JFS: Whitespace cleanup and remove some dead code
[linux-2.6.git] / fs / jfs / jfs_logmgr.c
1 /*
2  *   Copyright (C) International Business Machines Corp., 2000-2004
3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19
20 /*
21  *      jfs_logmgr.c: log manager
22  *
23  * for related information, see transaction manager (jfs_txnmgr.c), and
24  * recovery manager (jfs_logredo.c).
25  *
26  * note: for detail, RTFS.
27  *
28  *      log buffer manager:
29  * special purpose buffer manager supporting log i/o requirements.
30  * per log serial pageout of logpage
31  * queuing i/o requests and redrive i/o at iodone
32  * maintain current logpage buffer
33  * no caching since append only
34  * appropriate jfs buffer cache buffers as needed
35  *
36  *      group commit:
37  * transactions which wrote COMMIT records in the same in-memory
38  * log page during the pageout of previous/current log page(s) are
39  * committed together by the pageout of the page.
40  *
41  *      TBD lazy commit:
42  * transactions are committed asynchronously when the log page
43  * containing it COMMIT is paged out when it becomes full;
44  *
45  *      serialization:
46  * . a per log lock serialize log write.
47  * . a per log lock serialize group commit.
48  * . a per log lock serialize log open/close;
49  *
50  *      TBD log integrity:
51  * careful-write (ping-pong) of last logpage to recover from crash
52  * in overwrite.
53  * detection of split (out-of-order) write of physical sectors
54  * of last logpage via timestamp at end of each sector
55  * with its mirror data array at trailer).
56  *
57  *      alternatives:
58  * lsn - 64-bit monotonically increasing integer vs
59  * 32-bit lspn and page eor.
60  */
61
62 #include <linux/fs.h>
63 #include <linux/blkdev.h>
64 #include <linux/interrupt.h>
65 #include <linux/completion.h>
66 #include <linux/kthread.h>
67 #include <linux/buffer_head.h>          /* for sync_blockdev() */
68 #include <linux/bio.h>
69 #include <linux/freezer.h>
70 #include <linux/delay.h>
71 #include <linux/mutex.h>
72 #include "jfs_incore.h"
73 #include "jfs_filsys.h"
74 #include "jfs_metapage.h"
75 #include "jfs_superblock.h"
76 #include "jfs_txnmgr.h"
77 #include "jfs_debug.h"
78
79
80 /*
81  * lbuf's ready to be redriven.  Protected by log_redrive_lock (jfsIO thread)
82  */
83 static struct lbuf *log_redrive_list;
84 static DEFINE_SPINLOCK(log_redrive_lock);
85
86
87 /*
88  *      log read/write serialization (per log)
89  */
90 #define LOG_LOCK_INIT(log)      mutex_init(&(log)->loglock)
91 #define LOG_LOCK(log)           mutex_lock(&((log)->loglock))
92 #define LOG_UNLOCK(log)         mutex_unlock(&((log)->loglock))
93
94
95 /*
96  *      log group commit serialization (per log)
97  */
98
99 #define LOGGC_LOCK_INIT(log)    spin_lock_init(&(log)->gclock)
100 #define LOGGC_LOCK(log)         spin_lock_irq(&(log)->gclock)
101 #define LOGGC_UNLOCK(log)       spin_unlock_irq(&(log)->gclock)
102 #define LOGGC_WAKEUP(tblk)      wake_up_all(&(tblk)->gcwait)
103
104 /*
105  *      log sync serialization (per log)
106  */
107 #define LOGSYNC_DELTA(logsize)          min((logsize)/8, 128*LOGPSIZE)
108 #define LOGSYNC_BARRIER(logsize)        ((logsize)/4)
109 /*
110 #define LOGSYNC_DELTA(logsize)          min((logsize)/4, 256*LOGPSIZE)
111 #define LOGSYNC_BARRIER(logsize)        ((logsize)/2)
112 */
113
114
115 /*
116  *      log buffer cache synchronization
117  */
118 static DEFINE_SPINLOCK(jfsLCacheLock);
119
120 #define LCACHE_LOCK(flags)      spin_lock_irqsave(&jfsLCacheLock, flags)
121 #define LCACHE_UNLOCK(flags)    spin_unlock_irqrestore(&jfsLCacheLock, flags)
122
123 /*
124  * See __SLEEP_COND in jfs_locks.h
125  */
126 #define LCACHE_SLEEP_COND(wq, cond, flags)      \
127 do {                                            \
128         if (cond)                               \
129                 break;                          \
130         __SLEEP_COND(wq, cond, LCACHE_LOCK(flags), LCACHE_UNLOCK(flags)); \
131 } while (0)
132
133 #define LCACHE_WAKEUP(event)    wake_up(event)
134
135
136 /*
137  *      lbuf buffer cache (lCache) control
138  */
139 /* log buffer manager pageout control (cumulative, inclusive) */
140 #define lbmREAD         0x0001
141 #define lbmWRITE        0x0002  /* enqueue at tail of write queue;
142                                  * init pageout if at head of queue;
143                                  */
144 #define lbmRELEASE      0x0004  /* remove from write queue
145                                  * at completion of pageout;
146                                  * do not free/recycle it yet:
147                                  * caller will free it;
148                                  */
149 #define lbmSYNC         0x0008  /* do not return to freelist
150                                  * when removed from write queue;
151                                  */
152 #define lbmFREE         0x0010  /* return to freelist
153                                  * at completion of pageout;
154                                  * the buffer may be recycled;
155                                  */
156 #define lbmDONE         0x0020
157 #define lbmERROR        0x0040
158 #define lbmGC           0x0080  /* lbmIODone to perform post-GC processing
159                                  * of log page
160                                  */
161 #define lbmDIRECT       0x0100
162
163 /*
164  * Global list of active external journals
165  */
166 static LIST_HEAD(jfs_external_logs);
167 static struct jfs_log *dummy_log = NULL;
168 static DEFINE_MUTEX(jfs_log_mutex);
169
170 /*
171  * forward references
172  */
173 static int lmWriteRecord(struct jfs_log * log, struct tblock * tblk,
174                          struct lrd * lrd, struct tlock * tlck);
175
176 static int lmNextPage(struct jfs_log * log);
177 static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
178                            int activate);
179
180 static int open_inline_log(struct super_block *sb);
181 static int open_dummy_log(struct super_block *sb);
182 static int lbmLogInit(struct jfs_log * log);
183 static void lbmLogShutdown(struct jfs_log * log);
184 static struct lbuf *lbmAllocate(struct jfs_log * log, int);
185 static void lbmFree(struct lbuf * bp);
186 static void lbmfree(struct lbuf * bp);
187 static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp);
188 static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag, int cant_block);
189 static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag);
190 static int lbmIOWait(struct lbuf * bp, int flag);
191 static bio_end_io_t lbmIODone;
192 static void lbmStartIO(struct lbuf * bp);
193 static void lmGCwrite(struct jfs_log * log, int cant_block);
194 static int lmLogSync(struct jfs_log * log, int hard_sync);
195
196
197
198 /*
199  *      statistics
200  */
201 #ifdef CONFIG_JFS_STATISTICS
202 static struct lmStat {
203         uint commit;            /* # of commit */
204         uint pagedone;          /* # of page written */
205         uint submitted;         /* # of pages submitted */
206         uint full_page;         /* # of full pages submitted */
207         uint partial_page;      /* # of partial pages submitted */
208 } lmStat;
209 #endif
210
211
212 /*
213  * NAME:        lmLog()
214  *
215  * FUNCTION:    write a log record;
216  *
217  * PARAMETER:
218  *
219  * RETURN:      lsn - offset to the next log record to write (end-of-log);
220  *              -1  - error;
221  *
222  * note: todo: log error handler
223  */
224 int lmLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
225           struct tlock * tlck)
226 {
227         int lsn;
228         int diffp, difft;
229         struct metapage *mp = NULL;
230         unsigned long flags;
231
232         jfs_info("lmLog: log:0x%p tblk:0x%p, lrd:0x%p tlck:0x%p",
233                  log, tblk, lrd, tlck);
234
235         LOG_LOCK(log);
236
237         /* log by (out-of-transaction) JFS ? */
238         if (tblk == NULL)
239                 goto writeRecord;
240
241         /* log from page ? */
242         if (tlck == NULL ||
243             tlck->type & tlckBTROOT || (mp = tlck->mp) == NULL)
244                 goto writeRecord;
245
246         /*
247          *      initialize/update page/transaction recovery lsn
248          */
249         lsn = log->lsn;
250
251         LOGSYNC_LOCK(log, flags);
252
253         /*
254          * initialize page lsn if first log write of the page
255          */
256         if (mp->lsn == 0) {
257                 mp->log = log;
258                 mp->lsn = lsn;
259                 log->count++;
260
261                 /* insert page at tail of logsynclist */
262                 list_add_tail(&mp->synclist, &log->synclist);
263         }
264
265         /*
266          *      initialize/update lsn of tblock of the page
267          *
268          * transaction inherits oldest lsn of pages associated
269          * with allocation/deallocation of resources (their
270          * log records are used to reconstruct allocation map
271          * at recovery time: inode for inode allocation map,
272          * B+-tree index of extent descriptors for block
273          * allocation map);
274          * allocation map pages inherit transaction lsn at
275          * commit time to allow forwarding log syncpt past log
276          * records associated with allocation/deallocation of
277          * resources only after persistent map of these map pages
278          * have been updated and propagated to home.
