e1b8493b9aaaa10c8a80762efaf0316adfae869c
[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 <linux/seq_file.h>
73 #include <linux/slab.h>
74 #include "jfs_incore.h"
75 #include "jfs_filsys.h"
76 #include "jfs_metapage.h"
77 #include "jfs_superblock.h"
78 #include "jfs_txnmgr.h"
79 #include "jfs_debug.h"
80
81
82 /*
83  * lbuf's ready to be redriven.  Protected by log_redrive_lock (jfsIO thread)
84  */
85 static struct lbuf *log_redrive_list;
86 static DEFINE_SPINLOCK(log_redrive_lock);
87
88
89 /*
90  *      log read/write serialization (per log)
91  */
92 #define LOG_LOCK_INIT(log)      mutex_init(&(log)->loglock)
93 #define LOG_LOCK(log)           mutex_lock(&((log)->loglock))
94 #define LOG_UNLOCK(log)         mutex_unlock(&((log)->loglock))
95
96
97 /*
98  *      log group commit serialization (per log)
99  */
100
101 #define LOGGC_LOCK_INIT(log)    spin_lock_init(&(log)->gclock)
102 #define LOGGC_LOCK(log)         spin_lock_irq(&(log)->gclock)
103 #define LOGGC_UNLOCK(log)       spin_unlock_irq(&(log)->gclock)
104 #define LOGGC_WAKEUP(tblk)      wake_up_all(&(tblk)->gcwait)
105
106 /*
107  *      log sync serialization (per log)
108  */
109 #define LOGSYNC_DELTA(logsize)          min((logsize)/8, 128*LOGPSIZE)
110 #define LOGSYNC_BARRIER(logsize)        ((logsize)/4)
111 /*
112 #define LOGSYNC_DELTA(logsize)          min((logsize)/4, 256*LOGPSIZE)
113 #define LOGSYNC_BARRIER(logsize)        ((logsize)/2)
114 */
115
116
117 /*
118  *      log buffer cache synchronization
119  */
120 static DEFINE_SPINLOCK(jfsLCacheLock);
121
122 #define LCACHE_LOCK(flags)      spin_lock_irqsave(&jfsLCacheLock, flags)
123 #define LCACHE_UNLOCK(flags)    spin_unlock_irqrestore(&jfsLCacheLock, flags)
124
125 /*
126  * See __SLEEP_COND in jfs_locks.h
127  */
128 #define LCACHE_SLEEP_COND(wq, cond, flags)      \
129 do {                                            \
130         if (cond)                               \
131                 break;                          \
132         __SLEEP_COND(wq, cond, LCACHE_LOCK(flags), LCACHE_UNLOCK(flags)); \
133 } while (0)
134
135 #define LCACHE_WAKEUP(event)    wake_up(event)
136
137
138 /*
139  *      lbuf buffer cache (lCache) control
140  */
141 /* log buffer manager pageout control (cumulative, inclusive) */
142 #define lbmREAD         0x0001
143 #define lbmWRITE        0x0002  /* enqueue at tail of write queue;
144                                  * init pageout if at head of queue;
145                                  */
146 #define lbmRELEASE      0x0004  /* remove from write queue
147                                  * at completion of pageout;
148                                  * do not free/recycle it yet:
149                                  * caller will free it;
150                                  */
151 #define lbmSYNC         0x0008  /* do not return to freelist
152                                  * when removed from write queue;
153                                  */
154 #define lbmFREE         0x0010  /* return to freelist
155                                  * at completion of pageout;
156                                  * the buffer may be recycled;
157                                  */
158 #define lbmDONE         0x0020
159 #define lbmERROR        0x0040
160 #define lbmGC           0x0080  /* lbmIODone to perform post-GC processing
161                                  * of log page
162                                  */
163 #define lbmDIRECT       0x0100
164
165 /*
166  * Global list of active external journals
167  */
168 static LIST_HEAD(jfs_external_logs);
169 static struct jfs_log *dummy_log = NULL;
170 static DEFINE_MUTEX(jfs_log_mutex);
171
172 /*
173  * forward references
174  */
175 static int lmWriteRecord(struct jfs_log * log, struct tblock * tblk,
176                          struct lrd * lrd, struct tlock * tlck);
177
178 static int lmNextPage(struct jfs_log * log);
179 static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
180                            int activate);
181
182 static int open_inline_log(struct super_block *sb);
183 static int open_dummy_log(struct super_block *sb);
184 static int lbmLogInit(struct jfs_log * log);
185 static void lbmLogShutdown(struct jfs_log * log);
186 static struct lbuf *lbmAllocate(struct jfs_log * log, int);
187 static void lbmFree(struct lbuf * bp);
188 static void lbmfree(struct lbuf * bp);
189 static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp);
190 static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag, int cant_block);
191 static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag);
192 static int lbmIOWait(struct lbuf * bp, int flag);
193 static bio_end_io_t lbmIODone;
194 static void lbmStartIO(struct lbuf * bp);
195 static void lmGCwrite(struct jfs_log * log, int cant_block);
196 static int lmLogSync(struct jfs_log * log, int hard_sync);
197
198
199
200 /*
201  *      statistics
202  */
203 #ifdef CONFIG_JFS_STATISTICS
204 static struct lmStat {
205         uint commit;            /* # of commit */
206         uint pagedone;          /* # of page written */
207         uint submitted;         /* # of pages submitted */
208         uint full_page;         /* # of full pages submitted */
209         uint partial_page;      /* # of partial pages submitted */
210 } lmStat;
211 #endif
212
213 static void write_special_inodes(struct jfs_log *log,
214                                  int (*writer)(struct address_space *))
215 {
216         struct jfs_sb_info *sbi;
217
218         list_for_each_entry(sbi, &log->sb_list, log_list) {
219                 writer(sbi->ipbmap->i_mapping);
220                 writer(sbi->ipimap->i_mapping);
221                 writer(sbi->direct_inode->i_mapping);
222         }
223 }
224
225 /*
226  * NAME:        lmLog()
227  *
228  * FUNCTION:    write a log record;
229  *
230  * PARAMETER:
231  *
232  * RETURN:      lsn - offset to the next log record to write (end-of-log);
233  *              -1  - error;
234  *
235  * note: todo: log error handler
236  */
237 int lmLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
238           struct tlock * tlck)
239 {
240         int lsn;
241         int diffp, difft;
242         struct metapage *mp = NULL;
243         unsigned long flags;
244
245         jfs_info("lmLog: log:0x%p tblk:0x%p, lrd:0x%p tlck:0x%p",
246                  log, tblk, lrd, tlck);
247
248         LOG_LOCK(log);
249
250         /* log by (out-of-transaction) JFS ? */
251         if (tblk == NULL)
252                 goto writeRecord;
253
254         /* log from page ? */
255         if (tlck == NULL ||
256             tlck->type & tlckBTROOT || (mp = tlck->mp) == NULL)
257                 goto writeRecord;
258
259         /*
260          *      initialize/update page/transaction recovery lsn
261          */
262         lsn = log->lsn;
263
264         LOGSYNC_LOCK(log, flags);
265
266         /*
267          * initialize page lsn if first log write of the page
268          */
269         if (mp->lsn == 0) {
270                 mp->log = log;
271                 mp->lsn = lsn;
272                 log->count++;
273
274                 /* insert page at tail of logsynclist */
275                 list_add_tail(&mp->synclist, &log->synclist);
276         }
277
278         /*
279          *      initialize/update lsn of tblock of the page
280          *
281          * transaction inherits oldest lsn of pages associated
282          * with allocation/deallocation of resources (their
283          * log records are used to reconstruct allocation map
284          * at recovery time: inode for inode allocation map,
285          * B+-tree index of extent descriptors for block
286          * allocation map);
287          * allocation map pages inherit transaction lsn at
288          * commit time to allow forwarding log syncpt past log
289          * records associated with allocation/deallocation of
290          * resources only after persistent map of these map pages
291          * have been updated and propagated to home.
