text: /*
   * Copyright (c) 2000-2003,2005 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_types.h"
  #include "xfs_bit.h"
  #include "xfs_log.h"
  #include "xfs_inum.h"
  #include "xfs_trans.h"
  #include "xfs_sb.h"
  #include "xfs_ag.h"
  #include "xfs_dir2.h"
  #include "xfs_dmapi.h"
  #include "xfs_mount.h"
  #include "xfs_error.h"
  #include "xfs_da_btree.h"
  #include "xfs_bmap_btree.h"
  #include "xfs_alloc_btree.h"
  #include "xfs_ialloc_btree.h"
  #include "xfs_dir2_sf.h"
  #include "xfs_attr_sf.h"
  #include "xfs_dinode.h"
  #include "xfs_inode.h"
  #include "xfs_btree.h"
  #include "xfs_ialloc.h"
  #include "xfs_alloc.h"
  #include "xfs_bmap.h"
  #include "xfs_quota.h"
  #include "xfs_trans_priv.h"
  #include "xfs_trans_space.h"
  #include "xfs_inode_item.h"
  
  
  STATIC void	xfs_trans_apply_sb_deltas(xfs_trans_t *);
  STATIC uint	xfs_trans_count_vecs(xfs_trans_t *);
  STATIC void	xfs_trans_fill_vecs(xfs_trans_t *, xfs_log_iovec_t *);
  STATIC void	xfs_trans_uncommit(xfs_trans_t *, uint);
  STATIC void	xfs_trans_committed(xfs_trans_t *, int);
  STATIC void	xfs_trans_chunk_committed(xfs_log_item_chunk_t *, xfs_lsn_t, int);
  STATIC void	xfs_trans_free(xfs_trans_t *);
  
  kmem_zone_t	*xfs_trans_zone;
  
  
  /*
   * Reservation functions here avoid a huge stack in xfs_trans_init
   * due to register overflow from temporaries in the calculations.
   */
  
  STATIC uint
  xfs_calc_write_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_WRITE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_itruncate_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_ITRUNCATE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_rename_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_RENAME_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_link_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_LINK_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_remove_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_REMOVE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_symlink_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_SYMLINK_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_create_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_CREATE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_mkdir_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_MKDIR_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_ifree_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_IFREE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_ichange_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_ICHANGE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_growdata_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_GROWDATA_LOG_RES(mp);
  }
  
  STATIC uint
  xfs_calc_growrtalloc_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_GROWRTALLOC_LOG_RES(mp);
  }
  
  STATIC uint
  xfs_calc_growrtzero_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_GROWRTZERO_LOG_RES(mp);
  }
  
  STATIC uint
  xfs_calc_growrtfree_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_GROWRTFREE_LOG_RES(mp);
  }
  
  STATIC uint
  xfs_calc_swrite_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_SWRITE_LOG_RES(mp);
  }
  
  STATIC uint
  xfs_calc_writeid_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_WRITEID_LOG_RES(mp);
  }
  
  STATIC uint
  xfs_calc_addafork_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_ADDAFORK_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_attrinval_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_ATTRINVAL_LOG_RES(mp);
  }
  
  STATIC uint
  xfs_calc_attrset_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_ATTRSET_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_attrrm_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_ATTRRM_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
  }
  
  STATIC uint
  xfs_calc_clear_agi_bucket_reservation(xfs_mount_t *mp)
  {
  	return XFS_CALC_CLEAR_AGI_BUCKET_LOG_RES(mp);
  }
  
  /*
   * Initialize the precomputed transaction reservation values
   * in the mount structure.
   */
  void
  xfs_trans_init(
  	xfs_mount_t	*mp)
  {
  	xfs_trans_reservations_t	*resp;
  
  	resp = &(mp->m_reservations);
  	resp->tr_write = xfs_calc_write_reservation(mp);
  	resp->tr_itruncate = xfs_calc_itruncate_reservation(mp);
  	resp->tr_rename = xfs_calc_rename_reservation(mp);
  	resp->tr_link = xfs_calc_link_reservation(mp);
  	resp->tr_remove = xfs_calc_remove_reservation(mp);
  	resp->tr_symlink = xfs_calc_symlink_reservation(mp);
  	resp->tr_create = xfs_calc_create_reservation(mp);
  	resp->tr_mkdir = xfs_calc_mkdir_reservation(mp);
  	resp->tr_ifree = xfs_calc_ifree_reservation(mp);
  	resp->tr_ichange = xfs_calc_ichange_reservation(mp);
  	resp->tr_growdata = xfs_calc_growdata_reservation(mp);
  	resp->tr_swrite = xfs_calc_swrite_reservation(mp);
  	resp->tr_writeid = xfs_calc_writeid_reservation(mp);
  	resp->tr_addafork = xfs_calc_addafork_reservation(mp);
  	resp->tr_attrinval = xfs_calc_attrinval_reservation(mp);
  	resp->tr_attrset = xfs_calc_attrset_reservation(mp);
  	resp->tr_attrrm = xfs_calc_attrrm_reservation(mp);
  	resp->tr_clearagi = xfs_calc_clear_agi_bucket_reservation(mp);
  	resp->tr_growrtalloc = xfs_calc_growrtalloc_reservation(mp);
  	resp->tr_growrtzero = xfs_calc_growrtzero_reservation(mp);
  	resp->tr_growrtfree = xfs_calc_growrtfree_reservation(mp);
  }
  
  /*
   * This routine is called to allocate a transaction structure.
   * The type parameter indicates the type of the transaction.  These
   * are enumerated in xfs_trans.h.
   *
   * Dynamically allocate the transaction structure from the transaction
   * zone, initialize it, and return it to the caller.
   */
  xfs_trans_t *
  xfs_trans_alloc(
  	xfs_mount_t	*mp,
  	uint		type)
  {
  	xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);
  	return _xfs_trans_alloc(mp, type);
  }
  
  xfs_trans_t *
  _xfs_trans_alloc(
  	xfs_mount_t	*mp,
  	uint		type)
  {
  	xfs_trans_t	*tp;
  
  	atomic_inc(&mp->m_active_trans);
  
  	tp = kmem_zone_zalloc(xfs_trans_zone, KM_SLEEP);
  	tp->t_magic = XFS_TRANS_MAGIC;
  	tp->t_type = type;
  	tp->t_mountp = mp;
  	tp->t_items_free = XFS_LIC_NUM_SLOTS;
  	tp->t_busy_free = XFS_LBC_NUM_SLOTS;
  	xfs_lic_init(&(tp->t_items));
  	XFS_LBC_INIT(&(tp->t_busy));
  	return tp;
  }
  
