path: root/fs/xfs/quota/xfs_dquot_item.c

/*
 * Copyright (c) 2000-2003 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_alloc.h"
#include "xfs_dmapi.h"
#include "xfs_quota.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_bmap.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_itable.h"
#include "xfs_rw.h"
#include "xfs_acl.h"
#include "xfs_cap.h"
#include "xfs_mac.h"
#include "xfs_attr.h"
#include "xfs_buf_item.h"
#include "xfs_trans_priv.h"
#include "xfs_qm.h"

/*
 * returns the number of iovecs needed to log the given dquot item.
 */
/* ARGSUSED */
STATIC uint
xfs_qm_dquot_logitem_size(
	xfs_dq_logitem_t	*logitem)
{
	/*
	 * we need only two iovecs, one for the format, one for the real thing
	 */
	return (2);
}

/*
 * fills in the vector of log iovecs for the given dquot log item.
 */
STATIC void
xfs_qm_dquot_logitem_format(
	xfs_dq_logitem_t	*logitem,
	xfs_log_iovec_t		*logvec)
{
	ASSERT(logitem);
	ASSERT(logitem->qli_dquot);

	logvec->i_addr = (xfs_caddr_t)&logitem->qli_format;
	logvec->i_len  = sizeof(xfs_dq_logformat_t);
	XLOG_VEC_SET_TYPE(logvec, XLOG_REG_TYPE_QFORMAT);
	logvec++;
	logvec->i_addr = (xfs_caddr_t)&logitem->qli_dquot->q_core;
	logvec->i_len  = sizeof(xfs_disk_dquot_t);
	XLOG_VEC_SET_TYPE(logvec, XLOG_REG_TYPE_DQUOT);

	ASSERT(2 == logitem->qli_item.li_desc->lid_size);
	logitem->qli_format.qlf_size = 2;

}

/*
 * Increment the pin count of the given dquot.
 * This value is protected by pinlock spinlock in the xQM structure.
 */
STATIC void
xfs_qm_dquot_logitem_pin(
	xfs_dq_logitem_t *logitem)
{
	unsigned long	s;
	xfs_dquot_t *dqp;

	dqp = logitem->qli_dquot;
	ASSERT(XFS_DQ_IS_LOCKED(dqp));
	s = XFS_DQ_PINLOCK(dqp);
	dqp->q_pincount++;
	XFS_DQ_PINUNLOCK(dqp, s);
}

/*
 * Decrement the pin count of the given dquot, and wake up
 * anyone in xfs_dqwait_unpin() if the count goes to 0.	 The
 * dquot must have been previously pinned with a call to xfs_dqpin().
 */
/* ARGSUSED */
STATIC void
xfs_qm_dquot_logitem_unpin(
	xfs_dq_logitem_t *logitem,
	int		  stale)
{
	unsigned long	s;
	xfs_dquot_t *dqp;

	dqp = logitem->qli_dquot;
	ASSERT(dqp->q_pincount > 0);
	s = XFS_DQ_PINLOCK(dqp);
	dqp->q_pincount--;
	if (dqp->q_pincount == 0) {
		sv_broadcast(&dqp->q_pinwait);
	}
	XFS_DQ_PINUNLOCK(dqp, s);
}

/* ARGSUSED */
STATIC void
xfs_qm_dquot_logitem_unpin_remove(
	xfs_dq_logitem_t *logitem,
	xfs_trans_t	 *tp)
{
	xfs_qm_dquot_logitem_unpin(logitem, 0);
}

/*
 * Given the logitem, this writes the corresponding dquot entry to disk
 * asynchronously. This is called with the dquot entry securely locked;
 * we simply get xfs_qm_dqflush() to do the work, and unlock the dquot
 * at the end.
 */
STATIC void
xfs_qm_dquot_logitem_push(
	xfs_dq_logitem_t	*logitem)
{
	xfs_dquot_t	*dqp;

	dqp = logitem->qli_dquot;

	ASSERT(XFS_DQ_IS_LOCKED(dqp));
	ASSERT(XFS_DQ_IS_FLUSH_LOCKED(dqp));

