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ffs_vfsops.c

/*-
 * Copyright (c) 1989, 1991, 1993, 1994
 *    The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *    @(#)ffs_vfsops.c  8.31 (Berkeley) 5/20/95
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/ufs/ffs/ffs_vfsops.c,v 1.329 2007/04/04 07:29:53 delphij Exp $");

#include "opt_mac.h"
#include "opt_quota.h"
#include "opt_ufs.h"
#include "opt_ffs.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/mutex.h>

#include <security/mac/mac_framework.h>

#include <ufs/ufs/extattr.h>
#include <ufs/ufs/gjournal.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufs_extern.h>

#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>

#include <vm/vm.h>
#include <vm/uma.h>
#include <vm/vm_page.h>

#include <geom/geom.h>
#include <geom/geom_vfs.h>

static uma_zone_t uma_inode, uma_ufs1, uma_ufs2;

static int  ffs_reload(struct mount *, struct thread *);
static int  ffs_mountfs(struct vnode *, struct mount *, struct thread *);
static void ffs_oldfscompat_read(struct fs *, struct ufsmount *,
                ufs2_daddr_t);
static void ffs_oldfscompat_write(struct fs *, struct ufsmount *);
static void ffs_ifree(struct ufsmount *ump, struct inode *ip);
static vfs_init_t ffs_init;
static vfs_uninit_t ffs_uninit;
static vfs_extattrctl_t ffs_extattrctl;
static vfs_cmount_t ffs_cmount;
static vfs_unmount_t ffs_unmount;
static vfs_mount_t ffs_mount;
static vfs_statfs_t ffs_statfs;
static vfs_fhtovp_t ffs_fhtovp;
static vfs_sync_t ffs_sync;

static struct vfsops ufs_vfsops = {
      .vfs_extattrctl = ffs_extattrctl,
      .vfs_fhtovp =           ffs_fhtovp,
      .vfs_init =       ffs_init,
      .vfs_mount =            ffs_mount,
      .vfs_cmount =           ffs_cmount,
      .vfs_quotactl =         ufs_quotactl,
      .vfs_root =       ufs_root,
      .vfs_statfs =           ffs_statfs,
      .vfs_sync =       ffs_sync,
      .vfs_uninit =           ffs_uninit,
      .vfs_unmount =          ffs_unmount,
      .vfs_vget =       ffs_vget,
};

VFS_SET(ufs_vfsops, ufs, 0);
MODULE_VERSION(ufs, 1);

static b_strategy_t ffs_geom_strategy;
static b_write_t ffs_bufwrite;

static struct buf_ops ffs_ops = {
      .bop_name = "FFS",
      .bop_write =      ffs_bufwrite,
      .bop_strategy =   ffs_geom_strategy,
      .bop_sync = bufsync,
#ifdef NO_FFS_SNAPSHOT
      .bop_bdflush =    bufbdflush,
#else
      .bop_bdflush =    ffs_bdflush,
#endif
};

static const char *ffs_opts[] = { "acls", "async", "atime", "clusterr",
    "clusterw", "exec", "export", "force", "from", "multilabel", 
    "snapshot", "suid", "suiddir", "symfollow", "sync",
    "union", NULL };

static int
ffs_mount(struct mount *mp, struct thread *td)
{
      struct vnode *devvp;
      struct ufsmount *ump = 0;
      struct fs *fs;
      int error, flags;
      u_int mntorflags, mntandnotflags;
      mode_t accessmode;
      struct nameidata ndp;
      char *fspec;

      if (vfs_filteropt(mp->mnt_optnew, ffs_opts))
            return (EINVAL);
      if (uma_inode == NULL) {
            uma_inode = uma_zcreate("FFS inode",
                sizeof(struct inode), NULL, NULL, NULL, NULL,
                UMA_ALIGN_PTR, 0);
            uma_ufs1 = uma_zcreate("FFS1 dinode",
                sizeof(struct ufs1_dinode), NULL, NULL, NULL, NULL,
                UMA_ALIGN_PTR, 0);
            uma_ufs2 = uma_zcreate("FFS2 dinode",
                sizeof(struct ufs2_dinode), NULL, NULL, NULL, NULL,
                UMA_ALIGN_PTR, 0);
      }

      fspec = vfs_getopts(mp->mnt_optnew, "from", &error);
      if (error)
            return (error);

      mntorflags = 0;
      mntandnotflags = 0;
      if (vfs_getopt(mp->mnt_optnew, "acls", NULL, NULL) == 0)
            mntorflags |= MNT_ACLS;

      if (vfs_getopt(mp->mnt_optnew, "async", NULL, NULL) == 0)
            mntorflags |= MNT_ASYNC;

      if (vfs_getopt(mp->mnt_optnew, "force", NULL, NULL) == 0)
            mntorflags |= MNT_FORCE;

      if (vfs_getopt(mp->mnt_optnew, "multilabel", NULL, NULL) == 0)
            mntorflags |= MNT_MULTILABEL;

      if (vfs_getopt(mp->mnt_optnew, "noasync", NULL, NULL) == 0)
            mntandnotflags |= MNT_ASYNC;

      if (vfs_getopt(mp->mnt_optnew, "noatime", NULL, NULL) == 0)
            mntorflags |= MNT_NOATIME;

      if (vfs_getopt(mp->mnt_optnew, "noclusterr", NULL, NULL) == 0)
            mntorflags |= MNT_NOCLUSTERR;

      if (vfs_getopt(mp->mnt_optnew, "noclusterw", NULL, NULL) == 0)
            mntorflags |= MNT_NOCLUSTERW;

      if (vfs_getopt(mp->mnt_optnew, "snapshot", NULL, NULL) == 0)
            mntorflags |= MNT_SNAPSHOT;