279          */
280         /*
281          * initialize transaction lsn:
282          */
283         if (tblk->lsn == 0) {
284                 /* inherit lsn of its first page logged */
285                 tblk->lsn = mp->lsn;
286                 log->count++;
287
288                 /* insert tblock after the page on logsynclist */
289                 list_add(&tblk->synclist, &mp->synclist);
290         }
291         /*
292          * update transaction lsn:
293          */
294         else {
295                 /* inherit oldest/smallest lsn of page */
296                 logdiff(diffp, mp->lsn, log);
297                 logdiff(difft, tblk->lsn, log);
298                 if (diffp < difft) {
299                         /* update tblock lsn with page lsn */
300                         tblk->lsn = mp->lsn;
301
302                         /* move tblock after page on logsynclist */
303                         list_move(&tblk->synclist, &mp->synclist);
304                 }
305         }
306
307         LOGSYNC_UNLOCK(log, flags);
308
309         /*
310          *      write the log record
311          */
312       writeRecord:
313         lsn = lmWriteRecord(log, tblk, lrd, tlck);
314
315         /*
316          * forward log syncpt if log reached next syncpt trigger
317          */
318         logdiff(diffp, lsn, log);
319         if (diffp >= log->nextsync)
320                 lsn = lmLogSync(log, 0);
321
322         /* update end-of-log lsn */
323         log->lsn = lsn;
324
325         LOG_UNLOCK(log);
326
327         /* return end-of-log address */
328         return lsn;
329 }
330
331 /*
332  * NAME:        lmWriteRecord()
333  *
334  * FUNCTION:    move the log record to current log page
335  *
336  * PARAMETER:   cd      - commit descriptor
337  *
338  * RETURN:      end-of-log address
339  *
340  * serialization: LOG_LOCK() held on entry/exit
341  */
342 static int
343 lmWriteRecord(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
344               struct tlock * tlck)
345 {
346         int lsn = 0;            /* end-of-log address */
347         struct lbuf *bp;        /* dst log page buffer */
348         struct logpage *lp;     /* dst log page */
349         caddr_t dst;            /* destination address in log page */
350         int dstoffset;          /* end-of-log offset in log page */
351         int freespace;          /* free space in log page */
352         caddr_t p;              /* src meta-data page */
353         caddr_t src;
354         int srclen;
355         int nbytes;             /* number of bytes to move */
356         int i;
357         int len;
358         struct linelock *linelock;
359         struct lv *lv;
360         struct lvd *lvd;
361         int l2linesize;
362
363         len = 0;
364
365         /* retrieve destination log page to write */
366         bp = (struct lbuf *) log->bp;
367         lp = (struct logpage *) bp->l_ldata;
368         dstoffset = log->eor;
369
370         /* any log data to write ? */
371         if (tlck == NULL)
372                 goto moveLrd;
373
374         /*
375          *      move log record data
376          */
377         /* retrieve source meta-data page to log */
378         if (tlck->flag & tlckPAGELOCK) {
379                 p = (caddr_t) (tlck->mp->data);
380                 linelock = (struct linelock *) & tlck->lock;
381         }
382         /* retrieve source in-memory inode to log */
383         else if (tlck->flag & tlckINODELOCK) {
384                 if (tlck->type & tlckDTREE)
385                         p = (caddr_t) &JFS_IP(tlck->ip)->i_dtroot;
386                 else
387                         p = (caddr_t) &JFS_IP(tlck->ip)->i_xtroot;
388                 linelock = (struct linelock *) & tlck->lock;
389         }
390 #ifdef  _JFS_WIP
391         else if (tlck->flag & tlckINLINELOCK) {
392
393                 inlinelock = (struct inlinelock *) & tlck;
394                 p = (caddr_t) & inlinelock->pxd;
395                 linelock = (struct linelock *) & tlck;
396         }
397 #endif                          /* _JFS_WIP */
398         else {
399                 jfs_err("lmWriteRecord: UFO tlck:0x%p", tlck);
400                 return 0;       /* Probably should trap */
401         }
402         l2linesize = linelock->l2linesize;
403
404       moveData:
405         ASSERT(linelock->index <= linelock->maxcnt);
406
407         lv = linelock->lv;
408         for (i = 0; i < linelock->index; i++, lv++) {
409                 if (lv->length == 0)
410                         continue;
411
412                 /* is page full ? */
413                 if (dstoffset >= LOGPSIZE - LOGPTLRSIZE) {
414                         /* page become full: move on to next page */
415                         lmNextPage(log);
416
417                         bp = log->bp;
418                         lp = (struct logpage *) bp->l_ldata;
419                         dstoffset = LOGPHDRSIZE;
420                 }
421
422                 /*
423                  * move log vector data
424                  */
425                 src = (u8 *) p + (lv->offset << l2linesize);
426                 srclen = lv->length << l2linesize;
427                 len += srclen;
428                 while (srclen > 0) {
429                         freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
430                         nbytes = min(freespace, srclen);
431                         dst = (caddr_t) lp + dstoffset;
432                         memcpy(dst, src, nbytes);
433                         dstoffset += nbytes;
434
435                         /* is page not full ? */
436                         if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
437                                 break;
438
439                         /* page become full: move on to next page */
440                         lmNextPage(log);
441
442                         bp = (struct lbuf *) log->bp;
443                         lp = (struct logpage *) bp->l_ldata;
444                         dstoffset = LOGPHDRSIZE;
445
446                         srclen -= nbytes;
447                         src += nbytes;
448                 }
449
450                 /*
451                  * move log vector descriptor
452                  */
453                 len += 4;
454                 lvd = (struct lvd *) ((caddr_t) lp + dstoffset);
455                 lvd->offset = cpu_to_le16(lv->offset);
456                 lvd->length = cpu_to_le16(lv->length);
457                 dstoffset += 4;
458                 jfs_info("lmWriteRecord: lv offset:%d length:%d",
459                          lv->offset, lv->length);
460         }
461
462         if ((i = linelock->next)) {
463                 linelock = (struct linelock *) lid_to_tlock(i);
464                 goto moveData;
465         }
466
467         /*
468          *      move log record descriptor
469          */
470       moveLrd:
471         lrd->length = cpu_to_le16(len);
472
473         src = (caddr_t) lrd;
474         srclen = LOGRDSIZE;
475
476         while (srclen > 0) {
477                 freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
478                 nbytes = min(freespace, srclen);
479                 dst = (caddr_t) lp + dstoffset;
480                 memcpy(dst, src, nbytes);
481
482                 dstoffset += nbytes;
483                 srclen -= nbytes;
484
485                 /* are there more to move than freespace of page ? */
486                 if (srclen)
487                         goto pageFull;
488
489                 /*
490                  * end of log record descriptor
491                  */
492
493                 /* update last log record eor */
494                 log->eor = dstoffset;
495                 bp->l_eor = dstoffset;
496                 lsn = (log->page << L2LOGPSIZE) + dstoffset;
497
498                 if (lrd->type & cpu_to_le16(LOG_COMMIT)) {
499                         tblk->clsn = lsn;
500                         jfs_info("wr: tclsn:0x%x, beor:0x%x", tblk->clsn,
501                                  bp->l_eor);
502
503                         INCREMENT(lmStat.commit);       /* # of commit */
504
505                         /*
506                          * enqueue tblock for group commit:
507                          *
508                          * enqueue tblock of non-trivial/synchronous COMMIT
509                          * at tail of group commit queue
510                          * (trivial/asynchronous COMMITs are ignored by
511                          * group commit.)
512                          */
513                         LOGGC_LOCK(log);
514
515                         /* init tblock gc state */
516                         tblk->flag = tblkGC_QUEUE;
517                         tblk->bp = log->bp;
518                         tblk->pn = log->page;
519                         tblk->eor = log->eor;
520
521                         /* enqueue transaction to commit queue */
522                         list_add_tail(&tblk->cqueue, &log->cqueue);
523
524                         LOGGC_UNLOCK(log);
525                 }
526
527                 jfs_info("lmWriteRecord: lrd:0x%04x bp:0x%p pn:%d eor:0x%x",
528                         le16_to_cpu(lrd->type), log->bp, log->page, dstoffset);
529
530                 /* page not full ? */
531                 if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
532                         return lsn;
533
534               pageFull:
535                 /* page become full: move on to next page */
536                 lmNextPage(log);
537
538                 bp = (struct lbuf *) log->bp;
539                 lp = (struct logpage *) bp->l_ldata;
540                 dstoffset = LOGPHDRSIZE;
541                 src += nbytes;
542         }
543
544         return lsn;
545 }
546
547
548 /*
549  * NAME:        lmNextPage()
550  *
551  * FUNCTION:    write current page and allocate next page.
552  *
553  * PARAMETER:   log
554  *
555  * RETURN:      0
556  *
557  * serialization: LOG_LOCK() held on entry/exit
558  */
559 static int lmNextPage(struct jfs_log * log)
560 {
561         struct logpage *lp;
562         int lspn;               /* log sequence page number */
563         int pn;                 /* current page number */
564         struct lbuf *bp;
565         struct lbuf *nextbp;
566         struct tblock *tblk;
567
568         /* get current log page number and log sequence page number */
569         pn = log->page;
570         bp = log->bp;
571         lp = (struct logpage *) bp->l_ldata;
572         lspn = le32_to_cpu(lp->h.page);
573
574         LOGGC_LOCK(log);
575
576         /*
577          *      write or queue the full page at the tail of write queue
578          */
579         /* get the tail tblk on commit queue */
580         if (list_empty(&log->cqueue))
581                 tblk = NULL;
582         else
583                 tblk = list_entry(log->cqueue.prev, struct tblock, cqueue);
584
585         /* every tblk who has COMMIT record on the current page,
586          * and has not been committed, must be on commit queue
587          * since tblk is queued at commit queueu at the time
588          * of writing its COMMIT record on the page before
589          * page becomes full (even though the tblk thread
590          * who wrote COMMIT record may have been suspended
591          * currently);
592          */
593
594         /* is page bound with outstanding tail tblk ? */
595         if (tblk && tblk->pn == pn) {
596                 /* mark tblk for end-of-page */
597                 tblk->flag |= tblkGC_EOP;
598
599                 if (log->cflag & logGC_PAGEOUT) {
600                         /* if page is not already on write queue,
601                          * just enqueue (no lbmWRITE to prevent redrive)
602                          * buffer to wqueue to ensure correct serial order
603                          * of the pages since log pages will be added
604                          * continuously
605                          */
606                         if (bp->l_wqnext == NULL)
607                                 lbmWrite(log, bp, 0, 0);
608                 } else {
609                         /*
610                          * No current GC leader, initiate group commit
611                          */
612                         log->cflag |= logGC_PAGEOUT;
613                         lmGCwrite(log, 0);
614                 }
615         }
616         /* page is not bound with outstanding tblk:
617          * init write or mark it to be redriven (lbmWRITE)
618          */
619         else {
620                 /* finalize the page */
621                 bp->l_ceor = bp->l_eor;
622                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
623                 lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE, 0);
624         }
625         LOGGC_UNLOCK(log);
626
627         /*
628          *      allocate/initialize next page
629          */
630         /* if log wraps, the first data page of log is 2
631          * (0 never used, 1 is superblock).
632          */
633         log->page = (pn == log->size - 1) ? 2 : pn + 1;
634         log->eor = LOGPHDRSIZE; /* ? valid page empty/full at logRedo() */
635
636         /* allocate/initialize next log page buffer */
637         nextbp = lbmAllocate(log, log->page);
638         nextbp->l_eor = log->eor;
639         log->bp = nextbp;
640
641         /* initialize next log page */
642         lp = (struct logpage *) nextbp->l_ldata;
643         lp->h.page = lp->t.page = cpu_to_le32(lspn + 1);
644         lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
645
646         return 0;
647 }
648
649
650 /*
651  * NAME:        lmGroupCommit()
652  *
653  * FUNCTION:    group commit
654  *      initiate pageout of the pages with COMMIT in the order of
655  *      page number - redrive pageout of the page at the head of
656  *      pageout queue until full page has been written.
657  *
658  * RETURN:
659  *
660  * NOTE:
661  *      LOGGC_LOCK serializes log group commit queue, and
662  *      transaction blocks on the commit queue.
