The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/fs/ext2fs/ext2_vfsops.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) 1989, 1991, 1993, 1994
    9  *      The Regents of the University of California.  All rights reserved.
   10  *
   11  * Redistribution and use in source and binary forms, with or without
   12  * modification, are permitted provided that the following conditions
   13  * are met:
   14  * 1. Redistributions of source code must retain the above copyright
   15  *    notice, this list of conditions and the following disclaimer.
   16  * 2. Redistributions in binary form must reproduce the above copyright
   17  *    notice, this list of conditions and the following disclaimer in the
   18  *    documentation and/or other materials provided with the distribution.
   19  * 4. Neither the name of the University nor the names of its contributors
   20  *    may be used to endorse or promote products derived from this software
   21  *    without specific prior written permission.
   22  *
   23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   33  * SUCH DAMAGE.
   34  *
   35  *      @(#)ffs_vfsops.c        8.8 (Berkeley) 4/18/94
   36  * $FreeBSD: stable/11/sys/fs/ext2fs/ext2_vfsops.c 350385 2019-07-27 19:29:28Z fsu $
   37  */
   38 
   39 #include <sys/param.h>
   40 #include <sys/systm.h>
   41 #include <sys/namei.h>
   42 #include <sys/priv.h>
   43 #include <sys/proc.h>
   44 #include <sys/kernel.h>
   45 #include <sys/vnode.h>
   46 #include <sys/mount.h>
   47 #include <sys/bio.h>
   48 #include <sys/buf.h>
   49 #include <sys/conf.h>
   50 #include <sys/endian.h>
   51 #include <sys/fcntl.h>
   52 #include <sys/malloc.h>
   53 #include <sys/stat.h>
   54 #include <sys/mutex.h>
   55 
   56 #include <geom/geom.h>
   57 #include <geom/geom_vfs.h>
   58 
   59 #include <fs/ext2fs/ext2_mount.h>
   60 #include <fs/ext2fs/inode.h>
   61 
   62 #include <fs/ext2fs/fs.h>
   63 #include <fs/ext2fs/ext2fs.h>
   64 #include <fs/ext2fs/ext2_dinode.h>
   65 #include <fs/ext2fs/ext2_extern.h>
   66 
   67 static int      ext2_flushfiles(struct mount *mp, int flags, struct thread *td);
   68 static int      ext2_mountfs(struct vnode *, struct mount *);
   69 static int      ext2_reload(struct mount *mp, struct thread *td);
   70 static int      ext2_sbupdate(struct ext2mount *, int);
   71 static int      ext2_cgupdate(struct ext2mount *, int);
   72 static vfs_unmount_t            ext2_unmount;
   73 static vfs_root_t               ext2_root;
   74 static vfs_statfs_t             ext2_statfs;
   75 static vfs_sync_t               ext2_sync;
   76 static vfs_vget_t               ext2_vget;
   77 static vfs_fhtovp_t             ext2_fhtovp;
   78 static vfs_mount_t              ext2_mount;
   79 
   80 MALLOC_DEFINE(M_EXT2NODE, "ext2_node", "EXT2 vnode private part");
   81 static MALLOC_DEFINE(M_EXT2MNT, "ext2_mount", "EXT2 mount structure");
   82 
   83 static struct vfsops ext2fs_vfsops = {
   84         .vfs_fhtovp =           ext2_fhtovp,
   85         .vfs_mount =            ext2_mount,
   86         .vfs_root =             ext2_root,      /* root inode via vget */
   87         .vfs_statfs =           ext2_statfs,
   88         .vfs_sync =             ext2_sync,
   89         .vfs_unmount =          ext2_unmount,
   90         .vfs_vget =             ext2_vget,
   91 };
   92 
   93 VFS_SET(ext2fs_vfsops, ext2fs, 0);
   94 
   95 static int      ext2_check_sb_compat(struct ext2fs *es, struct cdev *dev,
   96                     int ronly);
   97 static int      compute_sb_data(struct vnode * devvp,
   98                     struct ext2fs * es, struct m_ext2fs * fs);
   99 
  100 static const char *ext2_opts[] = { "acls", "async", "noatime", "noclusterr", 
  101     "noclusterw", "noexec", "export", "force", "from", "multilabel",
  102     "suiddir", "nosymfollow", "sync", "union", NULL };
  103 
  104 /*
  105  * VFS Operations.
  106  *
  107  * mount system call
  108  */
  109 static int
  110 ext2_mount(struct mount *mp)
  111 {
  112         struct vfsoptlist *opts;
  113         struct vnode *devvp;
  114         struct thread *td;
  115         struct ext2mount *ump = NULL;
  116         struct m_ext2fs *fs;
  117         struct nameidata nd, *ndp = &nd;
  118         accmode_t accmode;
  119         char *path, *fspec;
  120         int error, flags, len;
  121 
  122         td = curthread;
  123         opts = mp->mnt_optnew;
  124 
  125         if (vfs_filteropt(opts, ext2_opts))
  126                 return (EINVAL);
  127 
  128         vfs_getopt(opts, "fspath", (void **)&path, NULL);
  129         /* Double-check the length of path.. */
  130         if (strlen(path) >= MAXMNTLEN)
  131                 return (ENAMETOOLONG);
  132 
  133         fspec = NULL;
  134         error = vfs_getopt(opts, "from", (void **)&fspec, &len);
  135         if (!error && fspec[len - 1] != '\0')
  136                 return (EINVAL);
  137 
  138         /*
  139          * If updating, check whether changing from read-only to
  140          * read/write; if there is no device name, that's all we do.