  /*
   * This is called to create a new transaction which will share the
   * permanent log reservation of the given transaction.  The remaining
   * unused block and rt extent reservations are also inherited.  This
   * implies that the original transaction is no longer allowed to allocate
   * blocks.  Locks and log items, however, are no inherited.  They must
   * be added to the new transaction explicitly.
   */
  xfs_trans_t *
  xfs_trans_dup(
  	xfs_trans_t	*tp)
  {
  	xfs_trans_t	*ntp;
  
  	ntp = kmem_zone_zalloc(xfs_trans_zone, KM_SLEEP);
  
  	/*
  	 * Initialize the new transaction structure.
  	 */
  	ntp->t_magic = XFS_TRANS_MAGIC;
  	ntp->t_type = tp->t_type;
  	ntp->t_mountp = tp->t_mountp;
  	ntp->t_items_free = XFS_LIC_NUM_SLOTS;
  	ntp->t_busy_free = XFS_LBC_NUM_SLOTS;
  	xfs_lic_init(&(ntp->t_items));
  	XFS_LBC_INIT(&(ntp->t_busy));
  
  	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
  	ASSERT(tp->t_ticket != NULL);
  
  	ntp->t_flags = XFS_TRANS_PERM_LOG_RES | (tp->t_flags & XFS_TRANS_RESERVE);
  	ntp->t_ticket = xfs_log_ticket_get(tp->t_ticket);
  	ntp->t_blk_res = tp->t_blk_res - tp->t_blk_res_used;
  	tp->t_blk_res = tp->t_blk_res_used;
  	ntp->t_rtx_res = tp->t_rtx_res - tp->t_rtx_res_used;
  	tp->t_rtx_res = tp->t_rtx_res_used;
  	ntp->t_pflags = tp->t_pflags;
  
  	xfs_trans_dup_dqinfo(tp, ntp);
  
  	atomic_inc(&tp->t_mountp->m_active_trans);
  	return ntp;
  }
  
  /*
   * This is called to reserve free disk blocks and log space for the
   * given transaction.  This must be done before allocating any resources
   * within the transaction.
   *
   * This will return ENOSPC if there are not enough blocks available.
   * It will sleep waiting for available log space.
   * The only valid value for the flags parameter is XFS_RES_LOG_PERM, which
   * is used by long running transactions.  If any one of the reservations
   * fails then they will all be backed out.
   *
   * This does not do quota reservations. That typically is done by the
   * caller afterwards.
   */
  int
  xfs_trans_reserve(
  	xfs_trans_t	*tp,
  	uint		blocks,
  	uint		logspace,
  	uint		rtextents,
  	uint		flags,
  	uint		logcount)
  {
  	int		log_flags;
  	int		error = 0;
  	int		rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
  
  	/* Mark this thread as being in a transaction */
  	current_set_flags_nested(&tp->t_pflags, PF_FSTRANS);
  
  	/*
  	 * Attempt to reserve the needed disk blocks by decrementing
  	 * the number needed from the number available.  This will
  	 * fail if the count would go below zero.
  	 */
  	if (blocks > 0) {
  		error = xfs_mod_incore_sb(tp->t_mountp, XFS_SBS_FDBLOCKS,
  					  -((int64_t)blocks), rsvd);
  		if (error != 0) {
  			current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
  			return (XFS_ERROR(ENOSPC));
  		}
  		tp->t_blk_res += blocks;
  	}
  
  	/*
  	 * Reserve the log space needed for this transaction.
  	 */
  	if (logspace > 0) {
  		ASSERT((tp->t_log_res == 0) || (tp->t_log_res == logspace));
  		ASSERT((tp->t_log_count == 0) ||
  			(tp->t_log_count == logcount));
  		if (flags & XFS_TRANS_PERM_LOG_RES) {
  			log_flags = XFS_LOG_PERM_RESERV;
  			tp->t_flags |= XFS_TRANS_PERM_LOG_RES;
  		} else {
  			ASSERT(tp->t_ticket == NULL);
  			ASSERT(!(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
  			log_flags = 0;
  		}
  
  		error = xfs_log_reserve(tp->t_mountp, logspace, logcount,
  					&tp->t_ticket,
  					XFS_TRANSACTION, log_flags, tp->t_type);
  		if (error) {
  			goto undo_blocks;
  		}
  		tp->t_log_res = logspace;
  		tp->t_log_count = logcount;
  	}
  
  	/*
  	 * Attempt to reserve the needed realtime extents by decrementing
  	 * the number needed from the number available.  This will
  	 * fail if the count would go below zero.
  	 */
  	if (rtextents > 0) {
  		error = xfs_mod_incore_sb(tp->t_mountp, XFS_SBS_FREXTENTS,
  					  -((int64_t)rtextents), rsvd);
  		if (error) {
  			error = XFS_ERROR(ENOSPC);
  			goto undo_log;
  		}
  		tp->t_rtx_res += rtextents;
  	}
  
  	return 0;
  
  	/*
  	 * Error cases jump to one of these labels to undo any
  	 * reservations which have already been performed.
  	 */
  undo_log:
  	if (logspace > 0) {
  		if (flags & XFS_TRANS_PERM_LOG_RES) {
  			log_flags = XFS_LOG_REL_PERM_RESERV;
  		} else {
  			log_flags = 0;
  		}
  		xfs_log_done(tp->t_mountp, tp->t_ticket, NULL, log_flags);
  		tp->t_ticket = NULL;
  		tp->t_log_res = 0;
  		tp->t_flags &= ~XFS_TRANS_PERM_LOG_RES;
  	}
  
  undo_blocks:
  	if (blocks > 0) {
  		(void) xfs_mod_incore_sb(tp->t_mountp, XFS_SBS_FDBLOCKS,
  					 (int64_t)blocks, rsvd);
  		tp->t_blk_res = 0;
  	}
  
