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/10.4/sys/fs/ext2fs/ext2_vnops.c 317532 2017-04-27 23:14:01Z 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/rwlock.h>
   58 #include <sys/mount.h>
   59 #include <sys/unistd.h>
   60 #include <sys/time.h>
   61 #include <sys/vnode.h>
   62 #include <sys/namei.h>
   63 #include <sys/lockf.h>
   64 #include <sys/event.h>
   65 #include <sys/conf.h>
   66 #include <sys/file.h>
   67 
   68 #include <vm/vm.h>
   69 #include <vm/vm_param.h>
   70 #include <vm/vm_extern.h>
   71 #include <vm/vm_object.h>
   72 #include <vm/vm_page.h>
   73 #include <vm/vm_pager.h>
   74 #include <vm/vnode_pager.h>
   75 
   76 #include "opt_directio.h"
   77 
   78 #include <ufs/ufs/dir.h>
   79 
   80 #include <fs/ext2fs/fs.h>
   81 #include <fs/ext2fs/inode.h>
   82 #include <fs/ext2fs/ext2_extern.h>
   83 #include <fs/ext2fs/ext2fs.h>
   84 #include <fs/ext2fs/ext2_dinode.h>
   85 #include <fs/ext2fs/ext2_dir.h>
   86 #include <fs/ext2fs/ext2_mount.h>
   87 
   88 static int ext2_makeinode(int mode, struct vnode *, struct vnode **, struct componentname *);
   89 static void ext2_itimes_locked(struct vnode *);
   90 static int ext4_ext_read(struct vop_read_args *);
   91 static int ext2_ind_read(struct vop_read_args *);
   92 
   93 static vop_access_t     ext2_access;
   94 static int ext2_chmod(struct vnode *, int, struct ucred *, struct thread *);
   95 static int ext2_chown(struct vnode *, uid_t, gid_t, struct ucred *,
   96     struct thread *);
   97 static vop_close_t      ext2_close;
   98 static vop_create_t     ext2_create;
   99 static vop_fsync_t      ext2_fsync;
  100 static vop_getpages_t   ext2_getpages;
  101 static vop_getattr_t    ext2_getattr;
  102 static vop_ioctl_t      ext2_ioctl;
  103 static vop_link_t       ext2_link;
  104 static vop_mkdir_t      ext2_mkdir;
  105 static vop_mknod_t      ext2_mknod;
  106 static vop_open_t       ext2_open;
  107 static vop_pathconf_t   ext2_pathconf;
  108 static vop_print_t      ext2_print;
  109 static vop_read_t       ext2_read;
  110 static vop_readlink_t   ext2_readlink;
  111 static vop_remove_t     ext2_remove;
  112 static vop_rename_t     ext2_rename;
  113 static vop_rmdir_t      ext2_rmdir;
  114 static vop_setattr_t    ext2_setattr;
  115 static vop_strategy_t   ext2_strategy;
  116 static vop_symlink_t    ext2_symlink;
  117 static vop_write_t      ext2_write;
  118 static vop_vptofh_t     ext2_vptofh;
  119 static vop_close_t      ext2fifo_close;
  120 static vop_kqfilter_t   ext2fifo_kqfilter;
  121 
  122 /* Global vfs data structures for ext2. */
  123 struct vop_vector ext2_vnodeops = {
  124         .vop_default =          &default_vnodeops,
  125         .vop_access =           ext2_access,
  126         .vop_bmap =             ext2_bmap,
  127         .vop_cachedlookup =     ext2_lookup,
  128         .vop_close =            ext2_close,
  129         .vop_create =           ext2_create,
  130         .vop_fsync =            ext2_fsync,
  131         .vop_getpages =         ext2_getpages,
  132         .vop_getattr =          ext2_getattr,
  133         .vop_inactive =         ext2_inactive,
  134         .vop_ioctl =            ext2_ioctl,
  135         .vop_link =             ext2_link,
  136         .vop_lookup =           vfs_cache_lookup,
  137         .vop_mkdir =            ext2_mkdir,
  138         .vop_mknod =            ext2_mknod,
  139         .vop_open =             ext2_open,
  140         .vop_pathconf =         ext2_pathconf,
  141         .vop_poll =             vop_stdpoll,
  142         .vop_print =            ext2_print,
  143         .vop_read =             ext2_read,
  144         .vop_readdir =          ext2_readdir,
  145         .vop_readlink =         ext2_readlink,
  146         .vop_reallocblks =      ext2_reallocblks,
  147         .vop_reclaim =          ext2_reclaim,
  148         .vop_remove =           ext2_remove,
  149         .vop_rename =           ext2_rename,
  150         .vop_rmdir =            ext2_rmdir,
  151         .vop_setattr =          ext2_setattr,
  152         .vop_strategy =         ext2_strategy,
  153         .vop_symlink =          ext2_symlink,
  154         .vop_write =            ext2_write,
  155         .vop_vptofh =           ext2_vptofh,
  156 };
  157 
  158 struct vop_vector ext2_fifoops = {
  159         .vop_default =          &fifo_specops,
  160         .vop_access =           ext2_access,
  161         .vop_close =            ext2fifo_close,
  162         .vop_fsync =            ext2_fsync,
  163         .vop_getattr =          ext2_getattr,
  164         .vop_inactive =         ext2_inactive,
  165         .vop_kqfilter =         ext2fifo_kqfilter,
  166         .vop_print =            ext2_print,
  167         .vop_read =             VOP_PANIC,
  168         .vop_reclaim =          ext2_reclaim,
  169         .vop_setattr =          ext2_setattr,
  170         .vop_write =            VOP_PANIC,
  171         .vop_vptofh =           ext2_vptofh,
  172 };
  173 
  174 /*
  175  * A virgin directory (no blushing please).
  176  * Note that the type and namlen fields are reversed relative to ext2.
  177  * Also, we don't use `struct odirtemplate', since it would just cause
  178  * endianness problems.
  179  */
  180 static struct dirtemplate mastertemplate = {
  181         0, 12, 1, EXT2_FT_DIR, ".",
  182         0, DIRBLKSIZ - 12, 2, EXT2_FT_DIR, ".."
  183 };
  184 static struct dirtemplate omastertemplate = {
  185         0, 12, 1, EXT2_FT_UNKNOWN, ".",
  186         0, DIRBLKSIZ - 12, 2, EXT2_FT_UNKNOWN, ".."
  187 };
  188 
  189 static void
  190 ext2_itimes_locked(struct vnode *vp)
  191 {
  192         struct inode *ip;
  193         struct timespec ts;
  194 
  195         ASSERT_VI_LOCKED(vp, __func__);
  196 
  197         ip = VTOI(vp);
  198         if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE)) == 0)
  199                 return;
  200         if ((vp->v_type == VBLK || vp->v_type == VCHR))
  201                 ip->i_flag |= IN_LAZYMOD;
  202         else
  203                 ip->i_flag |= IN_MODIFIED;
  204         if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
  205                 vfs_timestamp(&ts);
  206                 if (ip->i_flag & IN_ACCESS) {
  207                         ip->i_atime = ts.tv_sec;
  208                         ip->i_atimensec = ts.tv_nsec;
  209                 }
  210                 if (ip->i_flag & IN_UPDATE) {
  211                         ip->i_mtime = ts.tv_sec;
  212                         ip->i_mtimensec = ts.tv_nsec;
  213                         ip->i_modrev++;
  214                 }
  215                 if (ip->i_flag & IN_CHANGE) {
  216                         ip->i_ctime = ts.tv_sec;
  217                         ip->i_ctimensec = ts.tv_nsec;
  218                 }
  219         }
  220         ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
  221 }
  222 
  223 void
  224 ext2_itimes(struct vnode *vp)
  225 {
  226 
  227         VI_LOCK(vp);
  228         ext2_itimes_locked(vp);
  229         VI_UNLOCK(vp);
  230 }
  231 
  232 /*
  233  * Create a regular file
  234  */
  235 static int
  236 ext2_create(struct vop_create_args *ap)
  237 {
  238         int error;
  239 
  240         error =
  241             ext2_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
  242             ap->a_dvp, ap->a_vpp, ap->a_cnp);
  243         if (error != 0)
  244                 return (error);
  245         if ((ap->a_cnp->cn_flags & MAKEENTRY) != 0)
  246                 cache_enter(ap->a_dvp, *ap->a_vpp, ap->a_cnp);
  247         return (0);
  248 }
  249 
  250 static int
  251 ext2_open(struct vop_open_args *ap)
  252 {
  253 
  254         if (ap->a_vp->v_type == VBLK || ap->a_vp->v_type == VCHR)
  255                 return (EOPNOTSUPP);
  256 
  257         /*
  258          * Files marked append-only must be opened for appending.
