patch-2.4.25 linux-2.4.25/fs/xfs/quota/xfs_qm.c

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diff -urN linux-2.4.24/fs/xfs/quota/xfs_qm.c linux-2.4.25/fs/xfs/quota/xfs_qm.c
@@ -0,0 +1,2819 @@
+/*
+ * Copyright (c) 2000-2002 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_clnt.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_space.h"
+#include "xfs_utils.h"
+
+#include "xfs_qm.h"
+
+/*
+ * The global quota manager. There is only one of these for the entire
+ * system, _not_ one per file system. XQM keeps track of the overall
+ * quota functionality, including maintaining the freelist and hash
+ * tables of dquots.
+ */
+mutex_t xfs_Gqm_lock;
+struct xfs_qm	*xfs_Gqm;
+
+kmem_zone_t	*qm_dqzone;
+kmem_zone_t	*qm_dqtrxzone;
+kmem_shaker_t	xfs_qm_shaker;
+
+STATIC void	xfs_qm_list_init(xfs_dqlist_t *, char *, int);
+STATIC void	xfs_qm_list_destroy(xfs_dqlist_t *);
+STATIC int	xfs_qm_quotacheck(xfs_mount_t *);
+
+STATIC int	xfs_qm_init_quotainos(xfs_mount_t *);
+STATIC int	xfs_qm_shake(int, unsigned int);
+
+#ifdef DEBUG
+extern mutex_t	qcheck_lock;
+#endif
+
+#ifdef QUOTADEBUG
+#define XQM_LIST_PRINT(l, NXT, title) \
+{ \
+	xfs_dquot_t	*dqp; int i = 0; \
+	cmn_err(CE_DEBUG, "%s (#%d)", title, (int) (l)->qh_nelems); \
+	for (dqp = (l)->qh_next; dqp != NULL; dqp = dqp->NXT) { \
+		cmn_err(CE_DEBUG, "   %d.  \"%d (%s)\"   " \
+				  "bcnt = %d, icnt = %d, refs = %d", \
+			++i, (int) INT_GET(dqp->q_core.d_id, ARCH_CONVERT), \
+			DQFLAGTO_TYPESTR(dqp),	     \
+			(int) INT_GET(dqp->q_core.d_bcount, ARCH_CONVERT), \
+			(int) INT_GET(dqp->q_core.d_icount, ARCH_CONVERT), \
+			(int) dqp->q_nrefs);  } \
+}
+#else
+#define XQM_LIST_PRINT(l, NXT, title) do { } while (0)
+#endif
+
+/*
+ * Initialize the XQM structure.
+ * Note that there is not one quota manager per file system.
+ */
+STATIC struct xfs_qm *
+xfs_Gqm_init(void)
+{
+	xfs_qm_t		*xqm;
+	int			hsize, i;
+
+	xqm = kmem_zalloc(sizeof(xfs_qm_t), KM_SLEEP);
+	ASSERT(xqm);
+
+	/*
+	 * Initialize the dquot hash tables.
+	 */
+	hsize = (DQUOT_HASH_HEURISTIC < XFS_QM_NCSIZE_THRESHOLD) ?
+		XFS_QM_HASHSIZE_LOW : XFS_QM_HASHSIZE_HIGH;
+	xqm->qm_dqhashmask = hsize - 1;
+
+	xqm->qm_usr_dqhtable = (xfs_dqhash_t *)kmem_zalloc(hsize *
+						      sizeof(xfs_dqhash_t),
+						      KM_SLEEP);
+	xqm->qm_grp_dqhtable = (xfs_dqhash_t *)kmem_zalloc(hsize *
+						      sizeof(xfs_dqhash_t),
+						      KM_SLEEP);
+	ASSERT(xqm->qm_usr_dqhtable != NULL);
+	ASSERT(xqm->qm_grp_dqhtable != NULL);
+
+	for (i = 0; i < hsize; i++) {
+		xfs_qm_list_init(&(xqm->qm_usr_dqhtable[i]), "uxdqh", i);
+		xfs_qm_list_init(&(xqm->qm_grp_dqhtable[i]), "gxdqh", i);
+	}
+
+	/*
+	 * Freelist of all dquots of all file systems
+	 */
+	xfs_qm_freelist_init(&(xqm->qm_dqfreelist));
+
+	/*
+	 * dquot zone. we register our own low-memory callback.
+	 */
+	if (!qm_dqzone) {
+		xqm->qm_dqzone = kmem_zone_init(sizeof(xfs_dquot_t),
+						"xfs_dquots");
+		qm_dqzone = xqm->qm_dqzone;
+	} else
+		xqm->qm_dqzone = qm_dqzone;
+
+	xfs_qm_shaker = kmem_shake_register(xfs_qm_shake);
+
+	/*
+	 * The t_dqinfo portion of transactions.
+	 */
+	if (!qm_dqtrxzone) {
+		xqm->qm_dqtrxzone = kmem_zone_init(sizeof(xfs_dquot_acct_t),
+						   "xfs_dqtrx");
+		qm_dqtrxzone = xqm->qm_dqtrxzone;
+	} else
+		xqm->qm_dqtrxzone = qm_dqtrxzone;
+
+	atomic_set(&xqm->qm_totaldquots, 0);
+	xqm->qm_dqfree_ratio = XFS_QM_DQFREE_RATIO;
+	xqm->qm_nrefs = 0;
+#ifdef DEBUG
+	mutex_init(&qcheck_lock, MUTEX_DEFAULT, "qchk");
+#endif
+	return xqm;
+}
+
+/*
+ * Destroy the global quota manager when its reference count goes to zero.
+ */
+void
+xfs_qm_destroy(
+	struct xfs_qm	*xqm)
+{
+	int		hsize, i;
+
+	ASSERT(xqm != NULL);
+	ASSERT(xqm->qm_nrefs == 0);
+	kmem_shake_deregister(xfs_qm_shaker);
+	hsize = xqm->qm_dqhashmask + 1;
+	for (i = 0; i < hsize; i++) {
+		xfs_qm_list_destroy(&(xqm->qm_usr_dqhtable[i]));
+		xfs_qm_list_destroy(&(xqm->qm_grp_dqhtable[i]));
+	}
+	kmem_free(xqm->qm_usr_dqhtable, hsize * sizeof(xfs_dqhash_t));
+	kmem_free(xqm->qm_grp_dqhtable, hsize * sizeof(xfs_dqhash_t));
+	xqm->qm_usr_dqhtable = NULL;
+	xqm->qm_grp_dqhtable = NULL;
+	xqm->qm_dqhashmask = 0;
+	xfs_qm_freelist_destroy(&(xqm->qm_dqfreelist));
+#ifdef DEBUG
+	mutex_destroy(&qcheck_lock);
+#endif
+	kmem_free(xqm, sizeof(xfs_qm_t));
+}
+
+/*
+ * Called at mount time to let XQM know that another file system is
+ * starting quotas. This isn't crucial information as the individual mount
+ * structures are pretty independent, but it helps the XQM keep a
+ * global view of what's going on.
+ */
+/* ARGSUSED */
+STATIC int
+xfs_qm_hold_quotafs_ref(
+	struct xfs_mount *mp)
+{
+	/*
+	 * Need to lock the xfs_Gqm structure for things like this. For example,
+	 * the structure could disappear between the entry to this routine and
+	 * a HOLD operation if not locked.
+	 */
+	XFS_QM_LOCK(xfs_Gqm);
+
+	if (xfs_Gqm == NULL) {
+		if ((xfs_Gqm = xfs_Gqm_init()) == NULL) {
+			return (XFS_ERROR(EINVAL));
+		}
+	}
+	/*
+	 * We can keep a list of all filesystems with quotas mounted for
+	 * debugging and statistical purposes, but ...
+	 * Just take a reference and get out.
+	 */
+	XFS_QM_HOLD(xfs_Gqm);
+	XFS_QM_UNLOCK(xfs_Gqm);
+
+	return 0;
+}
+
+
+/*
+ * Release the reference that a filesystem took at mount time,
+ * so that we know when we need to destroy the entire quota manager.
+ */
+/* ARGSUSED */
+STATIC void
+xfs_qm_rele_quotafs_ref(
+	struct xfs_mount *mp)
+{
+	xfs_dquot_t	*dqp, *nextdqp;
+
+	ASSERT(xfs_Gqm);
+	ASSERT(xfs_Gqm->qm_nrefs > 0);
+
+	/*
+	 * Go thru the freelist and destroy all inactive dquots.
+	 */
+	xfs_qm_freelist_lock(xfs_Gqm);
+
+	for (dqp = xfs_Gqm->qm_dqfreelist.qh_next;
+	     dqp != (xfs_dquot_t *)&(xfs_Gqm->qm_dqfreelist); ) {
+		xfs_dqlock(dqp);
+		nextdqp = dqp->dq_flnext;
+		if (dqp->dq_flags & XFS_DQ_INACTIVE) {
+			ASSERT(dqp->q_mount == NULL);
+			ASSERT(! XFS_DQ_IS_DIRTY(dqp));
+			ASSERT(dqp->HL_PREVP == NULL);
+			ASSERT(dqp->MPL_PREVP == NULL);
+			XQM_FREELIST_REMOVE(dqp);
+			xfs_dqunlock(dqp);
+			xfs_qm_dqdestroy(dqp);
+		} else {
+			xfs_dqunlock(dqp);
+		}
+		dqp = nextdqp;
+	}
+	xfs_qm_freelist_unlock(xfs_Gqm);
+
+	/*
+	 * Destroy the entire XQM. If somebody mounts with quotaon, this'll
+	 * be restarted.
+	 */
+	XFS_QM_LOCK(xfs_Gqm);
+	XFS_QM_RELE(xfs_Gqm);
+	if (xfs_Gqm->qm_nrefs == 0) {
+		xfs_qm_destroy(xfs_Gqm);
+		xfs_Gqm = NULL;
+	}
+	XFS_QM_UNLOCK(xfs_Gqm);
+}
+
+/*
+ * This is called at mount time from xfs_mountfs to initialize the quotainfo
+ * structure and start the global quotamanager (xfs_Gqm) if it hasn't done
+ * so already.	Note that the superblock has not been read in yet.
+ */
+void
+xfs_qm_mount_quotainit(
+	xfs_mount_t	*mp,
+	uint		flags)
+{
+	/*
+	 * User or group quotas has to be on.
+	 */
+	ASSERT(flags & (XFSMNT_UQUOTA | XFSMNT_GQUOTA));
+
+	/*
+	 * Initialize the flags in the mount structure. From this point
+	 * onwards we look at m_qflags to figure out if quotas's ON/OFF, etc.
+	 * Note that we enforce nothing if accounting is off.
+	 * ie.	XFSMNT_*QUOTA must be ON for XFSMNT_*QUOTAENF.
+	 * It isn't necessary to take the quotaoff lock to do this; this is
+	 * called from mount.
+	 */
+	if (flags & XFSMNT_UQUOTA) {
+		mp->m_qflags |= (XFS_UQUOTA_ACCT | XFS_UQUOTA_ACTIVE);
+		if (flags & XFSMNT_UQUOTAENF)
+			mp->m_qflags |= XFS_UQUOTA_ENFD;
+	}
+	if (flags & XFSMNT_GQUOTA) {
+		mp->m_qflags |= (XFS_GQUOTA_ACCT | XFS_GQUOTA_ACTIVE);
+		if (flags & XFSMNT_GQUOTAENF)
+			mp->m_qflags |= XFS_GQUOTA_ENFD;
+	}
+}
+
+/*
+ * Just destroy the quotainfo structure.
+ */
+void
+xfs_qm_unmount_quotadestroy(
+	xfs_mount_t	*mp)
+{
+	if (mp->m_quotainfo)
+		xfs_qm_destroy_quotainfo(mp);
+}
+
+
+/*
+ * This is called from xfs_mountfs to start quotas and initialize all
+ * necessary data structures like quotainfo.  This is also responsible for
+ * running a quotacheck as necessary.  We are guaranteed that the superblock
+ * is consistently read in at this point.
+ */
+int
+xfs_qm_mount_quotas(
+	xfs_mount_t	*mp)
+{
+	unsigned long	s;
+	int		error = 0;
+	uint		sbf;
+
+	/*
+	 * If a file system had quotas running earlier, but decided to
+	 * mount without -o quota/uquota/gquota options, revoke the
+	 * quotachecked license, and bail out.
+	 */
+	if (! XFS_IS_QUOTA_ON(mp) &&
+	    (mp->m_sb.sb_qflags & (XFS_UQUOTA_ACCT|XFS_GQUOTA_ACCT))) {
+		mp->m_qflags = 0;
+		goto write_changes;
+	}
+
+	/*
+	 * If quotas on realtime volumes is not supported, we disable
+	 * quotas immediately.
+	 */
+	if (mp->m_sb.sb_rextents) {
+		cmn_err(CE_NOTE,
+			"Cannot turn on quotas for realtime filesystem %s",
+			mp->m_fsname);
+		mp->m_qflags = 0;
+		goto write_changes;
+	}
+
+#if defined(DEBUG) && defined(XFS_LOUD_RECOVERY)
+	cmn_err(CE_NOTE, "Attempting to turn on disk quotas.");
+#endif
+
+	ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+	/*
+	 * Allocate the quotainfo structure inside the mount struct, and
+	 * create quotainode(s), and change/rev superblock if necessary.
