/*

   * Copyright (c) 2000-2005 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_shared.h"

  #include "xfs_format.h"

  #include "xfs_log_format.h"

  #include "xfs_trans_resv.h"

  #include "xfs_bit.h"

  #include "xfs_sb.h"

  #include "xfs_mount.h"

  #include "xfs_inode.h"

  #include "xfs_ialloc.h"
  #include "xfs_itable.h"

  #include "xfs_quota.h"

  #include "xfs_error.h"

  #include "xfs_bmap.h"

  #include "xfs_bmap_btree.h"

  #include "xfs_trans.h"

  #include "xfs_trans_space.h"

  #include "xfs_qm.h"

  #include "xfs_trace.h"

  #include "xfs_icache.h"

  #include "xfs_cksum.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.
   */

  STATIC int	xfs_qm_init_quotainos(xfs_mount_t *);

  STATIC int	xfs_qm_init_quotainfo(xfs_mount_t *);

  
  STATIC void	xfs_qm_dqfree_one(struct xfs_dquot *dqp);

  /*

   * We use the batch lookup interface to iterate over the dquots as it
   * currently is the only interface into the radix tree code that allows
   * fuzzy lookups instead of exact matches.  Holding the lock over multiple
   * operations is fine as all callers are used either during mount/umount
   * or quotaoff.
   */
  #define XFS_DQ_LOOKUP_BATCH	32
  
  STATIC int
  xfs_qm_dquot_walk(
  	struct xfs_mount	*mp,
  	int			type,

  	int			(*execute)(struct xfs_dquot *dqp, void *data),
  	void			*data)

  {
  	struct xfs_quotainfo	*qi = mp->m_quotainfo;

  	struct radix_tree_root	*tree = xfs_dquot_tree(qi, type);

  	uint32_t		next_index;
  	int			last_error = 0;
  	int			skipped;
  	int			nr_found;
  
  restart:
  	skipped = 0;
  	next_index = 0;
  	nr_found = 0;
  
  	while (1) {
  		struct xfs_dquot *batch[XFS_DQ_LOOKUP_BATCH];
  		int		error = 0;
  		int		i;
  
  		mutex_lock(&qi->qi_tree_lock);
  		nr_found = radix_tree_gang_lookup(tree, (void **)batch,
  					next_index, XFS_DQ_LOOKUP_BATCH);
  		if (!nr_found) {
  			mutex_unlock(&qi->qi_tree_lock);
  			break;
  		}
  
  		for (i = 0; i < nr_found; i++) {
  			struct xfs_dquot *dqp = batch[i];
  
  			next_index = be32_to_cpu(dqp->q_core.d_id) + 1;

  			error = execute(batch[i], data);

  			if (error == -EAGAIN) {

  				skipped++;
  				continue;
  			}

  			if (error && last_error != -EFSCORRUPTED)

  				last_error = error;
  		}
  
  		mutex_unlock(&qi->qi_tree_lock);
  
  		/* bail out if the filesystem is corrupted.  */

  		if (last_error == -EFSCORRUPTED) {

  			skipped = 0;
  			break;
  		}
  	}
  
  	if (skipped) {
  		delay(1);
  		goto restart;
  	}
  
  	return last_error;
  }
  
  
  /*
   * Purge a dquot from all tracking data structures and free it.
   */
  STATIC int
  xfs_qm_dqpurge(

  	struct xfs_dquot	*dqp,
  	void			*data)

  {
  	struct xfs_mount	*mp = dqp->q_mount;
  	struct xfs_quotainfo	*qi = mp->m_quotainfo;

  
  	xfs_dqlock(dqp);
  	if ((dqp->dq_flags & XFS_DQ_FREEING) || dqp->q_nrefs != 0) {
  		xfs_dqunlock(dqp);

  		return -EAGAIN;

  	}

  	dqp->dq_flags |= XFS_DQ_FREEING;

  	xfs_dqflock(dqp);

  
  	/*
  	 * If we are turning this type of quotas off, we don't care
  	 * about the dirty metadata sitting in this dquot. OTOH, if
  	 * we're unmounting, we do care, so we flush it and wait.
  	 */
  	if (XFS_DQ_IS_DIRTY(dqp)) {

  		struct xfs_buf	*bp = NULL;
  		int		error;

  
  		/*
  		 * We don't care about getting disk errors here. We need
  		 * to purge this dquot anyway, so we go ahead regardless.
  		 */

  		error = xfs_qm_dqflush(dqp, &bp);
  		if (error) {

  			xfs_warn(mp, "%s: dquot %p flush failed",
  				__func__, dqp);

  		} else {
  			error = xfs_bwrite(bp);
  			xfs_buf_relse(bp);
  		}

  		xfs_dqflock(dqp);
  	}
  
  	ASSERT(atomic_read(&dqp->q_pincount) == 0);
  	ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
  	       !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));
  
  	xfs_dqfunlock(dqp);
  	xfs_dqunlock(dqp);

  	radix_tree_delete(xfs_dquot_tree(qi, dqp->q_core.d_flags),

  			  be32_to_cpu(dqp->q_core.d_id));
  	qi->qi_dquots--;
  
  	/*
  	 * We move dquots to the freelist as soon as their reference count
  	 * hits zero, so it really should be on the freelist here.
  	 */

  	ASSERT(!list_empty(&dqp->q_lru));

  	list_lru_del(&qi->qi_lru, &dqp->q_lru);

  	XFS_STATS_DEC(mp, xs_qm_dquot_unused);

  
  	xfs_qm_dqdestroy(dqp);

  	return 0;
  }
  
  /*

   * Purge the dquot cache.
   */
  void
  xfs_qm_dqpurge_all(
  	struct xfs_mount	*mp,
  	uint			flags)
  {

  	if (flags & XFS_QMOPT_UQUOTA)
  		xfs_qm_dquot_walk(mp, XFS_DQ_USER, xfs_qm_dqpurge, NULL);

  	if (flags & XFS_QMOPT_GQUOTA)

  		xfs_qm_dquot_walk(mp, XFS_DQ_GROUP, xfs_qm_dqpurge, NULL);

  	if (flags & XFS_QMOPT_PQUOTA)

  		xfs_qm_dquot_walk(mp, XFS_DQ_PROJ, xfs_qm_dqpurge, NULL);

  }
  
  /*

   * Just destroy the quotainfo structure.
   */
  void

  xfs_qm_unmount(
  	struct xfs_mount	*mp)

  {

  	if (mp->m_quotainfo) {

  		xfs_qm_dqpurge_all(mp, XFS_QMOPT_QUOTALL);

  		xfs_qm_destroy_quotainfo(mp);

  	}

  }

  /*
   * Called from the vfsops layer.
   */

  void

  xfs_qm_unmount_quotas(
  	xfs_mount_t	*mp)
  {

  	/*
  	 * 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);
  
  	/*

  	 * Release the quota inodes.

