kernel/ext2fs: Fix -Wundef.

[dragonfly.git] / sys / gnu / vfs / ext2fs / ext2_vfsops.c

/*
 *  modified for EXT2FS support in Lites 1.1
 *
 *  Aug 1995, Godmar Back (gback@cs.utah.edu)
 *  University of Utah, Department of Computer Science
 */
/*
 * 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        8.8 (Berkeley) 4/18/94
 *      $FreeBSD: src/sys/gnu/ext2fs/ext2_vfsops.c,v 1.63.2.7 2002/07/01 00:18:51 iedowse Exp $
 */

#include "opt_quota.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/nlookup.h>
#include <sys/proc.h>
#include <sys/priv.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/diskslice.h>
#include <sys/malloc.h>
#include <sys/stat.h>
#include <vm/vm_zone.h>

#include <sys/buf2.h>
#include <sys/thread2.h>

#include "quota.h"
#include "dinode.h"
#include "inode.h"
#include "ext2_mount.h"
#include "ext2_extern.h"

#include "fs.h"
#include "ext2_fs.h"
#include "ext2_fs_sb.h"

extern struct vop_ops ext2_vnode_vops;
extern struct vop_ops ext2_spec_vops;
extern struct vop_ops ext2_fifo_vops;

static int ext2_fhtovp (struct mount *, struct vnode *,
                                struct fid *, struct vnode **);
static int ext2_flushfiles (struct mount *mp, int flags);
static int ext2_mount (struct mount *, char *, caddr_t, struct ucred *);
static int ext2_mountfs (struct vnode *, struct mount *, struct ucred *);
static int ext2_root(struct mount *, struct vnode **);
static int ext2_reload (struct mount *mountp, struct ucred *cred);
static int ext2_sbupdate (struct ext2_mount *, int);
static int ext2_sync (struct mount *, int);
static int ext2_unmount (struct mount *, int);
static int ext2_vget (struct mount *, struct vnode *, ino_t, struct vnode **);
static int ext2_init(struct vfsconf *);
static int ext2_vptofh (struct vnode *, struct fid *);

static MALLOC_DEFINE(M_EXT2NODE, "EXT2 node", "EXT2 vnode private part");
MALLOC_DEFINE(M_EXT2MNT, "EXT2 mount", "EXT2 mount structure");

static struct vfsops ext2fs_vfsops = {
        .vfs_mount =            ext2_mount,
        .vfs_unmount =          ext2_unmount,
        .vfs_root =             ext2_root,      /* root inode via vget */
        .vfs_quotactl =         ext2_quotactl,  /* quota operations */
        .vfs_statfs =           ext2_statfs,
        .vfs_sync =             ext2_sync,
        .vfs_vget =             ext2_vget,
        .vfs_fhtovp =           ext2_fhtovp,
        .vfs_checkexp =         ext2_check_export,
        .vfs_vptofh =           ext2_vptofh,
        .vfs_init =             ext2_init,
        .vfs_uninit =           ext2_uninit
};

VFS_SET(ext2fs_vfsops, ext2fs, 0);
MODULE_VERSION(ext2fs, 1);

static int ext2fs_inode_hash_lock;

static int      ext2_check_sb_compat (struct ext2_super_block *es,
                                          cdev_t dev, int ronly);
static int      compute_sb_data (struct vnode *devvp,
                                     struct ext2_super_block *es,
                                     struct ext2_sb_info *fs);

static int
ext2_root(struct mount *mp, struct vnode **vpp)
{
        struct vnode *nvp;
        int error;

        error = VFS_VGET(mp, NULL, (ino_t)EXT2_ROOTINO, &nvp);
        if (error)
                return (error);
        *vpp = nvp;
        return (0);
}

/*
 * Do operations associated with quotas
 */
int
ext2_quotactl(struct mount *mp, int cmds, uid_t uid, caddr_t arg,
             struct ucred *cred)
{
#ifndef QUOTA
        return (EOPNOTSUPP);
#else
        int cmd, type, error;

        type = cmds & SUBCMDMASK;
        cmd = cmds >> SUBCMDSHIFT;

        if (uid == -1) {
                switch(type) {
                        case USRQUOTA:
                                uid = cred->cr_ruid;
                                break;
                        case GRPQUOTA:
                                uid = cred->cr_rgid;
                                break;
                        default:
                                return (EINVAL);
                }
        }

