/*      $OpenBSD: ext2fs_vfsops.c,v 1.123 2025/09/20 13:53:36 mpi Exp $ */
/*      $NetBSD: ext2fs_vfsops.c,v 1.1 1997/06/11 09:34:07 bouyer Exp $ */

/*
 * Copyright (c) 1997 Manuel Bouyer.
 * 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.
 * 3. 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        8.14 (Berkeley) 11/28/94
 * Modified for ext2fs by Manuel Bouyer.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/socket.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/disk.h>
#include <sys/mbuf.h>
#include <sys/fcntl.h>
#include <sys/disklabel.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/lock.h>
#include <sys/dkio.h>
#include <sys/specdev.h>

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

#include <ufs/ext2fs/ext2fs.h>
#include <ufs/ext2fs/ext2fs_extern.h>

int ext2fs_sbupdate(struct ufsmount *, int);
static int      e2fs_sbcheck(struct ext2fs *, int);

const struct vfsops ext2fs_vfsops = {
        .vfs_mount      = ext2fs_mount,
        .vfs_start      = ufs_start,
        .vfs_unmount    = ext2fs_unmount,
        .vfs_root       = ufs_root,
        .vfs_quotactl   = ufs_quotactl,
        .vfs_statfs     = ext2fs_statfs,
        .vfs_sync       = ext2fs_sync,
        .vfs_vget       = ext2fs_vget,
        .vfs_fhtovp     = ext2fs_fhtovp,
        .vfs_vptofh     = ext2fs_vptofh,
        .vfs_init       = ext2fs_init,
        .vfs_checkexp   = ufs_check_export,
};

struct pool ext2fs_inode_pool;
struct pool ext2fs_dinode_pool;

extern u_long ext2gennumber;

int
ext2fs_init(struct vfsconf *vfsp)
{
        pool_init(&ext2fs_inode_pool, sizeof(struct inode), 0,
            IPL_NONE, PR_WAITOK, "ext2inopl", NULL);
        pool_init(&ext2fs_dinode_pool, sizeof(struct ext2fs_dinode), 0,
            IPL_NONE, PR_WAITOK, "ext2dinopl", NULL);

        return (ufs_init(vfsp));
}

/*
 * Called by main() when ext2fs is going to be mounted as root.
 */

int
ext2fs_mountroot(void)
{
        struct m_ext2fs *fs;
        struct mount *mp;
        struct proc *p = curproc;       /* XXX */
        struct ufsmount *ump;
        int error;

        /*
         * Get vnodes for swapdev and rootdev.
         */
        if (bdevvp(swapdev, &swapdev_vp) || bdevvp(rootdev, &rootvp))
                panic("ext2fs_mountroot: can't setup bdevvp's");

        if ((error = vfs_rootmountalloc("ext2fs", "root_device", &mp)) != 0) {
                vrele(rootvp);
                return (error);
        }

        if ((error = ext2fs_mountfs(rootvp, mp, p)) != 0) {
                vfs_unbusy(mp);
                vfs_mount_free(mp);
                vrele(rootvp);
                return (error);
        }

        TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
        ump = VFSTOUFS(mp);
        fs = ump->um_e2fs;
        memset(fs->e2fs_fsmnt, 0, sizeof(fs->e2fs_fsmnt));
        strlcpy(fs->e2fs_fsmnt, mp->mnt_stat.f_mntonname, sizeof(fs->e2fs_fsmnt));
        if (fs->e2fs.e2fs_rev > E2FS_REV0) {
                memset(fs->e2fs.e2fs_fsmnt, 0, sizeof(fs->e2fs.e2fs_fsmnt));
                strlcpy(fs->e2fs.e2fs_fsmnt, mp->mnt_stat.f_mntonname,
                    sizeof(fs->e2fs.e2fs_fsmnt));
        }
        (void)ext2fs_statfs(mp, &mp->mnt_stat, p);
        vfs_unbusy(mp);
        inittodr(fs->e2fs.e2fs_wtime);
        return (0);
}

/*
 * VFS Operations.
 *
 * mount system call
 */
int
ext2fs_mount(struct mount *mp, const char *path, void *data,
    struct nameidata *ndp, struct proc *p)
{
        struct vnode *devvp;
        struct ufs_args *args = data;
        struct ufsmount *ump = NULL;
        struct m_ext2fs *fs;
        char fname[MNAMELEN];
        char fspec[MNAMELEN];
        int error, flags;