  	current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
  
  	return error;
  }
  
  
  /*
   * Record the indicated change to the given field for application
   * to the file system's superblock when the transaction commits.
   * For now, just store the change in the transaction structure.
   *
   * Mark the transaction structure to indicate that the superblock
   * needs to be updated before committing.
   *
   * Because we may not be keeping track of allocated/free inodes and
   * used filesystem blocks in the superblock, we do not mark the
   * superblock dirty in this transaction if we modify these fields.
   * We still need to update the transaction deltas so that they get
   * applied to the incore superblock, but we don't want them to
   * cause the superblock to get locked and logged if these are the
   * only fields in the superblock that the transaction modifies.
   */
  void
  xfs_trans_mod_sb(
  	xfs_trans_t	*tp,
  	uint		field,
  	int64_t		delta)
  {
  	uint32_t	flags = (XFS_TRANS_DIRTY|XFS_TRANS_SB_DIRTY);
  	xfs_mount_t	*mp = tp->t_mountp;
  
  	switch (field) {
  	case XFS_TRANS_SB_ICOUNT:
  		tp->t_icount_delta += delta;
  		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
  			flags &= ~XFS_TRANS_SB_DIRTY;
  		break;
  	case XFS_TRANS_SB_IFREE:
  		tp->t_ifree_delta += delta;
  		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
  			flags &= ~XFS_TRANS_SB_DIRTY;
  		break;
  	case XFS_TRANS_SB_FDBLOCKS:
  		/*
  		 * Track the number of blocks allocated in the
  		 * transaction.  Make sure it does not exceed the
  		 * number reserved.
  		 */
  		if (delta < 0) {
  			tp->t_blk_res_used += (uint)-delta;
  			ASSERT(tp->t_blk_res_used <= tp->t_blk_res);
  		}
  		tp->t_fdblocks_delta += delta;
  		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
  			flags &= ~XFS_TRANS_SB_DIRTY;
  		break;
  	case XFS_TRANS_SB_RES_FDBLOCKS:
  		/*
  		 * The allocation has already been applied to the
  		 * in-core superblock's counter.  This should only
  		 * be applied to the on-disk superblock.
  		 */
  		ASSERT(delta < 0);
  		tp->t_res_fdblocks_delta += delta;
  		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
  			flags &= ~XFS_TRANS_SB_DIRTY;
  		break;
  	case XFS_TRANS_SB_FREXTENTS:
  		/*
  		 * Track the number of blocks allocated in the
  		 * transaction.  Make sure it does not exceed the
  		 * number reserved.
  		 */
  		if (delta < 0) {
  			tp->t_rtx_res_used += (uint)-delta;
  			ASSERT(tp->t_rtx_res_used <= tp->t_rtx_res);
  		}
  		tp->t_frextents_delta += delta;
  		break;
  	case XFS_TRANS_SB_RES_FREXTENTS:
  		/*
  		 * The allocation has already been applied to the
  		 * in-core superblock's counter.  This should only
  		 * be applied to the on-disk superblock.
  		 */
  		ASSERT(delta < 0);
  		tp->t_res_frextents_delta += delta;
  		break;
  	case XFS_TRANS_SB_DBLOCKS:
  		ASSERT(delta > 0);
  		tp->t_dblocks_delta += delta;
  		break;
  	case XFS_TRANS_SB_AGCOUNT:
  		ASSERT(delta > 0);
  		tp->t_agcount_delta += delta;
  		break;
  	case XFS_TRANS_SB_IMAXPCT:
  		tp->t_imaxpct_delta += delta;
  		break;
  	case XFS_TRANS_SB_REXTSIZE:
  		tp->t_rextsize_delta += delta;
  		break;
  	case XFS_TRANS_SB_RBMBLOCKS:
  		tp->t_rbmblocks_delta += delta;
  		break;
  	case XFS_TRANS_SB_RBLOCKS:
  		tp->t_rblocks_delta += delta;
  		break;
  	case XFS_TRANS_SB_REXTENTS:
  		tp->t_rextents_delta += delta;
  		break;
  	case XFS_TRANS_SB_REXTSLOG:
  		tp->t_rextslog_delta += delta;
  		break;
  	default:
  		ASSERT(0);
  		return;
  	}
  
  	tp->t_flags |= flags;
  }
  
  /*
   * xfs_trans_apply_sb_deltas() is called from the commit code
   * to bring the superblock buffer into the current transaction
   * and modify it as requested by earlier calls to xfs_trans_mod_sb().
   *
   * For now we just look at each field allowed to change and change
   * it if necessary.
   */
  STATIC void
  xfs_trans_apply_sb_deltas(
  	xfs_trans_t	*tp)
  {
  	xfs_dsb_t	*sbp;
  	xfs_buf_t	*bp;
  	int		whole = 0;
  
  	bp = xfs_trans_getsb(tp, tp->t_mountp, 0);
  	sbp = XFS_BUF_TO_SBP(bp);
  
  	/*
  	 * Check that superblock mods match the mods made to AGF counters.
  	 */
  	ASSERT((tp->t_fdblocks_delta + tp->t_res_fdblocks_delta) ==
  	       (tp->t_ag_freeblks_delta + tp->t_ag_flist_delta +
  		tp->t_ag_btree_delta));
  
  	/*
  	 * Only update the superblock counters if we are logging them
  	 */
  	if (!xfs_sb_version_haslazysbcount(&(tp->t_mountp->m_sb))) {
  		if (tp->t_icount_delta)
  			be64_add_cpu(&sbp->sb_icount, tp->t_icount_delta);
  		if (tp->t_ifree_delta)
  			be64_add_cpu(&sbp->sb_ifree, tp->t_ifree_delta);
  		if (tp->t_fdblocks_delta)
  			be64_add_cpu(&sbp->sb_fdblocks, tp->t_fdblocks_delta);
  		if (tp->t_res_fdblocks_delta)
  			be64_add_cpu(&sbp->sb_fdblocks, tp->t_res_fdblocks_delta);
  	}
  
  	if (tp->t_frextents_delta)
  		be64_add_cpu(&sbp->sb_frextents, tp->t_frextents_delta);
  	if (tp->t_res_frextents_delta)
  		be64_add_cpu(&sbp->sb_frextents, tp->t_res_frextents_delta);
  
