/*      $NetBSD: filecore_vfsops.c,v 1.83 2020/03/16 21:20:10 pgoyette Exp $    */

/*-
 * Copyright (c) 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.
 *
 *      filecore_vfsops.c       1.1     1998/6/26
 */

/*-
 * Copyright (c) 1998 Andrew McMurry
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 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.
 *
 *      filecore_vfsops.c       1.1     1998/6/26
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: filecore_vfsops.c,v 1.83 2020/03/16 21:20:10 pgoyette Exp $");

#if defined(_KERNEL_OPT)
#include "opt_compat_netbsd.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/specfs/specdev.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/file.h>
#include <sys/device.h>
#include <sys/errno.h>
#include <sys/pool.h>
#include <sys/conf.h>
#include <sys/sysctl.h>
#include <sys/kauth.h>
#include <sys/module.h>

#include <fs/filecorefs/filecore.h>
#include <fs/filecorefs/filecore_extern.h>
#include <fs/filecorefs/filecore_node.h>
#include <fs/filecorefs/filecore_mount.h>

MODULE(MODULE_CLASS_VFS, filecore, NULL);

extern const struct vnodeopv_desc filecore_vnodeop_opv_desc;

const struct vnodeopv_desc * const filecore_vnodeopv_descs[] = {
        &filecore_vnodeop_opv_desc,
        NULL,
};

struct vfsops filecore_vfsops = {
        .vfs_name = MOUNT_FILECORE,
        .vfs_min_mount_data = sizeof (struct filecore_args),
        .vfs_mount = filecore_mount,
        .vfs_start = filecore_start,
        .vfs_unmount = filecore_unmount,
        .vfs_root = filecore_root,
        .vfs_quotactl = (void *)eopnotsupp,
        .vfs_statvfs = filecore_statvfs,
        .vfs_sync = filecore_sync,
        .vfs_vget = filecore_vget,
        .vfs_loadvnode = filecore_loadvnode,
        .vfs_fhtovp = filecore_fhtovp,
        .vfs_vptofh = filecore_vptofh,
        .vfs_init = filecore_init,
        .vfs_reinit = filecore_reinit,
        .vfs_done = filecore_done,
        .vfs_snapshot = (void *)eopnotsupp,
        .vfs_extattrctl = vfs_stdextattrctl,
        .vfs_suspendctl = genfs_suspendctl,
        .vfs_renamelock_enter = genfs_renamelock_enter,
        .vfs_renamelock_exit = genfs_renamelock_exit,
        .vfs_fsync = (void *)eopnotsupp,
        .vfs_opv_descs = filecore_vnodeopv_descs
};

SYSCTL_SETUP(filecore_sysctl_setup, "filecore fs sysctl")
{

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "filecore",
                       SYSCTL_DESCR("Acorn FILECORE file system"),
                       NULL, 0, NULL, 0,
                       CTL_VFS, 19, CTL_EOL);
        /*
         * XXX the "19" above could be dynamic, thereby eliminating
         * one more instance of the "number to vfs" mapping problem,
         * but "19" is the order as taken from sys/mount.h
         */
}

static int
filecore_modcmd(modcmd_t cmd, void *arg)
{
        int error;

        switch (cmd) {
        case MODULE_CMD_INIT:
                error = vfs_attach(&filecore_vfsops);
                if (error != 0)
                        break;
                break;
        case MODULE_CMD_FINI:
                error = vfs_detach(&filecore_vfsops);
                if (error != 0)
                        break;
                break;
        default:
                error = ENOTTY;
                break;
        }

        return (error);
}

/*
 * Called by vfs_mountroot when iso is going to be mounted as root.
 *
 * Name is updated by mount(8) after booting.
 */

static int filecore_mountfs(struct vnode *devvp, struct mount *mp,
                struct lwp *l, struct filecore_args *argp);

#if 0
int
filecore_mountroot(void)
{
        struct mount *mp;
        extern struct vnode *rootvp;
        struct proc *p = curproc;       /* XXX */
        int error;
        struct filecore_args args;

        if (device_class(root_device) != DV_DISK)
                return (ENODEV);