292          */
293         /*
294          * initialize transaction lsn:
295          */
296         if (tblk->lsn == 0) {
297                 /* inherit lsn of its first page logged */
298                 tblk->lsn = mp->lsn;
299                 log->count++;
300
301                 /* insert tblock after the page on logsynclist */
302                 list_add(&tblk->synclist, &mp->synclist);
303         }
304         /*
305          * update transaction lsn:
306          */
307         else {
308                 /* inherit oldest/smallest lsn of page */
309                 logdiff(diffp, mp->lsn, log);
310                 logdiff(difft, tblk->lsn, log);
311                 if (diffp < difft) {
312                         /* update tblock lsn with page lsn */
313                         tblk->lsn = mp->lsn;
314
315                         /* move tblock after page on logsynclist */
316                         list_move(&tblk->synclist, &mp->synclist);
317                 }
318         }
319
320         LOGSYNC_UNLOCK(log, flags);
321
322         /*
323          *      write the log record
324          */
325       writeRecord:
326         lsn = lmWriteRecord(log, tblk, lrd, tlck);
327
328         /*
329          * forward log syncpt if log reached next syncpt trigger
330          */
331         logdiff(diffp, lsn, log);
332         if (diffp >= log->nextsync)
333                 lsn = lmLogSync(log, 0);
334
335         /* update end-of-log lsn */
336         log->lsn = lsn;
337
338         LOG_UNLOCK(log);
339
340         /* return end-of-log address */
341         return lsn;
342 }
343
344 /*
345  * NAME:        lmWriteRecord()
346  *
347  * FUNCTION:    move the log record to current log page
348  *
349  * PARAMETER:   cd      - commit descriptor
350  *
351  * RETURN:      end-of-log address
352  *
353  * serialization: LOG_LOCK() held on entry/exit
354  */
355 static int
356 lmWriteRecord(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
357               struct tlock * tlck)
358 {
359         int lsn = 0;            /* end-of-log address */
360         struct lbuf *bp;        /* dst log page buffer */
361         struct logpage *lp;     /* dst log page */
362         caddr_t dst;            /* destination address in log page */
363         int dstoffset;          /* end-of-log offset in log page */
364         int freespace;          /* free space in log page */
365         caddr_t p;              /* src meta-data page */
366         caddr_t src;
367         int srclen;
368         int nbytes;             /* number of bytes to move */
369         int i;
370         int len;
371         struct linelock *linelock;
372         struct lv *lv;
373         struct lvd *lvd;
374         int l2linesize;
375
376         len = 0;
377
378         /* retrieve destination log page to write */
379         bp = (struct lbuf *) log->bp;
380         lp = (struct logpage *) bp->l_ldata;
381         dstoffset = log->eor;
382
383         /* any log data to write ? */
384         if (tlck == NULL)
385                 goto moveLrd;
386
387         /*
388          *      move log record data
389          */
390         /* retrieve source meta-data page to log */
391         if (tlck->flag & tlckPAGELOCK) {
392                 p = (caddr_t) (tlck->mp->data);
393                 linelock = (struct linelock *) & tlck->lock;
394         }
395         /* retrieve source in-memory inode to log */
396         else if (tlck->flag & tlckINODELOCK) {
397                 if (tlck->type & tlckDTREE)
398                         p = (caddr_t) &JFS_IP(tlck->ip)->i_dtroot;
399                 else
400                         p = (caddr_t) &JFS_IP(tlck->ip)->i_xtroot;
401                 linelock = (struct linelock *) & tlck->lock;
402         }
403 #ifdef  _JFS_WIP
404         else if (tlck->flag & tlckINLINELOCK) {
405
406                 inlinelock = (struct inlinelock *) & tlck;
407                 p = (caddr_t) & inlinelock->pxd;
408                 linelock = (struct linelock *) & tlck;
409         }
410 #endif                          /* _JFS_WIP */
411         else {
412                 jfs_err("lmWriteRecord: UFO tlck:0x%p", tlck);
413                 return 0;       /* Probably should trap */
414         }
415         l2linesize = linelock->l2linesize;
416
417       moveData:
418         ASSERT(linelock->index <= linelock->maxcnt);
419
420         lv = linelock->lv;
421         for (i = 0; i < linelock->index; i++, lv++) {
422                 if (lv->length == 0)
423                         continue;
424
425                 /* is page full ? */
426                 if (dstoffset >= LOGPSIZE - LOGPTLRSIZE) {
427                         /* page become full: move on to next page */
428                         lmNextPage(log);
429
430                         bp = log->bp;
431                         lp = (struct logpage *) bp->l_ldata;
432                         dstoffset = LOGPHDRSIZE;
433                 }
434
435                 /*
436                  * move log vector data
437                  */
438                 src = (u8 *) p + (lv->offset << l2linesize);
439                 srclen = lv->length << l2linesize;
440                 len += srclen;
441                 while (srclen > 0) {
442                         freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
443                         nbytes = min(freespace, srclen);
444                         dst = (caddr_t) lp + dstoffset;
445                         memcpy(dst, src, nbytes);
446                         dstoffset += nbytes;
447
448                         /* is page not full ? */
449                         if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
450                                 break;
451
452                         /* page become full: move on to next page */
453                         lmNextPage(log);
454
455                         bp = (struct lbuf *) log->bp;
456                         lp = (struct logpage *) bp->l_ldata;
457                         dstoffset = LOGPHDRSIZE;
458
459                         srclen -= nbytes;
460                         src += nbytes;
461                 }
462
463                 /*
464                  * move log vector descriptor
465                  */
466                 len += 4;
467                 lvd = (struct lvd *) ((caddr_t) lp + dstoffset);
468                 lvd->offset = cpu_to_le16(lv->offset);
469                 lvd->length = cpu_to_le16(lv->length);
470                 dstoffset += 4;
471                 jfs_info("lmWriteRecord: lv offset:%d length:%d",
472                          lv->offset, lv->length);
473         }
474
475         if ((i = linelock->next)) {
476                 linelock = (struct linelock *) lid_to_tlock(i);
477                 goto moveData;
478         }
479
480         /*
481          *      move log record descriptor
482          */
483       moveLrd:
484         lrd->length = cpu_to_le16(len);
485
486         src = (caddr_t) lrd;
487         srclen = LOGRDSIZE;
488
489         while (srclen > 0) {
490                 freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
491                 nbytes = min(freespace, srclen);
492                 dst = (caddr_t) lp + dstoffset;
493                 memcpy(dst, src, nbytes);
494
495                 dstoffset += nbytes;
496                 srclen -= nbytes;
497
498                 /* are there more to move than freespace of page ? */
499                 if (srclen)
500                         goto pageFull;
501
502                 /*
503                  * end of log record descriptor
504                  */
505
506                 /* update last log record eor */
507                 log->eor = dstoffset;
508                 bp->l_eor = dstoffset;
509                 lsn = (log->page << L2LOGPSIZE) + dstoffset;
510
511                 if (lrd->type & cpu_to_le16(LOG_COMMIT)) {
512                         tblk->clsn = lsn;
513                         jfs_info("wr: tclsn:0x%x, beor:0x%x", tblk->clsn,
514                                  bp->l_eor);
515
516                         INCREMENT(lmStat.commit);       /* # of commit */
517
518                         /*
519                          * enqueue tblock for group commit:
520                          *
521                          * enqueue tblock of non-trivial/synchronous COMMIT
522                          * at tail of group commit queue
523                          * (trivial/asynchronous COMMITs are ignored by
524                          * group commit.)
525                          */
526                         LOGGC_LOCK(log);
527
528                         /* init tblock gc state */
529                         tblk->flag = tblkGC_QUEUE;
530                         tblk->bp = log->bp;
531                         tblk->pn = log->page;
532                         tblk->eor = log->eor;
533
534                         /* enqueue transaction to commit queue */
535                         list_add_tail(&tblk->cqueue, &log->cqueue);
536
537                         LOGGC_UNLOCK(log);
538                 }
539
540                 jfs_info("lmWriteRecord: lrd:0x%04x bp:0x%p pn:%d eor:0x%x",
541                         le16_to_cpu(lrd->type), log->bp, log->page, dstoffset);
542
543                 /* page not full ? */
544                 if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
545                         return lsn;
546
547               pageFull:
548                 /* page become full: move on to next page */
549                 lmNextPage(log);
550
551                 bp = (struct lbuf *) log->bp;
552                 lp = (struct logpage *) bp->l_ldata;
553                 dstoffset = LOGPHDRSIZE;
554                 src += nbytes;
555         }
556
557         return lsn;
558 }
559
560
561 /*
562  * NAME:        lmNextPage()
563  *
564  * FUNCTION:    write current page and allocate next page.
565  *
566  * PARAMETER:   log
567  *
568  * RETURN:      0
569  *
570  * serialization: LOG_LOCK() held on entry/exit
571  */
572 static int lmNextPage(struct jfs_log * log)
573 {
574         struct logpage *lp;
575         int lspn;               /* log sequence page number */
576         int pn;                 /* current page number */
577         struct lbuf *bp;
578         struct lbuf *nextbp;
579         struct tblock *tblk;
580
581         /* get current log page number and log sequence page number */
582         pn = log->page;
583         bp = log->bp;
584         lp = (struct logpage *) bp->l_ldata;
585         lspn = le32_to_cpu(lp->h.page);
586
587         LOGGC_LOCK(log);
588
589         /*
590          *      write or queue the full page at the tail of write queue
591          */
592         /* get the tail tblk on commit queue */
593         if (list_empty(&log->cqueue))
594                 tblk = NULL;
595         else
596                 tblk = list_entry(log->cqueue.prev, struct tblock, cqueue);
597
598         /* every tblk who has COMMIT record on the current page,
599          * and has not been committed, must be on commit queue
600          * since tblk is queued at commit queueu at the time
601          * of writing its COMMIT record on the page before
602          * page becomes full (even though the tblk thread
603          * who wrote COMMIT record may have been suspended
604          * currently);
605          */
606
607         /* is page bound with outstanding tail tblk ? */
608         if (tblk && tblk->pn == pn) {
609                 /* mark tblk for end-of-page */
610                 tblk->flag |= tblkGC_EOP;
611
612                 if (log->cflag & logGC_PAGEOUT) {
613                         /* if page is not already on write queue,
614                          * just enqueue (no lbmWRITE to prevent redrive)
615                          * buffer to wqueue to ensure correct serial order
616                          * of the pages since log pages will be added
617                          * continuously
618                          */
619                         if (bp->l_wqnext == NULL)
620                                 lbmWrite(log, bp, 0, 0);
621                 } else {
622                         /*
623                          * No current GC leader, initiate group commit
624                          */
625                         log->cflag |= logGC_PAGEOUT;
626                         lmGCwrite(log, 0);
627                 }
628         }
629         /* page is not bound with outstanding tblk:
630          * init write or mark it to be redriven (lbmWRITE)
631          */
632         else {
633                 /* finalize the page */
634                 bp->l_ceor = bp->l_eor;
635                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
636                 lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE, 0);
637         }
638         LOGGC_UNLOCK(log);
639
640         /*
641          *      allocate/initialize next page
642          */
643         /* if log wraps, the first data page of log is 2
644          * (0 never used, 1 is superblock).
645          */
646         log->page = (pn == log->size - 1) ? 2 : pn + 1;
647         log->eor = LOGPHDRSIZE; /* ? valid page empty/full at logRedo() */
648
649         /* allocate/initialize next log page buffer */
650         nextbp = lbmAllocate(log, log->page);
651         nextbp->l_eor = log->eor;
652         log->bp = nextbp;
653
654         /* initialize next log page */
655         lp = (struct logpage *) nextbp->l_ldata;
656         lp->h.page = lp->t.page = cpu_to_le32(lspn + 1);
657         lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
658
659         return 0;
660 }
661
662
663 /*
664  * NAME:        lmGroupCommit()
665  *
666  * FUNCTION:    group commit
667  *      initiate pageout of the pages with COMMIT in the order of
668  *      page number - redrive pageout of the page at the head of
669  *      pageout queue until full page has been written.
670  *
671  * RETURN:
672  *
673  * NOTE:
674  *      LOGGC_LOCK serializes log group commit queue, and
675  *      transaction blocks on the commit queue.
676  *      N.B. LOG_LOCK is NOT held during lmGroupCommit().
677  */
678 int lmGroupCommit(struct jfs_log * log, struct tblock * tblk)
679 {
680         int rc = 0;
681
682         LOGGC_LOCK(log);
683
684         /* group committed already ? */
685         if (tblk->flag & tblkGC_COMMITTED) {
686                 if (tblk->flag & tblkGC_ERROR)
687                         rc = -EIO;
688
689                 LOGGC_UNLOCK(log);
690                 return rc;
691         }
692         jfs_info("lmGroup Commit: tblk = 0x%p, gcrtc = %d", tblk, log->gcrtc);
693
694         if (tblk->xflag & COMMIT_LAZY)
695                 tblk->flag |= tblkGC_LAZY;
696
697         if ((!(log->cflag & logGC_PAGEOUT)) && (!list_empty(&log->cqueue)) &&
698             (!(tblk->xflag & COMMIT_LAZY) || test_bit(log_FLUSH, &log->flag)
699              || jfs_tlocks_low)) {
700                 /*
701                  * No pageout in progress
702                  *
703                  * start group commit as its group leader.
