xref: /openbmc/linux/fs/jfs/jfs_logmgr.c (revision 367b8112)
1 /*
2  *   Copyright (C) International Business Machines Corp., 2000-2004
3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 /*
21  *	jfs_logmgr.c: log manager
22  *
23  * for related information, see transaction manager (jfs_txnmgr.c), and
24  * recovery manager (jfs_logredo.c).
25  *
26  * note: for detail, RTFS.
27  *
28  *	log buffer manager:
29  * special purpose buffer manager supporting log i/o requirements.
30  * per log serial pageout of logpage
31  * queuing i/o requests and redrive i/o at iodone
32  * maintain current logpage buffer
33  * no caching since append only
34  * appropriate jfs buffer cache buffers as needed
35  *
36  *	group commit:
37  * transactions which wrote COMMIT records in the same in-memory
38  * log page during the pageout of previous/current log page(s) are
39  * committed together by the pageout of the page.
40  *
41  *	TBD lazy commit:
42  * transactions are committed asynchronously when the log page
43  * containing it COMMIT is paged out when it becomes full;
44  *
45  *	serialization:
46  * . a per log lock serialize log write.
47  * . a per log lock serialize group commit.
48  * . a per log lock serialize log open/close;
49  *
50  *	TBD log integrity:
51  * careful-write (ping-pong) of last logpage to recover from crash
52  * in overwrite.
53  * detection of split (out-of-order) write of physical sectors
54  * of last logpage via timestamp at end of each sector
55  * with its mirror data array at trailer).
56  *
57  *	alternatives:
58  * lsn - 64-bit monotonically increasing integer vs
59  * 32-bit lspn and page eor.
60  */
61 
62 #include <linux/fs.h>
63 #include <linux/blkdev.h>
64 #include <linux/interrupt.h>
65 #include <linux/completion.h>
66 #include <linux/kthread.h>
67 #include <linux/buffer_head.h>		/* for sync_blockdev() */
68 #include <linux/bio.h>
69 #include <linux/freezer.h>
70 #include <linux/delay.h>
71 #include <linux/mutex.h>
72 #include <linux/seq_file.h>
73 #include "jfs_incore.h"
74 #include "jfs_filsys.h"
75 #include "jfs_metapage.h"
76 #include "jfs_superblock.h"
77 #include "jfs_txnmgr.h"
78 #include "jfs_debug.h"
79 
80 
81 /*
82  * lbuf's ready to be redriven.  Protected by log_redrive_lock (jfsIO thread)
83  */
84 static struct lbuf *log_redrive_list;
85 static DEFINE_SPINLOCK(log_redrive_lock);
86 
87 
88 /*
89  *	log read/write serialization (per log)
90  */
91 #define LOG_LOCK_INIT(log)	mutex_init(&(log)->loglock)
92 #define LOG_LOCK(log)		mutex_lock(&((log)->loglock))
93 #define LOG_UNLOCK(log)		mutex_unlock(&((log)->loglock))
94 
95 
96 /*
97  *	log group commit serialization (per log)
98  */
99 
100 #define LOGGC_LOCK_INIT(log)	spin_lock_init(&(log)->gclock)
101 #define LOGGC_LOCK(log)		spin_lock_irq(&(log)->gclock)
102 #define LOGGC_UNLOCK(log)	spin_unlock_irq(&(log)->gclock)
103 #define LOGGC_WAKEUP(tblk)	wake_up_all(&(tblk)->gcwait)
104 
105 /*
106  *	log sync serialization (per log)
107  */
108 #define	LOGSYNC_DELTA(logsize)		min((logsize)/8, 128*LOGPSIZE)
109 #define	LOGSYNC_BARRIER(logsize)	((logsize)/4)
110 /*
111 #define	LOGSYNC_DELTA(logsize)		min((logsize)/4, 256*LOGPSIZE)
112 #define	LOGSYNC_BARRIER(logsize)	((logsize)/2)
113 */
114 
115 
116 /*
117  *	log buffer cache synchronization
118  */
119 static DEFINE_SPINLOCK(jfsLCacheLock);
120 
121 #define	LCACHE_LOCK(flags)	spin_lock_irqsave(&jfsLCacheLock, flags)
122 #define	LCACHE_UNLOCK(flags)	spin_unlock_irqrestore(&jfsLCacheLock, flags)
123 
124 /*
125  * See __SLEEP_COND in jfs_locks.h
126  */
127 #define LCACHE_SLEEP_COND(wq, cond, flags)	\
128 do {						\
129 	if (cond)				\
130 		break;				\
131 	__SLEEP_COND(wq, cond, LCACHE_LOCK(flags), LCACHE_UNLOCK(flags)); \
132 } while (0)
133 
134 #define	LCACHE_WAKEUP(event)	wake_up(event)
135 
136 
137 /*
138  *	lbuf buffer cache (lCache) control
139  */
140 /* log buffer manager pageout control (cumulative, inclusive) */
141 #define	lbmREAD		0x0001
142 #define	lbmWRITE	0x0002	/* enqueue at tail of write queue;
143 				 * init pageout if at head of queue;
144 				 */
145 #define	lbmRELEASE	0x0004	/* remove from write queue
146 				 * at completion of pageout;
147 				 * do not free/recycle it yet:
148 				 * caller will free it;
149 				 */
150 #define	lbmSYNC		0x0008	/* do not return to freelist
151 				 * when removed from write queue;
152 				 */
153 #define lbmFREE		0x0010	/* return to freelist
154 				 * at completion of pageout;
155 				 * the buffer may be recycled;
156 				 */
157 #define	lbmDONE		0x0020
158 #define	lbmERROR	0x0040
159 #define lbmGC		0x0080	/* lbmIODone to perform post-GC processing
160 				 * of log page
161 				 */
162 #define lbmDIRECT	0x0100
163 
164 /*