+	 */
+	if ((error = xfs_qm_init_quotainfo(mp))) {
+		/*
+		 * We must turn off quotas.
+		 */
+		ASSERT(mp->m_quotainfo == NULL);
+		mp->m_qflags = 0;
+		goto write_changes;
+	}
+	/*
+	 * If any of the quotas are not consistent, do a quotacheck.
+	 */
+	if (XFS_QM_NEED_QUOTACHECK(mp)) {
+#ifdef DEBUG
+		cmn_err(CE_NOTE, "Doing a quotacheck. Please wait.");
+#endif
+		if ((error = xfs_qm_quotacheck(mp))) {
+			cmn_err(CE_WARN, "Quotacheck unsuccessful (Error %d): "
+				"Disabling quotas.",
+				error);
+			/*
+			 * We must turn off quotas.
+			 */
+			ASSERT(mp->m_quotainfo != NULL);
+			ASSERT(xfs_Gqm != NULL);
+			xfs_qm_destroy_quotainfo(mp);
+			mp->m_qflags = 0;
+			goto write_changes;
+		}
+#ifdef DEBUG
+		cmn_err(CE_NOTE, "Done quotacheck.");
+#endif
+	}
+ write_changes:
+	/*
+	 * We actually don't have to acquire the SB_LOCK at all.
+	 * This can only be called from mount, and that's single threaded. XXX
+	 */
+	s = XFS_SB_LOCK(mp);
+	sbf = mp->m_sb.sb_qflags;
+	mp->m_sb.sb_qflags = mp->m_qflags & XFS_MOUNT_QUOTA_ALL;
+	XFS_SB_UNLOCK(mp, s);
+
+	if (sbf != (mp->m_qflags & XFS_MOUNT_QUOTA_ALL)) {
+		if (xfs_qm_write_sb_changes(mp, XFS_SB_QFLAGS)) {
+			/*
+			 * We could only have been turning quotas off.
+			 * We aren't in very good shape actually because
+			 * the incore structures are convinced that quotas are
+			 * off, but the on disk superblock doesn't know that !
+			 */
+			ASSERT(!(XFS_IS_QUOTA_RUNNING(mp)));
+			xfs_fs_cmn_err(CE_ALERT, mp,
+				"XFS mount_quotas: Superblock update failed!");
+		}
+	}
+
+	if (error) {
+		xfs_fs_cmn_err(CE_WARN, mp,
+			"Failed to initialize disk quotas.");
+	}
+	return XFS_ERROR(error);
+}
+
+/*
+ * Called from the vfsops layer.
+ */
+int
+xfs_qm_unmount_quotas(
+	xfs_mount_t	*mp)
+{
+	xfs_inode_t	*uqp, *gqp;
+	int		error = 0;
+
+	/*
+	 * Release the dquots that root inode, et al might be holding,
+	 * before we flush quotas and blow away the quotainfo structure.
+	 */
+	ASSERT(mp->m_rootip);
+	xfs_qm_dqdetach(mp->m_rootip);
+	if (mp->m_rbmip)
+		xfs_qm_dqdetach(mp->m_rbmip);
+	if (mp->m_rsumip)
+		xfs_qm_dqdetach(mp->m_rsumip);
+
+	/*
+	 * Flush out the quota inodes.
+	 */
+	uqp = gqp = NULL;
+	if (mp->m_quotainfo) {
+		if ((uqp = mp->m_quotainfo->qi_uquotaip) != NULL) {
+			xfs_ilock(uqp, XFS_ILOCK_EXCL);
+			xfs_iflock(uqp);
+			error = xfs_iflush(uqp, XFS_IFLUSH_SYNC);
+			xfs_iunlock(uqp, XFS_ILOCK_EXCL);
+			if (unlikely(error == EFSCORRUPTED)) {
+				XFS_ERROR_REPORT("xfs_qm_unmount_quotas(1)",
+						 XFS_ERRLEVEL_LOW, mp);
+				goto out;
+			}
+		}
+		if ((gqp = mp->m_quotainfo->qi_gquotaip) != NULL) {
+			xfs_ilock(gqp, XFS_ILOCK_EXCL);
+			xfs_iflock(gqp);
+			error = xfs_iflush(gqp, XFS_IFLUSH_SYNC);
+			xfs_iunlock(gqp, XFS_ILOCK_EXCL);
+			if (unlikely(error == EFSCORRUPTED)) {
+				XFS_ERROR_REPORT("xfs_qm_unmount_quotas(2)",
+						 XFS_ERRLEVEL_LOW, mp);
+				goto out;
+			}
+		}
+	}
+	if (uqp) {
+		 XFS_PURGE_INODE(uqp);
+		 mp->m_quotainfo->qi_uquotaip = NULL;
+	}
+	if (gqp) {
+		XFS_PURGE_INODE(gqp);
+		mp->m_quotainfo->qi_gquotaip = NULL;
+	}
+out:
+	return XFS_ERROR(error);
+}
+
+/*
+ * Flush all dquots of the given file system to disk. The dquots are
+ * _not_ purged from memory here, just their data written to disk.
+ */
+int
+xfs_qm_dqflush_all(
+	xfs_mount_t	*mp,
+	int		flags)
+{
+	int		recl;
+	xfs_dquot_t	*dqp;
+	int		niters;
+	int		error;
+
+	if (mp->m_quotainfo == NULL)
+		return (0);
+	niters = 0;
+again:
+	xfs_qm_mplist_lock(mp);
+	FOREACH_DQUOT_IN_MP(dqp, mp) {
+		xfs_dqlock(dqp);
+		if (! XFS_DQ_IS_DIRTY(dqp)) {
+			xfs_dqunlock(dqp);
+			continue;
+		}
+		xfs_dqtrace_entry(dqp, "FLUSHALL: DQDIRTY");
+		/* XXX a sentinel would be better */
+		recl = XFS_QI_MPLRECLAIMS(mp);
+		if (! xfs_qm_dqflock_nowait(dqp)) {
+			/*
+			 * If we can't grab the flush lock then check
+			 * to see if the dquot has been flushed delayed
+			 * write.  If so, grab its buffer and send it
+			 * out immediately.  We'll be able to acquire
+			 * the flush lock when the I/O completes.
+			 */
+			xfs_qm_dqflock_pushbuf_wait(dqp);
+		}
+		/*
+		 * Let go of the mplist lock. We don't want to hold it
+		 * across a disk write.
+		 */
+		xfs_qm_mplist_unlock(mp);
+		error = xfs_qm_dqflush(dqp, flags);
+		xfs_dqunlock(dqp);
+		if (error)
+			return (error);
+
+		xfs_qm_mplist_lock(mp);
+		if (recl != XFS_QI_MPLRECLAIMS(mp)) {
+			xfs_qm_mplist_unlock(mp);
+			/* XXX restart limit */
+			goto again;
+		}
+	}
+
+	xfs_qm_mplist_unlock(mp);
+	/* return ! busy */
+	return (0);
+}
+/*
+ * Release the group dquot pointers the user dquots may be
+ * carrying around as a hint. mplist is locked on entry and exit.
+ */
+STATIC void
+xfs_qm_detach_gdquots(
+	xfs_mount_t	*mp)
+{
+	xfs_dquot_t	*dqp, *gdqp;
+	int		nrecl;
+
+ again:
+	ASSERT(XFS_QM_IS_MPLIST_LOCKED(mp));
+	dqp = XFS_QI_MPLNEXT(mp);
+	while (dqp) {
+		xfs_dqlock(dqp);
+		if ((gdqp = dqp->q_gdquot)) {
+			xfs_dqlock(gdqp);
+			dqp->q_gdquot = NULL;
+		}
+		xfs_dqunlock(dqp);
+
+		if (gdqp) {
+			/*
+			 * Can't hold the mplist lock across a dqput.
+			 * XXXmust convert to marker based iterations here.
+			 */
+			nrecl = XFS_QI_MPLRECLAIMS(mp);
+			xfs_qm_mplist_unlock(mp);
+			xfs_qm_dqput(gdqp);
+
+			xfs_qm_mplist_lock(mp);
+			if (nrecl != XFS_QI_MPLRECLAIMS(mp))
+				goto again;
+		}
+		dqp = dqp->MPL_NEXT;
+	}
+}
+
+/*
+ * Go through all the incore dquots of this file system and take them
+ * off the mplist and hashlist, if the dquot type matches the dqtype
+ * parameter. This is used when turning off quota accounting for
+ * users and/or groups, as well as when the filesystem is unmounting.
+ */
+STATIC int
+xfs_qm_dqpurge_int(
+	xfs_mount_t	*mp,
+	uint		flags) /* QUOTAOFF/UMOUNTING/UQUOTA/GQUOTA */
+{
+	xfs_dquot_t	*dqp;
+	uint		dqtype;
+	int		nrecl;
+	xfs_dquot_t	*nextdqp;
+	int		nmisses;
+
+	if (mp->m_quotainfo == NULL)
+		return (0);
+
+	dqtype = (flags & XFS_QMOPT_UQUOTA) ? XFS_DQ_USER : 0;
+	dqtype |= (flags & XFS_QMOPT_GQUOTA) ? XFS_DQ_GROUP : 0;
+
+	xfs_qm_mplist_lock(mp);
+
+	/*
+	 * In the first pass through all incore dquots of this filesystem,
+	 * we release the group dquot pointers the user dquots may be
+	 * carrying around as a hint. We need to do this irrespective of
+	 * what's being turned off.
+	 */
+	xfs_qm_detach_gdquots(mp);
+
+      again:
+	nmisses = 0;
+	ASSERT(XFS_QM_IS_MPLIST_LOCKED(mp));
+	/*
+	 * Try to get rid of all of the unwanted dquots. The idea is to
+	 * get them off mplist and hashlist, but leave them on freelist.
+	 */
+	dqp = XFS_QI_MPLNEXT(mp);
+	while (dqp) {
+		/*
+		 * It's OK to look at the type without taking dqlock here.
+		 * We're holding the mplist lock here, and that's needed for
+		 * a dqreclaim.
+		 */
+		if ((dqp->dq_flags & dqtype) == 0) {
+			dqp = dqp->MPL_NEXT;
+			continue;
+		}
+
+		if (! xfs_qm_dqhashlock_nowait(dqp)) {
+			nrecl = XFS_QI_MPLRECLAIMS(mp);
+			xfs_qm_mplist_unlock(mp);
+			XFS_DQ_HASH_LOCK(dqp->q_hash);
+			xfs_qm_mplist_lock(mp);
+
+			/*
+			 * XXXTheoretically, we can get into a very long
+			 * ping pong game here.
+			 * No one can be adding dquots to the mplist at
+			 * this point, but somebody might be taking things off.
+			 */
+			if (nrecl != XFS_QI_MPLRECLAIMS(mp)) {
+				XFS_DQ_HASH_UNLOCK(dqp->q_hash);
+				goto again;
+			}
+		}
+
+		/*
+		 * Take the dquot off the mplist and hashlist. It may remain on
+		 * freelist in INACTIVE state.
+		 */
+		nextdqp = dqp->MPL_NEXT;
+		nmisses += xfs_qm_dqpurge(dqp, flags);
+		dqp = nextdqp;
+	}
+	xfs_qm_mplist_unlock(mp);
+	return nmisses;
+}
+
+int
+xfs_qm_dqpurge_all(
+	xfs_mount_t	*mp,
+	uint		flags)
+{
+	int		ndquots;
+
+	/*
+	 * Purge the dquot cache.
+	 * None of the dquots should really be busy at this point.
+	 */
+	if (mp->m_quotainfo) {
+		while ((ndquots = xfs_qm_dqpurge_int(mp, flags))) {
+			delay(ndquots * 10);
+		}
+	}
+	return 0;
+}
+
+STATIC int
+xfs_qm_dqattach_one(
+	xfs_inode_t	*ip,
+	xfs_dqid_t	id,
+	uint		type,
+	uint		doalloc,
+	uint		dolock,
+	xfs_dquot_t	*udqhint, /* hint */
+	xfs_dquot_t	**IO_idqpp)
+{
+	xfs_dquot_t	*dqp;
+	int		error;
+
+	ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
+	error = 0;
+	/*
+	 * See if we already have it in the inode itself. IO_idqpp is
+	 * &i_udquot or &i_gdquot. This made the code look weird, but
+	 * made the logic a lot simpler.
+	 */
+	if ((dqp = *IO_idqpp)) {
+		if (dolock)
+			xfs_dqlock(dqp);
+		xfs_dqtrace_entry(dqp, "DQATTACH: found in ip");
+		goto done;
+	}
+
+	/*
+	 * udqhint is the i_udquot field in inode, and is non-NULL only
+	 * when the type arg is XFS_DQ_GROUP. Its purpose is to save a
+	 * lookup by dqid (xfs_qm_dqget) by caching a group dquot inside
+	 * the user dquot.
