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Linux/fs/jfs/jfs_logmgr.c

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

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