        /*
         * Check permissions.
         */
        switch (cmd) {

        case Q_QUOTAON:
                error = priv_check_cred(cred, PRIV_UFS_QUOTAON, 0);
                break;

        case Q_QUOTAOFF:
                error = priv_check_cred(cred, PRIV_UFS_QUOTAOFF, 0);
                break;

        case Q_SETQUOTA:
                error = priv_check_cred(cred, PRIV_VFS_SETQUOTA, 0);
                break;

        case Q_SETUSE:
                error = priv_check_cred(cred, PRIV_UFS_SETUSE, 0);
                break;

        case Q_GETQUOTA:
                if (uid == cred->cr_ruid)
                        error = 0;
                else
                        error = priv_check_cred(cred, PRIV_VFS_GETQUOTA, 0);
                break;

        case Q_SYNC:
                error = 0;
                break;

        default:
                error = EINVAL;
                break;
        }

        if (error)
                return (error);


        if ((uint)type >= MAXQUOTAS)
                return (EINVAL);
        if (vfs_busy(mp, LK_NOWAIT))
                return (0);

        switch (cmd) {

        case Q_QUOTAON:
                error = ext2_quotaon(cred, mp, type, arg);
                break;

        case Q_QUOTAOFF:
                error = ext2_quotaoff(mp, type);
                break;

        case Q_SETQUOTA:
                error = ext2_setquota(mp, uid, type, arg);
                break;

        case Q_SETUSE:
                error = ext2_setuse(mp, uid, type, arg);
                break;

        case Q_GETQUOTA:
                error = ext2_getquota(mp, uid, type, arg);
                break;

        case Q_SYNC:
                error = ext2_qsync(mp);
                break;

        default:
                error = EINVAL;
                break;
        }
        vfs_unbusy(mp);
        return (error);
#endif
}

/*
 * Initial UFS filesystems, done only once.
 */
static int
ext2_init(struct vfsconf *vfsp)
{
        static int done;

        if (done)
                return (0);
        done = 1;
        ext2_ihashinit();
#ifdef QUOTA
        ext2_dqinit();
#endif
        return (0);
}

/*
 * VFS Operations.
 *
 * mount system call
 *
 * Parameters:
 *      data:   this is actually a (struct ext2_args *)
 */
static int
ext2_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
{
        struct vnode *devvp;
        struct ext2_args args;
        struct ext2_mount *ump = NULL;
        struct ext2_sb_info *fs;
        size_t size;
        int error, flags;
        mode_t accessmode;
        struct nlookupdata nd;

        if ((error = copyin(data, (caddr_t)&args, sizeof (struct ext2_args))) != 0)
                return (error);

        /*
         * 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 = VFSTOEXT2(mp);
                fs = ump->um_e2fs;
                devvp = ump->um_devvp;
                error = 0;
                if (fs->s_rd_only == 0 && (mp->mnt_flag & MNT_RDONLY)) {
                        flags = WRITECLOSE;
                        if (mp->mnt_flag & MNT_FORCE)
                                flags |= FORCECLOSE;
                        if (vfs_busy(mp, LK_NOWAIT))
                                return (EBUSY);
                        error = ext2_flushfiles(mp, flags);
                        vfs_unbusy(mp);
                        if (!error && fs->s_wasvalid) {
                                fs->s_es->s_state |= EXT2_VALID_FS;
                                ext2_sbupdate(ump, MNT_WAIT);
                        }
                        fs->s_rd_only = 1;
                        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
                        VOP_OPEN(devvp, FREAD, FSCRED, NULL);
                        VOP_CLOSE(devvp, FREAD|FWRITE, NULL);
                        vn_unlock(devvp);
                }
                if (!error && (mp->mnt_flag & MNT_RELOAD))
                        error = ext2_reload(mp, cred);
                if (error)
                        return (error);
                if (ext2_check_sb_compat(fs->s_es, devvp->v_rdev,
                    (mp->mnt_kern_flag & MNTK_WANTRDWR) == 0) != 0)
                        return (EPERM);
                if (fs->s_rd_only && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
                        /*
                         * If upgrade to read-write by non-root, then verify
                         * that user has necessary permissions on the device.
                         */
                        if (cred->cr_uid != 0) {
                                vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
                                error = VOP_EACCESS(devvp, VREAD | VWRITE, cred);
                                if (error) {
                                        vn_unlock(devvp);
                                        return (error);
                                }
                                vn_unlock(devvp);
                        }

                        if ((fs->s_es->s_state & EXT2_VALID_FS) == 0 ||
                            (fs->s_es->s_state & EXT2_ERROR_FS)) {
                                if (mp->mnt_flag & MNT_FORCE) {
                                        kprintf(
"WARNING: %s was not properly dismounted\n",
                                            fs->fs_fsmnt);
                                } else {
                                        kprintf(
"WARNING: R/W mount of %s denied.  Filesystem is not clean - run fsck\n",
                                            fs->fs_fsmnt);
                                        return (EPERM);
                                }
                        }
                        fs->s_es->s_state &= ~EXT2_VALID_FS;
                        ext2_sbupdate(ump, MNT_WAIT);
                        fs->s_rd_only = 0;
                        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
                        VOP_OPEN(devvp, FREAD|FWRITE, FSCRED, NULL);
                        VOP_CLOSE(devvp, FREAD, NULL);
                        vn_unlock(devvp);
                }
                if (args.fspec == NULL) {
                        /*
                         * Process export requests.
                         */
                        return (vfs_export(mp, &ump->um_export, &args.export));
                }
        }
        /*
         * Not an update, or updating the name: look up the name
         * and verify that it refers to a sensible block device.
         */
        devvp = NULL;
        error = nlookup_init(&nd, args.fspec, UIO_USERSPACE, NLC_FOLLOW);
        if (error == 0)
                error = nlookup(&nd);
        if (error == 0)
                error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
        nlookup_done(&nd);
        if (error)
                return (error);

        if (!vn_isdisk(devvp, &error)) {
                vrele(devvp);
                return (error);
        }