  141          */
  142         if (mp->mnt_flag & MNT_UPDATE) {
  143                 ump = VFSTOEXT2(mp);
  144                 fs = ump->um_e2fs;
  145                 error = 0;
  146                 if (fs->e2fs_ronly == 0 &&
  147                     vfs_flagopt(opts, "ro", NULL, 0)) {
  148                         error = VFS_SYNC(mp, MNT_WAIT);
  149                         if (error)
  150                                 return (error);
  151                         flags = WRITECLOSE;
  152                         if (mp->mnt_flag & MNT_FORCE)
  153                                 flags |= FORCECLOSE;
  154                         error = ext2_flushfiles(mp, flags, td);
  155                         if (error == 0 && fs->e2fs_wasvalid && ext2_cgupdate(ump, MNT_WAIT) == 0) {
  156                                 fs->e2fs->e2fs_state |= E2FS_ISCLEAN;
  157                                 ext2_sbupdate(ump, MNT_WAIT);
  158                         }
  159                         fs->e2fs_ronly = 1;
  160                         vfs_flagopt(opts, "ro", &mp->mnt_flag, MNT_RDONLY);
  161                         g_topology_lock();
  162                         g_access(ump->um_cp, 0, -1, 0);
  163                         g_topology_unlock();
  164                 }
  165                 if (!error && (mp->mnt_flag & MNT_RELOAD))
  166                         error = ext2_reload(mp, td);
  167                 if (error)
  168                         return (error);
  169                 devvp = ump->um_devvp;
  170                 if (fs->e2fs_ronly && !vfs_flagopt(opts, "ro", NULL, 0)) {
  171                         if (ext2_check_sb_compat(fs->e2fs, devvp->v_rdev, 0))
  172                                 return (EPERM);
  173 
  174                         /*
  175                          * If upgrade to read-write by non-root, then verify
  176                          * that user has necessary permissions on the device.
  177                          */
  178                         vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
  179                         error = VOP_ACCESS(devvp, VREAD | VWRITE,
  180                             td->td_ucred, td);
  181                         if (error)
  182                                 error = priv_check(td, PRIV_VFS_MOUNT_PERM);
  183                         if (error) {
  184                                 VOP_UNLOCK(devvp, 0);
  185                                 return (error);
  186                         }
  187                         VOP_UNLOCK(devvp, 0);
  188                         g_topology_lock();
  189                         error = g_access(ump->um_cp, 0, 1, 0);
  190                         g_topology_unlock();
  191                         if (error)
  192                                 return (error);
  193 
  194                         if ((fs->e2fs->e2fs_state & E2FS_ISCLEAN) == 0 ||
  195                             (fs->e2fs->e2fs_state & E2FS_ERRORS)) {
  196                                 if (mp->mnt_flag & MNT_FORCE) {
  197                                         printf(
  198 "WARNING: %s was not properly dismounted\n", fs->e2fs_fsmnt);
  199                                 } else {
  200                                         printf(
  201 "WARNING: R/W mount of %s denied.  Filesystem is not clean - run fsck\n",
  202                                             fs->e2fs_fsmnt);
  203                                         return (EPERM);
  204                                 }
  205                         }
  206                         fs->e2fs->e2fs_state &= ~E2FS_ISCLEAN;
  207                         (void)ext2_cgupdate(ump, MNT_WAIT);
  208                         fs->e2fs_ronly = 0;
  209                         MNT_ILOCK(mp);
  210                         mp->mnt_flag &= ~MNT_RDONLY;
  211                         MNT_IUNLOCK(mp);
  212                 }
  213                 if (vfs_flagopt(opts, "export", NULL, 0)) {
  214                         /* Process export requests in vfs_mount.c. */
  215                         return (error);
  216                 }
  217         }
  218 
  219         /*
  220          * Not an update, or updating the name: look up the name
  221          * and verify that it refers to a sensible disk device.
  222          */
  223         if (fspec == NULL)
  224                 return (EINVAL);
  225         NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspec, td);
  226         if ((error = namei(ndp)) != 0)
  227                 return (error);
  228         NDFREE(ndp, NDF_ONLY_PNBUF);
  229         devvp = ndp->ni_vp;
  230 
  231         if (!vn_isdisk(devvp, &error)) {
  232                 vput(devvp);
  233                 return (error);
  234         }
  235 
  236         /*
  237          * If mount by non-root, then verify that user has necessary
  238          * permissions on the device.
  239          *
  240          * XXXRW: VOP_ACCESS() enough?
  241          */
  242         accmode = VREAD;
  243         if ((mp->mnt_flag & MNT_RDONLY) == 0)
  244                 accmode |= VWRITE;
  245         error = VOP_ACCESS(devvp, accmode, td->td_ucred, td);
  246         if (error)
  247                 error = priv_check(td, PRIV_VFS_MOUNT_PERM);
  248         if (error) {
  249                 vput(devvp);
  250                 return (error);
  251         }
  252 
  253         if ((mp->mnt_flag & MNT_UPDATE) == 0) {
  254                 error = ext2_mountfs(devvp, mp);
  255         } else {
  256                 if (devvp != ump->um_devvp) {
  257                         vput(devvp);
  258                         return (EINVAL);        /* needs translation */
  259                 } else
  260                         vput(devvp);
  261         }
  262         if (error) {
  263                 vrele(devvp);
  264                 return (error);
  265         }
  266         ump = VFSTOEXT2(mp);
  267         fs = ump->um_e2fs;
  268 
  269         /*
  270          * Note that this strncpy() is ok because of a check at the start
  271          * of ext2_mount().
  272          */
  273         strncpy(fs->e2fs_fsmnt, path, MAXMNTLEN);
  274         fs->e2fs_fsmnt[MAXMNTLEN - 1] = '\0';
  275         vfs_mountedfrom(mp, fspec);
  276         return (0);
  277 }
  278 
  279 static int
  280 ext2_check_sb_compat(struct ext2fs *es, struct cdev *dev, int ronly)
  281 {
  282         uint32_t i, mask;
  283 
  284         if (es->e2fs_magic != E2FS_MAGIC) {
  285                 printf("ext2fs: %s: wrong magic number %#x (expected %#x)\n",
  286                     devtoname(dev), es->e2fs_magic, E2FS_MAGIC);
  287                 return (1);
  288         }
  289         if (es->e2fs_rev > E2FS_REV0) {
  290                 mask = es->e2fs_features_incompat & ~(EXT2F_INCOMPAT_SUPP |
  291                     EXT4F_RO_INCOMPAT_SUPP);
  292                 if (mask) {
  293                         printf("WARNING: mount of %s denied due to "
  294                             "unsupported optional features:\n", devtoname(dev));
  295                         for (i = 0;
  296                             i < sizeof(incompat)/sizeof(struct ext2_feature);
  297                             i++)
  298                                 if (mask & incompat[i].mask)
  299                                         printf("%s ", incompat[i].name);
  300                         printf("\n");
  301                         return (1);
  302                 }
  303                 mask = es->e2fs_features_rocompat & ~EXT2F_ROCOMPAT_SUPP;
  304                 if (!ronly && mask) {
  305                         printf("WARNING: R/W mount of %s denied due to "
  306                             "unsupported optional features:\n", devtoname(dev));
  307                         for (i = 0;
  308                             i < sizeof(ro_compat)/sizeof(struct ext2_feature);
  309                             i++)
  310                                 if (mask & ro_compat[i].mask)
  311                                         printf("%s ", ro_compat[i].name);
  312                         printf("\n");
  313                         return (1);
  314                 }
  315         }
  316         return (0);
  317 }
  318 
  319 /*
  320  * This computes the fields of the m_ext2fs structure from the
  321  * data in the ext2fs structure read in.
