xref: /linux/fs/jfs/jfs_logmgr.c (revision 776cfebb430c7b22c208b1b17add97f354d97cab)
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/smp_lock.h>
66 #include <linux/completion.h>
67 #include <linux/buffer_head.h>		/* for sync_blockdev() */
68 #include <linux/bio.h>
69 #include <linux/suspend.h>
70 #include <linux/delay.h>
71 #include "jfs_incore.h"
72 #include "jfs_filsys.h"
73 #include "jfs_metapage.h"
74 #include "jfs_txnmgr.h"
75 #include "jfs_debug.h"
76 
77 
78 /*
79  * lbuf's ready to be redriven.  Protected by log_redrive_lock (jfsIO thread)
80  */
81 static struct lbuf *log_redrive_list;
82 static DEFINE_SPINLOCK(log_redrive_lock);
83 DECLARE_WAIT_QUEUE_HEAD(jfs_IO_thread_wait);
84 
85 
86 /*
87  *	log read/write serialization (per log)
88  */
89 #define LOG_LOCK_INIT(log)	init_MUTEX(&(log)->loglock)
90 #define LOG_LOCK(log)		down(&((log)->loglock))
91 #define LOG_UNLOCK(log)		up(&((log)->loglock))
92 
93 
94 /*
95  *	log group commit serialization (per log)
96  */
97 
98 #define LOGGC_LOCK_INIT(log)	spin_lock_init(&(log)->gclock)
99 #define LOGGC_LOCK(log)		spin_lock_irq(&(log)->gclock)
100 #define LOGGC_UNLOCK(log)	spin_unlock_irq(&(log)->gclock)
101 #define LOGGC_WAKEUP(tblk)	wake_up_all(&(tblk)->gcwait)
102 
103 /*
104  *	log sync serialization (per log)
105  */
106 #define	LOGSYNC_DELTA(logsize)		min((logsize)/8, 128*LOGPSIZE)
107 #define	LOGSYNC_BARRIER(logsize)	((logsize)/4)
108 /*
109 #define	LOGSYNC_DELTA(logsize)		min((logsize)/4, 256*LOGPSIZE)
110 #define	LOGSYNC_BARRIER(logsize)	((logsize)/2)
111 */
112 
113 
114 /*
115  *	log buffer cache synchronization
116  */
117 static DEFINE_SPINLOCK(jfsLCacheLock);
118 
119 #define	LCACHE_LOCK(flags)	spin_lock_irqsave(&jfsLCacheLock, flags)
120 #define	LCACHE_UNLOCK(flags)	spin_unlock_irqrestore(&jfsLCacheLock, flags)
121 
122 /*
123  * See __SLEEP_COND in jfs_locks.h
124  */
125 #define LCACHE_SLEEP_COND(wq, cond, flags)	\
126 do {						\
127 	if (cond)				\
128 		break;				\
129 	__SLEEP_COND(wq, cond, LCACHE_LOCK(flags), LCACHE_UNLOCK(flags)); \
130 } while (0)
131 
132 #define	LCACHE_WAKEUP(event)	wake_up(event)
133 
134 
135 /*
136  *	lbuf buffer cache (lCache) control
137  */
138 /* log buffer manager pageout control (cumulative, inclusive) */
139 #define	lbmREAD		0x0001
140 #define	lbmWRITE	0x0002	/* enqueue at tail of write queue;
141 				 * init pageout if at head of queue;
142 				 */
143 #define	lbmRELEASE	0x0004	/* remove from write queue
144 				 * at completion of pageout;
145 				 * do not free/recycle it yet:
146 				 * caller will free it;
147 				 */
148 #define	lbmSYNC		0x0008	/* do not return to freelist
149 				 * when removed from write queue;
150 				 */
151 #define lbmFREE		0x0010	/* return to freelist
152 				 * at completion of pageout;
153 				 * the buffer may be recycled;
154 				 */
155 #define	lbmDONE		0x0020
156 #define	lbmERROR	0x0040
157 #define lbmGC		0x0080	/* lbmIODone to perform post-GC processing
158 				 * of log page
159 				 */
160 #define lbmDIRECT	0x0100
161 
162 /*
163  * Global list of active external journals
164  */
165 static LIST_HEAD(jfs_external_logs);
166 static struct jfs_log *dummy_log = NULL;
167 static DECLARE_MUTEX(jfs_log_sem);
168 
169 /*
170  * external references
171  */
172 extern void txLazyUnlock(struct tblock * tblk);
173 extern int jfs_stop_threads;
174 extern struct completion jfsIOwait;
175 extern int jfs_tlocks_low;
176 
177 /*
178  * forward references
179  */
180 static int lmWriteRecord(struct jfs_log * log, struct tblock * tblk,
181 			 struct lrd * lrd, struct tlock * tlck);
182 
183 static int lmNextPage(struct jfs_log * log);
184 static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
185 			   int activate);
186 
187 static int open_inline_log(struct super_block *sb);
188 static int open_dummy_log(struct super_block *sb);
189 static int lbmLogInit(struct jfs_log * log);
190 static void lbmLogShutdown(struct jfs_log * log);
191 static struct lbuf *lbmAllocate(struct jfs_log * log, int);
192 static void lbmFree(struct lbuf * bp);
193 static void lbmfree(struct lbuf * bp);
194 static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp);
195 static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag, int cant_block);
196 static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag);
197 static int lbmIOWait(struct lbuf * bp, int flag);
198 static bio_end_io_t lbmIODone;
199 static void lbmStartIO(struct lbuf * bp);
200 static void lmGCwrite(struct jfs_log * log, int cant_block);
201 static int lmLogSync(struct jfs_log * log, int nosyncwait);
202 
203 
204 
205 /*
206  *	statistics
207  */
208 #ifdef CONFIG_JFS_STATISTICS
209 static struct lmStat {
210 	uint commit;		/* # of commit */
211 	uint pagedone;		/* # of page written */
212 	uint submitted;		/* # of pages submitted */
213 	uint full_page;		/* # of full pages submitted */
214 	uint partial_page;	/* # of partial pages submitted */
215 } lmStat;
216 #endif
217 
218 
219 /*
220  * NAME:	lmLog()
221  *
222  * FUNCTION:	write a log record;
223  *
224  * PARAMETER:
225  *
226  * RETURN:	lsn - offset to the next log record to write (end-of-log);
227  *		-1  - error;
228  *
229  * note: todo: log error handler
230  */
231 int lmLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
232 	  struct tlock * tlck)
233 {
234 	int lsn;
235 	int diffp, difft;
236 	struct metapage *mp = NULL;
237 	unsigned long flags;
238 
239 	jfs_info("lmLog: log:0x%p tblk:0x%p, lrd:0x%p tlck:0x%p",
240 		 log, tblk, lrd, tlck);
241 
242 	LOG_LOCK(log);
243 
244 	/* log by (out-of-transaction) JFS ? */
245 	if (tblk == NULL)
246 		goto writeRecord;
247 
248 	/* log from page ? */
249 	if (tlck == NULL ||
250 	    tlck->type & tlckBTROOT || (mp = tlck->mp) == NULL)
251 		goto writeRecord;
252 
253 	/*
254 	 *      initialize/update page/transaction recovery lsn
255 	 */
256 	lsn = log->lsn;
257 
258 	LOGSYNC_LOCK(log, flags);
259 
260 	/*
261 	 * initialize page lsn if first log write of the page
262 	 */
263 	if (mp->lsn == 0) {
264 		mp->log = log;
265 		mp->lsn = lsn;
266 		log->count++;
267 
268 		/* insert page at tail of logsynclist */
269 		list_add_tail(&mp->synclist, &log->synclist);
270 	}
271 
272 	/*
273 	 *      initialize/update lsn of tblock of the page
274 	 *
275 	 * transaction inherits oldest lsn of pages associated
276 	 * with allocation/deallocation of resources (their
277 	 * log records are used to reconstruct allocation map
278 	 * at recovery time: inode for inode allocation map,
279 	 * B+-tree index of extent descriptors for block
280 	 * allocation map);
281 	 * allocation map pages inherit transaction lsn at
282 	 * commit time to allow forwarding log syncpt past log
283 	 * records associated with allocation/deallocation of
284 	 * resources only after persistent map of these map pages
285 	 * have been updated and propagated to home.