704                  */
705                 log->cflag |= logGC_PAGEOUT;
706
707                 lmGCwrite(log, 0);
708         }
709
710         if (tblk->xflag & COMMIT_LAZY) {
711                 /*
712                  * Lazy transactions can leave now
713                  */
714                 LOGGC_UNLOCK(log);
715                 return 0;
716         }
717
718         /* lmGCwrite gives up LOGGC_LOCK, check again */
719
720         if (tblk->flag & tblkGC_COMMITTED) {
721                 if (tblk->flag & tblkGC_ERROR)
722                         rc = -EIO;
723
724                 LOGGC_UNLOCK(log);
725                 return rc;
726         }
727
728         /* upcount transaction waiting for completion
729          */
730         log->gcrtc++;
731         tblk->flag |= tblkGC_READY;
732
733         __SLEEP_COND(tblk->gcwait, (tblk->flag & tblkGC_COMMITTED),
734                      LOGGC_LOCK(log), LOGGC_UNLOCK(log));
735
736         /* removed from commit queue */
737         if (tblk->flag & tblkGC_ERROR)
738                 rc = -EIO;
739
740         LOGGC_UNLOCK(log);
741         return rc;
742 }
743
744 /*
745  * NAME:        lmGCwrite()
746  *
747  * FUNCTION:    group commit write
748  *      initiate write of log page, building a group of all transactions
749  *      with commit records on that page.
750  *
751  * RETURN:      None
752  *
753  * NOTE:
754  *      LOGGC_LOCK must be held by caller.
755  *      N.B. LOG_LOCK is NOT held during lmGroupCommit().
756  */
757 static void lmGCwrite(struct jfs_log * log, int cant_write)
758 {
759         struct lbuf *bp;
760         struct logpage *lp;
761         int gcpn;               /* group commit page number */
762         struct tblock *tblk;
763         struct tblock *xtblk = NULL;
764
765         /*
766          * build the commit group of a log page
767          *
768          * scan commit queue and make a commit group of all
769          * transactions with COMMIT records on the same log page.
770          */
771         /* get the head tblk on the commit queue */
772         gcpn = list_entry(log->cqueue.next, struct tblock, cqueue)->pn;
773
774         list_for_each_entry(tblk, &log->cqueue, cqueue) {
775                 if (tblk->pn != gcpn)
776                         break;
777
778                 xtblk = tblk;
779
780                 /* state transition: (QUEUE, READY) -> COMMIT */
781                 tblk->flag |= tblkGC_COMMIT;
782         }
783         tblk = xtblk;           /* last tblk of the page */
784
785         /*
786          * pageout to commit transactions on the log page.
787          */
788         bp = (struct lbuf *) tblk->bp;
789         lp = (struct logpage *) bp->l_ldata;
790         /* is page already full ? */
791         if (tblk->flag & tblkGC_EOP) {
792                 /* mark page to free at end of group commit of the page */
793                 tblk->flag &= ~tblkGC_EOP;
794                 tblk->flag |= tblkGC_FREE;
795                 bp->l_ceor = bp->l_eor;
796                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
797                 lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmGC,
798                          cant_write);
799                 INCREMENT(lmStat.full_page);
800         }
801         /* page is not yet full */
802         else {
803                 bp->l_ceor = tblk->eor; /* ? bp->l_ceor = bp->l_eor; */
804                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
805                 lbmWrite(log, bp, lbmWRITE | lbmGC, cant_write);
806                 INCREMENT(lmStat.partial_page);
807         }
808 }
809
810 /*
811  * NAME:        lmPostGC()
812  *
813  * FUNCTION:    group commit post-processing
814  *      Processes transactions after their commit records have been written
815  *      to disk, redriving log I/O if necessary.
816  *
817  * RETURN:      None
818  *
819  * NOTE:
820  *      This routine is called a interrupt time by lbmIODone
821  */
822 static void lmPostGC(struct lbuf * bp)
823 {
824         unsigned long flags;
825         struct jfs_log *log = bp->l_log;
826         struct logpage *lp;
827         struct tblock *tblk, *temp;
828
829         //LOGGC_LOCK(log);
830         spin_lock_irqsave(&log->gclock, flags);
831         /*
832          * current pageout of group commit completed.
833          *
834          * remove/wakeup transactions from commit queue who were
835          * group committed with the current log page
836          */
837         list_for_each_entry_safe(tblk, temp, &log->cqueue, cqueue) {
838                 if (!(tblk->flag & tblkGC_COMMIT))
839                         break;
840                 /* if transaction was marked GC_COMMIT then
841                  * it has been shipped in the current pageout
842                  * and made it to disk - it is committed.
843                  */
844
845                 if (bp->l_flag & lbmERROR)
846                         tblk->flag |= tblkGC_ERROR;
847
848                 /* remove it from the commit queue */
849                 list_del(&tblk->cqueue);
850                 tblk->flag &= ~tblkGC_QUEUE;
851
852                 if (tblk == log->flush_tblk) {
853                         /* we can stop flushing the log now */
854                         clear_bit(log_FLUSH, &log->flag);
855                         log->flush_tblk = NULL;
856                 }
857
858                 jfs_info("lmPostGC: tblk = 0x%p, flag = 0x%x", tblk,
859                          tblk->flag);
860
861                 if (!(tblk->xflag & COMMIT_FORCE))
862                         /*
863                          * Hand tblk over to lazy commit thread
864                          */
865                         txLazyUnlock(tblk);
866                 else {
867                         /* state transition: COMMIT -> COMMITTED */
868                         tblk->flag |= tblkGC_COMMITTED;
869
870                         if (tblk->flag & tblkGC_READY)
871                                 log->gcrtc--;
872
873                         LOGGC_WAKEUP(tblk);
874                 }
875
876                 /* was page full before pageout ?
877                  * (and this is the last tblk bound with the page)
878                  */
879                 if (tblk->flag & tblkGC_FREE)
880                         lbmFree(bp);
881                 /* did page become full after pageout ?
882                  * (and this is the last tblk bound with the page)
883                  */
884                 else if (tblk->flag & tblkGC_EOP) {
885                         /* finalize the page */
886                         lp = (struct logpage *) bp->l_ldata;
887                         bp->l_ceor = bp->l_eor;
888                         lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
889                         jfs_info("lmPostGC: calling lbmWrite");
890                         lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE,
891                                  1);
892                 }
893
894         }
895
896         /* are there any transactions who have entered lnGroupCommit()
897          * (whose COMMITs are after that of the last log page written.
898          * They are waiting for new group commit (above at (SLEEP 1))
899          * or lazy transactions are on a full (queued) log page,
900          * select the latest ready transaction as new group leader and
901          * wake her up to lead her group.
902          */
903         if ((!list_empty(&log->cqueue)) &&
904             ((log->gcrtc > 0) || (tblk->bp->l_wqnext != NULL) ||
905              test_bit(log_FLUSH, &log->flag) || jfs_tlocks_low))
906                 /*
907                  * Call lmGCwrite with new group leader
908                  */
909                 lmGCwrite(log, 1);
910
911         /* no transaction are ready yet (transactions are only just
912          * queued (GC_QUEUE) and not entered for group commit yet).
913          * the first transaction entering group commit
914          * will elect herself as new group leader.
915          */
916         else
917                 log->cflag &= ~logGC_PAGEOUT;
918
919         //LOGGC_UNLOCK(log);
920         spin_unlock_irqrestore(&log->gclock, flags);
921         return;
922 }
923
924 /*
925  * NAME:        lmLogSync()
926  *
927  * FUNCTION:    write log SYNCPT record for specified log
928  *      if new sync address is available
929  *      (normally the case if sync() is executed by back-ground
930  *      process).
931  *      calculate new value of i_nextsync which determines when
932  *      this code is called again.
933  *
934  * PARAMETERS:  log     - log structure
935  *              hard_sync - 1 to force all metadata to be written
936  *
937  * RETURN:      0
938  *
939  * serialization: LOG_LOCK() held on entry/exit
940  */
941 static int lmLogSync(struct jfs_log * log, int hard_sync)
942 {
943         int logsize;
944         int written;            /* written since last syncpt */
945         int free;               /* free space left available */
946         int delta;              /* additional delta to write normally */
947         int more;               /* additional write granted */
948         struct lrd lrd;
949         int lsn;
950         struct logsyncblk *lp;
951         unsigned long flags;
952
953         /* push dirty metapages out to disk */
954         if (hard_sync)
955                 write_special_inodes(log, filemap_fdatawrite);
956         else
957                 write_special_inodes(log, filemap_flush);
958
959         /*
960          *      forward syncpt
961          */
962         /* if last sync is same as last syncpt,
963          * invoke sync point forward processing to update sync.
964          */
965
966         if (log->sync == log->syncpt) {
967                 LOGSYNC_LOCK(log, flags);
968                 if (list_empty(&log->synclist))
969                         log->sync = log->lsn;
970                 else {
971                         lp = list_entry(log->synclist.next,
972                                         struct logsyncblk, synclist);
973                         log->sync = lp->lsn;
974                 }
975                 LOGSYNC_UNLOCK(log, flags);
976
977         }
978
979         /* if sync is different from last syncpt,
980          * write a SYNCPT record with syncpt = sync.
981          * reset syncpt = sync
982          */
983         if (log->sync != log->syncpt) {
984                 lrd.logtid = 0;
985                 lrd.backchain = 0;
986                 lrd.type = cpu_to_le16(LOG_SYNCPT);
987                 lrd.length = 0;
988                 lrd.log.syncpt.sync = cpu_to_le32(log->sync);
989                 lsn = lmWriteRecord(log, NULL, &lrd, NULL);
990
991                 log->syncpt = log->sync;
992         } else
993                 lsn = log->lsn;
994
995         /*
996          *      setup next syncpt trigger (SWAG)
997          */
998         logsize = log->logsize;
999
1000         logdiff(written, lsn, log);
1001         free = logsize - written;
1002         delta = LOGSYNC_DELTA(logsize);
1003         more = min(free / 2, delta);
1004         if (more < 2 * LOGPSIZE) {
1005                 jfs_warn("\n ... Log Wrap ... Log Wrap ... Log Wrap ...\n");
1006                 /*
1007                  *      log wrapping
1008                  *
1009                  * option 1 - panic ? No.!
1010                  * option 2 - shutdown file systems
1011                  *            associated with log ?
1012                  * option 3 - extend log ?
1013                  * option 4 - second chance
1014                  *
1015                  * mark log wrapped, and continue.
1016                  * when all active transactions are completed,
1017                  * mark log valid for recovery.