        /*
         * 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_e2fs;
                if (fs->e2fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
                        flags = WRITECLOSE;
                        if (mp->mnt_flag & MNT_FORCE)
                                flags |= FORCECLOSE;
                        error = ext2fs_flushfiles(mp, flags, p);
                        if (error == 0 &&
                            ext2fs_cgupdate(ump, MNT_WAIT) == 0 &&
                            (fs->e2fs.e2fs_state & E2FS_ERRORS) == 0) {
                                fs->e2fs.e2fs_state = E2FS_ISCLEAN;
                                (void)ext2fs_sbupdate(ump, MNT_WAIT);
                        }
                        if (error)
                                return (error);
                        fs->e2fs_ronly = 1;
                }
                if (mp->mnt_flag & MNT_RELOAD) {
                        error = ext2fs_reload(mp, ndp->ni_cnd.cn_cred, p);
                        if (error)
                                return (error);
                }
                if (fs->e2fs_ronly && (mp->mnt_flag & MNT_WANTRDWR)) {
                        fs->e2fs_ronly = 0;
                        if (fs->e2fs.e2fs_state == E2FS_ISCLEAN)
                                fs->e2fs.e2fs_state = 0;
                        else
                                fs->e2fs.e2fs_state = E2FS_ERRORS;
                        fs->e2fs_fmod = 1;
                }
                if (args && args->fspec == NULL) {
                        /*
                         * Process export requests.
                         */
                        return (vfs_export(mp, &ump->um_export,
                            &args->export_info));
                }
                if (args == NULL)
                        goto success;
        }
        /*
         * Not an update, or updating the name: look up the name
         * and verify that it refers to a sensible block device.
         */
        error = copyinstr(args->fspec, fspec, sizeof(fspec), NULL);
        if (error)
                goto error;

        if (disk_map(fspec, fname, MNAMELEN, DM_OPENBLCK) == -1)
                memcpy(fname, fspec, sizeof(fname));

        NDINIT(ndp, LOOKUP, FOLLOW, UIO_SYSSPACE, fname, p);
        if ((error = namei(ndp)) != 0)
                goto error;
        devvp = ndp->ni_vp;

        if (devvp->v_type != VBLK) {
                error = ENOTBLK;
                goto error_devvp;
        }
        if (major(devvp->v_rdev) >= nblkdev) {
                error = ENXIO;
                goto error_devvp;
        }
        if ((mp->mnt_flag & MNT_UPDATE) == 0)
                error = ext2fs_mountfs(devvp, mp, p);
        else {
                if (devvp != ump->um_devvp)
                        error = EINVAL; /* XXX needs translation */
                else
                        vrele(devvp);
        }
        if (error)
                goto error_devvp;
        ump = VFSTOUFS(mp);
        fs = ump->um_e2fs;

        memset(fs->e2fs_fsmnt, 0, sizeof(fs->e2fs_fsmnt));
        strlcpy(fs->e2fs_fsmnt, path, sizeof(fs->e2fs_fsmnt));
        if (fs->e2fs.e2fs_rev > E2FS_REV0) {
                memset(fs->e2fs.e2fs_fsmnt, 0, sizeof(fs->e2fs.e2fs_fsmnt));
                strlcpy(fs->e2fs.e2fs_fsmnt, mp->mnt_stat.f_mntonname,
                    sizeof(fs->e2fs.e2fs_fsmnt));
        }
        memcpy(mp->mnt_stat.f_mntonname, fs->e2fs_fsmnt, MNAMELEN);
        memset(mp->mnt_stat.f_mntfromname, 0, MNAMELEN);
        strlcpy(mp->mnt_stat.f_mntfromname, fname, MNAMELEN);
        memset(mp->mnt_stat.f_mntfromspec, 0, MNAMELEN);
        strlcpy(mp->mnt_stat.f_mntfromspec, fspec, MNAMELEN);
        memcpy(&mp->mnt_stat.mount_info.ufs_args, args, sizeof(*args));

        if (fs->e2fs_fmod != 0) {       /* XXX */
                fs->e2fs_fmod = 0;
                if (fs->e2fs.e2fs_state == 0)
                        fs->e2fs.e2fs_wtime = gettime();
                else
                        printf("%s: file system not clean; please fsck(8)\n",
                            mp->mnt_stat.f_mntfromname);
                ext2fs_cgupdate(ump, MNT_WAIT);
        }

        goto success;

error_devvp:
        /* Error with devvp held. */
        vrele(devvp);

error:
        /* Error with no state to backout. */

success:
        return (error);
}

int ext2fs_reload_vnode(struct vnode *, void *args);

struct ext2fs_reload_args {
        struct m_ext2fs *fs;
        struct proc *p;
        struct ucred *cred;
        struct vnode *devvp;
};

int
ext2fs_reload_vnode(struct vnode *vp, void *args)
{
        struct ext2fs_reload_args *era = args;
        struct buf *bp;
        struct inode *ip;
        int error;
        caddr_t cp;