  	 */

  	if (mp->m_quotainfo) {

  		if (mp->m_quotainfo->qi_uquotaip) {
  			IRELE(mp->m_quotainfo->qi_uquotaip);
  			mp->m_quotainfo->qi_uquotaip = NULL;

  		}

  		if (mp->m_quotainfo->qi_gquotaip) {
  			IRELE(mp->m_quotainfo->qi_gquotaip);
  			mp->m_quotainfo->qi_gquotaip = NULL;

  		}

  		if (mp->m_quotainfo->qi_pquotaip) {
  			IRELE(mp->m_quotainfo->qi_pquotaip);
  			mp->m_quotainfo->qi_pquotaip = NULL;
  		}

  	}

  }

  STATIC int
  xfs_qm_dqattach_one(
  	xfs_inode_t	*ip,
  	xfs_dqid_t	id,
  	uint		type,
  	uint		doalloc,

  	xfs_dquot_t	**IO_idqpp)
  {
  	xfs_dquot_t	*dqp;
  	int		error;

  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));

  	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.

  	 */

  	dqp = *IO_idqpp;
  	if (dqp) {

  		trace_xfs_dqattach_found(dqp);

  		return 0;

  	}
  
  	/*

  	 * 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.

  	 */

  	error = xfs_qm_dqget(ip->i_mount, ip, id, type,
  			     doalloc | XFS_QMOPT_DOWARN, &dqp);

  	if (error)
  		return error;

  	trace_xfs_dqattach_get(dqp);

  	/*
  	 * 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;

  	xfs_dqunlock(dqp);
  	return 0;

  }

  static bool
  xfs_qm_need_dqattach(
  	struct xfs_inode	*ip)
  {
  	struct xfs_mount	*mp = ip->i_mount;
  
  	if (!XFS_IS_QUOTA_RUNNING(mp))
  		return false;
  	if (!XFS_IS_QUOTA_ON(mp))
  		return false;
  	if (!XFS_NOT_DQATTACHED(mp, ip))
  		return false;

  	if (xfs_is_quota_inode(&mp->m_sb, ip->i_ino))

  		return false;
  	return true;
  }

  
  /*

   * Given a locked inode, attach dquot(s) to it, taking U/G/P-QUOTAON
   * into account.

   * If XFS_QMOPT_DQALLOC, the dquot(s) will be allocated if needed.

   * Inode may get unlocked and relocked in here, and the caller must deal with
   * the consequences.
   */
  int

  xfs_qm_dqattach_locked(

  	xfs_inode_t	*ip,
  	uint		flags)
  {
  	xfs_mount_t	*mp = ip->i_mount;

  	int		error = 0;

  	if (!xfs_qm_need_dqattach(ip))

  		return 0;

  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));

  	if (XFS_IS_UQUOTA_ON(mp) && !ip->i_udquot) {

  		error = xfs_qm_dqattach_one(ip, ip->i_d.di_uid, XFS_DQ_USER,
  						flags & XFS_QMOPT_DQALLOC,

  						&ip->i_udquot);

  		if (error)
  			goto done;

  		ASSERT(ip->i_udquot);

  	}

  	if (XFS_IS_GQUOTA_ON(mp) && !ip->i_gdquot) {

  		error = xfs_qm_dqattach_one(ip, ip->i_d.di_gid, XFS_DQ_GROUP,

  						flags & XFS_QMOPT_DQALLOC,

  						&ip->i_gdquot);

  		if (error)
  			goto done;

  		ASSERT(ip->i_gdquot);

  	}

  	if (XFS_IS_PQUOTA_ON(mp) && !ip->i_pdquot) {

  		error = xfs_qm_dqattach_one(ip, xfs_get_projid(ip), XFS_DQ_PROJ,
  						flags & XFS_QMOPT_DQALLOC,

  						&ip->i_pdquot);

  		if (error)
  			goto done;

  		ASSERT(ip->i_pdquot);

  	}

  done:

  	/*

  	 * Don't worry about the dquots that we may have attached before any
  	 * error - they'll get detached later if it has not already been done.

  	 */

  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));

  	return error;
  }

  int
  xfs_qm_dqattach(
  	struct xfs_inode	*ip,
  	uint			flags)
  {
  	int			error;

  	if (!xfs_qm_need_dqattach(ip))
  		return 0;

  	xfs_ilock(ip, XFS_ILOCK_EXCL);
  	error = xfs_qm_dqattach_locked(ip, flags);
  	xfs_iunlock(ip, XFS_ILOCK_EXCL);

  	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 || ip->i_pdquot))

  		return;

  	trace_xfs_dquot_dqdetach(ip);

  	ASSERT(!xfs_is_quota_inode(&ip->i_mount->m_sb, ip->i_ino));

  	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;
  	}

  	if (ip->i_pdquot) {
  		xfs_qm_dqrele(ip->i_pdquot);
  		ip->i_pdquot = NULL;
  	}

  }

  struct xfs_qm_isolate {
  	struct list_head	buffers;
  	struct list_head	dispose;
  };
  
  static enum lru_status
  xfs_qm_dquot_isolate(
  	struct list_head	*item,

  	struct list_lru_one	*lru,

  	spinlock_t		*lru_lock,
  	void			*arg)

  		__releases(lru_lock) __acquires(lru_lock)

  {
  	struct xfs_dquot	*dqp = container_of(item,
  						struct xfs_dquot, q_lru);
  	struct xfs_qm_isolate	*isol = arg;
  
  	if (!xfs_dqlock_nowait(dqp))
  		goto out_miss_busy;
  
  	/*
  	 * This dquot has acquired a reference in the meantime remove it from
  	 * the freelist and try again.
  	 */
  	if (dqp->q_nrefs) {
  		xfs_dqunlock(dqp);

  		XFS_STATS_INC(dqp->q_mount, xs_qm_dqwants);

  
  		trace_xfs_dqreclaim_want(dqp);

  		list_lru_isolate(lru, &dqp->q_lru);

  		XFS_STATS_DEC(dqp->q_mount, xs_qm_dquot_unused);

  		return LRU_REMOVED;

  	}
  
  	/*
  	 * If the dquot is dirty, flush it. If it's already being flushed, just
  	 * skip it so there is time for the IO to complete before we try to
  	 * reclaim it again on the next LRU pass.
  	 */
  	if (!xfs_dqflock_nowait(dqp)) {
  		xfs_dqunlock(dqp);
  		goto out_miss_busy;
  	}
  
  	if (XFS_DQ_IS_DIRTY(dqp)) {
  		struct xfs_buf	*bp = NULL;
  		int		error;
  
  		trace_xfs_dqreclaim_dirty(dqp);
  