1018                  * if crashed during invalid state, log state
1019                  * implies invalid log, forcing fsck().
1020                  */
1021                 /* mark log state log wrap in log superblock */
1022                 /* log->state = LOGWRAP; */
1023
1024                 /* reset sync point computation */
1025                 log->syncpt = log->sync = lsn;
1026                 log->nextsync = delta;
1027         } else
1028                 /* next syncpt trigger = written + more */
1029                 log->nextsync = written + more;
1030
1031         /* if number of bytes written from last sync point is more
1032          * than 1/4 of the log size, stop new transactions from
1033          * starting until all current transactions are completed
1034          * by setting syncbarrier flag.
1035          */
1036         if (!test_bit(log_SYNCBARRIER, &log->flag) &&
1037             (written > LOGSYNC_BARRIER(logsize)) && log->active) {
1038                 set_bit(log_SYNCBARRIER, &log->flag);
1039                 jfs_info("log barrier on: lsn=0x%x syncpt=0x%x", lsn,
1040                          log->syncpt);
1041                 /*
1042                  * We may have to initiate group commit
1043                  */
1044                 jfs_flush_journal(log, 0);
1045         }
1046
1047         return lsn;
1048 }
1049
1050 /*
1051  * NAME:        jfs_syncpt
1052  *
1053  * FUNCTION:    write log SYNCPT record for specified log
1054  *
1055  * PARAMETERS:  log       - log structure
1056  *              hard_sync - set to 1 to force metadata to be written
1057  */
1058 void jfs_syncpt(struct jfs_log *log, int hard_sync)
1059 {       LOG_LOCK(log);
1060         lmLogSync(log, hard_sync);
1061         LOG_UNLOCK(log);
1062 }
1063
1064 /*
1065  * NAME:        lmLogOpen()
1066  *
1067  * FUNCTION:    open the log on first open;
1068  *      insert filesystem in the active list of the log.
1069  *
1070  * PARAMETER:   ipmnt   - file system mount inode
1071  *              iplog   - log inode (out)
1072  *
1073  * RETURN:
1074  *
1075  * serialization:
1076  */
1077 int lmLogOpen(struct super_block *sb)
1078 {
1079         int rc;
1080         struct block_device *bdev;
1081         struct jfs_log *log;
1082         struct jfs_sb_info *sbi = JFS_SBI(sb);
1083
1084         if (sbi->flag & JFS_NOINTEGRITY)
1085                 return open_dummy_log(sb);
1086
1087         if (sbi->mntflag & JFS_INLINELOG)
1088                 return open_inline_log(sb);
1089
1090         mutex_lock(&jfs_log_mutex);
1091         list_for_each_entry(log, &jfs_external_logs, journal_list) {
1092                 if (log->bdev->bd_dev == sbi->logdev) {
1093                         if (memcmp(log->uuid, sbi->loguuid,
1094                                    sizeof(log->uuid))) {
1095                                 jfs_warn("wrong uuid on JFS journal\n");
1096                                 mutex_unlock(&jfs_log_mutex);
1097                                 return -EINVAL;
1098                         }
1099                         /*
1100                          * add file system to log active file system list
1101                          */
1102                         if ((rc = lmLogFileSystem(log, sbi, 1))) {
1103                                 mutex_unlock(&jfs_log_mutex);
1104                                 return rc;
1105                         }
1106                         goto journal_found;
1107                 }
1108         }
1109
1110         if (!(log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL))) {
1111                 mutex_unlock(&jfs_log_mutex);
1112                 return -ENOMEM;
1113         }
1114         INIT_LIST_HEAD(&log->sb_list);
1115         init_waitqueue_head(&log->syncwait);
1116
1117         /*
1118          *      external log as separate logical volume
1119          *
1120          * file systems to log may have n-to-1 relationship;
1121          */
1122
1123         bdev = open_by_devnum(sbi->logdev, FMODE_READ|FMODE_WRITE);
1124         if (IS_ERR(bdev)) {
1125                 rc = -PTR_ERR(bdev);
1126                 goto free;
1127         }
1128
1129         if ((rc = bd_claim(bdev, log))) {
1130                 goto close;
1131         }
1132
1133         log->bdev = bdev;
1134         memcpy(log->uuid, sbi->loguuid, sizeof(log->uuid));
1135
1136         /*
1137          * initialize log:
1138          */
1139         if ((rc = lmLogInit(log)))
1140                 goto unclaim;
1141
1142         list_add(&log->journal_list, &jfs_external_logs);
1143
1144         /*
1145          * add file system to log active file system list
1146          */
1147         if ((rc = lmLogFileSystem(log, sbi, 1)))
1148                 goto shutdown;
1149
1150 journal_found:
1151         LOG_LOCK(log);
1152         list_add(&sbi->log_list, &log->sb_list);
1153         sbi->log = log;
1154         LOG_UNLOCK(log);
1155
1156         mutex_unlock(&jfs_log_mutex);
1157         return 0;
1158
1159         /*
1160          *      unwind on error
1161          */
1162       shutdown:         /* unwind lbmLogInit() */
1163         list_del(&log->journal_list);
1164         lbmLogShutdown(log);
1165
1166       unclaim:
1167         bd_release(bdev);
1168
1169       close:            /* close external log device */
1170         blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1171
1172       free:             /* free log descriptor */
1173         mutex_unlock(&jfs_log_mutex);
1174         kfree(log);
1175
1176         jfs_warn("lmLogOpen: exit(%d)", rc);
1177         return rc;
1178 }
1179
1180 static int open_inline_log(struct super_block *sb)
1181 {
1182         struct jfs_log *log;
1183         int rc;
1184
1185         if (!(log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL)))
1186                 return -ENOMEM;
1187         INIT_LIST_HEAD(&log->sb_list);
1188         init_waitqueue_head(&log->syncwait);
1189
1190         set_bit(log_INLINELOG, &log->flag);
1191         log->bdev = sb->s_bdev;
1192         log->base = addressPXD(&JFS_SBI(sb)->logpxd);
1193         log->size = lengthPXD(&JFS_SBI(sb)->logpxd) >>
1194             (L2LOGPSIZE - sb->s_blocksize_bits);
1195         log->l2bsize = sb->s_blocksize_bits;
1196         ASSERT(L2LOGPSIZE >= sb->s_blocksize_bits);
1197
1198         /*
1199          * initialize log.
1200          */
1201         if ((rc = lmLogInit(log))) {
1202                 kfree(log);
1203                 jfs_warn("lmLogOpen: exit(%d)", rc);
1204                 return rc;
1205         }
1206
1207         list_add(&JFS_SBI(sb)->log_list, &log->sb_list);
1208         JFS_SBI(sb)->log = log;
1209
1210         return rc;
1211 }
1212
1213 static int open_dummy_log(struct super_block *sb)
1214 {
1215         int rc;
1216
1217         mutex_lock(&jfs_log_mutex);
1218         if (!dummy_log) {
1219                 dummy_log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL);
1220                 if (!dummy_log) {
1221                         mutex_unlock(&jfs_log_mutex);
1222                         return -ENOMEM;
1223                 }
1224                 INIT_LIST_HEAD(&dummy_log->sb_list);
1225                 init_waitqueue_head(&dummy_log->syncwait);
1226                 dummy_log->no_integrity = 1;
1227                 /* Make up some stuff */
1228                 dummy_log->base = 0;
1229                 dummy_log->size = 1024;
1230                 rc = lmLogInit(dummy_log);
1231                 if (rc) {
1232                         kfree(dummy_log);
1233                         dummy_log = NULL;
1234                         mutex_unlock(&jfs_log_mutex);
1235                         return rc;
1236                 }
1237         }
1238
1239         LOG_LOCK(dummy_log);
1240         list_add(&JFS_SBI(sb)->log_list, &dummy_log->sb_list);
1241         JFS_SBI(sb)->log = dummy_log;
1242         LOG_UNLOCK(dummy_log);
1243         mutex_unlock(&jfs_log_mutex);
1244
1245         return 0;
1246 }
1247
1248 /*
1249  * NAME:        lmLogInit()
1250  *
1251  * FUNCTION:    log initialization at first log open.
1252  *
1253  *      logredo() (or logformat()) should have been run previously.
1254  *      initialize the log from log superblock.
1255  *      set the log state in the superblock to LOGMOUNT and
1256  *      write SYNCPT log record.
1257  *
1258  * PARAMETER:   log     - log structure
1259  *
1260  * RETURN:      0       - if ok
1261  *              -EINVAL - bad log magic number or superblock dirty
1262  *              error returned from logwait()
1263  *
1264  * serialization: single first open thread
1265  */
1266 int lmLogInit(struct jfs_log * log)
1267 {
1268         int rc = 0;
1269         struct lrd lrd;
1270         struct logsuper *logsuper;
1271         struct lbuf *bpsuper;
1272         struct lbuf *bp;
1273         struct logpage *lp;
1274         int lsn = 0;
1275
1276         jfs_info("lmLogInit: log:0x%p", log);
1277
1278         /* initialize the group commit serialization lock */
1279         LOGGC_LOCK_INIT(log);
1280
1281         /* allocate/initialize the log write serialization lock */
1282         LOG_LOCK_INIT(log);
1283
1284         LOGSYNC_LOCK_INIT(log);
1285
1286         INIT_LIST_HEAD(&log->synclist);
1287
1288         INIT_LIST_HEAD(&log->cqueue);
1289         log->flush_tblk = NULL;
1290
1291         log->count = 0;
1292
1293         /*
1294          * initialize log i/o
1295          */
1296         if ((rc = lbmLogInit(log)))
1297                 return rc;
1298
1299         if (!test_bit(log_INLINELOG, &log->flag))
1300                 log->l2bsize = L2LOGPSIZE;
1301
1302         /* check for disabled journaling to disk */
1303         if (log->no_integrity) {
1304                 /*
1305                  * Journal pages will still be filled.  When the time comes
1306                  * to actually do the I/O, the write is not done, and the
1307                  * endio routine is called directly.
