno = blkno;
 1341                 if (error) {
 1342                         bp->b_error = error;
 1343                         bp->b_ioflags |= BIO_ERROR;
 1344                         bufdone(bp);
 1345                         return (0);
 1346                 }
 1347                 if ((long)bp->b_blkno == -1)
 1348                         vfs_bio_clrbuf(bp);
 1349         }
 1350         if ((long)bp->b_blkno == -1) {
 1351                 bufdone(bp);
 1352                 return (0);
 1353         }
 1354         bp->b_iooffset = dbtob(bp->b_blkno);
 1355         bo = VFSTOEXT2(vp->v_mount)->um_bo;
 1356         BO_STRATEGY(bo, bp);
 1357         return (0);
 1358 }
 1359 
 1360 /*
 1361  * Print out the contents of an inode.
 1362  */
 1363 static int
 1364 ext2_print(struct vop_print_args *ap)
 1365 {
 1366         struct vnode *vp = ap->a_vp;
 1367         struct inode *ip = VTOI(vp);
 1368 
 1369         vn_printf(ip->i_devvp, "\tino %lu", (u_long)ip->i_number);
 1370         if (vp->v_type == VFIFO)
 1371                 fifo_printinfo(vp);
 1372         printf("\n");
 1373         return (0);
 1374 }
 1375 
 1376 /*
 1377  * Close wrapper for fifos.
 1378  *
 1379  * Update the times on the inode then do device close.
 1380  */
 1381 static int
 1382 ext2fifo_close(struct vop_close_args *ap)
 1383 {
 1384         struct vnode *vp = ap->a_vp;
 1385 
 1386         VI_LOCK(vp);
 1387         if (vp->v_usecount > 1)
 1388                 ext2_itimes_locked(vp);
 1389         VI_UNLOCK(vp);
 1390         return (fifo_specops.vop_close(ap));
 1391 }
 1392 
 1393 /*
 1394  * Kqfilter wrapper for fifos.
 1395  *
 1396  * Fall through to ext2 kqfilter routines if needed 
 1397  */
 1398 static int
 1399 ext2fifo_kqfilter(struct vop_kqfilter_args *ap)
 1400 {
 1401         int error;
 1402 
 1403         error = fifo_specops.vop_kqfilter(ap);
 1404         if (error)
 1405                 error = vfs_kqfilter(ap);
 1406         return (error);
 1407 }
 1408 
 1409 /*
 1410  * Return POSIX pathconf information applicable to ext2 filesystems.
 1411  */
 1412 static int
 1413 ext2_pathconf(struct vop_pathconf_args *ap)
 1414 {
 1415         int error = 0;
 1416 
 1417         switch (ap->a_name) {
 1418         case _PC_LINK_MAX:
 1419                 *ap->a_retval = EXT2_LINK_MAX;
 1420                 break;
 1421         case _PC_NAME_MAX:
 1422                 *ap->a_retval = NAME_MAX;
 1423                 break;
 1424         case _PC_PATH_MAX:
 1425                 *ap->a_retval = PATH_MAX;
 1426                 break;
 1427         case _PC_PIPE_BUF:
 1428                 *ap->a_retval = PIPE_BUF;
 1429                 break;
 1430         case _PC_CHOWN_RESTRICTED:
 1431                 *ap->a_retval = 1;
 1432                 break;
 1433         case _PC_NO_TRUNC:
 1434                 *ap->a_retval = 1;
 1435                 break;
 1436         case _PC_MIN_HOLE_SIZE:
 1437                 *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
 1438                 break;
 1439         case _PC_ASYNC_IO:
 1440                 /* _PC_ASYNC_IO should have been handled by upper layers. */
 1441                 KASSERT(0, ("_PC_ASYNC_IO should not get here"));
 1442                 error = EINVAL;
 1443                 break;
 1444         case _PC_PRIO_IO:
 1445                 *ap->a_retval = 0;
 1446                 break;
 1447         case _PC_SYNC_IO:
 1448                 *ap->a_retval = 0;
 1449                 break;