      MNT_ILOCK(mp);
      mp->mnt_flag = (mp->mnt_flag | mntorflags) & ~mntandnotflags;
      MNT_IUNLOCK(mp);
      /*
       * If updating, check whether changing from read-only to
       * read/write; if there is no device name, that's all we do.
       */
      if (mp->mnt_flag & MNT_UPDATE) {
            ump = VFSTOUFS(mp);
            fs = ump->um_fs;
            devvp = ump->um_devvp;
            if (fs->fs_ronly == 0 &&
                vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
                  if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0)
                        return (error);
                  /*
                   * Flush any dirty data.
                   */
                  if ((error = ffs_sync(mp, MNT_WAIT, td)) != 0) {
                        vn_finished_write(mp);
                        return (error);
                  }
                  /*
                   * Check for and optionally get rid of files open
                   * for writing.
                   */
                  flags = WRITECLOSE;
                  if (mp->mnt_flag & MNT_FORCE)
                        flags |= FORCECLOSE;
                  if (mp->mnt_flag & MNT_SOFTDEP) {
                        error = softdep_flushfiles(mp, flags, td);
                  } else {
                        error = ffs_flushfiles(mp, flags, td);
                  }
                  if (error) {
                        vn_finished_write(mp);
                        return (error);
                  }
                  if (fs->fs_pendingblocks != 0 ||
                      fs->fs_pendinginodes != 0) {
                        printf("%s: %s: blocks %jd files %d\n",
                            fs->fs_fsmnt, "update error",
                            (intmax_t)fs->fs_pendingblocks,
                            fs->fs_pendinginodes);
                        fs->fs_pendingblocks = 0;
                        fs->fs_pendinginodes = 0;
                  }
                  if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) == 0)
                        fs->fs_clean = 1;
                  if ((error = ffs_sbupdate(ump, MNT_WAIT, 0)) != 0) {
                        fs->fs_ronly = 0;
                        fs->fs_clean = 0;
                        vn_finished_write(mp);
                        return (error);
                  }
                  vn_finished_write(mp);
                  DROP_GIANT();
                  g_topology_lock();
                  g_access(ump->um_cp, 0, -1, 0);
                  g_topology_unlock();
                  PICKUP_GIANT();
                  fs->fs_ronly = 1;
                  MNT_ILOCK(mp);
                  mp->mnt_flag |= MNT_RDONLY;
                  MNT_IUNLOCK(mp);
            }
            if ((mp->mnt_flag & MNT_RELOAD) &&
                (error = ffs_reload(mp, td)) != 0)
                  return (error);
            if (fs->fs_ronly &&
                !vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
                  /*
                   * If upgrade to read-write by non-root, then verify
                   * that user has necessary permissions on the device.
                   */
                  vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
                  error = VOP_ACCESS(devvp, VREAD | VWRITE,
                      td->td_ucred, td);
                  if (error)
                        error = priv_check(td, PRIV_VFS_MOUNT_PERM);
                  if (error) {
                        VOP_UNLOCK(devvp, 0, td);
                        return (error);
                  }
                  VOP_UNLOCK(devvp, 0, td);
                  fs->fs_flags &= ~FS_UNCLEAN;
                  if (fs->fs_clean == 0) {
                        fs->fs_flags |= FS_UNCLEAN;
                        if ((mp->mnt_flag & MNT_FORCE) ||
                            ((fs->fs_flags & FS_NEEDSFSCK) == 0 &&
                             (fs->fs_flags & FS_DOSOFTDEP))) {
                              printf("WARNING: %s was not %s\n",
                                 fs->fs_fsmnt, "properly dismounted");
                        } else {
                              printf(
"WARNING: R/W mount of %s denied.  Filesystem is not clean - run fsck\n",
                                  fs->fs_fsmnt);
                              return (EPERM);
                        }
                  }
                  DROP_GIANT();
                  g_topology_lock();
                  /*
                   * If we're the root device, we may not have an E count
                   * yet, get it now.
                   */
                  if (ump->um_cp->ace == 0)
                        error = g_access(ump->um_cp, 0, 1, 1);
                  else
                        error = g_access(ump->um_cp, 0, 1, 0);
                  g_topology_unlock();
                  PICKUP_GIANT();
                  if (error)
                        return (error);
                  if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0)
                        return (error);
                  fs->fs_ronly = 0;
                  MNT_ILOCK(mp);
                  mp->mnt_flag &= ~MNT_RDONLY;
                  MNT_IUNLOCK(mp);
                  fs->fs_clean = 0;
                  if ((error = ffs_sbupdate(ump, MNT_WAIT, 0)) != 0) {
                        vn_finished_write(mp);
                        return (error);
                  }
                  /* check to see if we need to start softdep */
                  if ((fs->fs_flags & FS_DOSOFTDEP) &&
                      (error = softdep_mount(devvp, mp, fs, td->td_ucred))){
                        vn_finished_write(mp);
                        return (error);
                  }
                  if (fs->fs_snapinum[0] != 0)
                        ffs_snapshot_mount(mp);
                  vn_finished_write(mp);
            }
            /*
             * Soft updates is incompatible with "async",
             * so if we are doing softupdates stop the user
             * from setting the async flag in an update.
             * Softdep_mount() clears it in an initial mount 
             * or ro->rw remount.
             */
            if (mp->mnt_flag & MNT_SOFTDEP) {
                  /* XXX: Reset too late ? */
                  MNT_ILOCK(mp);
                  mp->mnt_flag &= ~MNT_ASYNC;
                  MNT_IUNLOCK(mp);
            }
            /*
             * Keep MNT_ACLS flag if it is stored in superblock.
             */
            if ((fs->fs_flags & FS_ACLS) != 0) {
                  /* XXX: Set too late ? */
                  MNT_ILOCK(mp);
                  mp->mnt_flag |= MNT_ACLS;
                  MNT_IUNLOCK(mp);
            }

            /*
             * If this is a snapshot request, take the snapshot.
             */
            if (mp->mnt_flag & MNT_SNAPSHOT)
                  return (ffs_snapshot(mp, fspec));
      }

      /*
       * Not an update, or updating the name: look up the name
       * and verify that it refers to a sensible disk device.
       */
      NDINIT(&ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspec, td);
      if ((error = namei(&ndp)) != 0)
            return (error);
      NDFREE(&ndp, NDF_ONLY_PNBUF);
      devvp = ndp.ni_vp;
      if (!vn_isdisk(devvp, &error)) {
            vput(devvp);
            return (error);
      }

      /*
       * If mount by non-root, then verify that user has necessary
       * permissions on the device.
       */
      accessmode = VREAD;
      if ((mp->mnt_flag & MNT_RDONLY) == 0)
            accessmode |= VWRITE;
      error = VOP_ACCESS(devvp, accessmode, td->td_ucred, td);
      if (error)
            error = priv_check(td, PRIV_VFS_MOUNT_PERM);
      if (error) {
            vput(devvp);
            return (error);
      }

      if (mp->mnt_flag & MNT_UPDATE) {
            /*
             * Update only
             *
             * If it's not the same vnode, or at least the same device
             * then it's not correct.
             */

            if (devvp->v_rdev != ump->um_devvp->v_rdev)
                  error = EINVAL;   /* needs translation */
            vput(devvp);
            if (error)
                  return (error);
      } else {
            /*
             * New mount
             *
             * We need the name for the mount point (also used for
             * "last mounted on") copied in. If an error occurs,
             * the mount point is discarded by the upper level code.
             * Note that vfs_mount() populates f_mntonname for us.
             */
            if ((error = ffs_mountfs(devvp, mp, td)) != 0) {
                  vrele(devvp);
                  return (error);
            }
      }
      vfs_mountedfrom(mp, fspec);
      return (0);
}

/*
 * Compatibility with old mount system call.
 */

static int
ffs_cmount(struct mntarg *ma, void *data, int flags, struct thread *td)
{
      struct ufs_args args;
      int error;

      if (data == NULL)
            return (EINVAL);
      error = copyin(data, &args, sizeof args);
      if (error)
            return (error);

      ma = mount_argsu(ma, "from", args.fspec, MAXPATHLEN);
      ma = mount_arg(ma, "export", &args.export, sizeof args.export);
      error = kernel_mount(ma, flags);

      return (error);
}

/*
 * Reload all incore data for a filesystem (used after running fsck on
 * the root filesystem and finding things to fix). The filesystem must
 * be mounted read-only.
 *
 * Things to do to update the mount:
 *    1) invalidate all cached meta-data.
 *    2) re-read superblock from disk.
 *    3) re-read summary information from disk.
 *    4) invalidate all inactive vnodes.
 *    5) invalidate all cached file data.
 *    6) re-read inode data for all active vnodes.
 */
static int
ffs_reload(struct mount *mp, struct thread *td)
{
      struct vnode *vp, *mvp, *devvp;
      struct inode *ip;
      void *space;
      struct buf *bp;
      struct fs *fs, *newfs;
      struct ufsmount *ump;
      ufs2_daddr_t sblockloc;
      int i, blks, size, error;
      int32_t *lp;

      if ((mp->mnt_flag & MNT_RDONLY) == 0)
            return (EINVAL);
      ump = VFSTOUFS(mp);
      /*
       * Step 1: invalidate all cached meta-data.
       */
      devvp = VFSTOUFS(mp)->um_devvp;
      vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
      if (vinvalbuf(devvp, 0, td, 0, 0) != 0)
            panic("ffs_reload: dirty1");
      VOP_UNLOCK(devvp, 0, td);

      /*
       * Step 2: re-read superblock from disk.
       */
      fs = VFSTOUFS(mp)->um_fs;
      if ((error = bread(devvp, btodb(fs->fs_sblockloc), fs->fs_sbsize,
          NOCRED, &bp)) != 0)
            return (error);
      newfs = (struct fs *)bp->b_data;
      if ((newfs->fs_magic != FS_UFS1_MAGIC &&
           newfs->fs_magic != FS_UFS2_MAGIC) ||
          newfs->fs_bsize > MAXBSIZE ||
          newfs->fs_bsize < sizeof(struct fs)) {
                  brelse(bp);
                  return (EIO);           /* XXX needs translation */
      }
      /*
       * Copy pointer fields back into superblock before copying in     XXX
       * new superblock. These should really be in the ufsmount.  XXX
       * Note that important parameters (eg fs_ncg) are unchanged.
       */
      newfs->fs_csp = fs->fs_csp;
      newfs->fs_maxcluster = fs->fs_maxcluster;
      newfs->fs_contigdirs = fs->fs_contigdirs;
      newfs->fs_active = fs->fs_active;
      /* The file system is still read-only. */
      newfs->fs_ronly = 1;
      sblockloc = fs->fs_sblockloc;
      bcopy(newfs, fs, (u_int)fs->fs_sbsize);
      brelse(bp);
      mp->mnt_maxsymlinklen = fs->fs_maxsymlinklen;
      ffs_oldfscompat_read(fs, VFSTOUFS(mp), sblockloc);
      UFS_LOCK(ump);
      if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
            printf("%s: reload pending error: blocks %jd files %d\n",
                fs->fs_fsmnt, (intmax_t)fs->fs_pendingblocks,
                fs->fs_pendinginodes);
            fs->fs_pendingblocks = 0;
            fs->fs_pendinginodes = 0;
      }
      UFS_UNLOCK(ump);

