/*      $NetBSD: v7fs_vfsops.c,v 1.19 2022/05/03 07:34:38 hannken Exp $ */

/*-
 * Copyright (c) 2004, 2011 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: v7fs_vfsops.c,v 1.19 2022/05/03 07:34:38 hannken Exp $");
#if defined _KERNEL_OPT
#include "opt_v7fs.h"
#endif

#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/disk.h>
#include <sys/device.h>
#include <sys/fcntl.h>
#include <sys/kmem.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 "v7fs_extern.h"
#include "v7fs.h"
#include "v7fs_impl.h"
#include "v7fs_inode.h"
#include "v7fs_superblock.h"

#ifdef V7FS_VFSOPS_DEBUG
#define DPRINTF(fmt, args...)   printf("%s: " fmt, __func__, ##args)
#else
#define DPRINTF(arg...)         ((void)0)
#endif

struct pool v7fs_node_pool;

static int v7fs_mountfs(struct vnode *, struct mount *, int);
static int v7fs_openfs(struct vnode *, struct mount *, struct lwp *);
static void v7fs_closefs(struct vnode *, struct mount *);
static int is_v7fs_partition(struct vnode *);
static enum vtype v7fs_mode_to_vtype(v7fs_mode_t mode);

int
v7fs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
{
        struct lwp *l = curlwp;
        struct v7fs_args *args = data;
        struct v7fs_mount *v7fsmount = (void *)mp->mnt_data;
        struct vnode *devvp = NULL;
        int error = 0;
        bool update = mp->mnt_flag & MNT_UPDATE;

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

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

        if (mp->mnt_flag & MNT_GETARGS) {
                if (!v7fsmount)
                        return EIO;
                args->fspec = NULL;
                args->endian = v7fsmount->core->endian;
                *data_len = sizeof(*args);
                return 0;
        }

        DPRINTF("args->fspec=%s endian=%d\n", args->fspec, args->endian);
        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);
                DPRINTF("mount device=%lx\n", (long)devvp->v_rdev);

                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 {
                        KDASSERT(v7fsmount);
                        /*
                         * Be sure we're still naming the same device
                         * used for our initial mount
                         */
                        if (devvp != v7fsmount->devvp) {
                                DPRINTF("devvp %p != %p rootvp=%p\n", devvp,
                                    v7fsmount->devvp, rootvp);
                                if (rootvp == v7fsmount->devvp) {
                                        vrele(devvp);
                                        devvp = rootvp;
                                        vref(devvp);
                                } else {
                                        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 = v7fs_openfs(devvp, mp, l))) {
                        vrele(devvp);
                        return error;
                }

                if ((error = v7fs_mountfs(devvp, mp, args->endian))) {
                        v7fs_closefs(devvp, mp);
                        VOP_UNLOCK(devvp);
                        vrele(devvp);
                        return error;
                }
                VOP_UNLOCK(devvp);
        } 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);
}

static int
is_v7fs_partition(struct vnode *devvp)
{
        struct dkwedge_info dkw;
        int error;

        if ((error = getdiskinfo(devvp, &dkw)) != 0) {
                DPRINTF("getdiskinfo=%d\n", error);
                return error;
        }
        DPRINTF("ptype=%s size=%" PRIu64 "\n", dkw.dkw_ptype, dkw.dkw_size);

        return strcmp(dkw.dkw_ptype, DKW_PTYPE_V7) == 0 ? 0 : EINVAL;
}

static int
v7fs_openfs(struct vnode *devvp, struct mount *mp, struct lwp *l)
{
        kauth_cred_t cred = l->l_cred;
        int oflags;
        int error;

        /* Flush buffer */
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        if ((error = vinvalbuf(devvp, V_SAVE, cred, l, 0, 0)))
                goto unlock_exit;

        /* Open block device */
        oflags = FREAD;
        if ((mp->mnt_flag & MNT_RDONLY) == 0)
                oflags |= FWRITE;

        if ((error = VOP_OPEN(devvp, oflags, NOCRED)) != 0) {
                DPRINTF("VOP_OPEN=%d\n", error);
                goto unlock_exit;
        }

        return 0; /* lock held */

unlock_exit:
        VOP_UNLOCK(devvp);

        return error;
}

static void
v7fs_closefs(struct vnode *devvp, struct mount *mp)
{
        int oflags = FREAD;

        if ((mp->mnt_flag & MNT_RDONLY) == 0)
                oflags |= FWRITE;