  	if (tp->t_dblocks_delta) {
  		be64_add_cpu(&sbp->sb_dblocks, tp->t_dblocks_delta);
  		whole = 1;
  	}
  	if (tp->t_agcount_delta) {
  		be32_add_cpu(&sbp->sb_agcount, tp->t_agcount_delta);
  		whole = 1;
  	}
  	if (tp->t_imaxpct_delta) {
  		sbp->sb_imax_pct += tp->t_imaxpct_delta;
  		whole = 1;
  	}
  	if (tp->t_rextsize_delta) {
  		be32_add_cpu(&sbp->sb_rextsize, tp->t_rextsize_delta);
  		whole = 1;
  	}
  	if (tp->t_rbmblocks_delta) {
  		be32_add_cpu(&sbp->sb_rbmblocks, tp->t_rbmblocks_delta);
  		whole = 1;
  	}
  	if (tp->t_rblocks_delta) {
  		be64_add_cpu(&sbp->sb_rblocks, tp->t_rblocks_delta);
  		whole = 1;
  	}
  	if (tp->t_rextents_delta) {
  		be64_add_cpu(&sbp->sb_rextents, tp->t_rextents_delta);
  		whole = 1;
  	}
  	if (tp->t_rextslog_delta) {
  		sbp->sb_rextslog += tp->t_rextslog_delta;
  		whole = 1;
  	}
  
  	if (whole)
  		/*
  		 * Log the whole thing, the fields are noncontiguous.
  		 */
  		xfs_trans_log_buf(tp, bp, 0, sizeof(xfs_dsb_t) - 1);
  	else
  		/*
  		 * Since all the modifiable fields are contiguous, we
  		 * can get away with this.
  		 */
  		xfs_trans_log_buf(tp, bp, offsetof(xfs_dsb_t, sb_icount),
  				  offsetof(xfs_dsb_t, sb_frextents) +
  				  sizeof(sbp->sb_frextents) - 1);
  }
  
  /*
   * xfs_trans_unreserve_and_mod_sb() is called to release unused reservations
   * and apply superblock counter changes to the in-core superblock.  The
   * t_res_fdblocks_delta and t_res_frextents_delta fields are explicitly NOT
   * applied to the in-core superblock.  The idea is that that has already been
   * done.
   *
   * This is done efficiently with a single call to xfs_mod_incore_sb_batch().
   * However, we have to ensure that we only modify each superblock field only
   * once because the application of the delta values may not be atomic. That can
   * lead to ENOSPC races occurring if we have two separate modifcations of the
   * free space counter to put back the entire reservation and then take away
   * what we used.
   *
   * If we are not logging superblock counters, then the inode allocated/free and
   * used block counts are not updated in the on disk superblock. In this case,
   * XFS_TRANS_SB_DIRTY will not be set when the transaction is updated but we
   * still need to update the incore superblock with the changes.
   */
  STATIC void
  xfs_trans_unreserve_and_mod_sb(
  	xfs_trans_t	*tp)
  {
  	xfs_mod_sb_t	msb[14];	/* If you add cases, add entries */
  	xfs_mod_sb_t	*msbp;
  	xfs_mount_t	*mp = tp->t_mountp;
  	/* REFERENCED */
  	int		error;
  	int		rsvd;
  	int64_t		blkdelta = 0;
  	int64_t		rtxdelta = 0;
  
  	msbp = msb;
  	rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
  
  	/* calculate free blocks delta */
  	if (tp->t_blk_res > 0)
  		blkdelta = tp->t_blk_res;
  
  	if ((tp->t_fdblocks_delta != 0) &&
  	    (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
  	     (tp->t_flags & XFS_TRANS_SB_DIRTY)))
  	        blkdelta += tp->t_fdblocks_delta;
  
  	if (blkdelta != 0) {
  		msbp->msb_field = XFS_SBS_FDBLOCKS;
  		msbp->msb_delta = blkdelta;
  		msbp++;
  	}
  
  	/* calculate free realtime extents delta */
  	if (tp->t_rtx_res > 0)
  		rtxdelta = tp->t_rtx_res;
  
  	if ((tp->t_frextents_delta != 0) &&
  	    (tp->t_flags & XFS_TRANS_SB_DIRTY))
  		rtxdelta += tp->t_frextents_delta;
  
  	if (rtxdelta != 0) {
  		msbp->msb_field = XFS_SBS_FREXTENTS;
  		msbp->msb_delta = rtxdelta;
  		msbp++;
  	}
  
  	/* apply remaining deltas */
  
  	if (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
  	     (tp->t_flags & XFS_TRANS_SB_DIRTY)) {
  		if (tp->t_icount_delta != 0) {
  			msbp->msb_field = XFS_SBS_ICOUNT;
  			msbp->msb_delta = tp->t_icount_delta;
  			msbp++;
  		}
  		if (tp->t_ifree_delta != 0) {
  			msbp->msb_field = XFS_SBS_IFREE;
  			msbp->msb_delta = tp->t_ifree_delta;
  			msbp++;
  		}
  	}
  
  	if (tp->t_flags & XFS_TRANS_SB_DIRTY) {
  		if (tp->t_dblocks_delta != 0) {
  			msbp->msb_field = XFS_SBS_DBLOCKS;
  			msbp->msb_delta = tp->t_dblocks_delta;
  			msbp++;
  		}
  		if (tp->t_agcount_delta != 0) {
  			msbp->msb_field = XFS_SBS_AGCOUNT;
  			msbp->msb_delta = tp->t_agcount_delta;
  			msbp++;
  		}
  		if (tp->t_imaxpct_delta != 0) {
  			msbp->msb_field = XFS_SBS_IMAX_PCT;
  			msbp->msb_delta = tp->t_imaxpct_delta;
  			msbp++;
  		}
  		if (tp->t_rextsize_delta != 0) {
  			msbp->msb_field = XFS_SBS_REXTSIZE;
  			msbp->msb_delta = tp->t_rextsize_delta;
  			msbp++;
  		}
  		if (tp->t_rbmblocks_delta != 0) {
  			msbp->msb_field = XFS_SBS_RBMBLOCKS;
  			msbp->msb_delta = tp->t_rbmblocks_delta;
  			msbp++;
  		}
  		if (tp->t_rblocks_delta != 0) {
  			msbp->msb_field = XFS_SBS_RBLOCKS;
  			msbp->msb_delta = tp->t_rblocks_delta;
  			msbp++;
  		}
  		if (tp->t_rextents_delta != 0) {
  			msbp->msb_field = XFS_SBS_REXTENTS;
  			msbp->msb_delta = tp->t_rextents_delta;
  			msbp++;
  		}
  		if (tp->t_rextslog_delta != 0) {
  			msbp->msb_field = XFS_SBS_REXTSLOG;
  			msbp->msb_delta = tp->t_rextslog_delta;
  			msbp++;
  		}
  	}
  
