/*
   *   Copyright (C) International Business Machines Corp., 2000-2005
   *   Portions Copyright (C) Christoph Hellwig, 2001-2002
   *
   *   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; either version 2 of the License, or

   *   (at your option) any later version.

   *

   *   This program is distributed in the hope that it will 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 to the Free Software

   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  
  /*

   *	jfs_txnmgr.c: transaction manager

   *
   * notes:
   * transaction starts with txBegin() and ends with txCommit()
   * or txAbort().
   *
   * tlock is acquired at the time of update;
   * (obviate scan at commit time for xtree and dtree)
   * tlock and mp points to each other;
   * (no hashlist for mp -> tlock).
   *
   * special cases:
   * tlock on in-memory inode:
   * in-place tlock in the in-memory inode itself;
   * converted to page lock by iWrite() at commit time.
   *
   * tlock during write()/mmap() under anonymous transaction (tid = 0):
   * transferred (?) to transaction at commit time.
   *
   * use the page itself to update allocation maps
   * (obviate intermediate replication of allocation/deallocation data)
   * hold on to mp+lock thru update of maps
   */

  #include <linux/fs.h>
  #include <linux/vmalloc.h>

  #include <linux/completion.h>

  #include <linux/freezer.h>

  #include <linux/module.h>
  #include <linux/moduleparam.h>

  #include <linux/kthread.h>

  #include <linux/seq_file.h>

  #include "jfs_incore.h"

  #include "jfs_inode.h"

  #include "jfs_filsys.h"
  #include "jfs_metapage.h"
  #include "jfs_dinode.h"
  #include "jfs_imap.h"
  #include "jfs_dmap.h"
  #include "jfs_superblock.h"
  #include "jfs_debug.h"
  
  /*

   *	transaction management structures

   */
  static struct {
  	int freetid;		/* index of a free tid structure */
  	int freelock;		/* index first free lock word */
  	wait_queue_head_t freewait;	/* eventlist of free tblock */
  	wait_queue_head_t freelockwait;	/* eventlist of free tlock */
  	wait_queue_head_t lowlockwait;	/* eventlist of ample tlocks */
  	int tlocksInUse;	/* Number of tlocks in use */
  	spinlock_t LazyLock;	/* synchronize sync_queue & unlock_queue */
  /*	struct tblock *sync_queue; * Transactions waiting for data sync */
  	struct list_head unlock_queue;	/* Txns waiting to be released */
  	struct list_head anon_list;	/* inodes having anonymous txns */
  	struct list_head anon_list2;	/* inodes having anonymous txns
  					   that couldn't be sync'ed */
  } TxAnchor;
  
  int jfs_tlocks_low;		/* Indicates low number of available tlocks */
  
  #ifdef CONFIG_JFS_STATISTICS
  static struct {
  	uint txBegin;
  	uint txBegin_barrier;
  	uint txBegin_lockslow;
  	uint txBegin_freetid;
  	uint txBeginAnon;
  	uint txBeginAnon_barrier;
  	uint txBeginAnon_lockslow;
  	uint txLockAlloc;
  	uint txLockAlloc_freelock;
  } TxStat;
  #endif
  
  static int nTxBlock = -1;	/* number of transaction blocks */
  module_param(nTxBlock, int, 0);
  MODULE_PARM_DESC(nTxBlock,
  		 "Number of transaction blocks (max:65536)");
  
  static int nTxLock = -1;	/* number of transaction locks */
  module_param(nTxLock, int, 0);
  MODULE_PARM_DESC(nTxLock,
  		 "Number of transaction locks (max:65536)");

  struct tblock *TxBlock;	/* transaction block table */
  static int TxLockLWM;	/* Low water mark for number of txLocks used */
  static int TxLockHWM;	/* High water mark for number of txLocks used */
  static int TxLockVHWM;	/* Very High water mark */
  struct tlock *TxLock;	/* transaction lock table */

  /*

   *	transaction management lock

   */
  static DEFINE_SPINLOCK(jfsTxnLock);

  #define TXN_LOCK()		spin_lock(&jfsTxnLock)
  #define TXN_UNLOCK()		spin_unlock(&jfsTxnLock)

  
  #define LAZY_LOCK_INIT()	spin_lock_init(&TxAnchor.LazyLock);
  #define LAZY_LOCK(flags)	spin_lock_irqsave(&TxAnchor.LazyLock, flags)
  #define LAZY_UNLOCK(flags) spin_unlock_irqrestore(&TxAnchor.LazyLock, flags)

  static DECLARE_WAIT_QUEUE_HEAD(jfs_commit_thread_wait);

  static int jfs_commit_thread_waking;
  
  /*
   * Retry logic exist outside these macros to protect from spurrious wakeups.
   */
  static inline void TXN_SLEEP_DROP_LOCK(wait_queue_head_t * event)
  {
  	DECLARE_WAITQUEUE(wait, current);
  
  	add_wait_queue(event, &wait);
  	set_current_state(TASK_UNINTERRUPTIBLE);
  	TXN_UNLOCK();

  	io_schedule();

  	__set_current_state(TASK_RUNNING);

  	remove_wait_queue(event, &wait);
  }
  
  #define TXN_SLEEP(event)\
  {\
  	TXN_SLEEP_DROP_LOCK(event);\
  	TXN_LOCK();\
  }
  
  #define TXN_WAKEUP(event) wake_up_all(event)

  /*

   *	statistics

   */
  static struct {
  	tid_t maxtid;		/* 4: biggest tid ever used */
  	lid_t maxlid;		/* 4: biggest lid ever used */
  	int ntid;		/* 4: # of transactions performed */
  	int nlid;		/* 4: # of tlocks acquired */
  	int waitlock;		/* 4: # of tlock wait */
  } stattx;

  /*
   * forward references
   */
  static int diLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
  		struct tlock * tlck, struct commit * cd);
  static int dataLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
  		struct tlock * tlck);
  static void dtLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
  		struct tlock * tlck);
  static void mapLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
  		struct tlock * tlck);
  static void txAllocPMap(struct inode *ip, struct maplock * maplock,
  		struct tblock * tblk);
  static void txForce(struct tblock * tblk);
  static int txLog(struct jfs_log * log, struct tblock * tblk,
  		struct commit * cd);
  static void txUpdateMap(struct tblock * tblk);
  static void txRelease(struct tblock * tblk);
  static void xtLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
  	   struct tlock * tlck);
  static void LogSyncRelease(struct metapage * mp);
  
  /*

   *		transaction block/lock management
   *		---------------------------------

   */
  
  /*
   * Get a transaction lock from the free list.  If the number in use is
   * greater than the high water mark, wake up the sync daemon.  This should
   * free some anonymous transaction locks.  (TXN_LOCK must be held.)
   */
  static lid_t txLockAlloc(void)
  {
  	lid_t lid;
  
  	INCREMENT(TxStat.txLockAlloc);
  	if (!TxAnchor.freelock) {
  		INCREMENT(TxStat.txLockAlloc_freelock);
  	}
  
  	while (!(lid = TxAnchor.freelock))
  		TXN_SLEEP(&TxAnchor.freelockwait);
  	TxAnchor.freelock = TxLock[lid].next;
  	HIGHWATERMARK(stattx.maxlid, lid);
  	if ((++TxAnchor.tlocksInUse > TxLockHWM) && (jfs_tlocks_low == 0)) {
  		jfs_info("txLockAlloc tlocks low");
  		jfs_tlocks_low = 1;

  		wake_up_process(jfsSyncThread);

  	}
  
  	return lid;
  }
  
  static void txLockFree(lid_t lid)
  {

  	TxLock[lid].tid = 0;

  	TxLock[lid].next = TxAnchor.freelock;
  	TxAnchor.freelock = lid;
  	TxAnchor.tlocksInUse--;
  	if (jfs_tlocks_low && (TxAnchor.tlocksInUse < TxLockLWM)) {
  		jfs_info("txLockFree jfs_tlocks_low no more");
  		jfs_tlocks_low = 0;
  		TXN_WAKEUP(&TxAnchor.lowlockwait);
  	}
  	TXN_WAKEUP(&TxAnchor.freelockwait);
  }
  
  /*

   * NAME:	txInit()

   *

   * FUNCTION:	initialize transaction management structures

   *
   * RETURN:
   *
   * serialization: single thread at jfs_init()
   */
  int txInit(void)
  {
  	int k, size;
  	struct sysinfo si;
  
  	/* Set defaults for nTxLock and nTxBlock if unset */
  
  	if (nTxLock == -1) {
  		if (nTxBlock == -1) {
  			/* Base default on memory size */
  			si_meminfo(&si);
  			if (si.totalram > (256 * 1024)) /* 1 GB */
  				nTxLock = 64 * 1024;
  			else
  				nTxLock = si.totalram >> 2;
  		} else if (nTxBlock > (8 * 1024))
  			nTxLock = 64 * 1024;
  		else
  			nTxLock = nTxBlock << 3;
  	}
  	if (nTxBlock == -1)
  		nTxBlock = nTxLock >> 3;
  
  	/* Verify tunable parameters */
  	if (nTxBlock < 16)
  		nTxBlock = 16;	/* No one should set it this low */
  	if (nTxBlock > 65536)
  		nTxBlock = 65536;
  	if (nTxLock < 256)
  		nTxLock = 256;	/* No one should set it this low */
  	if (nTxLock > 65536)
  		nTxLock = 65536;
  
  	printk(KERN_INFO "JFS: nTxBlock = %d, nTxLock = %d
  ",
  	       nTxBlock, nTxLock);
  	/*
  	 * initialize transaction block (tblock) table
  	 *
  	 * transaction id (tid) = tblock index
  	 * tid = 0 is reserved.
  	 */
  	TxLockLWM = (nTxLock * 4) / 10;
  	TxLockHWM = (nTxLock * 7) / 10;
  	TxLockVHWM = (nTxLock * 8) / 10;
  
  	size = sizeof(struct tblock) * nTxBlock;

  	TxBlock = vmalloc(size);

  	if (TxBlock == NULL)
  		return -ENOMEM;
  
  	for (k = 1; k < nTxBlock - 1; k++) {
  		TxBlock[k].next = k + 1;
  		init_waitqueue_head(&TxBlock[k].gcwait);
  		init_waitqueue_head(&TxBlock[k].waitor);
  	}
  	TxBlock[k].next = 0;
  	init_waitqueue_head(&TxBlock[k].gcwait);
  	init_waitqueue_head(&TxBlock[k].waitor);
  
  	TxAnchor.freetid = 1;
  	init_waitqueue_head(&TxAnchor.freewait);
  
  	stattx.maxtid = 1;	/* statistics */
  
  	/*
  	 * initialize transaction lock (tlock) table
  	 *
  	 * transaction lock id = tlock index
  	 * tlock id = 0 is reserved.
  	 */
  	size = sizeof(struct tlock) * nTxLock;

  	TxLock = vmalloc(size);

  	if (TxLock == NULL) {
  		vfree(TxBlock);
  		return -ENOMEM;
  	}
  
  	/* initialize tlock table */
  	for (k = 1; k < nTxLock - 1; k++)
  		TxLock[k].next = k + 1;
  	TxLock[k].next = 0;
  	init_waitqueue_head(&TxAnchor.freelockwait);
  	init_waitqueue_head(&TxAnchor.lowlockwait);
  
  	TxAnchor.freelock = 1;
  	TxAnchor.tlocksInUse = 0;
  	INIT_LIST_HEAD(&TxAnchor.anon_list);
  	INIT_LIST_HEAD(&TxAnchor.anon_list2);
  
  	LAZY_LOCK_INIT();
  	INIT_LIST_HEAD(&TxAnchor.unlock_queue);
  
  	stattx.maxlid = 1;	/* statistics */
  
  	return 0;
  }
  
  /*

   * NAME:	txExit()

   *

   * FUNCTION:	clean up when module is unloaded

   */
  void txExit(void)
  {
  	vfree(TxLock);
  	TxLock = NULL;
  	vfree(TxBlock);
  	TxBlock = NULL;
  }

  /*

   * NAME:	txBegin()

   *

   * FUNCTION:	start a transaction.