  		/* we have to drop the LRU lock to flush the dquot */
  		spin_unlock(lru_lock);
  
  		error = xfs_qm_dqflush(dqp, &bp);
  		if (error) {
  			xfs_warn(dqp->q_mount, "%s: dquot %p flush failed",
  				 __func__, dqp);
  			goto out_unlock_dirty;
  		}
  
  		xfs_buf_delwri_queue(bp, &isol->buffers);
  		xfs_buf_relse(bp);
  		goto out_unlock_dirty;
  	}
  	xfs_dqfunlock(dqp);
  
  	/*
  	 * Prevent lookups now that we are past the point of no return.
  	 */
  	dqp->dq_flags |= XFS_DQ_FREEING;
  	xfs_dqunlock(dqp);
  
  	ASSERT(dqp->q_nrefs == 0);

  	list_lru_isolate_move(lru, &dqp->q_lru, &isol->dispose);

  	XFS_STATS_DEC(dqp->q_mount, xs_qm_dquot_unused);

  	trace_xfs_dqreclaim_done(dqp);

  	XFS_STATS_INC(dqp->q_mount, xs_qm_dqreclaims);

  	return LRU_REMOVED;

  
  out_miss_busy:
  	trace_xfs_dqreclaim_busy(dqp);

  	XFS_STATS_INC(dqp->q_mount, xs_qm_dqreclaim_misses);

  	return LRU_SKIP;

  
  out_unlock_dirty:
  	trace_xfs_dqreclaim_busy(dqp);

  	XFS_STATS_INC(dqp->q_mount, xs_qm_dqreclaim_misses);

  	xfs_dqunlock(dqp);
  	spin_lock(lru_lock);
  	return LRU_RETRY;

  }

  static unsigned long

  xfs_qm_shrink_scan(
  	struct shrinker		*shrink,
  	struct shrink_control	*sc)
  {
  	struct xfs_quotainfo	*qi = container_of(shrink,
  					struct xfs_quotainfo, qi_shrinker);
  	struct xfs_qm_isolate	isol;

  	unsigned long		freed;

  	int			error;

  	if ((sc->gfp_mask & (__GFP_FS|__GFP_DIRECT_RECLAIM)) != (__GFP_FS|__GFP_DIRECT_RECLAIM))

  		return 0;
  
  	INIT_LIST_HEAD(&isol.buffers);
  	INIT_LIST_HEAD(&isol.dispose);

  	freed = list_lru_shrink_walk(&qi->qi_lru, sc,
  				     xfs_qm_dquot_isolate, &isol);

  
  	error = xfs_buf_delwri_submit(&isol.buffers);
  	if (error)
  		xfs_warn(NULL, "%s: dquot reclaim failed", __func__);
  
  	while (!list_empty(&isol.dispose)) {
  		struct xfs_dquot	*dqp;
  
  		dqp = list_first_entry(&isol.dispose, struct xfs_dquot, q_lru);
  		list_del_init(&dqp->q_lru);
  		xfs_qm_dqfree_one(dqp);
  	}
  
  	return freed;
  }

  static unsigned long

  xfs_qm_shrink_count(
  	struct shrinker		*shrink,
  	struct shrink_control	*sc)
  {
  	struct xfs_quotainfo	*qi = container_of(shrink,
  					struct xfs_quotainfo, qi_shrinker);

  	return list_lru_shrink_count(&qi->qi_lru, sc);

  }

  STATIC void
  xfs_qm_set_defquota(
  	xfs_mount_t	*mp,
  	uint		type,
  	xfs_quotainfo_t	*qinf)
  {
  	xfs_dquot_t		*dqp;
  	struct xfs_def_quota    *defq;
  	int			error;
  
  	error = xfs_qm_dqread(mp, 0, type, XFS_QMOPT_DOWARN, &dqp);
  
  	if (!error) {
  		xfs_disk_dquot_t        *ddqp = &dqp->q_core;
  
  		defq = xfs_get_defquota(dqp, qinf);
  
  		/*
  		 * Timers and warnings have been already set, let's just set the
  		 * default limits for this quota type
  		 */
  		defq->bhardlimit = be64_to_cpu(ddqp->d_blk_hardlimit);
  		defq->bsoftlimit = be64_to_cpu(ddqp->d_blk_softlimit);
  		defq->ihardlimit = be64_to_cpu(ddqp->d_ino_hardlimit);
  		defq->isoftlimit = be64_to_cpu(ddqp->d_ino_softlimit);
  		defq->rtbhardlimit = be64_to_cpu(ddqp->d_rtb_hardlimit);
  		defq->rtbsoftlimit = be64_to_cpu(ddqp->d_rtb_softlimit);
  		xfs_qm_dqdestroy(dqp);
  	}
  }

  /*

   * This initializes all the quota information that's kept in the
   * mount structure
   */

  STATIC 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));

  	qinf = mp->m_quotainfo = kmem_zalloc(sizeof(xfs_quotainfo_t), KM_SLEEP);

  	error = list_lru_init(&qinf->qi_lru);

  	if (error)
  		goto out_free_qinf;

  	/*
  	 * See if quotainodes are setup, and if not, allocate them,
  	 * and change the superblock accordingly.
  	 */

  	error = xfs_qm_init_quotainos(mp);
  	if (error)
  		goto out_free_lru;

  	INIT_RADIX_TREE(&qinf->qi_uquota_tree, GFP_NOFS);
  	INIT_RADIX_TREE(&qinf->qi_gquota_tree, GFP_NOFS);

  	INIT_RADIX_TREE(&qinf->qi_pquota_tree, GFP_NOFS);

  	mutex_init(&qinf->qi_tree_lock);

  	/* mutex used to serialize quotaoffs */

  	mutex_init(&qinf->qi_quotaofflock);

  
  	/* Precalc some constants */
  	qinf->qi_dqchunklen = XFS_FSB_TO_BB(mp, XFS_DQUOT_CLUSTER_SIZE_FSB);

  	qinf->qi_dqperchunk = xfs_calc_dquots_per_chunk(qinf->qi_dqchunklen);

  
  	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.

  	 *

  	 * Since we may not have done a quotacheck by this point, just read
  	 * the dquot without attaching it to any hashtables or lists.

  	 *
  	 * Timers and warnings are globally set by the first timer found in
  	 * user/group/proj quota types, otherwise a default value is used.
  	 * This should be split into different fields per quota type.