  322  */
  323 static int
  324 compute_sb_data(struct vnode *devvp, struct ext2fs *es,
  325     struct m_ext2fs *fs)
  326 {
  327         int db_count, error;
  328         int i;
  329         int logic_sb_block = 1; /* XXX for now */
  330         struct buf *bp;
  331         uint32_t e2fs_descpb;
  332 
  333         fs->e2fs_bshift = EXT2_MIN_BLOCK_LOG_SIZE + es->e2fs_log_bsize;
  334         fs->e2fs_bsize = 1U << fs->e2fs_bshift;
  335         fs->e2fs_fsbtodb = es->e2fs_log_bsize + 1;
  336         fs->e2fs_qbmask = fs->e2fs_bsize - 1;
  337         fs->e2fs_fsize = EXT2_MIN_FRAG_SIZE << es->e2fs_log_fsize;
  338         if (fs->e2fs_fsize)
  339                 fs->e2fs_fpb = fs->e2fs_bsize / fs->e2fs_fsize;
  340         fs->e2fs_bpg = es->e2fs_bpg;
  341         fs->e2fs_fpg = es->e2fs_fpg;
  342         fs->e2fs_ipg = es->e2fs_ipg;
  343         if (es->e2fs_rev == E2FS_REV0) {
  344                 fs->e2fs_isize = E2FS_REV0_INODE_SIZE;
  345         } else {
  346                 fs->e2fs_isize = es->e2fs_inode_size;
  347 
  348                 /*
  349                  * Simple sanity check for superblock inode size value.
  350                  */
  351                 if (EXT2_INODE_SIZE(fs) < E2FS_REV0_INODE_SIZE ||
  352                     EXT2_INODE_SIZE(fs) > fs->e2fs_bsize ||
  353                     (fs->e2fs_isize & (fs->e2fs_isize - 1)) != 0) {
  354                         printf("ext2fs: invalid inode size %d\n",
  355                             fs->e2fs_isize);
  356                         return (EIO);
  357                 }
  358         }
  359         /* Check for extra isize in big inodes. */
  360         if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_EXTRA_ISIZE) &&
  361             EXT2_INODE_SIZE(fs) < sizeof(struct ext2fs_dinode)) {
  362                 printf("ext2fs: no space for extra inode timestamps\n");
  363                 return (EINVAL);
  364         }
  365         /* Check for group descriptor size */
  366         if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_64BIT) &&
  367             (es->e3fs_desc_size != sizeof(struct ext2_gd))) {
  368                 printf("ext2fs: group descriptor size unsupported %d\n",
  369                     es->e3fs_desc_size);
  370                 return (EINVAL);
  371         }
  372         /* Check for block size = 1K|2K|4K */
  373         if (es->e2fs_log_bsize > 2) {
  374                 printf("ext2fs: bad block size: %d\n", es->e2fs_log_bsize);
  375                 return (EINVAL);
  376         }
  377         /* Check for group size */
  378         if (fs->e2fs_bpg == 0 || fs->e2fs_fpg == 0) {
  379                 printf("ext2fs: zero blocks/fragments per group");
  380                 return (EINVAL);
  381         } else if (fs->e2fs_bpg != fs->e2fs_fpg) {
  382                 printf("ext2fs: blocks per group not equal fragments per group");
  383                 return (EINVAL);
  384         }
  385         if (fs->e2fs_bpg != fs->e2fs_bsize * 8) {
  386                 printf("ext2fs: non-standard group size unsupported %d\n",
  387                     fs->e2fs_bpg);
  388                 return (EINVAL);
  389         }
  390 
  391         fs->e2fs_ipb = fs->e2fs_bsize / EXT2_INODE_SIZE(fs);
  392         if (fs->e2fs_ipg == 0) {
  393                 printf("ext2fs: zero inodes per group\n");
  394                 return (EINVAL);
  395         }
  396         fs->e2fs_itpg = fs->e2fs_ipg / fs->e2fs_ipb;
  397         /* s_resuid / s_resgid ? */
  398         fs->e2fs_gcount = howmany(es->e2fs_bcount - es->e2fs_first_dblock,
  399             EXT2_BLOCKS_PER_GROUP(fs));
  400         e2fs_descpb = fs->e2fs_bsize / sizeof(struct ext2_gd);
  401         db_count = howmany(fs->e2fs_gcount, e2fs_descpb);
  402         fs->e2fs_gdbcount = db_count;
  403         fs->e2fs_gd = malloc(db_count * fs->e2fs_bsize,
  404             M_EXT2MNT, M_WAITOK);
  405         fs->e2fs_contigdirs = malloc(fs->e2fs_gcount *
  406             sizeof(*fs->e2fs_contigdirs), M_EXT2MNT, M_WAITOK | M_ZERO);
  407 
  408         /*
  409          * Adjust logic_sb_block.
  410          * Godmar thinks: if the blocksize is greater than 1024, then
  411          * the superblock is logically part of block zero.
