librump/rumpvfs/rump_vfs.c

/*	$NetBSD: rump_vfs.c,v 1.24 2009/08/03 14:23:30 pooka 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 1.24 2009/08/03 14:23:30 pooka Exp $");

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

#include <miscfs/specfs/specdev.h>
#include <miscfs/syncfs/syncfs.h>

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

#include "rump_private.h"
#include "rump_vfs_private.h"

static struct cwdinfo rump_cwdi;

static void rump_rcvp_lwpset(struct vnode *, struct vnode *, struct lwp *);

static void
pvfs_init(struct proc *p)
{

	p->p_cwdi = cwdinit();
}

static void
pvfs_rele(struct proc *p)
{

	cwdfree(p->p_cwdi);
}

void
rump_vfs_init(void)
{
	char buf[64];
	int error;

	dovfsusermount = 1;

	if (rumpuser_getenv("RUMP_NVNODES", buf, sizeof(buf), &error) == 0) {
		desiredvnodes = strtoul(buf, NULL, 10);
	} else {
		desiredvnodes = 1<<16;
	}

	rumpblk_init();

	cache_cpu_init(&rump_cpu);
	vfsinit();
	bufinit();
	wapbl_init();
	cwd_sys_init();
	lf_init();

	rumpuser_bioinit(rump_biodone);
	rumpfs_init();

	rump_proc_vfs_init = pvfs_init;
	rump_proc_vfs_release = pvfs_rele;

	/* bootstrap cwdi */
	rw_init(&rump_cwdi.cwdi_lock);
	rump_cwdi.cwdi_cdir = rootvnode;
	vref(rump_cwdi.cwdi_cdir);
	proc0.p_cwdi = &rump_cwdi;
	proc0.p_cwdi = cwdinit();

	if (rump_threads) {
		int rv;

		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;
	}
}

struct mount *
rump_mnt_init(struct vfsops *vfsops, int mntflags)
{
	struct mount *mp;

	mp = kmem_zalloc(sizeof(struct mount), KM_SLEEP);

	mp->mnt_op = vfsops;
	mp->mnt_flag = mntflags;
	TAILQ_INIT(&mp->mnt_vnodelist);
	rw_init(&mp->mnt_unmounting);
	mutex_init(&mp->mnt_updating, MUTEX_DEFAULT, IPL_NONE);
	mutex_init(&mp->mnt_renamelock, MUTEX_DEFAULT, IPL_NONE);
	mp->mnt_refcnt = 1;
	mp->mnt_vnodecovered = rootvnode;

	mount_initspecific(mp);

	return mp;
}

int
rump_mnt_mount(struct mount *mp, const char *path, void *data, size_t *dlen)
{
	struct vnode *rvp;
	int rv;

	rv = VFS_MOUNT(mp, path, data, dlen);
	if (rv)
		return rv;

	(void) VFS_STATVFS(mp, &mp->mnt_stat);
	rv = VFS_START(mp, 0);
	if (rv) {
		VFS_UNMOUNT(mp, MNT_FORCE);
		return rv;
	}

	/*
	 * XXX: set a root for lwp0.  This is strictly not correct,
	 * but makes things work for single fs case without having
	 * to manually call rump_rcvp_set().
	 */
	VFS_ROOT(mp, &rvp);
	rump_rcvp_lwpset(rvp, rvp, &lwp0);
	vput(rvp);

	return rv;
}

void
rump_mnt_destroy(struct mount *mp)
{

	/* See rcvp XXX above */
	rump_cwdi.cwdi_rdir = NULL;
	vref(rootvnode);
	rump_cwdi.cwdi_cdir = rootvnode;

	mount_finispecific(mp);
	kmem_free(mp, sizeof(*mp));
}

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

	cnp = kmem_zalloc(sizeof(struct componentname), KM_SLEEP);

	cnp->cn_nameiop = nameiop;
	cnp->cn_flags = flags | HASBUF;

	cnp->cn_pnbuf = PNBUF_GET();
	strcpy(cnp->cn_pnbuf, name);
	cnp->cn_nameptr = cnp->cn_pnbuf;
	cnp->cn_namelen = namelen;
	cnp->cn_hash = namei_hash(name, &cp);

	cnp->cn_cred = creds;

	return cnp;
}

void
rump_freecn(struct componentname *cnp, int flags)
{

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

	if (cnp->cn_flags & SAVENAME) {
		if (flags & RUMPCN_ISLOOKUP || cnp->cn_flags & SAVESTART)
			PNBUF_PUT(cnp->cn_pnbuf);
	} else {
		PNBUF_PUT(cnp->cn_pnbuf);
	}
	kmem_free(cnp, sizeof(*cnp));
}

