ufs_quota.c

来自「早期freebsd实现」· C语言 代码 · 共 939 行 · 第 1/2 页

	dqflush(qvp);
	qvp->v_flag &= ~VSYSTEM;
	error = vn_close(qvp, FREAD|FWRITE, p->p_ucred, p);
	ump->um_quotas[type] = NULLVP;
	crfree(ump->um_cred[type]);
	ump->um_cred[type] = NOCRED;
	ump->um_qflags[type] &= ~QTF_CLOSING;
	for (type = 0; type < MAXQUOTAS; type++)
		if (ump->um_quotas[type] != NULLVP)
			break;
	if (type == MAXQUOTAS)
		mp->mnt_flag &= ~MNT_QUOTA;
	return (error);
}

/*
 * Q_GETQUOTA - return current values in a dqblk structure.
 */
int
getquota(mp, id, type, addr)
	struct mount *mp;
	u_long id;
	int type;
	caddr_t addr;
{
	struct dquot *dq;
	int error;

	if (error = dqget(NULLVP, id, VFSTOUFS(mp), type, &dq))
		return (error);
	error = copyout((caddr_t)&dq->dq_dqb, addr, sizeof (struct dqblk));
	dqrele(NULLVP, dq);
	return (error);
}

/*
 * Q_SETQUOTA - assign an entire dqblk structure.
 */
int
setquota(mp, id, type, addr)
	struct mount *mp;
	u_long id;
	int type;
	caddr_t addr;
{
	register struct dquot *dq;
	struct dquot *ndq;
	struct ufsmount *ump = VFSTOUFS(mp);
	struct dqblk newlim;
	int error;

	if (error = copyin(addr, (caddr_t)&newlim, sizeof (struct dqblk)))
		return (error);
	if (error = dqget(NULLVP, id, ump, type, &ndq))
		return (error);
	dq = ndq;
	while (dq->dq_flags & DQ_LOCK) {
		dq->dq_flags |= DQ_WANT;
		sleep((caddr_t)dq, PINOD+1);
	}
	/*
	 * Copy all but the current values.
	 * Reset time limit if previously had no soft limit or were
	 * under it, but now have a soft limit and are over it.
	 */
	newlim.dqb_curblocks = dq->dq_curblocks;
	newlim.dqb_curinodes = dq->dq_curinodes;
	if (dq->dq_id != 0) {
		newlim.dqb_btime = dq->dq_btime;
		newlim.dqb_itime = dq->dq_itime;
	}
	if (newlim.dqb_bsoftlimit &&
	    dq->dq_curblocks >= newlim.dqb_bsoftlimit &&
	    (dq->dq_bsoftlimit == 0 || dq->dq_curblocks < dq->dq_bsoftlimit))
		newlim.dqb_btime = time.tv_sec + ump->um_btime[type];
	if (newlim.dqb_isoftlimit &&
	    dq->dq_curinodes >= newlim.dqb_isoftlimit &&
	    (dq->dq_isoftlimit == 0 || dq->dq_curinodes < dq->dq_isoftlimit))
		newlim.dqb_itime = time.tv_sec + ump->um_itime[type];
	dq->dq_dqb = newlim;
	if (dq->dq_curblocks < dq->dq_bsoftlimit)
		dq->dq_flags &= ~DQ_BLKS;
	if (dq->dq_curinodes < dq->dq_isoftlimit)
		dq->dq_flags &= ~DQ_INODS;
	if (dq->dq_isoftlimit == 0 && dq->dq_bsoftlimit == 0 &&
	    dq->dq_ihardlimit == 0 && dq->dq_bhardlimit == 0)
		dq->dq_flags |= DQ_FAKE;
	else
		dq->dq_flags &= ~DQ_FAKE;
	dq->dq_flags |= DQ_MOD;
	dqrele(NULLVP, dq);
	return (0);
}