  	 */

  	error = xfs_qm_dqread(mp, 0,
  			XFS_IS_UQUOTA_RUNNING(mp) ? XFS_DQ_USER :
  			 (XFS_IS_GQUOTA_RUNNING(mp) ? XFS_DQ_GROUP :
  			  XFS_DQ_PROJ),
  			XFS_QMOPT_DOWARN, &dqp);

  	if (!error) {

  		xfs_disk_dquot_t	*ddqp = &dqp->q_core;
  
  		/*
  		 * 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 = ddqp->d_btimer ?
  			be32_to_cpu(ddqp->d_btimer) : XFS_QM_BTIMELIMIT;
  		qinf->qi_itimelimit = ddqp->d_itimer ?
  			be32_to_cpu(ddqp->d_itimer) : XFS_QM_ITIMELIMIT;
  		qinf->qi_rtbtimelimit = ddqp->d_rtbtimer ?
  			be32_to_cpu(ddqp->d_rtbtimer) : XFS_QM_RTBTIMELIMIT;
  		qinf->qi_bwarnlimit = ddqp->d_bwarns ?
  			be16_to_cpu(ddqp->d_bwarns) : XFS_QM_BWARNLIMIT;
  		qinf->qi_iwarnlimit = ddqp->d_iwarns ?
  			be16_to_cpu(ddqp->d_iwarns) : XFS_QM_IWARNLIMIT;
  		qinf->qi_rtbwarnlimit = ddqp->d_rtbwarns ?
  			be16_to_cpu(ddqp->d_rtbwarns) : XFS_QM_RTBWARNLIMIT;

  		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;

  		qinf->qi_rtbwarnlimit = XFS_QM_RTBWARNLIMIT;

  	}

  	if (XFS_IS_UQUOTA_RUNNING(mp))
  		xfs_qm_set_defquota(mp, XFS_DQ_USER, qinf);
  	if (XFS_IS_GQUOTA_RUNNING(mp))
  		xfs_qm_set_defquota(mp, XFS_DQ_GROUP, qinf);
  	if (XFS_IS_PQUOTA_RUNNING(mp))
  		xfs_qm_set_defquota(mp, XFS_DQ_PROJ, qinf);

  	qinf->qi_shrinker.count_objects = xfs_qm_shrink_count;
  	qinf->qi_shrinker.scan_objects = xfs_qm_shrink_scan;

  	qinf->qi_shrinker.seeks = DEFAULT_SEEKS;

  	qinf->qi_shrinker.flags = SHRINKER_NUMA_AWARE;

  	register_shrinker(&qinf->qi_shrinker);

  	return 0;

  
  out_free_lru:
  	list_lru_destroy(&qinf->qi_lru);
  out_free_qinf:
  	kmem_free(qinf);
  	mp->m_quotainfo = NULL;
  	return error;

  }
  
  
  /*
   * 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);

  	unregister_shrinker(&qi->qi_shrinker);

  	list_lru_destroy(&qi->qi_lru);

  	if (qi->qi_uquotaip) {

  		IRELE(qi->qi_uquotaip);

  		qi->qi_uquotaip = NULL; /* paranoia */
  	}
  	if (qi->qi_gquotaip) {

  		IRELE(qi->qi_gquotaip);

  		qi->qi_gquotaip = NULL;
  	}

  	if (qi->qi_pquotaip) {
  		IRELE(qi->qi_pquotaip);
  		qi->qi_pquotaip = NULL;
  	}

  	mutex_destroy(&qi->qi_quotaofflock);

  	kmem_free(qi);

  	mp->m_quotainfo = NULL;
  }

  /*
   * 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,

  	uint		flags)
  {
  	xfs_trans_t	*tp;
  	int		error;

  	int		committed;

  	bool		need_alloc = true;

  	*ip = NULL;
  	/*
  	 * With superblock that doesn't have separate pquotino, we
  	 * share an inode between gquota and pquota. If the on-disk
  	 * superblock has GQUOTA and the filesystem is now mounted
  	 * with PQUOTA, just use sb_gquotino for sb_pquotino and
  	 * vice-versa.
  	 */
  	if (!xfs_sb_version_has_pquotino(&mp->m_sb) &&
  			(flags & (XFS_QMOPT_PQUOTA|XFS_QMOPT_GQUOTA))) {
  		xfs_ino_t ino = NULLFSINO;
  
  		if ((flags & XFS_QMOPT_PQUOTA) &&
  			     (mp->m_sb.sb_gquotino != NULLFSINO)) {
  			ino = mp->m_sb.sb_gquotino;
  			ASSERT(mp->m_sb.sb_pquotino == NULLFSINO);
  		} else if ((flags & XFS_QMOPT_GQUOTA) &&
  			     (mp->m_sb.sb_pquotino != NULLFSINO)) {
  			ino = mp->m_sb.sb_pquotino;
  			ASSERT(mp->m_sb.sb_gquotino == NULLFSINO);
  		}
  		if (ino != NULLFSINO) {
  			error = xfs_iget(mp, NULL, ino, 0, 0, ip);
  			if (error)
  				return error;
  			mp->m_sb.sb_gquotino = NULLFSINO;
  			mp->m_sb.sb_pquotino = NULLFSINO;

  			need_alloc = false;

  		}
  	}

  	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_create,
  			XFS_QM_QINOCREATE_SPACE_RES(mp), 0, 0, &tp);
  	if (error)

  		return error;

  	if (need_alloc) {

  		error = xfs_dir_ialloc(&tp, NULL, S_IFREG, 1, 0, 0, 1, ip,
  								&committed);
  		if (error) {

  			xfs_trans_cancel(tp);

  			return error;
  		}

  	}
  
  	/*

  	 * Make the changes in the superblock, and log those too.
  	 * sbfields arg may contain fields other than *QUOTINO;
  	 * VERSIONNUM for example.
  	 */

  	spin_lock(&mp->m_sb_lock);

  	if (flags & XFS_QMOPT_SBVERSION) {

  		ASSERT(!xfs_sb_version_hasquota(&mp->m_sb));

  		xfs_sb_version_addquota(&mp->m_sb);

  		mp->m_sb.sb_uquotino = NULLFSINO;
  		mp->m_sb.sb_gquotino = NULLFSINO;

  		mp->m_sb.sb_pquotino = NULLFSINO;

  		/* qflags will get updated fully _after_ quotacheck */
  		mp->m_sb.sb_qflags = mp->m_qflags & XFS_ALL_QUOTA_ACCT;

  	}
  	if (flags & XFS_QMOPT_UQUOTA)
  		mp->m_sb.sb_uquotino = (*ip)->i_ino;

  	else if (flags & XFS_QMOPT_GQUOTA)

  		mp->m_sb.sb_gquotino = (*ip)->i_ino;

  	else
  		mp->m_sb.sb_pquotino = (*ip)->i_ino;

  	spin_unlock(&mp->m_sb_lock);

  	xfs_log_sb(tp);

  	error = xfs_trans_commit(tp);

  	if (error) {
  		ASSERT(XFS_FORCED_SHUTDOWN(mp));

  		xfs_alert(mp, "%s failed (error %d)!", __func__, error);