1308                  */
1309                 bp = lbmAllocate(log , 0);
1310                 log->bp = bp;
1311                 bp->l_pn = bp->l_eor = 0;
1312         } else {
1313                 /*
1314                  * validate log superblock
1315                  */
1316                 if ((rc = lbmRead(log, 1, &bpsuper)))
1317                         goto errout10;
1318
1319                 logsuper = (struct logsuper *) bpsuper->l_ldata;
1320
1321                 if (logsuper->magic != cpu_to_le32(LOGMAGIC)) {
1322                         jfs_warn("*** Log Format Error ! ***");
1323                         rc = -EINVAL;
1324                         goto errout20;
1325                 }
1326
1327                 /* logredo() should have been run successfully. */
1328                 if (logsuper->state != cpu_to_le32(LOGREDONE)) {
1329                         jfs_warn("*** Log Is Dirty ! ***");
1330                         rc = -EINVAL;
1331                         goto errout20;
1332                 }
1333
1334                 /* initialize log from log superblock */
1335                 if (test_bit(log_INLINELOG,&log->flag)) {
1336                         if (log->size != le32_to_cpu(logsuper->size)) {
1337                                 rc = -EINVAL;
1338                                 goto errout20;
1339                         }
1340                         jfs_info("lmLogInit: inline log:0x%p base:0x%Lx "
1341                                  "size:0x%x", log,
1342                                  (unsigned long long) log->base, log->size);
1343                 } else {
1344                         if (memcmp(logsuper->uuid, log->uuid, 16)) {
1345                                 jfs_warn("wrong uuid on JFS log device");
1346                                 goto errout20;
1347                         }
1348                         log->size = le32_to_cpu(logsuper->size);
1349                         log->l2bsize = le32_to_cpu(logsuper->l2bsize);
1350                         jfs_info("lmLogInit: external log:0x%p base:0x%Lx "
1351                                  "size:0x%x", log,
1352                                  (unsigned long long) log->base, log->size);
1353                 }
1354
1355                 log->page = le32_to_cpu(logsuper->end) / LOGPSIZE;
1356                 log->eor = le32_to_cpu(logsuper->end) - (LOGPSIZE * log->page);
1357
1358                 /*
1359                  * initialize for log append write mode
1360                  */
1361                 /* establish current/end-of-log page/buffer */
1362                 if ((rc = lbmRead(log, log->page, &bp)))
1363                         goto errout20;
1364
1365                 lp = (struct logpage *) bp->l_ldata;
1366
1367                 jfs_info("lmLogInit: lsn:0x%x page:%d eor:%d:%d",
1368                          le32_to_cpu(logsuper->end), log->page, log->eor,
1369                          le16_to_cpu(lp->h.eor));
1370
1371                 log->bp = bp;
1372                 bp->l_pn = log->page;
1373                 bp->l_eor = log->eor;
1374
1375                 /* if current page is full, move on to next page */
1376                 if (log->eor >= LOGPSIZE - LOGPTLRSIZE)
1377                         lmNextPage(log);
1378
1379                 /*
1380                  * initialize log syncpoint
1381                  */
1382                 /*
1383                  * write the first SYNCPT record with syncpoint = 0
1384                  * (i.e., log redo up to HERE !);
1385                  * remove current page from lbm write queue at end of pageout
1386                  * (to write log superblock update), but do not release to
1387                  * freelist;
1388                  */
1389                 lrd.logtid = 0;
1390                 lrd.backchain = 0;
1391                 lrd.type = cpu_to_le16(LOG_SYNCPT);
1392                 lrd.length = 0;
1393                 lrd.log.syncpt.sync = 0;
1394                 lsn = lmWriteRecord(log, NULL, &lrd, NULL);
1395                 bp = log->bp;
1396                 bp->l_ceor = bp->l_eor;
1397                 lp = (struct logpage *) bp->l_ldata;
1398                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
1399                 lbmWrite(log, bp, lbmWRITE | lbmSYNC, 0);
1400                 if ((rc = lbmIOWait(bp, 0)))
1401                         goto errout30;
1402
1403                 /*
1404                  * update/write superblock
1405                  */
1406                 logsuper->state = cpu_to_le32(LOGMOUNT);
1407                 log->serial = le32_to_cpu(logsuper->serial) + 1;
1408                 logsuper->serial = cpu_to_le32(log->serial);
1409                 lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1410                 if ((rc = lbmIOWait(bpsuper, lbmFREE)))
1411                         goto errout30;
1412         }
1413
1414         /* initialize logsync parameters */
1415         log->logsize = (log->size - 2) << L2LOGPSIZE;
1416         log->lsn = lsn;
1417         log->syncpt = lsn;
1418         log->sync = log->syncpt;
1419         log->nextsync = LOGSYNC_DELTA(log->logsize);
1420
1421         jfs_info("lmLogInit: lsn:0x%x syncpt:0x%x sync:0x%x",
1422                  log->lsn, log->syncpt, log->sync);
1423
1424         /*
1425          * initialize for lazy/group commit
1426          */
1427         log->clsn = lsn;
1428
1429         return 0;
1430
1431         /*
1432          *      unwind on error
1433          */
1434       errout30:         /* release log page */
1435         log->wqueue = NULL;
1436         bp->l_wqnext = NULL;
1437         lbmFree(bp);
1438
1439       errout20:         /* release log superblock */
1440         lbmFree(bpsuper);
1441
1442       errout10:         /* unwind lbmLogInit() */
1443         lbmLogShutdown(log);
1444
1445         jfs_warn("lmLogInit: exit(%d)", rc);
1446         return rc;
1447 }
1448
1449
1450 /*
1451  * NAME:        lmLogClose()
1452  *
1453  * FUNCTION:    remove file system <ipmnt> from active list of log <iplog>
1454  *              and close it on last close.
1455  *
1456  * PARAMETER:   sb      - superblock
1457  *
1458  * RETURN:      errors from subroutines
1459  *
1460  * serialization:
1461  */
1462 int lmLogClose(struct super_block *sb)
1463 {
1464         struct jfs_sb_info *sbi = JFS_SBI(sb);
1465         struct jfs_log *log = sbi->log;
1466         struct block_device *bdev;
1467         int rc = 0;
1468
1469         jfs_info("lmLogClose: log:0x%p", log);
1470
1471         mutex_lock(&jfs_log_mutex);
1472         LOG_LOCK(log);
1473         list_del(&sbi->log_list);
1474         LOG_UNLOCK(log);
1475         sbi->log = NULL;
1476
1477         /*
1478          * We need to make sure all of the "written" metapages
1479          * actually make it to disk
1480          */
1481         sync_blockdev(sb->s_bdev);
1482
1483         if (test_bit(log_INLINELOG, &log->flag)) {
1484                 /*
1485                  *      in-line log in host file system
1486                  */
1487                 rc = lmLogShutdown(log);
1488                 kfree(log);
1489                 goto out;
1490         }
1491
1492         if (!log->no_integrity)
1493                 lmLogFileSystem(log, sbi, 0);
1494
1495         if (!list_empty(&log->sb_list))
1496                 goto out;
1497
1498         /*
1499          * TODO: ensure that the dummy_log is in a state to allow
1500          * lbmLogShutdown to deallocate all the buffers and call
1501          * kfree against dummy_log.  For now, leave dummy_log & its
1502          * buffers in memory, and resuse if another no-integrity mount
1503          * is requested.
1504          */
1505         if (log->no_integrity)
1506                 goto out;
1507
1508         /*
1509          *      external log as separate logical volume
1510          */
1511         list_del(&log->journal_list);
1512         bdev = log->bdev;
1513         rc = lmLogShutdown(log);
1514
1515         bd_release(bdev);
1516         blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1517
1518         kfree(log);
1519
1520       out:
1521         mutex_unlock(&jfs_log_mutex);
1522         jfs_info("lmLogClose: exit(%d)", rc);
1523         return rc;
1524 }
1525
1526
1527 /*
1528  * NAME:        jfs_flush_journal()
1529  *
1530  * FUNCTION:    initiate write of any outstanding transactions to the journal
1531  *              and optionally wait until they are all written to disk
1532  *
1533  *              wait == 0  flush until latest txn is committed, don't wait
1534  *              wait == 1  flush until latest txn is committed, wait
1535  *              wait > 1   flush until all txn's are complete, wait
1536  */
1537 void jfs_flush_journal(struct jfs_log *log, int wait)
1538 {
1539         int i;
1540         struct tblock *target = NULL;
1541
1542         /* jfs_write_inode may call us during read-only mount */
1543         if (!log)
1544                 return;
1545
1546         jfs_info("jfs_flush_journal: log:0x%p wait=%d", log, wait);
1547
1548         LOGGC_LOCK(log);
1549
1550         if (!list_empty(&log->cqueue)) {
1551                 /*
1552                  * This ensures that we will keep writing to the journal as long
1553                  * as there are unwritten commit records
1554                  */
1555                 target = list_entry(log->cqueue.prev, struct tblock, cqueue);
1556
1557                 if (test_bit(log_FLUSH, &log->flag)) {
1558                         /*
1559                          * We're already flushing.
1560                          * if flush_tblk is NULL, we are flushing everything,
1561                          * so leave it that way.  Otherwise, update it to the
1562                          * latest transaction
1563                          */
1564                         if (log->flush_tblk)
1565                                 log->flush_tblk = target;
1566                 } else {
1567                         /* Only flush until latest transaction is committed */
1568                         log->flush_tblk = target;
1569                         set_bit(log_FLUSH, &log->flag);
1570
1571                         /*
1572                          * Initiate I/O on outstanding transactions
1573                          */
1574                         if (!(log->cflag & logGC_PAGEOUT)) {
1575                                 log->cflag |= logGC_PAGEOUT;
1576                                 lmGCwrite(log, 0);
1577                         }
1578                 }
1579         }
1580         if ((wait > 1) || test_bit(log_SYNCBARRIER, &log->flag)) {
1581                 /* Flush until all activity complete */
1582                 set_bit(log_FLUSH, &log->flag);
1583                 log->flush_tblk = NULL;
1584         }
1585
1586         if (wait && target && !(target->flag & tblkGC_COMMITTED)) {
1587                 DECLARE_WAITQUEUE(__wait, current);
1588
1589                 add_wait_queue(&target->gcwait, &__wait);
1590                 set_current_state(TASK_UNINTERRUPTIBLE);
1591                 LOGGC_UNLOCK(log);
1592                 schedule();
1593                 __set_current_state(TASK_RUNNING);
1594                 LOGGC_LOCK(log);
1595                 remove_wait_queue(&target->gcwait, &__wait);
1596         }
1597         LOGGC_UNLOCK(log);
1598
1599         if (wait < 2)
1600                 return;
1601
1602         write_special_inodes(log, filemap_fdatawrite);
1603
1604         /*
1605          * If there was recent activity, we may need to wait
1606          * for the lazycommit thread to catch up
1607          */
1608         if ((!list_empty(&log->cqueue)) || !list_empty(&log->synclist)) {
1609                 for (i = 0; i < 200; i++) {     /* Too much? */
1610                         msleep(250);
1611                         write_special_inodes(log, filemap_fdatawrite);
1612                         if (list_empty(&log->cqueue) &&
1613                             list_empty(&log->synclist))
1614                                 break;
1615                 }
1616         }
1617         assert(list_empty(&log->cqueue));
1618
1619 #ifdef CONFIG_JFS_DEBUG
1620         if (!list_empty(&log->synclist)) {
1621                 struct logsyncblk *lp;
1622
1623                 printk(KERN_ERR "jfs_flush_journal: synclist not empty\n");
1624                 list_for_each_entry(lp, &log->synclist, synclist) {
1625                         if (lp->xflag & COMMIT_PAGE) {
1626                                 struct metapage *mp = (struct metapage *)lp;
1627                                 print_hex_dump(KERN_ERR, "metapage: ",
1628                                                DUMP_PREFIX_ADDRESS, 16, 4,
1629                                                mp, sizeof(struct metapage), 0);
1630                                 print_hex_dump(KERN_ERR, "page: ",
1631                                                DUMP_PREFIX_ADDRESS, 16,
1632                                                sizeof(long), mp->page,
1633                                                sizeof(struct page), 0);
1634                         } else
1635                                 print_hex_dump(KERN_ERR, "tblock:",
1636                                                DUMP_PREFIX_ADDRESS, 16, 4,
1637                                                lp, sizeof(struct tblock), 0);
1638                 }
1639         }
1640 #else
1641         WARN_ON(!list_empty(&log->synclist));
1642 #endif
1643         clear_bit(log_FLUSH, &log->flag);
1644 }
1645
1646 /*
1647  * NAME:        lmLogShutdown()
1648  *
1649  * FUNCTION:    log shutdown at last LogClose().