663  *      N.B. LOG_LOCK is NOT held during lmGroupCommit().
664  */
665 int lmGroupCommit(struct jfs_log * log, struct tblock * tblk)
666 {
667         int rc = 0;
668
669         LOGGC_LOCK(log);
670
671         /* group committed already ? */
672         if (tblk->flag & tblkGC_COMMITTED) {
673                 if (tblk->flag & tblkGC_ERROR)
674                         rc = -EIO;
675
676                 LOGGC_UNLOCK(log);
677                 return rc;
678         }
679         jfs_info("lmGroup Commit: tblk = 0x%p, gcrtc = %d", tblk, log->gcrtc);
680
681         if (tblk->xflag & COMMIT_LAZY)
682                 tblk->flag |= tblkGC_LAZY;
683
684         if ((!(log->cflag & logGC_PAGEOUT)) && (!list_empty(&log->cqueue)) &&
685             (!(tblk->xflag & COMMIT_LAZY) || test_bit(log_FLUSH, &log->flag)
686              || jfs_tlocks_low)) {
687                 /*
688                  * No pageout in progress
689                  *
690                  * start group commit as its group leader.
691                  */
692                 log->cflag |= logGC_PAGEOUT;
693
694                 lmGCwrite(log, 0);
695         }
696
697         if (tblk->xflag & COMMIT_LAZY) {
698                 /*
699                  * Lazy transactions can leave now
700                  */
701                 LOGGC_UNLOCK(log);
702                 return 0;
703         }
704
705         /* lmGCwrite gives up LOGGC_LOCK, check again */
706
707         if (tblk->flag & tblkGC_COMMITTED) {
708                 if (tblk->flag & tblkGC_ERROR)
709                         rc = -EIO;
710
711                 LOGGC_UNLOCK(log);
712                 return rc;
713         }
714
715         /* upcount transaction waiting for completion
716          */
717         log->gcrtc++;
718         tblk->flag |= tblkGC_READY;
719
720         __SLEEP_COND(tblk->gcwait, (tblk->flag & tblkGC_COMMITTED),
721                      LOGGC_LOCK(log), LOGGC_UNLOCK(log));
722
723         /* removed from commit queue */
724         if (tblk->flag & tblkGC_ERROR)
725                 rc = -EIO;
726
727         LOGGC_UNLOCK(log);
728         return rc;
729 }
730
731 /*
732  * NAME:        lmGCwrite()
733  *
734  * FUNCTION:    group commit write
735  *      initiate write of log page, building a group of all transactions
736  *      with commit records on that page.
737  *
738  * RETURN:      None
739  *
740  * NOTE:
741  *      LOGGC_LOCK must be held by caller.
742  *      N.B. LOG_LOCK is NOT held during lmGroupCommit().
743  */
744 static void lmGCwrite(struct jfs_log * log, int cant_write)
745 {
746         struct lbuf *bp;
747         struct logpage *lp;
748         int gcpn;               /* group commit page number */
749         struct tblock *tblk;
750         struct tblock *xtblk = NULL;
751
752         /*
753          * build the commit group of a log page
754          *
755          * scan commit queue and make a commit group of all
756          * transactions with COMMIT records on the same log page.
757          */
758         /* get the head tblk on the commit queue */
759         gcpn = list_entry(log->cqueue.next, struct tblock, cqueue)->pn;
760
761         list_for_each_entry(tblk, &log->cqueue, cqueue) {
762                 if (tblk->pn != gcpn)
763                         break;
764
765                 xtblk = tblk;
766
767                 /* state transition: (QUEUE, READY) -> COMMIT */
768                 tblk->flag |= tblkGC_COMMIT;
769         }
770         tblk = xtblk;           /* last tblk of the page */
771
772         /*
773          * pageout to commit transactions on the log page.
774          */
775         bp = (struct lbuf *) tblk->bp;
776         lp = (struct logpage *) bp->l_ldata;
777         /* is page already full ? */
778         if (tblk->flag & tblkGC_EOP) {
779                 /* mark page to free at end of group commit of the page */
780                 tblk->flag &= ~tblkGC_EOP;
781                 tblk->flag |= tblkGC_FREE;
782                 bp->l_ceor = bp->l_eor;
783                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
784                 lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmGC,
785                          cant_write);
786                 INCREMENT(lmStat.full_page);
787         }
788         /* page is not yet full */
789         else {
790                 bp->l_ceor = tblk->eor; /* ? bp->l_ceor = bp->l_eor; */
791                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
792                 lbmWrite(log, bp, lbmWRITE | lbmGC, cant_write);
793                 INCREMENT(lmStat.partial_page);
794         }
795 }
796
797 /*
798  * NAME:        lmPostGC()
799  *
800  * FUNCTION:    group commit post-processing
801  *      Processes transactions after their commit records have been written
802  *      to disk, redriving log I/O if necessary.
803  *
804  * RETURN:      None
805  *
806  * NOTE:
807  *      This routine is called a interrupt time by lbmIODone
808  */
809 static void lmPostGC(struct lbuf * bp)
810 {
811         unsigned long flags;
812         struct jfs_log *log = bp->l_log;
813         struct logpage *lp;
814         struct tblock *tblk, *temp;
815
816         //LOGGC_LOCK(log);
817         spin_lock_irqsave(&log->gclock, flags);
818         /*
819          * current pageout of group commit completed.
820          *
821          * remove/wakeup transactions from commit queue who were
822          * group committed with the current log page
823          */
824         list_for_each_entry_safe(tblk, temp, &log->cqueue, cqueue) {
825                 if (!(tblk->flag & tblkGC_COMMIT))
826                         break;
827                 /* if transaction was marked GC_COMMIT then
828                  * it has been shipped in the current pageout
829                  * and made it to disk - it is committed.
830                  */
831
832                 if (bp->l_flag & lbmERROR)
833                         tblk->flag |= tblkGC_ERROR;
834
835                 /* remove it from the commit queue */
836                 list_del(&tblk->cqueue);
837                 tblk->flag &= ~tblkGC_QUEUE;
838
839                 if (tblk == log->flush_tblk) {
840                         /* we can stop flushing the log now */
841                         clear_bit(log_FLUSH, &log->flag);
842                         log->flush_tblk = NULL;
843                 }
844
845                 jfs_info("lmPostGC: tblk = 0x%p, flag = 0x%x", tblk,
846                          tblk->flag);
847
848                 if (!(tblk->xflag & COMMIT_FORCE))
849                         /*
850                          * Hand tblk over to lazy commit thread
851                          */
852                         txLazyUnlock(tblk);
853                 else {
854                         /* state transition: COMMIT -> COMMITTED */
855                         tblk->flag |= tblkGC_COMMITTED;
856
857                         if (tblk->flag & tblkGC_READY)
858                                 log->gcrtc--;
859
860                         LOGGC_WAKEUP(tblk);
861                 }
862
863                 /* was page full before pageout ?
864                  * (and this is the last tblk bound with the page)
865                  */
866                 if (tblk->flag & tblkGC_FREE)
867                         lbmFree(bp);
868                 /* did page become full after pageout ?
869                  * (and this is the last tblk bound with the page)
870                  */
871                 else if (tblk->flag & tblkGC_EOP) {
872                         /* finalize the page */
873                         lp = (struct logpage *) bp->l_ldata;
874                         bp->l_ceor = bp->l_eor;
875                         lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
876                         jfs_info("lmPostGC: calling lbmWrite");
877                         lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE,
878                                  1);
879                 }
880
881         }
882
883         /* are there any transactions who have entered lnGroupCommit()
884          * (whose COMMITs are after that of the last log page written.
885          * They are waiting for new group commit (above at (SLEEP 1))
886          * or lazy transactions are on a full (queued) log page,
887          * select the latest ready transaction as new group leader and
888          * wake her up to lead her group.
889          */
890         if ((!list_empty(&log->cqueue)) &&
891             ((log->gcrtc > 0) || (tblk->bp->l_wqnext != NULL) ||
892              test_bit(log_FLUSH, &log->flag) || jfs_tlocks_low))
893                 /*
894                  * Call lmGCwrite with new group leader
895                  */
896                 lmGCwrite(log, 1);
897
898         /* no transaction are ready yet (transactions are only just
899          * queued (GC_QUEUE) and not entered for group commit yet).
900          * the first transaction entering group commit
901          * will elect herself as new group leader.
902          */
903         else
904                 log->cflag &= ~logGC_PAGEOUT;
905
906         //LOGGC_UNLOCK(log);
907         spin_unlock_irqrestore(&log->gclock, flags);
908         return;
909 }
910
911 /*
912  * NAME:        lmLogSync()
913  *
914  * FUNCTION:    write log SYNCPT record for specified log
915  *      if new sync address is available
916  *      (normally the case if sync() is executed by back-ground
917  *      process).
918  *      calculate new value of i_nextsync which determines when
919  *      this code is called again.
920  *
921  * PARAMETERS:  log     - log structure
922  *              hard_sync - 1 to force all metadata to be written
923  *
924  * RETURN:      0
925  *
926  * serialization: LOG_LOCK() held on entry/exit
927  */
928 static int lmLogSync(struct jfs_log * log, int hard_sync)
929 {
930         int logsize;
931         int written;            /* written since last syncpt */
932         int free;               /* free space left available */
933         int delta;              /* additional delta to write normally */
934         int more;               /* additional write granted */
935         struct lrd lrd;
936         int lsn;
937         struct logsyncblk *lp;
938         struct jfs_sb_info *sbi;
939         unsigned long flags;
940
941         /* push dirty metapages out to disk */
942         if (hard_sync)
943                 list_for_each_entry(sbi, &log->sb_list, log_list) {
944                         filemap_fdatawrite(sbi->ipbmap->i_mapping);
945                         filemap_fdatawrite(sbi->ipimap->i_mapping);
946                         filemap_fdatawrite(sbi->direct_inode->i_mapping);
947                 }
948         else
949                 list_for_each_entry(sbi, &log->sb_list, log_list) {
950                         filemap_flush(sbi->ipbmap->i_mapping);
951                         filemap_flush(sbi->ipimap->i_mapping);
952                         filemap_flush(sbi->direct_inode->i_mapping);
953                 }
954
955         /*
956          *      forward syncpt
957          */
958         /* if last sync is same as last syncpt,
959          * invoke sync point forward processing to update sync.
960          */
961
962         if (log->sync == log->syncpt) {
963                 LOGSYNC_LOCK(log, flags);
964                 if (list_empty(&log->synclist))
965                         log->sync = log->lsn;
966                 else {
967                         lp = list_entry(log->synclist.next,
968                                         struct logsyncblk, synclist);
969                         log->sync = lp->lsn;
970                 }
971                 LOGSYNC_UNLOCK(log, flags);
972
973         }
974
975         /* if sync is different from last syncpt,
976          * write a SYNCPT record with syncpt = sync.