        VOP_CLOSE(devvp, oflags, NOCRED);
}

static int
v7fs_mountfs(struct vnode *devvp, struct mount *mp, int endian)
{
        struct v7fs_mount *v7fsmount;
        int error;
        struct v7fs_mount_device mount;

        DPRINTF("%d\n",endian);

        v7fsmount = kmem_zalloc(sizeof(*v7fsmount), KM_SLEEP);
        v7fsmount->devvp = devvp;
        v7fsmount->mountp = mp;

        mount.device.vnode = devvp;
        mount.endian = endian;

        if ((error = v7fs_io_init(&v7fsmount->core, &mount, V7FS_BSIZE))) {
                goto err_exit;
        }
        struct v7fs_self *fs = v7fsmount->core;

        if ((error = v7fs_superblock_load(fs))) {
                v7fs_io_fini(fs);
                goto err_exit;
        }

        mp->mnt_data = v7fsmount;
        mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)devvp->v_rdev;
        mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_V7FS);
        mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
        mp->mnt_stat.f_namemax = V7FS_NAME_MAX;
        mp->mnt_flag |= MNT_LOCAL;
        mp->mnt_dev_bshift = V7FS_BSHIFT;
        mp->mnt_fs_bshift = V7FS_BSHIFT;

        return 0;

err_exit:
        kmem_free(v7fsmount, sizeof(*v7fsmount));
        return error;
}

int
v7fs_start(struct mount *mp, int flags)
{

        DPRINTF("\n");
        /* Nothing to do. */
        return 0;
}

int
v7fs_unmount(struct mount *mp, int mntflags)
{
        struct v7fs_mount *v7fsmount = (void *)mp->mnt_data;
        int error;

        DPRINTF("%p\n", v7fsmount);

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

        vn_lock(v7fsmount->devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_CLOSE(v7fsmount->devvp, FREAD, NOCRED);
        vput(v7fsmount->devvp);

        v7fs_io_fini(v7fsmount->core);

        kmem_free(v7fsmount, sizeof(*v7fsmount));
        mp->mnt_data = NULL;
        mp->mnt_flag &= ~MNT_LOCAL;

        return 0;
}

int
v7fs_root(struct mount *mp, int lktype, struct vnode **vpp)
{
        struct vnode *vp;
        int error;

        DPRINTF("\n");
        if ((error = VFS_VGET(mp, V7FS_ROOT_INODE, lktype, &vp)) != 0) {
                DPRINTF("error=%d\n", error);
                return error;
        }
        *vpp = vp;
        DPRINTF("done.\n");

        return 0;
}

int
v7fs_statvfs(struct mount *mp, struct statvfs *f)
{
        struct v7fs_mount *v7fsmount = mp->mnt_data;
        struct v7fs_self *fs = v7fsmount->core;

        DPRINTF("scratch remain=%d\n", fs->scratch_remain);

        v7fs_superblock_status(fs);

        f->f_bsize = V7FS_BSIZE;
        f->f_frsize = V7FS_BSIZE;
        f->f_iosize = V7FS_BSIZE;
        f->f_blocks = fs->stat.total_blocks;
        f->f_bfree = fs->stat.free_blocks;
        f->f_bavail = fs->stat.free_blocks;
        f->f_bresvd = 0;
        f->f_files = fs->stat.total_files;
        f->f_ffree = fs->stat.free_inode;
        f->f_favail = f->f_ffree;
        f->f_fresvd = 0;
        copy_statvfs_info(f, mp);

        return 0;
}

static bool
v7fs_sync_selector(void *cl, struct vnode *vp)
{
        struct v7fs_node *v7fs_node;

        KASSERT(mutex_owned(vp->v_interlock));

        v7fs_node = vp->v_data;
        if (v7fs_node == NULL)
                return false;
        if (!v7fs_inode_allocated(&v7fs_node->inode))
                return false;

        return true;
}

int
v7fs_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
{
        struct v7fs_mount *v7fsmount = mp->mnt_data;
        struct v7fs_self *fs = v7fsmount->core;
        struct vnode_iterator *marker;
        struct vnode *vp;
        int err, error;