286 	 */
287 	/*
288 	 * initialize transaction lsn:
289 	 */
290 	if (tblk->lsn == 0) {
291 		/* inherit lsn of its first page logged */
292 		tblk->lsn = mp->lsn;
293 		log->count++;
294 
295 		/* insert tblock after the page on logsynclist */
296 		list_add(&tblk->synclist, &mp->synclist);
297 	}
298 	/*
299 	 * update transaction lsn:
300 	 */
301 	else {
302 		/* inherit oldest/smallest lsn of page */
303 		logdiff(diffp, mp->lsn, log);
304 		logdiff(difft, tblk->lsn, log);
305 		if (diffp < difft) {
306 			/* update tblock lsn with page lsn */
307 			tblk->lsn = mp->lsn;
308 
309 			/* move tblock after page on logsynclist */
310 			list_move(&tblk->synclist, &mp->synclist);
311 		}
312 	}
313 
314 	LOGSYNC_UNLOCK(log, flags);
315 
316 	/*
317 	 *      write the log record
318 	 */
319       writeRecord:
320 	lsn = lmWriteRecord(log, tblk, lrd, tlck);
321 
322 	/*
323 	 * forward log syncpt if log reached next syncpt trigger
324 	 */
325 	logdiff(diffp, lsn, log);
326 	if (diffp >= log->nextsync)
327 		lsn = lmLogSync(log, 0);
328 
329 	/* update end-of-log lsn */
330 	log->lsn = lsn;
331 
332 	LOG_UNLOCK(log);
333 
334 	/* return end-of-log address */
335 	return lsn;
336 }
337 
338 /*
339  * NAME:	lmWriteRecord()
340  *
341  * FUNCTION:	move the log record to current log page
342  *
343  * PARAMETER:	cd	- commit descriptor
344  *
345  * RETURN:	end-of-log address
346  *
347  * serialization: LOG_LOCK() held on entry/exit
348  */
349 static int
350 lmWriteRecord(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
351 	      struct tlock * tlck)
352 {
353 	int lsn = 0;		/* end-of-log address */
354 	struct lbuf *bp;	/* dst log page buffer */
355 	struct logpage *lp;	/* dst log page */
356 	caddr_t dst;		/* destination address in log page */
357 	int dstoffset;		/* end-of-log offset in log page */
358 	int freespace;		/* free space in log page */
359 	caddr_t p;		/* src meta-data page */
360 	caddr_t src;
361 	int srclen;
362 	int nbytes;		/* number of bytes to move */
363 	int i;
364 	int len;
365 	struct linelock *linelock;
366 	struct lv *lv;
367 	struct lvd *lvd;
368 	int l2linesize;
369 
370 	len = 0;
371 
372 	/* retrieve destination log page to write */
373 	bp = (struct lbuf *) log->bp;
374 	lp = (struct logpage *) bp->l_ldata;
375 	dstoffset = log->eor;
376 
377 	/* any log data to write ? */
378 	if (tlck == NULL)
379 		goto moveLrd;
380 
381 	/*
382 	 *      move log record data
383 	 */
384 	/* retrieve source meta-data page to log */
385 	if (tlck->flag & tlckPAGELOCK) {
386 		p = (caddr_t) (tlck->mp->data);
387 		linelock = (struct linelock *) & tlck->lock;
388 	}
389 	/* retrieve source in-memory inode to log */
390 	else if (tlck->flag & tlckINODELOCK) {
391 		if (tlck->type & tlckDTREE)
392 			p = (caddr_t) &JFS_IP(tlck->ip)->i_dtroot;
393 		else
394 			p = (caddr_t) &JFS_IP(tlck->ip)->i_xtroot;
395 		linelock = (struct linelock *) & tlck->lock;
396 	}
397 #ifdef	_JFS_WIP
398 	else if (tlck->flag & tlckINLINELOCK) {
399 
400 		inlinelock = (struct inlinelock *) & tlck;
401 		p = (caddr_t) & inlinelock->pxd;
402 		linelock = (struct linelock *) & tlck;
403 	}
404 #endif				/* _JFS_WIP */
405 	else {
406 		jfs_err("lmWriteRecord: UFO tlck:0x%p", tlck);
407 		return 0;	/* Probably should trap */
408 	}
409 	l2linesize = linelock->l2linesize;
410 
411       moveData:
412 	ASSERT(linelock->index <= linelock->maxcnt);
413 
414 	lv = linelock->lv;
415 	for (i = 0; i < linelock->index; i++, lv++) {
416 		if (lv->length == 0)
417 			continue;
418 
419 		/* is page full ? */
420 		if (dstoffset >= LOGPSIZE - LOGPTLRSIZE) {
421 			/* page become full: move on to next page */
422 			lmNextPage(log);
423 
424 			bp = log->bp;
425 			lp = (struct logpage *) bp->l_ldata;
426 			dstoffset = LOGPHDRSIZE;
427 		}
428 
429 		/*
430 		 * move log vector data
431 		 */
432 		src = (u8 *) p + (lv->offset << l2linesize);
433 		srclen = lv->length << l2linesize;
434 		len += srclen;
435 		while (srclen > 0) {
436 			freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
437 			nbytes = min(freespace, srclen);
438 			dst = (caddr_t) lp + dstoffset;
439 			memcpy(dst, src, nbytes);
440 			dstoffset += nbytes;
441 
442 			/* is page not full ? */
443 			if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
444 				break;
445 
446 			/* page become full: move on to next page */
447 			lmNextPage(log);
448 
449 			bp = (struct lbuf *) log->bp;
450 			lp = (struct logpage *) bp->l_ldata;
451 			dstoffset = LOGPHDRSIZE;
452 
453 			srclen -= nbytes;
454 			src += nbytes;
455 		}
456 
457 		/*
458 		 * move log vector descriptor
459 		 */
460 		len += 4;
461 		lvd = (struct lvd *) ((caddr_t) lp + dstoffset);
462 		lvd->offset = cpu_to_le16(lv->offset);
463 		lvd->length = cpu_to_le16(lv->length);
464 		dstoffset += 4;
465 		jfs_info("lmWriteRecord: lv offset:%d length:%d",
466 			 lv->offset, lv->length);
467 	}
468 
469 	if ((i = linelock->next)) {
470 		linelock = (struct linelock *) lid_to_tlock(i);
471 		goto moveData;
472 	}
473 
474 	/*
475 	 *      move log record descriptor
476 	 */
477       moveLrd:
478 	lrd->length = cpu_to_le16(len);
479 
480 	src = (caddr_t) lrd;
481 	srclen = LOGRDSIZE;
482 
483 	while (srclen > 0) {
484 		freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
485 		nbytes = min(freespace, srclen);
486 		dst = (caddr_t) lp + dstoffset;
487 		memcpy(dst, src, nbytes);
488 
489 		dstoffset += nbytes;
490 		srclen -= nbytes;
491 
492 		/* are there more to move than freespace of page ? */
493 		if (srclen)
494 			goto pageFull;
495 
496 		/*
497 		 * end of log record descriptor
498 		 */
499 
500 		/* update last log record eor */
501 		log->eor = dstoffset;
502 		bp->l_eor = dstoffset;
503 		lsn = (log->page << L2LOGPSIZE) + dstoffset;
504 
505 		if (lrd->type & cpu_to_le16(LOG_COMMIT)) {
506 			tblk->clsn = lsn;
507 			jfs_info("wr: tclsn:0x%x, beor:0x%x", tblk->clsn,
508 				 bp->l_eor);
509 
510 			INCREMENT(lmStat.commit);	/* # of commit */
511 
512 			/*
513 			 * enqueue tblock for group commit:
514 			 *
515 			 * enqueue tblock of non-trivial/synchronous COMMIT
516 			 * at tail of group commit queue
517 			 * (trivial/asynchronous COMMITs are ignored by
518 			 * group commit.)
519 			 */
520 			LOGGC_LOCK(log);
521 
522 			/* init tblock gc state */
523 			tblk->flag = tblkGC_QUEUE;
524 			tblk->bp = log->bp;
525 			tblk->pn = log->page;
526 			tblk->eor = log->eor;
527 
528 			/* enqueue transaction to commit queue */
529 			list_add_tail(&tblk->cqueue, &log->cqueue);
530 
531 			LOGGC_UNLOCK(log);
532 		}
533 
534 		jfs_info("lmWriteRecord: lrd:0x%04x bp:0x%p pn:%d eor:0x%x",
535 			le16_to_cpu(lrd->type), log->bp, log->page, dstoffset);
536 
537 		/* page not full ? */
538 		if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
539 			return lsn;
540 
541 	      pageFull:
542 		/* page become full: move on to next page */
543 		lmNextPage(log);
544 
545 		bp = (struct lbuf *) log->bp;
546 		lp = (struct logpage *) bp->l_ldata;
547 		dstoffset = LOGPHDRSIZE;
548 		src += nbytes;
549 	}
550 
551 	return lsn;
552 }
553 
554 
555 /*
556  * NAME:	lmNextPage()
557  *
558  * FUNCTION:	write current page and allocate next page.
559  *
560  * PARAMETER:	log
561  *
562  * RETURN:	0
563  *
564  * serialization: LOG_LOCK() held on entry/exit
565  */
566 static int lmNextPage(struct jfs_log * log)
567 {
568 	struct logpage *lp;
569 	int lspn;		/* log sequence page number */
570 	int pn;			/* current page number */
571 	struct lbuf *bp;
572 	struct lbuf *nextbp;
573 	struct tblock *tblk;
574 
575 	/* get current log page number and log sequence page number */
576 	pn = log->page;
577 	bp = log->bp;
578 	lp = (struct logpage *) bp->l_ldata;
579 	lspn = le32_to_cpu(lp->h.page);
580 
581 	LOGGC_LOCK(log);
582 
583 	/*
584 	 *      write or queue the full page at the tail of write queue
585 	 */
586 	/* get the tail tblk on commit queue */
587 	if (list_empty(&log->cqueue))
588 		tblk = NULL;
589 	else
590 		tblk = list_entry(log->cqueue.prev, struct tblock, cqueue);
591 
592 	/* every tblk who has COMMIT record on the current page,
593 	 * and has not been committed, must be on commit queue
594 	 * since tblk is queued at commit queueu at the time
595 	 * of writing its COMMIT record on the page before
596 	 * page becomes full (even though the tblk thread
597 	 * who wrote COMMIT record may have been suspended
598 	 * currently);
599 	 */
600 
601 	/* is page bound with outstanding tail tblk ? */
602 	if (tblk && tblk->pn == pn) {
603 		/* mark tblk for end-of-page */
604 		tblk->flag |= tblkGC_EOP;
605 
606 		if (log->cflag & logGC_PAGEOUT) {
607 			/* if page is not already on write queue,
608 			 * just enqueue (no lbmWRITE to prevent redrive)
609 			 * buffer to wqueue to ensure correct serial order
610 			 * of the pages since log pages will be added
611 			 * continuously
612 			 */
613 			if (bp->l_wqnext == NULL)
614 				lbmWrite(log, bp, 0, 0);
615 		} else {
616 			/*
617 			 * No current GC leader, initiate group commit
618 			 */
619 			log->cflag |= logGC_PAGEOUT;
620 			lmGCwrite(log, 0);
621 		}
622 	}
623 	/* page is not bound with outstanding tblk:
624 	 * init write or mark it to be redriven (lbmWRITE)
625 	 */
626 	else {
627 		/* finalize the page */
628 		bp->l_ceor = bp->l_eor;
629 		lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
630 		lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE, 0);
631 	}
632 	LOGGC_UNLOCK(log);
633 
634 	/*
635 	 *      allocate/initialize next page
636 	 */
637 	/* if log wraps, the first data page of log is 2
638 	 * (0 never used, 1 is superblock).
639 	 */
640 	log->page = (pn == log->size - 1) ? 2 : pn + 1;
641 	log->eor = LOGPHDRSIZE;	/* ? valid page empty/full at logRedo() */
642 
643 	/* allocate/initialize next log page buffer */
644 	nextbp = lbmAllocate(log, log->page);
645 	nextbp->l_eor = log->eor;
646 	log->bp = nextbp;
647 
648 	/* initialize next log page */
649 	lp = (struct logpage *) nextbp->l_ldata;
650 	lp->h.page = lp->t.page = cpu_to_le32(lspn + 1);
651 	lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
652 
653 	return 0;
654 }
655 
656 
657 /*
658  * NAME:	lmGroupCommit()
659  *
660  * FUNCTION:	group commit
661  *	initiate pageout of the pages with COMMIT in the order of
662  *	page number - redrive pageout of the page at the head of
663  *	pageout queue until full page has been written.
664  *
665  * RETURN:
666  *
667  * NOTE:
668  *	LOGGC_LOCK serializes log group commit queue, and
669  *	transaction blocks on the commit queue.
670  *	N.B. LOG_LOCK is NOT held during lmGroupCommit().
671  */
672 int lmGroupCommit(struct jfs_log * log, struct tblock * tblk)
673 {
674 	int rc = 0;
675 
676 	LOGGC_LOCK(log);
677 
678 	/* group committed already ? */
679 	if (tblk->flag & tblkGC_COMMITTED) {
680 		if (tblk->flag & tblkGC_ERROR)
681 			rc = -EIO;
682 
683 		LOGGC_UNLOCK(log);
684 		return rc;
685 	}
686 	jfs_info("lmGroup Commit: tblk = 0x%p, gcrtc = %d", tblk, log->gcrtc);
687 
688 	if (tblk->xflag & COMMIT_LAZY)
689 		tblk->flag |= tblkGC_LAZY;
690 
691 	if ((!(log->cflag & logGC_PAGEOUT)) && (!list_empty(&log->cqueue)) &&
692 	    (!(tblk->xflag & COMMIT_LAZY) || test_bit(log_FLUSH, &log->flag)
693 	     || jfs_tlocks_low)) {
694 		/*
695 		 * No pageout in progress
696 		 *
697 		 * start group commit as its group leader.