        /*
         * Step 4: invalidate all inactive vnodes.
         */
        if (vp->v_usecount == 0) {
                vgonel(vp, era->p);
                return (0);
        }

        /*
         * Step 5: invalidate all cached file data.
         */
        if (vget(vp, LK_EXCLUSIVE))
                return (0);

        if (vinvalbuf(vp, 0, era->cred, era->p, 0, INFSLP))
                panic("ext2fs_reload: dirty2");
        /*
         * Step 6: re-read inode data for all active vnodes.
         */
        ip = VTOI(vp);
        error = bread(era->devvp,
            fsbtodb(era->fs, ino_to_fsba(era->fs, ip->i_number)),
            (int)era->fs->e2fs_bsize, &bp);
        if (error) {
                vput(vp);
                return (error);
        }
        cp = (caddr_t)bp->b_data +
            (ino_to_fsbo(era->fs, ip->i_number) * EXT2_DINODE_SIZE(era->fs));
        e2fs_iload(era->fs, (struct ext2fs_dinode *)cp, ip->i_e2din);
        brelse(bp);
        vput(vp);
        return (0);
}

static off_t
ext2fs_maxfilesize(struct m_ext2fs *fs)
{
        bool huge = fs->e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_HUGE_FILE;
        off_t b = fs->e2fs_bsize / 4;
        off_t physically, logically;

        physically = dbtob(huge ? ((1ULL << 48) - 1) : UINT_MAX);
        logically = (12ULL + b + b*b + b*b*b) * fs->e2fs_bsize;

        return MIN(logically, physically);
}

static int
e2fs_sbfill(struct vnode *devvp, struct m_ext2fs *fs)
{
        struct buf *bp = NULL;
        int i, error;

        /* XXX assume hardware block size == 512 */
        fs->e2fs_ncg = howmany(fs->e2fs.e2fs_bcount - fs->e2fs.e2fs_first_dblock,
            fs->e2fs.e2fs_bpg);
        fs->e2fs_fsbtodb = fs->e2fs.e2fs_log_bsize + 1;
        fs->e2fs_bsize = 1024 << fs->e2fs.e2fs_log_bsize;
        fs->e2fs_bshift = LOG_MINBSIZE + fs->e2fs.e2fs_log_bsize;
        fs->e2fs_fsize = 1024 << fs->e2fs.e2fs_log_fsize;

        fs->e2fs_qbmask = fs->e2fs_bsize - 1;
        fs->e2fs_bmask = ~fs->e2fs_qbmask;

        fs->e2fs_ipb = fs->e2fs_bsize / EXT2_DINODE_SIZE(fs);
        fs->e2fs_itpg = fs->e2fs.e2fs_ipg / fs->e2fs_ipb;

        /* Re-read group descriptors from the disk. */
        fs->e2fs_ngdb = howmany(fs->e2fs_ncg,
            fs->e2fs_bsize / sizeof(struct ext2_gd));
        fs->e2fs_gd = mallocarray(fs->e2fs_ngdb, fs->e2fs_bsize,
            M_UFSMNT, M_WAITOK);

        for (i = 0; i < fs->e2fs_ngdb; ++i) {
                daddr_t dblk = ((fs->e2fs_bsize > 1024) ? 0 : 1) + i + 1;
                size_t gdesc = i * fs->e2fs_bsize / sizeof(struct ext2_gd);
                struct ext2_gd *gd;

                error = bread(devvp, fsbtodb(fs, dblk), fs->e2fs_bsize, &bp);
                if (error) {
                        size_t gdescs_space = fs->e2fs_ngdb * fs->e2fs_bsize;

                        free(fs->e2fs_gd, M_UFSMNT, gdescs_space);
                        fs->e2fs_gd = NULL;
                        brelse(bp);
                        return (error);
                }

                gd = (struct ext2_gd *) bp->b_data;
                e2fs_cgload(gd, fs->e2fs_gd + gdesc, fs->e2fs_bsize);
                brelse(bp);
                bp = NULL;
        }

        if (!(fs->e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_LARGE_FILE) ||
            (fs->e2fs.e2fs_rev == E2FS_REV0))
                fs->e2fs_maxfilesize = INT_MAX;
        else
                fs->e2fs_maxfilesize = ext2fs_maxfilesize(fs);

        if (fs->e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_EXTENTS)
                fs->e2fs_maxfilesize *= 4;

        return (0);
}

/*
 * 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.
 */
int
ext2fs_reload(struct mount *mountp, struct ucred *cred, struct proc *p)
{
        struct vnode *devvp;
        struct buf *bp;
        struct m_ext2fs *fs;
        struct ext2fs *newfs;
        int error;
        struct ext2fs_reload_args era;

        if ((mountp->mnt_flag & MNT_RDONLY) == 0)
                return (EINVAL);
        /*
         * Step 1: invalidate all cached meta-data.
         */
        devvp = VFSTOUFS(mountp)->um_devvp;
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = vinvalbuf(devvp, 0, cred, p, 0, INFSLP);
        VOP_UNLOCK(devvp);
        if (error != 0)
                panic("ext2fs_reload: dirty1");