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

        if ((error = vfs_rootmountalloc(MOUNT_FILECORE, "root_device", &mp)) != 0)
                return (error);

        args.flags = FILECOREMNT_ROOT;
        if ((error = filecore_mountfs(rootvp, mp, p, &args)) != 0) {
                vfs_unbusy(mp);
                vfs_rele(mp);
                return (error);
        }
        mountlist_append(mp);
        (void)filecore_statvfs(mp, &mp->mnt_stat, p);
        vfs_unbusy(mp);
        return (0);
}
#endif

/*
 * VFS Operations.
 *
 * mount system call
 */
int
filecore_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
{
        struct lwp *l = curlwp;
        struct vnode *devvp;
        struct filecore_args *args = data;
        int error;
        struct filecore_mnt *fcmp = NULL;

        if (args == NULL)
                return EINVAL;
        if (*data_len < sizeof *args)
                return EINVAL;

        if (mp->mnt_flag & MNT_GETARGS) {
                fcmp = VFSTOFILECORE(mp);
                if (fcmp == NULL)
                        return EIO;
                args->flags = fcmp->fc_mntflags;
                args->uid = fcmp->fc_uid;
                args->gid = fcmp->fc_gid;
                args->fspec = NULL;
                *data_len = sizeof *args;
                return 0;
        }

        if ((mp->mnt_flag & MNT_RDONLY) == 0)
                return (EROFS);

        if ((mp->mnt_flag & MNT_UPDATE) && args->fspec == NULL)
                return EINVAL;

        /*
         * Not an update, or updating the name: look up the name
         * and verify that it refers to a sensible block device.
         */
        error = namei_simple_user(args->fspec,
                                NSM_FOLLOW_NOEMULROOT, &devvp);
        if (error != 0)
                return (error);

        if (devvp->v_type != VBLK) {
                vrele(devvp);
                return ENOTBLK;
        }
        if (bdevsw_lookup(devvp->v_rdev) == NULL) {
                vrele(devvp);
                return ENXIO;
        }
        /*
         * If mount by non-root, then verify that user has necessary
         * permissions on the device.
         */
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
            KAUTH_REQ_SYSTEM_MOUNT_DEVICE, mp, devvp, KAUTH_ARG(VREAD));
        VOP_UNLOCK(devvp);
        if (error) {
                vrele(devvp);
                return (error);
        }
        if ((mp->mnt_flag & MNT_UPDATE) == 0)
                error = filecore_mountfs(devvp, mp, l, args);
        else {
                fcmp = VFSTOFILECORE(mp);
                if (devvp != fcmp->fc_devvp)
                        error = EINVAL; /* needs translation */
                else
                        vrele(devvp);
        }
        if (error) {
                vrele(devvp);
                return error;
        }
        fcmp = VFSTOFILECORE(mp);
        return set_statvfs_info(path, UIO_USERSPACE, args->fspec, UIO_USERSPACE,
            mp->mnt_op->vfs_name, mp, l);
}

/*
 * Common code for mount and mountroot
 */
static int
filecore_mountfs(struct vnode *devvp, struct mount *mp, struct lwp *l, struct filecore_args *argp)
{
        struct filecore_mnt *fcmp = (struct filecore_mnt *)0;
        struct buf *bp = NULL;
        dev_t dev = devvp->v_rdev;
        int error = EINVAL;
        int ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
        struct filecore_disc_record *fcdr;
        unsigned map;
        unsigned log2secsize;

        if (!ronly)
                return EROFS;

        if ((error = vinvalbuf(devvp, V_SAVE, l->l_cred, l, 0, 0)) != 0)
                return (error);

        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED);
        VOP_UNLOCK(devvp);
        if (error)
                return error;

        /* Read the filecore boot block to check FS validity and to find the map */
        error = bread(devvp, FILECORE_BOOTBLOCK_BLKN,
                           FILECORE_BOOTBLOCK_SIZE, 0, &bp);
#ifdef FILECORE_DEBUG_BR
                printf("bread(%p, %x, %d, CRED, %p)=%d\n", devvp,
                       FILECORE_BOOTBLOCK_BLKN, FILECORE_BOOTBLOCK_SIZE,
                       bp, error);
#endif
        if (error != 0)
                goto out;