  	/*
  	 * If we need to change anything, do it.
  	 */
  	if (msbp > msb) {
  		error = xfs_mod_incore_sb_batch(tp->t_mountp, msb,
  			(uint)(msbp - msb), rsvd);
  		ASSERT(error == 0);
  	}
  }
  
  
  /*
   * xfs_trans_commit
   *
   * Commit the given transaction to the log a/synchronously.
   *
   * XFS disk error handling mechanism is not based on a typical
   * transaction abort mechanism. Logically after the filesystem
   * gets marked 'SHUTDOWN', we can't let any new transactions
   * be durable - ie. committed to disk - because some metadata might
   * be inconsistent. In such cases, this returns an error, and the
   * caller may assume that all locked objects joined to the transaction
   * have already been unlocked as if the commit had succeeded.
   * Do not reference the transaction structure after this call.
   */
   /*ARGSUSED*/
  int
  _xfs_trans_commit(
  	xfs_trans_t	*tp,
  	uint		flags,
  	int		*log_flushed)
  {
  	xfs_log_iovec_t		*log_vector;
  	int			nvec;
  	xfs_mount_t		*mp;
  	xfs_lsn_t		commit_lsn;
  	/* REFERENCED */
  	int			error;
  	int			log_flags;
  	int			sync;
  #define	XFS_TRANS_LOGVEC_COUNT	16
  	xfs_log_iovec_t		log_vector_fast[XFS_TRANS_LOGVEC_COUNT];
  	void			*commit_iclog;
  	int			shutdown;
  
  	commit_lsn = -1;
  
  	/*
  	 * Determine whether this commit is releasing a permanent
  	 * log reservation or not.
  	 */
  	if (flags & XFS_TRANS_RELEASE_LOG_RES) {
  		ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
  		log_flags = XFS_LOG_REL_PERM_RESERV;
  	} else {
  		log_flags = 0;
  	}
  	mp = tp->t_mountp;
  
  	/*
  	 * If there is nothing to be logged by the transaction,
  	 * then unlock all of the items associated with the
  	 * transaction and free the transaction structure.
  	 * Also make sure to return any reserved blocks to
  	 * the free pool.
  	 */
  shut_us_down:
  	shutdown = XFS_FORCED_SHUTDOWN(mp) ? EIO : 0;
  	if (!(tp->t_flags & XFS_TRANS_DIRTY) || shutdown) {
  		xfs_trans_unreserve_and_mod_sb(tp);
  		/*
  		 * It is indeed possible for the transaction to be
  		 * not dirty but the dqinfo portion to be. All that
  		 * means is that we have some (non-persistent) quota
  		 * reservations that need to be unreserved.
  		 */
  		xfs_trans_unreserve_and_mod_dquots(tp);
  		if (tp->t_ticket) {
  			commit_lsn = xfs_log_done(mp, tp->t_ticket,
  							NULL, log_flags);
  			if (commit_lsn == -1 && !shutdown)
  				shutdown = XFS_ERROR(EIO);
  		}
  		current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
  		xfs_trans_free_items(tp, shutdown? XFS_TRANS_ABORT : 0);
  		xfs_trans_free_busy(tp);
  		xfs_trans_free(tp);
  		XFS_STATS_INC(xs_trans_empty);
  		return (shutdown);
  	}
  	ASSERT(tp->t_ticket != NULL);
  
  	/*
  	 * If we need to update the superblock, then do it now.
  	 */
  	if (tp->t_flags & XFS_TRANS_SB_DIRTY)
  		xfs_trans_apply_sb_deltas(tp);
  	xfs_trans_apply_dquot_deltas(tp);
  
  	/*
  	 * Ask each log item how many log_vector entries it will
  	 * need so we can figure out how many to allocate.
  	 * Try to avoid the kmem_alloc() call in the common case
  	 * by using a vector from the stack when it fits.
  	 */
  	nvec = xfs_trans_count_vecs(tp);
  	if (nvec == 0) {
  		xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
  		goto shut_us_down;
  	} else if (nvec <= XFS_TRANS_LOGVEC_COUNT) {
  		log_vector = log_vector_fast;
  	} else {
  		log_vector = (xfs_log_iovec_t *)kmem_alloc(nvec *
  						   sizeof(xfs_log_iovec_t),
  						   KM_SLEEP);
  	}
  
  	/*
  	 * Fill in the log_vector and pin the logged items, and
  	 * then write the transaction to the log.
  	 */
  	xfs_trans_fill_vecs(tp, log_vector);
  
  	error = xfs_log_write(mp, log_vector, nvec, tp->t_ticket, &(tp->t_lsn));
  
  	/*
  	 * The transaction is committed incore here, and can go out to disk
  	 * at any time after this call.  However, all the items associated
  	 * with the transaction are still locked and pinned in memory.
  	 */
  	commit_lsn = xfs_log_done(mp, tp->t_ticket, &commit_iclog, log_flags);
  
  	tp->t_commit_lsn = commit_lsn;
  	if (nvec > XFS_TRANS_LOGVEC_COUNT) {
  		kmem_free(log_vector);
  	}
  
  	/*
  	 * If we got a log write error. Unpin the logitems that we
  	 * had pinned, clean up, free trans structure, and return error.
  	 */
  	if (error || commit_lsn == -1) {
  		current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
  		xfs_trans_uncommit(tp, flags|XFS_TRANS_ABORT);
  		return XFS_ERROR(EIO);
  	}
  
  	/*
  	 * Once the transaction has committed, unused
  	 * reservations need to be released and changes to
  	 * the superblock need to be reflected in the in-core
  	 * version.  Do that now.
  	 */
  	xfs_trans_unreserve_and_mod_sb(tp);
  
  	sync = tp->t_flags & XFS_TRANS_SYNC;
  