  	}

  	if (need_alloc)
  		xfs_finish_inode_setup(*ip);
  	return error;

  }

  STATIC void

  xfs_qm_reset_dqcounts(
  	xfs_mount_t	*mp,
  	xfs_buf_t	*bp,
  	xfs_dqid_t	id,
  	uint		type)
  {

  	struct xfs_dqblk	*dqb;

  	int			j;

  	trace_xfs_reset_dqcounts(bp, _RET_IP_);

  	/*
  	 * 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(mp->m_quotainfo->qi_dqperchunk == j);

  #endif

  	dqb = bp->b_addr;

  	for (j = 0; j < mp->m_quotainfo->qi_dqperchunk; j++) {

  		struct xfs_disk_dquot	*ddq;
  
  		ddq = (struct xfs_disk_dquot *)&dqb[j];

  		/*
  		 * Do a sanity check, and if needed, repair the dqblk. Don't
  		 * output any warnings because it's perfectly possible to

  		 * find uninitialised dquot blks. See comment in xfs_dqcheck.

  		 */

  		xfs_dqcheck(mp, ddq, id+j, type, XFS_QMOPT_DQREPAIR,
  			    "xfs_quotacheck");

  		/*
  		 * Reset type in case we are reusing group quota file for
  		 * project quotas or vice versa
  		 */
  		ddq->d_flags = type;

  		ddq->d_bcount = 0;
  		ddq->d_icount = 0;
  		ddq->d_rtbcount = 0;
  		ddq->d_btimer = 0;
  		ddq->d_itimer = 0;
  		ddq->d_rtbtimer = 0;
  		ddq->d_bwarns = 0;
  		ddq->d_iwarns = 0;
  		ddq->d_rtbwarns = 0;

  
  		if (xfs_sb_version_hascrc(&mp->m_sb)) {
  			xfs_update_cksum((char *)&dqb[j],
  					 sizeof(struct xfs_dqblk),
  					 XFS_DQUOT_CRC_OFF);
  		}

  	}

  }
  
  STATIC int
  xfs_qm_dqiter_bufs(

  	struct xfs_mount	*mp,
  	xfs_dqid_t		firstid,
  	xfs_fsblock_t		bno,
  	xfs_filblks_t		blkcnt,
  	uint			flags,
  	struct list_head	*buffer_list)

  {

  	struct xfs_buf		*bp;
  	int			error;
  	int			type;

  
  	ASSERT(blkcnt > 0);

  	type = flags & XFS_QMOPT_UQUOTA ? XFS_DQ_USER :
  		(flags & XFS_QMOPT_PQUOTA ? XFS_DQ_PROJ : XFS_DQ_GROUP);

  	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),

  			      mp->m_quotainfo->qi_dqchunklen, 0, &bp,

  			      &xfs_dquot_buf_ops);

  		/*

  		 * CRC and validation errors will return a EFSCORRUPTED here. If
  		 * this occurs, re-read without CRC validation so that we can
  		 * repair the damage via xfs_qm_reset_dqcounts(). This process
  		 * will leave a trace in the log indicating corruption has
  		 * been detected.

  		 */

  		if (error == -EFSCORRUPTED) {

  			error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
  				      XFS_FSB_TO_DADDR(mp, bno),
  				      mp->m_quotainfo->qi_dqchunklen, 0, &bp,
  				      NULL);
  		}
  
  		if (error)
  			break;

  		/*
  		 * A corrupt buffer might not have a verifier attached, so
  		 * make sure we have the correct one attached before writeback
  		 * occurs.
  		 */
  		bp->b_ops = &xfs_dquot_buf_ops;

  		xfs_qm_reset_dqcounts(mp, bp, firstid, type);

  		xfs_buf_delwri_queue(bp, buffer_list);

  		xfs_buf_relse(bp);

  
  		/* goto the next block. */

  		bno++;

  		firstid += mp->m_quotainfo->qi_dqperchunk;

  	}

  	return error;

  }
  
  /*

   * Iterate over all allocated USR/GRP/PRJ dquots in the system, calling a

   * caller supplied function for every chunk of dquots that we find.
   */
  STATIC int
  xfs_qm_dqiterate(

  	struct xfs_mount	*mp,
  	struct xfs_inode	*qip,
  	uint			flags,
  	struct list_head	*buffer_list)

  {

  	struct xfs_bmbt_irec	*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 racy, 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, mp->m_super->s_maxbytes);

  	do {

  		uint		lock_mode;

  		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.
  		 */

  		lock_mode = xfs_ilock_data_map_shared(qip);

  		error = xfs_bmapi_read(qip, lblkno, maxlblkcnt - lblkno,
  				       map, &nmaps, 0);

  		xfs_iunlock(qip, lock_mode);

  		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 *

  				mp->m_quotainfo->qi_dqperchunk;

  			/*
  			 * 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_buf_readahead(mp->m_ddev_targp,

  					       XFS_FSB_TO_DADDR(mp, rablkno),

  					       mp->m_quotainfo->qi_dqchunklen,

  					       &xfs_dquot_buf_ops);

  					rablkno++;
  				}
  			}
  			/*
  			 * Iterate thru all the blks in the extent and
  			 * reset the counters of all the dquots inside them.
  			 */

  			error = xfs_qm_dqiter_bufs(mp, firstid,
  						   map[i].br_startblock,
  						   map[i].br_blockcount,
  						   flags, buffer_list);
  			if (error)
  				goto out;

  		}

  	} while (nmaps > 0);

  out:

  	kmem_free(map);

  	return error;

  }
  
  /*
   * Called by dqusage_adjust in doing a quotacheck.

   *
   * Given the inode, and a dquot id this updates both the incore dqout 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 int

  xfs_qm_quotacheck_dqadjust(

  	struct xfs_inode	*ip,
  	xfs_dqid_t		id,
  	uint			type,

  	xfs_qcnt_t		nblks,
  	xfs_qcnt_t		rtblks)
  {

  	struct xfs_mount	*mp = ip->i_mount;
  	struct xfs_dquot	*dqp;
  	int			error;
  
  	error = xfs_qm_dqget(mp, ip, id, type,
  			     XFS_QMOPT_DQALLOC | XFS_QMOPT_DOWARN, &dqp);
  	if (error) {
  		/*
  		 * Shouldn't be able to turn off quotas here.
  		 */

  		ASSERT(error != -ESRCH);
  		ASSERT(error != -ENOENT);

  		return error;
  	}

  
  	trace_xfs_dqadjust(dqp);

  	/*
  	 * Adjust the inode count and the block count to reflect this inode's
  	 * resource usage.
  	 */

  	be64_add_cpu(&dqp->q_core.d_icount, 1);

  	dqp->q_res_icount++;
  	if (nblks) {

  		be64_add_cpu(&dqp->q_core.d_bcount, nblks);

  		dqp->q_res_bcount += nblks;
  	}
  	if (rtblks) {

  		be64_add_cpu(&dqp->q_core.d_rtbcount, rtblks);

  		dqp->q_res_rtbcount += rtblks;
  	}
  
  	/*
  	 * Set default limits, adjust timers (since we changed usages)

  	 *
  	 * There are no timers for the default values set in the root dquot.