        /*
         * If mount by non-root, then verify that user has necessary
         * permissions on the device.
         */
        if (cred->cr_uid != 0) {
                accessmode = VREAD;
                if ((mp->mnt_flag & MNT_RDONLY) == 0)
                        accessmode |= VWRITE;
                vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
                if ((error = VOP_EACCESS(devvp, accessmode, cred)) != 0) {
                        vput(devvp);
                        return (error);
                }
                vn_unlock(devvp);
        }

        if ((mp->mnt_flag & MNT_UPDATE) == 0) {
                error = ext2_mountfs(devvp, mp, cred);
        } else {
                if (devvp != ump->um_devvp)
                        error = EINVAL; /* needs translation */
                else
                        vrele(devvp);
        }
        if (error) {
                vrele(devvp);
                return (error);
        }
        ump = VFSTOEXT2(mp);
        fs = ump->um_e2fs;
        copyinstr(path, fs->fs_fsmnt, sizeof(fs->fs_fsmnt) - 1, &size);
        bzero(fs->fs_fsmnt + size, sizeof(fs->fs_fsmnt) - size);
        copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
        bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
        ext2_statfs(mp, &mp->mnt_stat, cred);
        return (0);
}

static int
ext2_check_sb_compat(struct ext2_super_block *es, cdev_t dev, int ronly)
{
        if (es->s_magic != EXT2_SUPER_MAGIC) {
                kprintf("ext2fs: %s: wrong magic number %#x (expected %#x)\n",
                    devtoname(dev), es->s_magic, EXT2_SUPER_MAGIC);
                return (1);
        }
        if (es->s_rev_level > EXT2_GOOD_OLD_REV) {
                if (es->s_feature_incompat & ~EXT2_FEATURE_INCOMPAT_SUPP) {
                        kprintf(
"WARNING: mount of %s denied due to unsupported optional features\n",
                            devtoname(dev));
                        return (1);
                }
                if (!ronly &&
                    (es->s_feature_ro_compat & ~EXT2_FEATURE_RO_COMPAT_SUPP)) {
                        kprintf(
"WARNING: R/W mount of %s denied due to unsupported optional features\n",
                            devtoname(dev));
                        return (1);
                }
        }
        return (0);
}

/*
 * this computes the fields of the  ext2_sb_info structure from the
 * data in the ext2_super_block structure read in
 */
static int
compute_sb_data(struct vnode *devvp, struct ext2_super_block *es,
                struct ext2_sb_info *fs)
{
        int db_count, error;
        int i, j;
        int logic_sb_block = 1; /* XXX for now */

#if 1
#define V(v)
#else
#define V(v)  kprintf(#v"= %d\n", fs->v);
#endif

        fs->s_blocksize = EXT2_MIN_BLOCK_SIZE << es->s_log_block_size;
        V(s_blocksize)
        fs->s_bshift = EXT2_MIN_BLOCK_LOG_SIZE + es->s_log_block_size;
        V(s_bshift)
        fs->s_fsbtodb = es->s_log_block_size + 1;
        V(s_fsbtodb)
        fs->s_qbmask = fs->s_blocksize - 1;
        V(s_bmask)
        fs->s_blocksize_bits = EXT2_BLOCK_SIZE_BITS(es);
        V(s_blocksize_bits)
        fs->s_frag_size = EXT2_MIN_FRAG_SIZE << es->s_log_frag_size;
        V(s_frag_size)
        if (fs->s_frag_size)
                fs->s_frags_per_block = fs->s_blocksize / fs->s_frag_size;
        V(s_frags_per_block)
        fs->s_blocks_per_group = es->s_blocks_per_group;
        V(s_blocks_per_group)
        fs->s_frags_per_group = es->s_frags_per_group;
        V(s_frags_per_group)
        fs->s_inodes_per_group = es->s_inodes_per_group;
        V(s_inodes_per_group)
        if (es->s_rev_level == EXT2_GOOD_OLD_REV) {
                fs->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
                fs->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
        } else {
                fs->s_first_ino = es->s_first_ino;
                fs->s_inode_size = es->s_inode_size;
                /*
                 * Simple sanity check for superblock inode size value.
                 */
                if (fs->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE ||
                    fs->s_inode_size > fs->s_blocksize ||
                    (fs->s_inode_size & (fs->s_inode_size - 1)) != 0) {
                        kprintf("EXT2-fs: invalid inode size %d\n",
                        fs->s_inode_size);
                        return (EIO);
                }
        }
        V(s_first_ino)
        V(s_inode_size)
        fs->s_inodes_per_block = fs->s_blocksize / EXT2_INODE_SIZE(fs);
        V(s_inodes_per_block)
        fs->s_itb_per_group = fs->s_inodes_per_group /fs->s_inodes_per_block;
        V(s_itb_per_group)
        fs->s_desc_per_block = fs->s_blocksize / sizeof (struct ext2_group_desc);
        V(s_desc_per_block)
        /* s_resuid / s_resgid ? */
        fs->s_groups_count = (es->s_blocks_count - es->s_first_data_block +
                              EXT2_BLOCKS_PER_GROUP(fs) - 1) /
                              EXT2_BLOCKS_PER_GROUP(fs);
        V(s_groups_count)
        db_count = (fs->s_groups_count + EXT2_DESC_PER_BLOCK(fs) - 1) /
                                         EXT2_DESC_PER_BLOCK(fs);
        fs->s_db_per_group = db_count;
        V(s_db_per_group)