+	 */
+	ASSERT(!udqhint || type == XFS_DQ_GROUP);
+	if (udqhint && !dolock)
+		xfs_dqlock(udqhint);
+
+	/*
+	 * No need to take dqlock to look at the id.
+	 * The ID can't change until it gets reclaimed, and it won't
+	 * be reclaimed as long as we have a ref from inode and we hold
+	 * the ilock.
+	 */
+	if (udqhint &&
+	    (dqp = udqhint->q_gdquot) &&
+	    (INT_GET(dqp->q_core.d_id, ARCH_CONVERT) == id)) {
+		ASSERT(XFS_DQ_IS_LOCKED(udqhint));
+		xfs_dqlock(dqp);
+		XFS_DQHOLD(dqp);
+		ASSERT(*IO_idqpp == NULL);
+		*IO_idqpp = dqp;
+		if (!dolock) {
+			xfs_dqunlock(dqp);
+			xfs_dqunlock(udqhint);
+		}
+		goto done;
+	}
+	/*
+	 * We can't hold a dquot lock when we call the dqget code.
+	 * We'll deadlock in no time, because of (not conforming to)
+	 * lock ordering - the inodelock comes before any dquot lock,
+	 * and we may drop and reacquire the ilock in xfs_qm_dqget().
+	 */
+	if (udqhint)
+		xfs_dqunlock(udqhint);
+	/*
+	 * Find the dquot from somewhere. This bumps the
+	 * reference count of dquot and returns it locked.
+	 * This can return ENOENT if dquot didn't exist on
+	 * disk and we didn't ask it to allocate;
+	 * ESRCH if quotas got turned off suddenly.
+	 */
+	if ((error = xfs_qm_dqget(ip->i_mount, ip, id, type,
+				 doalloc|XFS_QMOPT_DOWARN, &dqp))) {
+		if (udqhint && dolock)
+			xfs_dqlock(udqhint);
+		goto done;
+	}
+
+	xfs_dqtrace_entry(dqp, "DQATTACH: found by dqget");
+	/*
+	 * dqget may have dropped and re-acquired the ilock, but it guarantees
+	 * that the dquot returned is the one that should go in the inode.
+	 */
+	*IO_idqpp = dqp;
+	ASSERT(dqp);
+	ASSERT(XFS_DQ_IS_LOCKED(dqp));
+	if (! dolock) {
+		xfs_dqunlock(dqp);
+		goto done;
+	}
+	if (! udqhint)
+		goto done;
+
+	ASSERT(udqhint);
+	ASSERT(dolock);
+	ASSERT(XFS_DQ_IS_LOCKED(dqp));
+	if (! xfs_qm_dqlock_nowait(udqhint)) {
+		xfs_dqunlock(dqp);
+		xfs_dqlock(udqhint);
+		xfs_dqlock(dqp);
+	}
+      done:
+#ifdef QUOTADEBUG
+	if (udqhint) {
+		if (dolock)
+			ASSERT(XFS_DQ_IS_LOCKED(udqhint));
+	}
+	if (! error) {
+		if (dolock)
+			ASSERT(XFS_DQ_IS_LOCKED(dqp));
+	}
+#endif
+	return (error);
+}
+
+
+/*
+ * Given a udquot and gdquot, attach a ptr to the group dquot in the
+ * udquot as a hint for future lookups. The idea sounds simple, but the
+ * execution isn't, because the udquot might have a group dquot attached
+ * already and getting rid of that gets us into lock ordering contraints.
+ * The process is complicated more by the fact that the dquots may or may not
+ * be locked on entry.
+ */
+STATIC void
+xfs_qm_dqattach_grouphint(
+	xfs_dquot_t	*udq,
+	xfs_dquot_t	*gdq,
+	uint		locked)
+{
+	xfs_dquot_t	*tmp;
+
+#ifdef QUOTADEBUG
+	if (locked) {
+		ASSERT(XFS_DQ_IS_LOCKED(udq));
+		ASSERT(XFS_DQ_IS_LOCKED(gdq));
+	}
+#endif
+	if (! locked)
+		xfs_dqlock(udq);
+
+	if ((tmp = udq->q_gdquot)) {
+		if (tmp == gdq) {
+			if (! locked)
+				xfs_dqunlock(udq);
+			return;
+		}
+
+		udq->q_gdquot = NULL;
+		/*
+		 * We can't keep any dqlocks when calling dqrele,
+		 * because the freelist lock comes before dqlocks.
+		 */
+		xfs_dqunlock(udq);
+		if (locked)
+			xfs_dqunlock(gdq);
+		/*
+		 * we took a hard reference once upon a time in dqget,
+		 * so give it back when the udquot no longer points at it
+		 * dqput() does the unlocking of the dquot.
+		 */
+		xfs_qm_dqrele(tmp);
+
+		xfs_dqlock(udq);
+		xfs_dqlock(gdq);
+
+	} else {
+		ASSERT(XFS_DQ_IS_LOCKED(udq));
+		if (! locked) {
+			xfs_dqlock(gdq);
+		}
+	}
+
+	ASSERT(XFS_DQ_IS_LOCKED(udq));
+	ASSERT(XFS_DQ_IS_LOCKED(gdq));
+	/*
+	 * Somebody could have attached a gdquot here,
+	 * when we dropped the uqlock. If so, just do nothing.
+	 */
+	if (udq->q_gdquot == NULL) {
+		XFS_DQHOLD(gdq);
+		udq->q_gdquot = gdq;
+	}
+	if (! locked) {
+		xfs_dqunlock(gdq);
+		xfs_dqunlock(udq);
+	}
+}
+
+
+/*
+ * Given a locked inode, attach dquot(s) to it, taking UQUOTAON / GQUOTAON
+ * in to account.
+ * If XFS_QMOPT_DQALLOC, the dquot(s) will be allocated if needed.
+ * If XFS_QMOPT_DQLOCK, the dquot(s) will be returned locked. This option pretty
+ * much made this code a complete mess, but it has been pretty useful.
+ * If XFS_QMOPT_ILOCKED, then inode sent is already locked EXCL.
+ * Inode may get unlocked and relocked in here, and the caller must deal with
+ * the consequences.
+ */
+int
+xfs_qm_dqattach(
+	xfs_inode_t	*ip,
+	uint		flags)
+{
+	xfs_mount_t	*mp = ip->i_mount;
+	uint		nquotas = 0;
+	int		error = 0;
+
+	if ((! XFS_IS_QUOTA_ON(mp)) ||
+	    (! XFS_NOT_DQATTACHED(mp, ip)) ||
+	    (ip->i_ino == mp->m_sb.sb_uquotino) ||
+	    (ip->i_ino == mp->m_sb.sb_gquotino))
+		return (0);
+
+	ASSERT((flags & XFS_QMOPT_ILOCKED) == 0 ||
+	       XFS_ISLOCKED_INODE_EXCL(ip));
+
+	if (! (flags & XFS_QMOPT_ILOCKED))
+		xfs_ilock(ip, XFS_ILOCK_EXCL);
+
+	if (XFS_IS_UQUOTA_ON(mp)) {
+		error = xfs_qm_dqattach_one(ip, ip->i_d.di_uid, XFS_DQ_USER,
+						flags & XFS_QMOPT_DQALLOC,
+						flags & XFS_QMOPT_DQLOCK,
+						NULL, &ip->i_udquot);
+		if (error)
+			goto done;
+		nquotas++;
+	}
+	ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
+	if (XFS_IS_GQUOTA_ON(mp)) {
+		error = xfs_qm_dqattach_one(ip, ip->i_d.di_gid, XFS_DQ_GROUP,
+						flags & XFS_QMOPT_DQALLOC,
+						flags & XFS_QMOPT_DQLOCK,
+						ip->i_udquot, &ip->i_gdquot);
+		/*
+		 * Don't worry about the udquot that we may have
+		 * attached above. It'll get detached, if not already.
+		 */
+		if (error)
+			goto done;
+		nquotas++;
+	}
+
+	/*
+	 * Attach this group quota to the user quota as a hint.
+	 * This WON'T, in general, result in a thrash.
+	 */
+	if (nquotas == 2) {
+		ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
+		ASSERT(ip->i_udquot);
+		ASSERT(ip->i_gdquot);
+
+		/*
+		 * We may or may not have the i_udquot locked at this point,
+		 * but this check is OK since we don't depend on the i_gdquot to
+		 * be accurate 100% all the time. It is just a hint, and this
+		 * will succeed in general.
+		 */
+		if (ip->i_udquot->q_gdquot == ip->i_gdquot)
+			goto done;
+		/*
+		 * Attach i_gdquot to the gdquot hint inside the i_udquot.
+		 */
+		xfs_qm_dqattach_grouphint(ip->i_udquot, ip->i_gdquot,
+					 flags & XFS_QMOPT_DQLOCK);
+	}
+
+      done:
+
+#ifdef QUOTADEBUG
+	if (! error) {
+		if (ip->i_udquot) {
+			if (flags & XFS_QMOPT_DQLOCK)
+				ASSERT(XFS_DQ_IS_LOCKED(ip->i_udquot));
+		}
+		if (ip->i_gdquot) {
+			if (flags & XFS_QMOPT_DQLOCK)
+				ASSERT(XFS_DQ_IS_LOCKED(ip->i_gdquot));
+		}
+		if (XFS_IS_UQUOTA_ON(mp))
+			ASSERT(ip->i_udquot);
+		if (XFS_IS_GQUOTA_ON(mp))
+			ASSERT(ip->i_gdquot);
+	}
+#endif
+
+	if (! (flags & XFS_QMOPT_ILOCKED))
+		xfs_iunlock(ip, XFS_ILOCK_EXCL);
+
+#ifdef QUOTADEBUG
+	else
+		ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
+#endif
+	return (error);
+}
+
+/*
+ * Release dquots (and their references) if any.
+ * The inode should be locked EXCL except when this's called by
+ * xfs_ireclaim.
+ */
+void
+xfs_qm_dqdetach(
+	xfs_inode_t	*ip)
+{
+	if (!(ip->i_udquot || ip->i_gdquot))
+		return;
+
+	ASSERT(ip->i_ino != ip->i_mount->m_sb.sb_uquotino);
+	ASSERT(ip->i_ino != ip->i_mount->m_sb.sb_gquotino);
+	if (ip->i_udquot)
+		xfs_dqtrace_entry_ino(ip->i_udquot, "DQDETTACH", ip);
+	if (ip->i_udquot) {
+		xfs_qm_dqrele(ip->i_udquot);
+		ip->i_udquot = NULL;
+	}
+	if (ip->i_gdquot) {
+		xfs_qm_dqrele(ip->i_gdquot);
+		ip->i_gdquot = NULL;
+	}
+}
+
+/*
+ * This is called by VFS_SYNC and flags arg determines the caller,
+ * and its motives, as done in xfs_sync.
+ *
+ * vfs_sync: SYNC_FSDATA|SYNC_ATTR|SYNC_BDFLUSH 0x31
+ * syscall sync: SYNC_FSDATA|SYNC_ATTR|SYNC_DELWRI 0x25
+ * umountroot : SYNC_WAIT | SYNC_CLOSE | SYNC_ATTR | SYNC_FSDATA
+ */
+
+int
+xfs_qm_sync(
+	xfs_mount_t	*mp,
+	short		flags)
+{
+	int		recl, restarts;
+	xfs_dquot_t	*dqp;
+	uint		flush_flags;
+	boolean_t	nowait;
+	int		error;
+
+	restarts = 0;
+	/*
+	 * We won't block unless we are asked to.
+	 */
+	nowait = (boolean_t)(flags & SYNC_BDFLUSH || (flags & SYNC_WAIT) == 0);
+
+  again:
+	xfs_qm_mplist_lock(mp);
+	/*
+	 * dqpurge_all() also takes the mplist lock and iterate thru all dquots
+	 * in quotaoff. However, if the QUOTA_ACTIVE bits are not cleared
+	 * when we have the mplist lock, we know that dquots will be consistent
+	 * as long as we have it locked.
+	 */
+	if (! XFS_IS_QUOTA_ON(mp)) {
+		xfs_qm_mplist_unlock(mp);
+		return (0);
+	}
+	FOREACH_DQUOT_IN_MP(dqp, mp) {
+		/*
+		 * If this is vfs_sync calling, then skip the dquots that
+		 * don't 'seem' to be dirty. ie. don't acquire dqlock.
+		 * This is very similar to what xfs_sync does with inodes.
+		 */
+		if (flags & SYNC_BDFLUSH) {
+			if (! XFS_DQ_IS_DIRTY(dqp))
+				continue;
+		}
+
+		if (nowait) {
+			/*
+			 * Try to acquire the dquot lock. We are NOT out of
+			 * lock order, but we just don't want to wait for this
+			 * lock, unless somebody wanted us to.
+			 */
+			if (! xfs_qm_dqlock_nowait(dqp))
+				continue;
+		} else {
+			xfs_dqlock(dqp);
+		}
+
+		/*
+		 * Now, find out for sure if this dquot is dirty or not.