        DPRINTF("\n");

        v7fs_superblock_writeback(fs);
        error = 0;
        vfs_vnode_iterator_init(mp, &marker);
        while ((vp = vfs_vnode_iterator_next(marker,
            v7fs_sync_selector, 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;
}

static enum vtype
v7fs_mode_to_vtype (v7fs_mode_t mode)
{
        enum vtype table[] = { VCHR, VDIR, VBLK, VREG, VLNK, VSOCK };

        if ((mode & V7FS_IFMT) == V7FSBSD_IFFIFO)
                return VFIFO;

        return table[((mode >> 13) & 7) - 1];
}

int
v7fs_loadvnode(struct mount *mp, struct vnode *vp,
    const void *key, size_t key_len, const void **new_key)
{
        struct v7fs_mount *v7fsmount;
        struct v7fs_self *fs;
        struct v7fs_node *v7fs_node;
        struct v7fs_inode inode;
        v7fs_ino_t number;
        int error;

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

        v7fsmount = mp->mnt_data;
        fs = v7fsmount->core;

        /* Lookup requested i-node */
        if ((error = v7fs_inode_load(fs, &inode, number))) {
                DPRINTF("v7fs_inode_load failed.\n");
                return error;
        }

        v7fs_node = pool_get(&v7fs_node_pool, PR_WAITOK);
        memset(v7fs_node, 0, sizeof(*v7fs_node));

        vp->v_tag = VT_V7FS;
        vp->v_data = v7fs_node;
        v7fs_node->vnode = vp;
        v7fs_node->v7fsmount = v7fsmount;
        v7fs_node->inode = inode;/*structure copy */
        v7fs_node->lockf = NULL; /* advlock */

        genfs_node_init(vp, &v7fs_genfsops);
        uvm_vnp_setsize(vp, v7fs_inode_filesize(&inode));

        if (number == V7FS_ROOT_INODE) {
                vp->v_type = VDIR;
                vp->v_vflag |= VV_ROOT;
                vp->v_op = v7fs_vnodeop_p;
        } else {
                vp->v_type = v7fs_mode_to_vtype(inode.mode);

                if (vp->v_type == VBLK || vp->v_type == VCHR) {
                        dev_t rdev = inode.device;
                        vp->v_op = v7fs_specop_p;
                        spec_node_init(vp, rdev);
                } else if (vp->v_type == VFIFO) {
                        vp->v_op = v7fs_fifoop_p;
                } else {
                        vp->v_op = v7fs_vnodeop_p;
                }
        }

        *new_key = &v7fs_node->inode.inode_number;

        return 0;
}


int
v7fs_vget(struct mount *mp, ino_t ino, int lktype, struct vnode **vpp)
{
        int error;
        v7fs_ino_t number;
        struct vnode *vp;

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

        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
v7fs_fhtovp(struct mount *mp, struct fid *fid, int lktype, struct vnode **vpp)
{

        DPRINTF("\n");
        /* notyet */
        return EOPNOTSUPP;
}

int
v7fs_vptofh(struct vnode *vpp, struct fid *fid, size_t *fh_size)
{

        DPRINTF("\n");
        /* notyet */
        return EOPNOTSUPP;
}

void
v7fs_init(void)
{

        DPRINTF("\n");
        pool_init(&v7fs_node_pool, sizeof(struct v7fs_node), 0, 0, 0,
            "v7fs_node_pool", &pool_allocator_nointr, IPL_NONE);
}

void
v7fs_reinit(void)
{

        /* Nothing to do. */
        DPRINTF("\n");
}

void
v7fs_done(void)
{

        DPRINTF("\n");
        pool_destroy(&v7fs_node_pool);
}

int
v7fs_gop_alloc(struct vnode *vp, off_t off, off_t len, int flags,
    kauth_cred_t cred)
{

        DPRINTF("\n");
        return 0;
}

int
v7fs_mountroot(void)
{
        struct mount *mp;
        int error;

        DPRINTF("");
        /* On mountroot, devvp (rootdev) is opened by vfs_mountroot */
        if ((error = is_v7fs_partition (rootvp)))
                return error;

        if ((error = vfs_rootmountalloc(MOUNT_V7FS, "root_device", &mp))) {
                DPRINTF("mountalloc error=%d\n", error);
                vrele(rootvp);
                return error;
        }

        if ((error = v7fs_mountfs(rootvp, mp, _BYTE_ORDER))) {
                DPRINTF("mountfs error=%d\n", error);
                vfs_unbusy(mp);
                vfs_rele(mp);
                return error;
        }

        mountlist_append(mp);

        vfs_unbusy(mp);

        return 0;
}