   *

   * PARAMETER:	sb	- superblock
   *		flag	- force for nested tx;

   *
   * RETURN:	tid	- transaction id
   *
   * note: flag force allows to start tx for nested tx
   * to prevent deadlock on logsync barrier;
   */
  tid_t txBegin(struct super_block *sb, int flag)
  {
  	tid_t t;
  	struct tblock *tblk;
  	struct jfs_log *log;
  
  	jfs_info("txBegin: flag = 0x%x", flag);
  	log = JFS_SBI(sb)->log;
  
  	TXN_LOCK();
  
  	INCREMENT(TxStat.txBegin);
  
        retry:
  	if (!(flag & COMMIT_FORCE)) {
  		/*
  		 * synchronize with logsync barrier
  		 */
  		if (test_bit(log_SYNCBARRIER, &log->flag) ||
  		    test_bit(log_QUIESCE, &log->flag)) {
  			INCREMENT(TxStat.txBegin_barrier);
  			TXN_SLEEP(&log->syncwait);
  			goto retry;
  		}
  	}
  	if (flag == 0) {
  		/*
  		 * Don't begin transaction if we're getting starved for tlocks
  		 * unless COMMIT_FORCE or COMMIT_INODE (which may ultimately
  		 * free tlocks)
  		 */
  		if (TxAnchor.tlocksInUse > TxLockVHWM) {
  			INCREMENT(TxStat.txBegin_lockslow);
  			TXN_SLEEP(&TxAnchor.lowlockwait);
  			goto retry;
  		}
  	}
  
  	/*
  	 * allocate transaction id/block
  	 */
  	if ((t = TxAnchor.freetid) == 0) {
  		jfs_info("txBegin: waiting for free tid");
  		INCREMENT(TxStat.txBegin_freetid);
  		TXN_SLEEP(&TxAnchor.freewait);
  		goto retry;
  	}
  
  	tblk = tid_to_tblock(t);
  
  	if ((tblk->next == 0) && !(flag & COMMIT_FORCE)) {
  		/* Don't let a non-forced transaction take the last tblk */
  		jfs_info("txBegin: waiting for free tid");
  		INCREMENT(TxStat.txBegin_freetid);
  		TXN_SLEEP(&TxAnchor.freewait);
  		goto retry;
  	}
  
  	TxAnchor.freetid = tblk->next;
  
  	/*
  	 * initialize transaction
  	 */
  
  	/*
  	 * We can't zero the whole thing or we screw up another thread being
  	 * awakened after sleeping on tblk->waitor
  	 *
  	 * memset(tblk, 0, sizeof(struct tblock));
  	 */
  	tblk->next = tblk->last = tblk->xflag = tblk->flag = tblk->lsn = 0;
  
  	tblk->sb = sb;
  	++log->logtid;
  	tblk->logtid = log->logtid;
  
  	++log->active;
  
  	HIGHWATERMARK(stattx.maxtid, t);	/* statistics */
  	INCREMENT(stattx.ntid);	/* statistics */
  
  	TXN_UNLOCK();
  
  	jfs_info("txBegin: returning tid = %d", t);
  
  	return t;
  }

  /*

   * NAME:	txBeginAnon()

   *

   * FUNCTION:	start an anonymous transaction.

   *		Blocks if logsync or available tlocks are low to prevent
   *		anonymous tlocks from depleting supply.
   *

   * PARAMETER:	sb	- superblock

   *
   * RETURN:	none
   */
  void txBeginAnon(struct super_block *sb)
  {
  	struct jfs_log *log;
  
  	log = JFS_SBI(sb)->log;
  
  	TXN_LOCK();
  	INCREMENT(TxStat.txBeginAnon);
  
        retry:
  	/*
  	 * synchronize with logsync barrier
  	 */
  	if (test_bit(log_SYNCBARRIER, &log->flag) ||
  	    test_bit(log_QUIESCE, &log->flag)) {
  		INCREMENT(TxStat.txBeginAnon_barrier);
  		TXN_SLEEP(&log->syncwait);
  		goto retry;
  	}
  
  	/*
  	 * Don't begin transaction if we're getting starved for tlocks
  	 */
  	if (TxAnchor.tlocksInUse > TxLockVHWM) {
  		INCREMENT(TxStat.txBeginAnon_lockslow);
  		TXN_SLEEP(&TxAnchor.lowlockwait);
  		goto retry;
  	}
  	TXN_UNLOCK();
  }

  /*

   *	txEnd()

   *
   * function: free specified transaction block.
   *

   *	logsync barrier processing:

   *
   * serialization:
   */
  void txEnd(tid_t tid)
  {
  	struct tblock *tblk = tid_to_tblock(tid);
  	struct jfs_log *log;
  
  	jfs_info("txEnd: tid = %d", tid);
  	TXN_LOCK();
  
  	/*
  	 * wakeup transactions waiting on the page locked
  	 * by the current transaction
  	 */
  	TXN_WAKEUP(&tblk->waitor);
  
  	log = JFS_SBI(tblk->sb)->log;
  
  	/*
  	 * Lazy commit thread can't free this guy until we mark it UNLOCKED,
  	 * otherwise, we would be left with a transaction that may have been
  	 * reused.
  	 *
  	 * Lazy commit thread will turn off tblkGC_LAZY before calling this
  	 * routine.
  	 */
  	if (tblk->flag & tblkGC_LAZY) {
  		jfs_info("txEnd called w/lazy tid: %d, tblk = 0x%p", tid, tblk);
  		TXN_UNLOCK();
  
  		spin_lock_irq(&log->gclock);	// LOGGC_LOCK
  		tblk->flag |= tblkGC_UNLOCKED;
  		spin_unlock_irq(&log->gclock);	// LOGGC_UNLOCK
  		return;
  	}
  
  	jfs_info("txEnd: tid: %d, tblk = 0x%p", tid, tblk);
  
  	assert(tblk->next == 0);
  
  	/*
  	 * insert tblock back on freelist
  	 */
  	tblk->next = TxAnchor.freetid;
  	TxAnchor.freetid = tid;
  
  	/*
  	 * mark the tblock not active
  	 */
  	if (--log->active == 0) {
  		clear_bit(log_FLUSH, &log->flag);
  
  		/*
  		 * synchronize with logsync barrier
  		 */
  		if (test_bit(log_SYNCBARRIER, &log->flag)) {

  			TXN_UNLOCK();
  
  			/* write dirty metadata & forward log syncpt */
  			jfs_syncpt(log, 1);

  			jfs_info("log barrier off: 0x%x", log->lsn);
  
  			/* enable new transactions start */
  			clear_bit(log_SYNCBARRIER, &log->flag);
  
  			/* wakeup all waitors for logsync barrier */
  			TXN_WAKEUP(&log->syncwait);

  			goto wakeup;

  		}
  	}

  	TXN_UNLOCK();
  wakeup:

  	/*
  	 * wakeup all waitors for a free tblock
  	 */
  	TXN_WAKEUP(&TxAnchor.freewait);

  }

  /*

   *	txLock()

   *
   * function: acquire a transaction lock on the specified <mp>
   *
   * parameter:
   *

   * return:	transaction lock id

   *
   * serialization:
   */
  struct tlock *txLock(tid_t tid, struct inode *ip, struct metapage * mp,
  		     int type)
  {
  	struct jfs_inode_info *jfs_ip = JFS_IP(ip);
  	int dir_xtree = 0;
  	lid_t lid;
  	tid_t xtid;
  	struct tlock *tlck;
  	struct xtlock *xtlck;
  	struct linelock *linelock;
  	xtpage_t *p;
  	struct tblock *tblk;
  
  	TXN_LOCK();
  
  	if (S_ISDIR(ip->i_mode) && (type & tlckXTREE) &&
  	    !(mp->xflag & COMMIT_PAGE)) {
  		/*
  		 * Directory inode is special.  It can have both an xtree tlock
  		 * and a dtree tlock associated with it.
  		 */
  		dir_xtree = 1;
  		lid = jfs_ip->xtlid;
  	} else
  		lid = mp->lid;
  
  	/* is page not locked by a transaction ? */
  	if (lid == 0)
  		goto allocateLock;
  
  	jfs_info("txLock: tid:%d ip:0x%p mp:0x%p lid:%d", tid, ip, mp, lid);
  
  	/* is page locked by the requester transaction ? */
  	tlck = lid_to_tlock(lid);

  	if ((xtid = tlck->tid) == tid) {
  		TXN_UNLOCK();

  		goto grantLock;

  	}

  
  	/*
  	 * is page locked by anonymous transaction/lock ?
  	 *
  	 * (page update without transaction (i.e., file write) is
  	 * locked under anonymous transaction tid = 0:
  	 * anonymous tlocks maintained on anonymous tlock list of
  	 * the inode of the page and available to all anonymous
  	 * transactions until txCommit() time at which point
  	 * they are transferred to the transaction tlock list of

  	 * the committing transaction of the inode)

  	 */
  	if (xtid == 0) {
  		tlck->tid = tid;

  		TXN_UNLOCK();

  		tblk = tid_to_tblock(tid);
  		/*
  		 * The order of the tlocks in the transaction is important
  		 * (during truncate, child xtree pages must be freed before
  		 * parent's tlocks change the working map).
  		 * Take tlock off anonymous list and add to tail of
  		 * transaction list
  		 *
  		 * Note:  We really need to get rid of the tid & lid and
  		 * use list_head's.  This code is getting UGLY!
  		 */
  		if (jfs_ip->atlhead == lid) {
  			if (jfs_ip->atltail == lid) {
  				/* only anonymous txn.
  				 * Remove from anon_list
  				 */

  				TXN_LOCK();

  				list_del_init(&jfs_ip->anon_inode_list);

  				TXN_UNLOCK();

  			}
  			jfs_ip->atlhead = tlck->next;
  		} else {
  			lid_t last;
  			for (last = jfs_ip->atlhead;
  			     lid_to_tlock(last)->next != lid;
  			     last = lid_to_tlock(last)->next) {
  				assert(last);
  			}
  			lid_to_tlock(last)->next = tlck->next;
  			if (jfs_ip->atltail == lid)
  				jfs_ip->atltail = last;
  		}
  
  		/* insert the tlock at tail of transaction tlock list */
  
  		if (tblk->next)
  			lid_to_tlock(tblk->last)->next = lid;
  		else
  			tblk->next = lid;
  		tlck->next = 0;
  		tblk->last = lid;
  
  		goto grantLock;
  	}
  
  	goto waitLock;
  
  	/*
  	 * allocate a tlock
  	 */
        allocateLock:
  	lid = txLockAlloc();
  	tlck = lid_to_tlock(lid);
  
  	/*
  	 * initialize tlock
  	 */
  	tlck->tid = tid;

  	TXN_UNLOCK();

  	/* mark tlock for meta-data page */
  	if (mp->xflag & COMMIT_PAGE) {
  
  		tlck->flag = tlckPAGELOCK;
  
  		/* mark the page dirty and nohomeok */

  		metapage_nohomeok(mp);

  
  		jfs_info("locking mp = 0x%p, nohomeok = %d tid = %d tlck = 0x%p",

  			 mp, mp->nohomeok, tid, tlck);

  
  		/* if anonymous transaction, and buffer is on the group
  		 * commit synclist, mark inode to show this.  This will
  		 * prevent the buffer from being marked nohomeok for too
  		 * long a time.
  		 */
  		if ((tid == 0) && mp->lsn)
  			set_cflag(COMMIT_Synclist, ip);
  	}
  	/* mark tlock for in-memory inode */
  	else
  		tlck->flag = tlckINODELOCK;

  	if (S_ISDIR(ip->i_mode))
  		tlck->flag |= tlckDIRECTORY;

  	tlck->type = 0;
  
  	/* bind the tlock and the page */
  	tlck->ip = ip;
  	tlck->mp = mp;
  	if (dir_xtree)
  		jfs_ip->xtlid = lid;
  	else
  		mp->lid = lid;
  
  	/*
  	 * enqueue transaction lock to transaction/inode
  	 */
  	/* insert the tlock at tail of transaction tlock list */
  	if (tid) {
  		tblk = tid_to_tblock(tid);
  		if (tblk->next)
  			lid_to_tlock(tblk->last)->next = lid;
  		else
  			tblk->next = lid;
  		tlck->next = 0;
  		tblk->last = lid;
  	}
  	/* anonymous transaction:
  	 * insert the tlock at head of inode anonymous tlock list
  	 */
  	else {
  		tlck->next = jfs_ip->atlhead;
  		jfs_ip->atlhead = lid;
  		if (tlck->next == 0) {
  			/* This inode's first anonymous transaction */
  			jfs_ip->atltail = lid;

  			TXN_LOCK();

  			list_add_tail(&jfs_ip->anon_inode_list,
  				      &TxAnchor.anon_list);

  			TXN_UNLOCK();

  		}
  	}
  
  	/* initialize type dependent area for linelock */
  	linelock = (struct linelock *) & tlck->lock;
  	linelock->next = 0;
  	linelock->flag = tlckLINELOCK;
  	linelock->maxcnt = TLOCKSHORT;
  	linelock->index = 0;
  
  	switch (type & tlckTYPE) {
  	case tlckDTREE:
  		linelock->l2linesize = L2DTSLOTSIZE;
  		break;
  
  	case tlckXTREE:
  		linelock->l2linesize = L2XTSLOTSIZE;
  
  		xtlck = (struct xtlock *) linelock;
  		xtlck->header.offset = 0;
  		xtlck->header.length = 2;
  
  		if (type & tlckNEW) {
  			xtlck->lwm.offset = XTENTRYSTART;
  		} else {
  			if (mp->xflag & COMMIT_PAGE)
  				p = (xtpage_t *) mp->data;
  			else
  				p = &jfs_ip->i_xtroot;
  			xtlck->lwm.offset =
  			    le16_to_cpu(p->header.nextindex);
  		}
  		xtlck->lwm.length = 0;	/* ! */
  		xtlck->twm.offset = 0;
  		xtlck->hwm.offset = 0;
  
  		xtlck->index = 2;
  		break;
  
  	case tlckINODE:
  		linelock->l2linesize = L2INODESLOTSIZE;
  		break;
  
  	case tlckDATA:
  		linelock->l2linesize = L2DATASLOTSIZE;
  		break;
  
  	default:
  		jfs_err("UFO tlock:0x%p", tlck);
  	}
  
  	/*
  	 * update tlock vector
  	 */
        grantLock:
  	tlck->type |= type;

  	return tlck;
  