1650  *
1651  *              write log syncpt record.
1652  *              update super block to set redone flag to 0.
1653  *
1654  * PARAMETER:   log     - log inode
1655  *
1656  * RETURN:      0       - success
1657  *
1658  * serialization: single last close thread
1659  */
1660 int lmLogShutdown(struct jfs_log * log)
1661 {
1662         int rc;
1663         struct lrd lrd;
1664         int lsn;
1665         struct logsuper *logsuper;
1666         struct lbuf *bpsuper;
1667         struct lbuf *bp;
1668         struct logpage *lp;
1669
1670         jfs_info("lmLogShutdown: log:0x%p", log);
1671
1672         jfs_flush_journal(log, 2);
1673
1674         /*
1675          * write the last SYNCPT record with syncpoint = 0
1676          * (i.e., log redo up to HERE !)
1677          */
1678         lrd.logtid = 0;
1679         lrd.backchain = 0;
1680         lrd.type = cpu_to_le16(LOG_SYNCPT);
1681         lrd.length = 0;
1682         lrd.log.syncpt.sync = 0;
1683
1684         lsn = lmWriteRecord(log, NULL, &lrd, NULL);
1685         bp = log->bp;
1686         lp = (struct logpage *) bp->l_ldata;
1687         lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
1688         lbmWrite(log, log->bp, lbmWRITE | lbmRELEASE | lbmSYNC, 0);
1689         lbmIOWait(log->bp, lbmFREE);
1690         log->bp = NULL;
1691
1692         /*
1693          * synchronous update log superblock
1694          * mark log state as shutdown cleanly
1695          * (i.e., Log does not need to be replayed).
1696          */
1697         if ((rc = lbmRead(log, 1, &bpsuper)))
1698                 goto out;
1699
1700         logsuper = (struct logsuper *) bpsuper->l_ldata;
1701         logsuper->state = cpu_to_le32(LOGREDONE);
1702         logsuper->end = cpu_to_le32(lsn);
1703         lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1704         rc = lbmIOWait(bpsuper, lbmFREE);
1705
1706         jfs_info("lmLogShutdown: lsn:0x%x page:%d eor:%d",
1707                  lsn, log->page, log->eor);
1708
1709       out:
1710         /*
1711          * shutdown per log i/o
1712          */
1713         lbmLogShutdown(log);
1714
1715         if (rc) {
1716                 jfs_warn("lmLogShutdown: exit(%d)", rc);
1717         }
1718         return rc;
1719 }
1720
1721
1722 /*
1723  * NAME:        lmLogFileSystem()
1724  *
1725  * FUNCTION:    insert (<activate> = true)/remove (<activate> = false)
1726  *      file system into/from log active file system list.
1727  *
1728  * PARAMETE:    log     - pointer to logs inode.
1729  *              fsdev   - kdev_t of filesystem.
1730  *              serial  - pointer to returned log serial number
1731  *              activate - insert/remove device from active list.
1732  *
1733  * RETURN:      0       - success
1734  *              errors returned by vms_iowait().
1735  */
1736 static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
1737                            int activate)
1738 {
1739         int rc = 0;
1740         int i;
1741         struct logsuper *logsuper;
1742         struct lbuf *bpsuper;
1743         char *uuid = sbi->uuid;
1744
1745         /*
1746          * insert/remove file system device to log active file system list.
1747          */
1748         if ((rc = lbmRead(log, 1, &bpsuper)))
1749                 return rc;
1750
1751         logsuper = (struct logsuper *) bpsuper->l_ldata;
1752         if (activate) {
1753                 for (i = 0; i < MAX_ACTIVE; i++)
1754                         if (!memcmp(logsuper->active[i].uuid, NULL_UUID, 16)) {
1755                                 memcpy(logsuper->active[i].uuid, uuid, 16);
1756                                 sbi->aggregate = i;
1757                                 break;
1758                         }
1759                 if (i == MAX_ACTIVE) {
1760                         jfs_warn("Too many file systems sharing journal!");
1761                         lbmFree(bpsuper);
1762                         return -EMFILE; /* Is there a better rc? */
1763                 }
1764         } else {
1765                 for (i = 0; i < MAX_ACTIVE; i++)
1766                         if (!memcmp(logsuper->active[i].uuid, uuid, 16)) {
1767                                 memcpy(logsuper->active[i].uuid, NULL_UUID, 16);
1768                                 break;
1769                         }
1770                 if (i == MAX_ACTIVE) {
1771                         jfs_warn("Somebody stomped on the journal!");
1772                         lbmFree(bpsuper);
1773                         return -EIO;
1774                 }
1775
1776         }
1777
1778         /*
1779          * synchronous write log superblock:
1780          *
1781          * write sidestream bypassing write queue:
1782          * at file system mount, log super block is updated for
1783          * activation of the file system before any log record
1784          * (MOUNT record) of the file system, and at file system
1785          * unmount, all meta data for the file system has been
1786          * flushed before log super block is updated for deactivation
1787          * of the file system.
1788          */
1789         lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1790         rc = lbmIOWait(bpsuper, lbmFREE);
1791
1792         return rc;
1793 }
1794
1795 /*
1796  *              log buffer manager (lbm)
1797  *              ------------------------
1798  *
1799  * special purpose buffer manager supporting log i/o requirements.
1800  *
1801  * per log write queue:
1802  * log pageout occurs in serial order by fifo write queue and
1803  * restricting to a single i/o in pregress at any one time.
1804  * a circular singly-linked list
1805  * (log->wrqueue points to the tail, and buffers are linked via
1806  * bp->wrqueue field), and
1807  * maintains log page in pageout ot waiting for pageout in serial pageout.
1808  */
1809
1810 /*
1811  *      lbmLogInit()
1812  *
1813  * initialize per log I/O setup at lmLogInit()
1814  */
1815 static int lbmLogInit(struct jfs_log * log)
1816 {                               /* log inode */
1817         int i;
1818         struct lbuf *lbuf;
1819
1820         jfs_info("lbmLogInit: log:0x%p", log);
1821
1822         /* initialize current buffer cursor */
1823         log->bp = NULL;
1824
1825         /* initialize log device write queue */
1826         log->wqueue = NULL;
1827
1828         /*
1829          * Each log has its own buffer pages allocated to it.  These are
1830          * not managed by the page cache.  This ensures that a transaction
1831          * writing to the log does not block trying to allocate a page from
1832          * the page cache (for the log).  This would be bad, since page
1833          * allocation waits on the kswapd thread that may be committing inodes
1834          * which would cause log activity.  Was that clear?  I'm trying to
1835          * avoid deadlock here.
1836          */
1837         init_waitqueue_head(&log->free_wait);
1838
1839         log->lbuf_free = NULL;
1840
1841         for (i = 0; i < LOGPAGES;) {
1842                 char *buffer;
1843                 uint offset;
1844                 struct page *page;
1845
1846                 buffer = (char *) get_zeroed_page(GFP_KERNEL);
1847                 if (buffer == NULL)
1848                         goto error;
1849                 page = virt_to_page(buffer);
1850                 for (offset = 0; offset < PAGE_SIZE; offset += LOGPSIZE) {
1851                         lbuf = kmalloc(sizeof(struct lbuf), GFP_KERNEL);
1852                         if (lbuf == NULL) {
1853                                 if (offset == 0)
1854                                         free_page((unsigned long) buffer);
1855                                 goto error;
1856                         }
1857                         if (offset) /* we already have one reference */
1858                                 get_page(page);
1859                         lbuf->l_offset = offset;
1860                         lbuf->l_ldata = buffer + offset;
1861                         lbuf->l_page = page;
1862                         lbuf->l_log = log;
1863                         init_waitqueue_head(&lbuf->l_ioevent);
1864
1865                         lbuf->l_freelist = log->lbuf_free;
1866                         log->lbuf_free = lbuf;
1867                         i++;
1868                 }
1869         }
1870
1871         return (0);
1872
1873       error:
1874         lbmLogShutdown(log);
1875         return -ENOMEM;
1876 }
1877
1878
1879 /*
1880  *      lbmLogShutdown()
1881  *
1882  * finalize per log I/O setup at lmLogShutdown()
1883  */
1884 static void lbmLogShutdown(struct jfs_log * log)
1885 {
1886         struct lbuf *lbuf;
1887
1888         jfs_info("lbmLogShutdown: log:0x%p", log);
1889
1890         lbuf = log->lbuf_free;
1891         while (lbuf) {
1892                 struct lbuf *next = lbuf->l_freelist;
1893                 __free_page(lbuf->l_page);
1894                 kfree(lbuf);
1895                 lbuf = next;
1896         }
1897 }
1898
1899
1900 /*
1901  *      lbmAllocate()
1902  *
1903  * allocate an empty log buffer
1904  */
1905 static struct lbuf *lbmAllocate(struct jfs_log * log, int pn)
1906 {
1907         struct lbuf *bp;
1908         unsigned long flags;
1909
1910         /*
1911          * recycle from log buffer freelist if any
1912          */
1913         LCACHE_LOCK(flags);
1914         LCACHE_SLEEP_COND(log->free_wait, (bp = log->lbuf_free), flags);
1915         log->lbuf_free = bp->l_freelist;
1916         LCACHE_UNLOCK(flags);
1917
1918         bp->l_flag = 0;
1919
1920         bp->l_wqnext = NULL;
1921         bp->l_freelist = NULL;
1922
1923         bp->l_pn = pn;
1924         bp->l_blkno = log->base + (pn << (L2LOGPSIZE - log->l2bsize));
1925         bp->l_ceor = 0;
1926
1927         return bp;
1928 }
1929
1930
1931 /*
1932  *      lbmFree()
1933  *
1934  * release a log buffer to freelist
1935  */
1936 static void lbmFree(struct lbuf * bp)
1937 {
1938         unsigned long flags;
1939
1940         LCACHE_LOCK(flags);
1941
1942         lbmfree(bp);
1943
1944         LCACHE_UNLOCK(flags);
1945 }
1946
1947 static void lbmfree(struct lbuf * bp)
1948 {
1949         struct jfs_log *log = bp->l_log;
1950
1951         assert(bp->l_wqnext == NULL);
1952
1953         /*
1954          * return the buffer to head of freelist
1955          */
1956         bp->l_freelist = log->lbuf_free;
1957         log->lbuf_free = bp;
1958
1959         wake_up(&log->free_wait);
1960         return;
1961 }
1962
1963
1964 /*
1965  * NAME:        lbmRedrive
1966  *
1967  * FUNCTION:    add a log buffer to the log redrive list
1968  *
1969  * PARAMETER:
1970  *      bp      - log buffer
1971  *
1972  * NOTES:
1973  *      Takes log_redrive_lock.