 1450         case _PC_ALLOC_SIZE_MIN:
 1451                 *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_bsize;
 1452                 break;
 1453         case _PC_FILESIZEBITS:
 1454                 *ap->a_retval = 64;
 1455                 break;
 1456         case _PC_REC_INCR_XFER_SIZE:
 1457                 *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
 1458                 break;
 1459         case _PC_REC_MAX_XFER_SIZE:
 1460                 *ap->a_retval = -1; /* means ``unlimited'' */
 1461                 break;
 1462         case _PC_REC_MIN_XFER_SIZE:
 1463                 *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
 1464                 break;
 1465         case _PC_REC_XFER_ALIGN:
 1466                 *ap->a_retval = PAGE_SIZE;
 1467                 break;
 1468         case _PC_SYMLINK_MAX:
 1469                 *ap->a_retval = MAXPATHLEN;
 1470                 break;
 1471 
 1472         default:
 1473                 error = EINVAL;
 1474                 break;
 1475         }
 1476         return (error);
 1477 }
 1478 
 1479 /*
 1480  * Vnode pointer to File handle
 1481  */
 1482 /* ARGSUSED */
 1483 static int
 1484 ext2_vptofh(struct vop_vptofh_args *ap)
 1485 {
 1486         struct inode *ip;
 1487         struct ufid *ufhp;
 1488 
 1489         ip = VTOI(ap->a_vp);
 1490         ufhp = (struct ufid *)ap->a_fhp;
 1491         ufhp->ufid_len = sizeof(struct ufid);
 1492         ufhp->ufid_ino = ip->i_number;
 1493         ufhp->ufid_gen = ip->i_gen;
 1494         return (0);
 1495 }
 1496 
 1497 /*
 1498  * Initialize the vnode associated with a new inode, handle aliased
 1499  * vnodes.
 1500  */
 1501 int
 1502 ext2_vinit(struct mount *mntp, struct vop_vector *fifoops, struct vnode **vpp)
 1503 {
 1504         struct inode *ip;
 1505         struct vnode *vp;
 1506 
 1507         vp = *vpp;
 1508         ip = VTOI(vp);
 1509         vp->v_type = IFTOVT(ip->i_mode);
 1510         if (vp->v_type == VFIFO)
 1511                 vp->v_op = fifoops;
 1512 
 1513         if (ip->i_number == EXT2_ROOTINO)
 1514                 vp->v_vflag |= VV_ROOT;
 1515         ip->i_modrev = init_va_filerev();
 1516         *vpp = vp;
 1517         return (0);
 1518 }
 1519 
 1520 /*
 1521  * Allocate a new inode.
 1522  */
 1523 static int
 1524 ext2_makeinode(int mode, struct vnode *dvp, struct vnode **vpp,
 1525     struct componentname *cnp)
 1526 {
 1527         struct inode *ip, *pdir;
 1528         struct vnode *tvp;
 1529         int error;
 1530 
 1531         pdir = VTOI(dvp);
 1532 #ifdef INVARIANTS
 1533         if ((cnp->cn_flags & HASBUF) == 0)
 1534                 panic("ext2_makeinode: no name");
 1535 #endif
 1536         *vpp = NULL;
 1537         if ((mode & IFMT) == 0)
 1538                 mode |= IFREG;
 1539 
 1540         error = ext2_valloc(dvp, mode, cnp->cn_cred, &tvp);
 1541         if (error) {
 1542                 return (error);
 1543         }
 1544         ip = VTOI(tvp);
 1545         ip->i_gid = pdir->i_gid;
 1546 #ifdef SUIDDIR
 1547         {
 1548                 /*
 1549                  * if we are
 1550                  * not the owner of the directory,
 1551                  * and we are hacking owners here, (only do this where told to)
 1552                  * and we are not giving it TOO root, (would subvert quotas)
 1553                  * then go ahead and give it to the other user.
 1554                  * Note that this drops off the execute bits for security.
