/*      $NetBSD: rump_vfs.c,v 1.97 2023/09/23 18:21:12 ad Exp $ */

/*
 * Copyright (c) 2008 Antti Kantee.  All Rights Reserved.
 *
 * Development of this software was supported by the
 * Finnish Cultural Foundation.
 *
 * 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 AUTHOR ``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 AUTHOR 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: rump_vfs.c,v 1.97 2023/09/23 18:21:12 ad Exp $");

#include <sys/param.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/evcnt.h>
#include <sys/fcntl.h>
#include <sys/filedesc.h>
#include <sys/fstrans.h>
#include <sys/lockf.h>
#include <sys/kthread.h>
#include <sys/module.h>
#include <sys/namei.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/vfs_syscalls.h>
#include <sys/vnode.h>
#include <sys/wapbl.h>
#include <sys/bufq.h>

#include <miscfs/specfs/specdev.h>

#include <rump-sys/kern.h>
#include <rump-sys/vfs.h>

#include <rump/rump.h>
#include <rump/rumpuser.h>

const char *rootfstype = ROOT_FSTYPE_ANY;

static void
pvfs_init(struct proc *p)
{

        p->p_cwdi = cwdinit();
}

static void
pvfs_rele(struct proc *p)
{

        cwdfree(p->p_cwdi);
}

static void
fini(void)
{

        vfs_shutdown();
        rumpblk_fini();
}

static void
drainbufs(int npages)
{

        mutex_enter(&bufcache_lock);
        buf_drain(npages);
        mutex_exit(&bufcache_lock);
}

RUMP_COMPONENT(RUMP__FACTION_VFS)
{
        extern struct vfsops rumpfs_vfsops;
        char buf[64];
        char *mbase;
        int rv, i;

        /* initialize indirect interfaces */
        rump_vfs_fini = fini;
        rump_vfs_drainbufs = drainbufs;

        if (rumpuser_getparam("RUMP_NVNODES", buf, sizeof(buf)) == 0) {
                desiredvnodes = strtoul(buf, NULL, 10);
        } else {
                desiredvnodes = 1<<10;
        }

        rumpblk_init();

        for (i = 0; i < ncpu; i++) {
                struct cpu_info *ci = cpu_lookup(i);
                cache_cpu_init(ci);
        }

        /* make number of bufpages 5% of total memory limit */
        if (rump_physmemlimit != RUMPMEM_UNLIMITED) {
                extern u_int bufpages;
                bufpages = rump_physmemlimit / (20 * PAGE_SIZE);
        }

        bufq_init();
        fstrans_init();
        vfsinit();
        bufinit();
        lf_init();
        spec_init();

        root_device = &rump_rootdev;

        /* bootstrap cwdi (rest done in vfs_mountroot() */
        proc0.p_cwdi = &cwdi0;
        proc0.p_cwdi = cwdinit();

        vfs_attach(&rumpfs_vfsops);
        vfs_mountroot();

        /* "mtree": create /dev and /tmp */
        do_sys_mkdir("/dev", 0755, UIO_SYSSPACE);
        do_sys_mkdir("/tmp", 01777, UIO_SYSSPACE);
        do_sys_chmodat(curlwp, AT_FDCWD, "/tmp", 01777, 0);

        rump_proc_vfs_init = pvfs_init;
        rump_proc_vfs_release = pvfs_rele;

        if (rump_threads) {
                if ((rv = kthread_create(PRI_IOFLUSH, KTHREAD_MPSAFE, NULL,
                    sched_sync, NULL, NULL, "ioflush")) != 0)
                        panic("syncer thread create failed: %d", rv);
        } else {
                syncdelay = 0;
        }

        /*
         * On archs where the native kernel ABI is supported, map
         * host module directory to rump.  This means that kernel
         * modules from the host will be autoloaded to rump kernels.
         */
        if (rump_nativeabi_p()) {
                if (rumpuser_getparam("RUMP_MODULEBASE", buf, sizeof(buf)) == 0)
                        mbase = buf;
                else
                        mbase = module_base;

                if (strlen(mbase) != 0 && *mbase != '0') {
                        rump_etfs_register(module_base, mbase,
                            RUMP_ETFS_DIR_SUBDIRS);
                }
        }

        module_init_class(MODULE_CLASS_BUFQ);
        module_init_class(MODULE_CLASS_VFS);

