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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *   Copyright (C) International Business Machines Corp., 2000-2005
  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
  */
 
 /*
  *  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();
     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 void diLog(struct jfs_log *log, struct tblock *tblk, struct lrd *lrd,
         struct tlock *tlck, struct commit *cd);
 static void 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 void 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\n",
            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.
      */
     txLog(log, tblk, &cd);
 
     /*
      * 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 void txLog(struct jfs_log *log, struct tblock *tblk, struct commit *cd)
 {
     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;
 }
 
 /*
  *  diLog()
  *
  * function:    log inode tlock and format maplock to update bmap;
  */
 static void diLog(struct jfs_log *log, struct tblock *tblk, struct lrd *lrd,
          struct tlock *tlck, struct commit *cd)
 {
     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
          * extent is 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);
     return;
 }
 
 /*
  *  dataLog()
  *
  * function:    log data tlock
  */
 static void 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;
     }
 
     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;
 }
 
 /*
  *  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) {
         pxd_t 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, "\n");
 
     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();
             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_init(&TxAnchor.anon_list2, &TxAnchor.anon_list);
         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.
                  */
 
                 /* Move from anon_list to anon_list2 */
                 list_move(&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();
         }
     } while (!kthread_should_stop());
 
     jfs_info("jfs_sync being killed");
     return 0;
 }
 
 #if defined(CONFIG_PROC_FS) && defined(CONFIG_JFS_DEBUG)
 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\n"
                "============\n"
                "freetid = %d\n"
                "freewait = %s\n"
                "freelock = %d\n"
                "freelockwait = %s\n"
                "lowlockwait = %s\n"
                "tlocksInUse = %d\n"
                "jfs_tlocks_low = %d\n"
                "unlock_queue is %sempty\n",
                TxAnchor.freetid,
                freewait,
                TxAnchor.freelock,
                freelockwait,
                lowlockwait,
                TxAnchor.tlocksInUse,
                jfs_tlocks_low,
                list_empty(&TxAnchor.unlock_queue) ? "" : "not ");
     return 0;
 }
 #endif
 
 #if defined(CONFIG_PROC_FS) && defined(CONFIG_JFS_STATISTICS)
 int jfs_txstats_proc_show(struct seq_file *m, void *v)
 {
     seq_printf(m,
                "JFS TxStats\n"
                "===========\n"
                "calls to txBegin = %d\n"
                "txBegin blocked by sync barrier = %d\n"
                "txBegin blocked by tlocks low = %d\n"
                "txBegin blocked by no free tid = %d\n"
                "calls to txBeginAnon = %d\n"
                "txBeginAnon blocked by sync barrier = %d\n"
                "txBeginAnon blocked by tlocks low = %d\n"
                "calls to txLockAlloc = %d\n"
                "tLockAlloc blocked by no free lock = %d\n",
                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;
 }
 #endif