  259          */
  260         if ((VTOI(ap->a_vp)->i_flags & APPEND) &&
  261             (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
  262                 return (EPERM);
  263 
  264         vnode_create_vobject(ap->a_vp, VTOI(ap->a_vp)->i_size, ap->a_td);
  265 
  266         return (0);
  267 }
  268 
  269 /*
  270  * Close called.
  271  *
  272  * Update the times on the inode.
  273  */
  274 static int
  275 ext2_close(struct vop_close_args *ap)
  276 {
  277         struct vnode *vp = ap->a_vp;
  278 
  279         VI_LOCK(vp);
  280         if (vp->v_usecount > 1)
  281                 ext2_itimes_locked(vp);
  282         VI_UNLOCK(vp);
  283         return (0);
  284 }
  285 
  286 static int
  287 ext2_access(struct vop_access_args *ap)
  288 {
  289         struct vnode *vp = ap->a_vp;
  290         struct inode *ip = VTOI(vp);
  291         accmode_t accmode = ap->a_accmode;
  292         int error;
  293 
  294         if (vp->v_type == VBLK || vp->v_type == VCHR)
  295                 return (EOPNOTSUPP);
  296 
  297         /*
  298          * Disallow write attempts on read-only file systems;
  299          * unless the file is a socket, fifo, or a block or
  300          * character device resident on the file system.
  301          */
  302         if (accmode & VWRITE) {
  303                 switch (vp->v_type) {
  304                 case VDIR:
  305                 case VLNK:
  306                 case VREG:
  307                         if (vp->v_mount->mnt_flag & MNT_RDONLY)
  308                                 return (EROFS);
  309                         break;
  310                 default:
  311                         break;
  312                 }
  313         }
  314 
  315         /* If immutable bit set, nobody gets to write it. */
  316         if ((accmode & VWRITE) && (ip->i_flags & (SF_IMMUTABLE | SF_SNAPSHOT)))
  317                 return (EPERM);
  318 
  319         error = vaccess(vp->v_type, ip->i_mode, ip->i_uid, ip->i_gid,
  320             ap->a_accmode, ap->a_cred, NULL);
  321         return (error);
  322 }
  323 
  324 static int
  325 ext2_getattr(struct vop_getattr_args *ap)
  326 {
  327         struct vnode *vp = ap->a_vp;
  328         struct inode *ip = VTOI(vp);
  329         struct vattr *vap = ap->a_vap;
  330 
  331         ext2_itimes(vp);
  332         /*
  333          * Copy from inode table
  334          */
  335         vap->va_fsid = dev2udev(ip->i_devvp->v_rdev);
  336         vap->va_fileid = ip->i_number;
  337         vap->va_mode = ip->i_mode & ~IFMT;
  338         vap->va_nlink = ip->i_nlink;
  339         vap->va_uid = ip->i_uid;
  340         vap->va_gid = ip->i_gid;
  341         vap->va_rdev = ip->i_rdev;
  342         vap->va_size = ip->i_size;
  343         vap->va_atime.tv_sec = ip->i_atime;
  344         vap->va_atime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_atimensec : 0;
  345         vap->va_mtime.tv_sec = ip->i_mtime;
  346         vap->va_mtime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_mtimensec : 0;
  347         vap->va_ctime.tv_sec = ip->i_ctime;
  348         vap->va_ctime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_ctimensec : 0;
  349         if E2DI_HAS_XTIME(ip) {
  350                 vap->va_birthtime.tv_sec = ip->i_birthtime;
  351                 vap->va_birthtime.tv_nsec = ip->i_birthnsec;
  352         }
  353         vap->va_flags = ip->i_flags;
  354         vap->va_gen = ip->i_gen;
  355         vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
  356         vap->va_bytes = dbtob((u_quad_t)ip->i_blocks);
  357         vap->va_type = IFTOVT(ip->i_mode);
  358         vap->va_filerev = ip->i_modrev;
  359         return (0);
  360 }
  361 
  362 /*
  363  * Set attribute vnode op. called from several syscalls
  364  */
  365 static int
  366 ext2_setattr(struct vop_setattr_args *ap)
  367 {
  368         struct vattr *vap = ap->a_vap;
  369         struct vnode *vp = ap->a_vp;
  370         struct inode *ip = VTOI(vp);
  371         struct ucred *cred = ap->a_cred;
  372         struct thread *td = curthread;
  373         int error;
  374 
  375         /*
  376          * Check for unsettable attributes.
  377          */
  378         if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
  379             (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
  380             (vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
  381             ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
  382                 return (EINVAL);
  383         }
  384         if (vap->va_flags != VNOVAL) {
  385                 /* Disallow flags not supported by ext2fs. */
  386                 if (vap->va_flags & ~(SF_APPEND | SF_IMMUTABLE | UF_NODUMP))
  387                         return (EOPNOTSUPP);
  388 
  389                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  390                         return (EROFS);
  391                 /*
  392                  * Callers may only modify the file flags on objects they
  393                  * have VADMIN rights for.
  394                  */
  395                 if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
  396                         return (error);
  397                 /*
  398                  * Unprivileged processes and privileged processes in
  399                  * jail() are not permitted to unset system flags, or
  400                  * modify flags if any system flags are set.
  401                  * Privileged non-jail processes may not modify system flags
  402                  * if securelevel > 0 and any existing system flags are set.
  403                  */
  404                 if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) {
  405                         if (ip->i_flags & (SF_IMMUTABLE | SF_APPEND)) {
  406                                 error = securelevel_gt(cred, 0);
  407                                 if (error)
  408                                         return (error);
  409                         }
  410                 } else {
  411                         if (ip->i_flags & (SF_IMMUTABLE | SF_APPEND) ||
  412                             ((vap->va_flags ^ ip->i_flags) & SF_SETTABLE))
  413                                 return (EPERM);
  414                 }
  415                 ip->i_flags = vap->va_flags;
  416                 ip->i_flag |= IN_CHANGE;
  417                 if (ip->i_flags & (IMMUTABLE | APPEND))
  418                         return (0);
  419         }
  420         if (ip->i_flags & (IMMUTABLE | APPEND))
  421                 return (EPERM);
  422         /*
  423          * Go through the fields and update iff not VNOVAL.
  424          */
  425         if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
  426                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  427                         return (EROFS);
  428                 if ((error = ext2_chown(vp, vap->va_uid, vap->va_gid, cred,
  429                     td)) != 0)
  430                         return (error);
  431         }
  432         if (vap->va_size != VNOVAL) {
  433                 /*
  434                  * Disallow write attempts on read-only file systems;
  435                  * unless the file is a socket, fifo, or a block or
  436                  * character device resident on the file system.
  437                  */
  438                 switch (vp->v_type) {
  439                 case VDIR:
  440                         return (EISDIR);
  441                 case VLNK:
  442                 case VREG:
  443                         if (vp->v_mount->mnt_flag & MNT_RDONLY)
  444                                 return (EROFS);
  445                         break;
  446                 default:
  447                         break;
  448                 }
  449                 if ((error = ext2_truncate(vp, vap->va_size, 0, cred, td)) != 0)
  450                         return (error);
  451         }
  452         if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
  453                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  454                         return (EROFS);
  455                 /*
  456                  * From utimes(2):
  457                  * If times is NULL, ... The caller must be the owner of
  458                  * the file, have permission to write the file, or be the
  459                  * super-user.
  460                  * If times is non-NULL, ... The caller must be the owner of
  461                  * the file or be the super-user.
  462                  */
  463                 if ((error = VOP_ACCESS(vp, VADMIN, cred, td)) &&
  464                     ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
  465                     (error = VOP_ACCESS(vp, VWRITE, cred, td))))
  466                         return (error);
  467                 ip->i_flag |= IN_CHANGE | IN_MODIFIED;
  468                 if (vap->va_atime.tv_sec != VNOVAL) {
  469                         ip->i_flag &= ~IN_ACCESS;
  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_flag &= ~IN_UPDATE;
  475                         ip->i_mtime = vap->va_mtime.tv_sec;
  476                         ip->i_mtimensec = vap->va_mtime.tv_nsec;
  477                 }
  478                 ip->i_birthtime = vap->va_birthtime.tv_sec;
  479                 ip->i_birthnsec = vap->va_birthtime.tv_nsec;
  480                 error = ext2_update(vp, 0);
  481                 if (error)
  482                         return (error);
  483         }
  484         error = 0;
  485         if (vap->va_mode != (mode_t)VNOVAL) {
  486                 if (vp->v_mount->mnt_flag & MNT_RDONLY)
  487                         return (EROFS);
  488                 error = ext2_chmod(vp, (int)vap->va_mode, cred, td);
  489         }
  490         return (error);
  491 }
  492 
  493 /*
  494  * Change the mode on a file.