+		 */
+		if (! XFS_DQ_IS_DIRTY(dqp)) {
+			xfs_dqunlock(dqp);
+			continue;
+		}
+
+		/* XXX a sentinel would be better */
+		recl = XFS_QI_MPLRECLAIMS(mp);
+		if (! xfs_qm_dqflock_nowait(dqp)) {
+			if (nowait) {
+				xfs_dqunlock(dqp);
+				continue;
+			}
+			/*
+			 * If we can't grab the flush lock then if the caller
+			 * really wanted us to give this our best shot,
+			 * see if we can give a push to the buffer before we wait
+			 * on the flush lock. At this point, we know that
+			 * eventhough the dquot is being flushed,
+			 * it has (new) dirty data.
+			 */
+			xfs_qm_dqflock_pushbuf_wait(dqp);
+		}
+		/*
+		 * Let go of the mplist lock. We don't want to hold it
+		 * across a disk write
+		 */
+		flush_flags = (nowait) ? XFS_QMOPT_DELWRI : XFS_QMOPT_SYNC;
+		xfs_qm_mplist_unlock(mp);
+		xfs_dqtrace_entry(dqp, "XQM_SYNC: DQFLUSH");
+		error = xfs_qm_dqflush(dqp, flush_flags);
+		xfs_dqunlock(dqp);
+		if (error && XFS_FORCED_SHUTDOWN(mp))
+			return(0);	/* Need to prevent umount failure */
+		else if (error)
+			return (error);
+
+		xfs_qm_mplist_lock(mp);
+		if (recl != XFS_QI_MPLRECLAIMS(mp)) {
+			if (++restarts >= XFS_QM_SYNC_MAX_RESTARTS)
+				break;
+
+			xfs_qm_mplist_unlock(mp);
+			goto again;
+		}
+	}
+
+	xfs_qm_mplist_unlock(mp);
+	return (0);
+}
+
+
+/*
+ * This initializes all the quota information that's kept in the
+ * mount structure
+ */
+int
+xfs_qm_init_quotainfo(
+	xfs_mount_t	*mp)
+{
+	xfs_quotainfo_t *qinf;
+	int		error;
+	xfs_dquot_t	*dqp;
+
+	ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+
+	/*
+	 * Tell XQM that we exist as soon as possible.
+	 */
+	if ((error = xfs_qm_hold_quotafs_ref(mp))) {
+		return (error);
+	}
+
+	qinf = mp->m_quotainfo = kmem_zalloc(sizeof(xfs_quotainfo_t), KM_SLEEP);
+
+	/*
+	 * See if quotainodes are setup, and if not, allocate them,
+	 * and change the superblock accordingly.
+	 */
+	if ((error = xfs_qm_init_quotainos(mp))) {
+		kmem_free(qinf, sizeof(xfs_quotainfo_t));
+		mp->m_quotainfo = NULL;
+		return (error);
+	}
+
+	spinlock_init(&qinf->qi_pinlock, "xfs_qinf_pin");
+	xfs_qm_list_init(&qinf->qi_dqlist, "mpdqlist", 0);
+	qinf->qi_dqreclaims = 0;
+
+	/* mutex used to serialize quotaoffs */
+	mutex_init(&qinf->qi_quotaofflock, MUTEX_DEFAULT, "qoff");
+
+	/* Precalc some constants */
+	qinf->qi_dqchunklen = XFS_FSB_TO_BB(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
+	ASSERT(qinf->qi_dqchunklen);
+	qinf->qi_dqperchunk = BBTOB(qinf->qi_dqchunklen);
+	do_div(qinf->qi_dqperchunk, sizeof(xfs_dqblk_t));
+
+	mp->m_qflags |= (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_CHKD);
+
+	/*
+	 * We try to get the limits from the superuser's limits fields.
+	 * This is quite hacky, but it is standard quota practice.
+	 * We look at the USR dquot with id == 0 first, but if user quotas
+	 * are not enabled we goto the GRP dquot with id == 0.
+	 * We don't really care to keep separate default limits for user
+	 * and group quotas, at least not at this point.
+	 */
+	error = xfs_qm_dqget(mp, NULL, (xfs_dqid_t)0,
+			     (XFS_IS_UQUOTA_RUNNING(mp)) ?
+			     XFS_DQ_USER : XFS_DQ_GROUP,
+			     XFS_QMOPT_DQSUSER|XFS_QMOPT_DOWARN,
+			     &dqp);
+	if (! error) {
+		/*
+		 * The warnings and timers set the grace period given to
+		 * a user or group before he or she can not perform any
+		 * more writing. If it is zero, a default is used.
+		 */
+		qinf->qi_btimelimit = INT_GET(dqp->q_core.d_btimer, ARCH_CONVERT) ?
+			INT_GET(dqp->q_core.d_btimer, ARCH_CONVERT) : XFS_QM_BTIMELIMIT;
+		qinf->qi_itimelimit = INT_GET(dqp->q_core.d_itimer, ARCH_CONVERT) ?
+			INT_GET(dqp->q_core.d_itimer, ARCH_CONVERT) : XFS_QM_ITIMELIMIT;
+		qinf->qi_rtbtimelimit = INT_GET(dqp->q_core.d_rtbtimer, ARCH_CONVERT) ?
+			INT_GET(dqp->q_core.d_rtbtimer, ARCH_CONVERT) : XFS_QM_RTBTIMELIMIT;
+		qinf->qi_bwarnlimit = INT_GET(dqp->q_core.d_bwarns, ARCH_CONVERT) ?
+			INT_GET(dqp->q_core.d_bwarns, ARCH_CONVERT) : XFS_QM_BWARNLIMIT;
+		qinf->qi_iwarnlimit = INT_GET(dqp->q_core.d_iwarns, ARCH_CONVERT) ?
+			INT_GET(dqp->q_core.d_iwarns, ARCH_CONVERT) : XFS_QM_IWARNLIMIT;
+
+		/*
+		 * We sent the XFS_QMOPT_DQSUSER flag to dqget because
+		 * we don't want this dquot cached. We haven't done a
+		 * quotacheck yet, and quotacheck doesn't like incore dquots.
+		 */
+		xfs_qm_dqdestroy(dqp);
+	} else {
+		qinf->qi_btimelimit = XFS_QM_BTIMELIMIT;
+		qinf->qi_itimelimit = XFS_QM_ITIMELIMIT;
+		qinf->qi_rtbtimelimit = XFS_QM_RTBTIMELIMIT;
+		qinf->qi_bwarnlimit = XFS_QM_BWARNLIMIT;
+		qinf->qi_iwarnlimit = XFS_QM_IWARNLIMIT;
+	}
+
+	return (0);
+}
+
+
+/*
+ * Gets called when unmounting a filesystem or when all quotas get
+ * turned off.
+ * This purges the quota inodes, destroys locks and frees itself.
+ */
+void
+xfs_qm_destroy_quotainfo(
+	xfs_mount_t	*mp)
+{
+	xfs_quotainfo_t *qi;
+
+	qi = mp->m_quotainfo;
+	ASSERT(qi != NULL);
+	ASSERT(xfs_Gqm != NULL);
+
+	/*
+	 * Release the reference that XQM kept, so that we know
+	 * when the XQM structure should be freed. We cannot assume
+	 * that xfs_Gqm is non-null after this point.
+	 */
+	xfs_qm_rele_quotafs_ref(mp);
+
+	spinlock_destroy(&qi->qi_pinlock);
+	xfs_qm_list_destroy(&qi->qi_dqlist);
+
+	if (qi->qi_uquotaip) {
+		XFS_PURGE_INODE(qi->qi_uquotaip);
+		qi->qi_uquotaip = NULL; /* paranoia */
+	}
+	if (qi->qi_gquotaip) {
+		XFS_PURGE_INODE(qi->qi_gquotaip);
+		qi->qi_gquotaip = NULL;
+	}
+	mutex_destroy(&qi->qi_quotaofflock);
+	kmem_free(qi, sizeof(xfs_quotainfo_t));
+	mp->m_quotainfo = NULL;
+}
+
+
+
+/* ------------------- PRIVATE STATIC FUNCTIONS ----------------------- */
+
+/* ARGSUSED */
+STATIC void
+xfs_qm_list_init(
+	xfs_dqlist_t	*list,
+	char		*str,
+	int		n)
+{
+	mutex_init(&list->qh_lock, MUTEX_DEFAULT, str);
+	list->qh_next = NULL;
+	list->qh_version = 0;
+	list->qh_nelems = 0;
+}
+
+STATIC void
+xfs_qm_list_destroy(
+	xfs_dqlist_t	*list)
+{
+	mutex_destroy(&(list->qh_lock));
+}
+
+
+/*
+ * Stripped down version of dqattach. This doesn't attach, or even look at the
+ * dquots attached to the inode. The rationale is that there won't be any
+ * attached at the time this is called from quotacheck.
+ */
+STATIC int
+xfs_qm_dqget_noattach(
+	xfs_inode_t	*ip,
+	xfs_dquot_t	**O_udqpp,
+	xfs_dquot_t	**O_gdqpp)
+{
+	int		error;
+	xfs_mount_t	*mp;
+	xfs_dquot_t	*udqp, *gdqp;
+
+	ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
+	mp = ip->i_mount;
+	udqp = NULL;
+	gdqp = NULL;
+
+	if (XFS_IS_UQUOTA_ON(mp)) {
+		ASSERT(ip->i_udquot == NULL);
+		/*
+		 * We want the dquot allocated if it doesn't exist.
+		 */
+		if ((error = xfs_qm_dqget(mp, ip, ip->i_d.di_uid, XFS_DQ_USER,
+					 XFS_QMOPT_DQALLOC | XFS_QMOPT_DOWARN,
+					 &udqp))) {
+			/*
+			 * Shouldn't be able to turn off quotas here.
+			 */
+			ASSERT(error != ESRCH);
+			ASSERT(error != ENOENT);
+			return (error);
+		}
+		ASSERT(udqp);
+	}
+
+	if (XFS_IS_GQUOTA_ON(mp)) {
+		ASSERT(ip->i_gdquot == NULL);
+		if (udqp)
+			xfs_dqunlock(udqp);
+		if ((error = xfs_qm_dqget(mp, ip, ip->i_d.di_gid, XFS_DQ_GROUP,
+					 XFS_QMOPT_DQALLOC|XFS_QMOPT_DOWARN,
+					 &gdqp))) {
+			if (udqp)
+				xfs_qm_dqrele(udqp);
+			ASSERT(error != ESRCH);
+			ASSERT(error != ENOENT);
+			return (error);
+		}
+		ASSERT(gdqp);
+
+		/* Reacquire the locks in the right order */
+		if (udqp) {
+			if (! xfs_qm_dqlock_nowait(udqp)) {
+				xfs_dqunlock(gdqp);
+				xfs_dqlock(udqp);
+				xfs_dqlock(gdqp);
+			}
+		}
+	}
+
+	*O_udqpp = udqp;
+	*O_gdqpp = gdqp;
+
+#ifdef QUOTADEBUG
+	if (udqp) ASSERT(XFS_DQ_IS_LOCKED(udqp));
+	if (gdqp) ASSERT(XFS_DQ_IS_LOCKED(gdqp));
+#endif
+	return (0);
+}
+
+/*
+ * Create an inode and return with a reference already taken, but unlocked
+ * This is how we create quota inodes
+ */
+STATIC int
+xfs_qm_qino_alloc(
+	xfs_mount_t	*mp,
+	xfs_inode_t	**ip,
+	__int64_t	sbfields,
+	uint		flags)
+{
+	xfs_trans_t	*tp;
+	int		error;
+	unsigned long s;
+	cred_t		zerocr;
+	int		committed;
+
+	tp = xfs_trans_alloc(mp,XFS_TRANS_QM_QINOCREATE);
+	if ((error = xfs_trans_reserve(tp,
+				      XFS_QM_QINOCREATE_SPACE_RES(mp),
+				      XFS_CREATE_LOG_RES(mp), 0,
+				      XFS_TRANS_PERM_LOG_RES,
+				      XFS_CREATE_LOG_COUNT))) {
+		xfs_trans_cancel(tp, 0);
+		return (error);
+	}
+	memset(&zerocr, 0, sizeof(zerocr));
+
+	if ((error = xfs_dir_ialloc(&tp, mp->m_rootip, S_IFREG, 1, 0,
+				   &zerocr, 0, 1, ip, &committed))) {
+		xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES |
+				 XFS_TRANS_ABORT);
+		return (error);
+	}
+
+	/*
+	 * Keep an extra reference to this quota inode. This inode is
+	 * locked exclusively and joined to the transaction already.
+	 */
+	ASSERT(XFS_ISLOCKED_INODE_EXCL(*ip));
+	VN_HOLD(XFS_ITOV((*ip)));
+
+	/*
+	 * Make the changes in the superblock, and log those too.
+	 * sbfields arg may contain fields other than *QUOTINO;
+	 * VERSIONNUM for example.