	/*
	 * Since we were able to lock the dquot's flush lock and
	 * we found it on the AIL, the dquot must be dirty.  This
	 * is because the dquot is removed from the AIL while still
	 * holding the flush lock in xfs_dqflush_done().  Thus, if
	 * we found it in the AIL and were able to obtain the flush
	 * lock without sleeping, then there must not have been
	 * anyone in the process of flushing the dquot.
	 */
	xfs_qm_dqflush(dqp, XFS_B_DELWRI);
	xfs_dqunlock(dqp);
}

/*ARGSUSED*/
STATIC xfs_lsn_t
xfs_qm_dquot_logitem_committed(
	xfs_dq_logitem_t	*l,
	xfs_lsn_t		lsn)
{
	/*
	 * We always re-log the entire dquot when it becomes dirty,
	 * so, the latest copy _is_ the only one that matters.
	 */
	return (lsn);
}


/*
 * This is called to wait for the given dquot to be unpinned.
 * Most of these pin/unpin routines are plagiarized from inode code.
 */
void
xfs_qm_dqunpin_wait(
	xfs_dquot_t	*dqp)
{
	SPLDECL(s);

	ASSERT(XFS_DQ_IS_LOCKED(dqp));
	if (dqp->q_pincount == 0) {
		return;
	}

	/*
	 * Give the log a push so we don't wait here too long.
	 */
	xfs_log_force(dqp->q_mount, (xfs_lsn_t)0, XFS_LOG_FORCE);
	s = XFS_DQ_PINLOCK(dqp);
	if (dqp->q_pincount == 0) {
		XFS_DQ_PINUNLOCK(dqp, s);
		return;
	}
	sv_wait(&(dqp->q_pinwait), PINOD,
		&(XFS_DQ_TO_QINF(dqp)->qi_pinlock), s);
}

/*
 * This is called when IOP_TRYLOCK returns XFS_ITEM_PUSHBUF to indicate that
 * the dquot is locked by us, but the flush lock isn't. So, here we are
 * going to see if the relevant dquot buffer is incore, waiting on DELWRI.
 * If so, we want to push it out to help us take this item off the AIL as soon
 * as possible.
 *
 * We must not be holding the AIL_LOCK at this point. Calling incore() to
 * search the buffer cache can be a time consuming thing, and AIL_LOCK is a
 * spinlock.
 */
STATIC void
xfs_qm_dquot_logitem_pushbuf(
	xfs_dq_logitem_t    *qip)
{
	xfs_dquot_t	*dqp;
	xfs_mount_t	*mp;
	xfs_buf_t	*bp;
	uint		dopush;

	dqp = qip->qli_dquot;
	ASSERT(XFS_DQ_IS_LOCKED(dqp));

	/*
	 * The qli_pushbuf_flag keeps others from
	 * trying to duplicate our effort.
	 */
	ASSERT(qip->qli_pushbuf_flag != 0);
	ASSERT(qip->qli_push_owner == current_pid());

	/*
	 * If flushlock isn't locked anymore, chances are that the
	 * inode flush completed and the inode was taken off the AIL.
	 * So, just get out.
	 */
	if (!issemalocked(&(dqp->q_flock))  ||
	    ((qip->qli_item.li_flags & XFS_LI_IN_AIL) == 0)) {
		qip->qli_pushbuf_flag = 0;
		xfs_dqunlock(dqp);
		return;
	}
	mp = dqp->q_mount;
	bp = xfs_incore(mp->m_ddev_targp, qip->qli_format.qlf_blkno,
		    XFS_QI_DQCHUNKLEN(mp),
		    XFS_INCORE_TRYLOCK);
	if (bp != NULL) {
		if (XFS_BUF_ISDELAYWRITE(bp)) {
			dopush = ((qip->qli_item.li_flags & XFS_LI_IN_AIL) &&
				  issemalocked(&(dqp->q_flock)));
			qip->qli_pushbuf_flag = 0;
			xfs_dqunlock(dqp);