  412          */
  413         if (fs->e2fs_bsize > SBSIZE)
  414                 logic_sb_block = 0;
  415         for (i = 0; i < db_count; i++) {
  416                 error = bread(devvp,
  417                     fsbtodb(fs, logic_sb_block + i + 1),
  418                     fs->e2fs_bsize, NOCRED, &bp);
  419                 if (error) {
  420                         free(fs->e2fs_contigdirs, M_EXT2MNT);
  421                         free(fs->e2fs_gd, M_EXT2MNT);
  422                         brelse(bp);
  423                         return (error);
  424                 }
  425                 e2fs_cgload((struct ext2_gd *)bp->b_data,
  426                     &fs->e2fs_gd[
  427                     i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
  428                     fs->e2fs_bsize);
  429                 brelse(bp);
  430                 bp = NULL;
  431         }
  432         /* Verify cg csum */
  433         if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_GDT_CSUM)) {
  434                 error = ext2_gd_csum_verify(fs, devvp->v_rdev);
  435                 if (error)
  436                         return (error);
  437         }
  438         /* Initialization for the ext2 Orlov allocator variant. */
  439         fs->e2fs_total_dir = 0;
  440         for (i = 0; i < fs->e2fs_gcount; i++)
  441                 fs->e2fs_total_dir += fs->e2fs_gd[i].ext2bgd_ndirs;
  442 
  443         if (es->e2fs_rev == E2FS_REV0 ||
  444             !EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_LARGEFILE))
  445                 fs->e2fs_maxfilesize = 0x7fffffff;
  446         else {
  447                 fs->e2fs_maxfilesize = 0xffffffffffff;
  448                 if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_HUGE_FILE))
  449                         fs->e2fs_maxfilesize = 0x7fffffffffffffff;
  450         }
  451         if (es->e4fs_flags & E2FS_UNSIGNED_HASH) {
  452                 fs->e2fs_uhash = 3;
  453         } else if ((es->e4fs_flags & E2FS_SIGNED_HASH) == 0) {
  454 #ifdef __CHAR_UNSIGNED__
  455                 es->e4fs_flags |= E2FS_UNSIGNED_HASH;
  456                 fs->e2fs_uhash = 3;
  457 #else
  458                 es->e4fs_flags |= E2FS_SIGNED_HASH;
  459 #endif
  460         }
  461 
  462         return (0);
  463 }
  464 
  465 /*
  466  * Reload all incore data for a filesystem (used after running fsck on
  467  * the root filesystem and finding things to fix). The filesystem must
  468  * be mounted read-only.
  469  *
  470  * Things to do to update the mount:
  471  *      1) invalidate all cached meta-data.
  472  *      2) re-read superblock from disk.
  473  *      3) invalidate all cluster summary information.
  474  *      4) invalidate all inactive vnodes.
  475  *      5) invalidate all cached file data.
  476  *      6) re-read inode data for all active vnodes.
  477  * XXX we are missing some steps, in particular # 3, this has to be reviewed.
  478  */
  479 static int
  480 ext2_reload(struct mount *mp, struct thread *td)
  481 {
  482         struct vnode *vp, *mvp, *devvp;
  483         struct inode *ip;
  484         struct buf *bp;
  485         struct ext2fs *es;
  486         struct m_ext2fs *fs;
  487         struct csum *sump;
  488         int error, i;
  489         int32_t *lp;
  490 
  491         if ((mp->mnt_flag & MNT_RDONLY) == 0)
  492                 return (EINVAL);
  493         /*
  494          * Step 1: invalidate all cached meta-data.
  495          */
  496         devvp = VFSTOEXT2(mp)->um_devvp;
  497         vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
  498         if (vinvalbuf(devvp, 0, 0, 0) != 0)
  499                 panic("ext2_reload: dirty1");
  500         VOP_UNLOCK(devvp, 0);
  501 
  502         /*
  503          * Step 2: re-read superblock from disk.
  504          * constants have been adjusted for ext2
  505          */
  506         if ((error = bread(devvp, SBLOCK, SBSIZE, NOCRED, &bp)) != 0)
  507                 return (error);
  508         es = (struct ext2fs *)bp->b_data;
  509         if (ext2_check_sb_compat(es, devvp->v_rdev, 0) != 0) {
  510                 brelse(bp);
  511                 return (EIO);           /* XXX needs translation */
  512         }
  513         fs = VFSTOEXT2(mp)->um_e2fs;
  514         bcopy(bp->b_data, fs->e2fs, sizeof(struct ext2fs));
  515 
  516         if ((error = compute_sb_data(devvp, es, fs)) != 0) {
  517                 brelse(bp);
  518                 return (error);
  519         }
  520 #ifdef UNKLAR
  521         if (fs->fs_sbsize < SBSIZE)
  522                 bp->b_flags |= B_INVAL;
  523 #endif
  524         brelse(bp);
  525 
  526         /*
  527          * Step 3: invalidate all cluster summary information.
  528          */
  529         if (fs->e2fs_contigsumsize > 0) {
  530                 lp = fs->e2fs_maxcluster;
  531                 sump = fs->e2fs_clustersum;
  532                 for (i = 0; i < fs->e2fs_gcount; i++, sump++) {
  533                         *lp++ = fs->e2fs_contigsumsize;
  534                         sump->cs_init = 0;
  535                         bzero(sump->cs_sum, fs->e2fs_contigsumsize + 1);
  536                 }
  537         }
  538 
  539 loop:
  540         MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
  541                 /*
  542                  * Step 4: invalidate all cached file data.
  543                  */
  544                 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) {
  545                         MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
  546                         goto loop;
  547                 }
  548                 if (vinvalbuf(vp, 0, 0, 0))
  549                         panic("ext2_reload: dirty2");
  550 
  551                 /*
  552                  * Step 5: re-read inode data for all active vnodes.
  553                  */
  554                 ip = VTOI(vp);
  555                 error = bread(devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
  556                     (int)fs->e2fs_bsize, NOCRED, &bp);
  557                 if (error) {
  558                         VOP_UNLOCK(vp, 0);
  559                         vrele(vp);
  560                         MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
  561                         return (error);
  562                 }
  563                 ext2_ei2i((struct ext2fs_dinode *)((char *)bp->b_data +
  564                     EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number)), ip);
  565                 brelse(bp);
  566                 VOP_UNLOCK(vp, 0);
  567                 vrele(vp);
  568         }
  569         return (0);
  570 }
  571 
  572 /*
  573  * Common code for mount and mountroot.