+	 */
+	s = XFS_SB_LOCK(mp);
+	if (flags & XFS_QMOPT_SBVERSION) {
+#if defined(DEBUG) && defined(XFS_LOUD_RECOVERY)
+		unsigned oldv = mp->m_sb.sb_versionnum;
+#endif
+		ASSERT(!XFS_SB_VERSION_HASQUOTA(&mp->m_sb));
+		ASSERT((sbfields & (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
+				   XFS_SB_GQUOTINO | XFS_SB_QFLAGS)) ==
+		       (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
+			XFS_SB_GQUOTINO | XFS_SB_QFLAGS));
+
+		XFS_SB_VERSION_ADDQUOTA(&mp->m_sb);
+		mp->m_sb.sb_uquotino = NULLFSINO;
+		mp->m_sb.sb_gquotino = NULLFSINO;
+
+		/* qflags will get updated _after_ quotacheck */
+		mp->m_sb.sb_qflags = 0;
+#if defined(DEBUG) && defined(XFS_LOUD_RECOVERY)
+		cmn_err(CE_NOTE,
+			"Old superblock version %x, converting to %x.",
+			oldv, mp->m_sb.sb_versionnum);
+#endif
+	}
+	if (flags & XFS_QMOPT_UQUOTA)
+		mp->m_sb.sb_uquotino = (*ip)->i_ino;
+	else
+		mp->m_sb.sb_gquotino = (*ip)->i_ino;
+	XFS_SB_UNLOCK(mp, s);
+	xfs_mod_sb(tp, sbfields);
+
+	if ((error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES,
+				     NULL))) {
+		xfs_fs_cmn_err(CE_ALERT, mp, "XFS qino_alloc failed!");
+		return (error);
+	}
+	return (0);
+}
+
+
+STATIC int
+xfs_qm_reset_dqcounts(
+	xfs_mount_t	*mp,
+	xfs_buf_t	*bp,
+	xfs_dqid_t	id,
+	uint		type)
+{
+	xfs_disk_dquot_t	*ddq;
+	int			j;
+
+	xfs_buftrace("RESET DQUOTS", bp);
+	/*
+	 * Reset all counters and timers. They'll be
+	 * started afresh by xfs_qm_quotacheck.
+	 */
+#ifdef DEBUG
+	j = XFS_FSB_TO_B(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);
+	do_div(j, sizeof(xfs_dqblk_t));
+	ASSERT(XFS_QM_DQPERBLK(mp) == j);
+#endif
+	ddq = (xfs_disk_dquot_t *)XFS_BUF_PTR(bp);
+	for (j = 0; j < XFS_QM_DQPERBLK(mp); j++) {
+		/*
+		 * Do a sanity check, and if needed, repair the dqblk. Don't
+		 * output any warnings because it's perfectly possible to
+		 * find unitialized dquot blks. See comment in xfs_qm_dqcheck.
+		 */
+		(void) xfs_qm_dqcheck(ddq, id+j, type, XFS_QMOPT_DQREPAIR,
+				      "xfs_quotacheck");
+		INT_SET(ddq->d_bcount, ARCH_CONVERT, 0ULL);
+		INT_SET(ddq->d_icount, ARCH_CONVERT, 0ULL);
+		INT_SET(ddq->d_rtbcount, ARCH_CONVERT, 0ULL);
+		INT_SET(ddq->d_btimer, ARCH_CONVERT, (time_t)0);
+		INT_SET(ddq->d_itimer, ARCH_CONVERT, (time_t)0);
+		INT_SET(ddq->d_bwarns, ARCH_CONVERT, 0UL);
+		INT_SET(ddq->d_iwarns, ARCH_CONVERT, 0UL);
+		ddq = (xfs_disk_dquot_t *) ((xfs_dqblk_t *)ddq + 1);
+	}
+
+	return (0);
+}
+
+STATIC int
+xfs_qm_dqiter_bufs(
+	xfs_mount_t	*mp,
+	xfs_dqid_t	firstid,
+	xfs_fsblock_t	bno,
+	xfs_filblks_t	blkcnt,
+	uint		flags)
+{
+	xfs_buf_t	*bp;
+	int		error;
+	int		notcommitted;
+	int		incr;
+
+	ASSERT(blkcnt > 0);
+	notcommitted = 0;
+	incr = (blkcnt > XFS_QM_MAX_DQCLUSTER_LOGSZ) ?
+		XFS_QM_MAX_DQCLUSTER_LOGSZ : blkcnt;
+	error = 0;
+
+	/*
+	 * Blkcnt arg can be a very big number, and might even be
+	 * larger than the log itself. So, we have to break it up into
+	 * manageable-sized transactions.
+	 * Note that we don't start a permanent transaction here; we might
+	 * not be able to get a log reservation for the whole thing up front,
+	 * and we don't really care to either, because we just discard
+	 * everything if we were to crash in the middle of this loop.
+	 */
+	while (blkcnt--) {
+		error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
+			      XFS_FSB_TO_DADDR(mp, bno),
+			      (int)XFS_QI_DQCHUNKLEN(mp), 0, &bp);
+		if (error)
+			break;
+
+		(void) xfs_qm_reset_dqcounts(mp, bp, firstid,
+					     flags & XFS_QMOPT_UQUOTA ?
+					     XFS_DQ_USER : XFS_DQ_GROUP);
+		xfs_bdwrite(mp, bp);
+		/*
+		 * goto the next block.
+		 */
+		bno++;
+		firstid += XFS_QM_DQPERBLK(mp);
+	}
+	return (error);
+}
+
+/*
+ * Iterate over all allocated USR/GRP dquots in the system, calling a
+ * caller supplied function for every chunk of dquots that we find.
+ */
+STATIC int
+xfs_qm_dqiterate(
+	xfs_mount_t	*mp,
+	xfs_inode_t	*qip,
+	uint		flags)
+{
+	xfs_bmbt_irec_t		*map;
+	int			i, nmaps;	/* number of map entries */
+	int			error;		/* return value */
+	xfs_fileoff_t		lblkno;
+	xfs_filblks_t		maxlblkcnt;
+	xfs_dqid_t		firstid;
+	xfs_fsblock_t		rablkno;
+	xfs_filblks_t		rablkcnt;
+
+	error = 0;
+	/*
+	 * This looks racey, but we can't keep an inode lock across a
+	 * trans_reserve. But, this gets called during quotacheck, and that
+	 * happens only at mount time which is single threaded.
+	 */
+	if (qip->i_d.di_nblocks == 0)
+		return (0);
+
+	map = kmem_alloc(XFS_DQITER_MAP_SIZE * sizeof(*map), KM_SLEEP);
+
+	lblkno = 0;
+	maxlblkcnt = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
+	do {
+		nmaps = XFS_DQITER_MAP_SIZE;
+		/*
+		 * We aren't changing the inode itself. Just changing
+		 * some of its data. No new blocks are added here, and
+		 * the inode is never added to the transaction.
+		 */
+		xfs_ilock(qip, XFS_ILOCK_SHARED);
+		error = xfs_bmapi(NULL, qip, lblkno,
+				  maxlblkcnt - lblkno,
+				  XFS_BMAPI_METADATA,
+				  NULL,
+				  0, map, &nmaps, NULL);
+		xfs_iunlock(qip, XFS_ILOCK_SHARED);
+		if (error)
+			break;
+
+		ASSERT(nmaps <= XFS_DQITER_MAP_SIZE);
+		for (i = 0; i < nmaps; i++) {
+			ASSERT(map[i].br_startblock != DELAYSTARTBLOCK);
+			ASSERT(map[i].br_blockcount);
+
+
+			lblkno += map[i].br_blockcount;
+
+			if (map[i].br_startblock == HOLESTARTBLOCK)
+				continue;
+
+			firstid = (xfs_dqid_t) map[i].br_startoff *
+				XFS_QM_DQPERBLK(mp);
+			/*
+			 * Do a read-ahead on the next extent.
+			 */
+			if ((i+1 < nmaps) &&
+			    (map[i+1].br_startblock != HOLESTARTBLOCK)) {
+				rablkcnt =  map[i+1].br_blockcount;
+				rablkno = map[i+1].br_startblock;
+				while (rablkcnt--) {
+					xfs_baread(mp->m_ddev_targp,
+					       XFS_FSB_TO_DADDR(mp, rablkno),
+					       (int)XFS_QI_DQCHUNKLEN(mp));
+					rablkno++;
+				}
+			}
+			/*
+			 * Iterate thru all the blks in the extent and
+			 * reset the counters of all the dquots inside them.
+			 */
+			if ((error = xfs_qm_dqiter_bufs(mp,
+						       firstid,
+						       map[i].br_startblock,
+						       map[i].br_blockcount,
+						       flags))) {
+				break;
+			}
+		}
+
+		if (error)
+			break;
+	} while (nmaps > 0);
+
+	kmem_free(map, XFS_DQITER_MAP_SIZE * sizeof(*map));
+
+	return (error);
+}
+
+/*
+ * Called by dqusage_adjust in doing a quotacheck.
+ * Given the inode, and a dquot (either USR or GRP, doesn't matter),
+ * this updates its incore copy as well as the buffer copy. This is
+ * so that once the quotacheck is done, we can just log all the buffers,
+ * as opposed to logging numerous updates to individual dquots.
+ */
+STATIC void
+xfs_qm_quotacheck_dqadjust(
+	xfs_dquot_t		*dqp,
+	xfs_qcnt_t		nblks,
+	xfs_qcnt_t		rtblks)
+{
+	ASSERT(XFS_DQ_IS_LOCKED(dqp));
+	xfs_dqtrace_entry(dqp, "QCHECK DQADJUST");
+	/*
+	 * Adjust the inode count and the block count to reflect this inode's
+	 * resource usage.
+	 */
+	INT_MOD(dqp->q_core.d_icount, ARCH_CONVERT, +1);
+	dqp->q_res_icount++;
+	if (nblks) {
+		INT_MOD(dqp->q_core.d_bcount, ARCH_CONVERT, nblks);
+		dqp->q_res_bcount += nblks;
+	}
+	if (rtblks) {
+		INT_MOD(dqp->q_core.d_rtbcount, ARCH_CONVERT, rtblks);
+		dqp->q_res_rtbcount += rtblks;
+	}
+
+	/*
+	 * Adjust the timers since we just changed usages
+	 */
+	if (! XFS_IS_SUSER_DQUOT(dqp))
+		xfs_qm_adjust_dqtimers(dqp->q_mount, &dqp->q_core);
+
+	dqp->dq_flags |= XFS_DQ_DIRTY;
+}
+
+STATIC int
+xfs_qm_get_rtblks(
+	xfs_inode_t	*ip,
+	xfs_qcnt_t	*O_rtblks)
+{
+	xfs_filblks_t	rtblks;			/* total rt blks */
+	xfs_ifork_t	*ifp;			/* inode fork pointer */
+	xfs_extnum_t	nextents;		/* number of extent entries */
+	xfs_bmbt_rec_t	*base;			/* base of extent array */
+	xfs_bmbt_rec_t	*ep;			/* pointer to an extent entry */
+	int		error;
+
+	ASSERT(XFS_IS_REALTIME_INODE(ip));
+	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		if ((error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK)))
+			return (error);
+	}
+	rtblks = 0;
+	nextents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
+	base = &ifp->if_u1.if_extents[0];
+	for (ep = base; ep < &base[nextents]; ep++)
+		rtblks += xfs_bmbt_get_blockcount(ep);
+	*O_rtblks = (xfs_qcnt_t)rtblks;
+	return (0);
+}
+
+/*
+ * callback routine supplied to bulkstat(). Given an inumber, find its
+ * dquots and update them to account for resources taken by that inode.
+ */
+/* ARGSUSED */
+STATIC int
+xfs_qm_dqusage_adjust(
+	xfs_mount_t	*mp,		/* mount point for filesystem */
+	xfs_trans_t	*tp,		/* transaction pointer - NULL */
+	xfs_ino_t	ino,		/* inode number to get data for */
+	void		*buffer,	/* not used */
+	int		ubsize,		/* not used */
+	void		*private_data,	/* not used */
+	xfs_daddr_t	bno,		/* starting block of inode cluster */
+	int		*ubused,	/* not used */
+	void		*dip,		/* on-disk inode pointer (not used) */
+	int		*res)		/* result code value */
+{
+	xfs_inode_t	*ip;
+	xfs_dquot_t	*udqp, *gdqp;
+	xfs_qcnt_t	nblks, rtblks;
+	int		error;
+
+	ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+
+	/*
+	 * rootino must have its resources accounted for, not so with the quota
+	 * inodes.
+	 */
+	if (ino == mp->m_sb.sb_uquotino || ino == mp->m_sb.sb_gquotino) {
+		*res = BULKSTAT_RV_NOTHING;
+		return XFS_ERROR(EINVAL);
+	}
+
+	/*
+	 * We don't _need_ to take the ilock EXCL. However, the xfs_qm_dqget
+	 * interface expects the inode to be exclusively locked because that's
+	 * the case in all other instances. It's OK that we do this because
+	 * quotacheck is done only at mount time.