  	/*
  	 * page is being locked by another transaction:
  	 */
        waitLock:
  	/* Only locks on ipimap or ipaimap should reach here */
  	/* assert(jfs_ip->fileset == AGGREGATE_I); */
  	if (jfs_ip->fileset != AGGREGATE_I) {

  		printk(KERN_ERR "txLock: trying to lock locked page!");

  		print_hex_dump(KERN_ERR, "ip: ", DUMP_PREFIX_ADDRESS, 16, 4,
  			       ip, sizeof(*ip), 0);
  		print_hex_dump(KERN_ERR, "mp: ", DUMP_PREFIX_ADDRESS, 16, 4,
  			       mp, sizeof(*mp), 0);
  		print_hex_dump(KERN_ERR, "Locker's tblock: ",
  			       DUMP_PREFIX_ADDRESS, 16, 4, tid_to_tblock(tid),
  			       sizeof(struct tblock), 0);
  		print_hex_dump(KERN_ERR, "Tlock: ", DUMP_PREFIX_ADDRESS, 16, 4,
  			       tlck, sizeof(*tlck), 0);

  		BUG();
  	}
  	INCREMENT(stattx.waitlock);	/* statistics */

  	TXN_UNLOCK();

  	release_metapage(mp);

  	TXN_LOCK();

  	xtid = tlck->tid;	/* reacquire after dropping TXN_LOCK */

  
  	jfs_info("txLock: in waitLock, tid = %d, xtid = %d, lid = %d",
  		 tid, xtid, lid);

  
  	/* Recheck everything since dropping TXN_LOCK */
  	if (xtid && (tlck->mp == mp) && (mp->lid == lid))
  		TXN_SLEEP_DROP_LOCK(&tid_to_tblock(xtid)->waitor);
  	else
  		TXN_UNLOCK();

  	jfs_info("txLock: awakened     tid = %d, lid = %d", tid, lid);
  
  	return NULL;
  }

  /*

   * NAME:	txRelease()

   *

   * FUNCTION:	Release buffers associated with transaction locks, but don't

   *		mark homeok yet.  The allows other transactions to modify
   *		buffers, but won't let them go to disk until commit record
   *		actually gets written.
   *
   * PARAMETER:

   *		tblk	-

   *

   * RETURN:	Errors from subroutines.

   */
  static void txRelease(struct tblock * tblk)
  {
  	struct metapage *mp;
  	lid_t lid;
  	struct tlock *tlck;
  
  	TXN_LOCK();
  
  	for (lid = tblk->next; lid; lid = tlck->next) {
  		tlck = lid_to_tlock(lid);
  		if ((mp = tlck->mp) != NULL &&
  		    (tlck->type & tlckBTROOT) == 0) {
  			assert(mp->xflag & COMMIT_PAGE);
  			mp->lid = 0;
  		}
  	}
  
  	/*
  	 * wakeup transactions waiting on a page locked
  	 * by the current transaction
  	 */
  	TXN_WAKEUP(&tblk->waitor);
  
  	TXN_UNLOCK();
  }

  /*

   * NAME:	txUnlock()

   *

   * FUNCTION:	Initiates pageout of pages modified by tid in journalled
   *		objects and frees their lockwords.

   */
  static void txUnlock(struct tblock * tblk)
  {
  	struct tlock *tlck;
  	struct linelock *linelock;
  	lid_t lid, next, llid, k;
  	struct metapage *mp;
  	struct jfs_log *log;
  	int difft, diffp;

  	unsigned long flags;

  
  	jfs_info("txUnlock: tblk = 0x%p", tblk);
  	log = JFS_SBI(tblk->sb)->log;
  
  	/*
  	 * mark page under tlock homeok (its log has been written):
  	 */
  	for (lid = tblk->next; lid; lid = next) {
  		tlck = lid_to_tlock(lid);
  		next = tlck->next;
  
  		jfs_info("unlocking lid = %d, tlck = 0x%p", lid, tlck);
  
  		/* unbind page from tlock */
  		if ((mp = tlck->mp) != NULL &&
  		    (tlck->type & tlckBTROOT) == 0) {
  			assert(mp->xflag & COMMIT_PAGE);
  
  			/* hold buffer

  			 */

  			hold_metapage(mp);

  			assert(mp->nohomeok > 0);
  			_metapage_homeok(mp);

  
  			/* inherit younger/larger clsn */

  			LOGSYNC_LOCK(log, flags);

  			if (mp->clsn) {
  				logdiff(difft, tblk->clsn, log);
  				logdiff(diffp, mp->clsn, log);
  				if (difft > diffp)
  					mp->clsn = tblk->clsn;
  			} else
  				mp->clsn = tblk->clsn;

  			LOGSYNC_UNLOCK(log, flags);

  
  			assert(!(tlck->flag & tlckFREEPAGE));

  			put_metapage(mp);

  		}
  
  		/* insert tlock, and linelock(s) of the tlock if any,
  		 * at head of freelist
  		 */
  		TXN_LOCK();
  
  		llid = ((struct linelock *) & tlck->lock)->next;
  		while (llid) {
  			linelock = (struct linelock *) lid_to_tlock(llid);
  			k = linelock->next;
  			txLockFree(llid);
  			llid = k;
  		}
  		txLockFree(lid);
  
  		TXN_UNLOCK();
  	}
  	tblk->next = tblk->last = 0;
  
  	/*
  	 * remove tblock from logsynclist
  	 * (allocation map pages inherited lsn of tblk and
  	 * has been inserted in logsync list at txUpdateMap())
  	 */
  	if (tblk->lsn) {

  		LOGSYNC_LOCK(log, flags);

  		log->count--;
  		list_del(&tblk->synclist);

  		LOGSYNC_UNLOCK(log, flags);

  	}
  }

  /*

   *	txMaplock()

   *
   * function: allocate a transaction lock for freed page/entry;

   *	for freed page, maplock is used as xtlock/dtlock type;

   */
  struct tlock *txMaplock(tid_t tid, struct inode *ip, int type)
  {
  	struct jfs_inode_info *jfs_ip = JFS_IP(ip);
  	lid_t lid;
  	struct tblock *tblk;
  	struct tlock *tlck;
  	struct maplock *maplock;
  
  	TXN_LOCK();
  
  	/*
  	 * allocate a tlock
  	 */
  	lid = txLockAlloc();
  	tlck = lid_to_tlock(lid);
  
  	/*
  	 * initialize tlock
  	 */
  	tlck->tid = tid;
  
  	/* bind the tlock and the object */
  	tlck->flag = tlckINODELOCK;

  	if (S_ISDIR(ip->i_mode))
  		tlck->flag |= tlckDIRECTORY;

  	tlck->ip = ip;
  	tlck->mp = NULL;
  
  	tlck->type = type;
  
  	/*
  	 * enqueue transaction lock to transaction/inode
  	 */
  	/* insert the tlock at tail of transaction tlock list */
  	if (tid) {
  		tblk = tid_to_tblock(tid);
  		if (tblk->next)
  			lid_to_tlock(tblk->last)->next = lid;
  		else
  			tblk->next = lid;
  		tlck->next = 0;
  		tblk->last = lid;
  	}
  	/* anonymous transaction:
  	 * insert the tlock at head of inode anonymous tlock list
  	 */
  	else {
  		tlck->next = jfs_ip->atlhead;
  		jfs_ip->atlhead = lid;
  		if (tlck->next == 0) {
  			/* This inode's first anonymous transaction */
  			jfs_ip->atltail = lid;
  			list_add_tail(&jfs_ip->anon_inode_list,
  				      &TxAnchor.anon_list);
  		}
  	}
  
  	TXN_UNLOCK();
  
  	/* initialize type dependent area for maplock */
  	maplock = (struct maplock *) & tlck->lock;
  	maplock->next = 0;
  	maplock->maxcnt = 0;
  	maplock->index = 0;
  
  	return tlck;
  }

  /*

   *	txLinelock()

   *
   * function: allocate a transaction lock for log vector list
   */
  struct linelock *txLinelock(struct linelock * tlock)
  {
  	lid_t lid;
  	struct tlock *tlck;
  	struct linelock *linelock;
  
  	TXN_LOCK();
  
  	/* allocate a TxLock structure */
  	lid = txLockAlloc();
  	tlck = lid_to_tlock(lid);
  
  	TXN_UNLOCK();
  
  	/* initialize linelock */
  	linelock = (struct linelock *) tlck;
  	linelock->next = 0;
  	linelock->flag = tlckLINELOCK;
  	linelock->maxcnt = TLOCKLONG;
  	linelock->index = 0;

  	if (tlck->flag & tlckDIRECTORY)
  		linelock->flag |= tlckDIRECTORY;

  
  	/* append linelock after tlock */
  	linelock->next = tlock->next;
  	tlock->next = lid;
  
  	return linelock;
  }

  /*

   *		transaction commit management
   *		-----------------------------

   */
  
  /*

   * NAME:	txCommit()
   *
   * FUNCTION:	commit the changes to the objects specified in
   *		clist.  For journalled segments only the
   *		changes of the caller are committed, ie by tid.
   *		for non-journalled segments the data are flushed to
   *		disk and then the change to the disk inode and indirect
   *		blocks committed (so blocks newly allocated to the
   *		segment will be made a part of the segment atomically).
   *
   *		all of the segments specified in clist must be in
   *		one file system. no more than 6 segments are needed
   *		to handle all unix svcs.
   *
   *		if the i_nlink field (i.e. disk inode link count)
   *		is zero, and the type of inode is a regular file or
   *		directory, or symbolic link , the inode is truncated
   *		to zero length. the truncation is committed but the
   *		VM resources are unaffected until it is closed (see
   *		iput and iclose).

   *
   * PARAMETER:
   *
   * RETURN:
   *
   * serialization:

   *		on entry the inode lock on each segment is assumed
   *		to be held.

   *
   * i/o error:
   */
  int txCommit(tid_t tid,		/* transaction identifier */
  	     int nip,		/* number of inodes to commit */
  	     struct inode **iplist,	/* list of inode to commit */
  	     int flag)
  {
  	int rc = 0;
  	struct commit cd;
  	struct jfs_log *log;
  	struct tblock *tblk;
  	struct lrd *lrd;

  	struct inode *ip;
  	struct jfs_inode_info *jfs_ip;
  	int k, n;
  	ino_t top;
  	struct super_block *sb;
  
  	jfs_info("txCommit, tid = %d, flag = %d", tid, flag);
  	/* is read-only file system ? */
  	if (isReadOnly(iplist[0])) {
  		rc = -EROFS;
  		goto TheEnd;
  	}
  
  	sb = cd.sb = iplist[0]->i_sb;
  	cd.tid = tid;
  
  	if (tid == 0)
  		tid = txBegin(sb, 0);
  	tblk = tid_to_tblock(tid);
  
  	/*
  	 * initialize commit structure
  	 */
  	log = JFS_SBI(sb)->log;
  	cd.log = log;
  
  	/* initialize log record descriptor in commit */
  	lrd = &cd.lrd;
  	lrd->logtid = cpu_to_le32(tblk->logtid);
  	lrd->backchain = 0;
  
  	tblk->xflag |= flag;
  
  	if ((flag & (COMMIT_FORCE | COMMIT_SYNC)) == 0)
  		tblk->xflag |= COMMIT_LAZY;
  	/*

  	 *	prepare non-journaled objects for commit

  	 *
  	 * flush data pages of non-journaled file
  	 * to prevent the file getting non-initialized disk blocks
  	 * in case of crash.
  	 * (new blocks - )
  	 */
  	cd.iplist = iplist;
  	cd.nip = nip;
  
  	/*

  	 *	acquire transaction lock on (on-disk) inodes

  	 *
  	 * update on-disk inode from in-memory inode
  	 * acquiring transaction locks for AFTER records
  	 * on the on-disk inode of file object
  	 *
  	 * sort the inodes array by inode number in descending order
  	 * to prevent deadlock when acquiring transaction lock
  	 * of on-disk inodes on multiple on-disk inode pages by
  	 * multiple concurrent transactions
  	 */
  	for (k = 0; k < cd.nip; k++) {
  		top = (cd.iplist[k])->i_ino;
  		for (n = k + 1; n < cd.nip; n++) {
  			ip = cd.iplist[n];
  			if (ip->i_ino > top) {
  				top = ip->i_ino;
  				cd.iplist[n] = cd.iplist[k];
  				cd.iplist[k] = ip;
  			}
  		}
  
  		ip = cd.iplist[k];
  		jfs_ip = JFS_IP(ip);
  
  		/*
  		 * BUGBUG - This code has temporarily been removed.  The
  		 * intent is to ensure that any file data is written before
  		 * the metadata is committed to the journal.  This prevents
  		 * uninitialized data from appearing in a file after the
  		 * journal has been replayed.  (The uninitialized data
  		 * could be sensitive data removed by another user.)
  		 *
  		 * The problem now is that we are holding the IWRITELOCK
  		 * on the inode, and calling filemap_fdatawrite on an
  		 * unmapped page will cause a deadlock in jfs_get_block.
  		 *
  		 * The long term solution is to pare down the use of
  		 * IWRITELOCK.  We are currently holding it too long.
  		 * We could also be smarter about which data pages need
  		 * to be written before the transaction is committed and
  		 * when we don't need to worry about it at all.
  		 *
  		 * if ((!S_ISDIR(ip->i_mode))

