kern/src/ns/pgrp.c

/* Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
 * Portions Copyright © 1997-1999 Vita Nuova Limited
 * Portions Copyright © 2000-2007 Vita Nuova Holdings Limited
 *                                (www.vitanuova.com)
 * Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
 *
 * Modified for the Akaros operating system:
 * Copyright (c) 2013-2014 The Regents of the University of California
 * Copyright (c) 2013-2015 Google Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE. */

#include <slab.h>
#include <kmalloc.h>
#include <kref.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <error.h>
#include <cpio.h>
#include <pmap.h>
#include <smp.h>
#include <net/ip.h>

/* TODO: (ID) need a unique ID service.  These will loop around... */
static int pgrpid;
static int mountid;
#define NEXT_ID(x) (__sync_add_and_fetch(&(x), 1))

void closepgrp(struct pgrp *p)
{
	struct mhead **h, **e, *f, *next;

	wlock(&p->ns);
	p->pgrpid = -1;

	e = &p->mnthash[MNTHASH];
	for (h = p->mnthash; h < e; h++) {
		for (f = *h; f; f = next) {
			wlock(&f->lock);
			cclose(f->from);
			mountfree(f->mount);
			f->mount = NULL;
			next = f->hash;
			wunlock(&f->lock);
			putmhead(f);
		}
	}
	wunlock(&p->ns);
	kfree(p);
}

static void freepgrp(struct kref *k)
{
	struct pgrp *p = container_of(k, struct pgrp, ref);
	closepgrp(p);
}

struct pgrp *newpgrp(void)
{
	struct pgrp *p;

	p = kzmalloc(sizeof(struct pgrp), MEM_WAIT);
	kref_init(&p->ref, freepgrp, 1);
	p->pgrpid = NEXT_ID(pgrpid);
	p->progmode = 0644;
	qlock_init(&p->debug);
	rwinit(&p->ns);
	qlock_init(&p->nsh);
	return p;
}

void pgrpinsert(struct mount **order, struct mount *m)
{
	struct mount *f;

	m->order = 0;
	if (*order == 0) {
		*order = m;
		return;
	}
	for (f = *order; f; f = f->order) {
		if (m->mountid < f->mountid) {
			m->order = f;
			*order = m;
			return;
		}
		order = &f->order;
	}
	*order = m;
}

/*
 * pgrpcpy MUST preserve the mountid allocation order of the parent group
 */
void pgrpcpy(struct pgrp *to, struct pgrp *from)
{
	ERRSTACK(2);
	int i;
	struct mount *n, *m, **link, *order;
	struct mhead *f, **tom, **l, *mh;

	wlock(&from->ns);
	if (waserror()) {
		wunlock(&from->ns);
		nexterror();
	}
	order = 0;
	tom = to->mnthash;
	for (i = 0; i < MNTHASH; i++) {
		l = tom++;
		for (f = from->mnthash[i]; f; f = f->hash) {
			rlock(&f->lock);
			if (waserror()) {
				runlock(&f->lock);
				nexterror();
			}
			mh = newmhead(f->from);
			if (!mh)
				error(ENOMEM, ERROR_FIXME);
			*l = mh;
			l = &mh->hash;
			link = &mh->mount;
			for (m = f->mount; m; m = m->next) {
				n = newmount(mh, m->to, m->mflag, m->spec);
				m->copy = n;
				pgrpinsert(&order, m);
				*link = n;
				link = &n->next;
			}
			poperror();
			runlock(&f->lock);
		}
	}
	/*
	 * Allocate mount ids in the same sequence as the parent group
	 */
	/* should probably protect with a spinlock and be done with it */
	for (m = order; m; m = m->order) {
		m->copy->mountid = NEXT_ID(mountid);
	}

	to->progmode = from->progmode;
	to->nodevs = from->nodevs;

	poperror();
	wunlock(&from->ns);
}

struct mount *newmount(struct mhead *mh, struct chan *to, int flag, char *spec)
{
	struct mount *m;

	m = kzmalloc(sizeof(struct mount), 0);
	m->to = to;
	m->head = mh;
	chan_incref(to);
	m->mountid = NEXT_ID(mountid);
	m->mflag = flag;
	if (spec != 0)
		kstrdup(&m->spec, spec);

	return m;
}

void mountfree(struct mount *m)
{
	struct mount *f;

	while (m) {
		f = m->next;
		cclose(m->to);
		m->mountid = 0;
		kfree(m->spec);
		kfree(m);
		m = f;
	}
}

#if 0
almost certainly not needed.void resrcwait(char *reason)
{
	char *p;

	if (current == 0)
		panic("resrcwait");

	p = up->psstate;
	if (reason) {
		up->psstate = reason;
		printd("%s\n", reason);
	}

	kthread_usleep(300 * 1000);
	up->psstate = p;
}
#endif

/* TODO: We don't have any alloc / initializer methods for skeyset or signerkey
 * yet.  When we do, use these releases for their kref_init. */
static void __sigs_release(struct kref *kref)
{
	struct skeyset *s = container_of(kref, struct skeyset, ref);
	int i;
	for (i = 0; i < s->nkey; i++)
		freeskey(s->keys[i]);
	kfree(s);
}

void closesigs(struct skeyset *s)
{
	if (!s)
		return;
	kref_put(&s->ref);
}

static void __key_release(struct kref *kref)
{
	struct signerkey *key = container_of(kref, struct signerkey, ref);
	kfree(key->owner);
	(*key->pkfree) (key->pk);
	kfree(key);
}

void freeskey(struct signerkey *key)
{
	if (!key)
		return;
	kref_put(&key->ref);
}