  	/*
  	 * Tell the LM to call the transaction completion routine
  	 * when the log write with LSN commit_lsn completes (e.g.
  	 * when the transaction commit really hits the on-disk log).
  	 * After this call we cannot reference tp, because the call
  	 * can happen at any time and the call will free the transaction
  	 * structure pointed to by tp.  The only case where we call
  	 * the completion routine (xfs_trans_committed) directly is
  	 * if the log is turned off on a debug kernel or we're
  	 * running in simulation mode (the log is explicitly turned
  	 * off).
  	 */
  	tp->t_logcb.cb_func = (void(*)(void*, int))xfs_trans_committed;
  	tp->t_logcb.cb_arg = tp;
  
  	/*
  	 * We need to pass the iclog buffer which was used for the
  	 * transaction commit record into this function, and attach
  	 * the callback to it. The callback must be attached before
  	 * the items are unlocked to avoid racing with other threads
  	 * waiting for an item to unlock.
  	 */
  	shutdown = xfs_log_notify(mp, commit_iclog, &(tp->t_logcb));
  
  	/*
  	 * Mark this thread as no longer being in a transaction
  	 */
  	current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
  
  	/*
  	 * Once all the items of the transaction have been copied
  	 * to the in core log and the callback is attached, the
  	 * items can be unlocked.
  	 *
  	 * This will free descriptors pointing to items which were
  	 * not logged since there is nothing more to do with them.
  	 * For items which were logged, we will keep pointers to them
  	 * so they can be unpinned after the transaction commits to disk.
  	 * This will also stamp each modified meta-data item with
  	 * the commit lsn of this transaction for dependency tracking
  	 * purposes.
  	 */
  	xfs_trans_unlock_items(tp, commit_lsn);
  
  	/*
  	 * If we detected a log error earlier, finish committing
  	 * the transaction now (unpin log items, etc).
  	 *
  	 * Order is critical here, to avoid using the transaction
  	 * pointer after its been freed (by xfs_trans_committed
  	 * either here now, or as a callback).  We cannot do this
  	 * step inside xfs_log_notify as was done earlier because
  	 * of this issue.
  	 */
  	if (shutdown)
  		xfs_trans_committed(tp, XFS_LI_ABORTED);
  
  	/*
  	 * Now that the xfs_trans_committed callback has been attached,
  	 * and the items are released we can finally allow the iclog to
  	 * go to disk.
  	 */
  	error = xfs_log_release_iclog(mp, commit_iclog);
  
  	/*
  	 * If the transaction needs to be synchronous, then force the
  	 * log out now and wait for it.
  	 */
  	if (sync) {
  		if (!error) {
  			error = _xfs_log_force(mp, commit_lsn,
  				      XFS_LOG_FORCE | XFS_LOG_SYNC,
  				      log_flushed);
  		}
  		XFS_STATS_INC(xs_trans_sync);
  	} else {
  		XFS_STATS_INC(xs_trans_async);
  	}
  
  	return (error);
  }
  
  
  /*
   * Total up the number of log iovecs needed to commit this
   * transaction.  The transaction itself needs one for the
   * transaction header.  Ask each dirty item in turn how many
   * it needs to get the total.
   */
  STATIC uint
  xfs_trans_count_vecs(
  	xfs_trans_t	*tp)
  {
  	int			nvecs;
  	xfs_log_item_desc_t	*lidp;
  
  	nvecs = 1;
  	lidp = xfs_trans_first_item(tp);
  	ASSERT(lidp != NULL);
  
  	/* In the non-debug case we need to start bailing out if we
  	 * didn't find a log_item here, return zero and let trans_commit
  	 * deal with it.
  	 */
  	if (lidp == NULL)
  		return 0;
  
  	while (lidp != NULL) {
  		/*
  		 * Skip items which aren't dirty in this transaction.
  		 */
  		if (!(lidp->lid_flags & XFS_LID_DIRTY)) {
  			lidp = xfs_trans_next_item(tp, lidp);
  			continue;
  		}
  		lidp->lid_size = IOP_SIZE(lidp->lid_item);
  		nvecs += lidp->lid_size;
  		lidp = xfs_trans_next_item(tp, lidp);
  	}
  
  	return nvecs;
  }
  
  /*
   * Called from the trans_commit code when we notice that
   * the filesystem is in the middle of a forced shutdown.
   */
  STATIC void
  xfs_trans_uncommit(
  	xfs_trans_t	*tp,
  	uint		flags)
  {
  	xfs_log_item_desc_t	*lidp;
  
  	for (lidp = xfs_trans_first_item(tp);
  	     lidp != NULL;
  	     lidp = xfs_trans_next_item(tp, lidp)) {
  		/*
  		 * Unpin all but those that aren't dirty.
  		 */
  		if (lidp->lid_flags & XFS_LID_DIRTY)
  			IOP_UNPIN_REMOVE(lidp->lid_item, tp);
  	}
  
  	xfs_trans_unreserve_and_mod_sb(tp);
  	xfs_trans_unreserve_and_mod_dquots(tp);
  
  	xfs_trans_free_items(tp, flags);
  	xfs_trans_free_busy(tp);
  	xfs_trans_free(tp);
  }
  
  /*
   * Fill in the vector with pointers to data to be logged
   * by this transaction.  The transaction header takes
   * the first vector, and then each dirty item takes the
   * number of vectors it indicated it needed in xfs_trans_count_vecs().
   *
   * As each item fills in the entries it needs, also pin the item
   * so that it cannot be flushed out until the log write completes.
   */
  STATIC void
  xfs_trans_fill_vecs(
  	xfs_trans_t		*tp,
  	xfs_log_iovec_t		*log_vector)
  {
  	xfs_log_item_desc_t	*lidp;
  	xfs_log_iovec_t		*vecp;
  	uint			nitems;
  