698 		 */
699 		log->cflag |= logGC_PAGEOUT;
700 
701 		lmGCwrite(log, 0);
702 	}
703 
704 	if (tblk->xflag & COMMIT_LAZY) {
705 		/*
706 		 * Lazy transactions can leave now
707 		 */
708 		LOGGC_UNLOCK(log);
709 		return 0;
710 	}
711 
712 	/* lmGCwrite gives up LOGGC_LOCK, check again */
713 
714 	if (tblk->flag & tblkGC_COMMITTED) {
715 		if (tblk->flag & tblkGC_ERROR)
716 			rc = -EIO;
717 
718 		LOGGC_UNLOCK(log);
719 		return rc;
720 	}
721 
722 	/* upcount transaction waiting for completion
723 	 */
724 	log->gcrtc++;
725 	tblk->flag |= tblkGC_READY;
726 
727 	__SLEEP_COND(tblk->gcwait, (tblk->flag & tblkGC_COMMITTED),
728 		     LOGGC_LOCK(log), LOGGC_UNLOCK(log));
729 
730 	/* removed from commit queue */
731 	if (tblk->flag & tblkGC_ERROR)
732 		rc = -EIO;
733 
734 	LOGGC_UNLOCK(log);
735 	return rc;
736 }
737 
738 /*
739  * NAME:	lmGCwrite()
740  *
741  * FUNCTION:	group commit write
742  *	initiate write of log page, building a group of all transactions
743  *	with commit records on that page.
744  *
745  * RETURN:	None
746  *
747  * NOTE:
748  *	LOGGC_LOCK must be held by caller.
749  *	N.B. LOG_LOCK is NOT held during lmGroupCommit().
750  */
751 static void lmGCwrite(struct jfs_log * log, int cant_write)
752 {
753 	struct lbuf *bp;
754 	struct logpage *lp;
755 	int gcpn;		/* group commit page number */
756 	struct tblock *tblk;
757 	struct tblock *xtblk = NULL;
758 
759 	/*
760 	 * build the commit group of a log page
761 	 *
762 	 * scan commit queue and make a commit group of all
763 	 * transactions with COMMIT records on the same log page.
764 	 */
765 	/* get the head tblk on the commit queue */
766 	gcpn = list_entry(log->cqueue.next, struct tblock, cqueue)->pn;
767 
768 	list_for_each_entry(tblk, &log->cqueue, cqueue) {
769 		if (tblk->pn != gcpn)
770 			break;
771 
772 		xtblk = tblk;
773 
774 		/* state transition: (QUEUE, READY) -> COMMIT */
775 		tblk->flag |= tblkGC_COMMIT;
776 	}
777 	tblk = xtblk;		/* last tblk of the page */
778 
779 	/*
780 	 * pageout to commit transactions on the log page.
781 	 */
782 	bp = (struct lbuf *) tblk->bp;
783 	lp = (struct logpage *) bp->l_ldata;
784 	/* is page already full ? */
785 	if (tblk->flag & tblkGC_EOP) {
786 		/* mark page to free at end of group commit of the page */
787 		tblk->flag &= ~tblkGC_EOP;
788 		tblk->flag |= tblkGC_FREE;
789 		bp->l_ceor = bp->l_eor;
790 		lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
791 		lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmGC,
792 			 cant_write);
793 		INCREMENT(lmStat.full_page);
794 	}
795 	/* page is not yet full */
796 	else {
797 		bp->l_ceor = tblk->eor;	/* ? bp->l_ceor = bp->l_eor; */
798 		lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
799 		lbmWrite(log, bp, lbmWRITE | lbmGC, cant_write);
800 		INCREMENT(lmStat.partial_page);
801 	}
802 }
803 
804 /*
805  * NAME:	lmPostGC()
806  *
807  * FUNCTION:	group commit post-processing
808  *	Processes transactions after their commit records have been written
809  *	to disk, redriving log I/O if necessary.
810  *
811  * RETURN:	None
812  *
813  * NOTE:
814  *	This routine is called a interrupt time by lbmIODone
815  */
816 static void lmPostGC(struct lbuf * bp)
817 {
818 	unsigned long flags;
819 	struct jfs_log *log = bp->l_log;
820 	struct logpage *lp;
821 	struct tblock *tblk, *temp;
822 
823 	//LOGGC_LOCK(log);
824 	spin_lock_irqsave(&log->gclock, flags);
825 	/*
826 	 * current pageout of group commit completed.
827 	 *
828 	 * remove/wakeup transactions from commit queue who were
829 	 * group committed with the current log page
830 	 */
831 	list_for_each_entry_safe(tblk, temp, &log->cqueue, cqueue) {
832 		if (!(tblk->flag & tblkGC_COMMIT))
833 			break;
834 		/* if transaction was marked GC_COMMIT then
835 		 * it has been shipped in the current pageout
836 		 * and made it to disk - it is committed.
837 		 */
838 
839 		if (bp->l_flag & lbmERROR)
840 			tblk->flag |= tblkGC_ERROR;
841 
842 		/* remove it from the commit queue */
843 		list_del(&tblk->cqueue);
844 		tblk->flag &= ~tblkGC_QUEUE;
845 
846 		if (tblk == log->flush_tblk) {
847 			/* we can stop flushing the log now */
848 			clear_bit(log_FLUSH, &log->flag);
849 			log->flush_tblk = NULL;
850 		}
851 
852 		jfs_info("lmPostGC: tblk = 0x%p, flag = 0x%x", tblk,
853 			 tblk->flag);
854 
855 		if (!(tblk->xflag & COMMIT_FORCE))
856 			/*
857 			 * Hand tblk over to lazy commit thread
858 			 */
859 			txLazyUnlock(tblk);
860 		else {
861 			/* state transition: COMMIT -> COMMITTED */
862 			tblk->flag |= tblkGC_COMMITTED;
863 
864 			if (tblk->flag & tblkGC_READY)
865 				log->gcrtc--;
866 
867 			LOGGC_WAKEUP(tblk);
868 		}
869 
870 		/* was page full before pageout ?
871 		 * (and this is the last tblk bound with the page)
872 		 */
873 		if (tblk->flag & tblkGC_FREE)
874 			lbmFree(bp);
875 		/* did page become full after pageout ?
876 		 * (and this is the last tblk bound with the page)
877 		 */
878 		else if (tblk->flag & tblkGC_EOP) {
879 			/* finalize the page */
880 			lp = (struct logpage *) bp->l_ldata;
881 			bp->l_ceor = bp->l_eor;
882 			lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
883 			jfs_info("lmPostGC: calling lbmWrite");
884 			lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE,
885 				 1);
886 		}
887 
888 	}
889 
890 	/* are there any transactions who have entered lnGroupCommit()
891 	 * (whose COMMITs are after that of the last log page written.
892 	 * They are waiting for new group commit (above at (SLEEP 1))
893 	 * or lazy transactions are on a full (queued) log page,
894 	 * select the latest ready transaction as new group leader and
895 	 * wake her up to lead her group.
896 	 */
897 	if ((!list_empty(&log->cqueue)) &&
898 	    ((log->gcrtc > 0) || (tblk->bp->l_wqnext != NULL) ||
899 	     test_bit(log_FLUSH, &log->flag) || jfs_tlocks_low))
900 		/*
901 		 * Call lmGCwrite with new group leader
902 		 */
903 		lmGCwrite(log, 1);
904 
905 	/* no transaction are ready yet (transactions are only just
906 	 * queued (GC_QUEUE) and not entered for group commit yet).
907 	 * the first transaction entering group commit
908 	 * will elect herself as new group leader.
909 	 */
910 	else
911 		log->cflag &= ~logGC_PAGEOUT;
912 
913 	//LOGGC_UNLOCK(log);
914 	spin_unlock_irqrestore(&log->gclock, flags);
915 	return;
916 }
917 
918 /*
919  * NAME:	lmLogSync()
920  *
921  * FUNCTION:	write log SYNCPT record for specified log
922  *	if new sync address is available
923  *	(normally the case if sync() is executed by back-ground
924  *	process).
925  *	if not, explicitly run jfs_blogsync() to initiate
926  *	getting of new sync address.
927  *	calculate new value of i_nextsync which determines when
928  *	this code is called again.
929  *
930  * PARAMETERS:	log	- log structure
931  * 		nosyncwait - 1 if called asynchronously
932  *
933  * RETURN:	0
934  *
935  * serialization: LOG_LOCK() held on entry/exit
936  */
937 static int lmLogSync(struct jfs_log * log, int nosyncwait)
938 {
939 	int logsize;
940 	int written;		/* written since last syncpt */
941 	int free;		/* free space left available */
942 	int delta;		/* additional delta to write normally */
943 	int more;		/* additional write granted */
944 	struct lrd lrd;
945 	int lsn;
946 	struct logsyncblk *lp;
947 	struct jfs_sb_info *sbi;
948 	unsigned long flags;
949 
950 	/* push dirty metapages out to disk */
951 	list_for_each_entry(sbi, &log->sb_list, log_list) {
952 		filemap_flush(sbi->ipbmap->i_mapping);
953 		filemap_flush(sbi->ipimap->i_mapping);
954 		filemap_flush(sbi->direct_inode->i_mapping);
955 	}
956 
957 	/*
958 	 *      forward syncpt
959 	 */
960 	/* if last sync is same as last syncpt,
961 	 * invoke sync point forward processing to update sync.
962 	 */
963 
964 	if (log->sync == log->syncpt) {
965 		LOGSYNC_LOCK(log, flags);
966 		if (list_empty(&log->synclist))
967 			log->sync = log->lsn;
968 		else {
969 			lp = list_entry(log->synclist.next,
970 					struct logsyncblk, synclist);
971 			log->sync = lp->lsn;
972 		}
973 		LOGSYNC_UNLOCK(log, flags);
974 
975 	}
976 
977 	/* if sync is different from last syncpt,
978 	 * write a SYNCPT record with syncpt = sync.
979 	 * reset syncpt = sync
980 	 */
981 	if (log->sync != log->syncpt) {
982 		lrd.logtid = 0;
983 		lrd.backchain = 0;
984 		lrd.type = cpu_to_le16(LOG_SYNCPT);
985 		lrd.length = 0;
986 		lrd.log.syncpt.sync = cpu_to_le32(log->sync);
987 		lsn = lmWriteRecord(log, NULL, &lrd, NULL);
988 
989 		log->syncpt = log->sync;
990 	} else
991 		lsn = log->lsn;
992 
993 	/*
994 	 *      setup next syncpt trigger (SWAG)
995 	 */
996 	logsize = log->logsize;
997 
998 	logdiff(written, lsn, log);
999 	free = logsize - written;
1000 	delta = LOGSYNC_DELTA(logsize);
1001 	more = min(free / 2, delta);
1002 	if (more < 2 * LOGPSIZE) {
1003 		jfs_warn("\n ... Log Wrap ... Log Wrap ... Log Wrap ...\n");
1004 		/*
1005 		 *      log wrapping
1006 		 *
1007 		 * option 1 - panic ? No.!