			if (XFS_BUF_ISPINNED(bp)) {
				xfs_log_force(mp, (xfs_lsn_t)0,
					      XFS_LOG_FORCE);
			}
			if (dopush) {
#ifdef XFSRACEDEBUG
				delay_for_intr();
				delay(300);
#endif
				xfs_bawrite(mp, bp);
			} else {
				xfs_buf_relse(bp);
			}
		} else {
			qip->qli_pushbuf_flag = 0;
			xfs_dqunlock(dqp);
			xfs_buf_relse(bp);
		}
		return;
	}

	qip->qli_pushbuf_flag = 0;
	xfs_dqunlock(dqp);
}

/*
 * This is called to attempt to lock the dquot associated with this
 * dquot log item.  Don't sleep on the dquot lock or the flush lock.
 * If the flush lock is already held, indicating that the dquot has
 * been or is in the process of being flushed, then see if we can
 * find the dquot's buffer in the buffer cache without sleeping.  If
 * we can and it is marked delayed write, then we want to send it out.
 * We delay doing so until the push routine, though, to avoid sleeping
 * in any device strategy routines.
 */
STATIC uint
xfs_qm_dquot_logitem_trylock(
	xfs_dq_logitem_t	*qip)
{
	xfs_dquot_t		*dqp;
	uint			retval;

	dqp = qip->qli_dquot;
	if (dqp->q_pincount > 0)
		return (XFS_ITEM_PINNED);

	if (! xfs_qm_dqlock_nowait(dqp))
		return (XFS_ITEM_LOCKED);

	retval = XFS_ITEM_SUCCESS;
	if (! xfs_qm_dqflock_nowait(dqp)) {
		/*
		 * The dquot is already being flushed.	It may have been
		 * flushed delayed write, however, and we don't want to
		 * get stuck waiting for that to complete.  So, we want to check
		 * to see if we can lock the dquot's buffer without sleeping.
		 * If we can and it is marked for delayed write, then we
		 * hold it and send it out from the push routine.  We don't
		 * want to do that now since we might sleep in the device
		 * strategy routine.  We also don't want to grab the buffer lock
		 * here because we'd like not to call into the buffer cache
		 * while holding the AIL_LOCK.
		 * Make sure to only return PUSHBUF if we set pushbuf_flag
		 * ourselves.  If someone else is doing it then we don't
		 * want to go to the push routine and duplicate their efforts.
		 */
		if (qip->qli_pushbuf_flag == 0) {
			qip->qli_pushbuf_flag = 1;
			ASSERT(qip->qli_format.qlf_blkno == dqp->q_blkno);
#ifdef DEBUG
			qip->qli_push_owner = current_pid();
#endif
			/*
			 * The dquot is left locked.
			 */
			retval = XFS_ITEM_PUSHBUF;
		} else {
			retval = XFS_ITEM_FLUSHING;
			xfs_dqunlock_nonotify(dqp);
		}
	}

	ASSERT(qip->qli_item.li_flags & XFS_LI_IN_AIL);
	return (retval);
}


/*
 * Unlock the dquot associated with the log item.
 * Clear the fields of the dquot and dquot log item that
 * are specific to the current transaction.  If the
 * hold flags is set, do not unlock the dquot.
 */
STATIC void
xfs_qm_dquot_logitem_unlock(
	xfs_dq_logitem_t    *ql)
{
	xfs_dquot_t	*dqp;

	ASSERT(ql != NULL);
	dqp = ql->qli_dquot;
	ASSERT(XFS_DQ_IS_LOCKED(dqp));

	/*
	 * Clear the transaction pointer in the dquot
	 */
	dqp->q_transp = NULL;

	/*
	 * dquots are never 'held' from getting unlocked at the end of
	 * a transaction.  Their locking and unlocking is hidden inside the
	 * transaction layer, within trans_commit. Hence, no LI_HOLD flag
	 * for the logitem.
	 */
	xfs_dqunlock(dqp);
}