/* 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 nameidata nd;
	int rv;

	NDINIT(&nd, op, flags, UIO_SYSSPACE, namep);
	rv = namei(&nd);
	if (rv)
		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;
	} else if (nd.ni_cnd.cn_flags & HASBUF) {
		panic("%s: pathbuf mismatch", __func__);
	}

	return rv;
}

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

	*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 vtype vt)
{

	vap->va_type = 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)
{

	mutex_enter(&vp->v_interlock);
	++vp->v_usecount;
	mutex_exit(&vp->v_interlock);
}

int
rump_vp_getref(struct vnode *vp)
{

	return vp->v_usecount;
}

void
rump_vp_decref(struct vnode *vp)
{

	mutex_enter(&vp->v_interlock);
	--vp->v_usecount;
	mutex_exit(&vp->v_interlock);
}

/*
 * Really really recycle with a cherry on top.  We should be
 * extra-sure we can do this.  For example with p2k there is
 * no problem, since puffs in the kernel takes care of refcounting
 * for us.
 */
void
rump_vp_recycle_nokidding(struct vnode *vp)
{

	mutex_enter(&vp->v_interlock);
	vp->v_usecount = 1;
	/*
	 * XXX: NFS holds a reference to the root vnode, so don't clean
	 * it out.  This is very wrong, but fixing it properly would
	 * take too much effort for now
	 */
	if (vp->v_tag == VT_NFS && vp->v_vflag & VV_ROOT) {
		mutex_exit(&vp->v_interlock);
		return;
	}
	vclean(vp, DOCLOSE);
	vrelel(vp, 0);
}

void
rump_vp_rele(struct vnode *vp)
{

	vrele(vp);
}

void
rump_vp_interlock(struct vnode *vp)
{

	mutex_enter(&vp->v_interlock);
}

int
rump_vfs_unmount(struct mount *mp, int mntflags)
{
#if 0
	struct evcnt *ev;

	printf("event counters:\n");
	TAILQ_FOREACH(ev, &allevents, ev_list)
		printf("%s: %llu\n", ev->ev_name, ev->ev_count);
#endif

	return VFS_UNMOUNT(mp, mntflags);
}

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

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

	if (!lock)
		VOP_UNLOCK(*vpp, 0);

	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, vpp);
}

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

	return VFS_VPTOFH(vp, fid, fidsize);
}

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

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

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);
}

static void
rump_rcvp_lwpset(struct vnode *rvp, struct vnode *cvp, struct lwp *l)
{
	struct cwdinfo *cwdi = l->l_proc->p_cwdi;

	KASSERT(cvp);

	rw_enter(&cwdi->cwdi_lock, RW_WRITER);
	if (cwdi->cwdi_rdir)
		vrele(cwdi->cwdi_rdir);
	if (rvp)
		vref(rvp);
	cwdi->cwdi_rdir = rvp;

	vrele(cwdi->cwdi_cdir);
	vref(cvp);
	cwdi->cwdi_cdir = cvp;
	rw_exit(&cwdi->cwdi_lock);
}

void
rump_rcvp_set(struct vnode *rvp, struct vnode *cvp)
{

	rump_rcvp_lwpset(rvp, cvp, curlwp);
}

struct vnode *
rump_cdir_get(void)
{
	struct vnode *vp;
	struct cwdinfo *cwdi = curlwp->l_proc->p_cwdi;

	rw_enter(&cwdi->cwdi_lock, RW_READER);
	vp = cwdi->cwdi_cdir;
	rw_exit(&cwdi->cwdi_lock);
	vref(vp);

	return vp;
}