  	/*
  	 * Skip over the entry for the transaction header, we'll
  	 * fill that in at the end.
  	 */
  	vecp = log_vector + 1;		/* pointer arithmetic */
  
  	nitems = 0;
  	lidp = xfs_trans_first_item(tp);
  	ASSERT(lidp != NULL);
  	while (lidp != NULL) {
  		/*
  		 * Skip items which aren't dirty in this transaction.
  		 */
  		if (!(lidp->lid_flags & XFS_LID_DIRTY)) {
  			lidp = xfs_trans_next_item(tp, lidp);
  			continue;
  		}
  		/*
  		 * The item may be marked dirty but not log anything.
  		 * This can be used to get called when a transaction
  		 * is committed.
  		 */
  		if (lidp->lid_size) {
  			nitems++;
  		}
  		IOP_FORMAT(lidp->lid_item, vecp);
  		vecp += lidp->lid_size;		/* pointer arithmetic */
  		IOP_PIN(lidp->lid_item);
  		lidp = xfs_trans_next_item(tp, lidp);
  	}
  
  	/*
  	 * Now that we've counted the number of items in this
  	 * transaction, fill in the transaction header.
  	 */
  	tp->t_header.th_magic = XFS_TRANS_HEADER_MAGIC;
  	tp->t_header.th_type = tp->t_type;
  	tp->t_header.th_num_items = nitems;
  	log_vector->i_addr = (xfs_caddr_t)&tp->t_header;
  	log_vector->i_len = sizeof(xfs_trans_header_t);
  	XLOG_VEC_SET_TYPE(log_vector, XLOG_REG_TYPE_TRANSHDR);
  }
  
  
  /*
   * Unlock all of the transaction's items and free the transaction.
   * The transaction must not have modified any of its items, because
   * there is no way to restore them to their previous state.
   *
   * If the transaction has made a log reservation, make sure to release
   * it as well.
   */
  void
  xfs_trans_cancel(
  	xfs_trans_t		*tp,
  	int			flags)
  {
  	int			log_flags;
  #ifdef DEBUG
  	xfs_log_item_chunk_t	*licp;
  	xfs_log_item_desc_t	*lidp;
  	xfs_log_item_t		*lip;
  	int			i;
  #endif
  	xfs_mount_t		*mp = tp->t_mountp;
  
  	/*
  	 * See if the caller is being too lazy to figure out if
  	 * the transaction really needs an abort.
  	 */
  	if ((flags & XFS_TRANS_ABORT) && !(tp->t_flags & XFS_TRANS_DIRTY))
  		flags &= ~XFS_TRANS_ABORT;
  	/*
  	 * See if the caller is relying on us to shut down the
  	 * filesystem.  This happens in paths where we detect
  	 * corruption and decide to give up.
  	 */
  	if ((tp->t_flags & XFS_TRANS_DIRTY) && !XFS_FORCED_SHUTDOWN(mp)) {
  		XFS_ERROR_REPORT("xfs_trans_cancel", XFS_ERRLEVEL_LOW, mp);
  		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
  	}
  #ifdef DEBUG
  	if (!(flags & XFS_TRANS_ABORT)) {
  		licp = &(tp->t_items);
  		while (licp != NULL) {
  			lidp = licp->lic_descs;
  			for (i = 0; i < licp->lic_unused; i++, lidp++) {
  				if (xfs_lic_isfree(licp, i)) {
  					continue;
  				}
  
  				lip = lidp->lid_item;
  				if (!XFS_FORCED_SHUTDOWN(mp))
  					ASSERT(!(lip->li_type == XFS_LI_EFD));
  			}
  			licp = licp->lic_next;
  		}
  	}
  #endif
  	xfs_trans_unreserve_and_mod_sb(tp);
  	xfs_trans_unreserve_and_mod_dquots(tp);
  
  	if (tp->t_ticket) {
  		if (flags & XFS_TRANS_RELEASE_LOG_RES) {
  			ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
  			log_flags = XFS_LOG_REL_PERM_RESERV;
  		} else {
  			log_flags = 0;
  		}
  		xfs_log_done(mp, tp->t_ticket, NULL, log_flags);
  	}
  
  	/* mark this thread as no longer being in a transaction */
  	current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
  
  	xfs_trans_free_items(tp, flags);
  	xfs_trans_free_busy(tp);
  	xfs_trans_free(tp);
  }
  
  
  /*
   * Free the transaction structure.  If there is more clean up
   * to do when the structure is freed, add it here.
   */
  STATIC void
  xfs_trans_free(
  	xfs_trans_t	*tp)
  {
  	atomic_dec(&tp->t_mountp->m_active_trans);
  	xfs_trans_free_dqinfo(tp);
  	kmem_zone_free(xfs_trans_zone, tp);
  }
  
  /*
   * Roll from one trans in the sequence of PERMANENT transactions to
   * the next: permanent transactions are only flushed out when
   * committed with XFS_TRANS_RELEASE_LOG_RES, but we still want as soon
   * as possible to let chunks of it go to the log. So we commit the
   * chunk we've been working on and get a new transaction to continue.
   */
  int
  xfs_trans_roll(
  	struct xfs_trans	**tpp,
  	struct xfs_inode	*dp)
  {
  	struct xfs_trans	*trans;
  	unsigned int		logres, count;
  	int			error;
  
  	/*
  	 * Ensure that the inode is always logged.
  	 */
  	trans = *tpp;
  	xfs_trans_log_inode(trans, dp, XFS_ILOG_CORE);
  
  	/*
  	 * Copy the critical parameters from one trans to the next.
  	 */
  	logres = trans->t_log_res;
  	count = trans->t_log_count;
  	*tpp = xfs_trans_dup(trans);
  
  	/*
  	 * Commit the current transaction.
  	 * If this commit failed, then it'd just unlock those items that
  	 * are not marked ihold. That also means that a filesystem shutdown
  	 * is in progress. The caller takes the responsibility to cancel
  	 * the duplicate transaction that gets returned.
  	 */
  	error = xfs_trans_commit(trans, 0);
  	if (error)
  		return (error);
  
  	trans = *tpp;
  
  	/*
  	 * transaction commit worked ok so we can drop the extra ticket
  	 * reference that we gained in xfs_trans_dup()
  	 */
  	xfs_log_ticket_put(trans->t_ticket);
  
  
  	/*
  	 * Reserve space in the log for th next transaction.
  	 * This also pushes items in the "AIL", the list of logged items,
  	 * out to disk if they are taking up space at the tail of the log
  	 * that we want to use.  This requires that either nothing be locked
  	 * across this call, or that anything that is locked be logged in
  	 * the prior and the next transactions.
  	 */
  	error = xfs_trans_reserve(trans, 0, logres, 0,
  				  XFS_TRANS_PERM_LOG_RES, count);
  	/*
  	 *  Ensure that the inode is in the new transaction and locked.
  	 */
  	if (error)
  		return error;
  
  	xfs_trans_ijoin(trans, dp, XFS_ILOCK_EXCL);
  	xfs_trans_ihold(trans, dp);
  	return 0;
  }
  