        KASSERT(bp != NULL);
        if (filecore_bbchecksum(bp->b_data) != 0) {
                error = EINVAL;
                goto out;
        }
        fcdr = (struct filecore_disc_record *)((char *)(bp->b_data) +
            FILECORE_BB_DISCREC);
        map = ((((8 << fcdr->log2secsize) - fcdr->zone_spare)
            * (fcdr->nzones / 2) - 8 * FILECORE_DISCREC_SIZE)
            << fcdr->log2bpmb) >> fcdr->log2secsize;
        log2secsize = fcdr->log2secsize;
#ifdef FILECORE_DEBUG_BR
        printf("brelse(%p) vf1\n", bp);
#endif
        brelse(bp, BC_AGE);
        bp = NULL;

        /* Read the bootblock in the map */
        error = bread(devvp, map, 1 << log2secsize, 0, &bp);
#ifdef FILECORE_DEBUG_BR
                printf("bread(%p, %x, %d, CRED, %p)=%d\n", devvp,
                       map, 1 << log2secsize, bp, error);
#endif
        if (error != 0)
                goto out;
        fcdr = (struct filecore_disc_record *)((char *)(bp->b_data) + 4);
        fcmp = kmem_zalloc(sizeof(*fcmp), KM_SLEEP);
        if (fcdr->log2bpmb > fcdr->log2secsize)
                fcmp->log2bsize = fcdr->log2bpmb;
        else    fcmp->log2bsize = fcdr->log2secsize;
        fcmp->blksize = 1 << fcmp->log2bsize;
        memcpy(&fcmp->drec, fcdr, sizeof(*fcdr));
        fcmp->map = map;
        fcmp->idspz = ((8 << fcdr->log2secsize) - fcdr->zone_spare)
            / (fcdr->idlen + 1);
        fcmp->mask = (1 << fcdr->idlen) - 1;
        if (fcdr->big_flag & 1) {
                fcmp->nblks = ((((u_int64_t)fcdr->disc_size_2) << 32)
                    + fcdr->disc_size) / fcmp->blksize;
        } else {
                fcmp->nblks=fcdr->disc_size / fcmp->blksize;
        }

#ifdef FILECORE_DEBUG_BR
        printf("brelse(%p) vf2\n", bp);
#endif
        brelse(bp, BC_AGE);
        bp = NULL;

        mp->mnt_data = fcmp;
        mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev;
        mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_FILECORE);
        mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
        mp->mnt_stat.f_namemax = 10;
        mp->mnt_flag |= MNT_LOCAL;
        mp->mnt_dev_bshift = fcdr->log2secsize;
        mp->mnt_fs_bshift = fcmp->log2bsize;

        fcmp->fc_mountp = mp;
        fcmp->fc_dev = dev;
        fcmp->fc_devvp = devvp;
        fcmp->fc_mntflags = argp->flags;
        if (argp->flags & FILECOREMNT_USEUID) {
                fcmp->fc_uid = kauth_cred_getuid(l->l_cred);
                fcmp->fc_gid = kauth_cred_getgid(l->l_cred);
        } else {
                fcmp->fc_uid = argp->uid;
                fcmp->fc_gid = argp->gid;
        }

        return 0;
out:
        if (bp) {
#ifdef FILECORE_DEBUG_BR
                printf("brelse(%p) vf3\n", bp);
#endif
                brelse(bp, 0);
        }
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        (void)VOP_CLOSE(devvp, ronly ? FREAD : FREAD|FWRITE, NOCRED);
        VOP_UNLOCK(devvp);
        return error;
}

/*
 * Make a filesystem operational.
 * Nothing to do at the moment.
 */
/* ARGSUSED */
int
filecore_start(struct mount *mp, int flags)
{
        return 0;
}

/*
 * unmount system call
 */
int
filecore_unmount(struct mount *mp, int mntflags)
{
        struct filecore_mnt *fcmp;
        int error, flags = 0;

        if (mntflags & MNT_FORCE)
                flags |= FORCECLOSE;
        if ((error = vflush(mp, NULLVP, flags)) != 0)
                return (error);

        fcmp = VFSTOFILECORE(mp);

        if (fcmp->fc_devvp->v_type != VBAD)
                spec_node_setmountedfs(fcmp->fc_devvp, NULL);
        vn_lock(fcmp->fc_devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_CLOSE(fcmp->fc_devvp, FREAD, NOCRED);
        vput(fcmp->fc_devvp);
        kmem_free(fcmp, sizeof(*fcmp));
        mp->mnt_data = NULL;
        mp->mnt_flag &= ~MNT_LOCAL;
        return (error);
}