        fs->s_group_desc = kmalloc(db_count * sizeof (struct buf *),
                                M_EXT2MNT, M_WAITOK);

        /* adjust logic_sb_block */
        if (fs->s_blocksize > SBSIZE)
                /*
                 * Godmar thinks: if the blocksize is greater than 1024,
                 * then, the superblock is logically part of block zero.
                 */
                logic_sb_block = 0;

        for (i = 0; i < db_count; i++) {
                error = bread(devvp, fsbtodoff(fs, logic_sb_block + i + 1),
                                fs->s_blocksize, &fs->s_group_desc[i]);
                if (error) {
                        for (j = 0; j < i; j++)
                                brelse(fs->s_group_desc[j]);
                        kfree(fs->s_group_desc, M_EXT2MNT);
                        kprintf("EXT2-fs: unable to read group descriptors (%d)\n", error);
                        return EIO;
                }
                /* Set the B_LOCKED flag on the buffer, then brelse() it */
                LCK_BUF(fs->s_group_desc[i])
        }
        if (!ext2_check_descriptors(fs)) {
                for (j = 0; j < db_count; j++)
                        ULCK_BUF(fs->s_group_desc[j])
                kfree(fs->s_group_desc, M_EXT2MNT);
                kprintf("EXT2-fs: (ext2_check_descriptors failure) "
                        "unable to read group descriptors\n");
                return EIO;
        }

        for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++) {
                fs->s_inode_bitmap_number[i] = 0;
                fs->s_inode_bitmap[i] = NULL;
                fs->s_block_bitmap_number[i] = 0;
                fs->s_block_bitmap[i] = NULL;
        }
        fs->s_loaded_inode_bitmaps = 0;
        fs->s_loaded_block_bitmaps = 0;
        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.
 */
static int ext2_reload_scan(struct mount *mp, struct vnode *vp, void *rescan);

struct scaninfo {
        int rescan;
        int allerror;
        int waitfor;
        struct vnode *devvp;
        struct ext2_sb_info *fs;
};

static int
ext2_reload(struct mount *mountp, struct ucred *cred)
{
        struct vnode *devvp;
        struct buf *bp;
        struct ext2_super_block *es;
        struct ext2_sb_info *fs;
        int error;
        struct scaninfo scaninfo;

        if ((mountp->mnt_flag & MNT_RDONLY) == 0)
                return (EINVAL);
        /*
         * Step 1: invalidate all cached meta-data.
         */
        devvp = VFSTOEXT2(mountp)->um_devvp;
        if (vinvalbuf(devvp, 0, 0, 0))
                panic("ext2_reload: dirty1");
        /*
         * Step 2: re-read superblock from disk.
         * constants have been adjusted for ext2
         */
        if ((error = bread(devvp, SBOFF, SBSIZE, &bp)) != 0)
                return (error);
        es = (struct ext2_super_block *)bp->b_data;
        if (ext2_check_sb_compat(es, devvp->v_rdev, 0) != 0) {
                brelse(bp);
                return (EIO);           /* XXX needs translation */
        }
        fs = VFSTOEXT2(mountp)->um_e2fs;
        bcopy(bp->b_data, fs->s_es, sizeof(struct ext2_super_block));

        if((error = compute_sb_data(devvp, es, fs)) != 0) {
                brelse(bp);
                return error;
        }
#ifdef UNKLAR
        if (fs->fs_sbsize < SBSIZE)
                bp->b_flags |= B_INVAL;
#endif
        brelse(bp);

        scaninfo.rescan = 1;
        scaninfo.devvp = devvp;
        scaninfo.fs = fs;
        while (error == 0 && scaninfo.rescan) {
            scaninfo.rescan = 0;
            error = vmntvnodescan(mountp, VMSC_GETVX,
                                  NULL, ext2_reload_scan, &scaninfo);
        }
        return(error);
}

static int
ext2_reload_scan(struct mount *mp, struct vnode *vp, void *data)
{
        struct scaninfo *info = data;
        struct inode *ip;
        struct buf *bp;
        int error;