  		 *    && (tblk->flag & COMMIT_DELETE) == 0)
  		 *	filemap_write_and_wait(ip->i_mapping);

  		 */
  
  		/*
  		 * Mark inode as not dirty.  It will still be on the dirty
  		 * inode list, but we'll know not to commit it again unless
  		 * it gets marked dirty again
  		 */
  		clear_cflag(COMMIT_Dirty, ip);
  
  		/* inherit anonymous tlock(s) of inode */
  		if (jfs_ip->atlhead) {
  			lid_to_tlock(jfs_ip->atltail)->next = tblk->next;
  			tblk->next = jfs_ip->atlhead;
  			if (!tblk->last)
  				tblk->last = jfs_ip->atltail;
  			jfs_ip->atlhead = jfs_ip->atltail = 0;
  			TXN_LOCK();
  			list_del_init(&jfs_ip->anon_inode_list);
  			TXN_UNLOCK();
  		}
  
  		/*
  		 * acquire transaction lock on on-disk inode page
  		 * (become first tlock of the tblk's tlock list)
  		 */
  		if (((rc = diWrite(tid, ip))))
  			goto out;
  	}
  
  	/*

  	 *	write log records from transaction locks

  	 *
  	 * txUpdateMap() resets XAD_NEW in XAD.
  	 */
  	if ((rc = txLog(log, tblk, &cd)))
  		goto TheEnd;
  
  	/*
  	 * Ensure that inode isn't reused before
  	 * lazy commit thread finishes processing
  	 */
  	if (tblk->xflag & COMMIT_DELETE) {

  		ihold(tblk->u.ip);

  		/*
  		 * Avoid a rare deadlock
  		 *
  		 * If the inode is locked, we may be blocked in
  		 * jfs_commit_inode.  If so, we don't want the
  		 * lazy_commit thread doing the last iput() on the inode
  		 * since that may block on the locked inode.  Instead,
  		 * commit the transaction synchronously, so the last iput
  		 * will be done by the calling thread (or later)
  		 */

  		/*
  		 * I believe this code is no longer needed.  Splitting I_LOCK

  		 * into two bits, I_NEW and I_SYNC should prevent this

  		 * deadlock as well.  But since I don't have a JFS testload
  		 * to verify this, only a trivial s/I_LOCK/I_SYNC/ was done.
  		 * Joern
  		 */
  		if (tblk->u.ip->i_state & I_SYNC)

  			tblk->xflag &= ~COMMIT_LAZY;
  	}
  
  	ASSERT((!(tblk->xflag & COMMIT_DELETE)) ||
  	       ((tblk->u.ip->i_nlink == 0) &&
  		!test_cflag(COMMIT_Nolink, tblk->u.ip)));
  
  	/*

  	 *	write COMMIT log record

  	 */
  	lrd->type = cpu_to_le16(LOG_COMMIT);
  	lrd->length = 0;

  	lmLog(log, tblk, lrd, NULL);

  
  	lmGroupCommit(log, tblk);
  
  	/*

  	 *	- transaction is now committed -

  	 */
  
  	/*
  	 * force pages in careful update
  	 * (imap addressing structure update)
  	 */
  	if (flag & COMMIT_FORCE)
  		txForce(tblk);
  
  	/*

  	 *	update allocation map.

  	 *
  	 * update inode allocation map and inode:
  	 * free pager lock on memory object of inode if any.

  	 * update block allocation map.

  	 *
  	 * txUpdateMap() resets XAD_NEW in XAD.
  	 */
  	if (tblk->xflag & COMMIT_FORCE)
  		txUpdateMap(tblk);
  
  	/*

  	 *	free transaction locks and pageout/free pages

  	 */
  	txRelease(tblk);
  
  	if ((tblk->flag & tblkGC_LAZY) == 0)
  		txUnlock(tblk);
  
  
  	/*

  	 *	reset in-memory object state

  	 */
  	for (k = 0; k < cd.nip; k++) {
  		ip = cd.iplist[k];
  		jfs_ip = JFS_IP(ip);
  
  		/*
  		 * reset in-memory inode state
  		 */
  		jfs_ip->bxflag = 0;
  		jfs_ip->blid = 0;
  	}
  
        out:
  	if (rc != 0)
  		txAbort(tid, 1);
  
        TheEnd:
  	jfs_info("txCommit: tid = %d, returning %d", tid, rc);
  	return rc;
  }

  /*

   * NAME:	txLog()

   *

   * FUNCTION:	Writes AFTER log records for all lines modified
   *		by tid for segments specified by inodes in comdata.
   *		Code assumes only WRITELOCKS are recorded in lockwords.

   *
   * PARAMETERS:
   *
   * RETURN :
   */
  static int txLog(struct jfs_log * log, struct tblock * tblk, struct commit * cd)
  {
  	int rc = 0;
  	struct inode *ip;
  	lid_t lid;
  	struct tlock *tlck;
  	struct lrd *lrd = &cd->lrd;
  
  	/*
  	 * write log record(s) for each tlock of transaction,
  	 */
  	for (lid = tblk->next; lid; lid = tlck->next) {
  		tlck = lid_to_tlock(lid);
  
  		tlck->flag |= tlckLOG;
  
  		/* initialize lrd common */
  		ip = tlck->ip;
  		lrd->aggregate = cpu_to_le32(JFS_SBI(ip->i_sb)->aggregate);
  		lrd->log.redopage.fileset = cpu_to_le32(JFS_IP(ip)->fileset);
  		lrd->log.redopage.inode = cpu_to_le32(ip->i_ino);
  
  		/* write log record of page from the tlock */
  		switch (tlck->type & tlckTYPE) {
  		case tlckXTREE:
  			xtLog(log, tblk, lrd, tlck);
  			break;
  
  		case tlckDTREE:
  			dtLog(log, tblk, lrd, tlck);
  			break;
  
  		case tlckINODE:
  			diLog(log, tblk, lrd, tlck, cd);
  			break;
  
  		case tlckMAP:
  			mapLog(log, tblk, lrd, tlck);
  			break;
  
  		case tlckDATA:
  			dataLog(log, tblk, lrd, tlck);
  			break;
  
  		default:
  			jfs_err("UFO tlock:0x%p", tlck);
  		}
  	}
  
  	return rc;
  }

  /*

   *	diLog()

   *

   * function:	log inode tlock and format maplock to update bmap;

   */
  static int diLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,

  		 struct tlock * tlck, struct commit * cd)

  {
  	int rc = 0;
  	struct metapage *mp;
  	pxd_t *pxd;
  	struct pxd_lock *pxdlock;
  
  	mp = tlck->mp;
  
  	/* initialize as REDOPAGE record format */
  	lrd->log.redopage.type = cpu_to_le16(LOG_INODE);
  	lrd->log.redopage.l2linesize = cpu_to_le16(L2INODESLOTSIZE);
  
  	pxd = &lrd->log.redopage.pxd;
  
  	/*

  	 *	inode after image

  	 */
  	if (tlck->type & tlckENTRY) {
  		/* log after-image for logredo(): */
  		lrd->type = cpu_to_le16(LOG_REDOPAGE);

  		PXDaddress(pxd, mp->index);
  		PXDlength(pxd,
  			  mp->logical_size >> tblk->sb->s_blocksize_bits);
  		lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, tlck));
  
  		/* mark page as homeward bound */
  		tlck->flag |= tlckWRITEPAGE;
  	} else if (tlck->type & tlckFREE) {
  		/*

  		 *	free inode extent

  		 *
  		 * (pages of the freed inode extent have been invalidated and
  		 * a maplock for free of the extent has been formatted at
  		 * txLock() time);
  		 *
  		 * the tlock had been acquired on the inode allocation map page
  		 * (iag) that specifies the freed extent, even though the map
  		 * page is not itself logged, to prevent pageout of the map
  		 * page before the log;
  		 */
  
  		/* log LOG_NOREDOINOEXT of the freed inode extent for
  		 * logredo() to start NoRedoPage filters, and to update
  		 * imap and bmap for free of the extent;
  		 */
  		lrd->type = cpu_to_le16(LOG_NOREDOINOEXT);
  		/*
  		 * For the LOG_NOREDOINOEXT record, we need
  		 * to pass the IAG number and inode extent
  		 * index (within that IAG) from which the
  		 * the extent being released.  These have been
  		 * passed to us in the iplist[1] and iplist[2].
  		 */
  		lrd->log.noredoinoext.iagnum =
  		    cpu_to_le32((u32) (size_t) cd->iplist[1]);
  		lrd->log.noredoinoext.inoext_idx =
  		    cpu_to_le32((u32) (size_t) cd->iplist[2]);
  
  		pxdlock = (struct pxd_lock *) & tlck->lock;
  		*pxd = pxdlock->pxd;
  		lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, NULL));
  
  		/* update bmap */
  		tlck->flag |= tlckUPDATEMAP;
  
  		/* mark page as homeward bound */
  		tlck->flag |= tlckWRITEPAGE;
  	} else
  		jfs_err("diLog: UFO type tlck:0x%p", tlck);
  #ifdef  _JFS_WIP
  	/*

  	 *	alloc/free external EA extent

  	 *
  	 * a maplock for txUpdateMap() to update bPWMAP for alloc/free
  	 * of the extent has been formatted at txLock() time;
  	 */
  	else {
  		assert(tlck->type & tlckEA);
  
  		/* log LOG_UPDATEMAP for logredo() to update bmap for
  		 * alloc of new (and free of old) external EA extent;
  		 */
  		lrd->type = cpu_to_le16(LOG_UPDATEMAP);
  		pxdlock = (struct pxd_lock *) & tlck->lock;
  		nlock = pxdlock->index;
  		for (i = 0; i < nlock; i++, pxdlock++) {
  			if (pxdlock->flag & mlckALLOCPXD)
  				lrd->log.updatemap.type =
  				    cpu_to_le16(LOG_ALLOCPXD);
  			else
  				lrd->log.updatemap.type =
  				    cpu_to_le16(LOG_FREEPXD);
  			lrd->log.updatemap.nxd = cpu_to_le16(1);
  			lrd->log.updatemap.pxd = pxdlock->pxd;
  			lrd->backchain =
  			    cpu_to_le32(lmLog(log, tblk, lrd, NULL));
  		}
  
  		/* update bmap */
  		tlck->flag |= tlckUPDATEMAP;
  	}
  #endif				/* _JFS_WIP */
  
  	return rc;
  }

  /*

   *	dataLog()

   *

   * function:	log data tlock

   */
  static int dataLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
  	    struct tlock * tlck)
  {
  	struct metapage *mp;
  	pxd_t *pxd;
  
  	mp = tlck->mp;
  
  	/* initialize as REDOPAGE record format */
  	lrd->log.redopage.type = cpu_to_le16(LOG_DATA);
  	lrd->log.redopage.l2linesize = cpu_to_le16(L2DATASLOTSIZE);
  
  	pxd = &lrd->log.redopage.pxd;
  
  	/* log after-image for logredo(): */
  	lrd->type = cpu_to_le16(LOG_REDOPAGE);
  
  	if (jfs_dirtable_inline(tlck->ip)) {
  		/*
  		 * The table has been truncated, we've must have deleted
  		 * the last entry, so don't bother logging this
  		 */
  		mp->lid = 0;

  		grab_metapage(mp);
  		metapage_homeok(mp);

  		discard_metapage(mp);
  		tlck->mp = NULL;
  		return 0;
  	}
  
  	PXDaddress(pxd, mp->index);
  	PXDlength(pxd, mp->logical_size >> tblk->sb->s_blocksize_bits);
  
  	lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, tlck));
  
  	/* mark page as homeward bound */
  	tlck->flag |= tlckWRITEPAGE;
  
  	return 0;
  }

  /*

   *	dtLog()

   *

   * function:	log dtree tlock and format maplock to update bmap;

   */
  static void dtLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
  	   struct tlock * tlck)
  {
  	struct metapage *mp;
  	struct pxd_lock *pxdlock;
  	pxd_t *pxd;
  
  	mp = tlck->mp;
  
  	/* initialize as REDOPAGE/NOREDOPAGE record format */
  	lrd->log.redopage.type = cpu_to_le16(LOG_DTREE);
  	lrd->log.redopage.l2linesize = cpu_to_le16(L2DTSLOTSIZE);
  
  	pxd = &lrd->log.redopage.pxd;
  
  	if (tlck->type & tlckBTROOT)
  		lrd->log.redopage.type |= cpu_to_le16(LOG_BTROOT);
  
  	/*

  	 *	page extension via relocation: entry insertion;
  	 *	page extension in-place: entry insertion;
  	 *	new right page from page split, reinitialized in-line
  	 *	root from root page split: entry insertion;

  	 */
  	if (tlck->type & (tlckNEW | tlckEXTEND)) {
  		/* log after-image of the new page for logredo():
  		 * mark log (LOG_NEW) for logredo() to initialize
  		 * freelist and update bmap for alloc of the new page;
  		 */
  		lrd->type = cpu_to_le16(LOG_REDOPAGE);
  		if (tlck->type & tlckEXTEND)
  			lrd->log.redopage.type |= cpu_to_le16(LOG_EXTEND);
  		else
  			lrd->log.redopage.type |= cpu_to_le16(LOG_NEW);