 1555                  */
 1556                 if ( (dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
 1557                      (pdir->i_mode & ISUID) &&
 1558                      (pdir->i_uid != cnp->cn_cred->cr_uid) && pdir->i_uid) {
 1559                         ip->i_uid = pdir->i_uid;
 1560                         mode &= ~07111;
 1561                 } else {
 1562                         ip->i_uid = cnp->cn_cred->cr_uid;
 1563                 }
 1564         }
 1565 #else
 1566         ip->i_uid = cnp->cn_cred->cr_uid;
 1567 #endif
 1568         ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
 1569         ip->i_mode = mode;
 1570         tvp->v_type = IFTOVT(mode);     /* Rest init'd in getnewvnode(). */
 1571         ip->i_nlink = 1;
 1572         if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred)) {
 1573                 if (priv_check_cred(cnp->cn_cred, PRIV_VFS_RETAINSUGID, 0))
 1574                         ip->i_mode &= ~ISGID;
 1575         }
 1576 
 1577         if (cnp->cn_flags & ISWHITEOUT)
 1578                 ip->i_flags |= UF_OPAQUE;
 1579 
 1580         /*
 1581          * Make sure inode goes to disk before directory entry.
 1582          */
 1583         error = ext2_update(tvp, !DOINGASYNC(tvp));
 1584         if (error)
 1585                 goto bad;
 1586         error = ext2_direnter(ip, dvp, cnp);
 1587         if (error)
 1588                 goto bad;
 1589 
 1590         *vpp = tvp;
 1591         return (0);
 1592 
 1593 bad:
 1594         /*
 1595          * Write error occurred trying to update the inode
 1596          * or the directory so must deallocate the inode.
 1597          */
 1598         ip->i_nlink = 0;
 1599         ip->i_flag |= IN_CHANGE;
 1600         vput(tvp);
 1601         return (error);
 1602 }
 1603 
 1604 /*
 1605  * Vnode op for reading.
 1606  */
 1607 static int
 1608 ext2_read(struct vop_read_args *ap)
 1609 {
 1610         struct vnode *vp;
 1611         struct inode *ip;
 1612         int error;
 1613 
 1614         vp = ap->a_vp;
 1615         ip = VTOI(vp);
 1616 
 1617         /*EXT4_EXT_LOCK(ip);*/
 1618         if (ip->i_flags & EXT4_EXTENTS)
 1619                 error = ext4_ext_read(ap);
 1620         else
 1621                 error = ext2_ind_read(ap);
 1622         /*EXT4_EXT_UNLOCK(ip);*/
 1623         return (error);
 1624 }
 1625 
 1626 
 1627 /*
 1628  * Vnode op for reading.
 1629  */
 1630 static int
 1631 ext2_ind_read(struct vop_read_args *ap)
 1632 {
 1633         struct vnode *vp;
 1634         struct inode *ip;
 1635         struct uio *uio;
 1636         struct m_ext2fs *fs;
 1637         struct buf *bp;
 1638         daddr_t lbn, nextlbn;
 1639         off_t bytesinfile;
 1640         long size, xfersize, blkoffset;
 1641         int error, orig_resid, seqcount;
 1642         int ioflag;
 1643 
 1644         vp = ap->a_vp;
 1645         uio = ap->a_uio;
 1646         ioflag = ap->a_ioflag;
 1647 
 1648         seqcount = ap->a_ioflag >> IO_SEQSHIFT;
 1649         ip = VTOI(vp);
 1650 
 1651 #ifdef INVARIANTS
 1652         if (uio->uio_rw != UIO_READ)
 1653                 panic("%s: mode", "ext2_read");
 1654 
 1655         if (vp->v_type == VLNK) {
 1656                 if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
 1657                         panic("%s: short symlink", "ext2_read");
 1658         } else if (vp->v_type != VREG && vp->v_type != VDIR)
 1659                 panic("%s: type %d", "ext2_read", vp->v_type);
 1660 #endif
 1661         orig_resid = uio->uio_resid;
 1662         KASSERT(orig_resid >= 0, ("ext2_read: uio->uio_resid < 0"));
 1663         if (orig_resid == 0)
 1664                 return (0);
 1665         KASSERT(uio->uio_offset >= 0, ("ext2_read: uio->uio_offset < 0"));
 1666         fs = ip->i_e2fs;
 1667         if (uio->uio_offset < ip->i_size &&
 1668             uio->uio_offset >= fs->e2fs_maxfilesize)
 1669                 return (EOVERFLOW);
 1670 
 1671         for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