  /*
   * THIS SHOULD BE REWRITTEN TO USE xfs_trans_next_item().
   *
   * This is typically called by the LM when a transaction has been fully
   * committed to disk.  It needs to unpin the items which have
   * been logged by the transaction and update their positions
   * in the AIL if necessary.
   * This also gets called when the transactions didn't get written out
   * because of an I/O error. Abortflag & XFS_LI_ABORTED is set then.
   *
   * Call xfs_trans_chunk_committed() to process the items in
   * each chunk.
   */
  STATIC void
  xfs_trans_committed(
  	xfs_trans_t	*tp,
  	int		abortflag)
  {
  	xfs_log_item_chunk_t	*licp;
  	xfs_log_item_chunk_t	*next_licp;
  	xfs_log_busy_chunk_t	*lbcp;
  	xfs_log_busy_slot_t	*lbsp;
  	int			i;
  
  	/*
  	 * Call the transaction's completion callback if there
  	 * is one.
  	 */
  	if (tp->t_callback != NULL) {
  		tp->t_callback(tp, tp->t_callarg);
  	}
  
  	/*
  	 * Special case the chunk embedded in the transaction.
  	 */
  	licp = &(tp->t_items);
  	if (!(xfs_lic_are_all_free(licp))) {
  		xfs_trans_chunk_committed(licp, tp->t_lsn, abortflag);
  	}
  
  	/*
  	 * Process the items in each chunk in turn.
  	 */
  	licp = licp->lic_next;
  	while (licp != NULL) {
  		ASSERT(!xfs_lic_are_all_free(licp));
  		xfs_trans_chunk_committed(licp, tp->t_lsn, abortflag);
  		next_licp = licp->lic_next;
  		kmem_free(licp);
  		licp = next_licp;
  	}
  
  	/*
  	 * Clear all the per-AG busy list items listed in this transaction
  	 */
  	lbcp = &tp->t_busy;
  	while (lbcp != NULL) {
  		for (i = 0, lbsp = lbcp->lbc_busy; i < lbcp->lbc_unused; i++, lbsp++) {
  			if (!XFS_LBC_ISFREE(lbcp, i)) {
  				xfs_alloc_clear_busy(tp, lbsp->lbc_ag,
  						     lbsp->lbc_idx);
  			}
  		}
  		lbcp = lbcp->lbc_next;
  	}
  	xfs_trans_free_busy(tp);
  
  	/*
  	 * That's it for the transaction structure.  Free it.
  	 */
  	xfs_trans_free(tp);
  }
  
  /*
   * This is called to perform the commit processing for each
   * item described by the given chunk.
   *
   * The commit processing consists of unlocking items which were
   * held locked with the SYNC_UNLOCK attribute, calling the committed
   * routine of each logged item, updating the item's position in the AIL
   * if necessary, and unpinning each item.  If the committed routine
   * returns -1, then do nothing further with the item because it
   * may have been freed.
   *
   * Since items are unlocked when they are copied to the incore
   * log, it is possible for two transactions to be completing
   * and manipulating the same item simultaneously.  The AIL lock
   * will protect the lsn field of each item.  The value of this
   * field can never go backwards.
   *
   * We unpin the items after repositioning them in the AIL, because
   * otherwise they could be immediately flushed and we'd have to race
   * with the flusher trying to pull the item from the AIL as we add it.
   */
  STATIC void
  xfs_trans_chunk_committed(
  	xfs_log_item_chunk_t	*licp,
  	xfs_lsn_t		lsn,
  	int			aborted)
  {
  	xfs_log_item_desc_t	*lidp;
  	xfs_log_item_t		*lip;
  	xfs_lsn_t		item_lsn;
  	int			i;
  
  	lidp = licp->lic_descs;
  	for (i = 0; i < licp->lic_unused; i++, lidp++) {
  		struct xfs_ail		*ailp;
  
  		if (xfs_lic_isfree(licp, i)) {
  			continue;
  		}
  
  		lip = lidp->lid_item;
  		if (aborted)
  			lip->li_flags |= XFS_LI_ABORTED;
  
  		/*
  		 * Send in the ABORTED flag to the COMMITTED routine
  		 * so that it knows whether the transaction was aborted
  		 * or not.
  		 */
  		item_lsn = IOP_COMMITTED(lip, lsn);
  
  		/*
  		 * If the committed routine returns -1, make
  		 * no more references to the item.
  		 */
  		if (XFS_LSN_CMP(item_lsn, (xfs_lsn_t)-1) == 0) {
  			continue;
  		}
  
  		/*
  		 * If the returned lsn is greater than what it
  		 * contained before, update the location of the
  		 * item in the AIL.  If it is not, then do nothing.
  		 * Items can never move backwards in the AIL.
  		 *
  		 * While the new lsn should usually be greater, it
  		 * is possible that a later transaction completing
  		 * simultaneously with an earlier one using the
  		 * same item could complete first with a higher lsn.
  		 * This would cause the earlier transaction to fail
  		 * the test below.
  		 */
  		ailp = lip->li_ailp;
  		spin_lock(&ailp->xa_lock);
  		if (XFS_LSN_CMP(item_lsn, lip->li_lsn) > 0) {
  			/*
  			 * This will set the item's lsn to item_lsn
  			 * and update the position of the item in
  			 * the AIL.
  			 *
  			 * xfs_trans_ail_update() drops the AIL lock.
  			 */
  			xfs_trans_ail_update(ailp, lip, item_lsn);
  		} else {
  			spin_unlock(&ailp->xa_lock);
  		}
  
  		/*
  		 * Now that we've repositioned the item in the AIL,
  		 * unpin it so it can be flushed. Pass information
  		 * about buffer stale state down from the log item
  		 * flags, if anyone else stales the buffer we do not
  		 * want to pay any attention to it.
  		 */
  		IOP_UNPIN(lip, lidp->lid_flags & XFS_LID_BUF_STALE);
  	}
  }
  