1974  */
1975 static inline void lbmRedrive(struct lbuf *bp)
1976 {
1977         unsigned long flags;
1978
1979         spin_lock_irqsave(&log_redrive_lock, flags);
1980         bp->l_redrive_next = log_redrive_list;
1981         log_redrive_list = bp;
1982         spin_unlock_irqrestore(&log_redrive_lock, flags);
1983
1984         wake_up_process(jfsIOthread);
1985 }
1986
1987
1988 /*
1989  *      lbmRead()
1990  */
1991 static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
1992 {
1993         struct bio *bio;
1994         struct lbuf *bp;
1995
1996         /*
1997          * allocate a log buffer
1998          */
1999         *bpp = bp = lbmAllocate(log, pn);
2000         jfs_info("lbmRead: bp:0x%p pn:0x%x", bp, pn);
2001
2002         bp->l_flag |= lbmREAD;
2003
2004         bio = bio_alloc(GFP_NOFS, 1);
2005
2006         bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
2007         bio->bi_bdev = log->bdev;
2008         bio->bi_io_vec[0].bv_page = bp->l_page;
2009         bio->bi_io_vec[0].bv_len = LOGPSIZE;
2010         bio->bi_io_vec[0].bv_offset = bp->l_offset;
2011
2012         bio->bi_vcnt = 1;
2013         bio->bi_idx = 0;
2014         bio->bi_size = LOGPSIZE;
2015
2016         bio->bi_end_io = lbmIODone;
2017         bio->bi_private = bp;
2018         submit_bio(READ_SYNC, bio);
2019
2020         wait_event(bp->l_ioevent, (bp->l_flag != lbmREAD));
2021
2022         return 0;
2023 }
2024
2025
2026 /*
2027  *      lbmWrite()
2028  *
2029  * buffer at head of pageout queue stays after completion of
2030  * partial-page pageout and redriven by explicit initiation of
2031  * pageout by caller until full-page pageout is completed and
2032  * released.
2033  *
2034  * device driver i/o done redrives pageout of new buffer at
2035  * head of pageout queue when current buffer at head of pageout
2036  * queue is released at the completion of its full-page pageout.
2037  *
2038  * LOGGC_LOCK() serializes lbmWrite() by lmNextPage() and lmGroupCommit().
2039  * LCACHE_LOCK() serializes xflag between lbmWrite() and lbmIODone()
2040  */
2041 static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag,
2042                      int cant_block)
2043 {
2044         struct lbuf *tail;
2045         unsigned long flags;
2046
2047         jfs_info("lbmWrite: bp:0x%p flag:0x%x pn:0x%x", bp, flag, bp->l_pn);
2048
2049         /* map the logical block address to physical block address */
2050         bp->l_blkno =
2051             log->base + (bp->l_pn << (L2LOGPSIZE - log->l2bsize));
2052
2053         LCACHE_LOCK(flags);             /* disable+lock */
2054
2055         /*
2056          * initialize buffer for device driver
2057          */
2058         bp->l_flag = flag;
2059
2060         /*
2061          *      insert bp at tail of write queue associated with log
2062          *
2063          * (request is either for bp already/currently at head of queue
2064          * or new bp to be inserted at tail)
2065          */
2066         tail = log->wqueue;
2067
2068         /* is buffer not already on write queue ? */
2069         if (bp->l_wqnext == NULL) {
2070                 /* insert at tail of wqueue */
2071                 if (tail == NULL) {
2072                         log->wqueue = bp;
2073                         bp->l_wqnext = bp;
2074                 } else {
2075                         log->wqueue = bp;
2076                         bp->l_wqnext = tail->l_wqnext;
2077                         tail->l_wqnext = bp;
2078                 }
2079
2080                 tail = bp;
2081         }
2082
2083         /* is buffer at head of wqueue and for write ? */
2084         if ((bp != tail->l_wqnext) || !(flag & lbmWRITE)) {
2085                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2086                 return;
2087         }
2088
2089         LCACHE_UNLOCK(flags);   /* unlock+enable */
2090
2091         if (cant_block)
2092                 lbmRedrive(bp);
2093         else if (flag & lbmSYNC)
2094                 lbmStartIO(bp);
2095         else {
2096                 LOGGC_UNLOCK(log);
2097                 lbmStartIO(bp);
2098                 LOGGC_LOCK(log);
2099         }
2100 }
2101
2102
2103 /*
2104  *      lbmDirectWrite()
2105  *
2106  * initiate pageout bypassing write queue for sidestream
2107  * (e.g., log superblock) write;
2108  */
2109 static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag)
2110 {
2111         jfs_info("lbmDirectWrite: bp:0x%p flag:0x%x pn:0x%x",
2112                  bp, flag, bp->l_pn);
2113
2114         /*
2115          * initialize buffer for device driver
2116          */
2117         bp->l_flag = flag | lbmDIRECT;
2118
2119         /* map the logical block address to physical block address */
2120         bp->l_blkno =
2121             log->base + (bp->l_pn << (L2LOGPSIZE - log->l2bsize));
2122
2123         /*
2124          *      initiate pageout of the page
2125          */
2126         lbmStartIO(bp);
2127 }
2128
2129
2130 /*
2131  * NAME:        lbmStartIO()
2132  *
2133  * FUNCTION:    Interface to DD strategy routine
2134  *
2135  * RETURN:      none
2136  *
2137  * serialization: LCACHE_LOCK() is NOT held during log i/o;
2138  */
2139 static void lbmStartIO(struct lbuf * bp)
2140 {
2141         struct bio *bio;
2142         struct jfs_log *log = bp->l_log;
2143
2144         jfs_info("lbmStartIO\n");
2145
2146         bio = bio_alloc(GFP_NOFS, 1);
2147         bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
2148         bio->bi_bdev = log->bdev;
2149         bio->bi_io_vec[0].bv_page = bp->l_page;
2150         bio->bi_io_vec[0].bv_len = LOGPSIZE;
2151         bio->bi_io_vec[0].bv_offset = bp->l_offset;
2152
2153         bio->bi_vcnt = 1;
2154         bio->bi_idx = 0;
2155         bio->bi_size = LOGPSIZE;
2156
2157         bio->bi_end_io = lbmIODone;
2158         bio->bi_private = bp;
2159
2160         /* check if journaling to disk has been disabled */
2161         if (log->no_integrity) {
2162                 bio->bi_size = 0;
2163                 lbmIODone(bio, 0);
2164         } else {
2165                 submit_bio(WRITE_SYNC, bio);
2166                 INCREMENT(lmStat.submitted);
2167         }
2168 }
2169
2170
2171 /*
2172  *      lbmIOWait()
2173  */
2174 static int lbmIOWait(struct lbuf * bp, int flag)
2175 {
2176         unsigned long flags;
2177         int rc = 0;
2178
2179         jfs_info("lbmIOWait1: bp:0x%p flag:0x%x:0x%x", bp, bp->l_flag, flag);
2180
2181         LCACHE_LOCK(flags);             /* disable+lock */
2182
2183         LCACHE_SLEEP_COND(bp->l_ioevent, (bp->l_flag & lbmDONE), flags);
2184
2185         rc = (bp->l_flag & lbmERROR) ? -EIO : 0;
2186
2187         if (flag & lbmFREE)
2188                 lbmfree(bp);
2189
2190         LCACHE_UNLOCK(flags);   /* unlock+enable */
2191
2192         jfs_info("lbmIOWait2: bp:0x%p flag:0x%x:0x%x", bp, bp->l_flag, flag);
2193         return rc;
2194 }
2195
2196 /*
2197  *      lbmIODone()
2198  *
2199  * executed at INTIODONE level
2200  */
2201 static void lbmIODone(struct bio *bio, int error)
2202 {
2203         struct lbuf *bp = bio->bi_private;
2204         struct lbuf *nextbp, *tail;
2205         struct jfs_log *log;
2206         unsigned long flags;
2207
2208         /*
2209          * get back jfs buffer bound to the i/o buffer
2210          */
2211         jfs_info("lbmIODone: bp:0x%p flag:0x%x", bp, bp->l_flag);
2212
2213         LCACHE_LOCK(flags);             /* disable+lock */
2214
2215         bp->l_flag |= lbmDONE;
2216
2217         if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
2218                 bp->l_flag |= lbmERROR;
2219
2220                 jfs_err("lbmIODone: I/O error in JFS log");
2221         }
2222
2223         bio_put(bio);
2224
2225         /*
2226          *      pagein completion
2227          */
2228         if (bp->l_flag & lbmREAD) {
2229                 bp->l_flag &= ~lbmREAD;
2230
2231                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2232
2233                 /* wakeup I/O initiator */
2234                 LCACHE_WAKEUP(&bp->l_ioevent);
2235
2236                 return;
2237         }
2238
2239         /*
2240          *      pageout completion
2241          *
2242          * the bp at the head of write queue has completed pageout.
2243          *
2244          * if single-commit/full-page pageout, remove the current buffer
2245          * from head of pageout queue, and redrive pageout with
2246          * the new buffer at head of pageout queue;
2247          * otherwise, the partial-page pageout buffer stays at
2248          * the head of pageout queue to be redriven for pageout
2249          * by lmGroupCommit() until full-page pageout is completed.