/*
 * this needs to stamp an lsn into the dquot, I think.
 * rpc's that look at user dquot's would then have to
 * push on the dependency recorded in the dquot
 */
/* ARGSUSED */
STATIC void
xfs_qm_dquot_logitem_committing(
	xfs_dq_logitem_t	*l,
	xfs_lsn_t		lsn)
{
	return;
}


/*
 * This is the ops vector for dquots
 */
static struct xfs_item_ops xfs_dquot_item_ops = {
	.iop_size	= (uint(*)(xfs_log_item_t*))xfs_qm_dquot_logitem_size,
	.iop_format	= (void(*)(xfs_log_item_t*, xfs_log_iovec_t*))
					xfs_qm_dquot_logitem_format,
	.iop_pin	= (void(*)(xfs_log_item_t*))xfs_qm_dquot_logitem_pin,
	.iop_unpin	= (void(*)(xfs_log_item_t*, int))
					xfs_qm_dquot_logitem_unpin,
	.iop_unpin_remove = (void(*)(xfs_log_item_t*, xfs_trans_t*))
					xfs_qm_dquot_logitem_unpin_remove,
	.iop_trylock	= (uint(*)(xfs_log_item_t*))
					xfs_qm_dquot_logitem_trylock,
	.iop_unlock	= (void(*)(xfs_log_item_t*))xfs_qm_dquot_logitem_unlock,
	.iop_committed	= (xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t))
					xfs_qm_dquot_logitem_committed,
	.iop_push	= (void(*)(xfs_log_item_t*))xfs_qm_dquot_logitem_push,
	.iop_pushbuf	= (void(*)(xfs_log_item_t*))
					xfs_qm_dquot_logitem_pushbuf,
	.iop_committing = (void(*)(xfs_log_item_t*, xfs_lsn_t))
					xfs_qm_dquot_logitem_committing
};

/*
 * Initialize the dquot log item for a newly allocated dquot.
 * The dquot isn't locked at this point, but it isn't on any of the lists
 * either, so we don't care.
 */
void
xfs_qm_dquot_logitem_init(
	struct xfs_dquot *dqp)
{
	xfs_dq_logitem_t  *lp;
	lp = &dqp->q_logitem;

	lp->qli_item.li_type = XFS_LI_DQUOT;
	lp->qli_item.li_ops = &xfs_dquot_item_ops;
	lp->qli_item.li_mountp = dqp->q_mount;
	lp->qli_dquot = dqp;
	lp->qli_format.qlf_type = XFS_LI_DQUOT;
	lp->qli_format.qlf_id = be32_to_cpu(dqp->q_core.d_id);
	lp->qli_format.qlf_blkno = dqp->q_blkno;
	lp->qli_format.qlf_len = 1;
	/*
	 * This is just the offset of this dquot within its buffer
	 * (which is currently 1 FSB and probably won't change).
	 * Hence 32 bits for this offset should be just fine.
	 * Alternatively, we can store (bufoffset / sizeof(xfs_dqblk_t))
	 * here, and recompute it at recovery time.
	 */
	lp->qli_format.qlf_boffset = (__uint32_t)dqp->q_bufoffset;
}

/*------------------  QUOTAOFF LOG ITEMS  -------------------*/

/*
 * This returns the number of iovecs needed to log the given quotaoff item.
 * We only need 1 iovec for an quotaoff item.  It just logs the
 * quotaoff_log_format structure.
 */
/*ARGSUSED*/
STATIC uint
xfs_qm_qoff_logitem_size(xfs_qoff_logitem_t *qf)
{
	return (1);
}

/*
 * This is called to fill in the vector of log iovecs for the
 * given quotaoff log item. We use only 1 iovec, and we point that
 * at the quotaoff_log_format structure embedded in the quotaoff item.
 * It is at this point that we assert that all of the extent
 * slots in the quotaoff item have been filled.
 */
STATIC void
xfs_qm_qoff_logitem_format(xfs_qoff_logitem_t	*qf,
			   xfs_log_iovec_t	*log_vector)
{
	ASSERT(qf->qql_format.qf_type == XFS_LI_QUOTAOFF);

	log_vector->i_addr = (xfs_caddr_t)&(qf->qql_format);
	log_vector->i_len = sizeof(xfs_qoff_logitem_t);
	XLOG_VEC_SET_TYPE(log_vector, XLOG_REG_TYPE_QUOTAOFF);
	qf->qql_format.qf_size = 1;
}