977          * reset syncpt = sync
978          */
979         if (log->sync != log->syncpt) {
980                 lrd.logtid = 0;
981                 lrd.backchain = 0;
982                 lrd.type = cpu_to_le16(LOG_SYNCPT);
983                 lrd.length = 0;
984                 lrd.log.syncpt.sync = cpu_to_le32(log->sync);
985                 lsn = lmWriteRecord(log, NULL, &lrd, NULL);
986
987                 log->syncpt = log->sync;
988         } else
989                 lsn = log->lsn;
990
991         /*
992          *      setup next syncpt trigger (SWAG)
993          */
994         logsize = log->logsize;
995
996         logdiff(written, lsn, log);
997         free = logsize - written;
998         delta = LOGSYNC_DELTA(logsize);
999         more = min(free / 2, delta);
1000         if (more < 2 * LOGPSIZE) {
1001                 jfs_warn("\n ... Log Wrap ... Log Wrap ... Log Wrap ...\n");
1002                 /*
1003                  *      log wrapping
1004                  *
1005                  * option 1 - panic ? No.!
1006                  * option 2 - shutdown file systems
1007                  *            associated with log ?
1008                  * option 3 - extend log ?
1009                  */
1010                 /*
1011                  * option 4 - second chance
1012                  *
1013                  * mark log wrapped, and continue.
1014                  * when all active transactions are completed,
1015                  * mark log vaild for recovery.
1016                  * if crashed during invalid state, log state
1017                  * implies invald log, forcing fsck().
1018                  */
1019                 /* mark log state log wrap in log superblock */
1020                 /* log->state = LOGWRAP; */
1021
1022                 /* reset sync point computation */
1023                 log->syncpt = log->sync = lsn;
1024                 log->nextsync = delta;
1025         } else
1026                 /* next syncpt trigger = written + more */
1027                 log->nextsync = written + more;
1028
1029         /* if number of bytes written from last sync point is more
1030          * than 1/4 of the log size, stop new transactions from
1031          * starting until all current transactions are completed
1032          * by setting syncbarrier flag.
1033          */
1034         if (!test_bit(log_SYNCBARRIER, &log->flag) &&
1035             (written > LOGSYNC_BARRIER(logsize)) && log->active) {
1036                 set_bit(log_SYNCBARRIER, &log->flag);
1037                 jfs_info("log barrier on: lsn=0x%x syncpt=0x%x", lsn,
1038                          log->syncpt);
1039                 /*
1040                  * We may have to initiate group commit
1041                  */
1042                 jfs_flush_journal(log, 0);
1043         }
1044
1045         return lsn;
1046 }
1047
1048 /*
1049  * NAME:        jfs_syncpt
1050  *
1051  * FUNCTION:    write log SYNCPT record for specified log
1052  *
1053  * PARAMETERS:  log       - log structure
1054  *              hard_sync - set to 1 to force metadata to be written
1055  */
1056 void jfs_syncpt(struct jfs_log *log, int hard_sync)
1057 {       LOG_LOCK(log);
1058         lmLogSync(log, hard_sync);
1059         LOG_UNLOCK(log);
1060 }
1061
1062 /*
1063  * NAME:        lmLogOpen()
1064  *
1065  * FUNCTION:    open the log on first open;
1066  *      insert filesystem in the active list of the log.
1067  *
1068  * PARAMETER:   ipmnt   - file system mount inode
1069  *              iplog   - log inode (out)
1070  *
1071  * RETURN:
1072  *
1073  * serialization:
1074  */
1075 int lmLogOpen(struct super_block *sb)
1076 {
1077         int rc;
1078         struct block_device *bdev;
1079         struct jfs_log *log;
1080         struct jfs_sb_info *sbi = JFS_SBI(sb);
1081
1082         if (sbi->flag & JFS_NOINTEGRITY)
1083                 return open_dummy_log(sb);
1084
1085         if (sbi->mntflag & JFS_INLINELOG)
1086                 return open_inline_log(sb);
1087
1088         mutex_lock(&jfs_log_mutex);
1089         list_for_each_entry(log, &jfs_external_logs, journal_list) {
1090                 if (log->bdev->bd_dev == sbi->logdev) {
1091                         if (memcmp(log->uuid, sbi->loguuid,
1092                                    sizeof(log->uuid))) {
1093                                 jfs_warn("wrong uuid on JFS journal\n");
1094                                 mutex_unlock(&jfs_log_mutex);
1095                                 return -EINVAL;
1096                         }
1097                         /*
1098                          * add file system to log active file system list
1099                          */
1100                         if ((rc = lmLogFileSystem(log, sbi, 1))) {
1101                                 mutex_unlock(&jfs_log_mutex);
1102                                 return rc;
1103                         }
1104                         goto journal_found;
1105                 }
1106         }
1107
1108         if (!(log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL))) {
1109                 mutex_unlock(&jfs_log_mutex);
1110                 return -ENOMEM;
1111         }
1112         INIT_LIST_HEAD(&log->sb_list);
1113         init_waitqueue_head(&log->syncwait);
1114
1115         /*
1116          *      external log as separate logical volume
1117          *
1118          * file systems to log may have n-to-1 relationship;
1119          */
1120
1121         bdev = open_by_devnum(sbi->logdev, FMODE_READ|FMODE_WRITE);
1122         if (IS_ERR(bdev)) {
1123                 rc = -PTR_ERR(bdev);
1124                 goto free;
1125         }
1126
1127         if ((rc = bd_claim(bdev, log))) {
1128                 goto close;
1129         }
1130
1131         log->bdev = bdev;
1132         memcpy(log->uuid, sbi->loguuid, sizeof(log->uuid));
1133
1134         /*
1135          * initialize log:
1136          */
1137         if ((rc = lmLogInit(log)))
1138                 goto unclaim;
1139
1140         list_add(&log->journal_list, &jfs_external_logs);
1141
1142         /*
1143          * add file system to log active file system list
1144          */
1145         if ((rc = lmLogFileSystem(log, sbi, 1)))
1146                 goto shutdown;
1147
1148 journal_found:
1149         LOG_LOCK(log);
1150         list_add(&sbi->log_list, &log->sb_list);
1151         sbi->log = log;
1152         LOG_UNLOCK(log);
1153
1154         mutex_unlock(&jfs_log_mutex);
1155         return 0;
1156
1157         /*
1158          *      unwind on error
1159          */
1160       shutdown:         /* unwind lbmLogInit() */
1161         list_del(&log->journal_list);
1162         lbmLogShutdown(log);
1163
1164       unclaim:
1165         bd_release(bdev);
1166
1167       close:            /* close external log device */
1168         blkdev_put(bdev);
1169
1170       free:             /* free log descriptor */
1171         mutex_unlock(&jfs_log_mutex);
1172         kfree(log);
1173
1174         jfs_warn("lmLogOpen: exit(%d)", rc);
1175         return rc;
1176 }
1177
1178 static int open_inline_log(struct super_block *sb)
1179 {
1180         struct jfs_log *log;
1181         int rc;
1182
1183         if (!(log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL)))
1184                 return -ENOMEM;
1185         INIT_LIST_HEAD(&log->sb_list);
1186         init_waitqueue_head(&log->syncwait);
1187
1188         set_bit(log_INLINELOG, &log->flag);
1189         log->bdev = sb->s_bdev;
1190         log->base = addressPXD(&JFS_SBI(sb)->logpxd);
1191         log->size = lengthPXD(&JFS_SBI(sb)->logpxd) >>
1192             (L2LOGPSIZE - sb->s_blocksize_bits);
1193         log->l2bsize = sb->s_blocksize_bits;
1194         ASSERT(L2LOGPSIZE >= sb->s_blocksize_bits);
1195
1196         /*
1197          * initialize log.
1198          */
1199         if ((rc = lmLogInit(log))) {
1200                 kfree(log);
1201                 jfs_warn("lmLogOpen: exit(%d)", rc);
1202                 return rc;
1203         }
1204
1205         list_add(&JFS_SBI(sb)->log_list, &log->sb_list);
1206         JFS_SBI(sb)->log = log;
1207
1208         return rc;
1209 }
1210
1211 static int open_dummy_log(struct super_block *sb)
1212 {
1213         int rc;
1214
1215         mutex_lock(&jfs_log_mutex);
1216         if (!dummy_log) {
1217                 dummy_log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL);
1218                 if (!dummy_log) {
1219                         mutex_unlock(&jfs_log_mutex);
1220                         return -ENOMEM;
1221                 }
1222                 INIT_LIST_HEAD(&dummy_log->sb_list);
1223                 init_waitqueue_head(&dummy_log->syncwait);
1224                 dummy_log->no_integrity = 1;
1225                 /* Make up some stuff */
1226                 dummy_log->base = 0;
1227                 dummy_log->size = 1024;
1228                 rc = lmLogInit(dummy_log);
1229                 if (rc) {
1230                         kfree(dummy_log);
1231                         dummy_log = NULL;
1232                         mutex_unlock(&jfs_log_mutex);
1233                         return rc;
1234                 }
1235         }
1236
1237         LOG_LOCK(dummy_log);
1238         list_add(&JFS_SBI(sb)->log_list, &dummy_log->sb_list);
1239         JFS_SBI(sb)->log = dummy_log;
1240         LOG_UNLOCK(dummy_log);
1241         mutex_unlock(&jfs_log_mutex);
1242
1243         return 0;
1244 }
1245
1246 /*
1247  * NAME:        lmLogInit()
1248  *
1249  * FUNCTION:    log initialization at first log open.
1250  *
1251  *      logredo() (or logformat()) should have been run previously.
1252  *      initialize the log from log superblock.
1253  *      set the log state in the superblock to LOGMOUNT and
1254  *      write SYNCPT log record.
1255  *
1256  * PARAMETER:   log     - log structure
1257  *
1258  * RETURN:      0       - if ok
1259  *              -EINVAL - bad log magic number or superblock dirty
1260  *              error returned from logwait()
1261  *
1262  * serialization: single first open thread
1263  */
1264 int lmLogInit(struct jfs_log * log)
1265 {
1266         int rc = 0;
1267         struct lrd lrd;
1268         struct logsuper *logsuper;
1269         struct lbuf *bpsuper;
1270         struct lbuf *bp;
1271         struct logpage *lp;
1272         int lsn = 0;
1273
1274         jfs_info("lmLogInit: log:0x%p", log);
1275
1276         /* initialize the group commit serialization lock */
1277         LOGGC_LOCK_INIT(log);
1278
1279         /* allocate/initialize the log write serialization lock */
1280         LOG_LOCK_INIT(log);
1281
1282         LOGSYNC_LOCK_INIT(log);
1283
1284         INIT_LIST_HEAD(&log->synclist);
1285
1286         INIT_LIST_HEAD(&log->cqueue);
1287         log->flush_tblk = NULL;
1288
1289         log->count = 0;
1290
1291         /*
1292          * initialize log i/o
1293          */
1294         if ((rc = lbmLogInit(log)))
1295                 return rc;
1296
1297         if (!test_bit(log_INLINELOG, &log->flag))
1298                 log->l2bsize = L2LOGPSIZE;
1299
1300         /* check for disabled journaling to disk */
1301         if (log->no_integrity) {
1302                 /*
1303                  * Journal pages will still be filled.  When the time comes
1304                  * to actually do the I/O, the write is not done, and the
1305                  * endio routine is called directly.