  		PXDaddress(pxd, mp->index);
  		PXDlength(pxd,
  			  mp->logical_size >> tblk->sb->s_blocksize_bits);
  		lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, tlck));
  
  		/* format a maplock for txUpdateMap() to update bPMAP for
  		 * alloc of the new page;
  		 */
  		if (tlck->type & tlckBTROOT)
  			return;
  		tlck->flag |= tlckUPDATEMAP;
  		pxdlock = (struct pxd_lock *) & tlck->lock;
  		pxdlock->flag = mlckALLOCPXD;
  		pxdlock->pxd = *pxd;
  
  		pxdlock->index = 1;
  
  		/* mark page as homeward bound */
  		tlck->flag |= tlckWRITEPAGE;
  		return;
  	}
  
  	/*

  	 *	entry insertion/deletion,
  	 *	sibling page link update (old right page before split);

  	 */
  	if (tlck->type & (tlckENTRY | tlckRELINK)) {
  		/* log after-image for logredo(): */
  		lrd->type = cpu_to_le16(LOG_REDOPAGE);
  		PXDaddress(pxd, mp->index);
  		PXDlength(pxd,
  			  mp->logical_size >> tblk->sb->s_blocksize_bits);
  		lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, tlck));
  
  		/* mark page as homeward bound */
  		tlck->flag |= tlckWRITEPAGE;
  		return;
  	}
  
  	/*

  	 *	page deletion: page has been invalidated
  	 *	page relocation: source extent

  	 *

  	 *	a maplock for free of the page has been formatted
  	 *	at txLock() time);

  	 */
  	if (tlck->type & (tlckFREE | tlckRELOCATE)) {
  		/* log LOG_NOREDOPAGE of the deleted page for logredo()
  		 * to start NoRedoPage filter and to update bmap for free
  		 * of the deletd page
  		 */
  		lrd->type = cpu_to_le16(LOG_NOREDOPAGE);
  		pxdlock = (struct pxd_lock *) & tlck->lock;
  		*pxd = pxdlock->pxd;
  		lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, NULL));
  
  		/* a maplock for txUpdateMap() for free of the page
  		 * has been formatted at txLock() time;
  		 */
  		tlck->flag |= tlckUPDATEMAP;
  	}
  	return;
  }

  /*

   *	xtLog()

   *

   * function:	log xtree tlock and format maplock to update bmap;

   */
  static void xtLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
  	   struct tlock * tlck)
  {
  	struct inode *ip;
  	struct metapage *mp;
  	xtpage_t *p;
  	struct xtlock *xtlck;
  	struct maplock *maplock;
  	struct xdlistlock *xadlock;
  	struct pxd_lock *pxdlock;

  	pxd_t *page_pxd;

  	int next, lwm, hwm;
  
  	ip = tlck->ip;
  	mp = tlck->mp;
  
  	/* initialize as REDOPAGE/NOREDOPAGE record format */
  	lrd->log.redopage.type = cpu_to_le16(LOG_XTREE);
  	lrd->log.redopage.l2linesize = cpu_to_le16(L2XTSLOTSIZE);

  	page_pxd = &lrd->log.redopage.pxd;

  
  	if (tlck->type & tlckBTROOT) {
  		lrd->log.redopage.type |= cpu_to_le16(LOG_BTROOT);
  		p = &JFS_IP(ip)->i_xtroot;
  		if (S_ISDIR(ip->i_mode))
  			lrd->log.redopage.type |=
  			    cpu_to_le16(LOG_DIR_XTREE);
  	} else
  		p = (xtpage_t *) mp->data;
  	next = le16_to_cpu(p->header.nextindex);
  
  	xtlck = (struct xtlock *) & tlck->lock;
  
  	maplock = (struct maplock *) & tlck->lock;
  	xadlock = (struct xdlistlock *) maplock;
  
  	/*

  	 *	entry insertion/extension;
  	 *	sibling page link update (old right page before split);

  	 */
  	if (tlck->type & (tlckNEW | tlckGROW | tlckRELINK)) {
  		/* log after-image for logredo():
  		 * logredo() will update bmap for alloc of new/extended
  		 * extents (XAD_NEW|XAD_EXTEND) of XAD[lwm:next) from
  		 * after-image of XADlist;
  		 * logredo() resets (XAD_NEW|XAD_EXTEND) flag when
  		 * applying the after-image to the meta-data page.
  		 */
  		lrd->type = cpu_to_le16(LOG_REDOPAGE);

  		PXDaddress(page_pxd, mp->index);
  		PXDlength(page_pxd,

  			  mp->logical_size >> tblk->sb->s_blocksize_bits);
  		lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, tlck));
  
  		/* format a maplock for txUpdateMap() to update bPMAP
  		 * for alloc of new/extended extents of XAD[lwm:next)
  		 * from the page itself;
  		 * txUpdateMap() resets (XAD_NEW|XAD_EXTEND) flag.
  		 */
  		lwm = xtlck->lwm.offset;
  		if (lwm == 0)
  			lwm = XTPAGEMAXSLOT;
  
  		if (lwm == next)
  			goto out;
  		if (lwm > next) {
  			jfs_err("xtLog: lwm > next
  ");
  			goto out;
  		}
  		tlck->flag |= tlckUPDATEMAP;
  		xadlock->flag = mlckALLOCXADLIST;
  		xadlock->count = next - lwm;

  		if ((xadlock->count <= 4) && (tblk->xflag & COMMIT_LAZY)) {

  			int i;

  			pxd_t *pxd;

  			/*
  			 * Lazy commit may allow xtree to be modified before
  			 * txUpdateMap runs.  Copy xad into linelock to
  			 * preserve correct data.

  			 *
  			 * We can fit twice as may pxd's as xads in the lock

  			 */

  			xadlock->flag = mlckALLOCPXDLIST;
  			pxd = xadlock->xdlist = &xtlck->pxdlock;
  			for (i = 0; i < xadlock->count; i++) {
  				PXDaddress(pxd, addressXAD(&p->xad[lwm + i]));
  				PXDlength(pxd, lengthXAD(&p->xad[lwm + i]));

  				p->xad[lwm + i].flag &=
  				    ~(XAD_NEW | XAD_EXTENDED);

  				pxd++;
  			}

  		} else {
  			/*
  			 * xdlist will point to into inode's xtree, ensure
  			 * that transaction is not committed lazily.
  			 */

  			xadlock->flag = mlckALLOCXADLIST;

  			xadlock->xdlist = &p->xad[lwm];
  			tblk->xflag &= ~COMMIT_LAZY;
  		}
  		jfs_info("xtLog: alloc ip:0x%p mp:0x%p tlck:0x%p lwm:%d "
  			 "count:%d", tlck->ip, mp, tlck, lwm, xadlock->count);
  
  		maplock->index = 1;
  
  	      out:
  		/* mark page as homeward bound */
  		tlck->flag |= tlckWRITEPAGE;
  
  		return;
  	}
  
  	/*

  	 *	page deletion: file deletion/truncation (ref. xtTruncate())

  	 *
  	 * (page will be invalidated after log is written and bmap
  	 * is updated from the page);
  	 */
  	if (tlck->type & tlckFREE) {
  		/* LOG_NOREDOPAGE log for NoRedoPage filter:
  		 * if page free from file delete, NoRedoFile filter from
  		 * inode image of zero link count will subsume NoRedoPage
  		 * filters for each page;
  		 * if page free from file truncattion, write NoRedoPage
  		 * filter;
  		 *
  		 * upadte of block allocation map for the page itself:
  		 * if page free from deletion and truncation, LOG_UPDATEMAP
  		 * log for the page itself is generated from processing
  		 * its parent page xad entries;
  		 */
  		/* if page free from file truncation, log LOG_NOREDOPAGE
  		 * of the deleted page for logredo() to start NoRedoPage
  		 * filter for the page;
  		 */
  		if (tblk->xflag & COMMIT_TRUNCATE) {
  			/* write NOREDOPAGE for the page */
  			lrd->type = cpu_to_le16(LOG_NOREDOPAGE);

  			PXDaddress(page_pxd, mp->index);
  			PXDlength(page_pxd,

  				  mp->logical_size >> tblk->sb->
  				  s_blocksize_bits);
  			lrd->backchain =
  			    cpu_to_le32(lmLog(log, tblk, lrd, NULL));
  
  			if (tlck->type & tlckBTROOT) {
  				/* Empty xtree must be logged */
  				lrd->type = cpu_to_le16(LOG_REDOPAGE);
  				lrd->backchain =
  				    cpu_to_le32(lmLog(log, tblk, lrd, tlck));
  			}
  		}
  
  		/* init LOG_UPDATEMAP of the freed extents
  		 * XAD[XTENTRYSTART:hwm) from the deleted page itself
  		 * for logredo() to update bmap;
  		 */
  		lrd->type = cpu_to_le16(LOG_UPDATEMAP);
  		lrd->log.updatemap.type = cpu_to_le16(LOG_FREEXADLIST);
  		xtlck = (struct xtlock *) & tlck->lock;
  		hwm = xtlck->hwm.offset;
  		lrd->log.updatemap.nxd =
  		    cpu_to_le16(hwm - XTENTRYSTART + 1);
  		/* reformat linelock for lmLog() */
  		xtlck->header.offset = XTENTRYSTART;
  		xtlck->header.length = hwm - XTENTRYSTART + 1;
  		xtlck->index = 1;
  		lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, tlck));
  
  		/* format a maplock for txUpdateMap() to update bmap
  		 * to free extents of XAD[XTENTRYSTART:hwm) from the
  		 * deleted page itself;
  		 */
  		tlck->flag |= tlckUPDATEMAP;

  		xadlock->count = hwm - XTENTRYSTART + 1;

  		if ((xadlock->count <= 4) && (tblk->xflag & COMMIT_LAZY)) {
  			int i;
  			pxd_t *pxd;

  			/*
  			 * Lazy commit may allow xtree to be modified before
  			 * txUpdateMap runs.  Copy xad into linelock to
  			 * preserve correct data.

  			 *
  			 * We can fit twice as may pxd's as xads in the lock

  			 */

  			xadlock->flag = mlckFREEPXDLIST;
  			pxd = xadlock->xdlist = &xtlck->pxdlock;
  			for (i = 0; i < xadlock->count; i++) {
  				PXDaddress(pxd,
  					addressXAD(&p->xad[XTENTRYSTART + i]));
  				PXDlength(pxd,
  					lengthXAD(&p->xad[XTENTRYSTART + i]));
  				pxd++;
  			}

  		} else {
  			/*
  			 * xdlist will point to into inode's xtree, ensure
  			 * that transaction is not committed lazily.
  			 */

  			xadlock->flag = mlckFREEXADLIST;

  			xadlock->xdlist = &p->xad[XTENTRYSTART];
  			tblk->xflag &= ~COMMIT_LAZY;
  		}
  		jfs_info("xtLog: free ip:0x%p mp:0x%p count:%d lwm:2",
  			 tlck->ip, mp, xadlock->count);
  
  		maplock->index = 1;
  
  		/* mark page as invalid */
  		if (((tblk->xflag & COMMIT_PWMAP) || S_ISDIR(ip->i_mode))
  		    && !(tlck->type & tlckBTROOT))
  			tlck->flag |= tlckFREEPAGE;
  		/*
  		   else (tblk->xflag & COMMIT_PMAP)
  		   ? release the page;
  		 */
  		return;
  	}
  
  	/*

  	 *	page/entry truncation: file truncation (ref. xtTruncate())

  	 *

  	 *	|----------+------+------+---------------|
  	 *		   |      |      |
  	 *		   |      |     hwm - hwm before truncation
  	 *		   |     next - truncation point
  	 *		  lwm - lwm before truncation

  	 * header ?
  	 */
  	if (tlck->type & tlckTRUNCATE) {

  		/* This odd declaration suppresses a bogus gcc warning */
  		pxd_t pxd = pxd;	/* truncated extent of xad */

  		int twm;
  
  		/*
  		 * For truncation the entire linelock may be used, so it would
  		 * be difficult to store xad list in linelock itself.
  		 * Therefore, we'll just force transaction to be committed
  		 * synchronously, so that xtree pages won't be changed before
  		 * txUpdateMap runs.
  		 */
  		tblk->xflag &= ~COMMIT_LAZY;
  		lwm = xtlck->lwm.offset;
  		if (lwm == 0)
  			lwm = XTPAGEMAXSLOT;
  		hwm = xtlck->hwm.offset;
  		twm = xtlck->twm.offset;
  
  		/*

  		 *	write log records

  		 */
  		/* log after-image for logredo():
  		 *
  		 * logredo() will update bmap for alloc of new/extended
  		 * extents (XAD_NEW|XAD_EXTEND) of XAD[lwm:next) from
  		 * after-image of XADlist;
  		 * logredo() resets (XAD_NEW|XAD_EXTEND) flag when
  		 * applying the after-image to the meta-data page.
  		 */
  		lrd->type = cpu_to_le16(LOG_REDOPAGE);