/*
 * Pinning has no meaning for an quotaoff item, so just return.
 */
/*ARGSUSED*/
STATIC void
xfs_qm_qoff_logitem_pin(xfs_qoff_logitem_t *qf)
{
	return;
}


/*
 * Since pinning has no meaning for an quotaoff item, unpinning does
 * not either.
 */
/*ARGSUSED*/
STATIC void
xfs_qm_qoff_logitem_unpin(xfs_qoff_logitem_t *qf, int stale)
{
	return;
}

/*ARGSUSED*/
STATIC void
xfs_qm_qoff_logitem_unpin_remove(xfs_qoff_logitem_t *qf, xfs_trans_t *tp)
{
	return;
}

/*
 * Quotaoff items have no locking, so just return success.
 */
/*ARGSUSED*/
STATIC uint
xfs_qm_qoff_logitem_trylock(xfs_qoff_logitem_t *qf)
{
	return XFS_ITEM_LOCKED;
}

/*
 * Quotaoff items have no locking or pushing, so return failure
 * so that the caller doesn't bother with us.
 */
/*ARGSUSED*/
STATIC void
xfs_qm_qoff_logitem_unlock(xfs_qoff_logitem_t *qf)
{
	return;
}

/*
 * The quotaoff-start-item is logged only once and cannot be moved in the log,
 * so simply return the lsn at which it's been logged.
 */
/*ARGSUSED*/
STATIC xfs_lsn_t
xfs_qm_qoff_logitem_committed(xfs_qoff_logitem_t *qf, xfs_lsn_t lsn)
{
	return (lsn);
}

/*
 * There isn't much you can do to push on an quotaoff item.  It is simply
 * stuck waiting for the log to be flushed to disk.
 */
/*ARGSUSED*/
STATIC void
xfs_qm_qoff_logitem_push(xfs_qoff_logitem_t *qf)
{
	return;
}


/*ARGSUSED*/
STATIC xfs_lsn_t
xfs_qm_qoffend_logitem_committed(
	xfs_qoff_logitem_t *qfe,
	xfs_lsn_t lsn)
{
	xfs_qoff_logitem_t	*qfs;
	SPLDECL(s);

	qfs = qfe->qql_start_lip;
	AIL_LOCK(qfs->qql_item.li_mountp,s);
	/*
	 * Delete the qoff-start logitem from the AIL.
	 * xfs_trans_delete_ail() drops the AIL lock.
	 */
	xfs_trans_delete_ail(qfs->qql_item.li_mountp, (xfs_log_item_t *)qfs, s);
	kmem_free(qfs, sizeof(xfs_qoff_logitem_t));
	kmem_free(qfe, sizeof(xfs_qoff_logitem_t));
	return (xfs_lsn_t)-1;
}

/*
 * XXX rcc - don't know quite what to do with this.  I think we can
 * just ignore it.  The only time that isn't the case is if we allow
 * the client to somehow see that quotas have been turned off in which
 * we can't allow that to get back until the quotaoff hits the disk.
 * So how would that happen?  Also, do we need different routines for
 * quotaoff start and quotaoff end?  I suspect the answer is yes but
 * to be sure, I need to look at the recovery code and see how quota off
 * recovery is handled (do we roll forward or back or do something else).
 * If we roll forwards or backwards, then we need two separate routines,
 * one that does nothing and one that stamps in the lsn that matters
 * (truly makes the quotaoff irrevocable).  If we do something else,
 * then maybe we don't need two.
 */
/* ARGSUSED */
STATIC void
xfs_qm_qoff_logitem_committing(xfs_qoff_logitem_t *qip, xfs_lsn_t commit_lsn)
{
	return;
}

