xfs_dquot_item.c

linux-2.4.29操作系统的源码

/*
 * 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 version 2 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.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.	 Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_alloc.h"
#include "xfs_dmapi.h"
#include "xfs_quota.h"
#include "xfs_mount.h"
#include "xfs_alloc_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_attr_sf.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_bmap.h"
#include "xfs_bit.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);
	logvec++;
	logvec->i_addr = (xfs_caddr_t)&logitem->qli_dquot->q_core;
	logvec->i_len  = sizeof(xfs_disk_dquot_t);

	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 buffercache 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 == get_thread_id());

	/*
	 * 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 ((valusema(&(dqp->q_flock)) > 0)  ||
	    ((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) &&
				  (valusema(&(dqp->q_flock)) <= 0));
			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 = get_thread_id();
#endif
			/*
			 * The dquot is left locked.
			 */
			retval = XFS_ITEM_PUSHBUF;