 1672                 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
 1673                         break;
 1674                 lbn = lblkno(fs, uio->uio_offset);
 1675                 nextlbn = lbn + 1;
 1676                 size = blksize(fs, ip, lbn);
 1677                 blkoffset = blkoff(fs, uio->uio_offset);
 1678 
 1679                 xfersize = fs->e2fs_fsize - blkoffset;
 1680                 if (uio->uio_resid < xfersize)
 1681                         xfersize = uio->uio_resid;
 1682                 if (bytesinfile < xfersize)
 1683                         xfersize = bytesinfile;
 1684 
 1685                 if (lblktosize(fs, nextlbn) >= ip->i_size)
 1686                         error = bread(vp, lbn, size, NOCRED, &bp);
 1687                 else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
 1688                         error = cluster_read(vp, ip->i_size, lbn, size,
 1689                             NOCRED, blkoffset + uio->uio_resid, seqcount,
 1690                             0, &bp);
 1691                 } else if (seqcount > 1) {
 1692                         int nextsize = blksize(fs, ip, nextlbn);
 1693                         error = breadn(vp, lbn,
 1694                             size, &nextlbn, &nextsize, 1, NOCRED, &bp);
 1695                 } else
 1696                         error = bread(vp, lbn, size, NOCRED, &bp);
 1697                 if (error) {
 1698                         brelse(bp);
 1699                         bp = NULL;
 1700                         break;
 1701                 }
 1702 
 1703                 /*
 1704                  * If IO_DIRECT then set B_DIRECT for the buffer.  This
 1705                  * will cause us to attempt to release the buffer later on
 1706                  * and will cause the buffer cache to attempt to free the
 1707                  * underlying pages.
 1708                  */
 1709                 if (ioflag & IO_DIRECT)
 1710                         bp->b_flags |= B_DIRECT;
 1711 
 1712                 /*
 1713                  * We should only get non-zero b_resid when an I/O error
 1714                  * has occurred, which should cause us to break above.
 1715                  * However, if the short read did not cause an error,
 1716                  * then we want to ensure that we do not uiomove bad
 1717                  * or uninitialized data.
 1718                  */
 1719                 size -= bp->b_resid;
 1720                 if (size < xfersize) {
 1721                         if (size == 0)
 1722                                 break;
 1723                         xfersize = size;
 1724                 }
 1725                 error = uiomove((char *)bp->b_data + blkoffset,
 1726                         (int)xfersize, uio);
 1727                 if (error)
 1728                         break;
 1729 
 1730                 if (ioflag & (IO_VMIO|IO_DIRECT)) {
 1731                         /*
 1732                          * If it's VMIO or direct I/O, then we don't
 1733                          * need the buf, mark it available for
 1734                          * freeing. If it's non-direct VMIO, the VM has
 1735                          * the data.
 1736                          */
 1737                         bp->b_flags |= B_RELBUF;
 1738                         brelse(bp);
 1739                 } else {
 1740                         /*
 1741                          * Otherwise let whoever
 1742                          * made the request take care of
 1743                          * freeing it. We just queue
 1744                          * it onto another list.
 1745                          */
 1746                         bqrelse(bp);
 1747                 }
 1748         }
 1749 
 1750         /* 
 1751          * This can only happen in the case of an error
 1752          * because the loop above resets bp to NULL on each iteration
 1753          * and on normal completion has not set a new value into it.