  	 */

  	if (dqp->q_core.d_id) {

  		xfs_qm_adjust_dqlimits(mp, dqp);

  		xfs_qm_adjust_dqtimers(mp, &dqp->q_core);

  	}
  
  	dqp->dq_flags |= XFS_DQ_DIRTY;

  	xfs_qm_dqput(dqp);
  	return 0;

  }
  
  STATIC int
  xfs_qm_get_rtblks(
  	xfs_inode_t	*ip,
  	xfs_qcnt_t	*O_rtblks)
  {
  	xfs_filblks_t	rtblks;			/* total rt blks */

  	xfs_extnum_t	idx;			/* extent record index */

  	xfs_ifork_t	*ifp;			/* inode fork pointer */
  	xfs_extnum_t	nextents;		/* number of extent entries */

  	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 / (uint)sizeof(xfs_bmbt_rec_t);

  	for (idx = 0; idx < nextents; idx++)
  		rtblks += xfs_bmbt_get_blockcount(xfs_iext_get_ext(ifp, idx));

  	*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_ino_t	ino,		/* inode number to get data for */
  	void		__user *buffer,	/* not used */
  	int		ubsize,		/* not used */

  	int		*ubused,	/* not used */

  	int		*res)		/* result code value */
  {
  	xfs_inode_t	*ip;

  	xfs_qcnt_t	nblks, rtblks = 0;

  	int		error;
  
  	ASSERT(XFS_IS_QUOTA_RUNNING(mp));
  
  	/*
  	 * rootino must have its resources accounted for, not so with the quota
  	 * inodes.
  	 */

  	if (xfs_is_quota_inode(&mp->m_sb, ino)) {

  		*res = BULKSTAT_RV_NOTHING;

  		return -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.
  	 */

  	error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_EXCL, &ip);
  	if (error) {

  		*res = BULKSTAT_RV_NOTHING;

  		return error;

  	}

  	ASSERT(ip->i_delayed_blks == 0);

  	if (XFS_IS_REALTIME_INODE(ip)) {

  		/*
  		 * Walk thru the extent list and count the realtime blocks.
  		 */

  		error = xfs_qm_get_rtblks(ip, &rtblks);
  		if (error)
  			goto error0;

  	}

  	nblks = (xfs_qcnt_t)ip->i_d.di_nblocks - rtblks;

  
  	/*
  	 * 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 racy, but quotachecks

  	 * and quotaoffs don't race. (Quotachecks happen at mount time only).
  	 */
  	if (XFS_IS_UQUOTA_ON(mp)) {

  		error = xfs_qm_quotacheck_dqadjust(ip, ip->i_d.di_uid,
  						   XFS_DQ_USER, nblks, rtblks);
  		if (error)
  			goto error0;

  	}

  
  	if (XFS_IS_GQUOTA_ON(mp)) {
  		error = xfs_qm_quotacheck_dqadjust(ip, ip->i_d.di_gid,
  						   XFS_DQ_GROUP, nblks, rtblks);
  		if (error)
  			goto error0;

  	}

  	if (XFS_IS_PQUOTA_ON(mp)) {

  		error = xfs_qm_quotacheck_dqadjust(ip, xfs_get_projid(ip),

  						   XFS_DQ_PROJ, nblks, rtblks);
  		if (error)
  			goto error0;
  	}
  
  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
  	IRELE(ip);

  	*res = BULKSTAT_RV_DIDONE;

  	return 0;

  
  error0:
  	xfs_iunlock(ip, XFS_ILOCK_EXCL);
  	IRELE(ip);
  	*res = BULKSTAT_RV_GIVEUP;
  	return error;

  }

  STATIC int
  xfs_qm_flush_one(

  	struct xfs_dquot	*dqp,
  	void			*data)

  {

  	struct list_head	*buffer_list = data;

  	struct xfs_buf		*bp = NULL;

  	int			error = 0;
  
  	xfs_dqlock(dqp);
  	if (dqp->dq_flags & XFS_DQ_FREEING)
  		goto out_unlock;
  	if (!XFS_DQ_IS_DIRTY(dqp))
  		goto out_unlock;

  	xfs_dqflock(dqp);

  	error = xfs_qm_dqflush(dqp, &bp);
  	if (error)
  		goto out_unlock;

  	xfs_buf_delwri_queue(bp, buffer_list);

  	xfs_buf_relse(bp);

  out_unlock:
  	xfs_dqunlock(dqp);
  	return error;
  }

  /*
   * Walk thru all the filesystem inodes and construct a consistent view
   * of the disk quota world. If the quotacheck fails, disable quotas.
   */

  STATIC int

  xfs_qm_quotacheck(
  	xfs_mount_t	*mp)
  {

  	int			done, count, error, error2;
  	xfs_ino_t		lastino;
  	size_t			structsz;
  	uint			flags;
  	LIST_HEAD		(buffer_list);
  	struct xfs_inode	*uip = mp->m_quotainfo->qi_uquotaip;
  	struct xfs_inode	*gip = mp->m_quotainfo->qi_gquotaip;

  	struct xfs_inode	*pip = mp->m_quotainfo->qi_pquotaip;

  
  	count = INT_MAX;
  	structsz = 1;
  	lastino = 0;
  	flags = 0;

  	ASSERT(uip || gip || pip);

  	ASSERT(XFS_IS_QUOTA_RUNNING(mp));

  	xfs_notice(mp, "Quotacheck needed: Please wait.");

  
  	/*

  	 * First we go thru all the dquots on disk, USR and GRP/PRJ, and reset

  	 * their counters to zero. We need a clean slate.
  	 * We don't log our changes till later.
  	 */

  	if (uip) {

  		error = xfs_qm_dqiterate(mp, uip, XFS_QMOPT_UQUOTA,
  					 &buffer_list);

  		if (error)

  			goto error_return;
  		flags |= XFS_UQUOTA_CHKD;
  	}

  	if (gip) {

  		error = xfs_qm_dqiterate(mp, gip, XFS_QMOPT_GQUOTA,

  					 &buffer_list);

  		if (error)

  			goto error_return;

  		flags |= XFS_GQUOTA_CHKD;
  	}
  
  	if (pip) {
  		error = xfs_qm_dqiterate(mp, pip, XFS_QMOPT_PQUOTA,
  					 &buffer_list);
  		if (error)
  			goto error_return;
  		flags |= XFS_PQUOTA_CHKD;

  	}
  
  	do {
  		/*
  		 * Iterate thru all the inodes in the file system,
  		 * adjusting the corresponding dquot counters in core.
  		 */

  		error = xfs_bulkstat(mp, &lastino, &count,
  				     xfs_qm_dqusage_adjust,
  				     structsz, NULL, &done);
  		if (error)

  			break;

  	} while (!done);

  
  	/*

  	 * We've made all the changes that we need to make incore.  Flush them
  	 * down to disk buffers if everything was updated successfully.