  574  */
  575 static int
  576 ext2_mountfs(struct vnode *devvp, struct mount *mp)
  577 {
  578         struct ext2mount *ump;
  579         struct buf *bp;
  580         struct m_ext2fs *fs;
  581         struct ext2fs *es;
  582         struct cdev *dev = devvp->v_rdev;
  583         struct g_consumer *cp;
  584         struct bufobj *bo;
  585         struct csum *sump;
  586         int error;
  587         int ronly;
  588         int i;
  589         u_long size;
  590         int32_t *lp;
  591         int32_t e2fs_maxcontig;
  592 
  593         ronly = vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0);
  594         /* XXX: use VOP_ACESS to check FS perms */
  595         g_topology_lock();
  596         error = g_vfs_open(devvp, &cp, "ext2fs", ronly ? 0 : 1);
  597         g_topology_unlock();
  598         VOP_UNLOCK(devvp, 0);
  599         if (error)
  600                 return (error);
  601 
  602         /* XXX: should we check for some sectorsize or 512 instead? */
  603         if (((SBSIZE % cp->provider->sectorsize) != 0) ||
  604             (SBSIZE < cp->provider->sectorsize)) {
  605                 g_topology_lock();
  606                 g_vfs_close(cp);
  607                 g_topology_unlock();
  608                 return (EINVAL);
  609         }
  610 
  611         bo = &devvp->v_bufobj;
  612         bo->bo_private = cp;
  613         bo->bo_ops = g_vfs_bufops;
  614         if (devvp->v_rdev->si_iosize_max != 0)
  615                 mp->mnt_iosize_max = devvp->v_rdev->si_iosize_max;
  616         if (mp->mnt_iosize_max > MAXPHYS)
  617                 mp->mnt_iosize_max = MAXPHYS;
  618 
  619         bp = NULL;
  620         ump = NULL;
  621         if ((error = bread(devvp, SBLOCK, SBSIZE, NOCRED, &bp)) != 0)
  622                 goto out;
  623         es = (struct ext2fs *)bp->b_data;
  624         if (ext2_check_sb_compat(es, dev, ronly) != 0) {
  625                 error = EINVAL;         /* XXX needs translation */
  626                 goto out;
  627         }
  628         if ((es->e2fs_state & E2FS_ISCLEAN) == 0 ||
  629             (es->e2fs_state & E2FS_ERRORS)) {
  630                 if (ronly || (mp->mnt_flag & MNT_FORCE)) {
  631                         printf(
  632 "WARNING: Filesystem was not properly dismounted\n");
  633                 } else {
  634                         printf(
  635 "WARNING: R/W mount denied.  Filesystem is not clean - run fsck\n");
  636                         error = EPERM;
  637                         goto out;
  638                 }
  639         }
  640         ump = malloc(sizeof(*ump), M_EXT2MNT, M_WAITOK | M_ZERO);
  641 
  642         /*
  643          * I don't know whether this is the right strategy. Note that
  644          * we dynamically allocate both an m_ext2fs and an ext2fs
  645          * while Linux keeps the super block in a locked buffer.
  646          */
  647         ump->um_e2fs = malloc(sizeof(struct m_ext2fs),
  648             M_EXT2MNT, M_WAITOK | M_ZERO);
  649         ump->um_e2fs->e2fs = malloc(sizeof(struct ext2fs),
  650             M_EXT2MNT, M_WAITOK);
  651         mtx_init(EXT2_MTX(ump), "EXT2FS", "EXT2FS Lock", MTX_DEF);
  652         bcopy(es, ump->um_e2fs->e2fs, (u_int)sizeof(struct ext2fs));
  653         if ((error = compute_sb_data(devvp, ump->um_e2fs->e2fs, ump->um_e2fs)))
  654                 goto out;
  655 
  656         /*
  657          * Calculate the maximum contiguous blocks and size of cluster summary
  658          * array.  In FFS this is done by newfs; however, the superblock
  659          * in ext2fs doesn't have these variables, so we can calculate
  660          * them here.
  661          */
  662         e2fs_maxcontig = MAX(1, MAXPHYS / ump->um_e2fs->e2fs_bsize);
  663         ump->um_e2fs->e2fs_contigsumsize = MIN(e2fs_maxcontig, EXT2_MAXCONTIG);
  664         if (ump->um_e2fs->e2fs_contigsumsize > 0) {
  665                 size = ump->um_e2fs->e2fs_gcount * sizeof(int32_t);
  666                 ump->um_e2fs->e2fs_maxcluster = malloc(size, M_EXT2MNT, M_WAITOK);
  667                 size = ump->um_e2fs->e2fs_gcount * sizeof(struct csum);
  668                 ump->um_e2fs->e2fs_clustersum = malloc(size, M_EXT2MNT, M_WAITOK);
  669                 lp = ump->um_e2fs->e2fs_maxcluster;
  670                 sump = ump->um_e2fs->e2fs_clustersum;
  671                 for (i = 0; i < ump->um_e2fs->e2fs_gcount; i++, sump++) {
  672                         *lp++ = ump->um_e2fs->e2fs_contigsumsize;
  673                         sump->cs_init = 0;
  674                         sump->cs_sum = malloc((ump->um_e2fs->e2fs_contigsumsize + 1) *
  675                             sizeof(int32_t), M_EXT2MNT, M_WAITOK | M_ZERO);
  676                 }
  677         }
  678 
  679         brelse(bp);
  680         bp = NULL;
  681         fs = ump->um_e2fs;
  682         fs->e2fs_ronly = ronly; /* ronly is set according to mnt_flags */
  683 
  684         /*
  685          * If the fs is not mounted read-only, make sure the super block is
  686          * always written back on a sync().