/*
 * Return root of a filesystem
 */
int
filecore_root(struct mount *mp, int lktype, struct vnode **vpp)
{
        struct vnode *nvp;
        int error;

        if ((error = VFS_VGET(mp, FILECORE_ROOTINO, lktype, &nvp)) != 0)
                return (error);
        *vpp = nvp;
        return (0);
}

/*
 * Get file system statistics.
 */
int
filecore_statvfs(struct mount *mp, struct statvfs *sbp)
{
        struct filecore_mnt *fcmp = VFSTOFILECORE(mp);

        sbp->f_bsize = fcmp->blksize;
        sbp->f_frsize = sbp->f_bsize; /* XXX */
        sbp->f_iosize = sbp->f_bsize;   /* XXX */
        sbp->f_blocks = fcmp->nblks;
        sbp->f_bfree = 0; /* total free blocks */
        sbp->f_bavail = 0; /* blocks free for non superuser */
        sbp->f_bresvd = 0; /* reserved blocks */
        sbp->f_files =  0; /* total files */
        sbp->f_ffree = 0; /* free file nodes for non superuser */
        sbp->f_favail = 0; /* free file nodes */
        sbp->f_fresvd = 0; /* reserved file nodes */
        copy_statvfs_info(sbp, mp);
        return 0;
}

/* ARGSUSED */
int
filecore_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
{
        return (0);
}

/*
 * File handle to vnode
 *
 * Have to be really careful about stale file handles:
 * - check that the inode number is in range
 * - call iget() to get the locked inode
 * - check for an unallocated inode (i_mode == 0)
 * - check that the generation number matches
 */

struct ifid {
        ushort          ifid_len;
        ushort          ifid_pad;
        u_int32_t       ifid_ino;
};

/* ARGSUSED */
int
filecore_fhtovp(struct mount *mp, struct fid *fhp, int lktype,
    struct vnode **vpp)
{
        struct ifid ifh;
        struct vnode *nvp;
        struct filecore_node *ip;
        int error;

        if (fhp->fid_len != sizeof(struct ifid))
                return EINVAL;

        memcpy(&ifh, fhp, sizeof(ifh));
        if ((error = VFS_VGET(mp, ifh.ifid_ino, lktype, &nvp)) != 0) {
                *vpp = NULLVP;
                return (error);
        }
        ip = VTOI(nvp);
        if (filecore_staleinode(ip)) {
                vput(nvp);
                *vpp = NULLVP;
                return (ESTALE);
        }
        *vpp = nvp;
        return (0);
}

/* This looks complicated. Look at other vgets as well as the iso9660 one.
 *
 * The filecore inode number is made up of 1 byte directory entry index and
 * 3 bytes of the internal disc address of the directory. On a read-only
 * filesystem this is unique. For a read-write version we may not be able to
 * do vget, see msdosfs.
 */

int
filecore_vget(struct mount *mp, ino_t ino, int lktype, struct vnode **vpp)
{
        int error;

        error = vcache_get(mp, &ino, sizeof(ino), vpp);
        if (error)
                return error;
        error = vn_lock(*vpp, lktype);
        if (error) {
                vrele(*vpp);
                *vpp = NULL;
                return error;
        }
        return 0;
}

/*
 * Vnode pointer to File handle
 */
/* ARGSUSED */
int
filecore_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
{
        struct filecore_node *ip = VTOI(vp);
        struct ifid ifh;

        if (*fh_size < sizeof(struct ifid)) {
                *fh_size = sizeof(struct ifid);
                return E2BIG;
        }
        memset(&ifh, 0, sizeof(ifh));
        ifh.ifid_len = sizeof(struct ifid);
        ifh.ifid_ino = ip->i_number;
        memcpy(fhp, &ifh, sizeof(ifh));
        return 0;
}