/*      $NetBSD: sysvbfs_vfsops.c,v 1.48 2022/05/03 07:34:38 hannken Exp $      */

/*-
 * Copyright (c) 2004 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by UCHIYAMA Yasushi.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sysvbfs_vfsops.c,v 1.48 2022/05/03 07:34:38 hannken Exp $");

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/pool.h>
#include <sys/time.h>
#include <sys/ucred.h>
#include <sys/mount.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/kauth.h>
#include <sys/proc.h>

/* v-node */
#include <sys/namei.h>
#include <sys/vnode.h>
/* devsw */
#include <sys/conf.h>

#include <fs/sysvbfs/sysvbfs.h> /* external interface */
#include <fs/sysvbfs/bfs.h>     /* internal interface */

#ifdef SYSVBFS_VNOPS_DEBUG
#define DPRINTF(fmt, args...)   printf(fmt, ##args)
#else
#define DPRINTF(arg...)         ((void)0)
#endif

MALLOC_JUSTDEFINE(M_SYSVBFS_VFS, "sysvbfs vfs", "sysvbfs vfs structures");

struct pool sysvbfs_node_pool;

int sysvbfs_mountfs(struct vnode *, struct mount *, struct lwp *);

int
sysvbfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
{
        struct lwp *l = curlwp;
        struct sysvbfs_args *args = data;
        struct sysvbfs_mount *bmp = NULL;
        struct vnode *devvp = NULL;
        int error = 0;
        bool update;

        DPRINTF("%s: mnt_flag=%x\n", __func__, mp->mnt_flag);

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

        if (mp->mnt_flag & MNT_GETARGS) {
                if ((bmp = (struct sysvbfs_mount *)mp->mnt_data) == NULL)
                        return EIO;
                args->fspec = NULL;
                *data_len = sizeof *args;
                return 0;
        }


        DPRINTF("%s: args->fspec=%s\n", __func__, args->fspec);
        update = mp->mnt_flag & MNT_UPDATE;
        if (args->fspec == NULL) {
                /* nothing to do. */
                return EINVAL;
        }

        if (args->fspec != NULL) {
                /* Look up the name and verify that it's sane. */
                error = namei_simple_user(args->fspec,
                                        NSM_FOLLOW_NOEMULROOT, &devvp);
                if (error != 0)
                        return (error);

                if (!update) {
                        /*
                         * Be sure this is a valid block device
                         */
                        if (devvp->v_type != VBLK)
                                error = ENOTBLK;
                        else if (bdevsw_lookup(devvp->v_rdev) == NULL)
                                error = ENXIO;
                } else {
                        /*
                         * Be sure we're still naming the same device
                         * used for our initial mount
                         */
                        bmp = (struct sysvbfs_mount *)mp->mnt_data;
                        if (devvp != bmp->devvp)
                                error = EINVAL;
                }
        }

        /*
         * If mount by non-root, then verify that user has necessary
         * permissions on the device.
         *
         * Permission to update a mount is checked higher, so here we presume
         * updating the mount is okay (for example, as far as securelevel goes)
         * which leaves us with the normal check.
         */
        if (error == 0) {
                int accessmode = VREAD;
                if (update ?
                    (mp->mnt_iflag & IMNT_WANTRDWR) != 0 :
                    (mp->mnt_flag & MNT_RDONLY) == 0)
                        accessmode |= VWRITE;

                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(accessmode));
                VOP_UNLOCK(devvp);
        }

        if (error) {
                vrele(devvp);
                return error;
        }

        if (!update) {
                if ((error = sysvbfs_mountfs(devvp, mp, l)) != 0) {
                        vrele(devvp);
                        return error;
                }
        } else  if (mp->mnt_flag & MNT_RDONLY) {
                /* XXX: r/w -> read only */
        }

        return set_statvfs_info(path, UIO_USERSPACE, args->fspec, UIO_USERSPACE,
            mp->mnt_op->vfs_name, mp, l);
}

int
sysvbfs_mountfs(struct vnode *devvp, struct mount *mp, struct lwp *l)
{
        kauth_cred_t cred = l->l_cred;
        struct sysvbfs_mount *bmp;
        int error, oflags;