  687          */
  688         fs->e2fs_wasvalid = fs->e2fs->e2fs_state & E2FS_ISCLEAN ? 1 : 0;
  689         if (ronly == 0) {
  690                 fs->e2fs_fmod = 1;      /* mark it modified */
  691                 fs->e2fs->e2fs_state &= ~E2FS_ISCLEAN;  /* set fs invalid */
  692         }
  693         mp->mnt_data = ump;
  694         mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
  695         mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
  696         mp->mnt_maxsymlinklen = EXT2_MAXSYMLINKLEN;
  697         MNT_ILOCK(mp);
  698         mp->mnt_flag |= MNT_LOCAL;
  699         MNT_IUNLOCK(mp);
  700         ump->um_mountp = mp;
  701         ump->um_dev = dev;
  702         ump->um_devvp = devvp;
  703         ump->um_bo = &devvp->v_bufobj;
  704         ump->um_cp = cp;
  705 
  706         /*
  707          * Setting those two parameters allowed us to use
  708          * ufs_bmap w/o changse!
  709          */
  710         ump->um_nindir = EXT2_ADDR_PER_BLOCK(fs);
  711         ump->um_bptrtodb = fs->e2fs->e2fs_log_bsize + 1;
  712         ump->um_seqinc = EXT2_FRAGS_PER_BLOCK(fs);
  713         if (ronly == 0)
  714                 ext2_sbupdate(ump, MNT_WAIT);
  715         /*
  716          * Initialize filesystem stat information in mount struct.
  717          */
  718         MNT_ILOCK(mp);
  719         mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED |
  720             MNTK_USES_BCACHE;
  721         MNT_IUNLOCK(mp);
  722         return (0);
  723 out:
  724         if (bp)
  725                 brelse(bp);
  726         if (cp != NULL) {
  727                 g_topology_lock();
  728                 g_vfs_close(cp);
  729                 g_topology_unlock();
  730         }
  731         if (ump) {
  732                 mtx_destroy(EXT2_MTX(ump));
  733                 free(ump->um_e2fs->e2fs_gd, M_EXT2MNT);
  734                 free(ump->um_e2fs->e2fs_contigdirs, M_EXT2MNT);
  735                 free(ump->um_e2fs->e2fs, M_EXT2MNT);
  736                 free(ump->um_e2fs, M_EXT2MNT);
  737                 free(ump, M_EXT2MNT);
  738                 mp->mnt_data = NULL;
  739         }
  740         return (error);
  741 }
  742 
  743 /*
  744  * Unmount system call.
  745  */
  746 static int
  747 ext2_unmount(struct mount *mp, int mntflags)
  748 {
  749         struct ext2mount *ump;
  750         struct m_ext2fs *fs;
  751         struct csum *sump;
  752         int error, flags, i, ronly;
  753 
  754         flags = 0;
  755         if (mntflags & MNT_FORCE) {
  756                 if (mp->mnt_flag & MNT_ROOTFS)
  757                         return (EINVAL);
  758                 flags |= FORCECLOSE;
  759         }
  760         if ((error = ext2_flushfiles(mp, flags, curthread)) != 0)
  761                 return (error);
  762         ump = VFSTOEXT2(mp);
  763         fs = ump->um_e2fs;
  764         ronly = fs->e2fs_ronly;
  765         if (ronly == 0 && ext2_cgupdate(ump, MNT_WAIT) == 0) {
  766                 if (fs->e2fs_wasvalid)
  767                         fs->e2fs->e2fs_state |= E2FS_ISCLEAN;
  768                 ext2_sbupdate(ump, MNT_WAIT);
  769         }
  770 
  771         g_topology_lock();
  772         g_vfs_close(ump->um_cp);
  773         g_topology_unlock();
  774         vrele(ump->um_devvp);
  775         sump = fs->e2fs_clustersum;
  776         for (i = 0; i < fs->e2fs_gcount; i++, sump++)
  777                 free(sump->cs_sum, M_EXT2MNT);
  778         free(fs->e2fs_clustersum, M_EXT2MNT);
  779         free(fs->e2fs_maxcluster, M_EXT2MNT);
  780         free(fs->e2fs_gd, M_EXT2MNT);
  781         free(fs->e2fs_contigdirs, M_EXT2MNT);
  782         free(fs->e2fs, M_EXT2MNT);
  783         free(fs, M_EXT2MNT);
  784         free(ump, M_EXT2MNT);
  785         mp->mnt_data = NULL;
  786         MNT_ILOCK(mp);
  787         mp->mnt_flag &= ~MNT_LOCAL;
  788         MNT_IUNLOCK(mp);
  789         return (error);
  790 }
  791 
  792 /*
  793  * Flush out all the files in a filesystem.
  794  */
  795 static int
  796 ext2_flushfiles(struct mount *mp, int flags, struct thread *td)
  797 {
  798         int error;
  799 
  800         error = vflush(mp, 0, flags, td);
  801         return (error);
  802 }
  803 
  804 /*
  805  * Get filesystem statistics.
  806  */
  807 int
  808 ext2_statfs(struct mount *mp, struct statfs *sbp)
  809 {
  810         struct ext2mount *ump;
  811         struct m_ext2fs *fs;
  812         uint32_t overhead, overhead_per_group, ngdb;
  813         int i, ngroups;
  814 
  815         ump = VFSTOEXT2(mp);
  816         fs = ump->um_e2fs;
  817         if (fs->e2fs->e2fs_magic != E2FS_MAGIC)
  818                 panic("ext2_statfs");
  819 
  820         /*
  821          * Compute the overhead (FS structures)
  822          */
  823         overhead_per_group =
  824             1 /* block bitmap */ +
  825             1 /* inode bitmap */ +
  826             fs->e2fs_itpg;
  827         overhead = fs->e2fs->e2fs_first_dblock +
  828             fs->e2fs_gcount * overhead_per_group;
  829         if (fs->e2fs->e2fs_rev > E2FS_REV0 &&
  830             fs->e2fs->e2fs_features_rocompat & EXT2F_ROCOMPAT_SPARSESUPER) {
  831                 for (i = 0, ngroups = 0; i < fs->e2fs_gcount; i++) {
  832                         if (ext2_cg_has_sb(fs, i))
  833                                 ngroups++;
  834                 }
  835         } else {
  836                 ngroups = fs->e2fs_gcount;
  837         }
  838         ngdb = fs->e2fs_gdbcount;
  839         if (fs->e2fs->e2fs_rev > E2FS_REV0 &&
  840             fs->e2fs->e2fs_features_compat & EXT2F_COMPAT_RESIZE)
  841                 ngdb += fs->e2fs->e2fs_reserved_ngdb;
  842         overhead += ngroups * (1 /* superblock */ + ngdb);
  843 
  844         sbp->f_bsize = EXT2_FRAG_SIZE(fs);
  845         sbp->f_iosize = EXT2_BLOCK_SIZE(fs);
  846         sbp->f_blocks = fs->e2fs->e2fs_bcount - overhead;
  847         sbp->f_bfree = fs->e2fs->e2fs_fbcount;
  848         sbp->f_bavail = sbp->f_bfree - fs->e2fs->e2fs_rbcount;
  849         sbp->f_files = fs->e2fs->e2fs_icount;
  850         sbp->f_ffree = fs->e2fs->e2fs_ficount;
  851         return (0);
  852 }
  853 
  854 /*
  855  * Go through the disk queues to initiate sandbagged IO;
  856  * go through the inodes to write those that have been modified;
  857  * initiate the writing of the super block if it has been modified.