  		PXDaddress(page_pxd, mp->index);
  		PXDlength(page_pxd,
  			  mp->logical_size >> tblk->sb->s_blocksize_bits);

  		lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, tlck));
  
  		/*
  		 * truncate entry XAD[twm == next - 1]:
  		 */
  		if (twm == next - 1) {
  			/* init LOG_UPDATEMAP for logredo() to update bmap for
  			 * free of truncated delta extent of the truncated
  			 * entry XAD[next - 1]:
  			 * (xtlck->pxdlock = truncated delta extent);
  			 */
  			pxdlock = (struct pxd_lock *) & xtlck->pxdlock;
  			/* assert(pxdlock->type & tlckTRUNCATE); */
  			lrd->type = cpu_to_le16(LOG_UPDATEMAP);
  			lrd->log.updatemap.type = cpu_to_le16(LOG_FREEPXD);
  			lrd->log.updatemap.nxd = cpu_to_le16(1);
  			lrd->log.updatemap.pxd = pxdlock->pxd;

  			pxd = pxdlock->pxd;	/* save to format maplock */

  			lrd->backchain =
  			    cpu_to_le32(lmLog(log, tblk, lrd, NULL));
  		}
  
  		/*
  		 * free entries XAD[next:hwm]:
  		 */
  		if (hwm >= next) {
  			/* init LOG_UPDATEMAP of the freed extents
  			 * XAD[next:hwm] from the deleted page itself
  			 * for logredo() to update bmap;
  			 */
  			lrd->type = cpu_to_le16(LOG_UPDATEMAP);
  			lrd->log.updatemap.type =
  			    cpu_to_le16(LOG_FREEXADLIST);
  			xtlck = (struct xtlock *) & tlck->lock;
  			hwm = xtlck->hwm.offset;
  			lrd->log.updatemap.nxd =
  			    cpu_to_le16(hwm - next + 1);
  			/* reformat linelock for lmLog() */
  			xtlck->header.offset = next;
  			xtlck->header.length = hwm - next + 1;
  			xtlck->index = 1;
  			lrd->backchain =
  			    cpu_to_le32(lmLog(log, tblk, lrd, tlck));
  		}
  
  		/*

  		 *	format maplock(s) for txUpdateMap() to update bmap

  		 */
  		maplock->index = 0;
  
  		/*
  		 * allocate entries XAD[lwm:next):
  		 */
  		if (lwm < next) {
  			/* format a maplock for txUpdateMap() to update bPMAP
  			 * for alloc of new/extended extents of XAD[lwm:next)
  			 * from the page itself;
  			 * txUpdateMap() resets (XAD_NEW|XAD_EXTEND) flag.
  			 */
  			tlck->flag |= tlckUPDATEMAP;
  			xadlock->flag = mlckALLOCXADLIST;
  			xadlock->count = next - lwm;
  			xadlock->xdlist = &p->xad[lwm];
  
  			jfs_info("xtLog: alloc ip:0x%p mp:0x%p count:%d "
  				 "lwm:%d next:%d",
  				 tlck->ip, mp, xadlock->count, lwm, next);
  			maplock->index++;
  			xadlock++;
  		}
  
  		/*
  		 * truncate entry XAD[twm == next - 1]:
  		 */
  		if (twm == next - 1) {

  			/* format a maplock for txUpdateMap() to update bmap
  			 * to free truncated delta extent of the truncated
  			 * entry XAD[next - 1];
  			 * (xtlck->pxdlock = truncated delta extent);
  			 */
  			tlck->flag |= tlckUPDATEMAP;
  			pxdlock = (struct pxd_lock *) xadlock;
  			pxdlock->flag = mlckFREEPXD;
  			pxdlock->count = 1;

  			pxdlock->pxd = pxd;

  
  			jfs_info("xtLog: truncate ip:0x%p mp:0x%p count:%d "
  				 "hwm:%d", ip, mp, pxdlock->count, hwm);
  			maplock->index++;
  			xadlock++;
  		}
  
  		/*
  		 * free entries XAD[next:hwm]:
  		 */
  		if (hwm >= next) {
  			/* format a maplock for txUpdateMap() to update bmap
  			 * to free extents of XAD[next:hwm] from thedeleted
  			 * page itself;
  			 */
  			tlck->flag |= tlckUPDATEMAP;
  			xadlock->flag = mlckFREEXADLIST;
  			xadlock->count = hwm - next + 1;
  			xadlock->xdlist = &p->xad[next];
  
  			jfs_info("xtLog: free ip:0x%p mp:0x%p count:%d "
  				 "next:%d hwm:%d",
  				 tlck->ip, mp, xadlock->count, next, hwm);
  			maplock->index++;
  		}
  
  		/* mark page as homeward bound */
  		tlck->flag |= tlckWRITEPAGE;
  	}
  	return;
  }

  /*

   *	mapLog()

   *

   * function:	log from maplock of freed data extents;

   */

  static void mapLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
  		   struct tlock * tlck)

  {
  	struct pxd_lock *pxdlock;
  	int i, nlock;
  	pxd_t *pxd;
  
  	/*

  	 *	page relocation: free the source page extent

  	 *
  	 * a maplock for txUpdateMap() for free of the page
  	 * has been formatted at txLock() time saving the src
  	 * relocated page address;
  	 */
  	if (tlck->type & tlckRELOCATE) {
  		/* log LOG_NOREDOPAGE of the old relocated page
  		 * for logredo() to start NoRedoPage filter;
  		 */
  		lrd->type = cpu_to_le16(LOG_NOREDOPAGE);
  		pxdlock = (struct pxd_lock *) & tlck->lock;
  		pxd = &lrd->log.redopage.pxd;
  		*pxd = pxdlock->pxd;
  		lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, NULL));
  
  		/* (N.B. currently, logredo() does NOT update bmap
  		 * for free of the page itself for (LOG_XTREE|LOG_NOREDOPAGE);
  		 * if page free from relocation, LOG_UPDATEMAP log is
  		 * specifically generated now for logredo()
  		 * to update bmap for free of src relocated page;
  		 * (new flag LOG_RELOCATE may be introduced which will
  		 * inform logredo() to start NORedoPage filter and also
  		 * update block allocation map at the same time, thus
  		 * avoiding an extra log write);
  		 */
  		lrd->type = cpu_to_le16(LOG_UPDATEMAP);
  		lrd->log.updatemap.type = cpu_to_le16(LOG_FREEPXD);
  		lrd->log.updatemap.nxd = cpu_to_le16(1);
  		lrd->log.updatemap.pxd = pxdlock->pxd;
  		lrd->backchain = cpu_to_le32(lmLog(log, tblk, lrd, NULL));
  
  		/* a maplock for txUpdateMap() for free of the page
  		 * has been formatted at txLock() time;
  		 */
  		tlck->flag |= tlckUPDATEMAP;
  		return;
  	}
  	/*
  
  	 * Otherwise it's not a relocate request
  	 *
  	 */
  	else {
  		/* log LOG_UPDATEMAP for logredo() to update bmap for
  		 * free of truncated/relocated delta extent of the data;
  		 * e.g.: external EA extent, relocated/truncated extent
  		 * from xtTailgate();
  		 */
  		lrd->type = cpu_to_le16(LOG_UPDATEMAP);
  		pxdlock = (struct pxd_lock *) & tlck->lock;
  		nlock = pxdlock->index;
  		for (i = 0; i < nlock; i++, pxdlock++) {
  			if (pxdlock->flag & mlckALLOCPXD)
  				lrd->log.updatemap.type =
  				    cpu_to_le16(LOG_ALLOCPXD);
  			else
  				lrd->log.updatemap.type =
  				    cpu_to_le16(LOG_FREEPXD);
  			lrd->log.updatemap.nxd = cpu_to_le16(1);
  			lrd->log.updatemap.pxd = pxdlock->pxd;
  			lrd->backchain =
  			    cpu_to_le32(lmLog(log, tblk, lrd, NULL));
  			jfs_info("mapLog: xaddr:0x%lx xlen:0x%x",
  				 (ulong) addressPXD(&pxdlock->pxd),
  				 lengthPXD(&pxdlock->pxd));
  		}
  
  		/* update bmap */
  		tlck->flag |= tlckUPDATEMAP;
  	}
  }

  /*

   *	txEA()

   *

   * function:	acquire maplock for EA/ACL extents or
   *		set COMMIT_INLINE flag;

   */
  void txEA(tid_t tid, struct inode *ip, dxd_t * oldea, dxd_t * newea)
  {
  	struct tlock *tlck = NULL;
  	struct pxd_lock *maplock = NULL, *pxdlock = NULL;
  
  	/*
  	 * format maplock for alloc of new EA extent
  	 */
  	if (newea) {
  		/* Since the newea could be a completely zeroed entry we need to
  		 * check for the two flags which indicate we should actually
  		 * commit new EA data
  		 */
  		if (newea->flag & DXD_EXTENT) {
  			tlck = txMaplock(tid, ip, tlckMAP);
  			maplock = (struct pxd_lock *) & tlck->lock;
  			pxdlock = (struct pxd_lock *) maplock;
  			pxdlock->flag = mlckALLOCPXD;
  			PXDaddress(&pxdlock->pxd, addressDXD(newea));
  			PXDlength(&pxdlock->pxd, lengthDXD(newea));
  			pxdlock++;
  			maplock->index = 1;
  		} else if (newea->flag & DXD_INLINE) {
  			tlck = NULL;
  
  			set_cflag(COMMIT_Inlineea, ip);
  		}
  	}
  
  	/*
  	 * format maplock for free of old EA extent
  	 */
  	if (!test_cflag(COMMIT_Nolink, ip) && oldea->flag & DXD_EXTENT) {
  		if (tlck == NULL) {
  			tlck = txMaplock(tid, ip, tlckMAP);
  			maplock = (struct pxd_lock *) & tlck->lock;
  			pxdlock = (struct pxd_lock *) maplock;
  			maplock->index = 0;
  		}
  		pxdlock->flag = mlckFREEPXD;
  		PXDaddress(&pxdlock->pxd, addressDXD(oldea));
  		PXDlength(&pxdlock->pxd, lengthDXD(oldea));
  		maplock->index++;
  	}
  }

  /*

   *	txForce()

   *
   * function: synchronously write pages locked by transaction

   *	     after txLog() but before txUpdateMap();

   */

  static void txForce(struct tblock * tblk)

  {
  	struct tlock *tlck;
  	lid_t lid, next;
  	struct metapage *mp;
  
  	/*
  	 * reverse the order of transaction tlocks in
  	 * careful update order of address index pages
  	 * (right to left, bottom up)
  	 */
  	tlck = lid_to_tlock(tblk->next);
  	lid = tlck->next;
  	tlck->next = 0;
  	while (lid) {
  		tlck = lid_to_tlock(lid);
  		next = tlck->next;
  		tlck->next = tblk->next;
  		tblk->next = lid;
  		lid = next;
  	}
  
  	/*
  	 * synchronously write the page, and
  	 * hold the page for txUpdateMap();
  	 */
  	for (lid = tblk->next; lid; lid = next) {
  		tlck = lid_to_tlock(lid);
  		next = tlck->next;
  
  		if ((mp = tlck->mp) != NULL &&
  		    (tlck->type & tlckBTROOT) == 0) {
  			assert(mp->xflag & COMMIT_PAGE);
  
  			if (tlck->flag & tlckWRITEPAGE) {
  				tlck->flag &= ~tlckWRITEPAGE;
  
  				/* do not release page to freelist */

  				force_metapage(mp);
  #if 0

  				/*
  				 * The "right" thing to do here is to
  				 * synchronously write the metadata.
  				 * With the current implementation this
  				 * is hard since write_metapage requires
  				 * us to kunmap & remap the page.  If we
  				 * have tlocks pointing into the metadata
  				 * pages, we don't want to do this.  I think
  				 * we can get by with synchronously writing
  				 * the pages when they are released.
  				 */

  				assert(mp->nohomeok);

  				set_bit(META_dirty, &mp->flag);
  				set_bit(META_sync, &mp->flag);

  #endif

  			}
  		}
  	}
  }

  /*

   *	txUpdateMap()

   *

   * function:	update persistent allocation map (and working map
   *		if appropriate);

   *
   * parameter:
   */
  static void txUpdateMap(struct tblock * tblk)
  {
  	struct inode *ip;
  	struct inode *ipimap;
  	lid_t lid;
  	struct tlock *tlck;
  	struct maplock *maplock;
  	struct pxd_lock pxdlock;
  	int maptype;
  	int k, nlock;
  	struct metapage *mp = NULL;
  
  	ipimap = JFS_SBI(tblk->sb)->ipimap;
  
  	maptype = (tblk->xflag & COMMIT_PMAP) ? COMMIT_PMAP : COMMIT_PWMAP;
  