        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = vinvalbuf(devvp, V_SAVE, cred, l, 0, 0);
        if (error)
                goto out;

        /* Open block device */
        oflags = FREAD;
        if ((mp->mnt_flag & MNT_RDONLY) == 0)
                oflags |= FWRITE;
        if ((error = VOP_OPEN(devvp, oflags, NOCRED)) != 0)
                goto out;

        bmp = malloc(sizeof(*bmp), M_SYSVBFS_VFS, M_WAITOK | M_ZERO);
        bmp->devvp = devvp;
        bmp->mountp = mp;
        if ((error = sysvbfs_bfs_init(&bmp->bfs, devvp)) != 0) {
                free(bmp, M_SYSVBFS_VFS);
                VOP_CLOSE(devvp, oflags, NOCRED);
                goto out;
        }

        mp->mnt_data = bmp;
        mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)devvp->v_rdev;
        mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_SYSVBFS);
        mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
        mp->mnt_stat.f_namemax = BFS_FILENAME_MAXLEN;
        mp->mnt_flag |= MNT_LOCAL;
        mp->mnt_dev_bshift = BFS_BSHIFT;
        mp->mnt_fs_bshift = BFS_BSHIFT;

 out:
        VOP_UNLOCK(devvp);
        return error;
}

int
sysvbfs_start(struct mount *mp, int flags)
{

        DPRINTF("%s:\n", __func__);
        /* Nothing to do. */
        return 0;
}

int
sysvbfs_unmount(struct mount *mp, int mntflags)
{
        struct sysvbfs_mount *bmp = (void *)mp->mnt_data;
        int error;

        DPRINTF("%s: %p\n", __func__, bmp);

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

        vn_lock(bmp->devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_CLOSE(bmp->devvp, FREAD, NOCRED);
        vput(bmp->devvp);

        sysvbfs_bfs_fini(bmp->bfs);

        free(bmp, M_SYSVBFS_VFS);
        mp->mnt_data = NULL;
        mp->mnt_flag &= ~MNT_LOCAL;

        return 0;
}

int
sysvbfs_root(struct mount *mp, int lktype, struct vnode **vpp)
{
        struct vnode *vp;
        int error;

        DPRINTF("%s:\n", __func__);
        if ((error = VFS_VGET(mp, BFS_ROOT_INODE, lktype, &vp)) != 0)
                return error;
        *vpp = vp;

        return 0;
}

int
sysvbfs_statvfs(struct mount *mp, struct statvfs *f)
{
        struct sysvbfs_mount *bmp = mp->mnt_data;
        struct bfs *bfs = bmp->bfs;
        int free_block;
        size_t data_block;

        data_block = (bfs->data_end - bfs->data_start) >> BFS_BSHIFT;
        if (bfs_inode_alloc(bfs, 0, 0, &free_block) != 0)
                free_block = 0;
        else
                free_block = (bfs->data_end >> BFS_BSHIFT) - free_block;

        DPRINTF("%s: %d %d %d\n", __func__, bfs->data_start,
            bfs->data_end, free_block);

        f->f_bsize = BFS_BSIZE;
        f->f_frsize = BFS_BSIZE;
        f->f_iosize = BFS_BSIZE;
        f->f_blocks = data_block;
        f->f_bfree = free_block;
        f->f_bavail = f->f_bfree;
        f->f_bresvd = 0;
        f->f_files = bfs->max_inode;
        f->f_ffree = bfs->max_inode - bfs->n_inode;
        f->f_favail = f->f_ffree;
        f->f_fresvd = 0;
        copy_statvfs_info(f, mp);

        return 0;
}

int
sysvbfs_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
{
        struct vnode_iterator *marker;
        struct vnode *vp;
        int err, error;