      /*
       * Step 3: re-read summary information from disk.
       */
      blks = howmany(fs->fs_cssize, fs->fs_fsize);
      space = fs->fs_csp;
      for (i = 0; i < blks; i += fs->fs_frag) {
            size = fs->fs_bsize;
            if (i + fs->fs_frag > blks)
                  size = (blks - i) * fs->fs_fsize;
            error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + i), size,
                NOCRED, &bp);
            if (error)
                  return (error);
            bcopy(bp->b_data, space, (u_int)size);
            space = (char *)space + size;
            brelse(bp);
      }
      /*
       * We no longer know anything about clusters per cylinder group.
       */
      if (fs->fs_contigsumsize > 0) {
            lp = fs->fs_maxcluster;
            for (i = 0; i < fs->fs_ncg; i++)
                  *lp++ = fs->fs_contigsumsize;
      }

loop:
      MNT_ILOCK(mp);
      MNT_VNODE_FOREACH(vp, mp, mvp) {
            VI_LOCK(vp);
            if (vp->v_iflag & VI_DOOMED) {
                  VI_UNLOCK(vp);
                  continue;
            }
            MNT_IUNLOCK(mp);
            /*
             * Step 4: invalidate all cached file data.
             */
            if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) {
                  MNT_VNODE_FOREACH_ABORT(mp, mvp);
                  goto loop;
            }
            if (vinvalbuf(vp, 0, td, 0, 0))
                  panic("ffs_reload: dirty2");
            /*
             * Step 5: re-read inode data for all active vnodes.
             */
            ip = VTOI(vp);
            error =
                bread(devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
                (int)fs->fs_bsize, NOCRED, &bp);
            if (error) {
                  VOP_UNLOCK(vp, 0, td);
                  vrele(vp);
                  MNT_VNODE_FOREACH_ABORT(mp, mvp);
                  return (error);
            }
            ffs_load_inode(bp, ip, fs, ip->i_number);
            ip->i_effnlink = ip->i_nlink;
            brelse(bp);
            VOP_UNLOCK(vp, 0, td);
            vrele(vp);
            MNT_ILOCK(mp);
      }
      MNT_IUNLOCK(mp);
      return (0);
}

/*
 * Possible superblock locations ordered from most to least likely.
 */
static int sblock_try[] = SBLOCKSEARCH;

/*
 * Common code for mount and mountroot
 */
static int
ffs_mountfs(devvp, mp, td)
      struct vnode *devvp;
      struct mount *mp;
      struct thread *td;
{
      struct ufsmount *ump;
      struct buf *bp;
      struct fs *fs;
      struct cdev *dev;
      void *space;
      ufs2_daddr_t sblockloc;
      int error, i, blks, size, ronly;
      int32_t *lp;
      struct ucred *cred;
      struct g_consumer *cp;
      struct mount *nmp;

      dev = devvp->v_rdev;
      cred = td ? td->td_ucred : NOCRED;

      ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
      DROP_GIANT();
      g_topology_lock();
      error = g_vfs_open(devvp, &cp, "ffs", ronly ? 0 : 1);

      /*
       * If we are a root mount, drop the E flag so fsck can do its magic.
       * We will pick it up again when we remount R/W.
       */
      if (error == 0 && ronly && (mp->mnt_flag & MNT_ROOTFS))
            error = g_access(cp, 0, 0, -1);
      g_topology_unlock();
      PICKUP_GIANT();
      VOP_UNLOCK(devvp, 0, td);
      if (error)
            return (error);
      if (devvp->v_rdev->si_iosize_max != 0)
            mp->mnt_iosize_max = devvp->v_rdev->si_iosize_max;
      if (mp->mnt_iosize_max > MAXPHYS)
            mp->mnt_iosize_max = MAXPHYS;

      devvp->v_bufobj.bo_private = cp;
      devvp->v_bufobj.bo_ops = &ffs_ops;