        /*
         * Don't build device names for a large set of devices by
         * default.  While the pseudo-devfs is a fun experiment,
         * creating many many device nodes may increase rump kernel
         * bootstrap time by ~40%.  Device nodes should be created
         * per-demand in the component constructors.
         */
#if 0
        {
        extern struct devsw_conv devsw_conv0[];
        extern int max_devsw_convs;
        rump_vfs_builddevs(devsw_conv0, max_devsw_convs);
        }
#else
        rump_vfs_builddevs(NULL, 0);
#endif

        /* attach null device and create /dev/{null,zero} */
        rump_devnull_init();

        rump_component_init(RUMP_COMPONENT_VFS);
}

struct rumpcn {
        struct componentname rcn_cn;
        char *rcn_path;
};

struct componentname *
rump_makecn(u_long nameiop, u_long flags, const char *name, size_t namelen,
        kauth_cred_t creds, struct lwp *l)
{
        struct rumpcn *rcn;
        struct componentname *cnp;

        rcn = kmem_zalloc(sizeof(*rcn), KM_SLEEP);
        cnp = &rcn->rcn_cn;

        rcn->rcn_path = PNBUF_GET();
        strlcpy(rcn->rcn_path, name, MAXPATHLEN);
        cnp->cn_nameptr = rcn->rcn_path;

        cnp->cn_nameiop = nameiop;
        cnp->cn_flags = flags & (MODMASK | PARAMASK);

        cnp->cn_namelen = namelen;

        cnp->cn_cred = creds;

        return cnp;
}

void
rump_freecn(struct componentname *cnp, int flags)
{
        struct rumpcn *rcn = (void *)cnp;

        if (flags & RUMPCN_FREECRED)
                rump_cred_put(cnp->cn_cred);

        PNBUF_PUT(rcn->rcn_path);
        kmem_free(rcn, sizeof(*rcn));
}

/* hey baby, what's your namei? */
int
rump_namei(uint32_t op, uint32_t flags, const char *namep,
        struct vnode **dvpp, struct vnode **vpp, struct componentname **cnpp)
{
        struct pathbuf *pb;
        struct nameidata nd;
        int rv;

        pb = pathbuf_create(namep);
        if (pb == NULL) {
                return ENOMEM;
        }
        NDINIT(&nd, op, flags, pb);
        rv = namei(&nd);
        if (rv) {
                pathbuf_destroy(pb);
                return rv;
        }

        if (dvpp) {
                KASSERT(flags & LOCKPARENT);
                *dvpp = nd.ni_dvp;
        } else {
                KASSERT((flags & LOCKPARENT) == 0);
        }

        if (vpp) {
                *vpp = nd.ni_vp;
        } else {
                if (nd.ni_vp) {
                        if (flags & LOCKLEAF)
                                vput(nd.ni_vp);
                        else
                                vrele(nd.ni_vp);
                }
        }

        if (cnpp) {
                struct componentname *cnp;

                cnp = kmem_alloc(sizeof(*cnp), KM_SLEEP);
                memcpy(cnp, &nd.ni_cnd, sizeof(*cnp));
                *cnpp = cnp;
        }
        pathbuf_destroy(pb);

        return rv;
}

void
rump_getvninfo(struct vnode *vp, enum rump_vtype *vtype,
        voff_t *vsize, dev_t *vdev)
{

        *vtype = (enum rump_vtype)vp->v_type;
        *vsize = vp->v_size;
        if (vp->v_specnode)
                *vdev = vp->v_rdev;
        else
                *vdev = 0;
}

struct vfsops *
rump_vfslist_iterate(struct vfsops *ops)
{

        if (ops == NULL)
                return LIST_FIRST(&vfs_list);
        else
                return LIST_NEXT(ops, vfs_list);
}

struct vfsops *
rump_vfs_getopsbyname(const char *name)
{

        return vfs_getopsbyname(name);
}

int
rump_vfs_getmp(const char *path, struct mount **mpp)
{
        struct vnode *vp;
        int rv;

        if ((rv = namei_simple_user(path, NSM_FOLLOW_TRYEMULROOT, &vp)) != 0)
                return rv;