  495  * Inode must be locked before calling.
  496  */
  497 static int
  498 ext2_chmod(struct vnode *vp, int mode, struct ucred *cred, struct thread *td)
  499 {
  500         struct inode *ip = VTOI(vp);
  501         int error;
  502 
  503         /*
  504          * To modify the permissions on a file, must possess VADMIN
  505          * for that file.
  506          */
  507         if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
  508                 return (error);
  509         /*
  510          * Privileged processes may set the sticky bit on non-directories,
  511          * as well as set the setgid bit on a file with a group that the
  512          * process is not a member of.
  513          */
  514         if (vp->v_type != VDIR && (mode & S_ISTXT)) {
  515                 error = priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0);
  516                 if (error)
  517                         return (EFTYPE);
  518         }
  519         if (!groupmember(ip->i_gid, cred) && (mode & ISGID)) {
  520                 error = priv_check_cred(cred, PRIV_VFS_SETGID, 0);
  521                 if (error)
  522                         return (error);
  523         }
  524         ip->i_mode &= ~ALLPERMS;
  525         ip->i_mode |= (mode & ALLPERMS);
  526         ip->i_flag |= IN_CHANGE;
  527         return (0);
  528 }
  529 
  530 /*
  531  * Perform chown operation on inode ip;
  532  * inode must be locked prior to call.
  533  */
  534 static int
  535 ext2_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
  536     struct thread *td)
  537 {
  538         struct inode *ip = VTOI(vp);
  539         uid_t ouid;
  540         gid_t ogid;
  541         int error = 0;
  542 
  543         if (uid == (uid_t)VNOVAL)
  544                 uid = ip->i_uid;
  545         if (gid == (gid_t)VNOVAL)
  546                 gid = ip->i_gid;
  547         /*
  548          * To modify the ownership of a file, must possess VADMIN
  549          * for that file.
  550          */
  551         if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
  552                 return (error);
  553         /*
  554          * To change the owner of a file, or change the group of a file
  555          * to a group of which we are not a member, the caller must
  556          * have privilege.
  557          */
  558         if (uid != ip->i_uid || (gid != ip->i_gid &&
  559             !groupmember(gid, cred))) {
  560                 error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0);
  561                 if (error)
  562                         return (error);
  563         }
  564         ogid = ip->i_gid;
  565         ouid = ip->i_uid;
  566         ip->i_gid = gid;
  567         ip->i_uid = uid;
  568         ip->i_flag |= IN_CHANGE;
  569         if ((ip->i_mode & (ISUID | ISGID)) && (ouid != uid || ogid != gid)) {
  570                 if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0) != 0)
  571                         ip->i_mode &= ~(ISUID | ISGID);
  572         }
  573         return (0);
  574 }
  575 
  576 /*
  577  * Synch an open file.
  578  */
  579 /* ARGSUSED */
  580 static int
  581 ext2_fsync(struct vop_fsync_args *ap)
  582 {
  583         /*
  584          * Flush all dirty buffers associated with a vnode.
  585          */
  586 
  587         vop_stdfsync(ap);
  588 
  589         return (ext2_update(ap->a_vp, ap->a_waitfor == MNT_WAIT));
  590 }
  591 
  592 /*
  593  * Mknod vnode call
  594  */
  595 /* ARGSUSED */
  596 static int
  597 ext2_mknod(struct vop_mknod_args *ap)
  598 {
  599         struct vattr *vap = ap->a_vap;
  600         struct vnode **vpp = ap->a_vpp;
  601         struct inode *ip;
  602         ino_t ino;
  603         int error;
  604 
  605         error = ext2_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
  606             ap->a_dvp, vpp, ap->a_cnp);
  607         if (error)
  608                 return (error);
  609         ip = VTOI(*vpp);
  610         ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
  611         if (vap->va_rdev != VNOVAL) {
  612                 /*
  613                  * Want to be able to use this to make badblock
  614                  * inodes, so don't truncate the dev number.
  615                  */
  616                 ip->i_rdev = vap->va_rdev;
  617         }
  618         /*
  619          * Remove inode, then reload it through VFS_VGET so it is
  620          * checked to see if it is an alias of an existing entry in
  621          * the inode cache.      XXX I don't believe this is necessary now.
  622          */
  623         (*vpp)->v_type = VNON;
  624         ino = ip->i_number;     /* Save this before vgone() invalidates ip. */
  625         vgone(*vpp);
  626         vput(*vpp);
  627         error = VFS_VGET(ap->a_dvp->v_mount, ino, LK_EXCLUSIVE, vpp);
  628         if (error) {
  629                 *vpp = NULL;
  630                 return (error);
  631         }
  632         return (0);
  633 }
  634 
  635 static int
  636 ext2_remove(struct vop_remove_args *ap)
  637 {
  638         struct inode *ip;
  639         struct vnode *vp = ap->a_vp;
  640         struct vnode *dvp = ap->a_dvp;
  641         int error;
  642 
  643         ip = VTOI(vp);
  644         if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
  645             (VTOI(dvp)->i_flags & APPEND)) {
  646                 error = EPERM;
  647                 goto out;
  648         }
  649         error = ext2_dirremove(dvp, ap->a_cnp);
  650         if (error == 0) {
  651                 ip->i_nlink--;
  652                 ip->i_flag |= IN_CHANGE;
  653         }
  654 out:
  655         return (error);
  656 }
  657 
  658 /*
  659  * link vnode call
  660  */
  661 static int
  662 ext2_link(struct vop_link_args *ap)
  663 {
  664         struct vnode *vp = ap->a_vp;
  665         struct vnode *tdvp = ap->a_tdvp;
  666         struct componentname *cnp = ap->a_cnp;
  667         struct inode *ip;
  668         int error;
  669 
  670 #ifdef INVARIANTS
  671         if ((cnp->cn_flags & HASBUF) == 0)
  672                 panic("ext2_link: no name");
  673 #endif
  674         ip = VTOI(vp);
  675         if ((nlink_t)ip->i_nlink >= EXT2_LINK_MAX) {
  676                 error = EMLINK;
  677                 goto out;
  678         }
  679         if (ip->i_flags & (IMMUTABLE | APPEND)) {
  680                 error = EPERM;
  681                 goto out;
  682         }
  683         ip->i_nlink++;
  684         ip->i_flag |= IN_CHANGE;
  685         error = ext2_update(vp, !DOINGASYNC(vp));
  686         if (!error)
  687                 error = ext2_direnter(ip, tdvp, cnp);
  688         if (error) {
  689                 ip->i_nlink--;
  690                 ip->i_flag |= IN_CHANGE;
  691         }
  692 out:
  693         return (error);
  694 }
  695 
  696 /*
  697  * Rename system call.
  698  *      rename("foo", "bar");
  699  * is essentially
  700  *      unlink("bar");
  701  *      link("foo", "bar");
  702  *      unlink("foo");
  703  * but ``atomically''.  Can't do full commit without saving state in the
  704  * inode on disk which isn't feasible at this time.  Best we can do is
  705  * always guarantee the target exists.
  706  *
  707  * Basic algorithm is:
  708  *
  709  * 1) Bump link count on source while we're linking it to the
  710  *    target.  This also ensure the inode won't be deleted out
  711  *    from underneath us while we work (it may be truncated by
  712  *    a concurrent `trunc' or `open' for creation).
  713  * 2) Link source to destination.  If destination already exists,
  714  *    delete it first.
  715  * 3) Unlink source reference to inode if still around. If a
  716  *    directory was moved and the parent of the destination
  717  *    is different from the source, patch the ".." entry in the
  718  *    directory.
  719  */
  720 static int
  721 ext2_rename(struct vop_rename_args *ap)
  722 {
  723         struct vnode *tvp = ap->a_tvp;
  724         struct vnode *tdvp = ap->a_tdvp;
  725         struct vnode *fvp = ap->a_fvp;
  726         struct vnode *fdvp = ap->a_fdvp;
  727         struct componentname *tcnp = ap->a_tcnp;
  728         struct componentname *fcnp = ap->a_fcnp;
  729         struct inode *ip, *xp, *dp;
  730         struct dirtemplate dirbuf;
  731         int doingdirectory = 0, oldparent = 0, newparent = 0;
  732         int error = 0;
  733         u_char namlen;
  734 
  735 #ifdef INVARIANTS
  736         if ((tcnp->cn_flags & HASBUF) == 0 ||
  737             (fcnp->cn_flags & HASBUF) == 0)
  738                 panic("ext2_rename: no name");
  739 #endif
  740         /*
  741          * Check for cross-device rename.