/* ARGSUSED */
STATIC void
xfs_qm_qoffend_logitem_committing(xfs_qoff_logitem_t *qip, xfs_lsn_t commit_lsn)
{
	return;
}

static struct xfs_item_ops xfs_qm_qoffend_logitem_ops = {
	.iop_size	= (uint(*)(xfs_log_item_t*))xfs_qm_qoff_logitem_size,
	.iop_format	= (void(*)(xfs_log_item_t*, xfs_log_iovec_t*))
					xfs_qm_qoff_logitem_format,
	.iop_pin	= (void(*)(xfs_log_item_t*))xfs_qm_qoff_logitem_pin,
	.iop_unpin	= (void(*)(xfs_log_item_t* ,int))
					xfs_qm_qoff_logitem_unpin,
	.iop_unpin_remove = (void(*)(xfs_log_item_t*,xfs_trans_t*))
					xfs_qm_qoff_logitem_unpin_remove,
	.iop_trylock	= (uint(*)(xfs_log_item_t*))xfs_qm_qoff_logitem_trylock,
	.iop_unlock	= (void(*)(xfs_log_item_t*))xfs_qm_qoff_logitem_unlock,
	.iop_committed	= (xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t))
					xfs_qm_qoffend_logitem_committed,
	.iop_push	= (void(*)(xfs_log_item_t*))xfs_qm_qoff_logitem_push,
	.iop_pushbuf	= NULL,
	.iop_committing = (void(*)(xfs_log_item_t*, xfs_lsn_t))
					xfs_qm_qoffend_logitem_committing
};

/*
 * This is the ops vector shared by all quotaoff-start log items.
 */
static struct xfs_item_ops xfs_qm_qoff_logitem_ops = {
	.iop_size	= (uint(*)(xfs_log_item_t*))xfs_qm_qoff_logitem_size,
	.iop_format	= (void(*)(xfs_log_item_t*, xfs_log_iovec_t*))
					xfs_qm_qoff_logitem_format,
	.iop_pin	= (void(*)(xfs_log_item_t*))xfs_qm_qoff_logitem_pin,
	.iop_unpin	= (void(*)(xfs_log_item_t*, int))
					xfs_qm_qoff_logitem_unpin,
	.iop_unpin_remove = (void(*)(xfs_log_item_t*,xfs_trans_t*))
					xfs_qm_qoff_logitem_unpin_remove,
	.iop_trylock	= (uint(*)(xfs_log_item_t*))xfs_qm_qoff_logitem_trylock,
	.iop_unlock	= (void(*)(xfs_log_item_t*))xfs_qm_qoff_logitem_unlock,
	.iop_committed	= (xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t))
					xfs_qm_qoff_logitem_committed,
	.iop_push	= (void(*)(xfs_log_item_t*))xfs_qm_qoff_logitem_push,
	.iop_pushbuf	= NULL,
	.iop_committing = (void(*)(xfs_log_item_t*, xfs_lsn_t))
					xfs_qm_qoff_logitem_committing
};

/*
 * Allocate and initialize an quotaoff item of the correct quota type(s).
 */
xfs_qoff_logitem_t *
xfs_qm_qoff_logitem_init(
	struct xfs_mount *mp,
	xfs_qoff_logitem_t *start,
	uint flags)
{
	xfs_qoff_logitem_t	*qf;

	qf = (xfs_qoff_logitem_t*) kmem_zalloc(sizeof(xfs_qoff_logitem_t), KM_SLEEP);

	qf->qql_item.li_type = XFS_LI_QUOTAOFF;
	if (start)
		qf->qql_item.li_ops = &xfs_qm_qoffend_logitem_ops;
	else
		qf->qql_item.li_ops = &xfs_qm_qoff_logitem_ops;
	qf->qql_item.li_mountp = mp;
	qf->qql_format.qf_type = XFS_LI_QUOTAOFF;
	qf->qql_format.qf_flags = flags;
	qf->qql_start_lip = start;
	return (qf);
}