/*
 * Q_SETUSE - set current inode and block usage.
 */
int
setuse(mp, id, type, addr)
	struct mount *mp;
	u_long id;
	int type;
	caddr_t addr;
{
	register struct dquot *dq;
	struct ufsmount *ump = VFSTOUFS(mp);
	struct dquot *ndq;
	struct dqblk usage;
	int error;

	if (error = copyin(addr, (caddr_t)&usage, sizeof (struct dqblk)))
		return (error);
	if (error = dqget(NULLVP, id, ump, type, &ndq))
		return (error);
	dq = ndq;
	while (dq->dq_flags & DQ_LOCK) {
		dq->dq_flags |= DQ_WANT;
		sleep((caddr_t)dq, PINOD+1);
	}
	/*
	 * Reset time limit if have a soft limit and were
	 * previously under it, but are now over it.
	 */
	if (dq->dq_bsoftlimit && dq->dq_curblocks < dq->dq_bsoftlimit &&
	    usage.dqb_curblocks >= dq->dq_bsoftlimit)
		dq->dq_btime = time.tv_sec + ump->um_btime[type];
	if (dq->dq_isoftlimit && dq->dq_curinodes < dq->dq_isoftlimit &&
	    usage.dqb_curinodes >= dq->dq_isoftlimit)
		dq->dq_itime = time.tv_sec + ump->um_itime[type];
	dq->dq_curblocks = usage.dqb_curblocks;
	dq->dq_curinodes = usage.dqb_curinodes;
	if (dq->dq_curblocks < dq->dq_bsoftlimit)
		dq->dq_flags &= ~DQ_BLKS;
	if (dq->dq_curinodes < dq->dq_isoftlimit)
		dq->dq_flags &= ~DQ_INODS;
	dq->dq_flags |= DQ_MOD;
	dqrele(NULLVP, dq);
	return (0);
}

/*
 * Q_SYNC - sync quota files to disk.
 */
int
qsync(mp)
	struct mount *mp;
{
	struct ufsmount *ump = VFSTOUFS(mp);
	register struct vnode *vp, *nextvp;
	register struct dquot *dq;
	register int i;

	/*
	 * Check if the mount point has any quotas.
	 * If not, simply return.
	 */
	if ((mp->mnt_flag & MNT_MPBUSY) == 0)
		panic("qsync: not busy");
	for (i = 0; i < MAXQUOTAS; i++)
		if (ump->um_quotas[i] != NULLVP)
			break;
	if (i == MAXQUOTAS)
		return (0);
	/*
	 * Search vnodes associated with this mount point,
	 * synchronizing any modified dquot structures.
	 */
again:
	for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nextvp) {
		nextvp = vp->v_mntvnodes.le_next;
		if (VOP_ISLOCKED(vp))
			continue;
		if (vget(vp, 1))
			goto again;
		for (i = 0; i < MAXQUOTAS; i++) {
			dq = VTOI(vp)->i_dquot[i];
			if (dq != NODQUOT && (dq->dq_flags & DQ_MOD))
				dqsync(vp, dq);
		}
		vput(vp);
		if (vp->v_mntvnodes.le_next != nextvp || vp->v_mount != mp)
			goto again;
	}
	return (0);
}

/*
 * Code pertaining to management of the in-core dquot data structures.
 */
struct dquot **dqhashtbl;
u_long dqhash;

/*
 * Dquot free list.
 */
#define	DQUOTINC	5	/* minimum free dquots desired */
struct dquot *dqfreel, **dqback = &dqfreel;
long numdquot, desireddquot = DQUOTINC;

/*
 * Initialize the quota system.
 */
void
dqinit()
{

	dqhashtbl = hashinit(desiredvnodes, M_DQUOT, &dqhash);
}

/*
 * Obtain a dquot structure for the specified identifier and quota file
 * reading the information from the file if necessary.
 */
int
dqget(vp, id, ump, type, dqp)
	struct vnode *vp;
	u_long id;
	register struct ufsmount *ump;
	register int type;
	struct dquot **dqp;
{
	register struct dquot *dq, *dp, **dpp;
	register struct vnode *dqvp;
	struct iovec aiov;
	struct uio auio;
	int error;