  	 */

  	if (XFS_IS_UQUOTA_ON(mp)) {
  		error = xfs_qm_dquot_walk(mp, XFS_DQ_USER, xfs_qm_flush_one,
  					  &buffer_list);
  	}

  	if (XFS_IS_GQUOTA_ON(mp)) {

  		error2 = xfs_qm_dquot_walk(mp, XFS_DQ_GROUP, xfs_qm_flush_one,
  					   &buffer_list);

  		if (!error)
  			error = error2;
  	}
  	if (XFS_IS_PQUOTA_ON(mp)) {

  		error2 = xfs_qm_dquot_walk(mp, XFS_DQ_PROJ, xfs_qm_flush_one,
  					   &buffer_list);

  		if (!error)
  			error = error2;
  	}

  	error2 = xfs_buf_delwri_submit(&buffer_list);
  	if (!error)
  		error = error2;

  	/*

  	 * 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_QUOTALL);

  		goto error_return;
  	}

  
  	/*

  	 * 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_ALL_QUOTA_CHKD;

  	mp->m_qflags |= flags;

   error_return:

  	while (!list_empty(&buffer_list)) {
  		struct xfs_buf *bp =
  			list_first_entry(&buffer_list, struct xfs_buf, b_list);
  		list_del_init(&bp->b_list);
  		xfs_buf_relse(bp);
  	}

  	if (error) {

  		xfs_warn(mp,
  	"Quotacheck: Unsuccessful (Error %d): Disabling quotas.",
  			error);

  		/*
  		 * We must turn off quotas.
  		 */
  		ASSERT(mp->m_quotainfo != NULL);

  		xfs_qm_destroy_quotainfo(mp);

  		if (xfs_mount_reset_sbqflags(mp)) {

  			xfs_warn(mp,
  				"Quotacheck: Failed to reset quota flags.");

  		}

  	} else
  		xfs_notice(mp, "Quotacheck: Done.");

  	return error;

  }
  
  /*

   * 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.
   *
   * If we fail here, the mount will continue with quota turned off. We don't
   * need to inidicate success or failure at all.
   */
  void
  xfs_qm_mount_quotas(
  	struct xfs_mount	*mp)
  {
  	int			error = 0;
  	uint			sbf;
  
  	/*
  	 * If quotas on realtime volumes is not supported, we disable
  	 * quotas immediately.
  	 */
  	if (mp->m_sb.sb_rextents) {
  		xfs_notice(mp, "Cannot turn on quotas for realtime filesystem");
  		mp->m_qflags = 0;
  		goto write_changes;
  	}
  
  	ASSERT(XFS_IS_QUOTA_RUNNING(mp));
  
  	/*
  	 * Allocate the quotainfo structure inside the mount struct, and
  	 * create quotainode(s), and change/rev superblock if necessary.
  	 */
  	error = xfs_qm_init_quotainfo(mp);
  	if (error) {
  		/*
  		 * 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)) {
  		error = xfs_qm_quotacheck(mp);
  		if (error) {
  			/* Quotacheck failed and disabled quotas. */
  			return;
  		}
  	}
  	/*
  	 * 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.
  	 */
  	if (!XFS_IS_UQUOTA_ON(mp))
  		mp->m_qflags &= ~XFS_UQUOTA_CHKD;
  	if (!XFS_IS_GQUOTA_ON(mp))
  		mp->m_qflags &= ~XFS_GQUOTA_CHKD;
  	if (!XFS_IS_PQUOTA_ON(mp))
  		mp->m_qflags &= ~XFS_PQUOTA_CHKD;
  
   write_changes:
  	/*
  	 * We actually don't have to acquire the m_sb_lock at all.
  	 * This can only be called from mount, and that's single threaded. XXX
  	 */
  	spin_lock(&mp->m_sb_lock);
  	sbf = mp->m_sb.sb_qflags;
  	mp->m_sb.sb_qflags = mp->m_qflags & XFS_MOUNT_QUOTA_ALL;
  	spin_unlock(&mp->m_sb_lock);
  
  	if (sbf != (mp->m_qflags & XFS_MOUNT_QUOTA_ALL)) {

  		if (xfs_sync_sb(mp, false)) {

  			/*
  			 * 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_alert(mp, "%s: Superblock update failed!",
  				__func__);
  		}
  	}
  
  	if (error) {
  		xfs_warn(mp, "Failed to initialize disk quotas.");
  		return;
  	}
  }
  
  /*

   * 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)
  {

  	struct xfs_inode	*uip = NULL;
  	struct xfs_inode	*gip = NULL;

  	struct xfs_inode	*pip = NULL;

  	int			error;

  	uint			flags = 0;

  
  	ASSERT(mp->m_quotainfo);

  
  	/*
  	 * 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);

  			error = xfs_iget(mp, NULL, mp->m_sb.sb_uquotino,
  					     0, 0, &uip);
  			if (error)

  				return error;

  		}

  		if (XFS_IS_GQUOTA_ON(mp) &&

  		    mp->m_sb.sb_gquotino != NULLFSINO) {
  			ASSERT(mp->m_sb.sb_gquotino > 0);

  			error = xfs_iget(mp, NULL, mp->m_sb.sb_gquotino,
  					     0, 0, &gip);
  			if (error)
  				goto error_rele;

  		}

  		if (XFS_IS_PQUOTA_ON(mp) &&

  		    mp->m_sb.sb_pquotino != NULLFSINO) {
  			ASSERT(mp->m_sb.sb_pquotino > 0);
  			error = xfs_iget(mp, NULL, mp->m_sb.sb_pquotino,

  					     0, 0, &pip);
  			if (error)
  				goto error_rele;
  		}

  	} else {
  		flags |= XFS_QMOPT_SBVERSION;

  	}
  
  	/*

  	 * Create the three 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) {

  		error = xfs_qm_qino_alloc(mp, &uip,

  					      flags | XFS_QMOPT_UQUOTA);
  		if (error)
  			goto error_rele;

  
  		flags &= ~XFS_QMOPT_SBVERSION;
  	}

  	if (XFS_IS_GQUOTA_ON(mp) && gip == NULL) {

  		error = xfs_qm_qino_alloc(mp, &gip,

  					  flags | XFS_QMOPT_GQUOTA);
  		if (error)
  			goto error_rele;
  
  		flags &= ~XFS_QMOPT_SBVERSION;
  	}
  	if (XFS_IS_PQUOTA_ON(mp) && pip == NULL) {

  		error = xfs_qm_qino_alloc(mp, &pip,

  					  flags | XFS_QMOPT_PQUOTA);

  		if (error)
  			goto error_rele;