        /*
         * Try to recycle
         */
        if (vrecycle(vp))
                return(0);

        /*
         * Step 1: invalidate all cached file data.
         */
        if (vinvalbuf(vp, 0, 0, 0))
                panic("ext2_reload: dirty2");
        /*
         * Step 2: re-read inode data for all active vnodes.
         */
        ip = VTOI(vp);
        error = bread(info->devvp,
                      fsbtodoff(info->fs, ino_to_fsba(info->fs, ip->i_number)),
                      (int)info->fs->s_blocksize, &bp);
        if (error)
                return (error);
        ext2_ei2di((struct ext2_inode *) ((char *)bp->b_data +
            EXT2_INODE_SIZE(info->fs) * ino_to_fsbo(info->fs, ip->i_number)),
            &ip->i_din);
        brelse(bp);
        return(0);
}

/*
 * Common code for mount and mountroot
 */
static int
ext2_mountfs(struct vnode *devvp, struct mount *mp, struct ucred *cred)
{
        struct ext2_mount *ump;
        struct buf *bp;
        struct ext2_sb_info *fs;
        struct ext2_super_block *es;
        cdev_t dev;
        int error, i;
        int ronly;

        /*
         * 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) > 0)
                return (EBUSY);
        if ((error = vinvalbuf(devvp, V_SAVE, 0, 0)) != 0)
                return (error);
#ifdef READONLY
/* turn on this to force it to be read-only */
        mp->mnt_flag |= MNT_RDONLY;
#endif

        ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, NULL);
        vn_unlock(devvp);
        if (error)
                return (error);
        dev = devvp->v_rdev;
        if (dev->si_iosize_max != 0)
                mp->mnt_iosize_max = dev->si_iosize_max;
        if (mp->mnt_iosize_max > MAXPHYS)
                mp->mnt_iosize_max = MAXPHYS;

        bp = NULL;
        ump = NULL;
        if ((error = bread(devvp, SBOFF, SBSIZE, &bp)) != 0)
                goto out;
        es = (struct ext2_super_block *)bp->b_data;
        if (ext2_check_sb_compat(es, dev, ronly) != 0) {
                error = EINVAL;         /* XXX needs translation */
                goto out;
        }
        if ((es->s_state & EXT2_VALID_FS) == 0 ||
            (es->s_state & EXT2_ERROR_FS)) {
                if (ronly || (mp->mnt_flag & MNT_FORCE)) {
                        kprintf(
"WARNING: Filesystem was not properly dismounted\n");
                } else {
                        kprintf(
"WARNING: R/W mount denied.  Filesystem is not clean - run fsck\n");
                        error = EPERM;
                        goto out;
                }
        }
        ump = kmalloc(sizeof *ump, M_EXT2MNT, M_WAITOK | M_ZERO);
        ump->um_malloctype = M_EXT2NODE;
        ump->um_blkatoff = ext2_blkatoff;
        ump->um_truncate = ext2_truncate;
        ump->um_update = ext2_update;
        ump->um_valloc = ext2_valloc;
        ump->um_vfree = ext2_vfree;
        /* I don't know whether this is the right strategy. Note that
           we dynamically allocate both a ext2_sb_info and a ext2_super_block
           while Linux keeps the super block in a locked buffer
         */
        ump->um_e2fs = kmalloc(sizeof(struct ext2_sb_info),
                M_EXT2MNT, M_WAITOK);
        ump->um_e2fs->s_es = kmalloc(sizeof(struct ext2_super_block),
                M_EXT2MNT, M_WAITOK);
        bcopy(es, ump->um_e2fs->s_es, (u_int)sizeof(struct ext2_super_block));
        if ((error = compute_sb_data(devvp, ump->um_e2fs->s_es, ump->um_e2fs)))
                goto out;
        /*
         * We don't free the group descriptors allocated by compute_sb_data()
         * until ext2_unmount().  This is OK since the mount will succeed.
         */
        brelse(bp);
        bp = NULL;
        fs = ump->um_e2fs;
        fs->s_rd_only = ronly;  /* ronly is set according to mnt_flags */
        /* if the fs is not mounted read-only, make sure the super block is
           always written back on a sync()
         */
        fs->s_wasvalid = fs->s_es->s_state & EXT2_VALID_FS ? 1 : 0;
        if (ronly == 0) {
                fs->s_dirt = 1;         /* mark it modified */
                fs->s_es->s_state &= ~EXT2_VALID_FS;    /* set fs invalid */
        }
        mp->mnt_data = (qaddr_t)ump;
        mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
        mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
        mp->mnt_maxsymlinklen = EXT2_MAXSYMLINKLEN;
        mp->mnt_flag |= MNT_LOCAL;
        ump->um_mountp = mp;
        ump->um_dev = dev;
        ump->um_devvp = devvp;
        /* setting those two parameters allows us to use
           ext2_bmap w/o changse !
        */
        ump->um_nindir = EXT2_ADDR_PER_BLOCK(fs);
        ump->um_bptrtodb = fs->s_es->s_log_block_size + 1;
        ump->um_seqinc = EXT2_FRAGS_PER_BLOCK(fs);
        for (i = 0; i < MAXQUOTAS; i++)
                ump->um_quotas[i] = NULLVP;
        dev->si_mountpoint = mp;