	dqvp = ump->um_quotas[type];
	if (dqvp == NULLVP || (ump->um_qflags[type] & QTF_CLOSING)) {
		*dqp = NODQUOT;
		return (EINVAL);
	}
	/*
	 * Check the cache first.
	 */
	dpp = &dqhashtbl[((((int)(dqvp)) >> 8) + id) & dqhash];
	for (dq = *dpp; dq; dq = dq->dq_forw) {
		if (dq->dq_id != id ||
		    dq->dq_ump->um_quotas[dq->dq_type] != dqvp)
			continue;
		/*
		 * Cache hit with no references.  Take
		 * the structure off the free list.
		 */
		if (dq->dq_cnt == 0) {
			if ((dp = dq->dq_freef) != NODQUOT)
				dp->dq_freeb = dq->dq_freeb;
			else
				dqback = dq->dq_freeb;
			*dq->dq_freeb = dp;
		}
		DQREF(dq);
		*dqp = dq;
		return (0);
	}
	/*
	 * Not in cache, allocate a new one.
	 */
	if (dqfreel == NODQUOT && numdquot < MAXQUOTAS * desiredvnodes)
		desireddquot += DQUOTINC;
	if (numdquot < desireddquot) {
		dq = (struct dquot *)malloc(sizeof *dq, M_DQUOT, M_WAITOK);
		bzero((char *)dq, sizeof *dq);
		numdquot++;
	} else {
		if ((dq = dqfreel) == NULL) {
			tablefull("dquot");
			*dqp = NODQUOT;
			return (EUSERS);
		}
		if (dq->dq_cnt || (dq->dq_flags & DQ_MOD))
			panic("free dquot isn't");
		if ((dp = dq->dq_freef) != NODQUOT)
			dp->dq_freeb = &dqfreel;
		else
			dqback = &dqfreel;
		dqfreel = dp;
		dq->dq_freef = NULL;
		dq->dq_freeb = NULL;
		if (dp = dq->dq_forw)
			dp->dq_back = dq->dq_back;
		*dq->dq_back = dp;
	}
	/*
	 * Initialize the contents of the dquot structure.
	 */
	if (vp != dqvp)
		VOP_LOCK(dqvp);
	if (dp = *dpp)
		dp->dq_back = &dq->dq_forw;
	dq->dq_forw = dp;
	dq->dq_back = dpp;
	*dpp = dq;
	DQREF(dq);
	dq->dq_flags = DQ_LOCK;
	dq->dq_id = id;
	dq->dq_ump = ump;
	dq->dq_type = type;
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	aiov.iov_base = (caddr_t)&dq->dq_dqb;
	aiov.iov_len = sizeof (struct dqblk);
	auio.uio_resid = sizeof (struct dqblk);
	auio.uio_offset = (off_t)(id * sizeof (struct dqblk));
	auio.uio_segflg = UIO_SYSSPACE;
	auio.uio_rw = UIO_READ;
	auio.uio_procp = (struct proc *)0;
	error = VOP_READ(dqvp, &auio, 0, ump->um_cred[type]);
	if (auio.uio_resid == sizeof(struct dqblk) && error == 0)
		bzero((caddr_t)&dq->dq_dqb, sizeof(struct dqblk));
	if (vp != dqvp)
		VOP_UNLOCK(dqvp);
	if (dq->dq_flags & DQ_WANT)
		wakeup((caddr_t)dq);
	dq->dq_flags = 0;
	/*
	 * I/O error in reading quota file, release
	 * quota structure and reflect problem to caller.
	 */
	if (error) {
		if (dp = dq->dq_forw)
			dp->dq_back = dq->dq_back;
		*dq->dq_back = dp;
		dq->dq_forw = NULL;
		dq->dq_back = NULL;
		dqrele(vp, dq);
		*dqp = NODQUOT;
		return (error);
	}
	/*
	 * Check for no limit to enforce.
	 * Initialize time values if necessary.
	 */
	if (dq->dq_isoftlimit == 0 && dq->dq_bsoftlimit == 0 &&
	    dq->dq_ihardlimit == 0 && dq->dq_bhardlimit == 0)
		dq->dq_flags |= DQ_FAKE;
	if (dq->dq_id != 0) {
		if (dq->dq_btime == 0)
			dq->dq_btime = time.tv_sec + ump->um_btime[type];
		if (dq->dq_itime == 0)
			dq->dq_itime = time.tv_sec + ump->um_itime[type];
	}
	*dqp = dq;
	return (0);
}