  742          */
  743         if ((fvp->v_mount != tdvp->v_mount) ||
  744             (tvp && (fvp->v_mount != tvp->v_mount))) {
  745                 error = EXDEV;
  746 abortit:
  747                 if (tdvp == tvp)
  748                         vrele(tdvp);
  749                 else
  750                         vput(tdvp);
  751                 if (tvp)
  752                         vput(tvp);
  753                 vrele(fdvp);
  754                 vrele(fvp);
  755                 return (error);
  756         }
  757 
  758         if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
  759             (VTOI(tdvp)->i_flags & APPEND))) {
  760                 error = EPERM;
  761                 goto abortit;
  762         }
  763 
  764         /*
  765          * Renaming a file to itself has no effect.  The upper layers should
  766          * not call us in that case.  Temporarily just warn if they do.
  767          */
  768         if (fvp == tvp) {
  769                 printf("ext2_rename: fvp == tvp (can't happen)\n");
  770                 error = 0;
  771                 goto abortit;
  772         }
  773 
  774         if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
  775                 goto abortit;
  776         dp = VTOI(fdvp);
  777         ip = VTOI(fvp);
  778         if (ip->i_nlink >= EXT2_LINK_MAX) {
  779                 VOP_UNLOCK(fvp, 0);
  780                 error = EMLINK;
  781                 goto abortit;
  782         }
  783         if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
  784             || (dp->i_flags & APPEND)) {
  785                 VOP_UNLOCK(fvp, 0);
  786                 error = EPERM;
  787                 goto abortit;
  788         }
  789         if ((ip->i_mode & IFMT) == IFDIR) {
  790                 /*
  791                  * Avoid ".", "..", and aliases of "." for obvious reasons.
  792                  */
  793                 if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
  794                     dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & ISDOTDOT ||
  795                     (ip->i_flag & IN_RENAME)) {
  796                         VOP_UNLOCK(fvp, 0);
  797                         error = EINVAL;
  798                         goto abortit;
  799                 }
  800                 ip->i_flag |= IN_RENAME;
  801                 oldparent = dp->i_number;
  802                 doingdirectory++;
  803         }
  804         vrele(fdvp);
  805 
  806         /*
  807          * When the target exists, both the directory
  808          * and target vnodes are returned locked.
  809          */
  810         dp = VTOI(tdvp);
  811         xp = NULL;
  812         if (tvp)
  813                 xp = VTOI(tvp);
  814 
  815         /*
  816          * 1) Bump link count while we're moving stuff
  817          *    around.  If we crash somewhere before
  818          *    completing our work, the link count
  819          *    may be wrong, but correctable.
  820          */
  821         ip->i_nlink++;
  822         ip->i_flag |= IN_CHANGE;
  823         if ((error = ext2_update(fvp, !DOINGASYNC(fvp))) != 0) {
  824                 VOP_UNLOCK(fvp, 0);
  825                 goto bad;
  826         }
  827 
  828         /*
  829          * If ".." must be changed (ie the directory gets a new
  830          * parent) then the source directory must not be in the
  831          * directory hierarchy above the target, as this would
  832          * orphan everything below the source directory. Also
  833          * the user must have write permission in the source so
  834          * as to be able to change "..". We must repeat the call
  835          * to namei, as the parent directory is unlocked by the
  836          * call to checkpath().
  837          */
  838         error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_thread);
  839         VOP_UNLOCK(fvp, 0);
  840         if (oldparent != dp->i_number)
  841                 newparent = dp->i_number;
  842         if (doingdirectory && newparent) {
  843                 if (error)      /* write access check above */
  844                         goto bad;
  845                 if (xp != NULL)
  846                         vput(tvp);
  847                 error = ext2_checkpath(ip, dp, tcnp->cn_cred);
  848                 if (error)
  849                         goto out;
  850                 VREF(tdvp);
  851                 error = relookup(tdvp, &tvp, tcnp);
  852                 if (error)
  853                         goto out;
  854                 vrele(tdvp);
  855                 dp = VTOI(tdvp);
  856                 xp = NULL;
  857                 if (tvp)
  858                         xp = VTOI(tvp);
  859         }
  860         /*
  861          * 2) If target doesn't exist, link the target
  862          *    to the source and unlink the source.
  863          *    Otherwise, rewrite the target directory
  864          *    entry to reference the source inode and
  865          *    expunge the original entry's existence.
  866          */
  867         if (xp == NULL) {
  868                 if (dp->i_devvp != ip->i_devvp)
  869                         panic("ext2_rename: EXDEV");
  870                 /*
  871                  * Account for ".." in new directory.
  872                  * When source and destination have the same
  873                  * parent we don't fool with the link count.
  874                  */
  875                 if (doingdirectory && newparent) {
  876                         if ((nlink_t)dp->i_nlink >= EXT2_LINK_MAX) {
  877                                 error = EMLINK;
  878                                 goto bad;
  879                         }
  880                         dp->i_nlink++;
  881                         dp->i_flag |= IN_CHANGE;
  882                         error = ext2_update(tdvp, !DOINGASYNC(tdvp));
  883                         if (error)
  884                                 goto bad;
  885                 }
  886                 error = ext2_direnter(ip, tdvp, tcnp);
  887                 if (error) {
  888                         if (doingdirectory && newparent) {
  889                                 dp->i_nlink--;
  890                                 dp->i_flag |= IN_CHANGE;
  891                                 (void)ext2_update(tdvp, 1);
  892                         }
  893                         goto bad;
  894                 }
  895                 vput(tdvp);
  896         } else {
  897                 if (xp->i_devvp != dp->i_devvp || xp->i_devvp != ip->i_devvp)
  898                         panic("ext2_rename: EXDEV");
  899                 /*
  900                  * Short circuit rename(foo, foo).
  901                  */
  902                 if (xp->i_number == ip->i_number)
  903                         panic("ext2_rename: same file");
  904                 /*
  905                  * If the parent directory is "sticky", then the user must
  906                  * own the parent directory, or the destination of the rename,
  907                  * otherwise the destination may not be changed (except by
  908                  * root). This implements append-only directories.
  909                  */
  910                 if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
  911                     tcnp->cn_cred->cr_uid != dp->i_uid &&
  912                     xp->i_uid != tcnp->cn_cred->cr_uid) {
  913                         error = EPERM;
  914                         goto bad;
  915                 }
  916                 /*
  917                  * Target must be empty if a directory and have no links
  918                  * to it. Also, ensure source and target are compatible
  919                  * (both directories, or both not directories).
  920                  */
  921                 if ((xp->i_mode & IFMT) == IFDIR) {
  922                         if (!ext2_dirempty(xp, dp->i_number, tcnp->cn_cred) ||
  923                             xp->i_nlink > 2) {
  924                                 error = ENOTEMPTY;
  925                                 goto bad;
  926                         }
  927                         if (!doingdirectory) {
  928                                 error = ENOTDIR;
  929                                 goto bad;
  930                         }
  931                         cache_purge(tdvp);
  932                 } else if (doingdirectory) {
  933                         error = EISDIR;
  934                         goto bad;
  935                 }
  936                 error = ext2_dirrewrite(dp, ip, tcnp);
  937                 if (error)
  938                         goto bad;
  939                 /*
  940                  * If the target directory is in the same
  941                  * directory as the source directory,
  942                  * decrement the link count on the parent
  943                  * of the target directory.
  944                  */
  945                 if (doingdirectory && !newparent) {
  946                         dp->i_nlink--;
  947                         dp->i_flag |= IN_CHANGE;
  948                 }
  949                 vput(tdvp);
  950                 /*
  951                  * Adjust the link count of the target to
  952                  * reflect the dirrewrite above.  If this is
  953                  * a directory it is empty and there are
  954                  * no links to it, so we can squash the inode and
  955                  * any space associated with it.  We disallowed
  956                  * renaming over top of a directory with links to
  957                  * it above, as the remaining link would point to
  958                  * a directory without "." or ".." entries.
  959                  */
  960                 xp->i_nlink--;
  961                 if (doingdirectory) {
  962                         if (--xp->i_nlink != 0)
  963                                 panic("ext2_rename: linked directory");
  964                         error = ext2_truncate(tvp, (off_t)0, IO_SYNC,
  965                             tcnp->cn_cred, tcnp->cn_thread);
  966                 }
  967                 xp->i_flag |= IN_CHANGE;
  968                 vput(tvp);
  969                 xp = NULL;
  970         }
  971 
  972         /*
  973          * 3) Unlink the source.