        vfs_add_vnodeops(mp, &ext2_vnode_vops, &mp->mnt_vn_norm_ops);
        vfs_add_vnodeops(mp, &ext2_spec_vops, &mp->mnt_vn_spec_ops);
        vfs_add_vnodeops(mp, &ext2_fifo_vops, &mp->mnt_vn_fifo_ops);

        if (ronly == 0)
                ext2_sbupdate(ump, MNT_WAIT);
        return (0);
out:
        if (bp)
                brelse(bp);
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        VOP_CLOSE(devvp, ronly ? FREAD : FREAD|FWRITE, NULL);
        vn_unlock(devvp);
        if (ump) {
                kfree(ump->um_e2fs->s_es, M_EXT2MNT);
                kfree(ump->um_e2fs, M_EXT2MNT);
                kfree(ump, M_EXT2MNT);
                mp->mnt_data = (qaddr_t)0;
        }
        return (error);
}

/*
 * unmount system call
 */
static int
ext2_unmount(struct mount *mp, int mntflags)
{
        struct ext2_mount *ump;
        struct ext2_sb_info *fs;
        int error, flags, ronly, i;

        flags = 0;
        if (mntflags & MNT_FORCE) {
                if (mp->mnt_flag & MNT_ROOTFS)
                        return (EINVAL);
                flags |= FORCECLOSE;
        }
        if ((error = ext2_flushfiles(mp, flags)) != 0)
                return (error);
        ump = VFSTOEXT2(mp);
        fs = ump->um_e2fs;
        ronly = fs->s_rd_only;
        if (ronly == 0) {
                if (fs->s_wasvalid)
                        fs->s_es->s_state |= EXT2_VALID_FS;
                ext2_sbupdate(ump, MNT_WAIT);
        }

        /* release buffers containing group descriptors */
        for(i = 0; i < fs->s_db_per_group; i++)
                ULCK_BUF(fs->s_group_desc[i])
        kfree(fs->s_group_desc, M_EXT2MNT);

        /* release cached inode/block bitmaps */
        for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++)
                if (fs->s_inode_bitmap[i])
                        ULCK_BUF(fs->s_inode_bitmap[i])

        for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++)
                if (fs->s_block_bitmap[i])
                        ULCK_BUF(fs->s_block_bitmap[i])

        ump->um_devvp->v_rdev->si_mountpoint = NULL;

        vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_CLOSE(ump->um_devvp, ronly ? FREAD : FREAD|FWRITE, NULL);
        vn_unlock(ump->um_devvp);

        vrele(ump->um_devvp);
        kfree(fs->s_es, M_EXT2MNT);
        kfree(fs, M_EXT2MNT);
        kfree(ump, M_EXT2MNT);
        mp->mnt_data = (qaddr_t)0;
        mp->mnt_flag &= ~MNT_LOCAL;
        return (error);
}

/*
 * Flush out all the files in a filesystem.
 */
static int
ext2_flushfiles(struct mount *mp, int flags)
{
        struct ext2_mount *ump;
        int error;
#ifdef QUOTA
        int i;
#endif

        ump = VFSTOEXT2(mp);
#ifdef QUOTA
        if (mp->mnt_flag & MNT_QUOTA) {
                if ((error = vflush(mp, 0, SKIPSYSTEM|flags)) != 0)
                        return (error);
                for (i = 0; i < MAXQUOTAS; i++) {
                        if (ump->um_quotas[i] == NULLVP)
                                continue;
                        ext2_quotaoff(mp, i);
                }
                /*
                 * Here we fall through to vflush again to ensure
                 * that we have gotten rid of all the system vnodes.
                 */
        }
#endif
        error = vflush(mp, 0, flags);
        return (error);
}