        *mpp = vp->v_mount;
        vrele(vp);
        return 0;
}

struct vattr*
rump_vattr_init(void)
{
        struct vattr *vap;

        vap = kmem_alloc(sizeof(struct vattr), KM_SLEEP);
        vattr_null(vap);

        return vap;
}

void
rump_vattr_settype(struct vattr *vap, enum rump_vtype vt)
{

        vap->va_type = (enum vtype)vt;
}

void
rump_vattr_setmode(struct vattr *vap, mode_t mode)
{

        vap->va_mode = mode;
}

void
rump_vattr_setrdev(struct vattr *vap, dev_t dev)
{

        vap->va_rdev = dev;
}

void
rump_vattr_free(struct vattr *vap)
{

        kmem_free(vap, sizeof(*vap));
}

void
rump_vp_incref(struct vnode *vp)
{

        vref(vp);
}

int
rump_vp_getref(struct vnode *vp)
{

        return vrefcnt(vp);
}

void
rump_vp_rele(struct vnode *vp)
{

        vrele(vp);
}

void
rump_vp_interlock(struct vnode *vp)
{

        mutex_enter(vp->v_interlock);
}

void
rump_vp_vmobjlock(struct vnode *vp, int write)
{

        rw_enter(vp->v_uobj.vmobjlock, write ? RW_WRITER : RW_READER);
}

int
rump_vfs_unmount(struct mount *mp, int mntflags)
{

        return VFS_UNMOUNT(mp, mntflags);
}

int
rump_vfs_root(struct mount *mp, struct vnode **vpp, int lock)
{
        int rv;

        rv = VFS_ROOT(mp, LK_EXCLUSIVE, vpp);
        if (rv)
                return rv;

        if (!lock)
                VOP_UNLOCK(*vpp);

        return 0;
}

int
rump_vfs_statvfs(struct mount *mp, struct statvfs *sbp)
{

        return VFS_STATVFS(mp, sbp);
}

int
rump_vfs_sync(struct mount *mp, int wait, kauth_cred_t cred)
{

        return VFS_SYNC(mp, wait ? MNT_WAIT : MNT_NOWAIT, cred);
}

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

        return VFS_FHTOVP(mp, fid, LK_EXCLUSIVE, vpp);
}

int
rump_vfs_vptofh(struct vnode *vp, struct fid *fid, size_t *fidsize)
{

        return VFS_VPTOFH(vp, fid, fidsize);
}

int
rump_vfs_extattrctl(struct mount *mp, int cmd, struct vnode *vp,
        int attrnamespace, const char *attrname)
{

        return VFS_EXTATTRCTL(mp, cmd, vp, attrnamespace, attrname);
}

/*ARGSUSED*/
void
rump_vfs_syncwait(struct mount *mp)
{
        int n;

        n = vfs_syncwait();
        if (n)
                printf("syncwait: unsynced buffers: %d\n", n);
}

/*
 * Dump info about mount point.  No locking.
 */
static bool
rump_print_selector(void *cl, struct vnode *vp)
{
        int *full = cl;

        KASSERT(mutex_owned(vp->v_interlock));

        vfs_vnode_print(vp, *full, (void *)rumpuser_dprintf);
        return false;
}

void
rump_vfs_mount_print(const char *path, int full)
{
#ifdef DEBUGPRINT
        struct vnode *mvp;
        struct vnode_iterator *marker;
        int error;

        rumpuser_dprintf("\n==== dumping mountpoint at ``%s'' ====\n\n", path);
        if ((error = namei_simple_user(path, NSM_FOLLOW_NOEMULROOT, &mvp))!=0) {
                rumpuser_dprintf("==== lookup error %d ====\n\n", error);
                return;
        }
        vfs_mount_print(mvp->v_mount, full, (void *)rumpuser_dprintf);
        if (full) {
                rumpuser_dprintf("\n== dumping vnodes ==\n\n");
                vfs_vnode_iterator_init(mvp->v_mount, &marker);
                vfs_vnode_iterator_next(marker, rump_print_selector, &full);
                vfs_vnode_iterator_destroy(marker);
        }
        vrele(mvp);
        rumpuser_dprintf("\n==== done ====\n\n");
#else
        rumpuser_dprintf("mount dump not supported without DEBUGPRINT\n");
#endif
}

void
rump_biodone(void *arg, size_t count, int error)
{
        struct buf *bp = arg;

        bp->b_resid = bp->b_bcount - count;
        KASSERT(bp->b_resid >= 0);
        bp->b_error = error;

        biodone(bp);
}