+	 */
+	if ((error = xfs_iget(mp, tp, ino, XFS_ILOCK_EXCL, &ip, bno))) {
+		*res = BULKSTAT_RV_NOTHING;
+		return (error);
+	}
+
+	if (ip->i_d.di_mode == 0) {
+		xfs_iput_new(ip, XFS_ILOCK_EXCL);
+		*res = BULKSTAT_RV_NOTHING;
+		return XFS_ERROR(ENOENT);
+	}
+
+	/*
+	 * Obtain the locked dquots. In case of an error (eg. allocation
+	 * fails for ENOSPC), we return the negative of the error number
+	 * to bulkstat, so that it can get propagated to quotacheck() and
+	 * making us disable quotas for the file system.
+	 */
+	if ((error = xfs_qm_dqget_noattach(ip, &udqp, &gdqp))) {
+		xfs_iput(ip, XFS_ILOCK_EXCL);
+		*res = BULKSTAT_RV_GIVEUP;
+		return (error);
+	}
+
+	rtblks = 0;
+	if (! XFS_IS_REALTIME_INODE(ip)) {
+		nblks = (xfs_qcnt_t)ip->i_d.di_nblocks;
+	} else {
+		/*
+		 * Walk thru the extent list and count the realtime blocks.
+		 */
+		if ((error = xfs_qm_get_rtblks(ip, &rtblks))) {
+			xfs_iput(ip, XFS_ILOCK_EXCL);
+			if (udqp)
+				xfs_qm_dqput(udqp);
+			if (gdqp)
+				xfs_qm_dqput(gdqp);
+			*res = BULKSTAT_RV_GIVEUP;
+			return (error);
+		}
+		nblks = (xfs_qcnt_t)ip->i_d.di_nblocks - rtblks;
+	}
+	ASSERT(ip->i_delayed_blks == 0);
+
+	/*
+	 * We can't release the inode while holding its dquot locks.
+	 * The inode can go into inactive and might try to acquire the dquotlocks.
+	 * So, just unlock here and do a vn_rele at the end.
+	 */
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+
+	/*
+	 * Add the (disk blocks and inode) resources occupied by this
+	 * inode to its dquots. We do this adjustment in the incore dquot,
+	 * and also copy the changes to its buffer.
+	 * We don't care about putting these changes in a transaction
+	 * envelope because if we crash in the middle of a 'quotacheck'
+	 * we have to start from the beginning anyway.
+	 * Once we're done, we'll log all the dquot bufs.
+	 *
+	 * The *QUOTA_ON checks below may look pretty racey, but quotachecks
+	 * and quotaoffs don't race. (Quotachecks happen at mount time only).
+	 */
+	if (XFS_IS_UQUOTA_ON(mp)) {
+		ASSERT(udqp);
+		xfs_qm_quotacheck_dqadjust(udqp, nblks, rtblks);
+		xfs_qm_dqput(udqp);
+	}
+	if (XFS_IS_GQUOTA_ON(mp)) {
+		ASSERT(gdqp);
+		xfs_qm_quotacheck_dqadjust(gdqp, nblks, rtblks);
+		xfs_qm_dqput(gdqp);
+	}
+	/*
+	 * Now release the inode. This will send it to 'inactive', and
+	 * possibly even free blocks.
+	 */
+	VN_RELE(XFS_ITOV(ip));
+
+	/*
+	 * Goto next inode.
+	 */
+	*res = BULKSTAT_RV_DIDONE;
+	return (0);
+}
+
+/*
+ * Walk thru all the filesystem inodes and construct a consistent view
+ * of the disk quota world.
+ */
+STATIC int
+xfs_qm_quotacheck(
+	xfs_mount_t	*mp)
+{
+	int		done, count, error;
+	xfs_ino_t	lastino;
+	size_t		structsz;
+	xfs_inode_t	*uip, *gip;
+	uint		flags;
+
+	count = INT_MAX;
+	structsz = 1;
+	lastino = 0;
+	flags = 0;
+
+	ASSERT(XFS_QI_UQIP(mp) || XFS_QI_GQIP(mp));
+	ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+
+	/*
+	 * There should be no cached dquots. The (simplistic) quotacheck
+	 * algorithm doesn't like that.
+	 */
+	ASSERT(XFS_QI_MPLNDQUOTS(mp) == 0);
+
+	cmn_err(CE_NOTE, "XFS quotacheck %s: Please wait.", mp->m_fsname);
+
+	/*
+	 * First we go thru all the dquots on disk, USR and GRP, and reset
+	 * their counters to zero. We need a clean slate.
+	 * We don't log our changes till later.
+	 */
+	if ((uip = XFS_QI_UQIP(mp))) {
+		if ((error = xfs_qm_dqiterate(mp, uip, XFS_QMOPT_UQUOTA)))
+			goto error_return;
+		flags |= XFS_UQUOTA_CHKD;
+	}
+
+	if ((gip = XFS_QI_GQIP(mp))) {
+		if ((error = xfs_qm_dqiterate(mp, gip, XFS_QMOPT_GQUOTA)))
+			goto error_return;
+		flags |= XFS_GQUOTA_CHKD;
+	}
+
+	do {
+		/*
+		 * Iterate thru all the inodes in the file system,
+		 * adjusting the corresponding dquot counters in core.
+		 */
+		if ((error = xfs_bulkstat(mp, NULL, &lastino, &count,
+				     xfs_qm_dqusage_adjust, NULL,
+				     structsz, NULL,
+				     BULKSTAT_FG_IGET|BULKSTAT_FG_VFSLOCKED,
+				     &done)))
+			break;
+
+	} while (! done);
+
+	/*
+	 * We can get this error if we couldn't do a dquot allocation inside
+	 * xfs_qm_dqusage_adjust (via bulkstat). We don't care about the
+	 * dirty dquots that might be cached, we just want to get rid of them
+	 * and turn quotaoff. The dquots won't be attached to any of the inodes
+	 * at this point (because we intentionally didn't in dqget_noattach).
+	 */
+	if (error) {
+		xfs_qm_dqpurge_all(mp,
+				   XFS_QMOPT_UQUOTA|XFS_QMOPT_GQUOTA|
+				   XFS_QMOPT_QUOTAOFF);
+		goto error_return;
+	}
+	/*
+	 * We've made all the changes that we need to make incore.
+	 * Now flush_them down to disk buffers.
+	 */
+	xfs_qm_dqflush_all(mp, XFS_QMOPT_DELWRI);
+
+	/*
+	 * We didn't log anything, because if we crashed, we'll have to
+	 * start the quotacheck from scratch anyway. However, we must make
+	 * sure that our dquot changes are secure before we put the
+	 * quotacheck'd stamp on the superblock. So, here we do a synchronous
+	 * flush.
+	 */
+	XFS_bflush(mp->m_ddev_targp);
+
+	/*
+	 * If one type of quotas is off, then it will lose its
+	 * quotachecked status, since we won't be doing accounting for
+	 * that type anymore.
+	 */
+	mp->m_qflags &= ~(XFS_GQUOTA_CHKD | XFS_UQUOTA_CHKD);
+	mp->m_qflags |= flags;
+
+	XQM_LIST_PRINT(&(XFS_QI_MPL_LIST(mp)), MPL_NEXT, "++++ Mp list +++");
+
+ error_return:
+	cmn_err(CE_NOTE, "XFS quotacheck %s: Done.", mp->m_fsname);
+	return (error);
+}
+
+/*
+ * This is called after the superblock has been read in and we're ready to
+ * iget the quota inodes.
+ */
+STATIC int
+xfs_qm_init_quotainos(
+	xfs_mount_t	*mp)
+{
+	xfs_inode_t	*uip, *gip;
+	int		error;
+	__int64_t	sbflags;
+	uint		flags;
+
+	ASSERT(mp->m_quotainfo);
+	uip = gip = NULL;
+	sbflags = 0;
+	flags = 0;
+
+	/*
+	 * Get the uquota and gquota inodes
+	 */
+	if (XFS_SB_VERSION_HASQUOTA(&mp->m_sb)) {
+		if (XFS_IS_UQUOTA_ON(mp) &&
+		    mp->m_sb.sb_uquotino != NULLFSINO) {
+			ASSERT(mp->m_sb.sb_uquotino > 0);
+			if ((error = xfs_iget(mp, NULL, mp->m_sb.sb_uquotino,
+					     0, &uip, 0)))
+				return XFS_ERROR(error);
+		}
+		if (XFS_IS_GQUOTA_ON(mp) &&
+		    mp->m_sb.sb_gquotino != NULLFSINO) {
+			ASSERT(mp->m_sb.sb_gquotino > 0);
+			if ((error = xfs_iget(mp, NULL, mp->m_sb.sb_gquotino,
+					     0, &gip, 0))) {
+				if (uip)
+					VN_RELE(XFS_ITOV(uip));
+				return XFS_ERROR(error);
+			}
+		}
+	} else {
+		flags |= XFS_QMOPT_SBVERSION;
+		sbflags |= (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
+			    XFS_SB_GQUOTINO | XFS_SB_QFLAGS);
+	}
+
+	/*
+	 * Create the two inodes, if they don't exist already. The changes
+	 * made above will get added to a transaction and logged in one of
+	 * the qino_alloc calls below.  If the device is readonly,
+	 * temporarily switch to read-write to do this.
+	 */
+	if (XFS_IS_UQUOTA_ON(mp) && uip == NULL) {
+		if ((error = xfs_qm_qino_alloc(mp, &uip,
+					      sbflags | XFS_SB_UQUOTINO,
+					      flags | XFS_QMOPT_UQUOTA)))
+			return XFS_ERROR(error);
+
+		flags &= ~XFS_QMOPT_SBVERSION;
+	}
+	if (XFS_IS_GQUOTA_ON(mp) && gip == NULL) {
+		if ((error = xfs_qm_qino_alloc(mp, &gip,
+					      sbflags | XFS_SB_GQUOTINO,
+					      flags | XFS_QMOPT_GQUOTA))) {
+			if (uip)
+				VN_RELE(XFS_ITOV(uip));
+
+			return XFS_ERROR(error);
+		}
+	}
+
+	XFS_QI_UQIP(mp) = uip;
+	XFS_QI_GQIP(mp) = gip;
+
+	return (0);
+}
+
+
+/*
+ * Traverse the freelist of dquots and attempt to reclaim a maximum of
+ * 'howmany' dquots. This operation races with dqlookup(), and attempts to
+ * favor the lookup function ...
+ * XXXsup merge this with qm_reclaim_one().
+ */
+STATIC int
+xfs_qm_shake_freelist(
+	int howmany)
+{
+	int		nreclaimed;
+	xfs_dqhash_t	*hash;
+	xfs_dquot_t	*dqp, *nextdqp;
+	int		restarts;
+	int		nflushes;
+
+	if (howmany <= 0)
+		return (0);
+
+	nreclaimed = 0;
+	restarts = 0;
+	nflushes = 0;
+
+#ifdef QUOTADEBUG
+	cmn_err(CE_DEBUG, "Shake free 0x%x", howmany);
+#endif
+	/* lock order is : hashchainlock, freelistlock, mplistlock */
+ tryagain:
+	xfs_qm_freelist_lock(xfs_Gqm);
+
+	for (dqp = xfs_Gqm->qm_dqfreelist.qh_next;
+	     ((dqp != (xfs_dquot_t *) &xfs_Gqm->qm_dqfreelist) &&
+	      nreclaimed < howmany); ) {
+		xfs_dqlock(dqp);
+
+		/*
+		 * We are racing with dqlookup here. Naturally we don't
+		 * want to reclaim a dquot that lookup wants.
+		 */
+		if (dqp->dq_flags & XFS_DQ_WANT) {
+			xfs_dqunlock(dqp);
+			xfs_qm_freelist_unlock(xfs_Gqm);
+			if (++restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
+				return (nreclaimed);
+			XQM_STATS_INC(xqmstats.xs_qm_dqwants);
+			goto tryagain;
+		}
+
+		/*
+		 * If the dquot is inactive, we are assured that it is
+		 * not on the mplist or the hashlist, and that makes our
+		 * life easier.
+		 */
+		if (dqp->dq_flags & XFS_DQ_INACTIVE) {
+			ASSERT(dqp->q_mount == NULL);
+			ASSERT(! XFS_DQ_IS_DIRTY(dqp));
+			ASSERT(dqp->HL_PREVP == NULL);
+			ASSERT(dqp->MPL_PREVP == NULL);
+			XQM_STATS_INC(xqmstats.xs_qm_dqinact_reclaims);
+			nextdqp = dqp->dq_flnext;
+			goto off_freelist;
+		}
+
+		ASSERT(dqp->MPL_PREVP);
+		/*
+		 * Try to grab the flush lock. If this dquot is in the process of
+		 * getting flushed to disk, we don't want to reclaim it.
+		 */
+		if (! xfs_qm_dqflock_nowait(dqp)) {
+			xfs_dqunlock(dqp);
+			dqp = dqp->dq_flnext;
+			continue;
+		}
+
+		/*
+		 * We have the flush lock so we know that this is not in the
+		 * process of being flushed. So, if this is dirty, flush it
+		 * DELWRI so that we don't get a freelist infested with
+		 * dirty dquots.
+		 */
+		if (XFS_DQ_IS_DIRTY(dqp)) {
+			xfs_dqtrace_entry(dqp, "DQSHAKE: DQDIRTY");
+			/*
+			 * We flush it delayed write, so don't bother
+			 * releasing the mplock.