/*
 * 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 ext2_sync_scan(struct mount *mp, struct vnode *vp, void *data);

static int
ext2_sync(struct mount *mp, int waitfor)
{
        struct ext2_mount *ump = VFSTOEXT2(mp);
        struct ext2_sb_info *fs;
        struct scaninfo scaninfo;
        int error;

        fs = ump->um_e2fs;
        if (fs->s_dirt != 0 && fs->s_rd_only != 0) {            /* XXX */
                kprintf("fs = %s\n", fs->fs_fsmnt);
                panic("ext2_sync: rofs mod");
        }

        /*
         * Write back each (modified) inode.
         */
        scaninfo.allerror = 0;
        scaninfo.rescan = 1;
        scaninfo.waitfor = waitfor;
        while (scaninfo.rescan) {
                scaninfo.rescan = 0;
                vmntvnodescan(mp, VMSC_GETVP|VMSC_NOWAIT,
                              NULL, ext2_sync_scan, &scaninfo);
        }

        /*
         * Force stale file system control information to be flushed.
         */
        if ((waitfor & MNT_LAZY) == 0) {
                vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
                if ((error = VOP_FSYNC(ump->um_devvp, waitfor, 0)) != 0)
                        scaninfo.allerror = error;
                vn_unlock(ump->um_devvp);
        }
#ifdef QUOTA
        ext2_qsync(mp);
#endif
        /*
         * Write back modified superblock.
         */
        if (fs->s_dirt != 0) {
                fs->s_dirt = 0;
                fs->s_es->s_wtime = time_second;
                if ((error = ext2_sbupdate(ump, waitfor)) != 0)
                        scaninfo.allerror = error;
        }
        return (scaninfo.allerror);
}

static int
ext2_sync_scan(struct mount *mp, struct vnode *vp, void *data)
{
        struct scaninfo *info = data;
        struct inode *ip;
        int error;

        ip = VTOI(vp);
        if (vp->v_type == VNON ||
            ((ip->i_flag &
            (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0 &&
            (RB_EMPTY(&vp->v_rbdirty_tree) || (info->waitfor & MNT_LAZY)))) {
                return(0);
        }
        if ((error = VOP_FSYNC(vp, info->waitfor, 0)) != 0)
                info->allerror = error;
        return(0);
}

/*
 * 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.
 */
static int
ext2_vget(struct mount *mp, struct vnode *dvp, ino_t ino, struct vnode **vpp)
{
        struct ext2_sb_info *fs;
        struct inode *ip;
        struct ext2_mount *ump;
        struct buf *bp;
        struct vnode *vp;
        cdev_t dev;
        int i, error;
        int used_blocks;

        ump = VFSTOEXT2(mp);
        dev = ump->um_dev;
restart:
        if ((*vpp = ext2_ihashget(dev, ino)) != NULL)
                return (0);

        /*
         * Lock out the creation of new entries in the FFS hash table in
         * case getnewvnode() or MALLOC() blocks, otherwise a duplicate
         * may occur!
         */
        if (ext2fs_inode_hash_lock) {
                while (ext2fs_inode_hash_lock) {
                        ext2fs_inode_hash_lock = -1;
                        tsleep(&ext2fs_inode_hash_lock, 0, "e2vget", 0);
                }
                goto restart;
        }
        ext2fs_inode_hash_lock = 1;

        /*
         * If this MALLOC() is performed after the getnewvnode()
         * it might block, leaving a vnode with a NULL v_data to be
         * found by ext2_sync() if a sync happens to fire right then,
         * which will cause a panic because ext2_sync() blindly
         * dereferences vp->v_data (as well it should).
         */
        ip = kmalloc(sizeof(struct inode), M_EXT2NODE, M_WAITOK);

        /* Allocate a new vnode/inode. */
        if ((error = getnewvnode(VT_EXT2FS, mp, &vp, 0, LK_CANRECURSE)) != 0) {
                if (ext2fs_inode_hash_lock < 0)
                        wakeup(&ext2fs_inode_hash_lock);
                ext2fs_inode_hash_lock = 0;
                *vpp = NULL;
                kfree(ip, M_EXT2NODE);
                return (error);
        }
        bzero((caddr_t)ip, sizeof(struct inode));
        vp->v_data = ip;
        ip->i_vnode = vp;
        ip->i_e2fs = fs = ump->um_e2fs;
        ip->i_dev = dev;
        ip->i_number = ino;
#ifdef QUOTA
        for (i = 0; i < MAXQUOTAS; i++)
                ip->i_dquot[i] = NODQUOT;
#endif
        /*
         * Put it onto its hash chain.  Since our vnode is locked, 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.
         */
        ext2_ihashins(ip);

        if (ext2fs_inode_hash_lock < 0)
                wakeup(&ext2fs_inode_hash_lock);
        ext2fs_inode_hash_lock = 0;