  974          */
  975         fcnp->cn_flags &= ~MODMASK;
  976         fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
  977         VREF(fdvp);
  978         error = relookup(fdvp, &fvp, fcnp);
  979         if (error == 0)
  980                 vrele(fdvp);
  981         if (fvp != NULL) {
  982                 xp = VTOI(fvp);
  983                 dp = VTOI(fdvp);
  984         } else {
  985                 /*
  986                  * From name has disappeared.  IN_RENAME is not sufficient
  987                  * to protect against directory races due to timing windows,
  988                  * so we can't panic here.
  989                  */
  990                 vrele(ap->a_fvp);
  991                 return (0);
  992         }
  993         /*
  994          * Ensure that the directory entry still exists and has not
  995          * changed while the new name has been entered. If the source is
  996          * a file then the entry may have been unlinked or renamed. In
  997          * either case there is no further work to be done. If the source
  998          * is a directory then it cannot have been rmdir'ed; its link
  999          * count of three would cause a rmdir to fail with ENOTEMPTY.
 1000          * The IN_RENAME flag ensures that it cannot be moved by another
 1001          * rename.
 1002          */
 1003         if (xp != ip) {
 1004                 /*
 1005                  * From name resolves to a different inode.  IN_RENAME is
 1006                  * not sufficient protection against timing window races
 1007                  * so we can't panic here.
 1008                  */
 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         /*
 1161          * note that in ext2 DIRBLKSIZ == blocksize, not DEV_BSIZE so let's
 1162          * just redefine it - for this function only
 1163          */
 1164 #undef  DIRBLKSIZ
 1165 #define DIRBLKSIZ  VTOI(dvp)->i_e2fs->e2fs_bsize
 1166         dirtemplate.dotdot_reclen = DIRBLKSIZ - 12;
 1167         error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)&dirtemplate,
 1168             sizeof(dirtemplate), (off_t)0, UIO_SYSSPACE,
 1169             IO_NODELOCKED | IO_SYNC | IO_NOMACCHECK, cnp->cn_cred, NOCRED,
 1170             NULL, NULL);
 1171         if (error) {
 1172                 dp->i_nlink--;
 1173                 dp->i_flag |= IN_CHANGE;
 1174                 goto bad;
 1175         }
 1176         if (DIRBLKSIZ > VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
 1177                 /* XXX should grow with balloc() */
 1178                 panic("ext2_mkdir: blksize");
 1179         else {
 1180                 ip->i_size = DIRBLKSIZ;
 1181                 ip->i_flag |= IN_CHANGE;
 1182         }
 1183 
 1184         /* Directory set up, now install its entry in the parent directory. */
 1185         error = ext2_direnter(ip, dvp, cnp);
 1186         if (error) {
 1187                 dp->i_nlink--;
 1188                 dp->i_flag |= IN_CHANGE;
 1189         }
 1190 bad:
 1191         /*
 1192          * No need to do an explicit VOP_TRUNCATE here, vrele will do this
 1193          * for us because we set the link count to 0.
 1194          */
 1195         if (error) {
 1196                 ip->i_nlink = 0;
 1197                 ip->i_flag |= IN_CHANGE;
 1198                 vput(tvp);
 1199         } else
 1200                 *ap->a_vpp = tvp;
 1201 out:
 1202         return (error);
 1203 #undef  DIRBLKSIZ
 1204 #define DIRBLKSIZ  DEV_BSIZE
 1205 }
 1206 
 1207 /*
 1208  * Rmdir system call.
 1209  */
 1210 static int
 1211 ext2_rmdir(struct vop_rmdir_args *ap)
 1212 {
 1213         struct vnode *vp = ap->a_vp;
 1214         struct vnode *dvp = ap->a_dvp;
 1215         struct componentname *cnp = ap->a_cnp;
 1216         struct inode *ip, *dp;
 1217         int error;
 1218 
 1219         ip = VTOI(vp);
 1220         dp = VTOI(dvp);
 1221 
 1222         /*
 1223          * Verify the directory is empty (and valid).
 1224          * (Rmdir ".." won't be valid since
 1225          *  ".." will contain a reference to
 1226          *  the current directory and thus be
 1227          *  non-empty.)
 1228          */
 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 bufobj *bo;
 1335         daddr_t blkno;
 1336         int error;
 1337 
 1338         if (vp->v_type == VBLK || vp->v_type == VCHR)
 1339                 panic("ext2_strategy: spec");
 1340         if (bp->b_blkno == bp->b_lblkno) {
 1341                 error = ext2_bmaparray(vp, bp->b_lblkno, &blkno, NULL, NULL);
 1342                 bp->b_blkno = blkno;
 1343                 if (error) {
 1344                         bp->b_error = error;
 1345                         bp->b_ioflags |= BIO_ERROR;
 1346                         bufdone(bp);
 1347                         return (0);
 1348                 }
 1349                 if ((long)bp->b_blkno == -1)
 1350                         vfs_bio_clrbuf(bp);
 1351         }
 1352         if ((long)bp->b_blkno == -1) {
 1353                 bufdone(bp);
 1354                 return (0);
 1355         }
 1356         bp->b_iooffset = dbtob(bp->b_blkno);
 1357         bo = VFSTOEXT2(vp->v_mount)->um_bo;
 1358         BO_STRATEGY(bo, bp);
 1359         return (0);
 1360 }
 1361 
 1362 /*
 1363  * Print out the contents of an inode.
 1364  */
 1365 static int
 1366 ext2_print(struct vop_print_args *ap)
 1367 {
 1368         struct vnode *vp = ap->a_vp;
 1369         struct inode *ip = VTOI(vp);
 1370 
 1371         vn_printf(ip->i_devvp, "\tino %lu", (u_long)ip->i_number);
 1372         if (vp->v_type == VFIFO)
 1373                 fifo_printinfo(vp);
 1374         printf("\n");
 1375         return (0);
 1376 }
 1377 
 1378 /*
 1379  * Close wrapper for fifos.
 1380  *
 1381  * Update the times on the inode then do device close.
 1382  */
 1383 static int
 1384 ext2fifo_close(struct vop_close_args *ap)
 1385 {
 1386         struct vnode *vp = ap->a_vp;
 1387 
 1388         VI_LOCK(vp);
 1389         if (vp->v_usecount > 1)
 1390                 ext2_itimes_locked(vp);
 1391         VI_UNLOCK(vp);
 1392         return (fifo_specops.vop_close(ap));
 1393 }
 1394 
 1395 /*
 1396  * Kqfilter wrapper for fifos.
 1397  *
 1398  * Fall through to ext2 kqfilter routines if needed
 1399  */
 1400 static int
 1401 ext2fifo_kqfilter(struct vop_kqfilter_args *ap)
 1402 {
 1403         int error;
 1404 
 1405         error = fifo_specops.vop_kqfilter(ap);
 1406         if (error)
 1407                 error = vfs_kqfilter(ap);
 1408         return (error);
 1409 }
 1410 
 1411 /*
 1412  * Return POSIX pathconf information applicable to ext2 filesystems.
 1413  */
 1414 static int
 1415 ext2_pathconf(struct vop_pathconf_args *ap)
 1416 {
 1417         int error = 0;
 1418 
 1419         switch (ap->a_name) {
 1420         case _PC_LINK_MAX:
 1421                 *ap->a_retval = EXT2_LINK_MAX;
 1422                 break;
 1423         case _PC_NAME_MAX:
 1424                 *ap->a_retval = NAME_MAX;
 1425                 break;
 1426         case _PC_PATH_MAX:
 1427                 *ap->a_retval = PATH_MAX;
 1428                 break;
 1429         case _PC_PIPE_BUF:
 1430                 *ap->a_retval = PIPE_BUF;
 1431                 break;
 1432         case _PC_CHOWN_RESTRICTED:
 1433                 *ap->a_retval = 1;
 1434                 break;
 1435         case _PC_NO_TRUNC:
 1436                 *ap->a_retval = 1;
 1437                 break;
 1438         case _PC_MIN_HOLE_SIZE:
 1439                 *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
 1440                 break;
 1441         case _PC_ASYNC_IO:
 1442                 /* _PC_ASYNC_IO should have been handled by upper layers. */
 1443                 KASSERT(0, ("_PC_ASYNC_IO should not get here"));
 1444                 error = EINVAL;
 1445                 break;
 1446         case _PC_PRIO_IO:
 1447                 *ap->a_retval = 0;
 1448                 break;
 1449         case _PC_SYNC_IO:
 1450                 *ap->a_retval = 0;
 1451                 break;
 1452         case _PC_ALLOC_SIZE_MIN:
 1453                 *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_bsize;
 1454                 break;
 1455         case _PC_FILESIZEBITS:
 1456                 *ap->a_retval = 64;
 1457                 break;
 1458         case _PC_REC_INCR_XFER_SIZE:
 1459                 *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
 1460                 break;
 1461         case _PC_REC_MAX_XFER_SIZE:
 1462                 *ap->a_retval = -1;     /* means ``unlimited'' */
 1463                 break;
 1464         case _PC_REC_MIN_XFER_SIZE:
 1465                 *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
 1466                 break;
 1467         case _PC_REC_XFER_ALIGN:
 1468                 *ap->a_retval = PAGE_SIZE;
 1469                 break;
 1470         case _PC_SYMLINK_MAX:
 1471                 *ap->a_retval = MAXPATHLEN;
 1472                 break;
 1473 
 1474         default:
 1475                 error = EINVAL;
 1476                 break;
 1477         }
 1478         return (error);
 1479 }
 1480 
 1481 /*
 1482  * Vnode pointer to File handle
 1483  */
 1484 /* ARGSUSED */
 1485 static int
 1486 ext2_vptofh(struct vop_vptofh_args *ap)
 1487 {
 1488         struct inode *ip;
 1489         struct ufid *ufhp;
 1490 
 1491         ip = VTOI(ap->a_vp);
 1492         ufhp = (struct ufid *)ap->a_fhp;
 1493         ufhp->ufid_len = sizeof(struct ufid);
 1494         ufhp->ufid_ino = ip->i_number;
 1495         ufhp->ufid_gen = ip->i_gen;
 1496         return (0);
 1497 }
 1498 
 1499 /*
 1500  * Initialize the vnode associated with a new inode, handle aliased
 1501  * vnodes.