1306                  */
1307                 bp = lbmAllocate(log , 0);
1308                 log->bp = bp;
1309                 bp->l_pn = bp->l_eor = 0;
1310         } else {
1311                 /*
1312                  * validate log superblock
1313                  */
1314                 if ((rc = lbmRead(log, 1, &bpsuper)))
1315                         goto errout10;
1316
1317                 logsuper = (struct logsuper *) bpsuper->l_ldata;
1318
1319                 if (logsuper->magic != cpu_to_le32(LOGMAGIC)) {
1320                         jfs_warn("*** Log Format Error ! ***");
1321                         rc = -EINVAL;
1322                         goto errout20;
1323                 }
1324
1325                 /* logredo() should have been run successfully. */
1326                 if (logsuper->state != cpu_to_le32(LOGREDONE)) {
1327                         jfs_warn("*** Log Is Dirty ! ***");
1328                         rc = -EINVAL;
1329                         goto errout20;
1330                 }
1331
1332                 /* initialize log from log superblock */
1333                 if (test_bit(log_INLINELOG,&log->flag)) {
1334                         if (log->size != le32_to_cpu(logsuper->size)) {
1335                                 rc = -EINVAL;
1336                                 goto errout20;
1337                         }
1338                         jfs_info("lmLogInit: inline log:0x%p base:0x%Lx "
1339                                  "size:0x%x", log,
1340                                  (unsigned long long) log->base, log->size);
1341                 } else {
1342                         if (memcmp(logsuper->uuid, log->uuid, 16)) {
1343                                 jfs_warn("wrong uuid on JFS log device");
1344                                 goto errout20;
1345                         }
1346                         log->size = le32_to_cpu(logsuper->size);
1347                         log->l2bsize = le32_to_cpu(logsuper->l2bsize);
1348                         jfs_info("lmLogInit: external log:0x%p base:0x%Lx "
1349                                  "size:0x%x", log,
1350                                  (unsigned long long) log->base, log->size);
1351                 }
1352
1353                 log->page = le32_to_cpu(logsuper->end) / LOGPSIZE;
1354                 log->eor = le32_to_cpu(logsuper->end) - (LOGPSIZE * log->page);
1355
1356                 /*
1357                  * initialize for log append write mode
1358                  */
1359                 /* establish current/end-of-log page/buffer */
1360                 if ((rc = lbmRead(log, log->page, &bp)))
1361                         goto errout20;
1362
1363                 lp = (struct logpage *) bp->l_ldata;
1364
1365                 jfs_info("lmLogInit: lsn:0x%x page:%d eor:%d:%d",
1366                          le32_to_cpu(logsuper->end), log->page, log->eor,
1367                          le16_to_cpu(lp->h.eor));
1368
1369                 log->bp = bp;
1370                 bp->l_pn = log->page;
1371                 bp->l_eor = log->eor;
1372
1373                 /* if current page is full, move on to next page */
1374                 if (log->eor >= LOGPSIZE - LOGPTLRSIZE)
1375                         lmNextPage(log);
1376
1377                 /*
1378                  * initialize log syncpoint
1379                  */
1380                 /*
1381                  * write the first SYNCPT record with syncpoint = 0
1382                  * (i.e., log redo up to HERE !);
1383                  * remove current page from lbm write queue at end of pageout
1384                  * (to write log superblock update), but do not release to
1385                  * freelist;
1386                  */
1387                 lrd.logtid = 0;
1388                 lrd.backchain = 0;
1389                 lrd.type = cpu_to_le16(LOG_SYNCPT);
1390                 lrd.length = 0;
1391                 lrd.log.syncpt.sync = 0;
1392                 lsn = lmWriteRecord(log, NULL, &lrd, NULL);
1393                 bp = log->bp;
1394                 bp->l_ceor = bp->l_eor;
1395                 lp = (struct logpage *) bp->l_ldata;
1396                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
1397                 lbmWrite(log, bp, lbmWRITE | lbmSYNC, 0);
1398                 if ((rc = lbmIOWait(bp, 0)))
1399                         goto errout30;
1400
1401                 /*
1402                  * update/write superblock
1403                  */
1404                 logsuper->state = cpu_to_le32(LOGMOUNT);
1405                 log->serial = le32_to_cpu(logsuper->serial) + 1;
1406                 logsuper->serial = cpu_to_le32(log->serial);
1407                 lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1408                 if ((rc = lbmIOWait(bpsuper, lbmFREE)))
1409                         goto errout30;
1410         }
1411
1412         /* initialize logsync parameters */
1413         log->logsize = (log->size - 2) << L2LOGPSIZE;
1414         log->lsn = lsn;
1415         log->syncpt = lsn;
1416         log->sync = log->syncpt;
1417         log->nextsync = LOGSYNC_DELTA(log->logsize);
1418
1419         jfs_info("lmLogInit: lsn:0x%x syncpt:0x%x sync:0x%x",
1420                  log->lsn, log->syncpt, log->sync);
1421
1422         /*
1423          * initialize for lazy/group commit
1424          */
1425         log->clsn = lsn;
1426
1427         return 0;
1428
1429         /*
1430          *      unwind on error
1431          */
1432       errout30:         /* release log page */
1433         log->wqueue = NULL;
1434         bp->l_wqnext = NULL;
1435         lbmFree(bp);
1436
1437       errout20:         /* release log superblock */
1438         lbmFree(bpsuper);
1439
1440       errout10:         /* unwind lbmLogInit() */
1441         lbmLogShutdown(log);
1442
1443         jfs_warn("lmLogInit: exit(%d)", rc);
1444         return rc;
1445 }
1446
1447
1448 /*
1449  * NAME:        lmLogClose()
1450  *
1451  * FUNCTION:    remove file system <ipmnt> from active list of log <iplog>
1452  *              and close it on last close.
1453  *
1454  * PARAMETER:   sb      - superblock
1455  *
1456  * RETURN:      errors from subroutines
1457  *
1458  * serialization:
1459  */
1460 int lmLogClose(struct super_block *sb)
1461 {
1462         struct jfs_sb_info *sbi = JFS_SBI(sb);
1463         struct jfs_log *log = sbi->log;
1464         struct block_device *bdev;
1465         int rc = 0;
1466
1467         jfs_info("lmLogClose: log:0x%p", log);
1468
1469         mutex_lock(&jfs_log_mutex);
1470         LOG_LOCK(log);
1471         list_del(&sbi->log_list);
1472         LOG_UNLOCK(log);
1473         sbi->log = NULL;
1474
1475         /*
1476          * We need to make sure all of the "written" metapages
1477          * actually make it to disk
1478          */
1479         sync_blockdev(sb->s_bdev);
1480
1481         if (test_bit(log_INLINELOG, &log->flag)) {
1482                 /*
1483                  *      in-line log in host file system
1484                  */
1485                 rc = lmLogShutdown(log);
1486                 kfree(log);
1487                 goto out;
1488         }
1489
1490         if (!log->no_integrity)
1491                 lmLogFileSystem(log, sbi, 0);
1492
1493         if (!list_empty(&log->sb_list))
1494                 goto out;
1495
1496         /*
1497          * TODO: ensure that the dummy_log is in a state to allow
1498          * lbmLogShutdown to deallocate all the buffers and call
1499          * kfree against dummy_log.  For now, leave dummy_log & its
1500          * buffers in memory, and resuse if another no-integrity mount
1501          * is requested.
1502          */
1503         if (log->no_integrity)
1504                 goto out;
1505
1506         /*
1507          *      external log as separate logical volume
1508          */
1509         list_del(&log->journal_list);
1510         bdev = log->bdev;
1511         rc = lmLogShutdown(log);
1512
1513         bd_release(bdev);
1514         blkdev_put(bdev);
1515
1516         kfree(log);
1517
1518       out:
1519         mutex_unlock(&jfs_log_mutex);
1520         jfs_info("lmLogClose: exit(%d)", rc);
1521         return rc;
1522 }
1523
1524
1525 /*
1526  * NAME:        jfs_flush_journal()
1527  *
1528  * FUNCTION:    initiate write of any outstanding transactions to the journal
1529  *              and optionally wait until they are all written to disk
1530  *
1531  *              wait == 0  flush until latest txn is committed, don't wait
1532  *              wait == 1  flush until latest txn is committed, wait
1533  *              wait > 1   flush until all txn's are complete, wait
1534  */
1535 void jfs_flush_journal(struct jfs_log *log, int wait)
1536 {
1537         int i;
1538         struct tblock *target = NULL;
1539         struct jfs_sb_info *sbi;
1540
1541         /* jfs_write_inode may call us during read-only mount */
1542         if (!log)
1543                 return;
1544
1545         jfs_info("jfs_flush_journal: log:0x%p wait=%d", log, wait);
1546
1547         LOGGC_LOCK(log);
1548
1549         if (!list_empty(&log->cqueue)) {
1550                 /*
1551                  * This ensures that we will keep writing to the journal as long
1552                  * as there are unwritten commit records
1553                  */
1554                 target = list_entry(log->cqueue.prev, struct tblock, cqueue);
1555
1556                 if (test_bit(log_FLUSH, &log->flag)) {
1557                         /*
1558                          * We're already flushing.