        DPRINTF("%s:\n", __func__);
        error = 0;
        vfs_vnode_iterator_init(mp, &marker);
        while ((vp = vfs_vnode_iterator_next(marker, NULL, NULL)) != NULL) {
                err = vn_lock(vp, LK_EXCLUSIVE);
                if (err) {
                        vrele(vp);
                        continue;
                }
                err = VOP_FSYNC(vp, cred, FSYNC_WAIT, 0, 0);
                vput(vp);
                if (err != 0)
                        error = err;
        }
        vfs_vnode_iterator_destroy(marker);

        return error;
}

int
sysvbfs_loadvnode(struct mount *mp, struct vnode *vp,
    const void *key, size_t key_len, const void **new_key)
{
        struct sysvbfs_mount *bmp;
        struct bfs *bfs;
        struct sysvbfs_node *bnode;
        struct bfs_inode *inode;
        uint16_t ino;

        KASSERT(key_len == sizeof(ino));
        memcpy(&ino, key, key_len);

        DPRINTF("%s: i-node=%u\n", __func__, ino);

        bmp = mp->mnt_data;
        bfs = bmp->bfs;

        /* Lookup requested i-node */
        if (!bfs_inode_lookup(bfs, ino, &inode)) {
                DPRINTF("%s: bfs_inode_lookup failed.\n", __func__);
                return ENOENT;
        }

        bnode = pool_get(&sysvbfs_node_pool, PR_WAITOK);
        memset(bnode, 0, sizeof(*bnode));

        vp->v_tag = VT_SYSVBFS;
        vp->v_op = sysvbfs_vnodeop_p;
        vp->v_data = bnode;
        if (ino == BFS_ROOT_INODE) {    /* BFS is flat filesystem */
                vp->v_type = VDIR;
                vp->v_vflag |= VV_ROOT;
        } else {
                vp->v_type = VREG;
        }

        bnode->vnode = vp;
        bnode->bmp = bmp;
        bnode->inode = inode;
        bnode->lockf = NULL; /* advlock */

        genfs_node_init(vp, &sysvbfs_genfsops);
        uvm_vnp_setsize(vp, bfs_file_size(inode));

        *new_key = &bnode->inode->number;

        return 0;
}

int
sysvbfs_vget(struct mount *mp, ino_t ino, int lktype, struct vnode **vpp)
{
        int error;
        uint16_t number;
        struct vnode *vp;

        KASSERT(ino <= UINT16_MAX);
        number = ino;

        DPRINTF("%s: i-node=%u\n", __func__, number);

        error = vcache_get(mp, &number, sizeof(number), &vp);
        if (error)
                return error;
        error = vn_lock(vp, lktype);
        if (error) {
                vrele(vp);
                return error;
        }

        *vpp = vp;

        return 0;
}

int
sysvbfs_fhtovp(struct mount *mp, struct fid *fid, int lktype,
    struct vnode **vpp)
{

        DPRINTF("%s:\n", __func__);
        /* notyet */
        return EOPNOTSUPP;
}

int
sysvbfs_vptofh(struct vnode *vpp, struct fid *fid, size_t *fh_size)
{

        DPRINTF("%s:\n", __func__);
        /* notyet */
        return EOPNOTSUPP;
}

MALLOC_DECLARE(M_BFS);
MALLOC_DECLARE(M_SYSVBFS_VNODE);

void
sysvbfs_init(void)
{

        DPRINTF("%s:\n", __func__);
        malloc_type_attach(M_SYSVBFS_VFS);
        malloc_type_attach(M_BFS);
        malloc_type_attach(M_SYSVBFS_VNODE);
        pool_init(&sysvbfs_node_pool, sizeof(struct sysvbfs_node), 0, 0, 0,
            "sysvbfs_node_pool", &pool_allocator_nointr, IPL_NONE);
}

void
sysvbfs_reinit(void)
{

        /* Nothing to do. */
        DPRINTF("%s:\n", __func__);
}

void
sysvbfs_done(void)
{

        DPRINTF("%s:\n", __func__);
        pool_destroy(&sysvbfs_node_pool);
        malloc_type_detach(M_BFS);
        malloc_type_detach(M_SYSVBFS_VFS);
        malloc_type_detach(M_SYSVBFS_VNODE);
}

int
sysvbfs_gop_alloc(struct vnode *vp, off_t off, off_t len, int flags,
    kauth_cred_t cred)
{

        return 0;
}