 1502  */
 1503 int
 1504 ext2_vinit(struct mount *mntp, struct vop_vector *fifoops, struct vnode **vpp)
 1505 {
 1506         struct inode *ip;
 1507         struct vnode *vp;
 1508 
 1509         vp = *vpp;
 1510         ip = VTOI(vp);
 1511         vp->v_type = IFTOVT(ip->i_mode);
 1512         if (vp->v_type == VFIFO)
 1513                 vp->v_op = fifoops;
 1514 
 1515         if (ip->i_number == EXT2_ROOTINO)
 1516                 vp->v_vflag |= VV_ROOT;
 1517         ip->i_modrev = init_va_filerev();
 1518         *vpp = vp;
 1519         return (0);
 1520 }
 1521 
 1522 /*
 1523  * Allocate a new inode.
 1524  */
 1525 static int
 1526 ext2_makeinode(int mode, struct vnode *dvp, struct vnode **vpp,
 1527     struct componentname *cnp)
 1528 {
 1529         struct inode *ip, *pdir;
 1530         struct vnode *tvp;
 1531         int error;
 1532 
 1533         pdir = VTOI(dvp);
 1534 #ifdef INVARIANTS
 1535         if ((cnp->cn_flags & HASBUF) == 0)
 1536                 panic("ext2_makeinode: no name");
 1537 #endif
 1538         *vpp = NULL;
 1539         if ((mode & IFMT) == 0)
 1540                 mode |= IFREG;
 1541 
 1542         error = ext2_valloc(dvp, mode, cnp->cn_cred, &tvp);
 1543         if (error) {
 1544                 return (error);
 1545         }
 1546         ip = VTOI(tvp);
 1547         ip->i_gid = pdir->i_gid;
 1548 #ifdef SUIDDIR
 1549         {
 1550                 /*
 1551                  * if we are
 1552                  * not the owner of the directory,
 1553                  * and we are hacking owners here, (only do this where told to)
 1554                  * and we are not giving it TOO root, (would subvert quotas)
 1555                  * then go ahead and give it to the other user.
 1556                  * Note that this drops off the execute bits for security.
 1557                  */
 1558                 if ((dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
 1559                     (pdir->i_mode & ISUID) &&
 1560                     (pdir->i_uid != cnp->cn_cred->cr_uid) && pdir->i_uid) {
 1561                         ip->i_uid = pdir->i_uid;
 1562                         mode &= ~07111;
 1563                 } else {
 1564                         ip->i_uid = cnp->cn_cred->cr_uid;
 1565                 }
 1566         }
 1567 #else
 1568         ip->i_uid = cnp->cn_cred->cr_uid;
 1569 #endif
 1570         ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
 1571         ip->i_mode = mode;
 1572         tvp->v_type = IFTOVT(mode);     /* Rest init'd in getnewvnode(). */
 1573         ip->i_nlink = 1;
 1574         if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred)) {
 1575                 if (priv_check_cred(cnp->cn_cred, PRIV_VFS_RETAINSUGID, 0))
 1576                         ip->i_mode &= ~ISGID;
 1577         }
 1578 
 1579         if (cnp->cn_flags & ISWHITEOUT)
 1580                 ip->i_flags |= UF_OPAQUE;
 1581 
 1582         /*
 1583          * Make sure inode goes to disk before directory entry.
 1584          */
 1585         error = ext2_update(tvp, !DOINGASYNC(tvp));
 1586         if (error)
 1587                 goto bad;
 1588         error = ext2_direnter(ip, dvp, cnp);
 1589         if (error)
 1590                 goto bad;
 1591 
 1592         *vpp = tvp;
 1593         return (0);
 1594 
 1595 bad:
 1596         /*
 1597          * Write error occurred trying to update the inode
 1598          * or the directory so must deallocate the inode.
 1599          */
 1600         ip->i_nlink = 0;
 1601         ip->i_flag |= IN_CHANGE;
 1602         vput(tvp);
 1603         return (error);
 1604 }
 1605 
 1606 /*
 1607  * Vnode op for reading.
 1608  */
 1609 static int
 1610 ext2_read(struct vop_read_args *ap)
 1611 {
 1612         struct vnode *vp;
 1613         struct inode *ip;
 1614         int error;
 1615 
 1616         vp = ap->a_vp;
 1617         ip = VTOI(vp);
 1618 
 1619         /* EXT4_EXT_LOCK(ip); */
 1620         if (ip->i_flag & IN_E4EXTENTS)
 1621                 error = ext4_ext_read(ap);
 1622         else
 1623                 error = ext2_ind_read(ap);
 1624         /* EXT4_EXT_UNLOCK(ip); */
 1625         return (error);
 1626 }
 1627 
 1628 /*
 1629  * Vnode op for reading.
 1630  */
 1631 static int
 1632 ext2_ind_read(struct vop_read_args *ap)
 1633 {
 1634         struct vnode *vp;
 1635         struct inode *ip;
 1636         struct uio *uio;
 1637         struct m_ext2fs *fs;
 1638         struct buf *bp;
 1639         daddr_t lbn, nextlbn;
 1640         off_t bytesinfile;
 1641         long size, xfersize, blkoffset;
 1642         int error, orig_resid, seqcount;
 1643         int ioflag;
 1644 
 1645         vp = ap->a_vp;
 1646         uio = ap->a_uio;
 1647         ioflag = ap->a_ioflag;
 1648 
 1649         seqcount = ap->a_ioflag >> IO_SEQSHIFT;
 1650         ip = VTOI(vp);
 1651 
 1652 #ifdef INVARIANTS
 1653         if (uio->uio_rw != UIO_READ)
 1654                 panic("%s: mode", "ext2_read");
 1655 
 1656         if (vp->v_type == VLNK) {
 1657                 if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
 1658                         panic("%s: short symlink", "ext2_read");
 1659         } else if (vp->v_type != VREG && vp->v_type != VDIR)
 1660                 panic("%s: type %d", "ext2_read", vp->v_type);
 1661 #endif
 1662         orig_resid = uio->uio_resid;
 1663         KASSERT(orig_resid >= 0, ("ext2_read: uio->uio_resid < 0"));
 1664         if (orig_resid == 0)
 1665                 return (0);
 1666         KASSERT(uio->uio_offset >= 0, ("ext2_read: uio->uio_offset < 0"));
 1667         fs = ip->i_e2fs;
 1668         if (uio->uio_offset < ip->i_size &&
 1669             uio->uio_offset >= fs->e2fs_maxfilesize)
 1670                 return (EOVERFLOW);
 1671 
 1672         for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
 1673                 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
 1674                         break;
 1675                 lbn = lblkno(fs, uio->uio_offset);
 1676                 nextlbn = lbn + 1;
 1677                 size = blksize(fs, ip, lbn);
 1678                 blkoffset = blkoff(fs, uio->uio_offset);
 1679 
 1680                 xfersize = fs->e2fs_fsize - blkoffset;
 1681                 if (uio->uio_resid < xfersize)
 1682                         xfersize = uio->uio_resid;
 1683                 if (bytesinfile < xfersize)
 1684                         xfersize = bytesinfile;
 1685 
 1686                 if (lblktosize(fs, nextlbn) >= ip->i_size)
 1687                         error = bread(vp, lbn, size, NOCRED, &bp);
 1688                 else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
 1689                         error = cluster_read(vp, ip->i_size, lbn, size,
 1690                             NOCRED, blkoffset + uio->uio_resid, seqcount,
 1691                             0, &bp);
 1692                 } else if (seqcount > 1) {
 1693                         u_int nextsize = blksize(fs, ip, nextlbn);
 1694 
 1695                         error = breadn(vp, lbn,
 1696                             size, &nextlbn, &nextsize, 1, NOCRED, &bp);
 1697                 } else
 1698                         error = bread(vp, lbn, size, NOCRED, &bp);
 1699                 if (error) {
 1700                         brelse(bp);
 1701                         bp = NULL;
 1702                         break;
 1703                 }
 1704 
 1705                 /*
 1706                  * If IO_DIRECT then set B_DIRECT for the buffer.  This
 1707                  * will cause us to attempt to release the buffer later on
 1708                  * and will cause the buffer cache to attempt to free the
 1709                  * underlying pages.