1559                          * if flush_tblk is NULL, we are flushing everything,
1560                          * so leave it that way.  Otherwise, update it to the
1561                          * latest transaction
1562                          */
1563                         if (log->flush_tblk)
1564                                 log->flush_tblk = target;
1565                 } else {
1566                         /* Only flush until latest transaction is committed */
1567                         log->flush_tblk = target;
1568                         set_bit(log_FLUSH, &log->flag);
1569
1570                         /*
1571                          * Initiate I/O on outstanding transactions
1572                          */
1573                         if (!(log->cflag & logGC_PAGEOUT)) {
1574                                 log->cflag |= logGC_PAGEOUT;
1575                                 lmGCwrite(log, 0);
1576                         }
1577                 }
1578         }
1579         if ((wait > 1) || test_bit(log_SYNCBARRIER, &log->flag)) {
1580                 /* Flush until all activity complete */
1581                 set_bit(log_FLUSH, &log->flag);
1582                 log->flush_tblk = NULL;
1583         }
1584
1585         if (wait && target && !(target->flag & tblkGC_COMMITTED)) {
1586                 DECLARE_WAITQUEUE(__wait, current);
1587
1588                 add_wait_queue(&target->gcwait, &__wait);
1589                 set_current_state(TASK_UNINTERRUPTIBLE);
1590                 LOGGC_UNLOCK(log);
1591                 schedule();
1592                 __set_current_state(TASK_RUNNING);
1593                 LOGGC_LOCK(log);
1594                 remove_wait_queue(&target->gcwait, &__wait);
1595         }
1596         LOGGC_UNLOCK(log);
1597
1598         if (wait < 2)
1599                 return;
1600
1601         list_for_each_entry(sbi, &log->sb_list, log_list) {
1602                 filemap_fdatawrite(sbi->ipbmap->i_mapping);
1603                 filemap_fdatawrite(sbi->ipimap->i_mapping);
1604                 filemap_fdatawrite(sbi->direct_inode->i_mapping);
1605         }
1606
1607         /*
1608          * If there was recent activity, we may need to wait
1609          * for the lazycommit thread to catch up
1610          */
1611         if ((!list_empty(&log->cqueue)) || !list_empty(&log->synclist)) {
1612                 for (i = 0; i < 200; i++) {     /* Too much? */
1613                         msleep(250);
1614                         if (list_empty(&log->cqueue) &&
1615                             list_empty(&log->synclist))
1616                                 break;
1617                 }
1618         }
1619         assert(list_empty(&log->cqueue));
1620
1621 #ifdef CONFIG_JFS_DEBUG
1622         if (!list_empty(&log->synclist)) {
1623                 struct logsyncblk *lp;
1624
1625                 list_for_each_entry(lp, &log->synclist, synclist) {
1626                         if (lp->xflag & COMMIT_PAGE) {
1627                                 struct metapage *mp = (struct metapage *)lp;
1628                                 dump_mem("orphan metapage", lp,
1629                                          sizeof(struct metapage));
1630                                 dump_mem("page", mp->page, sizeof(struct page));
1631                         }
1632                         else
1633                                 dump_mem("orphan tblock", lp,
1634                                          sizeof(struct tblock));
1635                 }
1636         }
1637 #endif
1638         //assert(list_empty(&log->synclist));
1639         clear_bit(log_FLUSH, &log->flag);
1640 }
1641
1642 /*
1643  * NAME:        lmLogShutdown()
1644  *
1645  * FUNCTION:    log shutdown at last LogClose().
1646  *
1647  *              write log syncpt record.
1648  *              update super block to set redone flag to 0.
1649  *
1650  * PARAMETER:   log     - log inode
1651  *
1652  * RETURN:      0       - success
1653  *
1654  * serialization: single last close thread
1655  */
1656 int lmLogShutdown(struct jfs_log * log)
1657 {
1658         int rc;
1659         struct lrd lrd;
1660         int lsn;
1661         struct logsuper *logsuper;
1662         struct lbuf *bpsuper;
1663         struct lbuf *bp;
1664         struct logpage *lp;
1665
1666         jfs_info("lmLogShutdown: log:0x%p", log);
1667
1668         jfs_flush_journal(log, 2);
1669
1670         /*
1671          * write the last SYNCPT record with syncpoint = 0
1672          * (i.e., log redo up to HERE !)
1673          */
1674         lrd.logtid = 0;
1675         lrd.backchain = 0;
1676         lrd.type = cpu_to_le16(LOG_SYNCPT);
1677         lrd.length = 0;
1678         lrd.log.syncpt.sync = 0;
1679
1680         lsn = lmWriteRecord(log, NULL, &lrd, NULL);
1681         bp = log->bp;
1682         lp = (struct logpage *) bp->l_ldata;
1683         lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
1684         lbmWrite(log, log->bp, lbmWRITE | lbmRELEASE | lbmSYNC, 0);
1685         lbmIOWait(log->bp, lbmFREE);
1686         log->bp = NULL;
1687
1688         /*
1689          * synchronous update log superblock
1690          * mark log state as shutdown cleanly
1691          * (i.e., Log does not need to be replayed).
1692          */
1693         if ((rc = lbmRead(log, 1, &bpsuper)))
1694                 goto out;
1695
1696         logsuper = (struct logsuper *) bpsuper->l_ldata;
1697         logsuper->state = cpu_to_le32(LOGREDONE);
1698         logsuper->end = cpu_to_le32(lsn);
1699         lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1700         rc = lbmIOWait(bpsuper, lbmFREE);
1701
1702         jfs_info("lmLogShutdown: lsn:0x%x page:%d eor:%d",
1703                  lsn, log->page, log->eor);
1704
1705       out:
1706         /*
1707          * shutdown per log i/o
1708          */
1709         lbmLogShutdown(log);
1710
1711         if (rc) {
1712                 jfs_warn("lmLogShutdown: exit(%d)", rc);
1713         }
1714         return rc;
1715 }
1716
1717
1718 /*
1719  * NAME:        lmLogFileSystem()
1720  *
1721  * FUNCTION:    insert (<activate> = true)/remove (<activate> = false)
1722  *      file system into/from log active file system list.
1723  *
1724  * PARAMETE:    log     - pointer to logs inode.
1725  *              fsdev   - kdev_t of filesystem.
1726  *              serial  - pointer to returned log serial number
1727  *              activate - insert/remove device from active list.
1728  *
1729  * RETURN:      0       - success
1730  *              errors returned by vms_iowait().
1731  */
1732 static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
1733                            int activate)
1734 {
1735         int rc = 0;
1736         int i;
1737         struct logsuper *logsuper;
1738         struct lbuf *bpsuper;
1739         char *uuid = sbi->uuid;
1740
1741         /*
1742          * insert/remove file system device to log active file system list.
1743          */
1744         if ((rc = lbmRead(log, 1, &bpsuper)))
1745                 return rc;
1746
1747         logsuper = (struct logsuper *) bpsuper->l_ldata;
1748         if (activate) {
1749                 for (i = 0; i < MAX_ACTIVE; i++)
1750                         if (!memcmp(logsuper->active[i].uuid, NULL_UUID, 16)) {
1751                                 memcpy(logsuper->active[i].uuid, uuid, 16);
1752                                 sbi->aggregate = i;
1753                                 break;
1754                         }
1755                 if (i == MAX_ACTIVE) {
1756                         jfs_warn("Too many file systems sharing journal!");
1757                         lbmFree(bpsuper);
1758                         return -EMFILE; /* Is there a better rc? */
1759                 }
1760         } else {
1761                 for (i = 0; i < MAX_ACTIVE; i++)
1762                         if (!memcmp(logsuper->active[i].uuid, uuid, 16)) {
1763                                 memcpy(logsuper->active[i].uuid, NULL_UUID, 16);
1764                                 break;
1765                         }
1766                 if (i == MAX_ACTIVE) {
1767                         jfs_warn("Somebody stomped on the journal!");
1768                         lbmFree(bpsuper);
1769                         return -EIO;
1770                 }
1771
1772         }
1773
1774         /*
1775          * synchronous write log superblock:
1776          *
1777          * write sidestream bypassing write queue:
1778          * at file system mount, log super block is updated for
1779          * activation of the file system before any log record
1780          * (MOUNT record) of the file system, and at file system
1781          * unmount, all meta data for the file system has been
1782          * flushed before log super block is updated for deactivation
1783          * of the file system.
1784          */
1785         lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1786         rc = lbmIOWait(bpsuper, lbmFREE);
1787
1788         return rc;
1789 }
1790
1791 /*
1792  *              log buffer manager (lbm)
1793  *              ------------------------
1794  *
1795  * special purpose buffer manager supporting log i/o requirements.
1796  *
1797  * per log write queue:
1798  * log pageout occurs in serial order by fifo write queue and
1799  * restricting to a single i/o in pregress at any one time.
1800  * a circular singly-linked list
1801  * (log->wrqueue points to the tail, and buffers are linked via
1802  * bp->wrqueue field), and
1803  * maintains log page in pageout ot waiting for pageout in serial pageout.
1804  */
1805
1806 /*
1807  *      lbmLogInit()
1808  *
1809  * initialize per log I/O setup at lmLogInit()
1810  */
1811 static int lbmLogInit(struct jfs_log * log)
1812 {                               /* log inode */
1813         int i;
1814         struct lbuf *lbuf;
1815
1816         jfs_info("lbmLogInit: log:0x%p", log);
1817
1818         /* initialize current buffer cursor */
1819         log->bp = NULL;
1820
1821         /* initialize log device write queue */
1822         log->wqueue = NULL;
1823
1824         /*
1825          * Each log has its own buffer pages allocated to it.  These are
1826          * not managed by the page cache.  This ensures that a transaction
1827          * writing to the log does not block trying to allocate a page from
1828          * the page cache (for the log).  This would be bad, since page
1829          * allocation waits on the kswapd thread that may be committing inodes
1830          * which would cause log activity.  Was that clear?  I'm trying to
1831          * avoid deadlock here.
1832          */
1833         init_waitqueue_head(&log->free_wait);
1834
1835         log->lbuf_free = NULL;
1836
1837         for (i = 0; i < LOGPAGES;) {
1838                 char *buffer;
1839                 uint offset;
1840                 struct page *page;
1841
1842                 buffer = (char *) get_zeroed_page(GFP_KERNEL);
1843                 if (buffer == NULL)
1844                         goto error;
1845                 page = virt_to_page(buffer);
1846                 for (offset = 0; offset < PAGE_SIZE; offset += LOGPSIZE) {
1847                         lbuf = kmalloc(sizeof(struct lbuf), GFP_KERNEL);
1848                         if (lbuf == NULL) {
1849                                 if (offset == 0)
1850                                         free_page((unsigned long) buffer);
1851                                 goto error;
1852                         }
1853                         if (offset) /* we already have one reference */
1854                                 get_page(page);
1855                         lbuf->l_offset = offset;
1856                         lbuf->l_ldata = buffer + offset;
1857                         lbuf->l_page = page;
1858                         lbuf->l_log = log;
1859                         init_waitqueue_head(&lbuf->l_ioevent);
1860
1861                         lbuf->l_freelist = log->lbuf_free;
1862                         log->lbuf_free = lbuf;
1863                         i++;
1864                 }
1865         }
1866
1867         return (0);
1868
1869       error:
1870         lbmLogShutdown(log);
1871         return -ENOMEM;
1872 }
1873
1874
1875 /*
1876  *      lbmLogShutdown()
1877  *
1878  * finalize per log I/O setup at lmLogShutdown()
1879  */
1880 static void lbmLogShutdown(struct jfs_log * log)
1881 {
1882         struct lbuf *lbuf;
1883
1884         jfs_info("lbmLogShutdown: log:0x%p", log);
1885
1886         lbuf = log->lbuf_free;
1887         while (lbuf) {
1888                 struct lbuf *next = lbuf->l_freelist;
1889                 __free_page(lbuf->l_page);
1890                 kfree(lbuf);
1891                 lbuf = next;
1892         }
1893 }
1894
1895
1896 /*
1897  *      lbmAllocate()
1898  *
1899  * allocate an empty log buffer
1900  */
1901 static struct lbuf *lbmAllocate(struct jfs_log * log, int pn)
1902 {
1903         struct lbuf *bp;
1904         unsigned long flags;
1905
1906         /*
1907          * recycle from log buffer freelist if any
1908          */
1909         LCACHE_LOCK(flags);
1910         LCACHE_SLEEP_COND(log->free_wait, (bp = log->lbuf_free), flags);
1911         log->lbuf_free = bp->l_freelist;
1912         LCACHE_UNLOCK(flags);
1913
1914         bp->l_flag = 0;
1915
1916         bp->l_wqnext = NULL;
1917         bp->l_freelist = NULL;
1918
1919         bp->l_pn = pn;
1920         bp->l_blkno = log->base + (pn << (L2LOGPSIZE - log->l2bsize));
1921         bp->l_ceor = 0;
1922
1923         return bp;
1924 }
1925
1926
1927 /*
1928  *      lbmFree()
1929  *
1930  * release a log buffer to freelist
1931  */
1932 static void lbmFree(struct lbuf * bp)
1933 {
1934         unsigned long flags;
1935
1936         LCACHE_LOCK(flags);
1937
1938         lbmfree(bp);
1939
1940         LCACHE_UNLOCK(flags);
1941 }
1942
1943 static void lbmfree(struct lbuf * bp)
1944 {
1945         struct jfs_log *log = bp->l_log;
1946
1947         assert(bp->l_wqnext == NULL);
1948
1949         /*
1950          * return the buffer to head of freelist
1951          */
1952         bp->l_freelist = log->lbuf_free;
1953         log->lbuf_free = bp;
1954
1955         wake_up(&log->free_wait);
1956         return;
1957 }
1958
1959
1960 /*
1961  * NAME:        lbmRedrive
1962  *
1963  * FUNCTION:    add a log buffer to the log redrive list
1964  *
1965  * PARAMETER:
1966  *      bp      - log buffer
1967  *
1968  * NOTES:
1969  *      Takes log_redrive_lock.