1008 		 * option 2 - shutdown file systems
1009 		 *            associated with log ?
1010 		 * option 3 - extend log ?
1011 		 */
1012 		/*
1013 		 * option 4 - second chance
1014 		 *
1015 		 * mark log wrapped, and continue.
1016 		 * when all active transactions are completed,
1017 		 * mark log vaild for recovery.
1018 		 * if crashed during invalid state, log state
1019 		 * implies invald log, forcing fsck().
1020 		 */
1021 		/* mark log state log wrap in log superblock */
1022 		/* log->state = LOGWRAP; */
1023 
1024 		/* reset sync point computation */
1025 		log->syncpt = log->sync = lsn;
1026 		log->nextsync = delta;
1027 	} else
1028 		/* next syncpt trigger = written + more */
1029 		log->nextsync = written + more;
1030 
1031 	/* return if lmLogSync() from outside of transaction, e.g., sync() */
1032 	if (nosyncwait)
1033 		return lsn;
1034 
1035 	/* if number of bytes written from last sync point is more
1036 	 * than 1/4 of the log size, stop new transactions from
1037 	 * starting until all current transactions are completed
1038 	 * by setting syncbarrier flag.
1039 	 */
1040 	if (written > LOGSYNC_BARRIER(logsize) && logsize > 32 * LOGPSIZE) {
1041 		set_bit(log_SYNCBARRIER, &log->flag);
1042 		jfs_info("log barrier on: lsn=0x%x syncpt=0x%x", lsn,
1043 			 log->syncpt);
1044 		/*
1045 		 * We may have to initiate group commit
1046 		 */
1047 		jfs_flush_journal(log, 0);
1048 	}
1049 
1050 	return lsn;
1051 }
1052 
1053 /*
1054  * NAME:	jfs_syncpt
1055  *
1056  * FUNCTION:	write log SYNCPT record for specified log
1057  *
1058  * PARAMETERS:	log	- log structure
1059  */
1060 void jfs_syncpt(struct jfs_log *log)
1061 {	LOG_LOCK(log);
1062 	lmLogSync(log, 1);
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 	down(&jfs_log_sem);
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\n");
1098 				up(&jfs_log_sem);
1099 				return -EINVAL;
1100 			}
1101 			/*
1102 			 * add file system to log active file system list
1103 			 */
1104 			if ((rc = lmLogFileSystem(log, sbi, 1))) {
1105 				up(&jfs_log_sem);
1106 				return rc;
1107 			}
1108 			goto journal_found;
1109 		}
1110 	}
1111 
1112 	if (!(log = kmalloc(sizeof(struct jfs_log), GFP_KERNEL))) {
1113 		up(&jfs_log_sem);
1114 		return -ENOMEM;
1115 	}
1116 	memset(log, 0, sizeof(struct jfs_log));
1117 	INIT_LIST_HEAD(&log->sb_list);
1118 	init_waitqueue_head(&log->syncwait);
1119 
1120 	/*
1121 	 *      external log as separate logical volume
1122 	 *
1123 	 * file systems to log may have n-to-1 relationship;
1124 	 */
1125 
1126 	bdev = open_by_devnum(sbi->logdev, FMODE_READ|FMODE_WRITE);
1127 	if (IS_ERR(bdev)) {
1128 		rc = -PTR_ERR(bdev);
1129 		goto free;
1130 	}
1131 
1132 	if ((rc = bd_claim(bdev, log))) {
1133 		goto close;
1134 	}
1135 
1136 	log->bdev = bdev;
1137 	memcpy(log->uuid, sbi->loguuid, sizeof(log->uuid));
1138 
1139 	/*
1140 	 * initialize log:
1141 	 */
1142 	if ((rc = lmLogInit(log)))
1143 		goto unclaim;
1144 
1145 	list_add(&log->journal_list, &jfs_external_logs);
1146 
1147 	/*
1148 	 * add file system to log active file system list
1149 	 */
1150 	if ((rc = lmLogFileSystem(log, sbi, 1)))
1151 		goto shutdown;
1152 
1153 journal_found:
1154 	LOG_LOCK(log);
1155 	list_add(&sbi->log_list, &log->sb_list);
1156 	sbi->log = log;
1157 	LOG_UNLOCK(log);
1158 
1159 	up(&jfs_log_sem);
1160 	return 0;
1161 
1162 	/*
1163 	 *      unwind on error
1164 	 */
1165       shutdown:		/* unwind lbmLogInit() */
1166 	list_del(&log->journal_list);
1167 	lbmLogShutdown(log);
1168 
1169       unclaim:
1170 	bd_release(bdev);
1171 
1172       close:		/* close external log device */
1173 	blkdev_put(bdev);
1174 
1175       free:		/* free log descriptor */
1176 	up(&jfs_log_sem);
1177 	kfree(log);
1178 
1179 	jfs_warn("lmLogOpen: exit(%d)", rc);
1180 	return rc;
1181 }
1182 
1183 static int open_inline_log(struct super_block *sb)
1184 {
1185 	struct jfs_log *log;
1186 	int rc;
1187 
1188 	if (!(log = kmalloc(sizeof(struct jfs_log), GFP_KERNEL)))
1189 		return -ENOMEM;
1190 	memset(log, 0, sizeof(struct jfs_log));
1191 	INIT_LIST_HEAD(&log->sb_list);
1192 	init_waitqueue_head(&log->syncwait);
1193 
1194 	set_bit(log_INLINELOG, &log->flag);
1195 	log->bdev = sb->s_bdev;
1196 	log->base = addressPXD(&JFS_SBI(sb)->logpxd);
1197 	log->size = lengthPXD(&JFS_SBI(sb)->logpxd) >>
1198 	    (L2LOGPSIZE - sb->s_blocksize_bits);
1199 	log->l2bsize = sb->s_blocksize_bits;
1200 	ASSERT(L2LOGPSIZE >= sb->s_blocksize_bits);
1201 
1202 	/*
1203 	 * initialize log.
1204 	 */
1205 	if ((rc = lmLogInit(log))) {
1206 		kfree(log);
1207 		jfs_warn("lmLogOpen: exit(%d)", rc);
1208 		return rc;
1209 	}
1210 
1211 	list_add(&JFS_SBI(sb)->log_list, &log->sb_list);
1212 	JFS_SBI(sb)->log = log;
1213 
1214 	return rc;
1215 }
1216 
1217 static int open_dummy_log(struct super_block *sb)
1218 {
1219 	int rc;
1220 
1221 	down(&jfs_log_sem);
1222 	if (!dummy_log) {
1223 		dummy_log = kmalloc(sizeof(struct jfs_log), GFP_KERNEL);
1224 		if (!dummy_log) {
1225 			up(&jfs_log_sem);
1226 			return -ENOMEM;
1227 		}
1228 		memset(dummy_log, 0, sizeof(struct jfs_log));
1229 		INIT_LIST_HEAD(&dummy_log->sb_list);
1230 		init_waitqueue_head(&dummy_log->syncwait);
1231 		dummy_log->no_integrity = 1;
1232 		/* Make up some stuff */
1233 		dummy_log->base = 0;
1234 		dummy_log->size = 1024;
1235 		rc = lmLogInit(dummy_log);
1236 		if (rc) {
1237 			kfree(dummy_log);
1238 			dummy_log = NULL;
1239 			up(&jfs_log_sem);
1240 			return rc;
1241 		}
1242 	}
1243 
1244 	LOG_LOCK(dummy_log);
1245 	list_add(&JFS_SBI(sb)->log_list, &dummy_log->sb_list);
1246 	JFS_SBI(sb)->log = dummy_log;
1247 	LOG_UNLOCK(dummy_log);
1248 	up(&jfs_log_sem);
1249 
1250 	return 0;
1251 }
1252 
1253 /*
1254  * NAME:	lmLogInit()
1255  *
1256  * FUNCTION:	log initialization at first log open.
1257  *
1258  *	logredo() (or logformat()) should have been run previously.
1259  *	initialize the log from log superblock.
1260  *	set the log state in the superblock to LOGMOUNT and
1261  *	write SYNCPT log record.
1262  *
1263  * PARAMETER:	log	- log structure
1264  *
1265  * RETURN:	0	- if ok
1266  *		-EINVAL	- bad log magic number or superblock dirty
1267  *		error returned from logwait()
1268  *
1269  * serialization: single first open thread
1270  */
1271 int lmLogInit(struct jfs_log * log)
1272 {
1273 	int rc = 0;
1274 	struct lrd lrd;
1275 	struct logsuper *logsuper;
1276 	struct lbuf *bpsuper;
1277 	struct lbuf *bp;
1278 	struct logpage *lp;
1279 	int lsn = 0;
1280 
1281 	jfs_info("lmLogInit: log:0x%p", log);
1282 
1283 	/* initialize the group commit serialization lock */
1284 	LOGGC_LOCK_INIT(log);
1285 
1286 	/* allocate/initialize the log write serialization lock */
1287 	LOG_LOCK_INIT(log);
1288 
1289 	LOGSYNC_LOCK_INIT(log);
1290 
1291 	INIT_LIST_HEAD(&log->synclist);
1292 
1293 	INIT_LIST_HEAD(&log->cqueue);
1294 	log->flush_tblk = NULL;
1295 
1296 	log->count = 0;
1297 
1298 	/*
1299 	 * initialize log i/o
1300 	 */
1301 	if ((rc = lbmLogInit(log)))
1302 		return rc;
1303 
1304 	if (!test_bit(log_INLINELOG, &log->flag))
1305 		log->l2bsize = L2LOGPSIZE;
1306 
1307 	/* check for disabled journaling to disk */
1308 	if (log->no_integrity) {
1309 		/*
1310 		 * Journal pages will still be filled.  When the time comes
1311 		 * to actually do the I/O, the write is not done, and the
1312 		 * endio routine is called directly.