/*
 * Obtain a reference to a dquot.
 */
void
dqref(dq)
	struct dquot *dq;
{

	dq->dq_cnt++;
}

/*
 * Release a reference to a dquot.
 */
void
dqrele(vp, dq)
	struct vnode *vp;
	register struct dquot *dq;
{

	if (dq == NODQUOT)
		return;
	if (dq->dq_cnt > 1) {
		dq->dq_cnt--;
		return;
	}
	if (dq->dq_flags & DQ_MOD)
		(void) dqsync(vp, dq);
	if (--dq->dq_cnt > 0)
		return;
	if (dqfreel != NODQUOT) {
		*dqback = dq;
		dq->dq_freeb = dqback;
	} else {
		dqfreel = dq;
		dq->dq_freeb = &dqfreel;
	}
	dq->dq_freef = NODQUOT;
	dqback = &dq->dq_freef;
}

/*
 * Update the disk quota in the quota file.
 */
int
dqsync(vp, dq)
	struct vnode *vp;
	register struct dquot *dq;
{
	struct vnode *dqvp;
	struct iovec aiov;
	struct uio auio;
	int error;

	if (dq == NODQUOT)
		panic("dqsync: dquot");
	if ((dq->dq_flags & DQ_MOD) == 0)
		return (0);
	if ((dqvp = dq->dq_ump->um_quotas[dq->dq_type]) == NULLVP)
		panic("dqsync: file");
	if (vp != dqvp)
		VOP_LOCK(dqvp);
	while (dq->dq_flags & DQ_LOCK) {
		dq->dq_flags |= DQ_WANT;
		sleep((caddr_t)dq, PINOD+2);
		if ((dq->dq_flags & DQ_MOD) == 0) {
			if (vp != dqvp)
				VOP_UNLOCK(dqvp);
			return (0);
		}
	}
	dq->dq_flags |= DQ_LOCK;
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	aiov.iov_base = (caddr_t)&dq->dq_dqb;
	aiov.iov_len = sizeof (struct dqblk);
	auio.uio_resid = sizeof (struct dqblk);
	auio.uio_offset = (off_t)(dq->dq_id * sizeof (struct dqblk));
	auio.uio_segflg = UIO_SYSSPACE;
	auio.uio_rw = UIO_WRITE;
	auio.uio_procp = (struct proc *)0;
	error = VOP_WRITE(dqvp, &auio, 0, dq->dq_ump->um_cred[dq->dq_type]);
	if (auio.uio_resid && error == 0)
		error = EIO;
	if (dq->dq_flags & DQ_WANT)
		wakeup((caddr_t)dq);
	dq->dq_flags &= ~(DQ_MOD|DQ_LOCK|DQ_WANT);
	if (vp != dqvp)
		VOP_UNLOCK(dqvp);
	return (error);
}

/*
 * Flush all entries from the cache for a particular vnode.
 */
void
dqflush(vp)
	register struct vnode *vp;
{
	register struct dquot *dq, *dp, **dpp, *nextdq;

	/*
	 * Move all dquot's that used to refer to this quota
	 * file off their hash chains (they will eventually
	 * fall off the head of the free list and be re-used).
	 */
	for (dpp = &dqhashtbl[dqhash]; dpp >= dqhashtbl; dpp--) {
		for (dq = *dpp; dq; dq = nextdq) {
			nextdq = dq->dq_forw;
			if (dq->dq_ump->um_quotas[dq->dq_type] != vp)
				continue;
			if (dq->dq_cnt)
				panic("dqflush: stray dquot");
			if (dp = dq->dq_forw)
				dp->dq_back = dq->dq_back;
			*dq->dq_back = dp;
			dq->dq_forw = NULL;
			dq->dq_back = NULL;
			dq->dq_ump = (struct ufsmount *)0;
		}
	}
}