1970  */
1971 static inline void lbmRedrive(struct lbuf *bp)
1972 {
1973         unsigned long flags;
1974
1975         spin_lock_irqsave(&log_redrive_lock, flags);
1976         bp->l_redrive_next = log_redrive_list;
1977         log_redrive_list = bp;
1978         spin_unlock_irqrestore(&log_redrive_lock, flags);
1979
1980         wake_up_process(jfsIOthread);
1981 }
1982
1983
1984 /*
1985  *      lbmRead()
1986  */
1987 static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
1988 {
1989         struct bio *bio;
1990         struct lbuf *bp;
1991
1992         /*
1993          * allocate a log buffer
1994          */
1995         *bpp = bp = lbmAllocate(log, pn);
1996         jfs_info("lbmRead: bp:0x%p pn:0x%x", bp, pn);
1997
1998         bp->l_flag |= lbmREAD;
1999
2000         bio = bio_alloc(GFP_NOFS, 1);
2001
2002         bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
2003         bio->bi_bdev = log->bdev;
2004         bio->bi_io_vec[0].bv_page = bp->l_page;
2005         bio->bi_io_vec[0].bv_len = LOGPSIZE;
2006         bio->bi_io_vec[0].bv_offset = bp->l_offset;
2007
2008         bio->bi_vcnt = 1;
2009         bio->bi_idx = 0;
2010         bio->bi_size = LOGPSIZE;
2011
2012         bio->bi_end_io = lbmIODone;
2013         bio->bi_private = bp;
2014         submit_bio(READ_SYNC, bio);
2015
2016         wait_event(bp->l_ioevent, (bp->l_flag != lbmREAD));
2017
2018         return 0;
2019 }
2020
2021
2022 /*
2023  *      lbmWrite()
2024  *
2025  * buffer at head of pageout queue stays after completion of
2026  * partial-page pageout and redriven by explicit initiation of
2027  * pageout by caller until full-page pageout is completed and
2028  * released.
2029  *
2030  * device driver i/o done redrives pageout of new buffer at
2031  * head of pageout queue when current buffer at head of pageout
2032  * queue is released at the completion of its full-page pageout.
2033  *
2034  * LOGGC_LOCK() serializes lbmWrite() by lmNextPage() and lmGroupCommit().
2035  * LCACHE_LOCK() serializes xflag between lbmWrite() and lbmIODone()
2036  */
2037 static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag,
2038                      int cant_block)
2039 {
2040         struct lbuf *tail;
2041         unsigned long flags;
2042
2043         jfs_info("lbmWrite: bp:0x%p flag:0x%x pn:0x%x", bp, flag, bp->l_pn);
2044
2045         /* map the logical block address to physical block address */
2046         bp->l_blkno =
2047             log->base + (bp->l_pn << (L2LOGPSIZE - log->l2bsize));
2048
2049         LCACHE_LOCK(flags);             /* disable+lock */
2050
2051         /*
2052          * initialize buffer for device driver
2053          */
2054         bp->l_flag = flag;
2055
2056         /*
2057          *      insert bp at tail of write queue associated with log
2058          *
2059          * (request is either for bp already/currently at head of queue
2060          * or new bp to be inserted at tail)
2061          */
2062         tail = log->wqueue;
2063
2064         /* is buffer not already on write queue ? */
2065         if (bp->l_wqnext == NULL) {
2066                 /* insert at tail of wqueue */
2067                 if (tail == NULL) {
2068                         log->wqueue = bp;
2069                         bp->l_wqnext = bp;
2070                 } else {
2071                         log->wqueue = bp;
2072                         bp->l_wqnext = tail->l_wqnext;
2073                         tail->l_wqnext = bp;
2074                 }
2075
2076                 tail = bp;
2077         }
2078
2079         /* is buffer at head of wqueue and for write ? */
2080         if ((bp != tail->l_wqnext) || !(flag & lbmWRITE)) {
2081                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2082                 return;
2083         }
2084
2085         LCACHE_UNLOCK(flags);   /* unlock+enable */
2086
2087         if (cant_block)
2088                 lbmRedrive(bp);
2089         else if (flag & lbmSYNC)
2090                 lbmStartIO(bp);
2091         else {
2092                 LOGGC_UNLOCK(log);
2093                 lbmStartIO(bp);
2094                 LOGGC_LOCK(log);
2095         }
2096 }
2097
2098
2099 /*
2100  *      lbmDirectWrite()
2101  *
2102  * initiate pageout bypassing write queue for sidestream
2103  * (e.g., log superblock) write;
2104  */
2105 static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag)
2106 {
2107         jfs_info("lbmDirectWrite: bp:0x%p flag:0x%x pn:0x%x",
2108                  bp, flag, bp->l_pn);
2109
2110         /*
2111          * initialize buffer for device driver
2112          */
2113         bp->l_flag = flag | lbmDIRECT;
2114
2115         /* map the logical block address to physical block address */
2116         bp->l_blkno =
2117             log->base + (bp->l_pn << (L2LOGPSIZE - log->l2bsize));
2118
2119         /*
2120          *      initiate pageout of the page
2121          */
2122         lbmStartIO(bp);
2123 }
2124
2125
2126 /*
2127  * NAME:        lbmStartIO()
2128  *
2129  * FUNCTION:    Interface to DD strategy routine
2130  *
2131  * RETURN:      none
2132  *
2133  * serialization: LCACHE_LOCK() is NOT held during log i/o;
2134  */
2135 static void lbmStartIO(struct lbuf * bp)
2136 {
2137         struct bio *bio;
2138         struct jfs_log *log = bp->l_log;
2139
2140         jfs_info("lbmStartIO\n");
2141
2142         bio = bio_alloc(GFP_NOFS, 1);
2143         bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
2144         bio->bi_bdev = log->bdev;
2145         bio->bi_io_vec[0].bv_page = bp->l_page;
2146         bio->bi_io_vec[0].bv_len = LOGPSIZE;
2147         bio->bi_io_vec[0].bv_offset = bp->l_offset;
2148
2149         bio->bi_vcnt = 1;
2150         bio->bi_idx = 0;
2151         bio->bi_size = LOGPSIZE;
2152
2153         bio->bi_end_io = lbmIODone;
2154         bio->bi_private = bp;
2155
2156         /* check if journaling to disk has been disabled */
2157         if (log->no_integrity) {
2158                 bio->bi_size = 0;
2159                 lbmIODone(bio, 0, 0);
2160         } else {
2161                 submit_bio(WRITE_SYNC, bio);
2162                 INCREMENT(lmStat.submitted);
2163         }
2164 }
2165
2166
2167 /*
2168  *      lbmIOWait()
2169  */
2170 static int lbmIOWait(struct lbuf * bp, int flag)
2171 {
2172         unsigned long flags;
2173         int rc = 0;
2174
2175         jfs_info("lbmIOWait1: bp:0x%p flag:0x%x:0x%x", bp, bp->l_flag, flag);
2176
2177         LCACHE_LOCK(flags);             /* disable+lock */
2178
2179         LCACHE_SLEEP_COND(bp->l_ioevent, (bp->l_flag & lbmDONE), flags);
2180
2181         rc = (bp->l_flag & lbmERROR) ? -EIO : 0;
2182
2183         if (flag & lbmFREE)
2184                 lbmfree(bp);
2185
2186         LCACHE_UNLOCK(flags);   /* unlock+enable */
2187
2188         jfs_info("lbmIOWait2: bp:0x%p flag:0x%x:0x%x", bp, bp->l_flag, flag);
2189         return rc;
2190 }
2191
2192 /*
2193  *      lbmIODone()
2194  *
2195  * executed at INTIODONE level
2196  */
2197 static int lbmIODone(struct bio *bio, unsigned int bytes_done, int error)
2198 {
2199         struct lbuf *bp = bio->bi_private;
2200         struct lbuf *nextbp, *tail;
2201         struct jfs_log *log;
2202         unsigned long flags;
2203
2204         if (bio->bi_size)
2205                 return 1;
2206
2207         /*
2208          * get back jfs buffer bound to the i/o buffer
2209          */
2210         jfs_info("lbmIODone: bp:0x%p flag:0x%x", bp, bp->l_flag);
2211
2212         LCACHE_LOCK(flags);             /* disable+lock */
2213
2214         bp->l_flag |= lbmDONE;
2215
2216         if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
2217                 bp->l_flag |= lbmERROR;
2218
2219                 jfs_err("lbmIODone: I/O error in JFS log");
2220         }
2221
2222         bio_put(bio);
2223
2224         /*
2225          *      pagein completion
2226          */
2227         if (bp->l_flag & lbmREAD) {
2228                 bp->l_flag &= ~lbmREAD;
2229
2230                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2231
2232                 /* wakeup I/O initiator */
2233                 LCACHE_WAKEUP(&bp->l_ioevent);
2234
2235                 return 0;
2236         }
2237
2238         /*
2239          *      pageout completion
2240          *
2241          * the bp at the head of write queue has completed pageout.