1313 		 */
1314 		bp = lbmAllocate(log , 0);
1315 		log->bp = bp;
1316 		bp->l_pn = bp->l_eor = 0;
1317 	} else {
1318 		/*
1319 		 * validate log superblock
1320 		 */
1321 		if ((rc = lbmRead(log, 1, &bpsuper)))
1322 			goto errout10;
1323 
1324 		logsuper = (struct logsuper *) bpsuper->l_ldata;
1325 
1326 		if (logsuper->magic != cpu_to_le32(LOGMAGIC)) {
1327 			jfs_warn("*** Log Format Error ! ***");
1328 			rc = -EINVAL;
1329 			goto errout20;
1330 		}
1331 
1332 		/* logredo() should have been run successfully. */
1333 		if (logsuper->state != cpu_to_le32(LOGREDONE)) {
1334 			jfs_warn("*** Log Is Dirty ! ***");
1335 			rc = -EINVAL;
1336 			goto errout20;
1337 		}
1338 
1339 		/* initialize log from log superblock */
1340 		if (test_bit(log_INLINELOG,&log->flag)) {
1341 			if (log->size != le32_to_cpu(logsuper->size)) {
1342 				rc = -EINVAL;
1343 				goto errout20;
1344 			}
1345 			jfs_info("lmLogInit: inline log:0x%p base:0x%Lx "
1346 				 "size:0x%x", log,
1347 				 (unsigned long long) log->base, log->size);
1348 		} else {
1349 			if (memcmp(logsuper->uuid, log->uuid, 16)) {
1350 				jfs_warn("wrong uuid on JFS log device");
1351 				goto errout20;
1352 			}
1353 			log->size = le32_to_cpu(logsuper->size);
1354 			log->l2bsize = le32_to_cpu(logsuper->l2bsize);
1355 			jfs_info("lmLogInit: external log:0x%p base:0x%Lx "
1356 				 "size:0x%x", log,
1357 				 (unsigned long long) log->base, log->size);
1358 		}
1359 
1360 		log->page = le32_to_cpu(logsuper->end) / LOGPSIZE;
1361 		log->eor = le32_to_cpu(logsuper->end) - (LOGPSIZE * log->page);
1362 
1363 		/*
1364 		 * initialize for log append write mode
1365 		 */
1366 		/* establish current/end-of-log page/buffer */
1367 		if ((rc = lbmRead(log, log->page, &bp)))
1368 			goto errout20;
1369 
1370 		lp = (struct logpage *) bp->l_ldata;
1371 
1372 		jfs_info("lmLogInit: lsn:0x%x page:%d eor:%d:%d",
1373 			 le32_to_cpu(logsuper->end), log->page, log->eor,
1374 			 le16_to_cpu(lp->h.eor));
1375 
1376 		log->bp = bp;
1377 		bp->l_pn = log->page;
1378 		bp->l_eor = log->eor;
1379 
1380 		/* if current page is full, move on to next page */
1381 		if (log->eor >= LOGPSIZE - LOGPTLRSIZE)
1382 			lmNextPage(log);
1383 
1384 		/*
1385 		 * initialize log syncpoint
1386 		 */
1387 		/*
1388 		 * write the first SYNCPT record with syncpoint = 0
1389 		 * (i.e., log redo up to HERE !);
1390 		 * remove current page from lbm write queue at end of pageout
1391 		 * (to write log superblock update), but do not release to
1392 		 * freelist;
1393 		 */
1394 		lrd.logtid = 0;
1395 		lrd.backchain = 0;
1396 		lrd.type = cpu_to_le16(LOG_SYNCPT);
1397 		lrd.length = 0;
1398 		lrd.log.syncpt.sync = 0;
1399 		lsn = lmWriteRecord(log, NULL, &lrd, NULL);
1400 		bp = log->bp;
1401 		bp->l_ceor = bp->l_eor;
1402 		lp = (struct logpage *) bp->l_ldata;
1403 		lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
1404 		lbmWrite(log, bp, lbmWRITE | lbmSYNC, 0);
1405 		if ((rc = lbmIOWait(bp, 0)))
1406 			goto errout30;
1407 
1408 		/*
1409 		 * update/write superblock
1410 		 */
1411 		logsuper->state = cpu_to_le32(LOGMOUNT);
1412 		log->serial = le32_to_cpu(logsuper->serial) + 1;
1413 		logsuper->serial = cpu_to_le32(log->serial);
1414 		lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1415 		if ((rc = lbmIOWait(bpsuper, lbmFREE)))
1416 			goto errout30;
1417 	}
1418 
1419 	/* initialize logsync parameters */
1420 	log->logsize = (log->size - 2) << L2LOGPSIZE;
1421 	log->lsn = lsn;
1422 	log->syncpt = lsn;
1423 	log->sync = log->syncpt;
1424 	log->nextsync = LOGSYNC_DELTA(log->logsize);
1425 
1426 	jfs_info("lmLogInit: lsn:0x%x syncpt:0x%x sync:0x%x",
1427 		 log->lsn, log->syncpt, log->sync);
1428 
1429 	/*
1430 	 * initialize for lazy/group commit
1431 	 */
1432 	log->clsn = lsn;
1433 
1434 	return 0;
1435 
1436 	/*
1437 	 *      unwind on error
1438 	 */
1439       errout30:		/* release log page */
1440 	log->wqueue = NULL;
1441 	bp->l_wqnext = NULL;
1442 	lbmFree(bp);
1443 
1444       errout20:		/* release log superblock */
1445 	lbmFree(bpsuper);
1446 
1447       errout10:		/* unwind lbmLogInit() */
1448 	lbmLogShutdown(log);
1449 
1450 	jfs_warn("lmLogInit: exit(%d)", rc);
1451 	return rc;
1452 }
1453 
1454 
1455 /*
1456  * NAME:	lmLogClose()
1457  *
1458  * FUNCTION:	remove file system <ipmnt> from active list of log <iplog>
1459  *		and close it on last close.
1460  *
1461  * PARAMETER:	sb	- superblock
1462  *
1463  * RETURN:	errors from subroutines
1464  *
1465  * serialization:
1466  */
1467 int lmLogClose(struct super_block *sb)
1468 {
1469 	struct jfs_sb_info *sbi = JFS_SBI(sb);
1470 	struct jfs_log *log = sbi->log;
1471 	struct block_device *bdev;
1472 	int rc = 0;
1473 
1474 	jfs_info("lmLogClose: log:0x%p", log);
1475 
1476 	down(&jfs_log_sem);
1477 	LOG_LOCK(log);
1478 	list_del(&sbi->log_list);
1479 	LOG_UNLOCK(log);
1480 	sbi->log = NULL;
1481 
1482 	/*
1483 	 * We need to make sure all of the "written" metapages
1484 	 * actually make it to disk
1485 	 */
1486 	sync_blockdev(sb->s_bdev);
1487 
1488 	if (test_bit(log_INLINELOG, &log->flag)) {
1489 		/*
1490 		 *      in-line log in host file system
1491 		 */
1492 		rc = lmLogShutdown(log);
1493 		kfree(log);
1494 		goto out;
1495 	}
1496 
1497 	if (!log->no_integrity)
1498 		lmLogFileSystem(log, sbi, 0);
1499 
1500 	if (!list_empty(&log->sb_list))
1501 		goto out;
1502 
1503 	/*
1504 	 * TODO: ensure that the dummy_log is in a state to allow
1505 	 * lbmLogShutdown to deallocate all the buffers and call
1506 	 * kfree against dummy_log.  For now, leave dummy_log & its
1507 	 * buffers in memory, and resuse if another no-integrity mount
1508 	 * is requested.
1509 	 */
1510 	if (log->no_integrity)
1511 		goto out;
1512 
1513 	/*
1514 	 *      external log as separate logical volume
1515 	 */
1516 	list_del(&log->journal_list);
1517 	bdev = log->bdev;
1518 	rc = lmLogShutdown(log);
1519 
1520 	bd_release(bdev);
1521 	blkdev_put(bdev);
1522 
1523 	kfree(log);
1524 
1525       out:
1526 	up(&jfs_log_sem);
1527 	jfs_info("lmLogClose: exit(%d)", rc);
1528 	return rc;
1529 }
1530 
1531 
1532 /*
1533  * NAME:	jfs_flush_journal()
1534  *
1535  * FUNCTION:	initiate write of any outstanding transactions to the journal
1536  *		and optionally wait until they are all written to disk
1537  *
1538  *		wait == 0  flush until latest txn is committed, don't wait
1539  *		wait == 1  flush until latest txn is committed, wait
1540  *		wait > 1   flush until all txn's are complete, wait
1541  */
1542 void jfs_flush_journal(struct jfs_log *log, int wait)
1543 {
1544 	int i;
1545 	struct tblock *target = NULL;
1546 	struct jfs_sb_info *sbi;
1547 
1548 	/* jfs_write_inode may call us during read-only mount */
1549 	if (!log)
1550 		return;
1551 
1552 	jfs_info("jfs_flush_journal: log:0x%p wait=%d", log, wait);
1553 
1554 	LOGGC_LOCK(log);
1555 
1556 	if (!list_empty(&log->cqueue)) {
1557 		/*
1558 		 * This ensures that we will keep writing to the journal as long
1559 		 * as there are unwritten commit records
1560 		 */
1561 		target = list_entry(log->cqueue.prev, struct tblock, cqueue);
1562 
1563 		if (test_bit(log_FLUSH, &log->flag)) {
1564 			/*
1565 			 * We're already flushing.
1566 			 * if flush_tblk is NULL, we are flushing everything,
1567 			 * so leave it that way.  Otherwise, update it to the
1568 			 * latest transaction
1569 			 */
1570 			if (log->flush_tblk)
1571 				log->flush_tblk = target;
1572 		} else {
1573 			/* Only flush until latest transaction is committed */
1574 			log->flush_tblk = target;
1575 			set_bit(log_FLUSH, &log->flag);
1576 
1577 			/*
1578 			 * Initiate I/O on outstanding transactions
1579 			 */
1580 			if (!(log->cflag & logGC_PAGEOUT)) {
1581 				log->cflag |= logGC_PAGEOUT;
1582 				lmGCwrite(log, 0);
1583 			}
1584 		}
1585 	}
1586 	if ((wait > 1) || test_bit(log_SYNCBARRIER, &log->flag)) {
1587 		/* Flush until all activity complete */
1588 		set_bit(log_FLUSH, &log->flag);
1589 		log->flush_tblk = NULL;
1590 	}
1591 
1592 	if (wait && target && !(target->flag & tblkGC_COMMITTED)) {
1593 		DECLARE_WAITQUEUE(__wait, current);
1594 
1595 		add_wait_queue(&target->gcwait, &__wait);
1596 		set_current_state(TASK_UNINTERRUPTIBLE);
1597 		LOGGC_UNLOCK(log);
1598 		schedule();
1599 		current->state = TASK_RUNNING;
1600 		LOGGC_LOCK(log);
1601 		remove_wait_queue(&target->gcwait, &__wait);
1602 	}
1603 	LOGGC_UNLOCK(log);
1604 
1605 	if (wait < 2)
1606 		return;
1607 
1608 	list_for_each_entry(sbi, &log->sb_list, log_list) {
1609 		filemap_fdatawrite(sbi->ipbmap->i_mapping);
1610 		filemap_fdatawrite(sbi->ipimap->i_mapping);
1611 		filemap_fdatawrite(sbi->direct_inode->i_mapping);
1612 	}
1613 
1614 	/*
1615 	 * If there was recent activity, we may need to wait
1616 	 * for the lazycommit thread to catch up
1617 	 */
1618 	if ((!list_empty(&log->cqueue)) || !list_empty(&log->synclist)) {
1619 		for (i = 0; i < 200; i++) {	/* Too much? */
1620 			msleep(250);
1621 			if (list_empty(&log->cqueue) &&
1622 			    list_empty(&log->synclist))
1623 				break;
1624 		}
1625 	}
1626 	assert(list_empty(&log->cqueue));
1627 	if (!list_empty(&log->synclist)) {
1628 		struct logsyncblk *lp;
1629 
1630 		list_for_each_entry(lp, &log->synclist, synclist) {
1631 			if (lp->xflag & COMMIT_PAGE) {
1632 				struct metapage *mp = (struct metapage *)lp;
1633 				dump_mem("orphan metapage", lp,
1634 					 sizeof(struct metapage));
1635 				dump_mem("page", mp->page, sizeof(struct page));
1636 			}
1637 			else
1638 				dump_mem("orphan tblock", lp,
1639 					 sizeof(struct tblock));
1640 		}
1641 //		current->state = TASK_INTERRUPTIBLE;
1642 //		schedule();
1643 	}
1644 	//assert(list_empty(&log->synclist));
1645 	clear_bit(log_FLUSH, &log->flag);
1646 }
1647 
1648 /*
1649  * NAME:	lmLogShutdown()
1650  *
1651  * FUNCTION:	log shutdown at last LogClose().