        /*
         * Step 2: re-read superblock from disk.
         */
        error = bread(devvp, (daddr_t)(SBOFF / DEV_BSIZE), SBSIZE, &bp);
        if (error) {
                brelse(bp);
                return (error);
        }
        newfs = (struct ext2fs *)bp->b_data;
        error = e2fs_sbcheck(newfs, (mountp->mnt_flag & MNT_RDONLY));
        if (error) {
                brelse(bp);
                return (error);
        }

        fs = VFSTOUFS(mountp)->um_e2fs;
        /*
         * Copy in the new superblock, compute in-memory values
         * and load group descriptors.
         */
        e2fs_sbload(newfs, &fs->e2fs);
        if ((error = e2fs_sbfill(devvp, fs)) != 0)
                return (error);

        era.p = p;
        era.cred = cred;
        era.fs = fs;
        era.devvp = devvp;

        error = vfs_mount_foreach_vnode(mountp, ext2fs_reload_vnode, &era);

        return (error);
}

/*
 * Common code for mount and mountroot
 */
int
ext2fs_mountfs(struct vnode *devvp, struct mount *mp, struct proc *p)
{
        struct ufsmount *ump;
        struct buf *bp;
        struct ext2fs *fs;
        dev_t dev;
        int error, ronly;
        struct ucred *cred;

        dev = devvp->v_rdev;
        cred = p ? p->p_ucred : NOCRED;
        /*
         * Disallow multiple mounts of the same device.
         * Disallow mounting of a device that is currently in use
         * (except for root, which might share swap device for miniroot).
         * Flush out any old buffers remaining from a previous use.
         */
        if ((error = vfs_mountedon(devvp)) != 0)
                return (error);
        if (vcount(devvp) > 1 && devvp != rootvp)
                return (EBUSY);
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = vinvalbuf(devvp, V_SAVE, cred, p, 0, INFSLP);
        VOP_UNLOCK(devvp);
        if (error != 0)
                return (error);

        ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
        error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, p);
        if (error)
                return (error);

        bp = NULL;
        ump = NULL;

        /*
         * Read the superblock from disk.
         */
        error = bread(devvp, (daddr_t)(SBOFF / DEV_BSIZE), SBSIZE, &bp);
        if (error)
                goto out;
        fs = (struct ext2fs *)bp->b_data;
        error = e2fs_sbcheck(fs, ronly);
        if (error)
                goto out;

        ump = malloc(sizeof *ump, M_UFSMNT, M_WAITOK | M_ZERO);
        ump->um_e2fs = malloc(sizeof(struct m_ext2fs), M_UFSMNT,
            M_WAITOK | M_ZERO);

        /*
         * Copy in the superblock, compute in-memory values
         * and load group descriptors.
         */
        e2fs_sbload(fs, &ump->um_e2fs->e2fs);
        if ((error = e2fs_sbfill(devvp, ump->um_e2fs)) != 0)
                goto out;
        brelse(bp);
        bp = NULL;
        fs = &ump->um_e2fs->e2fs;
        ump->um_e2fs->e2fs_ronly = ronly;
        ump->um_fstype = UM_EXT2FS;

        if (ronly == 0) {
                if (fs->e2fs_state == E2FS_ISCLEAN)
                        fs->e2fs_state = 0;
                else
                        fs->e2fs_state = E2FS_ERRORS;
                ump->um_e2fs->e2fs_fmod = 1;
        }