2250          */
2251         bp->l_flag &= ~lbmWRITE;
2252         INCREMENT(lmStat.pagedone);
2253
2254         /* update committed lsn */
2255         log = bp->l_log;
2256         log->clsn = (bp->l_pn << L2LOGPSIZE) + bp->l_ceor;
2257
2258         if (bp->l_flag & lbmDIRECT) {
2259                 LCACHE_WAKEUP(&bp->l_ioevent);
2260                 LCACHE_UNLOCK(flags);
2261                 return;
2262         }
2263
2264         tail = log->wqueue;
2265
2266         /* single element queue */
2267         if (bp == tail) {
2268                 /* remove head buffer of full-page pageout
2269                  * from log device write queue
2270                  */
2271                 if (bp->l_flag & lbmRELEASE) {
2272                         log->wqueue = NULL;
2273                         bp->l_wqnext = NULL;
2274                 }
2275         }
2276         /* multi element queue */
2277         else {
2278                 /* remove head buffer of full-page pageout
2279                  * from log device write queue
2280                  */
2281                 if (bp->l_flag & lbmRELEASE) {
2282                         nextbp = tail->l_wqnext = bp->l_wqnext;
2283                         bp->l_wqnext = NULL;
2284
2285                         /*
2286                          * redrive pageout of next page at head of write queue:
2287                          * redrive next page without any bound tblk
2288                          * (i.e., page w/o any COMMIT records), or
2289                          * first page of new group commit which has been
2290                          * queued after current page (subsequent pageout
2291                          * is performed synchronously, except page without
2292                          * any COMMITs) by lmGroupCommit() as indicated
2293                          * by lbmWRITE flag;
2294                          */
2295                         if (nextbp->l_flag & lbmWRITE) {
2296                                 /*
2297                                  * We can't do the I/O at interrupt time.
2298                                  * The jfsIO thread can do it
2299                                  */
2300                                 lbmRedrive(nextbp);
2301                         }
2302                 }
2303         }
2304
2305         /*
2306          *      synchronous pageout:
2307          *
2308          * buffer has not necessarily been removed from write queue
2309          * (e.g., synchronous write of partial-page with COMMIT):
2310          * leave buffer for i/o initiator to dispose
2311          */
2312         if (bp->l_flag & lbmSYNC) {
2313                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2314
2315                 /* wakeup I/O initiator */
2316                 LCACHE_WAKEUP(&bp->l_ioevent);
2317         }
2318
2319         /*
2320          *      Group Commit pageout:
2321          */
2322         else if (bp->l_flag & lbmGC) {
2323                 LCACHE_UNLOCK(flags);
2324                 lmPostGC(bp);
2325         }
2326
2327         /*
2328          *      asynchronous pageout:
2329          *
2330          * buffer must have been removed from write queue:
2331          * insert buffer at head of freelist where it can be recycled
2332          */
2333         else {
2334                 assert(bp->l_flag & lbmRELEASE);
2335                 assert(bp->l_flag & lbmFREE);
2336                 lbmfree(bp);
2337
2338                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2339         }
2340 }
2341
2342 int jfsIOWait(void *arg)
2343 {
2344         struct lbuf *bp;
2345
2346         do {
2347                 spin_lock_irq(&log_redrive_lock);
2348                 while ((bp = log_redrive_list)) {
2349                         log_redrive_list = bp->l_redrive_next;
2350                         bp->l_redrive_next = NULL;
2351                         spin_unlock_irq(&log_redrive_lock);
2352                         lbmStartIO(bp);
2353                         spin_lock_irq(&log_redrive_lock);
2354                 }
2355
2356                 if (freezing(current)) {
2357                         spin_unlock_irq(&log_redrive_lock);
2358                         refrigerator();
2359                 } else {
2360                         set_current_state(TASK_INTERRUPTIBLE);
2361                         spin_unlock_irq(&log_redrive_lock);
2362                         schedule();
2363                         __set_current_state(TASK_RUNNING);
2364                 }
2365         } while (!kthread_should_stop());
2366
2367         jfs_info("jfsIOWait being killed!");
2368         return 0;
2369 }
2370
2371 /*
2372  * NAME:        lmLogFormat()/jfs_logform()
2373  *
2374  * FUNCTION:    format file system log
2375  *
2376  * PARAMETERS:
2377  *      log     - volume log
2378  *      logAddress - start address of log space in FS block
2379  *      logSize - length of log space in FS block;
2380  *
2381  * RETURN:      0       - success
2382  *              -EIO    - i/o error
2383  *
2384  * XXX: We're synchronously writing one page at a time.  This needs to
2385  *      be improved by writing multiple pages at once.
2386  */
2387 int lmLogFormat(struct jfs_log *log, s64 logAddress, int logSize)
2388 {
2389         int rc = -EIO;
2390         struct jfs_sb_info *sbi;
2391         struct logsuper *logsuper;
2392         struct logpage *lp;
2393         int lspn;               /* log sequence page number */
2394         struct lrd *lrd_ptr;
2395         int npages = 0;
2396         struct lbuf *bp;
2397
2398         jfs_info("lmLogFormat: logAddress:%Ld logSize:%d",
2399                  (long long)logAddress, logSize);
2400
2401         sbi = list_entry(log->sb_list.next, struct jfs_sb_info, log_list);
2402
2403         /* allocate a log buffer */
2404         bp = lbmAllocate(log, 1);
2405
2406         npages = logSize >> sbi->l2nbperpage;
2407
2408         /*
2409          *      log space:
2410          *
2411          * page 0 - reserved;
2412          * page 1 - log superblock;
2413          * page 2 - log data page: A SYNC log record is written
2414          *          into this page at logform time;
2415          * pages 3-N - log data page: set to empty log data pages;
2416          */
2417         /*
2418          *      init log superblock: log page 1
2419          */
2420         logsuper = (struct logsuper *) bp->l_ldata;
2421
2422         logsuper->magic = cpu_to_le32(LOGMAGIC);
2423         logsuper->version = cpu_to_le32(LOGVERSION);
2424         logsuper->state = cpu_to_le32(LOGREDONE);
2425         logsuper->flag = cpu_to_le32(sbi->mntflag);     /* ? */
2426         logsuper->size = cpu_to_le32(npages);
2427         logsuper->bsize = cpu_to_le32(sbi->bsize);
2428         logsuper->l2bsize = cpu_to_le32(sbi->l2bsize);
2429         logsuper->end = cpu_to_le32(2 * LOGPSIZE + LOGPHDRSIZE + LOGRDSIZE);
2430
2431         bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2432         bp->l_blkno = logAddress + sbi->nbperpage;
2433         lbmStartIO(bp);
2434         if ((rc = lbmIOWait(bp, 0)))
2435                 goto exit;
2436
2437         /*
2438          *      init pages 2 to npages-1 as log data pages:
2439          *
2440          * log page sequence number (lpsn) initialization:
2441          *
2442          * pn:   0     1     2     3                 n-1
2443          *       +-----+-----+=====+=====+===.....===+=====+
2444          * lspn:             N-1   0     1           N-2
2445          *                   <--- N page circular file ---->
2446          *
2447          * the N (= npages-2) data pages of the log is maintained as
2448          * a circular file for the log records;
2449          * lpsn grows by 1 monotonically as each log page is written
2450          * to the circular file of the log;
2451          * and setLogpage() will not reset the page number even if
2452          * the eor is equal to LOGPHDRSIZE. In order for binary search
2453          * still work in find log end process, we have to simulate the
2454          * log wrap situation at the log format time.
2455          * The 1st log page written will have the highest lpsn. Then
2456          * the succeeding log pages will have ascending order of
2457          * the lspn starting from 0, ... (N-2)
2458          */
2459         lp = (struct logpage *) bp->l_ldata;
2460         /*
2461          * initialize 1st log page to be written: lpsn = N - 1,
2462          * write a SYNCPT log record is written to this page
2463          */
2464         lp->h.page = lp->t.page = cpu_to_le32(npages - 3);
2465         lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE + LOGRDSIZE);
2466
2467         lrd_ptr = (struct lrd *) &lp->data;
2468         lrd_ptr->logtid = 0;
2469         lrd_ptr->backchain = 0;
2470         lrd_ptr->type = cpu_to_le16(LOG_SYNCPT);
2471         lrd_ptr->length = 0;
2472         lrd_ptr->log.syncpt.sync = 0;
2473
2474         bp->l_blkno += sbi->nbperpage;
2475         bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2476         lbmStartIO(bp);
2477         if ((rc = lbmIOWait(bp, 0)))
2478                 goto exit;
2479
2480         /*
2481          *      initialize succeeding log pages: lpsn = 0, 1, ..., (N-2)
2482          */
2483         for (lspn = 0; lspn < npages - 3; lspn++) {
2484                 lp->h.page = lp->t.page = cpu_to_le32(lspn);
2485                 lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
2486
2487                 bp->l_blkno += sbi->nbperpage;
2488                 bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2489                 lbmStartIO(bp);
2490                 if ((rc = lbmIOWait(bp, 0)))
2491                         goto exit;
2492         }
2493
2494         rc = 0;
2495 exit:
2496         /*
2497          *      finalize log
2498          */
2499         /* release the buffer */
2500         lbmFree(bp);
2501
2502         return rc;
2503 }
2504
2505 #ifdef CONFIG_JFS_STATISTICS
2506 static int jfs_lmstats_proc_show(struct seq_file *m, void *v)
2507 {
2508         seq_printf(m,
2509                        "JFS Logmgr stats\n"
2510                        "================\n"
2511                        "commits = %d\n"
2512                        "writes submitted = %d\n"
2513                        "writes completed = %d\n"
2514                        "full pages submitted = %d\n"
2515                        "partial pages submitted = %d\n",
2516                        lmStat.commit,
2517                        lmStat.submitted,
2518                        lmStat.pagedone,
2519                        lmStat.full_page,
2520                        lmStat.partial_page);
2521         return 0;
2522 }
2523
2524 static int jfs_lmstats_proc_open(struct inode *inode, struct file *file)
2525 {
2526         return single_open(file, jfs_lmstats_proc_show, NULL);
2527 }
2528
2529 const struct file_operations jfs_lmstats_proc_fops = {
2530         .owner          = THIS_MODULE,
2531         .open           = jfs_lmstats_proc_open,
2532         .read           = seq_read,
2533         .llseek         = seq_lseek,
2534         .release        = single_release,
2535 };
2536 #endif /* CONFIG_JFS_STATISTICS */