  	}

  	mp->m_quotainfo->qi_uquotaip = uip;
  	mp->m_quotainfo->qi_gquotaip = gip;

  	mp->m_quotainfo->qi_pquotaip = pip;

  	return 0;

  
  error_rele:
  	if (uip)
  		IRELE(uip);
  	if (gip)
  		IRELE(gip);

  	if (pip)
  		IRELE(pip);

  	return error;

  }

  STATIC void
  xfs_qm_dqfree_one(
  	struct xfs_dquot	*dqp)
  {
  	struct xfs_mount	*mp = dqp->q_mount;
  	struct xfs_quotainfo	*qi = mp->m_quotainfo;

  	mutex_lock(&qi->qi_tree_lock);

  	radix_tree_delete(xfs_dquot_tree(qi, dqp->q_core.d_flags),

  			  be32_to_cpu(dqp->q_core.d_id));

  	qi->qi_dquots--;

  	mutex_unlock(&qi->qi_tree_lock);

  
  	xfs_qm_dqdestroy(dqp);
  }

  /* --------------- utility functions for vnodeops ---------------- */
  
  
  /*

   * Given an inode, a uid, gid and prid 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(

  	struct xfs_inode	*ip,

  	xfs_dqid_t		uid,
  	xfs_dqid_t		gid,

  	prid_t			prid,
  	uint			flags,
  	struct xfs_dquot	**O_udqpp,

  	struct xfs_dquot	**O_gdqpp,
  	struct xfs_dquot	**O_pdqpp)

  {

  	struct xfs_mount	*mp = ip->i_mount;

  	struct xfs_dquot	*uq = NULL;
  	struct xfs_dquot	*gq = NULL;

  	struct xfs_dquot	*pq = NULL;

  	int			error;
  	uint			lockflags;

  	if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))

  		return 0;
  
  	lockflags = XFS_ILOCK_EXCL;
  	xfs_ilock(ip, lockflags);

  	if ((flags & XFS_QMOPT_INHERIT) && XFS_INHERIT_GID(ip))

  		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)) {

  		error = xfs_qm_dqattach_locked(ip, XFS_QMOPT_DQALLOC);
  		if (error) {

  			xfs_iunlock(ip, lockflags);

  			return error;

  		}
  	}

  	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);

  			error = xfs_qm_dqget(mp, NULL, uid,

  						 XFS_DQ_USER,
  						 XFS_QMOPT_DQALLOC |
  						 XFS_QMOPT_DOWARN,

  						 &uq);
  			if (error) {

  				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 = xfs_qm_dqhold(ip->i_udquot);

  		}
  	}

  	if ((flags & XFS_QMOPT_GQUOTA) && XFS_IS_GQUOTA_ON(mp)) {

  		if (ip->i_d.di_gid != gid) {
  			xfs_iunlock(ip, lockflags);

  			error = xfs_qm_dqget(mp, NULL, gid,

  						 XFS_DQ_GROUP,
  						 XFS_QMOPT_DQALLOC |
  						 XFS_QMOPT_DOWARN,

  						 &gq);
  			if (error) {

  				ASSERT(error != -ENOENT);

  				goto error_rele;

  			}
  			xfs_dqunlock(gq);
  			lockflags = XFS_ILOCK_SHARED;
  			xfs_ilock(ip, lockflags);
  		} else {
  			ASSERT(ip->i_gdquot);

  			gq = xfs_qm_dqhold(ip->i_gdquot);

  		}

  	}
  	if ((flags & XFS_QMOPT_PQUOTA) && XFS_IS_PQUOTA_ON(mp)) {

  		if (xfs_get_projid(ip) != prid) {

  			xfs_iunlock(ip, lockflags);

  			error = xfs_qm_dqget(mp, NULL, (xfs_dqid_t)prid,

  						 XFS_DQ_PROJ,
  						 XFS_QMOPT_DQALLOC |
  						 XFS_QMOPT_DOWARN,

  						 &pq);

  			if (error) {

  				ASSERT(error != -ENOENT);

  				goto error_rele;

  			}

  			xfs_dqunlock(pq);

  			lockflags = XFS_ILOCK_SHARED;
  			xfs_ilock(ip, lockflags);
  		} else {

  			ASSERT(ip->i_pdquot);
  			pq = xfs_qm_dqhold(ip->i_pdquot);

  		}

  	}
  	if (uq)

  		trace_xfs_dquot_dqalloc(ip);

  
  	xfs_iunlock(ip, lockflags);
  	if (O_udqpp)
  		*O_udqpp = uq;

  	else

  		xfs_qm_dqrele(uq);
  	if (O_gdqpp)
  		*O_gdqpp = gq;

  	else

  		xfs_qm_dqrele(gq);

  	if (O_pdqpp)
  		*O_pdqpp = pq;

  	else

  		xfs_qm_dqrele(pq);

  	return 0;

  
  error_rele:

  	xfs_qm_dqrele(gq);
  	xfs_qm_dqrele(uq);

  	return error;

  }
  
  /*
   * 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;

  	uint		bfield = XFS_IS_REALTIME_INODE(ip) ?
  				 XFS_TRANS_DQ_RTBCOUNT : XFS_TRANS_DQ_BCOUNT;

  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));

  	ASSERT(XFS_IS_QUOTA_RUNNING(ip->i_mount));
  
  	/* old dquot */
  	prevdq = *IO_olddq;
  	ASSERT(prevdq);
  	ASSERT(prevdq != newdq);

  	xfs_trans_mod_dquot(tp, prevdq, bfield, -(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, bfield, 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.

  	 */

  	*IO_olddq = xfs_qm_dqhold(newdq);

  	return prevdq;

  }
  
  /*

   * Quota reservations for setattr(AT_UID|AT_GID|AT_PROJID).

   */
  int
  xfs_qm_vop_chown_reserve(

  	struct xfs_trans	*tp,
  	struct xfs_inode	*ip,
  	struct xfs_dquot	*udqp,
  	struct xfs_dquot	*gdqp,

  	struct xfs_dquot	*pdqp,

  	uint			flags)

  {

  	struct xfs_mount	*mp = ip->i_mount;
  	uint			delblks, blkflags, prjflags = 0;
  	struct xfs_dquot	*udq_unres = NULL;
  	struct xfs_dquot	*gdq_unres = NULL;

  	struct xfs_dquot	*pdq_unres = NULL;