        mp->mnt_data = ump;
        mp->mnt_stat.f_fsid.val[0] = (long)dev;
        mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
        mp->mnt_stat.f_namemax = MAXNAMLEN;
        mp->mnt_flag |= MNT_LOCAL;
        ump->um_mountp = mp;
        ump->um_dev = dev;
        ump->um_devvp = devvp;
        ump->um_nindir = NINDIR(ump->um_e2fs);
        ump->um_bptrtodb = ump->um_e2fs->e2fs_fsbtodb;
        ump->um_seqinc = 1; /* no frags */
        ump->um_maxsymlinklen = EXT2_MAXSYMLINKLEN;
        devvp->v_specmountpoint = mp;
        return (0);
out:
        if (devvp->v_specinfo)
                devvp->v_specmountpoint = NULL;
        if (bp)
                brelse(bp);
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        (void)VOP_CLOSE(devvp, ronly ? FREAD : FREAD|FWRITE, cred, p);
        VOP_UNLOCK(devvp);
        if (ump) {
                free(ump->um_e2fs, M_UFSMNT, sizeof *ump->um_e2fs);
                free(ump, M_UFSMNT, sizeof *ump);
                mp->mnt_data = NULL;
        }
        return (error);
}

/*
 * unmount system call
 */
int
ext2fs_unmount(struct mount *mp, int mntflags, struct proc *p)
{
        struct ufsmount *ump;
        struct m_ext2fs *fs;
        int error, flags;
        size_t gdescs_space;

        flags = 0;
        if (mntflags & MNT_FORCE)
                flags |= FORCECLOSE;
        if ((error = ext2fs_flushfiles(mp, flags, p)) != 0)
                return (error);
        ump = VFSTOUFS(mp);
        fs = ump->um_e2fs;
        gdescs_space = fs->e2fs_ngdb * fs->e2fs_bsize;

        if (!fs->e2fs_ronly && ext2fs_cgupdate(ump, MNT_WAIT) == 0 &&
            (fs->e2fs.e2fs_state & E2FS_ERRORS) == 0) {
                fs->e2fs.e2fs_state = E2FS_ISCLEAN;
                (void) ext2fs_sbupdate(ump, MNT_WAIT);
        }

        if (ump->um_devvp->v_type != VBAD)
                ump->um_devvp->v_specmountpoint = NULL;
        vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
        (void)VOP_CLOSE(ump->um_devvp, fs->e2fs_ronly ? FREAD : FREAD|FWRITE,
            NOCRED, p);
        vput(ump->um_devvp);
        free(fs->e2fs_gd, M_UFSMNT, gdescs_space);
        free(fs, M_UFSMNT, sizeof *fs);
        free(ump, M_UFSMNT, sizeof *ump);
        mp->mnt_data = NULL;
        mp->mnt_flag &= ~MNT_LOCAL;
        return (0);
}

/*
 * Flush out all the files in a filesystem.
 */
int
ext2fs_flushfiles(struct mount *mp, int flags, struct proc *p)
{
        struct ufsmount *ump;
        int error;

        ump = VFSTOUFS(mp);
        /*
         * Flush all the files.
         */
        if ((error = vflush(mp, NULL, flags)) != 0)
                return (error);
        /*
         * Flush filesystem metadata.
         */
        vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_FSYNC(ump->um_devvp, p->p_ucred, MNT_WAIT, p);
        VOP_UNLOCK(ump->um_devvp);
        return (error);
}

/*
 * Get file system statistics.
 */
int
ext2fs_statfs(struct mount *mp, struct statfs *sbp, struct proc *p)
{
        struct ufsmount *ump;
        struct m_ext2fs *fs;
        u_int32_t overhead, overhead_per_group;
        int i, ngroups;

        ump = VFSTOUFS(mp);
        fs = ump->um_e2fs;
        if (fs->e2fs.e2fs_magic != E2FS_MAGIC)
                panic("ext2fs_statfs");

        /*
         * Compute the overhead (FS structures)
         */
        overhead_per_group = 1 /* block bitmap */ + 1 /* inode bitmap */ +
            fs->e2fs_itpg;
        overhead = fs->e2fs.e2fs_first_dblock +
            fs->e2fs_ncg * overhead_per_group;
        if (fs->e2fs.e2fs_rev > E2FS_REV0 &&
            fs->e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_SPARSE_SUPER) {
                for (i = 0, ngroups = 0; i < fs->e2fs_ncg; i++) {
                        if (cg_has_sb(i))
                                ngroups++;
                }
        } else {
                ngroups = fs->e2fs_ncg;
        }
        overhead += ngroups * (1 + fs->e2fs_ngdb);

        sbp->f_bsize = fs->e2fs_bsize;
        sbp->f_iosize = fs->e2fs_bsize;
        sbp->f_blocks = fs->e2fs.e2fs_bcount - overhead;
        sbp->f_bfree = fs->e2fs.e2fs_fbcount;
        sbp->f_bavail = sbp->f_bfree - fs->e2fs.e2fs_rbcount;
        sbp->f_files =  fs->e2fs.e2fs_icount;
        sbp->f_favail = sbp->f_ffree = fs->e2fs.e2fs_ficount;
        copy_statfs_info(sbp, mp);