 1710                  */
 1711                 if (ioflag & IO_DIRECT)
 1712                         bp->b_flags |= B_DIRECT;
 1713 
 1714                 /*
 1715                  * We should only get non-zero b_resid when an I/O error
 1716                  * has occurred, which should cause us to break above.
 1717                  * However, if the short read did not cause an error,
 1718                  * then we want to ensure that we do not uiomove bad
 1719                  * or uninitialized data.
 1720                  */
 1721                 size -= bp->b_resid;
 1722                 if (size < xfersize) {
 1723                         if (size == 0)
 1724                                 break;
 1725                         xfersize = size;
 1726                 }
 1727                 error = uiomove((char *)bp->b_data + blkoffset,
 1728                     (int)xfersize, uio);
 1729                 if (error)
 1730                         break;
 1731 
 1732                 if (ioflag & (IO_VMIO|IO_DIRECT)) {
 1733                         /*
 1734                          * If it's VMIO or direct I/O, then we don't
 1735                          * need the buf, mark it available for
 1736                          * freeing. If it's non-direct VMIO, the VM has
 1737                          * the data.
 1738                          */
 1739                         bp->b_flags |= B_RELBUF;
 1740                         brelse(bp);
 1741                 } else {
 1742                         /*
 1743                          * Otherwise let whoever
 1744                          * made the request take care of
 1745                          * freeing it. We just queue
 1746                          * it onto another list.
 1747                          */
 1748                         bqrelse(bp);
 1749                 }
 1750         }
 1751 
 1752         /*
 1753          * This can only happen in the case of an error because the loop
 1754          * above resets bp to NULL on each iteration and on normal
 1755          * completion has not set a new value into it. so it must have come
 1756          * from a 'break' statement
 1757          */
 1758         if (bp != NULL) {
 1759                 if (ioflag & (IO_VMIO|IO_DIRECT)) {
 1760                         bp->b_flags |= B_RELBUF;
 1761                         brelse(bp);
 1762                 } else {
 1763                         bqrelse(bp);
 1764                 }
 1765         }
 1766 
 1767         if ((error == 0 || uio->uio_resid != orig_resid) &&
 1768             (vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
 1769                 ip->i_flag |= IN_ACCESS;
 1770         return (error);
 1771 }
 1772 
 1773 static int
 1774 ext2_ioctl(struct vop_ioctl_args *ap)
 1775 {
 1776 
 1777         switch (ap->a_command) {
 1778         case FIOSEEKDATA:
 1779         case FIOSEEKHOLE:
 1780                 return (vn_bmap_seekhole(ap->a_vp, ap->a_command,
 1781                     (off_t *)ap->a_data, ap->a_cred));
 1782         default:
 1783                 return (ENOTTY);
 1784         }
 1785 }
 1786 
 1787 /*
 1788  * this function handles ext4 extents block mapping
 1789  */
 1790 static int
 1791 ext4_ext_read(struct vop_read_args *ap)
 1792 {
 1793         struct vnode *vp;
 1794         struct inode *ip;
 1795         struct uio *uio;
 1796         struct m_ext2fs *fs;
 1797         struct buf *bp;
 1798         struct ext4_extent nex, *ep;
 1799         struct ext4_extent_path path;
 1800         daddr_t lbn, newblk;
 1801         off_t bytesinfile;
 1802         int cache_type;
 1803         ssize_t orig_resid;
 1804         int error;
 1805         long size, xfersize, blkoffset;
 1806 
 1807         vp = ap->a_vp;
 1808         ip = VTOI(vp);
 1809         uio = ap->a_uio;
 1810         memset(&path, 0, sizeof(path));
 1811 
 1812         orig_resid = uio->uio_resid;
 1813         KASSERT(orig_resid >= 0, ("%s: uio->uio_resid < 0", __func__));
 1814         if (orig_resid == 0)
 1815                 return (0);
 1816         KASSERT(uio->uio_offset >= 0, ("%s: uio->uio_offset < 0", __func__));
 1817         fs = ip->i_e2fs;
 1818         if (uio->uio_offset < ip->i_size && uio->uio_offset >= fs->e2fs_maxfilesize)
 1819                 return (EOVERFLOW);
 1820 
 1821         while (uio->uio_resid > 0) {
 1822                 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
 1823                         break;
 1824                 lbn = lblkno(fs, uio->uio_offset);
 1825                 size = blksize(fs, ip, lbn);
 1826                 blkoffset = blkoff(fs, uio->uio_offset);
 1827 
 1828                 xfersize = fs->e2fs_fsize - blkoffset;
 1829                 xfersize = MIN(xfersize, uio->uio_resid);
 1830                 xfersize = MIN(xfersize, bytesinfile);
 1831 
 1832                 /* get block from ext4 extent cache */
 1833                 cache_type = ext4_ext_in_cache(ip, lbn, &nex);
 1834                 switch (cache_type) {
 1835                 case EXT4_EXT_CACHE_NO:
 1836                         ext4_ext_find_extent(fs, ip, lbn, &path);
 1837                         ep = path.ep_ext;
 1838                         if (ep == NULL)
 1839                                 return (EIO);
 1840 
 1841                         ext4_ext_put_cache(ip, ep, EXT4_EXT_CACHE_IN);
 1842 
 1843                         newblk = lbn - ep->e_blk + (ep->e_start_lo |
 1844                             (daddr_t)ep->e_start_hi << 32);
 1845 
 1846                         if (path.ep_bp != NULL) {
 1847                                 brelse(path.ep_bp);
 1848                                 path.ep_bp = NULL;
 1849                         }
 1850                         break;
 1851 
 1852                 case EXT4_EXT_CACHE_GAP:
 1853                         /* block has not been allocated yet */
 1854                         return (0);
 1855 
 1856                 case EXT4_EXT_CACHE_IN:
 1857                         newblk = lbn - nex.e_blk + (nex.e_start_lo |
 1858                             (daddr_t)nex.e_start_hi << 32);
 1859                         break;
 1860 
 1861                 default:
 1862                         panic("%s: invalid cache type", __func__);
 1863                 }
 1864 
 1865                 error = bread(ip->i_devvp, fsbtodb(fs, newblk), size, NOCRED, &bp);
 1866                 if (error) {
 1867                         brelse(bp);
 1868                         return (error);
 1869                 }
 1870 
 1871                 size -= bp->b_resid;
 1872                 if (size < xfersize) {
 1873                         if (size == 0) {
 1874                                 bqrelse(bp);
 1875                                 break;
 1876                         }
 1877                         xfersize = size;
 1878                 }
 1879                 error = uiomove(bp->b_data + blkoffset, (int)xfersize, uio);
 1880                 bqrelse(bp);
 1881                 if (error)
 1882                         return (error);
 1883         }
 1884 
 1885         return (0);
 1886 }
 1887 
 1888 /*
 1889  * Vnode op for writing.