      bp = NULL;
      ump = NULL;
      fs = NULL;
      sblockloc = 0;
      /*
       * Try reading the superblock in each of its possible locations.
       */
      for (i = 0; sblock_try[i] != -1; i++) {
            if ((SBLOCKSIZE % cp->provider->sectorsize) != 0) {
                  error = EINVAL;
                  vfs_mount_error(mp,
                      "Invalid sectorsize %d for superblock size %d",
                      cp->provider->sectorsize, SBLOCKSIZE);
                  goto out;
            }
            if ((error = bread(devvp, btodb(sblock_try[i]), SBLOCKSIZE,
                cred, &bp)) != 0)
                  goto out;
            fs = (struct fs *)bp->b_data;
            sblockloc = sblock_try[i];
            if ((fs->fs_magic == FS_UFS1_MAGIC ||
                 (fs->fs_magic == FS_UFS2_MAGIC &&
                  (fs->fs_sblockloc == sblockloc ||
                   (fs->fs_old_flags & FS_FLAGS_UPDATED) == 0))) &&
                fs->fs_bsize <= MAXBSIZE &&
                fs->fs_bsize >= sizeof(struct fs))
                  break;
            brelse(bp);
            bp = NULL;
      }
      if (sblock_try[i] == -1) {
            error = EINVAL;         /* XXX needs translation */
            goto out;
      }
      fs->fs_fmod = 0;
      fs->fs_flags &= ~FS_INDEXDIRS;      /* no support for directory indicies */
      fs->fs_flags &= ~FS_UNCLEAN;
      if (fs->fs_clean == 0) {
            fs->fs_flags |= FS_UNCLEAN;
            if (ronly || (mp->mnt_flag & MNT_FORCE) ||
                ((fs->fs_flags & FS_NEEDSFSCK) == 0 &&
                 (fs->fs_flags & FS_DOSOFTDEP))) {
                  printf(
"WARNING: %s was not properly dismounted\n",
                      fs->fs_fsmnt);
            } else {
                  printf(
"WARNING: R/W mount of %s denied.  Filesystem is not clean - run fsck\n",
                      fs->fs_fsmnt);
                  error = EPERM;
                  goto out;
            }
            if ((fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) &&
                (mp->mnt_flag & MNT_FORCE)) {
                  printf("%s: lost blocks %jd files %d\n", fs->fs_fsmnt,
                      (intmax_t)fs->fs_pendingblocks,
                      fs->fs_pendinginodes);
                  fs->fs_pendingblocks = 0;
                  fs->fs_pendinginodes = 0;
            }
      }
      if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
            printf("%s: mount pending error: blocks %jd files %d\n",
                fs->fs_fsmnt, (intmax_t)fs->fs_pendingblocks,
                fs->fs_pendinginodes);
            fs->fs_pendingblocks = 0;
            fs->fs_pendinginodes = 0;
      }
      if ((fs->fs_flags & FS_GJOURNAL) != 0) {
#ifdef UFS_GJOURNAL
            /*
             * Get journal provider name.
             */
            size = 1024;
            mp->mnt_gjprovider = malloc(size, M_UFSMNT, M_WAITOK);
            if (g_io_getattr("GJOURNAL::provider", cp, &size,
                mp->mnt_gjprovider) == 0) {
                  mp->mnt_gjprovider = realloc(mp->mnt_gjprovider, size,
                      M_UFSMNT, M_WAITOK);
                  MNT_ILOCK(mp);
                  mp->mnt_flag |= MNT_GJOURNAL;
                  MNT_IUNLOCK(mp);
            } else {
                  printf(
"WARNING: %s: GJOURNAL flag on fs but no gjournal provider below\n",
                      mp->mnt_stat.f_mntonname);
                  free(mp->mnt_gjprovider, M_UFSMNT);
                  mp->mnt_gjprovider = NULL;
            }
#else
            printf(
"WARNING: %s: GJOURNAL flag on fs but no UFS_GJOURNAL support\n",
                mp->mnt_stat.f_mntonname);
#endif
      } else {
            mp->mnt_gjprovider = NULL;
      }
      ump = malloc(sizeof *ump, M_UFSMNT, M_WAITOK | M_ZERO);
      ump->um_cp = cp;
      ump->um_bo = &devvp->v_bufobj;
      ump->um_fs = malloc((u_long)fs->fs_sbsize, M_UFSMNT, M_WAITOK);
      if (fs->fs_magic == FS_UFS1_MAGIC) {
            ump->um_fstype = UFS1;
            ump->um_balloc = ffs_balloc_ufs1;
      } else {
            ump->um_fstype = UFS2;
            ump->um_balloc = ffs_balloc_ufs2;
      }
      ump->um_blkatoff = ffs_blkatoff;
      ump->um_truncate = ffs_truncate;
      ump->um_update = ffs_update;
      ump->um_valloc = ffs_valloc;
      ump->um_vfree = ffs_vfree;
      ump->um_ifree = ffs_ifree;
      mtx_init(UFS_MTX(ump), "FFS", "FFS Lock", MTX_DEF);
      bcopy(bp->b_data, ump->um_fs, (u_int)fs->fs_sbsize);
      if (fs->fs_sbsize < SBLOCKSIZE)
            bp->b_flags |= B_INVAL | B_NOCACHE;
      brelse(bp);
      bp = NULL;
      fs = ump->um_fs;
      ffs_oldfscompat_read(fs, ump, sblockloc);
      fs->fs_ronly = ronly;
      size = fs->fs_cssize;
      blks = howmany(size, fs->fs_fsize);
      if (fs->fs_contigsumsize > 0)
            size += fs->fs_ncg * sizeof(int32_t);
      size += fs->fs_ncg * sizeof(u_int8_t);
      space = malloc((u_long)size, M_UFSMNT, M_WAITOK);
      fs->fs_csp = space;
      for (i = 0; i < blks; i += fs->fs_frag) {
            size = fs->fs_bsize;
            if (i + fs->fs_frag > blks)
                  size = (blks - i) * fs->fs_fsize;
            if ((error = bread(devvp, fsbtodb(fs, fs->fs_csaddr + i), size,
                cred, &bp)) != 0) {
                  free(fs->fs_csp, M_UFSMNT);
                  goto out;
            }
            bcopy(bp->b_data, space, (u_int)size);
            space = (char *)space + size;
            brelse(bp);
            bp = NULL;
      }
      if (fs->fs_contigsumsize > 0) {
            fs->fs_maxcluster = lp = space;
            for (i = 0; i < fs->fs_ncg; i++)
                  *lp++ = fs->fs_contigsumsize;
            space = lp;
      }
      size = fs->fs_ncg * sizeof(u_int8_t);
      fs->fs_contigdirs = (u_int8_t *)space;
      bzero(fs->fs_contigdirs, size);
      fs->fs_active = NULL;
      mp->mnt_data = (qaddr_t)ump;
      mp->mnt_stat.f_fsid.val[0] = fs->fs_id[0];
      mp->mnt_stat.f_fsid.val[1] = fs->fs_id[1];
      nmp = NULL;
      if (fs->fs_id[0] == 0 || fs->fs_id[1] == 0 || 
          (nmp = vfs_getvfs(&mp->mnt_stat.f_fsid))) {
            if (nmp)
                  vfs_rel(nmp);
            vfs_getnewfsid(mp);
      }
      mp->mnt_maxsymlinklen = fs->fs_maxsymlinklen;
      MNT_ILOCK(mp);
      mp->mnt_flag |= MNT_LOCAL;
      MNT_IUNLOCK(mp);
      if ((fs->fs_flags & FS_MULTILABEL) != 0) {
#ifdef MAC
            MNT_ILOCK(mp);
            mp->mnt_flag |= MNT_MULTILABEL;
            MNT_IUNLOCK(mp);
#else
            printf(
"WARNING: %s: multilabel flag on fs but no MAC support\n",
                mp->mnt_stat.f_mntonname);
#endif
      }
      if ((fs->fs_flags & FS_ACLS) != 0) {
#ifdef UFS_ACL
            MNT_ILOCK(mp);
            mp->mnt_flag |= MNT_ACLS;
            MNT_IUNLOCK(mp);
#else
            printf(
"WARNING: %s: ACLs flag on fs but no ACLs support\n",
                mp->mnt_stat.f_mntonname);
#endif
      }
      ump->um_mountp = mp;
      ump->um_dev = dev;
      ump->um_devvp = devvp;
      ump->um_nindir = fs->fs_nindir;
      ump->um_bptrtodb = fs->fs_fsbtodb;
      ump->um_seqinc = fs->fs_frag;
      for (i = 0; i < MAXQUOTAS; i++)
            ump->um_quotas[i] = NULLVP;
#ifdef UFS_EXTATTR
      ufs_extattr_uepm_init(&ump->um_extattr);
#endif
      /*
       * Set FS local "last mounted on" information (NULL pad)
       */
      bzero(fs->fs_fsmnt, MAXMNTLEN);
      strlcpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname, MAXMNTLEN);

      if( mp->mnt_flag & MNT_ROOTFS) {
            /*
             * Root mount; update timestamp in mount structure.
             * this will be used by the common root mount code
             * to update the system clock.
             */
            mp->mnt_time = fs->fs_time;
      }

      if (ronly == 0) {
            if ((fs->fs_flags & FS_DOSOFTDEP) &&
                (error = softdep_mount(devvp, mp, fs, cred)) != 0) {
                  free(fs->fs_csp, M_UFSMNT);
                  goto out;
            }
            if (fs->fs_snapinum[0] != 0)
                  ffs_snapshot_mount(mp);
            fs->fs_fmod = 1;
            fs->fs_clean = 0;
            (void) ffs_sbupdate(ump, MNT_WAIT, 0);
      }
      /*
       * Initialize filesystem stat information in mount struct.
       */
#ifdef UFS_EXTATTR
#ifdef UFS_EXTATTR_AUTOSTART
      /*
       *
       * Auto-starting does the following:
       *    - check for /.attribute in the fs, and extattr_start if so
       *    - for each file in .attribute, enable that file with
       *      an attribute of the same name.
       * Not clear how to report errors -- probably eat them.
       * This would all happen while the filesystem was busy/not
       * available, so would effectively be "atomic".
       */
      (void) ufs_extattr_autostart(mp, td);
#endif /* !UFS_EXTATTR_AUTOSTART */
#endif /* !UFS_EXTATTR */
      MNT_ILOCK(mp);
      mp->mnt_kern_flag |= MNTK_MPSAFE;
      MNT_IUNLOCK(mp);
      return (0);
out:
      if (bp)
            brelse(bp);
      if (cp != NULL) {
            DROP_GIANT();
            g_topology_lock();
            g_vfs_close(cp, td);
            g_topology_unlock();
            PICKUP_GIANT();
      }
      if (ump) {
            mtx_destroy(UFS_MTX(ump));
            if (mp->mnt_gjprovider != NULL) {
                  free(mp->mnt_gjprovider, M_UFSMNT);
                  mp->mnt_gjprovider = NULL;
            }
            free(ump->um_fs, M_UFSMNT);
            free(ump, M_UFSMNT);
            mp->mnt_data = (qaddr_t)0;
      }
      return (error);
}

#include <sys/sysctl.h>
static int bigcgs = 0;
SYSCTL_INT(_debug, OID_AUTO, bigcgs, CTLFLAG_RW, &bigcgs, 0, "");

/*
 * Sanity checks for loading old filesystem superblocks.
 * See ffs_oldfscompat_write below for unwound actions.
 *
 * XXX - Parts get retired eventually.
 * Unfortunately new bits get added.
 */
static void
ffs_oldfscompat_read(fs, ump, sblockloc)
      struct fs *fs;
      struct ufsmount *ump;
      ufs2_daddr_t sblockloc;
{
      off_t maxfilesize;