  
  	/*

  	 *	update block allocation map

  	 *
  	 * update allocation state in pmap (and wmap) and
  	 * update lsn of the pmap page;
  	 */
  	/*
  	 * scan each tlock/page of transaction for block allocation/free:
  	 *
  	 * for each tlock/page of transaction, update map.
  	 *  ? are there tlock for pmap and pwmap at the same time ?
  	 */
  	for (lid = tblk->next; lid; lid = tlck->next) {
  		tlck = lid_to_tlock(lid);
  
  		if ((tlck->flag & tlckUPDATEMAP) == 0)
  			continue;
  
  		if (tlck->flag & tlckFREEPAGE) {
  			/*
  			 * Another thread may attempt to reuse freed space
  			 * immediately, so we want to get rid of the metapage
  			 * before anyone else has a chance to get it.
  			 * Lock metapage, update maps, then invalidate
  			 * the metapage.
  			 */
  			mp = tlck->mp;
  			ASSERT(mp->xflag & COMMIT_PAGE);

  			grab_metapage(mp);

  		}
  
  		/*
  		 * extent list:
  		 * . in-line PXD list:
  		 * . out-of-line XAD list:
  		 */
  		maplock = (struct maplock *) & tlck->lock;
  		nlock = maplock->index;
  
  		for (k = 0; k < nlock; k++, maplock++) {
  			/*
  			 * allocate blocks in persistent map:
  			 *
  			 * blocks have been allocated from wmap at alloc time;
  			 */
  			if (maplock->flag & mlckALLOC) {
  				txAllocPMap(ipimap, maplock, tblk);
  			}
  			/*
  			 * free blocks in persistent and working map:
  			 * blocks will be freed in pmap and then in wmap;
  			 *
  			 * ? tblock specifies the PMAP/PWMAP based upon
  			 * transaction
  			 *
  			 * free blocks in persistent map:
  			 * blocks will be freed from wmap at last reference
  			 * release of the object for regular files;
  			 *
  			 * Alway free blocks from both persistent & working
  			 * maps for directories
  			 */
  			else {	/* (maplock->flag & mlckFREE) */

  				if (tlck->flag & tlckDIRECTORY)

  					txFreeMap(ipimap, maplock,
  						  tblk, COMMIT_PWMAP);
  				else
  					txFreeMap(ipimap, maplock,
  						  tblk, maptype);
  			}
  		}
  		if (tlck->flag & tlckFREEPAGE) {
  			if (!(tblk->flag & tblkGC_LAZY)) {
  				/* This is equivalent to txRelease */
  				ASSERT(mp->lid == lid);
  				tlck->mp->lid = 0;
  			}

  			assert(mp->nohomeok == 1);
  			metapage_homeok(mp);

  			discard_metapage(mp);
  			tlck->mp = NULL;
  		}
  	}
  	/*

  	 *	update inode allocation map

  	 *
  	 * update allocation state in pmap and
  	 * update lsn of the pmap page;
  	 * update in-memory inode flag/state
  	 *
  	 * unlock mapper/write lock
  	 */
  	if (tblk->xflag & COMMIT_CREATE) {

  		diUpdatePMap(ipimap, tblk->ino, false, tblk);

  		/* update persistent block allocation map
  		 * for the allocation of inode extent;
  		 */
  		pxdlock.flag = mlckALLOCPXD;
  		pxdlock.pxd = tblk->u.ixpxd;
  		pxdlock.index = 1;
  		txAllocPMap(ipimap, (struct maplock *) & pxdlock, tblk);
  	} else if (tblk->xflag & COMMIT_DELETE) {
  		ip = tblk->u.ip;

  		diUpdatePMap(ipimap, ip->i_ino, true, tblk);

  		iput(ip);
  	}
  }

  /*

   *	txAllocPMap()

   *
   * function: allocate from persistent map;
   *
   * parameter:

   *	ipbmap	-
   *	malock	-
   *		xad list:
   *		pxd:
   *
   *	maptype -
   *		allocate from persistent map;
   *		free from persistent map;
   *		(e.g., tmp file - free from working map at releae
   *		 of last reference);
   *		free from persistent and working map;
   *
   *	lsn	- log sequence number;

   */
  static void txAllocPMap(struct inode *ip, struct maplock * maplock,
  			struct tblock * tblk)
  {
  	struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
  	struct xdlistlock *xadlistlock;
  	xad_t *xad;
  	s64 xaddr;
  	int xlen;
  	struct pxd_lock *pxdlock;
  	struct xdlistlock *pxdlistlock;
  	pxd_t *pxd;
  	int n;
  
  	/*
  	 * allocate from persistent map;
  	 */
  	if (maplock->flag & mlckALLOCXADLIST) {
  		xadlistlock = (struct xdlistlock *) maplock;
  		xad = xadlistlock->xdlist;
  		for (n = 0; n < xadlistlock->count; n++, xad++) {
  			if (xad->flag & (XAD_NEW | XAD_EXTENDED)) {
  				xaddr = addressXAD(xad);
  				xlen = lengthXAD(xad);

  				dbUpdatePMap(ipbmap, false, xaddr,

  					     (s64) xlen, tblk);
  				xad->flag &= ~(XAD_NEW | XAD_EXTENDED);
  				jfs_info("allocPMap: xaddr:0x%lx xlen:%d",
  					 (ulong) xaddr, xlen);
  			}
  		}
  	} else if (maplock->flag & mlckALLOCPXD) {
  		pxdlock = (struct pxd_lock *) maplock;
  		xaddr = addressPXD(&pxdlock->pxd);
  		xlen = lengthPXD(&pxdlock->pxd);

  		dbUpdatePMap(ipbmap, false, xaddr, (s64) xlen, tblk);

  		jfs_info("allocPMap: xaddr:0x%lx xlen:%d", (ulong) xaddr, xlen);
  	} else {		/* (maplock->flag & mlckALLOCPXDLIST) */
  
  		pxdlistlock = (struct xdlistlock *) maplock;
  		pxd = pxdlistlock->xdlist;
  		for (n = 0; n < pxdlistlock->count; n++, pxd++) {
  			xaddr = addressPXD(pxd);
  			xlen = lengthPXD(pxd);

  			dbUpdatePMap(ipbmap, false, xaddr, (s64) xlen,

  				     tblk);
  			jfs_info("allocPMap: xaddr:0x%lx xlen:%d",
  				 (ulong) xaddr, xlen);
  		}
  	}
  }

  /*

   *	txFreeMap()

   *

   * function:	free from persistent and/or working map;

   *
   * todo: optimization
   */
  void txFreeMap(struct inode *ip,
  	       struct maplock * maplock, struct tblock * tblk, int maptype)
  {
  	struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
  	struct xdlistlock *xadlistlock;
  	xad_t *xad;
  	s64 xaddr;
  	int xlen;
  	struct pxd_lock *pxdlock;
  	struct xdlistlock *pxdlistlock;
  	pxd_t *pxd;
  	int n;
  
  	jfs_info("txFreeMap: tblk:0x%p maplock:0x%p maptype:0x%x",
  		 tblk, maplock, maptype);
  
  	/*
  	 * free from persistent map;
  	 */
  	if (maptype == COMMIT_PMAP || maptype == COMMIT_PWMAP) {
  		if (maplock->flag & mlckFREEXADLIST) {
  			xadlistlock = (struct xdlistlock *) maplock;
  			xad = xadlistlock->xdlist;
  			for (n = 0; n < xadlistlock->count; n++, xad++) {
  				if (!(xad->flag & XAD_NEW)) {
  					xaddr = addressXAD(xad);
  					xlen = lengthXAD(xad);

  					dbUpdatePMap(ipbmap, true, xaddr,

  						     (s64) xlen, tblk);
  					jfs_info("freePMap: xaddr:0x%lx "
  						 "xlen:%d",
  						 (ulong) xaddr, xlen);
  				}
  			}
  		} else if (maplock->flag & mlckFREEPXD) {
  			pxdlock = (struct pxd_lock *) maplock;
  			xaddr = addressPXD(&pxdlock->pxd);
  			xlen = lengthPXD(&pxdlock->pxd);

  			dbUpdatePMap(ipbmap, true, xaddr, (s64) xlen,

  				     tblk);
  			jfs_info("freePMap: xaddr:0x%lx xlen:%d",
  				 (ulong) xaddr, xlen);
  		} else {	/* (maplock->flag & mlckALLOCPXDLIST) */
  
  			pxdlistlock = (struct xdlistlock *) maplock;
  			pxd = pxdlistlock->xdlist;
  			for (n = 0; n < pxdlistlock->count; n++, pxd++) {
  				xaddr = addressPXD(pxd);
  				xlen = lengthPXD(pxd);

  				dbUpdatePMap(ipbmap, true, xaddr,

  					     (s64) xlen, tblk);
  				jfs_info("freePMap: xaddr:0x%lx xlen:%d",
  					 (ulong) xaddr, xlen);
  			}
  		}
  	}
  
  	/*
  	 * free from working map;
  	 */
  	if (maptype == COMMIT_PWMAP || maptype == COMMIT_WMAP) {
  		if (maplock->flag & mlckFREEXADLIST) {
  			xadlistlock = (struct xdlistlock *) maplock;
  			xad = xadlistlock->xdlist;
  			for (n = 0; n < xadlistlock->count; n++, xad++) {
  				xaddr = addressXAD(xad);
  				xlen = lengthXAD(xad);
  				dbFree(ip, xaddr, (s64) xlen);
  				xad->flag = 0;
  				jfs_info("freeWMap: xaddr:0x%lx xlen:%d",
  					 (ulong) xaddr, xlen);
  			}
  		} else if (maplock->flag & mlckFREEPXD) {
  			pxdlock = (struct pxd_lock *) maplock;
  			xaddr = addressPXD(&pxdlock->pxd);
  			xlen = lengthPXD(&pxdlock->pxd);
  			dbFree(ip, xaddr, (s64) xlen);
  			jfs_info("freeWMap: xaddr:0x%lx xlen:%d",
  				 (ulong) xaddr, xlen);
  		} else {	/* (maplock->flag & mlckFREEPXDLIST) */
  
  			pxdlistlock = (struct xdlistlock *) maplock;
  			pxd = pxdlistlock->xdlist;
  			for (n = 0; n < pxdlistlock->count; n++, pxd++) {
  				xaddr = addressPXD(pxd);
  				xlen = lengthPXD(pxd);
  				dbFree(ip, xaddr, (s64) xlen);
  				jfs_info("freeWMap: xaddr:0x%lx xlen:%d",
  					 (ulong) xaddr, xlen);
  			}
  		}
  	}
  }

  /*

   *	txFreelock()

   *

   * function:	remove tlock from inode anonymous locklist

   */
  void txFreelock(struct inode *ip)
  {
  	struct jfs_inode_info *jfs_ip = JFS_IP(ip);
  	struct tlock *xtlck, *tlck;
  	lid_t xlid = 0, lid;
  
  	if (!jfs_ip->atlhead)
  		return;
  
  	TXN_LOCK();
  	xtlck = (struct tlock *) &jfs_ip->atlhead;
  
  	while ((lid = xtlck->next) != 0) {
  		tlck = lid_to_tlock(lid);
  		if (tlck->flag & tlckFREELOCK) {
  			xtlck->next = tlck->next;
  			txLockFree(lid);
  		} else {
  			xtlck = tlck;
  			xlid = lid;
  		}
  	}
  
  	if (jfs_ip->atlhead)
  		jfs_ip->atltail = xlid;
  	else {
  		jfs_ip->atltail = 0;
  		/*
  		 * If inode was on anon_list, remove it
  		 */
  		list_del_init(&jfs_ip->anon_inode_list);
  	}
  	TXN_UNLOCK();
  }

  /*

   *	txAbort()

   *
   * function: abort tx before commit;
   *
   * frees line-locks and segment locks for all
   * segments in comdata structure.
   * Optionally sets state of file-system to FM_DIRTY in super-block.
   * log age of page-frames in memory for which caller has
   * are reset to 0 (to avoid logwarap).
   */
  void txAbort(tid_t tid, int dirty)
  {
  	lid_t lid, next;
  	struct metapage *mp;
  	struct tblock *tblk = tid_to_tblock(tid);
  	struct tlock *tlck;
  
  	/*
  	 * free tlocks of the transaction
  	 */
  	for (lid = tblk->next; lid; lid = next) {
  		tlck = lid_to_tlock(lid);
  		next = tlck->next;
  		mp = tlck->mp;
  		JFS_IP(tlck->ip)->xtlid = 0;
  
  		if (mp) {
  			mp->lid = 0;
  
  			/*
  			 * reset lsn of page to avoid logwarap:
  			 *
  			 * (page may have been previously committed by another
  			 * transaction(s) but has not been paged, i.e.,
  			 * it may be on logsync list even though it has not
  			 * been logged for the current tx.)
  			 */
  			if (mp->xflag & COMMIT_PAGE && mp->lsn)
  				LogSyncRelease(mp);
  		}
  		/* insert tlock at head of freelist */
  		TXN_LOCK();
  		txLockFree(lid);
  		TXN_UNLOCK();
  	}
  
  	/* caller will free the transaction block */
  
  	tblk->next = tblk->last = 0;
  
  	/*
  	 * mark filesystem dirty
  	 */
  	if (dirty)
  		jfs_error(tblk->sb, "txAbort");
  
  	return;
  }
  
  /*

   *	txLazyCommit(void)