+			 */
+			(void) xfs_qm_dqflush(dqp, XFS_QMOPT_DELWRI);
+			xfs_dqunlock(dqp); /* dqflush unlocks dqflock */
+			dqp = dqp->dq_flnext;
+			continue;
+		}
+		/*
+		 * We're trying to get the hashlock out of order. This races
+		 * with dqlookup; so, we giveup and goto the next dquot if
+		 * we couldn't get the hashlock. This way, we won't starve
+		 * a dqlookup process that holds the hashlock that is
+		 * waiting for the freelist lock.
+		 */
+		if (! xfs_qm_dqhashlock_nowait(dqp)) {
+			xfs_dqfunlock(dqp);
+			xfs_dqunlock(dqp);
+			dqp = dqp->dq_flnext;
+			continue;
+		}
+		/*
+		 * This races with dquot allocation code as well as dqflush_all
+		 * and reclaim code. So, if we failed to grab the mplist lock,
+		 * giveup everything and start over.
+		 */
+		hash = dqp->q_hash;
+		ASSERT(hash);
+		if (! xfs_qm_mplist_nowait(dqp->q_mount)) {
+			/* XXX put a sentinel so that we can come back here */
+			xfs_dqfunlock(dqp);
+			xfs_dqunlock(dqp);
+			XFS_DQ_HASH_UNLOCK(hash);
+			xfs_qm_freelist_unlock(xfs_Gqm);
+			if (++restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
+				return (nreclaimed);
+			goto tryagain;
+		}
+		xfs_dqtrace_entry(dqp, "DQSHAKE: UNLINKING");
+#ifdef QUOTADEBUG
+		cmn_err(CE_DEBUG, "Shake 0x%p, ID 0x%x\n",
+			dqp, INT_GET(dqp->q_core.d_id, ARCH_CONVERT));
+#endif
+		ASSERT(dqp->q_nrefs == 0);
+		nextdqp = dqp->dq_flnext;
+		XQM_MPLIST_REMOVE(&(XFS_QI_MPL_LIST(dqp->q_mount)), dqp);
+		XQM_HASHLIST_REMOVE(hash, dqp);
+		xfs_dqfunlock(dqp);
+		xfs_qm_mplist_unlock(dqp->q_mount);
+		XFS_DQ_HASH_UNLOCK(hash);
+
+ off_freelist:
+		XQM_FREELIST_REMOVE(dqp);
+		xfs_dqunlock(dqp);
+		nreclaimed++;
+		XQM_STATS_INC(xqmstats.xs_qm_dqshake_reclaims);
+		xfs_qm_dqdestroy(dqp);
+		dqp = nextdqp;
+	}
+	xfs_qm_freelist_unlock(xfs_Gqm);
+	return (nreclaimed);
+}
+
+
+/*
+ * The kmem_shake interface is invoked when memory is running low.
+ */
+/* ARGSUSED */
+STATIC int
+xfs_qm_shake(int nr_to_scan, unsigned int gfp_mask)
+{
+	int	ndqused, nfree, n;
+
+	if (!kmem_shake_allow(gfp_mask))
+		return (0);
+	if (!xfs_Gqm)
+		return (0);
+
+	nfree = xfs_Gqm->qm_dqfreelist.qh_nelems; /* free dquots */
+	/* incore dquots in all f/s's */
+	ndqused = atomic_read(&xfs_Gqm->qm_totaldquots) - nfree;
+
+	ASSERT(ndqused >= 0);
+
+	if (nfree <= ndqused && nfree < ndquot)
+		return (0);
+
+	ndqused *= xfs_Gqm->qm_dqfree_ratio;	/* target # of free dquots */
+	n = nfree - ndqused - ndquot;		/* # over target */
+
+	return xfs_qm_shake_freelist(MAX(nfree, n));
+}
+
+
+/*
+ * Just pop the least recently used dquot off the freelist and
+ * recycle it. The returned dquot is locked.
+ */
+STATIC xfs_dquot_t *
+xfs_qm_dqreclaim_one(void)
+{
+	xfs_dquot_t	*dqpout;
+	xfs_dquot_t	*dqp;
+	int		restarts;
+	int		nflushes;
+
+	restarts = 0;
+	dqpout = NULL;
+	nflushes = 0;
+
+	/* lockorder: hashchainlock, freelistlock, mplistlock, dqlock, dqflock */
+ startagain:
+	xfs_qm_freelist_lock(xfs_Gqm);
+
+	FOREACH_DQUOT_IN_FREELIST(dqp, &(xfs_Gqm->qm_dqfreelist)) {
+		xfs_dqlock(dqp);
+
+		/*
+		 * We are racing with dqlookup here. Naturally we don't
+		 * want to reclaim a dquot that lookup wants. We release the
+		 * freelist lock and start over, so that lookup will grab
+		 * both the dquot and the freelistlock.
+		 */
+		if (dqp->dq_flags & XFS_DQ_WANT) {
+			ASSERT(! (dqp->dq_flags & XFS_DQ_INACTIVE));
+			xfs_dqtrace_entry(dqp, "DQRECLAIM: DQWANT");
+			xfs_dqunlock(dqp);
+			xfs_qm_freelist_unlock(xfs_Gqm);
+			if (++restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
+				return (NULL);
+			XQM_STATS_INC(xqmstats.xs_qm_dqwants);
+			goto startagain;
+		}
+
+		/*
+		 * If the dquot is inactive, we are assured that it is
+		 * not on the mplist or the hashlist, and that makes our
+		 * life easier.
+		 */
+		if (dqp->dq_flags & XFS_DQ_INACTIVE) {
+			ASSERT(dqp->q_mount == NULL);
+			ASSERT(! XFS_DQ_IS_DIRTY(dqp));
+			ASSERT(dqp->HL_PREVP == NULL);
+			ASSERT(dqp->MPL_PREVP == NULL);
+			XQM_FREELIST_REMOVE(dqp);
+			xfs_dqunlock(dqp);
+			dqpout = dqp;
+			XQM_STATS_INC(xqmstats.xs_qm_dqinact_reclaims);
+			break;
+		}
+
+		ASSERT(dqp->q_hash);
+		ASSERT(dqp->MPL_PREVP);
+
+		/*
+		 * Try to grab the flush lock. If this dquot is in the process of
+		 * getting flushed to disk, we don't want to reclaim it.
+		 */
+		if (! xfs_qm_dqflock_nowait(dqp)) {
+			xfs_dqunlock(dqp);
+			continue;
+		}
+
+		/*
+		 * We have the flush lock so we know that this is not in the
+		 * process of being flushed. So, if this is dirty, flush it
+		 * DELWRI so that we don't get a freelist infested with
+		 * dirty dquots.
+		 */
+		if (XFS_DQ_IS_DIRTY(dqp)) {
+			xfs_dqtrace_entry(dqp, "DQRECLAIM: DQDIRTY");
+			/*
+			 * We flush it delayed write, so don't bother
+			 * releasing the freelist lock.
+			 */
+			(void) xfs_qm_dqflush(dqp, XFS_QMOPT_DELWRI);
+			xfs_dqunlock(dqp); /* dqflush unlocks dqflock */
+			continue;
+		}
+
+		if (! xfs_qm_mplist_nowait(dqp->q_mount)) {
+			xfs_dqfunlock(dqp);
+			xfs_dqunlock(dqp);
+			continue;
+		}
+
+		if (! xfs_qm_dqhashlock_nowait(dqp))
+			goto mplistunlock;
+
+		ASSERT(dqp->q_nrefs == 0);
+		xfs_dqtrace_entry(dqp, "DQRECLAIM: UNLINKING");
+		XQM_MPLIST_REMOVE(&(XFS_QI_MPL_LIST(dqp->q_mount)), dqp);
+		XQM_HASHLIST_REMOVE(dqp->q_hash, dqp);
+		XQM_FREELIST_REMOVE(dqp);
+		dqpout = dqp;
+		XFS_DQ_HASH_UNLOCK(dqp->q_hash);
+ mplistunlock:
+		xfs_qm_mplist_unlock(dqp->q_mount);
+		xfs_dqfunlock(dqp);
+		xfs_dqunlock(dqp);
+		if (dqpout)
+			break;
+	}
+
+	xfs_qm_freelist_unlock(xfs_Gqm);
+	return (dqpout);
+}
+
+
+/*------------------------------------------------------------------*/
+
+/*
+ * Return a new incore dquot. Depending on the number of
+ * dquots in the system, we either allocate a new one on the kernel heap,
+ * or reclaim a free one.
+ * Return value is B_TRUE if we allocated a new dquot, B_FALSE if we managed
+ * to reclaim an existing one from the freelist.
+ */
+boolean_t
+xfs_qm_dqalloc_incore(
+	xfs_dquot_t **O_dqpp)
+{
+	xfs_dquot_t	*dqp;
+
+	/*
+	 * Check against high water mark to see if we want to pop
+	 * a nincompoop dquot off the freelist.
+	 */
+	if (atomic_read(&xfs_Gqm->qm_totaldquots) >= ndquot) {
+		/*
+		 * Try to recycle a dquot from the freelist.
+		 */
+		if ((dqp = xfs_qm_dqreclaim_one())) {
+			XQM_STATS_INC(xqmstats.xs_qm_dqreclaims);
+			/*
+			 * Just zero the core here. The rest will get
+			 * reinitialized by caller. XXX we shouldn't even
+			 * do this zero ...
+			 */
+			memset(&dqp->q_core, 0, sizeof(dqp->q_core));
+			*O_dqpp = dqp;
+			return (B_FALSE);
+		}
+		XQM_STATS_INC(xqmstats.xs_qm_dqreclaim_misses);
+	}
+
+	/*
+	 * Allocate a brand new dquot on the kernel heap and return it
+	 * to the caller to initialize.
+	 */
+	ASSERT(xfs_Gqm->qm_dqzone != NULL);
+	*O_dqpp = kmem_zone_zalloc(xfs_Gqm->qm_dqzone, KM_SLEEP);
+	atomic_inc(&xfs_Gqm->qm_totaldquots);
+
+	return (B_TRUE);
+}
+
+
+/*
+ * Start a transaction and write the incore superblock changes to
+ * disk. flags parameter indicates which fields have changed.
+ */
+int
+xfs_qm_write_sb_changes(
+	xfs_mount_t	*mp,
+	__int64_t	flags)
+{
+	xfs_trans_t	*tp;
+	int		error;
+
+#ifdef QUOTADEBUG
+	cmn_err(CE_NOTE, "Writing superblock quota changes :%s", mp->m_fsname);
+#endif
+	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
+	if ((error = xfs_trans_reserve(tp, 0,
+				      mp->m_sb.sb_sectsize + 128, 0,
+				      0,
+				      XFS_DEFAULT_LOG_COUNT))) {
+		xfs_trans_cancel(tp, 0);
+		return (error);
+	}
+
+	xfs_mod_sb(tp, flags);
+	(void) xfs_trans_commit(tp, 0, NULL);
+
+	return (0);
+}
+
+
+/* --------------- utility functions for vnodeops ---------------- */
+
+
+/*
+ * Given an inode, a uid and gid (from cred_t) make sure that we have
+ * allocated relevant dquot(s) on disk, and that we won't exceed inode
+ * quotas by creating this file.
+ * This also attaches dquot(s) to the given inode after locking it,
+ * and returns the dquots corresponding to the uid and/or gid.
+ *
+ * in	: inode (unlocked)
+ * out	: udquot, gdquot with references taken and unlocked
+ */
+int
+xfs_qm_vop_dqalloc(
+	xfs_mount_t	*mp,
+	xfs_inode_t	*ip,
+	uid_t		uid,
+	gid_t		gid,
+	uint		flags,
+	xfs_dquot_t	**O_udqpp,
+	xfs_dquot_t	**O_gdqpp)
+{
+	int		error;
+	xfs_dquot_t	*uq, *gq;
+	uint		lockflags;
+
+	if (!XFS_IS_QUOTA_ON(mp))
+		return 0;
+
+	lockflags = XFS_ILOCK_EXCL;
+	xfs_ilock(ip, lockflags);
+
+	if ((flags & XFS_QMOPT_INHERIT) &&
+	    XFS_INHERIT_GID(ip, XFS_MTOVFS(mp)))
+		gid = ip->i_d.di_gid;
+
+	/*
+	 * Attach the dquot(s) to this inode, doing a dquot allocation
+	 * if necessary. The dquot(s) will not be locked.
+	 */
+	if (XFS_NOT_DQATTACHED(mp, ip)) {
+		if ((error = xfs_qm_dqattach(ip, XFS_QMOPT_DQALLOC |
+					    XFS_QMOPT_ILOCKED))) {
+			xfs_iunlock(ip, lockflags);
+			return (error);
+		}
+	}
+
+	uq = gq = NULL;
+	if ((flags & XFS_QMOPT_UQUOTA) &&
+	    XFS_IS_UQUOTA_ON(mp)) {
+		if (ip->i_d.di_uid != uid) {
+			/*
+			 * What we need is the dquot that has this uid, and
+			 * if we send the inode to dqget, the uid of the inode
+			 * takes priority over what's sent in the uid argument.