 1754          * so it must have come from a 'break' statement
 1755          */
 1756         if (bp != NULL) {
 1757                 if (ioflag & (IO_VMIO|IO_DIRECT)) {
 1758                         bp->b_flags |= B_RELBUF;
 1759                         brelse(bp);
 1760                 } else {
 1761                         bqrelse(bp);
 1762                 }
 1763         }
 1764 
 1765         if ((error == 0 || uio->uio_resid != orig_resid) &&
 1766             (vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
 1767                 ip->i_flag |= IN_ACCESS;
 1768         return (error);
 1769 }
 1770 
 1771 static int
 1772 ext2_ioctl(struct vop_ioctl_args *ap)
 1773 {
 1774 
 1775         switch (ap->a_command) {
 1776         case FIOSEEKDATA:
 1777         case FIOSEEKHOLE:
 1778                 return (vn_bmap_seekhole(ap->a_vp, ap->a_command,
 1779                     (off_t *)ap->a_data, ap->a_cred));
 1780         default:
 1781                 return (ENOTTY);
 1782         }
 1783 }
 1784 
 1785 /*
 1786  * this function handles ext4 extents block mapping
 1787  */
 1788 static int
 1789 ext4_ext_read(struct vop_read_args *ap)
 1790 {
 1791         struct vnode *vp;
 1792         struct inode *ip;
 1793         struct uio *uio;
 1794         struct m_ext2fs *fs;
 1795         struct buf *bp;
 1796         struct ext4_extent nex, *ep;
 1797         struct ext4_extent_path path;
 1798         daddr_t lbn, newblk;
 1799         off_t bytesinfile;
 1800         int cache_type;
 1801         ssize_t orig_resid;
 1802         int error;
 1803         long size, xfersize, blkoffset;
 1804 
 1805         vp = ap->a_vp;
 1806         ip = VTOI(vp);
 1807         uio = ap->a_uio;
 1808         memset(&path, 0, sizeof(path));
 1809 
 1810         orig_resid = uio->uio_resid;
 1811         KASSERT(orig_resid >= 0, ("%s: uio->uio_resid < 0", __func__));
 1812         if (orig_resid == 0)
 1813                 return (0);
 1814         KASSERT(uio->uio_offset >= 0, ("%s: uio->uio_offset < 0", __func__));
 1815         fs = ip->i_e2fs;
 1816         if (uio->uio_offset < ip->i_size && uio->uio_offset >= fs->e2fs_maxfilesize)
 1817                 return (EOVERFLOW);
 1818 
 1819         while (uio->uio_resid > 0) {
 1820                 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
 1821                         break;
 1822                 lbn = lblkno(fs, uio->uio_offset);
 1823                 size = blksize(fs, ip, lbn);
 1824                 blkoffset = blkoff(fs, uio->uio_offset);
 1825 
 1826                 xfersize = fs->e2fs_fsize - blkoffset;
 1827                 xfersize = MIN(xfersize, uio->uio_resid);
 1828                 xfersize = MIN(xfersize, bytesinfile);
 1829 
 1830                 /* get block from ext4 extent cache */
 1831                 cache_type = ext4_ext_in_cache(ip, lbn, &nex);
 1832                 switch (cache_type) {
 1833                 case EXT4_EXT_CACHE_NO:
 1834                         ext4_ext_find_extent(fs, ip, lbn, &path);
 1835                         ep = path.ep_ext;
 1836                         if (ep == NULL)
 1837                                 return (EIO);
 1838 
 1839                         ext4_ext_put_cache(ip, ep, EXT4_EXT_CACHE_IN);
 1840 
 1841                         newblk = lbn - ep->e_blk + (ep->e_start_lo |
 1842                             (daddr_t)ep->e_start_hi << 32);
 1843 
 1844                         if (path.ep_bp != NULL) {
 1845                                 brelse(path.ep_bp);
 1846                                 path.ep_bp = NULL;
 1847                         }
 1848                         break;
 1849 
 1850                 case EXT4_EXT_CACHE_GAP:
 1851                         /* block has not been allocated yet */
 1852                         return (0);
 1853 
 1854                 case EXT4_EXT_CACHE_IN:
 1855                         newblk = lbn - nex.e_blk + (nex.e_start_lo |
 1856                             (daddr_t)nex.e_start_hi << 32);
 1857                         break;
 1858 
 1859                 default:
 1860                         panic("%s: invalid cache type", __func__);
 1861                 }
 1862 
 1863                 error = bread(ip->i_devvp, fsbtodb(fs, newblk), size, NOCRED, &bp);
 1864                 if (error) {
 1865                         brelse(bp);
 1866                         return (error);
 1867                 }
 1868 
 1869                 size -= bp->b_resid;
 1870                 if (size < xfersize) {
 1871                         if (size == 0) {
 1872                                 bqrelse(bp);
 1873                                 break;
 1874                         }
 1875                         xfersize = size;
 1876                 }
 1877                 error = uiomove(bp->b_data + blkoffset, (int)xfersize, uio);
 1878                 bqrelse(bp);
 1879                 if (error)
 1880                         return (error);
 1881         }
 1882 
 1883         return (0);
 1884 }
 1885 
 1886 /*
 1887  * Vnode op for writing.