        return (0);
}

int ext2fs_sync_vnode(struct vnode *vp, void *);

struct ext2fs_sync_args {
        int allerror;
        int waitfor;
        int nlink0;
        int inflight;
        struct proc *p;
        struct ucred *cred;
};

int
ext2fs_sync_vnode(struct vnode *vp, void *args)
{
        struct ext2fs_sync_args *esa = args;
        struct inode *ip;
        int error, nlink0 = 0;
        int s, skip = 0;

        if (vp->v_type == VNON)
                return (0);

        ip = VTOI(vp);
        
        if (ip->i_e2fs_nlink == 0)
                nlink0 = 1;

        s = splbio();
        if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0 &&
            LIST_EMPTY(&vp->v_dirtyblkhd)) {
                skip = 1;
        }
        splx(s);

        if (skip)
                goto end;

        if (vget(vp, LK_EXCLUSIVE | LK_NOWAIT)) {
                esa->inflight = MIN(esa->inflight+1, 65536);
                goto end;
        }

        if ((error = VOP_FSYNC(vp, esa->cred, esa->waitfor, esa->p)) != 0)
                esa->allerror = error;
        vput(vp);
end:
        esa->nlink0 = MIN(esa->nlink0 + nlink0, 65536);
        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.
 *
 * Should always be called with the mount point locked.
 */
int
ext2fs_sync(struct mount *mp, int waitfor, int stall,
    struct ucred *cred, struct proc *p)
{
        struct ufsmount *ump = VFSTOUFS(mp);
        struct m_ext2fs *fs;
        int error, allerror = 0, state, fmod;
        struct ext2fs_sync_args esa;

        fs = ump->um_e2fs;
        if (fs->e2fs_ronly != 0) {              /* XXX */
                printf("fs = %s\n", fs->e2fs_fsmnt);
                panic("update: rofs mod");
        }

        /*
         * Write back each (modified) inode.
         */
        esa.p = p;
        esa.cred = cred;
        esa.allerror = 0;
        esa.waitfor = waitfor;
        esa.nlink0 = 0;
        esa.inflight = 0;

        vfs_mount_foreach_vnode(mp, ext2fs_sync_vnode, &esa);
        if (esa.allerror != 0)
                allerror = esa.allerror;

        /*
         * Force stale file system control information to be flushed.
         */
        if (waitfor != MNT_LAZY) {
                vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
                if ((error = VOP_FSYNC(ump->um_devvp, cred, waitfor, p)) != 0)
                        allerror = error;
                VOP_UNLOCK(ump->um_devvp);
        }
        /*
         * Write back modified superblock.
         */
        state = fs->e2fs.e2fs_state;
        fmod = fs->e2fs_fmod;
        if (stall && fs->e2fs_ronly == 0) {
                fs->e2fs_fmod = 1;
                if (allerror == 0 && esa.nlink0 == 0 && esa.inflight == 0) {
                        if ((fs->e2fs.e2fs_state & E2FS_ERRORS) == 0)
                                fs->e2fs.e2fs_state = E2FS_ISCLEAN;
#if 0
                        printf("%s force clean (dangling %d inflight %d)\n",
                            mp->mnt_stat.f_mntonname, esa.nlink0, esa.inflight);
#endif
                } else {
                        fs->e2fs.e2fs_state = 0;
#if 0
                        printf("%s force dirty (dangling %d inflight %d)\n",
                            mp->mnt_stat.f_mntonname, esa.nlink0, esa.inflight);
#endif
                }
        }               
        if (fs->e2fs_fmod != 0) {
                fs->e2fs_fmod = 0;
                fs->e2fs.e2fs_wtime = gettime();
                if ((error = ext2fs_cgupdate(ump, waitfor)))
                        allerror = error;
        }
        fs->e2fs.e2fs_state = state;
        fs->e2fs_fmod = fmod;
        return (allerror);
}

/*
 * Look up a EXT2FS dinode number to find its incore vnode, otherwise read it
 * in from disk.  If it is in core, wait for the lock bit to clear, then
 * return the inode locked.  Detection and handling of mount points must be
 * done by the calling routine.
 */
int
ext2fs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
{
        struct m_ext2fs *fs;
        struct inode *ip;
        struct ext2fs_dinode *dp;
        struct ufsmount *ump;
        struct buf *bp;
        struct vnode *vp;
        dev_t dev;
        int error;

        if (ino > (ufsino_t)-1)
                panic("ext2fs_vget: alien ino_t %llu",
                    (unsigned long long)ino);