1652  *
1653  *		write log syncpt record.
1654  *		update super block to set redone flag to 0.
1655  *
1656  * PARAMETER:	log	- log inode
1657  *
1658  * RETURN:	0	- success
1659  *
1660  * serialization: single last close thread
1661  */
1662 int lmLogShutdown(struct jfs_log * log)
1663 {
1664 	int rc;
1665 	struct lrd lrd;
1666 	int lsn;
1667 	struct logsuper *logsuper;
1668 	struct lbuf *bpsuper;
1669 	struct lbuf *bp;
1670 	struct logpage *lp;
1671 
1672 	jfs_info("lmLogShutdown: log:0x%p", log);
1673 
1674 	jfs_flush_journal(log, 2);
1675 
1676 	/*
1677 	 * write the last SYNCPT record with syncpoint = 0
1678 	 * (i.e., log redo up to HERE !)
1679 	 */
1680 	lrd.logtid = 0;
1681 	lrd.backchain = 0;
1682 	lrd.type = cpu_to_le16(LOG_SYNCPT);
1683 	lrd.length = 0;
1684 	lrd.log.syncpt.sync = 0;
1685 
1686 	lsn = lmWriteRecord(log, NULL, &lrd, NULL);
1687 	bp = log->bp;
1688 	lp = (struct logpage *) bp->l_ldata;
1689 	lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
1690 	lbmWrite(log, log->bp, lbmWRITE | lbmRELEASE | lbmSYNC, 0);
1691 	lbmIOWait(log->bp, lbmFREE);
1692 	log->bp = NULL;
1693 
1694 	/*
1695 	 * synchronous update log superblock
1696 	 * mark log state as shutdown cleanly
1697 	 * (i.e., Log does not need to be replayed).
1698 	 */
1699 	if ((rc = lbmRead(log, 1, &bpsuper)))
1700 		goto out;
1701 
1702 	logsuper = (struct logsuper *) bpsuper->l_ldata;
1703 	logsuper->state = cpu_to_le32(LOGREDONE);
1704 	logsuper->end = cpu_to_le32(lsn);
1705 	lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1706 	rc = lbmIOWait(bpsuper, lbmFREE);
1707 
1708 	jfs_info("lmLogShutdown: lsn:0x%x page:%d eor:%d",
1709 		 lsn, log->page, log->eor);
1710 
1711       out:
1712 	/*
1713 	 * shutdown per log i/o
1714 	 */
1715 	lbmLogShutdown(log);
1716 
1717 	if (rc) {
1718 		jfs_warn("lmLogShutdown: exit(%d)", rc);
1719 	}
1720 	return rc;
1721 }
1722 
1723 
1724 /*
1725  * NAME:	lmLogFileSystem()
1726  *
1727  * FUNCTION:	insert (<activate> = true)/remove (<activate> = false)
1728  *	file system into/from log active file system list.
1729  *
1730  * PARAMETE:	log	- pointer to logs inode.
1731  *		fsdev	- kdev_t of filesystem.
1732  *		serial  - pointer to returned log serial number
1733  *		activate - insert/remove device from active list.
1734  *
1735  * RETURN:	0	- success
1736  *		errors returned by vms_iowait().
1737  */
1738 static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
1739 			   int activate)
1740 {
1741 	int rc = 0;
1742 	int i;
1743 	struct logsuper *logsuper;
1744 	struct lbuf *bpsuper;
1745 	char *uuid = sbi->uuid;
1746 
1747 	/*
1748 	 * insert/remove file system device to log active file system list.
1749 	 */
1750 	if ((rc = lbmRead(log, 1, &bpsuper)))
1751 		return rc;
1752 
1753 	logsuper = (struct logsuper *) bpsuper->l_ldata;
1754 	if (activate) {
1755 		for (i = 0; i < MAX_ACTIVE; i++)
1756 			if (!memcmp(logsuper->active[i].uuid, NULL_UUID, 16)) {
1757 				memcpy(logsuper->active[i].uuid, uuid, 16);
1758 				sbi->aggregate = i;
1759 				break;
1760 			}
1761 		if (i == MAX_ACTIVE) {
1762 			jfs_warn("Too many file systems sharing journal!");
1763 			lbmFree(bpsuper);
1764 			return -EMFILE;	/* Is there a better rc? */
1765 		}
1766 	} else {
1767 		for (i = 0; i < MAX_ACTIVE; i++)
1768 			if (!memcmp(logsuper->active[i].uuid, uuid, 16)) {
1769 				memcpy(logsuper->active[i].uuid, NULL_UUID, 16);
1770 				break;
1771 			}
1772 		if (i == MAX_ACTIVE) {
1773 			jfs_warn("Somebody stomped on the journal!");
1774 			lbmFree(bpsuper);
1775 			return -EIO;
1776 		}
1777 
1778 	}
1779 
1780 	/*
1781 	 * synchronous write log superblock:
1782 	 *
1783 	 * write sidestream bypassing write queue:
1784 	 * at file system mount, log super block is updated for
1785 	 * activation of the file system before any log record
1786 	 * (MOUNT record) of the file system, and at file system
1787 	 * unmount, all meta data for the file system has been
1788 	 * flushed before log super block is updated for deactivation
1789 	 * of the file system.
1790 	 */
1791 	lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1792 	rc = lbmIOWait(bpsuper, lbmFREE);
1793 
1794 	return rc;
1795 }
1796 
1797 /*
1798  *		log buffer manager (lbm)
1799  *		------------------------
1800  *
1801  * special purpose buffer manager supporting log i/o requirements.
1802  *
1803  * per log write queue:
1804  * log pageout occurs in serial order by fifo write queue and
1805  * restricting to a single i/o in pregress at any one time.
1806  * a circular singly-linked list
1807  * (log->wrqueue points to the tail, and buffers are linked via
1808  * bp->wrqueue field), and
1809  * maintains log page in pageout ot waiting for pageout in serial pageout.
1810  */
1811 
1812 /*
1813  *	lbmLogInit()
1814  *
1815  * initialize per log I/O setup at lmLogInit()
1816  */
1817 static int lbmLogInit(struct jfs_log * log)
1818 {				/* log inode */
1819 	int i;
1820 	struct lbuf *lbuf;
1821 
1822 	jfs_info("lbmLogInit: log:0x%p", log);
1823 
1824 	/* initialize current buffer cursor */
1825 	log->bp = NULL;
1826 
1827 	/* initialize log device write queue */
1828 	log->wqueue = NULL;
1829 
1830 	/*
1831 	 * Each log has its own buffer pages allocated to it.  These are
1832 	 * not managed by the page cache.  This ensures that a transaction
1833 	 * writing to the log does not block trying to allocate a page from
1834 	 * the page cache (for the log).  This would be bad, since page
1835 	 * allocation waits on the kswapd thread that may be committing inodes
1836 	 * which would cause log activity.  Was that clear?  I'm trying to
1837 	 * avoid deadlock here.
1838 	 */
1839 	init_waitqueue_head(&log->free_wait);
1840 
1841 	log->lbuf_free = NULL;
1842 
1843 	for (i = 0; i < LOGPAGES;) {
1844 		char *buffer;
1845 		uint offset;
1846 		struct page *page;
1847 
1848 		buffer = (char *) get_zeroed_page(GFP_KERNEL);
1849 		if (buffer == NULL)
1850 			goto error;
1851 		page = virt_to_page(buffer);
1852 		for (offset = 0; offset < PAGE_SIZE; offset += LOGPSIZE) {
1853 			lbuf = kmalloc(sizeof(struct lbuf), GFP_KERNEL);
1854 			if (lbuf == NULL) {
1855 				if (offset == 0)
1856 					free_page((unsigned long) buffer);
1857 				goto error;
1858 			}
1859 			if (offset) /* we already have one reference */
1860 				get_page(page);
1861 			lbuf->l_offset = offset;
1862 			lbuf->l_ldata = buffer + offset;
1863 			lbuf->l_page = page;
1864 			lbuf->l_log = log;
1865 			init_waitqueue_head(&lbuf->l_ioevent);
1866 
1867 			lbuf->l_freelist = log->lbuf_free;
1868 			log->lbuf_free = lbuf;
1869 			i++;
1870 		}
1871 	}
1872 
1873 	return (0);
1874 
1875       error:
1876 	lbmLogShutdown(log);
1877 	return -ENOMEM;
1878 }
1879 
1880 
1881 /*
1882  *	lbmLogShutdown()
1883  *
1884  * finalize per log I/O setup at lmLogShutdown()
1885  */
1886 static void lbmLogShutdown(struct jfs_log * log)
1887 {
1888 	struct lbuf *lbuf;
1889 
1890 	jfs_info("lbmLogShutdown: log:0x%p", log);
1891 
1892 	lbuf = log->lbuf_free;
1893 	while (lbuf) {
1894 		struct lbuf *next = lbuf->l_freelist;
1895 		__free_page(lbuf->l_page);
1896 		kfree(lbuf);
1897 		lbuf = next;
1898 	}
1899 }
1900 
1901 
1902 /*
1903  *	lbmAllocate()
1904  *
1905  * allocate an empty log buffer
1906  */
1907 static struct lbuf *lbmAllocate(struct jfs_log * log, int pn)
1908 {
1909 	struct lbuf *bp;
1910 	unsigned long flags;
1911 
1912 	/*
1913 	 * recycle from log buffer freelist if any
1914 	 */
1915 	LCACHE_LOCK(flags);
1916 	LCACHE_SLEEP_COND(log->free_wait, (bp = log->lbuf_free), flags);
1917 	log->lbuf_free = bp->l_freelist;
1918 	LCACHE_UNLOCK(flags);
1919 
1920 	bp->l_flag = 0;
1921 
1922 	bp->l_wqnext = NULL;
1923 	bp->l_freelist = NULL;
1924 
1925 	bp->l_pn = pn;
1926 	bp->l_blkno = log->base + (pn << (L2LOGPSIZE - log->l2bsize));
1927 	bp->l_ceor = 0;
1928 
1929 	return bp;
1930 }
1931 
1932 
1933 /*
1934  *	lbmFree()
1935  *
1936  * release a log buffer to freelist
1937  */
1938 static void lbmFree(struct lbuf * bp)
1939 {
1940 	unsigned long flags;
1941 
1942 	LCACHE_LOCK(flags);
1943 
1944 	lbmfree(bp);
1945 
1946 	LCACHE_UNLOCK(flags);
1947 }
1948 
1949 static void lbmfree(struct lbuf * bp)
1950 {
1951 	struct jfs_log *log = bp->l_log;
1952 
1953 	assert(bp->l_wqnext == NULL);
1954 
1955 	/*
1956 	 * return the buffer to head of freelist
1957 	 */
1958 	bp->l_freelist = log->lbuf_free;
1959 	log->lbuf_free = bp;
1960 
1961 	wake_up(&log->free_wait);
1962 	return;
1963 }
1964 
1965 
1966 /*
1967  * NAME:	lbmRedrive
1968  *
1969  * FUNCTION:	add a log buffer to the the log redrive list
1970  *
1971  * PARAMETER:
1972  *     bp	- log buffer
1973  *
1974  * NOTES:
1975  *	Takes log_redrive_lock.