  858  *
  859  * Note: we are always called with the filesystem marked `MPBUSY'.
  860  */
  861 static int
  862 ext2_sync(struct mount *mp, int waitfor)
  863 {
  864         struct vnode *mvp, *vp;
  865         struct thread *td;
  866         struct inode *ip;
  867         struct ext2mount *ump = VFSTOEXT2(mp);
  868         struct m_ext2fs *fs;
  869         int error, allerror = 0;
  870 
  871         td = curthread;
  872         fs = ump->um_e2fs;
  873         if (fs->e2fs_fmod != 0 && fs->e2fs_ronly != 0) {                /* XXX */
  874                 printf("fs = %s\n", fs->e2fs_fsmnt);
  875                 panic("ext2_sync: rofs mod");
  876         }
  877 
  878         /*
  879          * Write back each (modified) inode.
  880          */
  881 loop:
  882         MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
  883                 if (vp->v_type == VNON) {
  884                         VI_UNLOCK(vp);
  885                         continue;
  886                 }
  887                 ip = VTOI(vp);
  888                 if ((ip->i_flag &
  889                     (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0 &&
  890                     (vp->v_bufobj.bo_dirty.bv_cnt == 0 ||
  891                     waitfor == MNT_LAZY)) {
  892                         VI_UNLOCK(vp);
  893                         continue;
  894                 }
  895                 error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
  896                 if (error) {
  897                         if (error == ENOENT) {
  898                                 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
  899                                 goto loop;
  900                         }
  901                         continue;
  902                 }
  903                 if ((error = VOP_FSYNC(vp, waitfor, td)) != 0)
  904                         allerror = error;
  905                 VOP_UNLOCK(vp, 0);
  906                 vrele(vp);
  907         }
  908 
  909         /*
  910          * Force stale filesystem control information to be flushed.
  911          */
  912         if (waitfor != MNT_LAZY) {
  913                 vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
  914                 if ((error = VOP_FSYNC(ump->um_devvp, waitfor, td)) != 0)
  915                         allerror = error;
  916                 VOP_UNLOCK(ump->um_devvp, 0);
  917         }
  918 
  919         /*
  920          * Write back modified superblock.
  921          */
  922         if (fs->e2fs_fmod != 0) {
  923                 fs->e2fs_fmod = 0;
  924                 fs->e2fs->e2fs_wtime = time_second;
  925                 if ((error = ext2_cgupdate(ump, waitfor)) != 0)
  926                         allerror = error;
  927         }
  928         return (allerror);
  929 }
  930 
  931 /*
  932  * Look up an EXT2FS dinode number to find its incore vnode, otherwise read it
  933  * in from disk.  If it is in core, wait for the lock bit to clear, then
  934  * return the inode locked.  Detection and handling of mount points must be
  935  * done by the calling routine.
  936  */
  937 static int
  938 ext2_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp)
  939 {
  940         struct m_ext2fs *fs;
  941         struct inode *ip;
  942         struct ext2mount *ump;
  943         struct buf *bp;
  944         struct vnode *vp;
  945         struct thread *td;
  946         unsigned int i, used_blocks;
  947         int error;
  948 
  949         td = curthread;
  950         error = vfs_hash_get(mp, ino, flags, td, vpp, NULL, NULL);
  951         if (error || *vpp != NULL)
  952                 return (error);
  953 
  954         ump = VFSTOEXT2(mp);
  955         ip = malloc(sizeof(struct inode), M_EXT2NODE, M_WAITOK | M_ZERO);
  956 
  957         /* Allocate a new vnode/inode. */
  958         if ((error = getnewvnode("ext2fs", mp, &ext2_vnodeops, &vp)) != 0) {
  959                 *vpp = NULL;
  960                 free(ip, M_EXT2NODE);
  961                 return (error);
  962         }
  963         vp->v_data = ip;
  964         ip->i_vnode = vp;
  965         ip->i_e2fs = fs = ump->um_e2fs;
  966         ip->i_ump = ump;
  967         ip->i_number = ino;
  968 
  969         lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
  970         error = insmntque(vp, mp);
  971         if (error != 0) {
  972                 free(ip, M_EXT2NODE);
  973                 *vpp = NULL;
  974                 return (error);
  975         }
  976         error = vfs_hash_insert(vp, ino, flags, td, vpp, NULL, NULL);
  977         if (error || *vpp != NULL)
  978                 return (error);
  979 
  980         /* Read in the disk contents for the inode, copy into the inode. */
  981         if ((error = bread(ump->um_devvp, fsbtodb(fs, ino_to_fsba(fs, ino)),
  982             (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) {
  983                 /*
  984                  * The inode does not contain anything useful, so it would
  985                  * be misleading to leave it on its hash chain. With mode
  986                  * still zero, it will be unlinked and returned to the free
  987                  * list by vput().
  988                  */
  989                 brelse(bp);
  990                 vput(vp);
  991                 *vpp = NULL;
  992                 return (error);
  993         }
  994         /* convert ext2 inode to dinode */
  995         ext2_ei2i((struct ext2fs_dinode *)((char *)bp->b_data + EXT2_INODE_SIZE(fs) *
  996             ino_to_fsbo(fs, ino)), ip);
  997         ip->i_block_group = ino_to_cg(fs, ino);
  998         ip->i_next_alloc_block = 0;
  999         ip->i_next_alloc_goal = 0;
 1000 
 1001         /*
 1002          * Now we want to make sure that block pointers for unused
 1003          * blocks are zeroed out - ext2_balloc depends on this
 1004          * although for regular files and directories only
 1005          *
 1006          * If IN_E4EXTENTS is enabled, unused blocks are not zeroed
 1007          * out because we could corrupt the extent tree.