      /*
       * If not yet done, update fs_flags location and value of fs_sblockloc.
       */
      if ((fs->fs_old_flags & FS_FLAGS_UPDATED) == 0) {
            fs->fs_flags = fs->fs_old_flags;
            fs->fs_old_flags |= FS_FLAGS_UPDATED;
            fs->fs_sblockloc = sblockloc;
      }
      /*
       * If not yet done, update UFS1 superblock with new wider fields.
       */
      if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_maxbsize != fs->fs_bsize) {
            fs->fs_maxbsize = fs->fs_bsize;
            fs->fs_time = fs->fs_old_time;
            fs->fs_size = fs->fs_old_size;
            fs->fs_dsize = fs->fs_old_dsize;
            fs->fs_csaddr = fs->fs_old_csaddr;
            fs->fs_cstotal.cs_ndir = fs->fs_old_cstotal.cs_ndir;
            fs->fs_cstotal.cs_nbfree = fs->fs_old_cstotal.cs_nbfree;
            fs->fs_cstotal.cs_nifree = fs->fs_old_cstotal.cs_nifree;
            fs->fs_cstotal.cs_nffree = fs->fs_old_cstotal.cs_nffree;
      }
      if (fs->fs_magic == FS_UFS1_MAGIC &&
          fs->fs_old_inodefmt < FS_44INODEFMT) {
            fs->fs_maxfilesize = ((uint64_t)1 << 31) - 1;
            fs->fs_qbmask = ~fs->fs_bmask;
            fs->fs_qfmask = ~fs->fs_fmask;
      }
      if (fs->fs_magic == FS_UFS1_MAGIC) {
            ump->um_savedmaxfilesize = fs->fs_maxfilesize;
            maxfilesize = (uint64_t)0x80000000 * fs->fs_bsize - 1;
            if (fs->fs_maxfilesize > maxfilesize)
                  fs->fs_maxfilesize = maxfilesize;
      }
      /* Compatibility for old filesystems */
      if (fs->fs_avgfilesize <= 0)
            fs->fs_avgfilesize = AVFILESIZ;
      if (fs->fs_avgfpdir <= 0)
            fs->fs_avgfpdir = AFPDIR;
      if (bigcgs) {
            fs->fs_save_cgsize = fs->fs_cgsize;
            fs->fs_cgsize = fs->fs_bsize;
      }
}

/*
 * Unwinding superblock updates for old filesystems.
 * See ffs_oldfscompat_read above for details.
 *
 * XXX - Parts get retired eventually.
 * Unfortunately new bits get added.
 */
static void
ffs_oldfscompat_write(fs, ump)
      struct fs *fs;
      struct ufsmount *ump;
{

      /*
       * Copy back UFS2 updated fields that UFS1 inspects.
       */
      if (fs->fs_magic == FS_UFS1_MAGIC) {
            fs->fs_old_time = fs->fs_time;
            fs->fs_old_cstotal.cs_ndir = fs->fs_cstotal.cs_ndir;
            fs->fs_old_cstotal.cs_nbfree = fs->fs_cstotal.cs_nbfree;
            fs->fs_old_cstotal.cs_nifree = fs->fs_cstotal.cs_nifree;
            fs->fs_old_cstotal.cs_nffree = fs->fs_cstotal.cs_nffree;
            fs->fs_maxfilesize = ump->um_savedmaxfilesize;
      }
      if (bigcgs) {
            fs->fs_cgsize = fs->fs_save_cgsize;
            fs->fs_save_cgsize = 0;
      }
}

/*
 * unmount system call
 */
static int
ffs_unmount(mp, mntflags, td)
      struct mount *mp;
      int mntflags;
      struct thread *td;
{
      struct ufsmount *ump = VFSTOUFS(mp);
      struct fs *fs;
      int error, flags;

      flags = 0;
      if (mntflags & MNT_FORCE) {
            flags |= FORCECLOSE;
      }
#ifdef UFS_EXTATTR
      if ((error = ufs_extattr_stop(mp, td))) {
            if (error != EOPNOTSUPP)
                  printf("ffs_unmount: ufs_extattr_stop returned %d\n",
                      error);
      } else {
            ufs_extattr_uepm_destroy(&ump->um_extattr);
      }
#endif
      if (mp->mnt_flag & MNT_SOFTDEP) {
            if ((error = softdep_flushfiles(mp, flags, td)) != 0)
                  return (error);
      } else {
            if ((error = ffs_flushfiles(mp, flags, td)) != 0)
                  return (error);
      }
      fs = ump->um_fs;
      UFS_LOCK(ump);
      if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
            printf("%s: unmount pending error: blocks %jd files %d\n",
                fs->fs_fsmnt, (intmax_t)fs->fs_pendingblocks,
                fs->fs_pendinginodes);
            fs->fs_pendingblocks = 0;
            fs->fs_pendinginodes = 0;
      }
      UFS_UNLOCK(ump);
      if (fs->fs_ronly == 0) {
            fs->fs_clean = fs->fs_flags & (FS_UNCLEAN|FS_NEEDSFSCK) ? 0 : 1;
            error = ffs_sbupdate(ump, MNT_WAIT, 0);
            if (error) {
                  fs->fs_clean = 0;
                  return (error);
            }
      }
      DROP_GIANT();
      g_topology_lock();
      g_vfs_close(ump->um_cp, td);
      g_topology_unlock();
      PICKUP_GIANT();
      vrele(ump->um_devvp);
      mtx_destroy(UFS_MTX(ump));
      if (mp->mnt_gjprovider != NULL) {
            free(mp->mnt_gjprovider, M_UFSMNT);
            mp->mnt_gjprovider = NULL;
      }
      free(fs->fs_csp, M_UFSMNT);
      free(fs, M_UFSMNT);
      free(ump, M_UFSMNT);
      mp->mnt_data = (qaddr_t)0;
      MNT_ILOCK(mp);
      mp->mnt_flag &= ~MNT_LOCAL;
      MNT_IUNLOCK(mp);
      return (error);
}

/*
 * Flush out all the files in a filesystem.
 */
int
ffs_flushfiles(mp, flags, td)
      struct mount *mp;
      int flags;
      struct thread *td;
{
      struct ufsmount *ump;
      int error;

      ump = VFSTOUFS(mp);
#ifdef QUOTA
      if (mp->mnt_flag & MNT_QUOTA) {
            int i;
            error = vflush(mp, 0, SKIPSYSTEM|flags, td);
            if (error)
                  return (error);
            for (i = 0; i < MAXQUOTAS; i++) {
                  quotaoff(td, mp, i);
            }
            /*
             * Here we fall through to vflush again to ensure
             * that we have gotten rid of all the system vnodes.
             */
      }
#endif
      ASSERT_VOP_LOCKED(ump->um_devvp, "ffs_flushfiles");
      if (ump->um_devvp->v_vflag & VV_COPYONWRITE) {
            if ((error = vflush(mp, 0, SKIPSYSTEM | flags, td)) != 0)
                  return (error);
            ffs_snapshot_unmount(mp);
            flags |= FORCECLOSE;
            /*
             * Here we fall through to vflush again to ensure
             * that we have gotten rid of all the system vnodes.
             */
      }
        /*
       * Flush all the files.
       */
      if ((error = vflush(mp, 0, flags, td)) != 0)
            return (error);
      /*
       * Flush filesystem metadata.
       */
      vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY, td);
      error = VOP_FSYNC(ump->um_devvp, MNT_WAIT, td);
      VOP_UNLOCK(ump->um_devvp, 0, td);
      return (error);
}

/*
 * Get filesystem statistics.
 */
static int
ffs_statfs(mp, sbp, td)
      struct mount *mp;
      struct statfs *sbp;
      struct thread *td;
{
      struct ufsmount *ump;
      struct fs *fs;

      ump = VFSTOUFS(mp);
      fs = ump->um_fs;
      if (fs->fs_magic != FS_UFS1_MAGIC && fs->fs_magic != FS_UFS2_MAGIC)
            panic("ffs_statfs");
      sbp->f_version = STATFS_VERSION;
      sbp->f_bsize = fs->fs_fsize;
      sbp->f_iosize = fs->fs_bsize;
      sbp->f_blocks = fs->fs_dsize;
      UFS_LOCK(ump);
      sbp->f_bfree = fs->fs_cstotal.cs_nbfree * fs->fs_frag +
          fs->fs_cstotal.cs_nffree + dbtofsb(fs, fs->fs_pendingblocks);
      sbp->f_bavail = freespace(fs, fs->fs_minfree) +
          dbtofsb(fs, fs->fs_pendingblocks);
      sbp->f_files =  fs->fs_ncg * fs->fs_ipg - ROOTINO;
      sbp->f_ffree = fs->fs_cstotal.cs_nifree + fs->fs_pendinginodes;
      UFS_UNLOCK(ump);
      sbp->f_namemax = NAME_MAX;
      return (0);
}