1976  */
1977 static inline void lbmRedrive(struct lbuf *bp)
1978 {
1979 	unsigned long flags;
1980 
1981 	spin_lock_irqsave(&log_redrive_lock, flags);
1982 	bp->l_redrive_next = log_redrive_list;
1983 	log_redrive_list = bp;
1984 	spin_unlock_irqrestore(&log_redrive_lock, flags);
1985 
1986 	wake_up(&jfs_IO_thread_wait);
1987 }
1988 
1989 
1990 /*
1991  *	lbmRead()
1992  */
1993 static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
1994 {
1995 	struct bio *bio;
1996 	struct lbuf *bp;
1997 
1998 	/*
1999 	 * allocate a log buffer
2000 	 */
2001 	*bpp = bp = lbmAllocate(log, pn);
2002 	jfs_info("lbmRead: bp:0x%p pn:0x%x", bp, pn);
2003 
2004 	bp->l_flag |= lbmREAD;
2005 
2006 	bio = bio_alloc(GFP_NOFS, 1);
2007 
2008 	bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
2009 	bio->bi_bdev = log->bdev;
2010 	bio->bi_io_vec[0].bv_page = bp->l_page;
2011 	bio->bi_io_vec[0].bv_len = LOGPSIZE;
2012 	bio->bi_io_vec[0].bv_offset = bp->l_offset;
2013 
2014 	bio->bi_vcnt = 1;
2015 	bio->bi_idx = 0;
2016 	bio->bi_size = LOGPSIZE;
2017 
2018 	bio->bi_end_io = lbmIODone;
2019 	bio->bi_private = bp;
2020 	submit_bio(READ_SYNC, bio);
2021 
2022 	wait_event(bp->l_ioevent, (bp->l_flag != lbmREAD));
2023 
2024 	return 0;
2025 }
2026 
2027 
2028 /*
2029  *	lbmWrite()
2030  *
2031  * buffer at head of pageout queue stays after completion of
2032  * partial-page pageout and redriven by explicit initiation of
2033  * pageout by caller until full-page pageout is completed and
2034  * released.
2035  *
2036  * device driver i/o done redrives pageout of new buffer at
2037  * head of pageout queue when current buffer at head of pageout
2038  * queue is released at the completion of its full-page pageout.
2039  *
2040  * LOGGC_LOCK() serializes lbmWrite() by lmNextPage() and lmGroupCommit().
2041  * LCACHE_LOCK() serializes xflag between lbmWrite() and lbmIODone()
2042  */
2043 static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag,
2044 		     int cant_block)
2045 {
2046 	struct lbuf *tail;
2047 	unsigned long flags;
2048 
2049 	jfs_info("lbmWrite: bp:0x%p flag:0x%x pn:0x%x", bp, flag, bp->l_pn);
2050 
2051 	/* map the logical block address to physical block address */
2052 	bp->l_blkno =
2053 	    log->base + (bp->l_pn << (L2LOGPSIZE - log->l2bsize));
2054 
2055 	LCACHE_LOCK(flags);		/* disable+lock */
2056 
2057 	/*
2058 	 * initialize buffer for device driver
2059 	 */
2060 	bp->l_flag = flag;
2061 
2062 	/*
2063 	 *      insert bp at tail of write queue associated with log
2064 	 *
2065 	 * (request is either for bp already/currently at head of queue
2066 	 * or new bp to be inserted at tail)
2067 	 */
2068 	tail = log->wqueue;
2069 
2070 	/* is buffer not already on write queue ? */
2071 	if (bp->l_wqnext == NULL) {
2072 		/* insert at tail of wqueue */
2073 		if (tail == NULL) {
2074 			log->wqueue = bp;
2075 			bp->l_wqnext = bp;
2076 		} else {
2077 			log->wqueue = bp;
2078 			bp->l_wqnext = tail->l_wqnext;
2079 			tail->l_wqnext = bp;
2080 		}
2081 
2082 		tail = bp;
2083 	}
2084 
2085 	/* is buffer at head of wqueue and for write ? */
2086 	if ((bp != tail->l_wqnext) || !(flag & lbmWRITE)) {
2087 		LCACHE_UNLOCK(flags);	/* unlock+enable */
2088 		return;
2089 	}
2090 
2091 	LCACHE_UNLOCK(flags);	/* unlock+enable */
2092 
2093 	if (cant_block)
2094 		lbmRedrive(bp);
2095 	else if (flag & lbmSYNC)
2096 		lbmStartIO(bp);
2097 	else {
2098 		LOGGC_UNLOCK(log);
2099 		lbmStartIO(bp);
2100 		LOGGC_LOCK(log);
2101 	}
2102 }
2103 
2104 
2105 /*
2106  *	lbmDirectWrite()
2107  *
2108  * initiate pageout bypassing write queue for sidestream
2109  * (e.g., log superblock) write;
2110  */
2111 static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag)
2112 {
2113 	jfs_info("lbmDirectWrite: bp:0x%p flag:0x%x pn:0x%x",
2114 		 bp, flag, bp->l_pn);
2115 
2116 	/*
2117 	 * initialize buffer for device driver
2118 	 */
2119 	bp->l_flag = flag | lbmDIRECT;
2120 
2121 	/* map the logical block address to physical block address */
2122 	bp->l_blkno =
2123 	    log->base + (bp->l_pn << (L2LOGPSIZE - log->l2bsize));
2124 
2125 	/*
2126 	 *      initiate pageout of the page
2127 	 */
2128 	lbmStartIO(bp);
2129 }
2130 
2131 
2132 /*
2133  * NAME:	lbmStartIO()
2134  *
2135  * FUNCTION:	Interface to DD strategy routine
2136  *
2137  * RETURN:      none
2138  *
2139  * serialization: LCACHE_LOCK() is NOT held during log i/o;
2140  */
2141 static void lbmStartIO(struct lbuf * bp)
2142 {
2143 	struct bio *bio;
2144 	struct jfs_log *log = bp->l_log;
2145 
2146 	jfs_info("lbmStartIO\n");
2147 
2148 	bio = bio_alloc(GFP_NOFS, 1);
2149 	bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
2150 	bio->bi_bdev = log->bdev;
2151 	bio->bi_io_vec[0].bv_page = bp->l_page;
2152 	bio->bi_io_vec[0].bv_len = LOGPSIZE;
2153 	bio->bi_io_vec[0].bv_offset = bp->l_offset;
2154 
2155 	bio->bi_vcnt = 1;
2156 	bio->bi_idx = 0;
2157 	bio->bi_size = LOGPSIZE;
2158 
2159 	bio->bi_end_io = lbmIODone;
2160 	bio->bi_private = bp;
2161 
2162 	/* check if journaling to disk has been disabled */
2163 	if (log->no_integrity) {
2164 		bio->bi_size = 0;
2165 		lbmIODone(bio, 0, 0);
2166 	} else {
2167 		submit_bio(WRITE_SYNC, bio);
2168 		INCREMENT(lmStat.submitted);
2169 	}
2170 }
2171 
2172 
2173 /*
2174  *	lbmIOWait()
2175  */
2176 static int lbmIOWait(struct lbuf * bp, int flag)
2177 {
2178 	unsigned long flags;
2179 	int rc = 0;
2180 
2181 	jfs_info("lbmIOWait1: bp:0x%p flag:0x%x:0x%x", bp, bp->l_flag, flag);
2182 
2183 	LCACHE_LOCK(flags);		/* disable+lock */
2184 
2185 	LCACHE_SLEEP_COND(bp->l_ioevent, (bp->l_flag & lbmDONE), flags);
2186 
2187 	rc = (bp->l_flag & lbmERROR) ? -EIO : 0;
2188 
2189 	if (flag & lbmFREE)
2190 		lbmfree(bp);
2191 
2192 	LCACHE_UNLOCK(flags);	/* unlock+enable */
2193 
2194 	jfs_info("lbmIOWait2: bp:0x%p flag:0x%x:0x%x", bp, bp->l_flag, flag);
2195 	return rc;
2196 }
2197 
2198 /*
2199  *	lbmIODone()
2200  *
2201  * executed at INTIODONE level
2202  */
2203 static int lbmIODone(struct bio *bio, unsigned int bytes_done, int error)
2204 {
2205 	struct lbuf *bp = bio->bi_private;
2206 	struct lbuf *nextbp, *tail;
2207 	struct jfs_log *log;
2208 	unsigned long flags;
2209 
2210 	if (bio->bi_size)
2211 		return 1;
2212 
2213 	/*
2214 	 * get back jfs buffer bound to the i/o buffer
2215 	 */
2216 	jfs_info("lbmIODone: bp:0x%p flag:0x%x", bp, bp->l_flag);
2217 
2218 	LCACHE_LOCK(flags);		/* disable+lock */
2219 
2220 	bp->l_flag |= lbmDONE;
2221 
2222 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
2223 		bp->l_flag |= lbmERROR;
2224 
2225 		jfs_err("lbmIODone: I/O error in JFS log");
2226 	}
2227 
2228 	bio_put(bio);
2229 
2230 	/*
2231 	 *      pagein completion
2232 	 */
2233 	if (bp->l_flag & lbmREAD) {
2234 		bp->l_flag &= ~lbmREAD;
2235 
2236 		LCACHE_UNLOCK(flags);	/* unlock+enable */
2237 
2238 		/* wakeup I/O initiator */
2239 		LCACHE_WAKEUP(&bp->l_ioevent);
2240 
2241 		return 0;
2242 	}
2243 
2244 	/*
2245 	 *      pageout completion
2246 	 *
2247 	 * the bp at the head of write queue has completed pageout.
2248 	 *
2249 	 * if single-commit/full-page pageout, remove the current buffer
2250 	 * from head of pageout queue, and redrive pageout with
2251 	 * the new buffer at head of pageout queue;
2252 	 * otherwise, the partial-page pageout buffer stays at
2253 	 * the head of pageout queue to be redriven for pageout
2254 	 * by lmGroupCommit() until full-page pageout is completed.