 1890  */
 1891 static int
 1892 ext2_write(struct vop_write_args *ap)
 1893 {
 1894         struct vnode *vp;
 1895         struct uio *uio;
 1896         struct inode *ip;
 1897         struct m_ext2fs *fs;
 1898         struct buf *bp;
 1899         daddr_t lbn;
 1900         off_t osize;
 1901         int blkoffset, error, flags, ioflag, resid, size, seqcount, xfersize;
 1902 
 1903         ioflag = ap->a_ioflag;
 1904         uio = ap->a_uio;
 1905         vp = ap->a_vp;
 1906 
 1907         seqcount = ioflag >> IO_SEQSHIFT;
 1908         ip = VTOI(vp);
 1909 
 1910 #ifdef INVARIANTS
 1911         if (uio->uio_rw != UIO_WRITE)
 1912                 panic("%s: mode", "ext2_write");
 1913 #endif
 1914 
 1915         switch (vp->v_type) {
 1916         case VREG:
 1917                 if (ioflag & IO_APPEND)
 1918                         uio->uio_offset = ip->i_size;
 1919                 if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
 1920                         return (EPERM);
 1921                 /* FALLTHROUGH */
 1922         case VLNK:
 1923                 break;
 1924         case VDIR:
 1925                 /* XXX differs from ffs -- this is called from ext2_mkdir(). */
 1926                 if ((ioflag & IO_SYNC) == 0)
 1927                         panic("ext2_write: nonsync dir write");
 1928                 break;
 1929         default:
 1930                 panic("ext2_write: type %p %d (%jd,%jd)", (void *)vp,
 1931                     vp->v_type, (intmax_t)uio->uio_offset,
 1932                     (intmax_t)uio->uio_resid);
 1933         }
 1934 
 1935         KASSERT(uio->uio_resid >= 0, ("ext2_write: uio->uio_resid < 0"));
 1936         KASSERT(uio->uio_offset >= 0, ("ext2_write: uio->uio_offset < 0"));
 1937         fs = ip->i_e2fs;
 1938         if ((uoff_t)uio->uio_offset + uio->uio_resid > fs->e2fs_maxfilesize)
 1939                 return (EFBIG);
 1940         /*
 1941          * Maybe this should be above the vnode op call, but so long as
 1942          * file servers have no limits, I don't think it matters.
 1943          */
 1944         if (vn_rlimit_fsize(vp, uio, uio->uio_td))
 1945                 return (EFBIG);
 1946 
 1947         resid = uio->uio_resid;
 1948         osize = ip->i_size;
 1949         if (seqcount > BA_SEQMAX)
 1950                 flags = BA_SEQMAX << BA_SEQSHIFT;
 1951         else
 1952                 flags = seqcount << BA_SEQSHIFT;
 1953         if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
 1954                 flags |= IO_SYNC;
 1955 
 1956         for (error = 0; uio->uio_resid > 0;) {
 1957                 lbn = lblkno(fs, uio->uio_offset);
 1958                 blkoffset = blkoff(fs, uio->uio_offset);
 1959                 xfersize = fs->e2fs_fsize - blkoffset;
 1960                 if (uio->uio_resid < xfersize)
 1961                         xfersize = uio->uio_resid;
 1962                 if (uio->uio_offset + xfersize > ip->i_size)
 1963                         vnode_pager_setsize(vp, uio->uio_offset + xfersize);
 1964 
 1965                 /*
 1966                  * We must perform a read-before-write if the transfer size
 1967                  * does not cover the entire buffer.
 1968                  */
 1969                 if (fs->e2fs_bsize > xfersize)
 1970                         flags |= BA_CLRBUF;
 1971                 else
 1972                         flags &= ~BA_CLRBUF;
 1973                 error = ext2_balloc(ip, lbn, blkoffset + xfersize,
 1974                     ap->a_cred, &bp, flags);
 1975                 if (error != 0)
 1976                         break;
 1977 
 1978                 if ((ioflag & (IO_SYNC | IO_INVAL)) == (IO_SYNC | IO_INVAL))
 1979                         bp->b_flags |= B_NOCACHE;
 1980                 if (uio->uio_offset + xfersize > ip->i_size)
 1981                         ip->i_size = uio->uio_offset + xfersize;
 1982                 size = blksize(fs, ip, lbn) - bp->b_resid;
 1983                 if (size < xfersize)
 1984                         xfersize = size;
 1985 
 1986                 error =
 1987                     uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
 1988                 /*
 1989                  * If the buffer is not already filled and we encounter an
 1990                  * error while trying to fill it, we have to clear out any
 1991                  * garbage data from the pages instantiated for the buffer.
 1992                  * If we do not, a failed uiomove() during a write can leave
 1993                  * the prior contents of the pages exposed to a userland mmap.
 1994                  *
 1995                  * Note that we need only clear buffers with a transfer size
 1996                  * equal to the block size because buffers with a shorter
 1997                  * transfer size were cleared above by the call to ext2_balloc()
 1998                  * with the BA_CLRBUF flag set.
 1999                  *
 2000                  * If the source region for uiomove identically mmaps the
 2001                  * buffer, uiomove() performed the NOP copy, and the buffer
 2002                  * content remains valid because the page fault handler
 2003                  * validated the pages.
 2004                  */
 2005                 if (error != 0 && (bp->b_flags & B_CACHE) == 0 &&
 2006                     fs->e2fs_bsize == xfersize)
 2007                         vfs_bio_clrbuf(bp);
 2008                 if (ioflag & (IO_VMIO|IO_DIRECT)) {
 2009                         bp->b_flags |= B_RELBUF;
 2010                 }
 2011 
 2012                 /*
 2013                  * If IO_SYNC each buffer is written synchronously.  Otherwise
 2014                  * if we have a severe page deficiency write the buffer
 2015                  * asynchronously.  Otherwise try to cluster, and if that
 2016                  * doesn't do it then either do an async write (if O_DIRECT),
 2017                  * or a delayed write (if not).
 2018                  */
 2019                 if (ioflag & IO_SYNC) {
 2020                         (void)bwrite(bp);
 2021                 } else if (vm_page_count_severe() ||
 2022                             buf_dirty_count_severe() ||
 2023                     (ioflag & IO_ASYNC)) {
 2024                         bp->b_flags |= B_CLUSTEROK;
 2025                         bawrite(bp);
 2026                 } else if (xfersize + blkoffset == fs->e2fs_fsize) {
 2027                         if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
 2028                                 bp->b_flags |= B_CLUSTEROK;
 2029                                 cluster_write(vp, bp, ip->i_size, seqcount, 0);
 2030                         } else {
 2031                                 bawrite(bp);
 2032                         }
 2033                 } else if (ioflag & IO_DIRECT) {
 2034                         bp->b_flags |= B_CLUSTEROK;
 2035                         bawrite(bp);
 2036                 } else {
 2037                         bp->b_flags |= B_CLUSTEROK;
 2038                         bdwrite(bp);
 2039                 }
 2040                 if (error || xfersize == 0)
 2041                         break;
 2042         }
 2043         /*
 2044          * If we successfully wrote any data, and we are not the superuser
 2045          * we clear the setuid and setgid bits as a precaution against
 2046          * tampering.
 2047          */
 2048         if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid &&
 2049             ap->a_cred) {
 2050                 if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID, 0))
 2051                         ip->i_mode &= ~(ISUID | ISGID);
 2052         }
 2053         if (error) {
 2054                 if (ioflag & IO_UNIT) {
 2055                         (void)ext2_truncate(vp, osize,
 2056                             ioflag & IO_SYNC, ap->a_cred, uio->uio_td);
 2057                         uio->uio_offset -= resid - uio->uio_resid;
 2058                         uio->uio_resid = resid;
 2059                 }
 2060         }
 2061         if (uio->uio_resid != resid) {
 2062                 ip->i_flag |= IN_CHANGE | IN_UPDATE;
 2063                 if (ioflag & IO_SYNC)
 2064                         error = ext2_update(vp, 1);
 2065         }
 2066         return (error);
 2067 }
 2068 
 2069 /*
 2070  * get page routine
 2071  */
 2072 static int
 2073 ext2_getpages(struct vop_getpages_args *ap)
 2074 {
 2075         int i;
 2076         vm_page_t mreq;
 2077         int pcount;
 2078 
 2079         pcount = round_page(ap->a_count) / PAGE_SIZE;
 2080         mreq = ap->a_m[ap->a_reqpage];
 2081 
 2082         /*
 2083          * if ANY DEV_BSIZE blocks are valid on a large filesystem block,
 2084          * then the entire page is valid.  Since the page may be mapped,
 2085          * user programs might reference data beyond the actual end of file
 2086          * occuring within the page.  We have to zero that data.
 2087          */
 2088         VM_OBJECT_WLOCK(mreq->object);
 2089         if (mreq->valid) {
 2090                 if (mreq->valid != VM_PAGE_BITS_ALL)
 2091                         vm_page_zero_invalid(mreq, TRUE);
 2092                 for (i = 0; i < pcount; i++) {
 2093                         if (i != ap->a_reqpage) {
 2094                                 vm_page_lock(ap->a_m[i]);
 2095                                 vm_page_free(ap->a_m[i]);
 2096                                 vm_page_unlock(ap->a_m[i]);
 2097                         }
 2098                 }
 2099                 VM_OBJECT_WUNLOCK(mreq->object);
 2100                 return VM_PAGER_OK;
 2101         }
 2102         VM_OBJECT_WUNLOCK(mreq->object);
 2103 
 2104         return vnode_pager_generic_getpages(ap->a_vp, ap->a_m,
 2105                                             ap->a_count,
 2106                                             ap->a_reqpage);
 2107 }

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