2242          *
2243          * if single-commit/full-page pageout, remove the current buffer
2244          * from head of pageout queue, and redrive pageout with
2245          * the new buffer at head of pageout queue;
2246          * otherwise, the partial-page pageout buffer stays at
2247          * the head of pageout queue to be redriven for pageout
2248          * by lmGroupCommit() until full-page pageout is completed.
2249          */
2250         bp->l_flag &= ~lbmWRITE;
2251         INCREMENT(lmStat.pagedone);
2252
2253         /* update committed lsn */
2254         log = bp->l_log;
2255         log->clsn = (bp->l_pn << L2LOGPSIZE) + bp->l_ceor;
2256
2257         if (bp->l_flag & lbmDIRECT) {
2258                 LCACHE_WAKEUP(&bp->l_ioevent);
2259                 LCACHE_UNLOCK(flags);
2260                 return 0;
2261         }
2262
2263         tail = log->wqueue;
2264
2265         /* single element queue */
2266         if (bp == tail) {
2267                 /* remove head buffer of full-page pageout
2268                  * from log device write queue
2269                  */
2270                 if (bp->l_flag & lbmRELEASE) {
2271                         log->wqueue = NULL;
2272                         bp->l_wqnext = NULL;
2273                 }
2274         }
2275         /* multi element queue */
2276         else {
2277                 /* remove head buffer of full-page pageout
2278                  * from log device write queue
2279                  */
2280                 if (bp->l_flag & lbmRELEASE) {
2281                         nextbp = tail->l_wqnext = bp->l_wqnext;
2282                         bp->l_wqnext = NULL;
2283
2284                         /*
2285                          * redrive pageout of next page at head of write queue:
2286                          * redrive next page without any bound tblk
2287                          * (i.e., page w/o any COMMIT records), or
2288                          * first page of new group commit which has been
2289                          * queued after current page (subsequent pageout
2290                          * is performed synchronously, except page without
2291                          * any COMMITs) by lmGroupCommit() as indicated
2292                          * by lbmWRITE flag;
2293                          */
2294                         if (nextbp->l_flag & lbmWRITE) {
2295                                 /*
2296                                  * We can't do the I/O at interrupt time.
2297                                  * The jfsIO thread can do it
2298                                  */
2299                                 lbmRedrive(nextbp);
2300                         }
2301                 }
2302         }
2303
2304         /*
2305          *      synchronous pageout:
2306          *
2307          * buffer has not necessarily been removed from write queue
2308          * (e.g., synchronous write of partial-page with COMMIT):
2309          * leave buffer for i/o initiator to dispose
2310          */
2311         if (bp->l_flag & lbmSYNC) {
2312                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2313
2314                 /* wakeup I/O initiator */
2315                 LCACHE_WAKEUP(&bp->l_ioevent);
2316         }
2317
2318         /*
2319          *      Group Commit pageout:
2320          */
2321         else if (bp->l_flag & lbmGC) {
2322                 LCACHE_UNLOCK(flags);
2323                 lmPostGC(bp);
2324         }
2325
2326         /*
2327          *      asynchronous pageout:
2328          *
2329          * buffer must have been removed from write queue:
2330          * insert buffer at head of freelist where it can be recycled
2331          */
2332         else {
2333                 assert(bp->l_flag & lbmRELEASE);
2334                 assert(bp->l_flag & lbmFREE);
2335                 lbmfree(bp);
2336
2337                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2338         }
2339
2340         return 0;
2341 }
2342
2343 int jfsIOWait(void *arg)
2344 {
2345         struct lbuf *bp;
2346
2347         do {
2348                 spin_lock_irq(&log_redrive_lock);
2349                 while ((bp = log_redrive_list) != 0) {
2350                         log_redrive_list = bp->l_redrive_next;
2351                         bp->l_redrive_next = NULL;
2352                         spin_unlock_irq(&log_redrive_lock);
2353                         lbmStartIO(bp);
2354                         spin_lock_irq(&log_redrive_lock);
2355                 }
2356
2357                 if (freezing(current)) {
2358                         spin_unlock_irq(&log_redrive_lock);
2359                         refrigerator();
2360                 } else {
2361                         set_current_state(TASK_INTERRUPTIBLE);
2362                         spin_unlock_irq(&log_redrive_lock);
2363                         schedule();
2364                         __set_current_state(TASK_RUNNING);
2365                 }
2366         } while (!kthread_should_stop());
2367
2368         jfs_info("jfsIOWait being killed!");
2369         return 0;
2370 }
2371
2372 /*
2373  * NAME:        lmLogFormat()/jfs_logform()
2374  *
2375  * FUNCTION:    format file system log
2376  *
2377  * PARAMETERS:
2378  *      log     - volume log
2379  *      logAddress - start address of log space in FS block
2380  *      logSize - length of log space in FS block;
2381  *
2382  * RETURN:      0       - success
2383  *              -EIO    - i/o error
2384  *
2385  * XXX: We're synchronously writing one page at a time.  This needs to
2386  *      be improved by writing multiple pages at once.
2387  */
2388 int lmLogFormat(struct jfs_log *log, s64 logAddress, int logSize)
2389 {
2390         int rc = -EIO;
2391         struct jfs_sb_info *sbi;
2392         struct logsuper *logsuper;
2393         struct logpage *lp;
2394         int lspn;               /* log sequence page number */
2395         struct lrd *lrd_ptr;
2396         int npages = 0;
2397         struct lbuf *bp;
2398
2399         jfs_info("lmLogFormat: logAddress:%Ld logSize:%d",
2400                  (long long)logAddress, logSize);
2401
2402         sbi = list_entry(log->sb_list.next, struct jfs_sb_info, log_list);
2403
2404         /* allocate a log buffer */
2405         bp = lbmAllocate(log, 1);
2406
2407         npages = logSize >> sbi->l2nbperpage;
2408
2409         /*
2410          *      log space:
2411          *
2412          * page 0 - reserved;
2413          * page 1 - log superblock;
2414          * page 2 - log data page: A SYNC log record is written
2415          *          into this page at logform time;
2416          * pages 3-N - log data page: set to empty log data pages;
2417          */
2418         /*
2419          *      init log superblock: log page 1
2420          */
2421         logsuper = (struct logsuper *) bp->l_ldata;
2422
2423         logsuper->magic = cpu_to_le32(LOGMAGIC);
2424         logsuper->version = cpu_to_le32(LOGVERSION);
2425         logsuper->state = cpu_to_le32(LOGREDONE);
2426         logsuper->flag = cpu_to_le32(sbi->mntflag);     /* ? */
2427         logsuper->size = cpu_to_le32(npages);
2428         logsuper->bsize = cpu_to_le32(sbi->bsize);
2429         logsuper->l2bsize = cpu_to_le32(sbi->l2bsize);
2430         logsuper->end = cpu_to_le32(2 * LOGPSIZE + LOGPHDRSIZE + LOGRDSIZE);
2431
2432         bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2433         bp->l_blkno = logAddress + sbi->nbperpage;
2434         lbmStartIO(bp);
2435         if ((rc = lbmIOWait(bp, 0)))
2436                 goto exit;
2437
2438         /*
2439          *      init pages 2 to npages-1 as log data pages:
2440          *
2441          * log page sequence number (lpsn) initialization:
2442          *
2443          * pn:   0     1     2     3                 n-1
2444          *       +-----+-----+=====+=====+===.....===+=====+
2445          * lspn:             N-1   0     1           N-2
2446          *                   <--- N page circular file ---->
2447          *
2448          * the N (= npages-2) data pages of the log is maintained as
2449          * a circular file for the log records;
2450          * lpsn grows by 1 monotonically as each log page is written
2451          * to the circular file of the log;
2452          * and setLogpage() will not reset the page number even if
2453          * the eor is equal to LOGPHDRSIZE. In order for binary search
2454          * still work in find log end process, we have to simulate the
2455          * log wrap situation at the log format time.
2456          * The 1st log page written will have the highest lpsn. Then
2457          * the succeeding log pages will have ascending order of
2458          * the lspn starting from 0, ... (N-2)
2459          */
2460         lp = (struct logpage *) bp->l_ldata;
2461         /*
2462          * initialize 1st log page to be written: lpsn = N - 1,
2463          * write a SYNCPT log record is written to this page
2464          */
2465         lp->h.page = lp->t.page = cpu_to_le32(npages - 3);
2466         lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE + LOGRDSIZE);
2467
2468         lrd_ptr = (struct lrd *) &lp->data;
2469         lrd_ptr->logtid = 0;
2470         lrd_ptr->backchain = 0;
2471         lrd_ptr->type = cpu_to_le16(LOG_SYNCPT);
2472         lrd_ptr->length = 0;
2473         lrd_ptr->log.syncpt.sync = 0;
2474
2475         bp->l_blkno += sbi->nbperpage;
2476         bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2477         lbmStartIO(bp);
2478         if ((rc = lbmIOWait(bp, 0)))
2479                 goto exit;
2480
2481         /*
2482          *      initialize succeeding log pages: lpsn = 0, 1, ..., (N-2)
2483          */
2484         for (lspn = 0; lspn < npages - 3; lspn++) {
2485                 lp->h.page = lp->t.page = cpu_to_le32(lspn);
2486                 lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
2487
2488                 bp->l_blkno += sbi->nbperpage;
2489                 bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2490                 lbmStartIO(bp);
2491                 if ((rc = lbmIOWait(bp, 0)))
2492                         goto exit;
2493         }
2494
2495         rc = 0;
2496 exit:
2497         /*
2498          *      finalize log
2499          */
2500         /* release the buffer */
2501         lbmFree(bp);
2502
2503         return rc;
2504 }
2505
2506 #ifdef CONFIG_JFS_STATISTICS
2507 int jfs_lmstats_read(char *buffer, char **start, off_t offset, int length,
2508                       int *eof, void *data)
2509 {
2510         int len = 0;
2511         off_t begin;
2512
2513         len += sprintf(buffer,
2514                        "JFS Logmgr stats\n"
2515                        "================\n"
2516                        "commits = %d\n"
2517                        "writes submitted = %d\n"
2518                        "writes completed = %d\n"
2519                        "full pages submitted = %d\n"
2520                        "partial pages submitted = %d\n",
2521                        lmStat.commit,
2522                        lmStat.submitted,
2523                        lmStat.pagedone,
2524                        lmStat.full_page,
2525                        lmStat.partial_page);
2526
2527         begin = offset;
2528         *start = buffer + begin;
2529         len -= begin;
2530
2531         if (len > length)
2532                 len = length;
2533         else
2534                 *eof = 1;
2535
2536         if (len < 0)
2537                 len = 0;
2538
2539         return len;
2540 }
2541 #endif /* CONFIG_JFS_STATISTICS */