/*
 * Go through the disk queues to initiate sandbagged IO;
 * go through the inodes to write those that have been modified;
 * initiate the writing of the super block if it has been modified.
 *
 * Note: we are always called with the filesystem marked `MPBUSY'.
 */
static int
ffs_sync(mp, waitfor, td)
      struct mount *mp;
      int waitfor;
      struct thread *td;
{
      struct vnode *mvp, *vp, *devvp;
      struct inode *ip;
      struct ufsmount *ump = VFSTOUFS(mp);
      struct fs *fs;
      int error, count, wait, lockreq, allerror = 0;
      int suspend;
      int suspended;
      int secondary_writes;
      int secondary_accwrites;
      int softdep_deps;
      int softdep_accdeps;
      struct bufobj *bo;

      fs = ump->um_fs;
      if (fs->fs_fmod != 0 && fs->fs_ronly != 0) {          /* XXX */
            printf("fs = %s\n", fs->fs_fsmnt);
            panic("ffs_sync: rofs mod");
      }
      /*
       * Write back each (modified) inode.
       */
      wait = 0;
      suspend = 0;
      suspended = 0;
      lockreq = LK_EXCLUSIVE | LK_NOWAIT;
      if (waitfor == MNT_SUSPEND) {
            suspend = 1;
            waitfor = MNT_WAIT;
      }
      if (waitfor == MNT_WAIT) {
            wait = 1;
            lockreq = LK_EXCLUSIVE;
      }
      lockreq |= LK_INTERLOCK | LK_SLEEPFAIL;
      MNT_ILOCK(mp);
loop:
      /* Grab snapshot of secondary write counts */
      secondary_writes = mp->mnt_secondary_writes;
      secondary_accwrites = mp->mnt_secondary_accwrites;

      /* Grab snapshot of softdep dependency counts */
      MNT_IUNLOCK(mp);
      softdep_get_depcounts(mp, &softdep_deps, &softdep_accdeps);
      MNT_ILOCK(mp);

      MNT_VNODE_FOREACH(vp, mp, mvp) {
            /*
             * Depend on the mntvnode_slock to keep things stable enough
             * for a quick test.  Since there might be hundreds of
             * thousands of vnodes, we cannot afford even a subroutine
             * call unless there's a good chance that we have work to do.
             */
            VI_LOCK(vp);
            if (vp->v_iflag & VI_DOOMED) {
                  VI_UNLOCK(vp);
                  continue;
            }
            ip = VTOI(vp);
            if (vp->v_type == VNON || ((ip->i_flag &
                (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0 &&
                vp->v_bufobj.bo_dirty.bv_cnt == 0)) {
                  VI_UNLOCK(vp);
                  continue;
            }
            MNT_IUNLOCK(mp);
            if ((error = vget(vp, lockreq, td)) != 0) {
                  MNT_ILOCK(mp);
                  if (error == ENOENT || error == ENOLCK) {
                        MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
                        goto loop;
                  }
                  continue;
            }
            if ((error = ffs_syncvnode(vp, waitfor)) != 0)
                  allerror = error;
            vput(vp);
            MNT_ILOCK(mp);
      }
      MNT_IUNLOCK(mp);
      /*
       * Force stale filesystem control information to be flushed.
       */
      if (waitfor == MNT_WAIT) {
            if ((error = softdep_flushworklist(ump->um_mountp, &count, td)))
                  allerror = error;
            /* Flushed work items may create new vnodes to clean */
            if (allerror == 0 && count) {
                  MNT_ILOCK(mp);
                  goto loop;
            }
      }
#ifdef QUOTA
      qsync(mp);
#endif
      devvp = ump->um_devvp;
      VI_LOCK(devvp);
      bo = &devvp->v_bufobj;
      if (waitfor != MNT_LAZY &&
          (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)) {
            vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, td);
            if ((error = VOP_FSYNC(devvp, waitfor, td)) != 0)
                  allerror = error;
            VOP_UNLOCK(devvp, 0, td);
            if (allerror == 0 && waitfor == MNT_WAIT) {
                  MNT_ILOCK(mp);
                  goto loop;
            }
      } else if (suspend != 0) {
            if (softdep_check_suspend(mp,
                                devvp,
                                softdep_deps,
                                softdep_accdeps,
                                secondary_writes,
                                secondary_accwrites) != 0)
                  goto loop;  /* More work needed */
            mtx_assert(MNT_MTX(mp), MA_OWNED);
            mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED;
            MNT_IUNLOCK(mp);
            suspended = 1;
      } else
            VI_UNLOCK(devvp);
      /*
       * Write back modified superblock.
       */
      if (fs->fs_fmod != 0 &&
          (error = ffs_sbupdate(ump, waitfor, suspended)) != 0)
            allerror = error;
      return (allerror);
}

int
ffs_vget(mp, ino, flags, vpp)
      struct mount *mp;
      ino_t ino;
      int flags;
      struct vnode **vpp;
{
      struct fs *fs;
      struct inode *ip;
      struct ufsmount *ump;
      struct buf *bp;
      struct vnode *vp;
      struct cdev *dev;
      int error;
      struct thread *td;

      error = vfs_hash_get(mp, ino, flags, curthread, vpp, NULL, NULL);
      if (error || *vpp != NULL)
            return (error);

      /*
       * We must promote to an exclusive lock for vnode creation.  This
       * can happen if lookup is passed LOCKSHARED.
       */
      if ((flags & LK_TYPE_MASK) == LK_SHARED) {
            flags &= ~LK_TYPE_MASK;
            flags |= LK_EXCLUSIVE;
      }

      /*
       * We do not lock vnode creation as it is believed to be too
       * expensive for such rare case as simultaneous creation of vnode
       * for same ino by different processes. We just allow them to race
       * and check later to decide who wins. Let the race begin!
       */

      ump = VFSTOUFS(mp);
      dev = ump->um_dev;
      fs = ump->um_fs;

      /*
       * If this MALLOC() is performed after the getnewvnode()
       * it might block, leaving a vnode with a NULL v_data to be
       * found by ffs_sync() if a sync happens to fire right then,
       * which will cause a panic because ffs_sync() blindly
       * dereferences vp->v_data (as well it should).
       */
      ip = uma_zalloc(uma_inode, M_WAITOK | M_ZERO);

      /* Allocate a new vnode/inode. */
      if (fs->fs_magic == FS_UFS1_MAGIC)
            error = getnewvnode("ufs", mp, &ffs_vnodeops1, &vp);
      else
            error = getnewvnode("ufs", mp, &ffs_vnodeops2, &vp);
      if (error) {
            *vpp = NULL;
            uma_zfree(uma_inode, ip);
            return (error);
      }
      /*
       * FFS supports recursive and shared locking.
       */
      vp->v_vnlock->lk_flags |= LK_CANRECURSE;
      vp->v_vnlock->lk_flags &= ~LK_NOSHARE;
      vp->v_data = ip;
      vp->v_bufobj.bo_bsize = fs->fs_bsize;
      ip->i_vnode = vp;
      ip->i_ump = ump;
      ip->i_fs = fs;
      ip->i_dev = dev;
      ip->i_number = ino;
#ifdef QUOTA
      {
            int i;
            for (i = 0; i < MAXQUOTAS; i++)
                  ip->i_dquot[i] = NODQUOT;
      }
#endif

      td = curthread;
      lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL, td);
      error = insmntque(vp, mp);
      if (error != 0) {
            uma_zfree(uma_inode, ip);
            *vpp = NULL;
            return (error);
      }
      error = vfs_hash_insert(vp, ino, flags, td, vpp, NULL, NULL);
      if (error || *vpp != NULL)
            return (error);