+			 * We must unlock inode here before calling dqget if
+			 * we're not sending the inode, because otherwise
+			 * we'll deadlock by doing trans_reserve while
+			 * holding ilock.
+			 */
+			xfs_iunlock(ip, lockflags);
+			if ((error = xfs_qm_dqget(mp, NULL, (xfs_dqid_t) uid,
+						 XFS_DQ_USER,
+						 XFS_QMOPT_DQALLOC |
+						 XFS_QMOPT_DOWARN,
+						 &uq))) {
+				ASSERT(error != ENOENT);
+				return (error);
+			}
+			/*
+			 * Get the ilock in the right order.
+			 */
+			xfs_dqunlock(uq);
+			lockflags = XFS_ILOCK_SHARED;
+			xfs_ilock(ip, lockflags);
+		} else {
+			/*
+			 * Take an extra reference, because we'll return
+			 * this to caller
+			 */
+			ASSERT(ip->i_udquot);
+			uq = ip->i_udquot;
+			xfs_dqlock(uq);
+			XFS_DQHOLD(uq);
+			xfs_dqunlock(uq);
+		}
+	}
+	if ((flags & XFS_QMOPT_GQUOTA) &&
+	    XFS_IS_GQUOTA_ON(mp)) {
+		if (ip->i_d.di_gid != gid) {
+			xfs_iunlock(ip, lockflags);
+			if ((error = xfs_qm_dqget(mp, NULL, (xfs_dqid_t)gid,
+						 XFS_DQ_GROUP,
+						 XFS_QMOPT_DQALLOC |
+						 XFS_QMOPT_DOWARN,
+						 &gq))) {
+				if (uq)
+					xfs_qm_dqrele(uq);
+				ASSERT(error != ENOENT);
+				return (error);
+			}
+			xfs_dqunlock(gq);
+			lockflags = XFS_ILOCK_SHARED;
+			xfs_ilock(ip, lockflags);
+		} else {
+			ASSERT(ip->i_gdquot);
+			gq = ip->i_gdquot;
+			xfs_dqlock(gq);
+			XFS_DQHOLD(gq);
+			xfs_dqunlock(gq);
+		}
+	}
+	if (uq)
+		xfs_dqtrace_entry_ino(uq, "DQALLOC", ip);
+
+	xfs_iunlock(ip, lockflags);
+	if (O_udqpp)
+		*O_udqpp = uq;
+	else if (uq)
+		xfs_qm_dqrele(uq);
+	if (O_gdqpp)
+		*O_gdqpp = gq;
+	else if (gq)
+		xfs_qm_dqrele(gq);
+	return (0);
+}
+
+/*
+ * Actually transfer ownership, and do dquot modifications.
+ * These were already reserved.
+ */
+xfs_dquot_t *
+xfs_qm_vop_chown(
+	xfs_trans_t	*tp,
+	xfs_inode_t	*ip,
+	xfs_dquot_t	**IO_olddq,
+	xfs_dquot_t	*newdq)
+{
+	xfs_dquot_t	*prevdq;
+	ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
+	ASSERT(XFS_IS_QUOTA_RUNNING(ip->i_mount));
+
+	/* old dquot */
+	prevdq = *IO_olddq;
+	ASSERT(prevdq);
+	ASSERT(prevdq != newdq);
+
+	xfs_trans_mod_dquot(tp, prevdq,
+			    XFS_TRANS_DQ_BCOUNT,
+			    -(ip->i_d.di_nblocks));
+	xfs_trans_mod_dquot(tp, prevdq,
+			    XFS_TRANS_DQ_ICOUNT,
+			    -1);
+
+	/* the sparkling new dquot */
+	xfs_trans_mod_dquot(tp, newdq,
+			    XFS_TRANS_DQ_BCOUNT,
+			    ip->i_d.di_nblocks);
+	xfs_trans_mod_dquot(tp, newdq,
+			    XFS_TRANS_DQ_ICOUNT,
+			    1);
+
+	/*
+	 * Take an extra reference, because the inode
+	 * is going to keep this dquot pointer even
+	 * after the trans_commit.
+	 */
+	xfs_dqlock(newdq);
+	XFS_DQHOLD(newdq);
+	xfs_dqunlock(newdq);
+	*IO_olddq = newdq;
+
+	return (prevdq);
+}
+
+/*
+ * Quota reservations for setattr(AT_UID|AT_GID).
+ */
+int
+xfs_qm_vop_chown_reserve(
+	xfs_trans_t	*tp,
+	xfs_inode_t	*ip,
+	xfs_dquot_t	*udqp,
+	xfs_dquot_t	*gdqp,
+	uint		flags)
+{
+	int		error;
+	xfs_mount_t	*mp;
+	uint		delblks;
+	xfs_dquot_t	*unresudq, *unresgdq, *delblksudq, *delblksgdq;
+
+	ASSERT(XFS_ISLOCKED_INODE(ip));
+	mp = ip->i_mount;
+	ASSERT(XFS_IS_QUOTA_RUNNING(mp));
+
+	delblks = ip->i_delayed_blks;
+	delblksudq = delblksgdq = unresudq = unresgdq = NULL;
+
+	if (XFS_IS_UQUOTA_ON(mp) && udqp &&
+	    ip->i_d.di_uid != (uid_t)INT_GET(udqp->q_core.d_id, ARCH_CONVERT)) {
+		delblksudq = udqp;
+		/*
+		 * If there are delayed allocation blocks, then we have to
+		 * unreserve those from the old dquot, and add them to the
+		 * new dquot.
+		 */
+		if (delblks) {
+			ASSERT(ip->i_udquot);
+			unresudq = ip->i_udquot;
+		}
+	}
+	if (XFS_IS_GQUOTA_ON(ip->i_mount) && gdqp &&
+	    ip->i_d.di_gid != INT_GET(gdqp->q_core.d_id, ARCH_CONVERT)) {
+		delblksgdq = gdqp;
+		if (delblks) {
+			ASSERT(ip->i_gdquot);
+			unresgdq = ip->i_gdquot;
+		}
+	}
+
+	if ((error = xfs_trans_reserve_quota_bydquots(tp, ip->i_mount,
+				delblksudq, delblksgdq, ip->i_d.di_nblocks, 1,
+				flags | XFS_QMOPT_RES_REGBLKS)))
+		return (error);
+
+	/*
+	 * Do the delayed blks reservations/unreservations now. Since, these
+	 * are done without the help of a transaction, if a reservation fails
+	 * its previous reservations won't be automatically undone by trans
+	 * code. So, we have to do it manually here.
+	 */
+	if (delblks) {
+		/*
+		 * Do the reservations first. Unreservation can't fail.
+		 */
+		ASSERT(delblksudq || delblksgdq);
+		ASSERT(unresudq || unresgdq);
+		if ((error = xfs_trans_reserve_quota_bydquots(NULL, ip->i_mount,
+				delblksudq, delblksgdq, (xfs_qcnt_t)delblks, 0,
+				flags | XFS_QMOPT_RES_REGBLKS)))
+			return (error);
+		xfs_trans_reserve_quota_bydquots(NULL, ip->i_mount,
+				unresudq, unresgdq, -((xfs_qcnt_t)delblks), 0,
+				XFS_QMOPT_RES_REGBLKS);
+	}
+
+	return (0);
+}
+
+int
+xfs_qm_vop_rename_dqattach(
+	xfs_inode_t	**i_tab)
+{
+	xfs_inode_t	*ip;
+	int		i;
+	int		error;
+
+	ip = i_tab[0];
+
+	if (! XFS_IS_QUOTA_ON(ip->i_mount))
+		return (0);
+
+	if (XFS_NOT_DQATTACHED(ip->i_mount, ip)) {
+		error = xfs_qm_dqattach(ip, 0);
+		if (error)
+			return (error);
+	}
+	for (i = 1; (i < 4 && i_tab[i]); i++) {
+		/*
+		 * Watch out for duplicate entries in the table.
+		 */
+		if ((ip = i_tab[i]) != i_tab[i-1]) {
+			if (XFS_NOT_DQATTACHED(ip->i_mount, ip)) {
+				error = xfs_qm_dqattach(ip, 0);
+				if (error)
+					return (error);
+			}
+		}
+	}
+	return (0);
+}
+
+void
+xfs_qm_vop_dqattach_and_dqmod_newinode(
+	xfs_trans_t	*tp,
+	xfs_inode_t	*ip,
+	xfs_dquot_t	*udqp,
+	xfs_dquot_t	*gdqp)
+{
+	if (!XFS_IS_QUOTA_ON(tp->t_mountp))
+		return;
+
+	ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
+	ASSERT(XFS_IS_QUOTA_RUNNING(tp->t_mountp));
+
+	if (udqp) {
+		xfs_dqlock(udqp);
+		XFS_DQHOLD(udqp);
+		xfs_dqunlock(udqp);
+		ASSERT(ip->i_udquot == NULL);
+		ip->i_udquot = udqp;
+		ASSERT(ip->i_d.di_uid == INT_GET(udqp->q_core.d_id, ARCH_CONVERT));
+		xfs_trans_mod_dquot(tp, udqp, XFS_TRANS_DQ_ICOUNT, 1);
+	}
+	if (gdqp) {
+		xfs_dqlock(gdqp);
+		XFS_DQHOLD(gdqp);
+		xfs_dqunlock(gdqp);
+		ASSERT(ip->i_gdquot == NULL);
+		ip->i_gdquot = gdqp;
+		ASSERT(ip->i_d.di_gid == INT_GET(gdqp->q_core.d_id, ARCH_CONVERT));
+		xfs_trans_mod_dquot(tp, gdqp, XFS_TRANS_DQ_ICOUNT, 1);
+	}
+}
+
+/* ------------- list stuff -----------------*/
+void
+xfs_qm_freelist_init(xfs_frlist_t *ql)
+{
+	ql->qh_next = ql->qh_prev = (xfs_dquot_t *) ql;
+	mutex_init(&ql->qh_lock, MUTEX_DEFAULT, "dqf");
+	ql->qh_version = 0;
+	ql->qh_nelems = 0;
+}
+
+void
+xfs_qm_freelist_destroy(xfs_frlist_t *ql)
+{
+	xfs_dquot_t	*dqp, *nextdqp;
+
+	mutex_lock(&ql->qh_lock, PINOD);
+	for (dqp = ql->qh_next;
+	     dqp != (xfs_dquot_t *)ql; ) {
+		xfs_dqlock(dqp);
+		nextdqp = dqp->dq_flnext;
+#ifdef QUOTADEBUG
+		cmn_err(CE_DEBUG, "FREELIST destroy 0x%p", dqp);
+#endif
+		XQM_FREELIST_REMOVE(dqp);
+		xfs_dqunlock(dqp);
+		xfs_qm_dqdestroy(dqp);
+		dqp = nextdqp;
+	}
+	/*
+	 * Don't bother about unlocking.
+	 */
+	mutex_destroy(&ql->qh_lock);
+
+	ASSERT(ql->qh_nelems == 0);
+}
+
+void
+xfs_qm_freelist_insert(xfs_frlist_t *ql, xfs_dquot_t *dq)
+{
+	dq->dq_flnext = ql->qh_next;
+	dq->dq_flprev = (xfs_dquot_t *)ql;
+	ql->qh_next = dq;
+	dq->dq_flnext->dq_flprev = dq;
+	xfs_Gqm->qm_dqfreelist.qh_nelems++;
+	xfs_Gqm->qm_dqfreelist.qh_version++;
+}
+
+void
+xfs_qm_freelist_unlink(xfs_dquot_t *dq)
+{
+	xfs_dquot_t *next = dq->dq_flnext;
+	xfs_dquot_t *prev = dq->dq_flprev;
+
+	next->dq_flprev = prev;
+	prev->dq_flnext = next;
+	dq->dq_flnext = dq->dq_flprev = dq;
+	xfs_Gqm->qm_dqfreelist.qh_nelems--;
+	xfs_Gqm->qm_dqfreelist.qh_version++;
+}
+
+void
+xfs_qm_freelist_append(xfs_frlist_t *ql, xfs_dquot_t *dq)
+{
+	xfs_qm_freelist_insert((xfs_frlist_t *)ql->qh_prev, dq);
+}
+
+int
+xfs_qm_dqhashlock_nowait(
+	xfs_dquot_t *dqp)
+{
+	int locked;
+
+	locked = mutex_trylock(&((dqp)->q_hash->qh_lock));
+	return (locked);
+}
+
+int
+xfs_qm_freelist_lock_nowait(
+	xfs_qm_t *xqm)
+{
+	int locked;
+
+	locked = mutex_trylock(&(xqm->qm_dqfreelist.qh_lock));
+	return (locked);
+}
+
+int
+xfs_qm_mplist_nowait(
+	xfs_mount_t	*mp)
+{
+	int locked;
+
+	ASSERT(mp->m_quotainfo);
+	locked = mutex_trylock(&(XFS_QI_MPLLOCK(mp)));
+	return (locked);
+}

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)