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

 retry:
        if ((*vpp = ufs_ihashget(dev, ino)) != NULL)
                return (0);

        /* Allocate a new vnode/inode. */
        if ((error = getnewvnode(VT_EXT2FS, mp, &ext2fs_vops, &vp)) != 0) {
                *vpp = NULL;
                return (error);
        }

        ip = pool_get(&ext2fs_inode_pool, PR_WAITOK|PR_ZERO);
        rrw_init_flags(&ip->i_lock, "inode", RWL_DUPOK | RWL_IS_VNODE);
        vp->v_data = ip;
        ip->i_vnode = vp;
        ip->i_ump = ump;
        ip->i_e2fs = fs = ump->um_e2fs;
        ip->i_dev = dev;
        ip->i_number = ino;
        ip->i_e2fs_last_lblk = 0;
        ip->i_e2fs_last_blk = 0;

        /*
         * Put it onto its hash chain and lock it so that other requests for
         * this inode will block if they arrive while we are sleeping waiting
         * for old data structures to be purged or for the contents of the
         * disk portion of this inode to be read.
         */
        error = ufs_ihashins(ip);

        if (error) {
                vrele(vp);

                if (error == EEXIST)
                        goto retry;

                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->e2fs_bsize, &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().
                 */
                vput(vp);
                brelse(bp);
                *vpp = NULL;
                return (error);
        }

        dp = (struct ext2fs_dinode *) ((char *)bp->b_data
            + EXT2_DINODE_SIZE(fs) * ino_to_fsbo(fs, ino));

        ip->i_e2din = pool_get(&ext2fs_dinode_pool, PR_WAITOK);
        e2fs_iload(fs, dp, ip->i_e2din);
        brelse(bp);

        ip->i_effnlink = ip->i_e2fs_nlink;

        /*
         * The fields for storing the UID and GID of an ext2fs inode are
         * limited to 16 bits. To overcome this limitation, Linux decided to
         * scatter the highest bits of these values into a previously reserved
         * area on the disk inode. We deal with this situation by having two
         * 32-bit fields *out* of the disk inode to hold the complete values.
         * Now that we are reading in the inode, compute these fields.
         */
        ip->i_e2fs_uid = ip->i_e2fs_uid_low | (ip->i_e2fs_uid_high << 16);
        ip->i_e2fs_gid = ip->i_e2fs_gid_low | (ip->i_e2fs_gid_high << 16);

        /* If the inode was deleted, reset all fields */
        if (ip->i_e2fs_dtime != 0) {
                ip->i_e2fs_mode = ip->i_e2fs_nblock = 0;
                (void)ext2fs_setsize(ip, 0);
        }

        /*
         * Initialize the vnode from the inode, check for aliases.
         * Note that the underlying vnode may have changed.
         */
        error = ext2fs_vinit(mp, &vp);
        if (error) {
                vput(vp);
                *vpp = NULL;
                return (error);
        }

        /*
         * Finish inode initialization now that aliasing has been resolved.
         */
        vref(ip->i_devvp);
        /*
         * 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_e2fs_gen == 0) {
                if (++ext2gennumber < (u_long)gettime())
                        ext2gennumber = gettime();
                ip->i_e2fs_gen = ext2gennumber;
                if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0)
                        ip->i_flag |= IN_MODIFIED;
        }

        *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 ext2fs_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
 */
int
ext2fs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
{
        struct inode *ip;
        struct vnode *nvp;
        int error;
        struct ufid *ufhp;
        struct m_ext2fs *fs;

        ufhp = (struct ufid *)fhp;
        fs = VFSTOUFS(mp)->um_e2fs;
        if ((ufhp->ufid_ino < EXT2_FIRSTINO && ufhp->ufid_ino != EXT2_ROOTINO) ||
            ufhp->ufid_ino > fs->e2fs_ncg * fs->e2fs.e2fs_ipg)
                return (ESTALE);

        if ((error = VFS_VGET(mp, ufhp->ufid_ino, &nvp)) != 0) {
                *vpp = NULL;
                return (error);
        }
        ip = VTOI(nvp);
        if (ip->i_e2fs_mode == 0 || ip->i_e2fs_dtime != 0 ||
            ip->i_e2fs_gen != ufhp->ufid_gen) {
                vput(nvp);
                *vpp = NULL;
                return (ESTALE);
        }
        *vpp = nvp;
        return (0);
}

/*
 * Vnode pointer to File handle
 */
int
ext2fs_vptofh(struct vnode *vp, struct fid *fhp)
{
        struct inode *ip;
        struct ufid *ufhp;

        ip = VTOI(vp);
        ufhp = (struct ufid *)fhp;
        ufhp->ufid_len = sizeof(struct ufid);
        ufhp->ufid_ino = ip->i_number;
        ufhp->ufid_gen = ip->i_e2fs_gen;
        return (0);
}