      /* Read in the disk contents for the inode, copy into the inode. */
      error = bread(ump->um_devvp, fsbtodb(fs, ino_to_fsba(fs, ino)),
          (int)fs->fs_bsize, NOCRED, &bp);
      if (error) {
            /*
             * The inode does not contain anything useful, so it would
             * be misleading to leave it on its hash chain. With mode
             * still zero, it will be unlinked and returned to the free
             * list by vput().
             */
            brelse(bp);
            vput(vp);
            *vpp = NULL;
            return (error);
      }
      if (ip->i_ump->um_fstype == UFS1)
            ip->i_din1 = uma_zalloc(uma_ufs1, M_WAITOK);
      else
            ip->i_din2 = uma_zalloc(uma_ufs2, M_WAITOK);
      ffs_load_inode(bp, ip, fs, ino);
      if (DOINGSOFTDEP(vp))
            softdep_load_inodeblock(ip);
      else
            ip->i_effnlink = ip->i_nlink;
      bqrelse(bp);

      /*
       * Initialize the vnode from the inode, check for aliases.
       * Note that the underlying vnode may have changed.
       */
      if (ip->i_ump->um_fstype == UFS1)
            error = ufs_vinit(mp, &ffs_fifoops1, &vp);
      else
            error = ufs_vinit(mp, &ffs_fifoops2, &vp);
      if (error) {
            vput(vp);
            *vpp = NULL;
            return (error);
      }

      /*
       * Finish inode initialization.
       */

      /*
       * Set up a generation number for this inode if it does not
       * already have one. This should only happen on old filesystems.
       */
      if (ip->i_gen == 0) {
            ip->i_gen = arc4random() / 2 + 1;
            if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
                  ip->i_flag |= IN_MODIFIED;
                  DIP_SET(ip, i_gen, ip->i_gen);
            }
      }
      /*
       * Ensure that uid and gid are correct. This is a temporary
       * fix until fsck has been changed to do the update.
       */
      if (fs->fs_magic == FS_UFS1_MAGIC &&            /* XXX */
          fs->fs_old_inodefmt < FS_44INODEFMT) {      /* XXX */
            ip->i_uid = ip->i_din1->di_ouid;    /* XXX */
            ip->i_gid = ip->i_din1->di_ogid;    /* XXX */
      }                                   /* XXX */

#ifdef MAC
      if ((mp->mnt_flag & MNT_MULTILABEL) && ip->i_mode) {
            /*
             * If this vnode is already allocated, and we're running
             * multi-label, attempt to perform a label association
             * from the extended attributes on the inode.
             */
            error = mac_associate_vnode_extattr(mp, vp);
            if (error) {
                  /* ufs_inactive will release ip->i_devvp ref. */
                  vput(vp);
                  *vpp = NULL;
                  return (error);
            }
      }
#endif

      *vpp = vp;
      return (0);
}

/*
 * File handle to vnode
 *
 * Have to be really careful about stale file handles:
 * - check that the inode number is valid
 * - call ffs_vget() to get the locked inode
 * - check for an unallocated inode (i_mode == 0)
 * - check that the given client host has export rights and return
 *   those rights via. exflagsp and credanonp
 */
static int
ffs_fhtovp(mp, fhp, vpp)
      struct mount *mp;
      struct fid *fhp;
      struct vnode **vpp;
{
      struct ufid *ufhp;
      struct fs *fs;

      ufhp = (struct ufid *)fhp;
      fs = VFSTOUFS(mp)->um_fs;
      if (ufhp->ufid_ino < ROOTINO ||
          ufhp->ufid_ino >= fs->fs_ncg * fs->fs_ipg)
            return (ESTALE);
      return (ufs_fhtovp(mp, ufhp, vpp));
}

/*
 * Initialize the filesystem.
 */
static int
ffs_init(vfsp)
      struct vfsconf *vfsp;
{

      softdep_initialize();
      return (ufs_init(vfsp));
}

/*
 * Undo the work of ffs_init().
 */
static int
ffs_uninit(vfsp)
      struct vfsconf *vfsp;
{
      int ret;

      ret = ufs_uninit(vfsp);
      softdep_uninitialize();
      return (ret);
}

/*
 * Write a superblock and associated information back to disk.
 */
int
ffs_sbupdate(mp, waitfor, suspended)
      struct ufsmount *mp;
      int waitfor;
      int suspended;
{
      struct fs *fs = mp->um_fs;
      struct buf *sbbp;
      struct buf *bp;
      int blks;
      void *space;
      int i, size, error, allerror = 0;

      if (fs->fs_ronly == 1 &&
          (mp->um_mountp->mnt_flag & (MNT_RDONLY | MNT_UPDATE)) != 
          (MNT_RDONLY | MNT_UPDATE))
            panic("ffs_sbupdate: write read-only filesystem");
      /*
       * We use the superblock's buf to serialize calls to ffs_sbupdate().
       */
      sbbp = getblk(mp->um_devvp, btodb(fs->fs_sblockloc), (int)fs->fs_sbsize,
          0, 0, 0);
      /*
       * First write back the summary information.
       */
      blks = howmany(fs->fs_cssize, fs->fs_fsize);
      space = fs->fs_csp;
      for (i = 0; i < blks; i += fs->fs_frag) {
            size = fs->fs_bsize;
            if (i + fs->fs_frag > blks)
                  size = (blks - i) * fs->fs_fsize;
            bp = getblk(mp->um_devvp, fsbtodb(fs, fs->fs_csaddr + i),
                size, 0, 0, 0);
            bcopy(space, bp->b_data, (u_int)size);
            space = (char *)space + size;
            if (suspended)
                  bp->b_flags |= B_VALIDSUSPWRT;
            if (waitfor != MNT_WAIT)
                  bawrite(bp);
            else if ((error = bwrite(bp)) != 0)
                  allerror = error;
      }
      /*
       * Now write back the superblock itself. If any errors occurred
       * up to this point, then fail so that the superblock avoids
       * being written out as clean.
       */
      if (allerror) {
            brelse(sbbp);
            return (allerror);
      }
      bp = sbbp;
      if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_sblockloc != SBLOCK_UFS1 &&
          (fs->fs_flags & FS_FLAGS_UPDATED) == 0) {
            printf("%s: correcting fs_sblockloc from %jd to %d\n",
                fs->fs_fsmnt, fs->fs_sblockloc, SBLOCK_UFS1);
            fs->fs_sblockloc = SBLOCK_UFS1;
      }
      if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_sblockloc != SBLOCK_UFS2 &&
          (fs->fs_flags & FS_FLAGS_UPDATED) == 0) {
            printf("%s: correcting fs_sblockloc from %jd to %d\n",
                fs->fs_fsmnt, fs->fs_sblockloc, SBLOCK_UFS2);
            fs->fs_sblockloc = SBLOCK_UFS2;
      }
      fs->fs_fmod = 0;
      fs->fs_time = time_second;
      bcopy((caddr_t)fs, bp->b_data, (u_int)fs->fs_sbsize);
      ffs_oldfscompat_write((struct fs *)bp->b_data, mp);
      if (suspended)
            bp->b_flags |= B_VALIDSUSPWRT;
      if (waitfor != MNT_WAIT)
            bawrite(bp);
      else if ((error = bwrite(bp)) != 0)
            allerror = error;
      return (allerror);
}

static int
ffs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp,
      int attrnamespace, const char *attrname, struct thread *td)
{

#ifdef UFS_EXTATTR
      return (ufs_extattrctl(mp, cmd, filename_vp, attrnamespace,
          attrname, td));
#else
      return (vfs_stdextattrctl(mp, cmd, filename_vp, attrnamespace,
          attrname, td));
#endif
}

static void
ffs_ifree(struct ufsmount *ump, struct inode *ip)
{

      if (ump->um_fstype == UFS1 && ip->i_din1 != NULL)
            uma_zfree(uma_ufs1, ip->i_din1);
      else if (ip->i_din2 != NULL)
            uma_zfree(uma_ufs2, ip->i_din2);
      uma_zfree(uma_inode, ip);
}

static int dobkgrdwrite = 1;
SYSCTL_INT(_debug, OID_AUTO, dobkgrdwrite, CTLFLAG_RW, &dobkgrdwrite, 0,
    "Do background writes (honoring the BV_BKGRDWRITE flag)?");