 1008          */
 1009         if (!(ip->i_flag & IN_E4EXTENTS) &&
 1010             (S_ISDIR(ip->i_mode) || S_ISREG(ip->i_mode))) {
 1011                 used_blocks = howmany(ip->i_size, fs->e2fs_bsize);
 1012                 for (i = used_blocks; i < EXT2_NDIR_BLOCKS; i++)
 1013                         ip->i_db[i] = 0;
 1014         }
 1015 #ifdef EXT2FS_DEBUG
 1016         ext2_print_inode(ip);
 1017 #endif
 1018         bqrelse(bp);
 1019 
 1020         /*
 1021          * Initialize the vnode from the inode, check for aliases.
 1022          * Note that the underlying vnode may have changed.
 1023          */
 1024         if ((error = ext2_vinit(mp, &ext2_fifoops, &vp)) != 0) {
 1025                 vput(vp);
 1026                 *vpp = NULL;
 1027                 return (error);
 1028         }
 1029 
 1030         /*
 1031          * Finish inode initialization.
 1032          */
 1033 
 1034         *vpp = vp;
 1035         return (0);
 1036 }
 1037 
 1038 /*
 1039  * File handle to vnode
 1040  *
 1041  * Have to be really careful about stale file handles:
 1042  * - check that the inode number is valid
 1043  * - call ext2_vget() to get the locked inode
 1044  * - check for an unallocated inode (i_mode == 0)
 1045  * - check that the given client host has export rights and return
 1046  *   those rights via. exflagsp and credanonp
 1047  */
 1048 static int
 1049 ext2_fhtovp(struct mount *mp, struct fid *fhp, int flags, struct vnode **vpp)
 1050 {
 1051         struct inode *ip;
 1052         struct ufid *ufhp;
 1053         struct vnode *nvp;
 1054         struct m_ext2fs *fs;
 1055         int error;
 1056 
 1057         ufhp = (struct ufid *)fhp;
 1058         fs = VFSTOEXT2(mp)->um_e2fs;
 1059         if (ufhp->ufid_ino < EXT2_ROOTINO ||
 1060             ufhp->ufid_ino > fs->e2fs_gcount * fs->e2fs->e2fs_ipg)
 1061                 return (ESTALE);
 1062 
 1063         error = VFS_VGET(mp, ufhp->ufid_ino, LK_EXCLUSIVE, &nvp);
 1064         if (error) {
 1065                 *vpp = NULLVP;
 1066                 return (error);
 1067         }
 1068         ip = VTOI(nvp);
 1069         if (ip->i_mode == 0 ||
 1070             ip->i_gen != ufhp->ufid_gen || ip->i_nlink <= 0) {
 1071                 vput(nvp);
 1072                 *vpp = NULLVP;
 1073                 return (ESTALE);
 1074         }
 1075         *vpp = nvp;
 1076         vnode_create_vobject(*vpp, 0, curthread);
 1077         return (0);
 1078 }
 1079 
 1080 /*
 1081  * Write a superblock and associated information back to disk.
 1082  */
 1083 static int
 1084 ext2_sbupdate(struct ext2mount *mp, int waitfor)
 1085 {
 1086         struct m_ext2fs *fs = mp->um_e2fs;
 1087         struct ext2fs *es = fs->e2fs;
 1088         struct buf *bp;
 1089         int error = 0;
 1090 
 1091         bp = getblk(mp->um_devvp, SBLOCK, SBSIZE, 0, 0, 0);
 1092         bcopy((caddr_t)es, bp->b_data, (u_int)sizeof(struct ext2fs));
 1093         if (waitfor == MNT_WAIT)
 1094                 error = bwrite(bp);
 1095         else
 1096                 bawrite(bp);
 1097 
 1098         /*
 1099          * The buffers for group descriptors, inode bitmaps and block bitmaps
 1100          * are not busy at this point and are (hopefully) written by the
 1101          * usual sync mechanism. No need to write them here.
 1102          */
 1103         return (error);
 1104 }
 1105 int
 1106 ext2_cgupdate(struct ext2mount *mp, int waitfor)
 1107 {
 1108         struct m_ext2fs *fs = mp->um_e2fs;
 1109         struct buf *bp;
 1110         int i, error = 0, allerror = 0;
 1111 
 1112         allerror = ext2_sbupdate(mp, waitfor);
 1113 
 1114         /* Update gd csums */
 1115         if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_GDT_CSUM))
 1116                 ext2_gd_csum_set(fs);
 1117 
 1118         for (i = 0; i < fs->e2fs_gdbcount; i++) {
 1119                 bp = getblk(mp->um_devvp, fsbtodb(fs,
 1120                     fs->e2fs->e2fs_first_dblock +
 1121                     1 /* superblock */ + i), fs->e2fs_bsize, 0, 0, 0);
 1122                 e2fs_cgsave(&fs->e2fs_gd[
 1123                     i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
 1124                     (struct ext2_gd *)bp->b_data, fs->e2fs_bsize);
 1125                 if (waitfor == MNT_WAIT)
 1126                         error = bwrite(bp);
 1127                 else
 1128                         bawrite(bp);
 1129         }
 1130 
 1131         if (!allerror && error)
 1132                 allerror = error;
 1133         return (allerror);
 1134 }
 1135 
 1136 /*
 1137  * Return the root of a filesystem.
 1138  */
 1139 static int
 1140 ext2_root(struct mount *mp, int flags, struct vnode **vpp)
 1141 {
 1142         struct vnode *nvp;
 1143         int error;
 1144 
 1145         error = VFS_VGET(mp, EXT2_ROOTINO, LK_EXCLUSIVE, &nvp);
 1146         if (error)
 1147                 return (error);
 1148         *vpp = nvp;
 1149         return (0);
 1150 }

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