/*
 * Write a superblock and associated information back to disk.
 */
int
ext2fs_sbupdate(struct ufsmount *mp, int waitfor)
{
        struct m_ext2fs *fs = mp->um_e2fs;
        struct buf *bp;
        int error = 0;

        bp = getblk(mp->um_devvp, SBLOCK, SBSIZE, 0, INFSLP);
        e2fs_sbsave(&fs->e2fs, (struct ext2fs *) bp->b_data);
        if (waitfor == MNT_WAIT)
                error = bwrite(bp);
        else
                bawrite(bp);
        fs->e2fs_fmod = 0;
        return (error);
}

int
ext2fs_cgupdate(struct ufsmount *mp, int waitfor)
{
        struct m_ext2fs *fs = mp->um_e2fs;
        struct buf *bp;
        int i, error = 0, allerror = 0;

        allerror = ext2fs_sbupdate(mp, waitfor);
        for (i = 0; i < fs->e2fs_ngdb; i++) {
                bp = getblk(mp->um_devvp, fsbtodb(fs, ((fs->e2fs_bsize>1024)?0:1)+i+1),
                    fs->e2fs_bsize, 0, INFSLP);
                e2fs_cgsave(&fs->e2fs_gd[i* fs->e2fs_bsize / sizeof(struct ext2_gd)], (struct ext2_gd*)bp->b_data, fs->e2fs_bsize);
                if (waitfor == MNT_WAIT)
                        error = bwrite(bp);
                else
                        bawrite(bp);
        }

        if (!allerror && error)
                allerror = error;
        return (allerror);
}

/* This is called before the superblock is copied.  Watch out for endianness! */
static int
e2fs_sbcheck(struct ext2fs *fs, int ronly)
{
        u_int32_t mask, tmp;
        int i;

        tmp = letoh16(fs->e2fs_magic);
        if (tmp != E2FS_MAGIC) {
                printf("ext2fs: wrong magic number 0x%x\n", tmp);
                return (EIO);           /* XXX needs translation */
        }

        tmp = letoh32(fs->e2fs_log_bsize);
        if (tmp > 2) {
                /* skewed log(block size): 1024 -> 0 | 2048 -> 1 | 4096 -> 2 */
                tmp += 10;
                printf("ext2fs: wrong log2(block size) %d\n", tmp);
                return (EIO);      /* XXX needs translation */
        }

        if (fs->e2fs_bpg == 0) {
                printf("ext2fs: zero blocks per group\n");
                return (EIO);
        }

        tmp = letoh32(fs->e2fs_rev);
        if (tmp > E2FS_REV1) {
                printf("ext2fs: wrong revision number 0x%x\n", tmp);
                return (EIO);           /* XXX needs translation */
        }
        else if (tmp == E2FS_REV0)
                return (0);

        tmp = letoh32(fs->e2fs_first_ino);
        if (tmp != EXT2_FIRSTINO) {
                printf("ext2fs: first inode at 0x%x\n", tmp);
                return (EINVAL);      /* XXX needs translation */
        }

        tmp = letoh32(fs->e2fs_features_incompat);
        mask = tmp & ~(EXT2F_INCOMPAT_SUPP | EXT4F_RO_INCOMPAT_SUPP);
        if (mask) {
                printf("ext2fs: unsupported incompat features: ");
                for (i = 0; i < nitems(incompat); i++)
                        if (mask & incompat[i].mask)
                                printf("%s ", incompat[i].name);
                printf("\n");
                return (EINVAL);      /* XXX needs translation */
        }

        if (!ronly && (tmp & EXT4F_RO_INCOMPAT_SUPP)) {
                printf("ext4fs: only read-only support right now\n");
                return (EROFS);      /* XXX needs translation */
        }

        if (tmp & EXT2F_INCOMPAT_RECOVER) {
                printf("ext2fs: your file system says it needs recovery\n");
                if (!ronly)
                        return (EROFS); /* XXX needs translation */
        }

        tmp = letoh32(fs->e2fs_features_rocompat) & ~EXT2F_ROCOMPAT_SUPP;
        if (!ronly && tmp) {
                printf("ext2fs: unsupported R/O compat features: ");
                for (i = 0; i < nitems(ro_compat); i++)
                        if (tmp & ro_compat[i].mask)
                                printf("%s ", ro_compat[i].name);
                printf("\n");
                return (EROFS);      /* XXX needs translation */
        }

        return (0);
}