2255 	 */
2256 	bp->l_flag &= ~lbmWRITE;
2257 	INCREMENT(lmStat.pagedone);
2258 
2259 	/* update committed lsn */
2260 	log = bp->l_log;
2261 	log->clsn = (bp->l_pn << L2LOGPSIZE) + bp->l_ceor;
2262 
2263 	if (bp->l_flag & lbmDIRECT) {
2264 		LCACHE_WAKEUP(&bp->l_ioevent);
2265 		LCACHE_UNLOCK(flags);
2266 		return 0;
2267 	}
2268 
2269 	tail = log->wqueue;
2270 
2271 	/* single element queue */
2272 	if (bp == tail) {
2273 		/* remove head buffer of full-page pageout
2274 		 * from log device write queue
2275 		 */
2276 		if (bp->l_flag & lbmRELEASE) {
2277 			log->wqueue = NULL;
2278 			bp->l_wqnext = NULL;
2279 		}
2280 	}
2281 	/* multi element queue */
2282 	else {
2283 		/* remove head buffer of full-page pageout
2284 		 * from log device write queue
2285 		 */
2286 		if (bp->l_flag & lbmRELEASE) {
2287 			nextbp = tail->l_wqnext = bp->l_wqnext;
2288 			bp->l_wqnext = NULL;
2289 
2290 			/*
2291 			 * redrive pageout of next page at head of write queue:
2292 			 * redrive next page without any bound tblk
2293 			 * (i.e., page w/o any COMMIT records), or
2294 			 * first page of new group commit which has been
2295 			 * queued after current page (subsequent pageout
2296 			 * is performed synchronously, except page without
2297 			 * any COMMITs) by lmGroupCommit() as indicated
2298 			 * by lbmWRITE flag;
2299 			 */
2300 			if (nextbp->l_flag & lbmWRITE) {
2301 				/*
2302 				 * We can't do the I/O at interrupt time.
2303 				 * The jfsIO thread can do it
2304 				 */
2305 				lbmRedrive(nextbp);
2306 			}
2307 		}
2308 	}
2309 
2310 	/*
2311 	 *      synchronous pageout:
2312 	 *
2313 	 * buffer has not necessarily been removed from write queue
2314 	 * (e.g., synchronous write of partial-page with COMMIT):
2315 	 * leave buffer for i/o initiator to dispose
2316 	 */
2317 	if (bp->l_flag & lbmSYNC) {
2318 		LCACHE_UNLOCK(flags);	/* unlock+enable */
2319 
2320 		/* wakeup I/O initiator */
2321 		LCACHE_WAKEUP(&bp->l_ioevent);
2322 	}
2323 
2324 	/*
2325 	 *      Group Commit pageout:
2326 	 */
2327 	else if (bp->l_flag & lbmGC) {
2328 		LCACHE_UNLOCK(flags);
2329 		lmPostGC(bp);
2330 	}
2331 
2332 	/*
2333 	 *      asynchronous pageout:
2334 	 *
2335 	 * buffer must have been removed from write queue:
2336 	 * insert buffer at head of freelist where it can be recycled
2337 	 */
2338 	else {
2339 		assert(bp->l_flag & lbmRELEASE);
2340 		assert(bp->l_flag & lbmFREE);
2341 		lbmfree(bp);
2342 
2343 		LCACHE_UNLOCK(flags);	/* unlock+enable */
2344 	}
2345 
2346 	return 0;
2347 }
2348 
2349 int jfsIOWait(void *arg)
2350 {
2351 	struct lbuf *bp;
2352 
2353 	daemonize("jfsIO");
2354 
2355 	complete(&jfsIOwait);
2356 
2357 	do {
2358 		DECLARE_WAITQUEUE(wq, current);
2359 
2360 		spin_lock_irq(&log_redrive_lock);
2361 		while ((bp = log_redrive_list) != 0) {
2362 			log_redrive_list = bp->l_redrive_next;
2363 			bp->l_redrive_next = NULL;
2364 			spin_unlock_irq(&log_redrive_lock);
2365 			lbmStartIO(bp);
2366 			spin_lock_irq(&log_redrive_lock);
2367 		}
2368 		if (current->flags & PF_FREEZE) {
2369 			spin_unlock_irq(&log_redrive_lock);
2370 			refrigerator(PF_FREEZE);
2371 		} else {
2372 			add_wait_queue(&jfs_IO_thread_wait, &wq);
2373 			set_current_state(TASK_INTERRUPTIBLE);
2374 			spin_unlock_irq(&log_redrive_lock);
2375 			schedule();
2376 			current->state = TASK_RUNNING;
2377 			remove_wait_queue(&jfs_IO_thread_wait, &wq);
2378 		}
2379 	} while (!jfs_stop_threads);
2380 
2381 	jfs_info("jfsIOWait being killed!");
2382 	complete_and_exit(&jfsIOwait, 0);
2383 }
2384 
2385 /*
2386  * NAME:	lmLogFormat()/jfs_logform()
2387  *
2388  * FUNCTION:	format file system log
2389  *
2390  * PARAMETERS:
2391  *      log	- volume log
2392  *	logAddress - start address of log space in FS block
2393  *	logSize	- length of log space in FS block;
2394  *
2395  * RETURN:	0	- success
2396  *		-EIO	- i/o error
2397  *
2398  * XXX: We're synchronously writing one page at a time.  This needs to
2399  *	be improved by writing multiple pages at once.
2400  */
2401 int lmLogFormat(struct jfs_log *log, s64 logAddress, int logSize)
2402 {
2403 	int rc = -EIO;
2404 	struct jfs_sb_info *sbi;
2405 	struct logsuper *logsuper;
2406 	struct logpage *lp;
2407 	int lspn;		/* log sequence page number */
2408 	struct lrd *lrd_ptr;
2409 	int npages = 0;
2410 	struct lbuf *bp;
2411 
2412 	jfs_info("lmLogFormat: logAddress:%Ld logSize:%d",
2413 		 (long long)logAddress, logSize);
2414 
2415 	sbi = list_entry(log->sb_list.next, struct jfs_sb_info, log_list);
2416 
2417 	/* allocate a log buffer */
2418 	bp = lbmAllocate(log, 1);
2419 
2420 	npages = logSize >> sbi->l2nbperpage;
2421 
2422 	/*
2423 	 *      log space:
2424 	 *
2425 	 * page 0 - reserved;
2426 	 * page 1 - log superblock;
2427 	 * page 2 - log data page: A SYNC log record is written
2428 	 *          into this page at logform time;
2429 	 * pages 3-N - log data page: set to empty log data pages;
2430 	 */
2431 	/*
2432 	 *      init log superblock: log page 1
2433 	 */
2434 	logsuper = (struct logsuper *) bp->l_ldata;
2435 
2436 	logsuper->magic = cpu_to_le32(LOGMAGIC);
2437 	logsuper->version = cpu_to_le32(LOGVERSION);
2438 	logsuper->state = cpu_to_le32(LOGREDONE);
2439 	logsuper->flag = cpu_to_le32(sbi->mntflag);	/* ? */
2440 	logsuper->size = cpu_to_le32(npages);
2441 	logsuper->bsize = cpu_to_le32(sbi->bsize);
2442 	logsuper->l2bsize = cpu_to_le32(sbi->l2bsize);
2443 	logsuper->end = cpu_to_le32(2 * LOGPSIZE + LOGPHDRSIZE + LOGRDSIZE);
2444 
2445 	bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2446 	bp->l_blkno = logAddress + sbi->nbperpage;
2447 	lbmStartIO(bp);
2448 	if ((rc = lbmIOWait(bp, 0)))
2449 		goto exit;
2450 
2451 	/*
2452 	 *      init pages 2 to npages-1 as log data pages:
2453 	 *
2454 	 * log page sequence number (lpsn) initialization:
2455 	 *
2456 	 * pn:   0     1     2     3                 n-1
2457 	 *       +-----+-----+=====+=====+===.....===+=====+
2458 	 * lspn:             N-1   0     1           N-2
2459 	 *                   <--- N page circular file ---->
2460 	 *
2461 	 * the N (= npages-2) data pages of the log is maintained as
2462 	 * a circular file for the log records;
2463 	 * lpsn grows by 1 monotonically as each log page is written
2464 	 * to the circular file of the log;
2465 	 * and setLogpage() will not reset the page number even if
2466 	 * the eor is equal to LOGPHDRSIZE. In order for binary search
2467 	 * still work in find log end process, we have to simulate the
2468 	 * log wrap situation at the log format time.
2469 	 * The 1st log page written will have the highest lpsn. Then
2470 	 * the succeeding log pages will have ascending order of
2471 	 * the lspn starting from 0, ... (N-2)
2472 	 */
2473 	lp = (struct logpage *) bp->l_ldata;
2474 	/*
2475 	 * initialize 1st log page to be written: lpsn = N - 1,
2476 	 * write a SYNCPT log record is written to this page
2477 	 */
2478 	lp->h.page = lp->t.page = cpu_to_le32(npages - 3);
2479 	lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE + LOGRDSIZE);
2480 
2481 	lrd_ptr = (struct lrd *) &lp->data;
2482 	lrd_ptr->logtid = 0;
2483 	lrd_ptr->backchain = 0;
2484 	lrd_ptr->type = cpu_to_le16(LOG_SYNCPT);
2485 	lrd_ptr->length = 0;
2486 	lrd_ptr->log.syncpt.sync = 0;
2487 
2488 	bp->l_blkno += sbi->nbperpage;
2489 	bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2490 	lbmStartIO(bp);
2491 	if ((rc = lbmIOWait(bp, 0)))
2492 		goto exit;
2493 
2494 	/*
2495 	 *      initialize succeeding log pages: lpsn = 0, 1, ..., (N-2)
2496 	 */
2497 	for (lspn = 0; lspn < npages - 3; lspn++) {
2498 		lp->h.page = lp->t.page = cpu_to_le32(lspn);
2499 		lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
2500 
2501 		bp->l_blkno += sbi->nbperpage;
2502 		bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2503 		lbmStartIO(bp);
2504 		if ((rc = lbmIOWait(bp, 0)))
2505 			goto exit;
2506 	}
2507 
2508 	rc = 0;
2509 exit:
2510 	/*
2511 	 *      finalize log
2512 	 */
2513 	/* release the buffer */
2514 	lbmFree(bp);
2515 
2516 	return rc;
2517 }
2518 
2519 #ifdef CONFIG_JFS_STATISTICS
2520 int jfs_lmstats_read(char *buffer, char **start, off_t offset, int length,
2521 		      int *eof, void *data)
2522 {
2523 	int len = 0;
2524 	off_t begin;
2525 
2526 	len += sprintf(buffer,
2527 		       "JFS Logmgr stats\n"
2528 		       "================\n"
2529 		       "commits = %d\n"
2530 		       "writes submitted = %d\n"
2531 		       "writes completed = %d\n"
2532 		       "full pages submitted = %d\n"
2533 		       "partial pages submitted = %d\n",
2534 		       lmStat.commit,
2535 		       lmStat.submitted,
2536 		       lmStat.pagedone,
2537 		       lmStat.full_page,
2538 		       lmStat.partial_page);
2539 
2540 	begin = offset;
2541 	*start = buffer + begin;
2542 	len -= begin;
2543 
2544 	if (len > length)
2545 		len = length;
2546 	else
2547 		*eof = 1;
2548 
2549 	if (len < 0)
2550 		len = 0;
2551 
2552 	return len;
2553 }
2554 #endif /* CONFIG_JFS_STATISTICS */
2555