        /* Read in the disk contents for the inode, copy into the inode. */
#if 0
kprintf("ext2_vget(%d) dbn= %d ", ino, fsbtodb(fs, ino_to_fsba(fs, ino)));
#endif
        error = bread(ump->um_devvp, fsbtodoff(fs, ino_to_fsba(fs, ino)),
                      (int)fs->s_blocksize, &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);
                vx_put(vp);
                *vpp = NULL;
                return (error);
        }
        /* convert ext2 inode to dinode */
        ext2_ei2di((struct ext2_inode *) ((char *)bp->b_data + EXT2_INODE_SIZE(fs) *
                        ino_to_fsbo(fs, ino)), &ip->i_din);
        ip->i_block_group = ino_to_cg(fs, ino);
        ip->i_next_alloc_block = 0;
        ip->i_next_alloc_goal = 0;
        ip->i_prealloc_count = 0;
        ip->i_prealloc_block = 0;
        /* now we want to make sure that block pointers for unused
           blocks are zeroed out - ext2_balloc depends on this
           although for regular files and directories only
        */
        if(S_ISDIR(ip->i_mode) || S_ISREG(ip->i_mode)) {
                used_blocks = (ip->i_size+fs->s_blocksize-1) / fs->s_blocksize;
                for(i = used_blocks; i < EXT2_NDIR_BLOCKS; i++)
                        ip->i_db[i] = 0;
        }
#if 0
        ext2_print_inode(ip);
#endif
        bqrelse(bp);

        /*
         * Initialize the vnode from the inode, check for aliases.
         * Note that the underlying vnode may have changed.
         */
        if ((error = ext2_vinit(mp, &vp)) != 0) {
                vx_put(vp);
                *vpp = NULL;
                return (error);
        }

        /*
         * Finish inode initialization now that aliasing has been resolved.
         */
        ip->i_devvp = ump->um_devvp;
        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_gen == 0) {
                ip->i_gen = krandom() / 2 + 1;
                if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0)
                        ip->i_flag |= IN_MODIFIED;
        }
        /*
         * Return the locked and refd vnode.
         */
        *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 ext2_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
ext2_fhtovp(struct mount *mp, struct vnode *rootvp,
            struct fid *fhp, struct vnode **vpp)
{
        struct ufid *ufhp;
        struct ext2_sb_info *fs;
        struct inode *ip;
        struct vnode *nvp;
        int error;

        ufhp = (struct ufid *)fhp;
        fs = VFSTOEXT2(mp)->um_e2fs;
        if (ufhp->ufid_ino < EXT2_ROOTINO ||
            ufhp->ufid_ino > fs->s_groups_count * fs->s_es->s_inodes_per_group)
                return (ESTALE);

        error = VFS_VGET(mp, rootvp, ufhp->ufid_ino, &nvp);
        if (error) {
                *vpp = NULLVP;
                return (error);
        }
        ip = VTOI(nvp);
        if (ip->i_mode == 0 ||
            ip->i_gen != ufhp->ufid_gen ||
            (VFSTOEXT2(mp)->um_i_effnlink_valid ? ip->i_effnlink :
            ip->i_nlink) <= 0) {
                vput(nvp);
                *vpp = NULLVP;
                return (ESTALE);
        }
        *vpp = nvp;
        return (0);
}

/*
 * Vnode pointer to File handle
 */
/* ARGSUSED */
static int
ext2_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_gen;
        return (0);
}

/*
 * This is the generic part of fhtovp called after the underlying
 * filesystem has validated the file handle.
 *
 * Verify that a host should have access to a filesystem.
 */
int
ext2_check_export(struct mount *mp, struct sockaddr *nam, int *exflagsp,
                 struct ucred **credanonp)
{
        struct netcred *np;
        struct ext2_mount *ump;

        ump = VFSTOEXT2(mp);
        /*
         * Get the export permission structure for this <mp, client> tuple.
         */
        np = vfs_export_lookup(mp, &ump->um_export, nam);
        if (np == NULL)
                return (EACCES);

        *exflagsp = np->netc_exflags;
        *credanonp = &np->netc_anon;
        return (0);
}

/*
 * Write a superblock and associated information back to disk.
 */
static int
ext2_sbupdate(struct ext2_mount *mp, int waitfor)
{
        struct ext2_sb_info *fs = mp->um_e2fs;
        struct ext2_super_block *es = fs->s_es;
        struct buf *bp;
        int error = 0;
/*
kprintf("\nupdating superblock, waitfor=%s\n", waitfor == MNT_WAIT ? "yes":"no");
*/
        bp = getblk(mp->um_devvp, SBOFF, SBSIZE, 0, 0);
        bcopy((caddr_t)es, bp->b_data, (u_int)sizeof(struct ext2_super_block));
        if (waitfor == MNT_WAIT)
                error = bwrite(bp);
        else
                bawrite(bp);

        /*
         * The buffers for group descriptors, inode bitmaps and block bitmaps
         * are not busy at this point and are (hopefully) written by the
         * usual sync mechanism. No need to write them here
         */

        return (error);
}