 1888  */
 1889 static int
 1890 ext2_write(struct vop_write_args *ap)
 1891 {
 1892         struct vnode *vp;
 1893         struct uio *uio;
 1894         struct inode *ip;
 1895         struct m_ext2fs *fs;
 1896         struct buf *bp;
 1897         daddr_t lbn;
 1898         off_t osize;
 1899         int blkoffset, error, flags, ioflag, resid, size, seqcount, xfersize;
 1900 
 1901         ioflag = ap->a_ioflag;
 1902         uio = ap->a_uio;
 1903         vp = ap->a_vp;
 1904 
 1905         seqcount = ioflag >> IO_SEQSHIFT;
 1906         ip = VTOI(vp);
 1907 
 1908 #ifdef INVARIANTS
 1909         if (uio->uio_rw != UIO_WRITE)
 1910                 panic("%s: mode", "ext2_write");
 1911 #endif
 1912 
 1913         switch (vp->v_type) {
 1914         case VREG:
 1915                 if (ioflag & IO_APPEND)
 1916                         uio->uio_offset = ip->i_size;
 1917                 if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
 1918                         return (EPERM);
 1919                 /* FALLTHROUGH */
 1920         case VLNK:
 1921                 break;
 1922         case VDIR:
 1923                 /* XXX differs from ffs -- this is called from ext2_mkdir(). */
 1924                 if ((ioflag & IO_SYNC) == 0)
 1925                 panic("ext2_write: nonsync dir write");
 1926                 break;
 1927         default:
 1928                 panic("ext2_write: type %p %d (%jd,%jd)", (void *)vp,
 1929                     vp->v_type, (intmax_t)uio->uio_offset,
 1930                     (intmax_t)uio->uio_resid);
 1931         }
 1932 
 1933         KASSERT(uio->uio_resid >= 0, ("ext2_write: uio->uio_resid < 0"));
 1934         KASSERT(uio->uio_offset >= 0, ("ext2_write: uio->uio_offset < 0"));
 1935         fs = ip->i_e2fs;
 1936         if ((uoff_t)uio->uio_offset + uio->uio_resid > fs->e2fs_maxfilesize)
 1937                 return (EFBIG);
 1938         /*
 1939          * Maybe this should be above the vnode op call, but so long as
 1940          * file servers have no limits, I don't think it matters.
 1941          */
 1942         if (vn_rlimit_fsize(vp, uio, uio->uio_td))
 1943                 return (EFBIG);
 1944 
 1945         resid = uio->uio_resid;
 1946         osize = ip->i_size;
 1947         if (seqcount > BA_SEQMAX)
 1948                 flags = BA_SEQMAX << BA_SEQSHIFT;
 1949         else
 1950                 flags = seqcount << BA_SEQSHIFT;
 1951         if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
 1952                 flags |= IO_SYNC;
 1953 
 1954         for (error = 0; uio->uio_resid > 0;) {
 1955                 lbn = lblkno(fs, uio->uio_offset);
 1956                 blkoffset = blkoff(fs, uio->uio_offset);
 1957                 xfersize = fs->e2fs_fsize - blkoffset;
 1958                 if (uio->uio_resid < xfersize)
 1959                         xfersize = uio->uio_resid;
 1960                 if (uio->uio_offset + xfersize > ip->i_size)
 1961                         vnode_pager_setsize(vp, uio->uio_offset + xfersize);
 1962 
 1963                 /*
 1964                  * We must perform a read-before-write if the transfer size
 1965                  * does not cover the entire buffer.