   *
   *	All transactions except those changing ipimap (COMMIT_FORCE) are
   *	processed by this routine.  This insures that the inode and block
   *	allocation maps are updated in order.  For synchronous transactions,
   *	let the user thread finish processing after txUpdateMap() is called.
   */
  static void txLazyCommit(struct tblock * tblk)
  {
  	struct jfs_log *log;
  
  	while (((tblk->flag & tblkGC_READY) == 0) &&
  	       ((tblk->flag & tblkGC_UNLOCKED) == 0)) {
  		/* We must have gotten ahead of the user thread
  		 */
  		jfs_info("jfs_lazycommit: tblk 0x%p not unlocked", tblk);
  		yield();
  	}
  
  	jfs_info("txLazyCommit: processing tblk 0x%p", tblk);
  
  	txUpdateMap(tblk);
  
  	log = (struct jfs_log *) JFS_SBI(tblk->sb)->log;
  
  	spin_lock_irq(&log->gclock);	// LOGGC_LOCK
  
  	tblk->flag |= tblkGC_COMMITTED;
  
  	if (tblk->flag & tblkGC_READY)
  		log->gcrtc--;
  
  	wake_up_all(&tblk->gcwait);	// LOGGC_WAKEUP
  
  	/*
  	 * Can't release log->gclock until we've tested tblk->flag
  	 */
  	if (tblk->flag & tblkGC_LAZY) {
  		spin_unlock_irq(&log->gclock);	// LOGGC_UNLOCK
  		txUnlock(tblk);
  		tblk->flag &= ~tblkGC_LAZY;
  		txEnd(tblk - TxBlock);	/* Convert back to tid */
  	} else
  		spin_unlock_irq(&log->gclock);	// LOGGC_UNLOCK
  
  	jfs_info("txLazyCommit: done: tblk = 0x%p", tblk);
  }
  
  /*

   *	jfs_lazycommit(void)

   *
   *	To be run as a kernel daemon.  If lbmIODone is called in an interrupt
   *	context, or where blocking is not wanted, this routine will process
   *	committed transactions from the unlock queue.
   */
  int jfs_lazycommit(void *arg)
  {
  	int WorkDone;
  	struct tblock *tblk;
  	unsigned long flags;
  	struct jfs_sb_info *sbi;

  	do {
  		LAZY_LOCK(flags);
  		jfs_commit_thread_waking = 0;	/* OK to wake another thread */
  		while (!list_empty(&TxAnchor.unlock_queue)) {
  			WorkDone = 0;
  			list_for_each_entry(tblk, &TxAnchor.unlock_queue,
  					    cqueue) {
  
  				sbi = JFS_SBI(tblk->sb);
  				/*
  				 * For each volume, the transactions must be
  				 * handled in order.  If another commit thread
  				 * is handling a tblk for this superblock,
  				 * skip it
  				 */
  				if (sbi->commit_state & IN_LAZYCOMMIT)
  					continue;
  
  				sbi->commit_state |= IN_LAZYCOMMIT;
  				WorkDone = 1;
  
  				/*
  				 * Remove transaction from queue
  				 */
  				list_del(&tblk->cqueue);
  
  				LAZY_UNLOCK(flags);
  				txLazyCommit(tblk);
  				LAZY_LOCK(flags);
  
  				sbi->commit_state &= ~IN_LAZYCOMMIT;
  				/*
  				 * Don't continue in the for loop.  (We can't
  				 * anyway, it's unsafe!)  We want to go back to
  				 * the beginning of the list.
  				 */
  				break;
  			}
  
  			/* If there was nothing to do, don't continue */
  			if (!WorkDone)
  				break;
  		}
  		/* In case a wakeup came while all threads were active */
  		jfs_commit_thread_waking = 0;

  		if (freezing(current)) {

  			LAZY_UNLOCK(flags);

  			try_to_freeze();

  		} else {
  			DECLARE_WAITQUEUE(wq, current);
  
  			add_wait_queue(&jfs_commit_thread_wait, &wq);
  			set_current_state(TASK_INTERRUPTIBLE);
  			LAZY_UNLOCK(flags);
  			schedule();

  			__set_current_state(TASK_RUNNING);

  			remove_wait_queue(&jfs_commit_thread_wait, &wq);
  		}

  	} while (!kthread_should_stop());

  
  	if (!list_empty(&TxAnchor.unlock_queue))
  		jfs_err("jfs_lazycommit being killed w/pending transactions!");
  	else
  		jfs_info("jfs_lazycommit being killed
  ");

  	return 0;

  }
  
  void txLazyUnlock(struct tblock * tblk)
  {
  	unsigned long flags;
  
  	LAZY_LOCK(flags);
  
  	list_add_tail(&tblk->cqueue, &TxAnchor.unlock_queue);
  	/*
  	 * Don't wake up a commit thread if there is already one servicing
  	 * this superblock, or if the last one we woke up hasn't started yet.
  	 */
  	if (!(JFS_SBI(tblk->sb)->commit_state & IN_LAZYCOMMIT) &&
  	    !jfs_commit_thread_waking) {
  		jfs_commit_thread_waking = 1;
  		wake_up(&jfs_commit_thread_wait);
  	}
  	LAZY_UNLOCK(flags);
  }
  
  static void LogSyncRelease(struct metapage * mp)
  {
  	struct jfs_log *log = mp->log;

  	assert(mp->nohomeok);

  	assert(log);

  	metapage_homeok(mp);

  }
  
  /*
   *	txQuiesce
   *
   *	Block all new transactions and push anonymous transactions to
   *	completion
   *
   *	This does almost the same thing as jfs_sync below.  We don't
   *	worry about deadlocking when jfs_tlocks_low is set, since we would
   *	expect jfs_sync to get us out of that jam.
   */
  void txQuiesce(struct super_block *sb)
  {
  	struct inode *ip;
  	struct jfs_inode_info *jfs_ip;
  	struct jfs_log *log = JFS_SBI(sb)->log;
  	tid_t tid;
  
  	set_bit(log_QUIESCE, &log->flag);
  
  	TXN_LOCK();
  restart:
  	while (!list_empty(&TxAnchor.anon_list)) {
  		jfs_ip = list_entry(TxAnchor.anon_list.next,
  				    struct jfs_inode_info,
  				    anon_inode_list);
  		ip = &jfs_ip->vfs_inode;
  
  		/*
  		 * inode will be removed from anonymous list
  		 * when it is committed
  		 */
  		TXN_UNLOCK();
  		tid = txBegin(ip->i_sb, COMMIT_INODE | COMMIT_FORCE);

  		mutex_lock(&jfs_ip->commit_mutex);

  		txCommit(tid, 1, &ip, 0);
  		txEnd(tid);

  		mutex_unlock(&jfs_ip->commit_mutex);

  		/*
  		 * Just to be safe.  I don't know how
  		 * long we can run without blocking
  		 */
  		cond_resched();
  		TXN_LOCK();
  	}
  
  	/*
  	 * If jfs_sync is running in parallel, there could be some inodes
  	 * on anon_list2.  Let's check.
  	 */
  	if (!list_empty(&TxAnchor.anon_list2)) {
  		list_splice(&TxAnchor.anon_list2, &TxAnchor.anon_list);
  		INIT_LIST_HEAD(&TxAnchor.anon_list2);
  		goto restart;
  	}
  	TXN_UNLOCK();
  
  	/*
  	 * We may need to kick off the group commit
  	 */
  	jfs_flush_journal(log, 0);
  }
  
  /*
   * txResume()
   *
   * Allows transactions to start again following txQuiesce
   */
  void txResume(struct super_block *sb)
  {
  	struct jfs_log *log = JFS_SBI(sb)->log;
  
  	clear_bit(log_QUIESCE, &log->flag);
  	TXN_WAKEUP(&log->syncwait);
  }
  
  /*

   *	jfs_sync(void)

   *
   *	To be run as a kernel daemon.  This is awakened when tlocks run low.
   *	We write any inodes that have anonymous tlocks so they will become
   *	available.
   */
  int jfs_sync(void *arg)
  {
  	struct inode *ip;
  	struct jfs_inode_info *jfs_ip;

  	tid_t tid;

  	do {
  		/*
  		 * write each inode on the anonymous inode list
  		 */
  		TXN_LOCK();
  		while (jfs_tlocks_low && !list_empty(&TxAnchor.anon_list)) {
  			jfs_ip = list_entry(TxAnchor.anon_list.next,
  					    struct jfs_inode_info,
  					    anon_inode_list);
  			ip = &jfs_ip->vfs_inode;
  
  			if (! igrab(ip)) {
  				/*
  				 * Inode is being freed
  				 */
  				list_del_init(&jfs_ip->anon_inode_list);

  			} else if (mutex_trylock(&jfs_ip->commit_mutex)) {

  				/*
  				 * inode will be removed from anonymous list
  				 * when it is committed
  				 */
  				TXN_UNLOCK();
  				tid = txBegin(ip->i_sb, COMMIT_INODE);

  				txCommit(tid, 1, &ip, 0);

  				txEnd(tid);

  				mutex_unlock(&jfs_ip->commit_mutex);

  
  				iput(ip);
  				/*
  				 * Just to be safe.  I don't know how
  				 * long we can run without blocking
  				 */
  				cond_resched();
  				TXN_LOCK();
  			} else {

  				/* We can't get the commit mutex.  It may

  				 * be held by a thread waiting for tlock's
  				 * so let's not block here.  Save it to
  				 * put back on the anon_list.
  				 */
  
  				/* Take off anon_list */
  				list_del(&jfs_ip->anon_inode_list);
  
  				/* Put on anon_list2 */
  				list_add(&jfs_ip->anon_inode_list,
  					 &TxAnchor.anon_list2);
  
  				TXN_UNLOCK();
  				iput(ip);
  				TXN_LOCK();
  			}
  		}
  		/* Add anon_list2 back to anon_list */
  		list_splice_init(&TxAnchor.anon_list2, &TxAnchor.anon_list);

  		if (freezing(current)) {

  			TXN_UNLOCK();

  			try_to_freeze();

  		} else {

  			set_current_state(TASK_INTERRUPTIBLE);
  			TXN_UNLOCK();
  			schedule();

  			__set_current_state(TASK_RUNNING);

  		}

  	} while (!kthread_should_stop());

  
  	jfs_info("jfs_sync being killed");

  	return 0;

  }
  
  #if defined(CONFIG_PROC_FS) && defined(CONFIG_JFS_DEBUG)

  static int jfs_txanchor_proc_show(struct seq_file *m, void *v)

  {

  	char *freewait;
  	char *freelockwait;
  	char *lowlockwait;
  
  	freewait =
  	    waitqueue_active(&TxAnchor.freewait) ? "active" : "empty";
  	freelockwait =
  	    waitqueue_active(&TxAnchor.freelockwait) ? "active" : "empty";
  	lowlockwait =
  	    waitqueue_active(&TxAnchor.lowlockwait) ? "active" : "empty";

  	seq_printf(m,

  		       "JFS TxAnchor
  "
  		       "============
  "
  		       "freetid = %d
  "
  		       "freewait = %s
  "
  		       "freelock = %d
  "
  		       "freelockwait = %s
  "
  		       "lowlockwait = %s
  "
  		       "tlocksInUse = %d
  "
  		       "jfs_tlocks_low = %d
  "
  		       "unlock_queue is %sempty
  ",
  		       TxAnchor.freetid,
  		       freewait,
  		       TxAnchor.freelock,
  		       freelockwait,
  		       lowlockwait,
  		       TxAnchor.tlocksInUse,
  		       jfs_tlocks_low,
  		       list_empty(&TxAnchor.unlock_queue) ? "" : "not ");

  	return 0;
  }

  static int jfs_txanchor_proc_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, jfs_txanchor_proc_show, NULL);

  }

  
  const struct file_operations jfs_txanchor_proc_fops = {
  	.owner		= THIS_MODULE,
  	.open		= jfs_txanchor_proc_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= single_release,
  };

  #endif
  
  #if defined(CONFIG_PROC_FS) && defined(CONFIG_JFS_STATISTICS)

  static int jfs_txstats_proc_show(struct seq_file *m, void *v)

  {

  	seq_printf(m,

  		       "JFS TxStats
  "
  		       "===========
  "
  		       "calls to txBegin = %d
  "
  		       "txBegin blocked by sync barrier = %d
  "
  		       "txBegin blocked by tlocks low = %d
  "
  		       "txBegin blocked by no free tid = %d
  "
  		       "calls to txBeginAnon = %d
  "
  		       "txBeginAnon blocked by sync barrier = %d
  "
  		       "txBeginAnon blocked by tlocks low = %d
  "
  		       "calls to txLockAlloc = %d
  "
  		       "tLockAlloc blocked by no free lock = %d
  ",
  		       TxStat.txBegin,
  		       TxStat.txBegin_barrier,
  		       TxStat.txBegin_lockslow,
  		       TxStat.txBegin_freetid,
  		       TxStat.txBeginAnon,
  		       TxStat.txBeginAnon_barrier,
  		       TxStat.txBeginAnon_lockslow,
  		       TxStat.txLockAlloc,
  		       TxStat.txLockAlloc_freelock);

  	return 0;
  }

  static int jfs_txstats_proc_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, jfs_txstats_proc_show, NULL);

  }

  
  const struct file_operations jfs_txstats_proc_fops = {
  	.owner		= THIS_MODULE,
  	.open		= jfs_txstats_proc_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= single_release,
  };

  #endif