/*
 * Complete a background write started from bwrite.
 */
static void
ffs_backgroundwritedone(struct buf *bp)
{
      struct bufobj *bufobj;
      struct buf *origbp;

      /*
       * Find the original buffer that we are writing.
       */
      bufobj = bp->b_bufobj;
      BO_LOCK(bufobj);
      if ((origbp = gbincore(bp->b_bufobj, bp->b_lblkno)) == NULL)
            panic("backgroundwritedone: lost buffer");
      /* Grab an extra reference to be dropped by the bufdone() below. */
      bufobj_wrefl(bufobj);
      BO_UNLOCK(bufobj);
      /*
       * Process dependencies then return any unfinished ones.
       */
      if (!LIST_EMPTY(&bp->b_dep))
            buf_complete(bp);
#ifdef SOFTUPDATES
      if (!LIST_EMPTY(&bp->b_dep))
            softdep_move_dependencies(bp, origbp);
#endif
      /*
       * This buffer is marked B_NOCACHE so when it is released
       * by biodone it will be tossed.
       */
      bp->b_flags |= B_NOCACHE;
      bp->b_flags &= ~B_CACHE;
      bufdone(bp);
      BO_LOCK(bufobj);
      /*
       * Clear the BV_BKGRDINPROG flag in the original buffer
       * and awaken it if it is waiting for the write to complete.
       * If BV_BKGRDINPROG is not set in the original buffer it must
       * have been released and re-instantiated - which is not legal.
       */
      KASSERT((origbp->b_vflags & BV_BKGRDINPROG),
          ("backgroundwritedone: lost buffer2"));
      origbp->b_vflags &= ~BV_BKGRDINPROG;
      if (origbp->b_vflags & BV_BKGRDWAIT) {
            origbp->b_vflags &= ~BV_BKGRDWAIT;
            wakeup(&origbp->b_xflags);
      }
      BO_UNLOCK(bufobj);
}


/*
 * Write, release buffer on completion.  (Done by iodone
 * if async).  Do not bother writing anything if the buffer
 * is invalid.
 *
 * Note that we set B_CACHE here, indicating that buffer is
 * fully valid and thus cacheable.  This is true even of NFS
 * now so we set it generally.  This could be set either here 
 * or in biodone() since the I/O is synchronous.  We put it
 * here.
 */
static int
ffs_bufwrite(struct buf *bp)
{
      int oldflags, s;
      struct buf *newbp;

      CTR3(KTR_BUF, "bufwrite(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
      if (bp->b_flags & B_INVAL) {
            brelse(bp);
            return (0);
      }

      oldflags = bp->b_flags;

      if (BUF_REFCNT(bp) == 0)
            panic("bufwrite: buffer is not busy???");
      s = splbio();
      /*
       * If a background write is already in progress, delay
       * writing this block if it is asynchronous. Otherwise
       * wait for the background write to complete.
       */
      BO_LOCK(bp->b_bufobj);
      if (bp->b_vflags & BV_BKGRDINPROG) {
            if (bp->b_flags & B_ASYNC) {
                  BO_UNLOCK(bp->b_bufobj);
                  splx(s);
                  bdwrite(bp);
                  return (0);
            }
            bp->b_vflags |= BV_BKGRDWAIT;
            msleep(&bp->b_xflags, BO_MTX(bp->b_bufobj), PRIBIO, "bwrbg", 0);
            if (bp->b_vflags & BV_BKGRDINPROG)
                  panic("bufwrite: still writing");
      }
      BO_UNLOCK(bp->b_bufobj);

      /* Mark the buffer clean */
      bundirty(bp);

      /*
       * If this buffer is marked for background writing and we
       * do not have to wait for it, make a copy and write the
       * copy so as to leave this buffer ready for further use.
       *
       * This optimization eats a lot of memory.  If we have a page
       * or buffer shortfall we can't do it.
       */
      if (dobkgrdwrite && (bp->b_xflags & BX_BKGRDWRITE) && 
          (bp->b_flags & B_ASYNC) &&
          !vm_page_count_severe() &&
          !buf_dirty_count_severe()) {
            KASSERT(bp->b_iodone == NULL,
                ("bufwrite: needs chained iodone (%p)", bp->b_iodone));

            /* get a new block */
            newbp = geteblk(bp->b_bufsize);

            /*
             * set it to be identical to the old block.  We have to
             * set b_lblkno and BKGRDMARKER before calling bgetvp()
             * to avoid confusing the splay tree and gbincore().
             */
            memcpy(newbp->b_data, bp->b_data, bp->b_bufsize);
            newbp->b_lblkno = bp->b_lblkno;
            newbp->b_xflags |= BX_BKGRDMARKER;
            BO_LOCK(bp->b_bufobj);
            bp->b_vflags |= BV_BKGRDINPROG;
            bgetvp(bp->b_vp, newbp);
            BO_UNLOCK(bp->b_bufobj);
            newbp->b_bufobj = &bp->b_vp->v_bufobj;
            newbp->b_blkno = bp->b_blkno;
            newbp->b_offset = bp->b_offset;
            newbp->b_iodone = ffs_backgroundwritedone;
            newbp->b_flags |= B_ASYNC;
            newbp->b_flags &= ~B_INVAL;

#ifdef SOFTUPDATES
            /* move over the dependencies */
            if (!LIST_EMPTY(&bp->b_dep))
                  softdep_move_dependencies(bp, newbp);
#endif 

            /*
             * Initiate write on the copy, release the original to
             * the B_LOCKED queue so that it cannot go away until
             * the background write completes. If not locked it could go
             * away and then be reconstituted while it was being written.
             * If the reconstituted buffer were written, we could end up
             * with two background copies being written at the same time.
             */
            bqrelse(bp);
            bp = newbp;
      }

      /* Let the normal bufwrite do the rest for us */
      return (bufwrite(bp));
}


static void
ffs_geom_strategy(struct bufobj *bo, struct buf *bp)
{
      struct vnode *vp;
      int error;
      struct buf *tbp;

      vp = bo->__bo_vnode;
      if (bp->b_iocmd == BIO_WRITE) {
            if ((bp->b_flags & B_VALIDSUSPWRT) == 0 &&
                bp->b_vp != NULL && bp->b_vp->v_mount != NULL &&
                (bp->b_vp->v_mount->mnt_kern_flag & MNTK_SUSPENDED) != 0)
                  panic("ffs_geom_strategy: bad I/O");
            bp->b_flags &= ~B_VALIDSUSPWRT;
            if ((vp->v_vflag & VV_COPYONWRITE) &&
                vp->v_rdev->si_snapdata != NULL) {
                  if ((bp->b_flags & B_CLUSTER) != 0) {
                        runningbufwakeup(bp);
                        TAILQ_FOREACH(tbp, &bp->b_cluster.cluster_head,
                                    b_cluster.cluster_entry) {
                              error = ffs_copyonwrite(vp, tbp);
                              if (error != 0 &&
                                  error != EOPNOTSUPP) {
                                    bp->b_error = error;
                                    bp->b_ioflags |= BIO_ERROR;
                                    bufdone(bp);
                                    return;
                              }
                        }
                        bp->b_runningbufspace = bp->b_bufsize;
                        atomic_add_int(&runningbufspace,
                                     bp->b_runningbufspace);
                  } else {
                        error = ffs_copyonwrite(vp, bp);
                        if (error != 0 && error != EOPNOTSUPP) {
                              bp->b_error = error;
                              bp->b_ioflags |= BIO_ERROR;
                              bufdone(bp);
                              return;
                        }
                  }
            }
#ifdef SOFTUPDATES
            if ((bp->b_flags & B_CLUSTER) != 0) {
                  TAILQ_FOREACH(tbp, &bp->b_cluster.cluster_head,
                              b_cluster.cluster_entry) {
                        if (!LIST_EMPTY(&tbp->b_dep))
                              buf_start(tbp);
                  }
            } else {
                  if (!LIST_EMPTY(&bp->b_dep))
                        buf_start(bp);
            }

#endif
      }
      g_vfs_strategy(bo, bp);
}

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