 1966                  */
 1967                 if (fs->e2fs_bsize > xfersize)
 1968                         flags |= BA_CLRBUF;
 1969                 else
 1970                         flags &= ~BA_CLRBUF;
 1971                 error = ext2_balloc(ip, lbn, blkoffset + xfersize,
 1972                     ap->a_cred, &bp, flags);
 1973                 if (error != 0)
 1974                         break;
 1975 
 1976                 if ((ioflag & (IO_SYNC|IO_INVAL)) == (IO_SYNC|IO_INVAL))
 1977                         bp->b_flags |= B_NOCACHE;
 1978                 if (uio->uio_offset + xfersize > ip->i_size)
 1979                         ip->i_size = uio->uio_offset + xfersize;
 1980                 size = blksize(fs, ip, lbn) - bp->b_resid;
 1981                 if (size < xfersize)
 1982                         xfersize = size;
 1983 
 1984                 error =
 1985                     uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
 1986                 /*
 1987                  * If the buffer is not already filled and we encounter an
 1988                  * error while trying to fill it, we have to clear out any
 1989                  * garbage data from the pages instantiated for the buffer.
 1990                  * If we do not, a failed uiomove() during a write can leave
 1991                  * the prior contents of the pages exposed to a userland mmap.
 1992                  *
 1993                  * Note that we need only clear buffers with a transfer size
 1994                  * equal to the block size because buffers with a shorter
 1995                  * transfer size were cleared above by the call to ext2_balloc()
 1996                  * with the BA_CLRBUF flag set.
 1997                  *
 1998                  * If the source region for uiomove identically mmaps the
 1999                  * buffer, uiomove() performed the NOP copy, and the buffer
 2000                  * content remains valid because the page fault handler
 2001                  * validated the pages.
 2002                  */
 2003                 if (error != 0 && (bp->b_flags & B_CACHE) == 0 &&
 2004                     fs->e2fs_bsize == xfersize)
 2005                         vfs_bio_clrbuf(bp);
 2006                 if (ioflag & (IO_VMIO|IO_DIRECT)) {
 2007                         bp->b_flags |= B_RELBUF;
 2008                 }
 2009 
 2010                 /*
 2011                  * If IO_SYNC each buffer is written synchronously.  Otherwise
 2012                  * if we have a severe page deficiency write the buffer
 2013                  * asynchronously.  Otherwise try to cluster, and if that
 2014                  * doesn't do it then either do an async write (if O_DIRECT),
 2015                  * or a delayed write (if not).
 2016                  */
 2017                 if (ioflag & IO_SYNC) {
 2018                         (void)bwrite(bp);
 2019                 } else if (vm_page_count_severe() ||
 2020                     buf_dirty_count_severe() ||
 2021                     (ioflag & IO_ASYNC)) {
 2022                         bp->b_flags |= B_CLUSTEROK;
 2023                         bawrite(bp);
 2024                 } else if (xfersize + blkoffset == fs->e2fs_fsize) {
 2025                         if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
 2026                                 bp->b_flags |= B_CLUSTEROK;
 2027                                 cluster_write(vp, bp, ip->i_size, seqcount, 0);
 2028                         } else {
 2029                                 bawrite(bp);
 2030                         }
 2031                 } else if (ioflag & IO_DIRECT) {
 2032                         bp->b_flags |= B_CLUSTEROK;
 2033                         bawrite(bp);
 2034                 } else {
 2035                         bp->b_flags |= B_CLUSTEROK;
 2036                         bdwrite(bp);
 2037                 }
 2038                 if (error || xfersize == 0)
 2039                         break;
 2040         }
 2041         /*
 2042          * If we successfully wrote any data, and we are not the superuser
 2043          * we clear the setuid and setgid bits as a precaution against
 2044          * tampering.
 2045          */
 2046         if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid &&
 2047             ap->a_cred) {
 2048                 if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID, 0))
 2049                         ip->i_mode &= ~(ISUID | ISGID);
 2050         }
 2051         if (error) {
 2052                 if (ioflag & IO_UNIT) {
 2053                         (void)ext2_truncate(vp, osize,
 2054                             ioflag & IO_SYNC, ap->a_cred, uio->uio_td);
 2055                         uio->uio_offset -= resid - uio->uio_resid;
 2056                         uio->uio_resid = resid;
 2057                 }
 2058         }
 2059         if (uio->uio_resid != resid) {
 2060                ip->i_flag |= IN_CHANGE | IN_UPDATE;
 2061                if (ioflag & IO_SYNC)
 2062                        error = ext2_update(vp, 1);
 2063        }
 2064         return (error);
 2065 }

Cache object: 2423c3b19e8fe0a49ab4bfdd228f60bb


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