165  * Global list of active external journals
166  */
167 static LIST_HEAD(jfs_external_logs);
168 static struct jfs_log *dummy_log = NULL;
169 static DEFINE_MUTEX(jfs_log_mutex);
170 
171 /*
172  * forward references
173  */
174 static int lmWriteRecord(struct jfs_log * log, struct tblock * tblk,
175 			 struct lrd * lrd, struct tlock * tlck);
176 
177 static int lmNextPage(struct jfs_log * log);
178 static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
179 			   int activate);
180 
181 static int open_inline_log(struct super_block *sb);
182 static int open_dummy_log(struct super_block *sb);
183 static int lbmLogInit(struct jfs_log * log);
184 static void lbmLogShutdown(struct jfs_log * log);
185 static struct lbuf *lbmAllocate(struct jfs_log * log, int);
186 static void lbmFree(struct lbuf * bp);
187 static void lbmfree(struct lbuf * bp);
188 static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp);
189 static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag, int cant_block);
190 static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag);
191 static int lbmIOWait(struct lbuf * bp, int flag);
192 static bio_end_io_t lbmIODone;
193 static void lbmStartIO(struct lbuf * bp);
194 static void lmGCwrite(struct jfs_log * log, int cant_block);
195 static int lmLogSync(struct jfs_log * log, int hard_sync);
196 
197 
198 
199 /*
200  *	statistics
201  */
202 #ifdef CONFIG_JFS_STATISTICS
203 static struct lmStat {
204 	uint commit;		/* # of commit */
205 	uint pagedone;		/* # of page written */
206 	uint submitted;		/* # of pages submitted */
207 	uint full_page;		/* # of full pages submitted */
208 	uint partial_page;	/* # of partial pages submitted */
209 } lmStat;
210 #endif
211 
212 static void write_special_inodes(struct jfs_log *log,
213 				 int (*writer)(struct address_space *))
214 {
215 	struct jfs_sb_info *sbi;
216 
217 	list_for_each_entry(sbi, &log->sb_list, log_list) {
218 		writer(sbi->ipbmap->i_mapping);
219 		writer(sbi->ipimap->i_mapping);
220 		writer(sbi->direct_inode->i_mapping);
221 	}
222 }
223 
224 /*
225  * NAME:	lmLog()
226  *
227  * FUNCTION:	write a log record;
228  *
229  * PARAMETER:
230  *
231  * RETURN:	lsn - offset to the next log record to write (end-of-log);
232  *		-1  - error;
233  *
234  * note: todo: log error handler
235  */
236 int lmLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
237 	  struct tlock * tlck)
238 {
239 	int lsn;
240 	int diffp, difft;
241 	struct metapage *mp = NULL;
242 	unsigned long flags;
243 
244 	jfs_info("lmLog: log:0x%p tblk:0x%p, lrd:0x%p tlck:0x%p",
245 		 log, tblk, lrd, tlck);
246 
247 	LOG_LOCK(log);
248 
249 	/* log by (out-of-transaction) JFS ? */
250 	if (tblk == NULL)
251 		goto writeRecord;
252 
253 	/* log from page ? */
254 	if (tlck == NULL ||
255 	    tlck->type & tlckBTROOT || (mp = tlck->mp) == NULL)
256 		goto writeRecord;
257 
258 	/*
259 	 *	initialize/update page/transaction recovery lsn
260 	 */
261 	lsn = log->lsn;
262 
263 	LOGSYNC_LOCK(log, flags);
264 
265 	/*
266 	 * initialize page lsn if first log write of the page
267 	 */
268 	if (mp->lsn == 0) {
269 		mp->log = log;
270 		mp->lsn = lsn;
271 		log->count++;
272 
273 		/* insert page at tail of logsynclist */
274 		list_add_tail(&mp->synclist, &log->synclist);
275 	}
276 
277 	/*
278 	 *	initialize/update lsn of tblock of the page
279 	 *
280 	 * transaction inherits oldest lsn of pages associated
281 	 * with allocation/deallocation of resources (their
282 	 * log records are used to reconstruct allocation map
283 	 * at recovery time: inode for inode allocation map,
284 	 * B+-tree index of extent descriptors for block
285 	 * allocation map);
286 	 * allocation map pages inherit transaction lsn at
287 	 * commit time to allow forwarding log syncpt past log
288 	 * records associated with allocation/deallocation of
289 	 * resources only after persistent map of these map pages
290 	 * have been updated and propagated to home.
291 	 */
292 	/*
293 	 * initialize transaction lsn:
294 	 */
295 	if (tblk->lsn == 0) {
296 		/* inherit lsn of its first page logged */
297 		tblk->lsn = mp->lsn;
298 		log->count++;
299 
300 		/* insert tblock after the page on logsynclist */
301 		list_add(&tblk->synclist, &mp->synclist);
302 	}
303 	/*
304 	 * update transaction lsn:
305 	 */
306 	else {
307 		/* inherit oldest/smallest lsn of page */
308 		logdiff(diffp, mp->lsn, log);
309 		logdiff(difft, tblk->lsn, log);
310 		if (diffp < difft) {
311 			/* update tblock lsn with page lsn */
312 			tblk->lsn = mp->lsn;
313 
314 			/* move tblock after page on logsynclist */
315 			list_move(&tblk->synclist, &mp->synclist);
316 		}
317 	}
318 
319 	LOGSYNC_UNLOCK(log, flags);
320 
321 	/*
322 	 *	write the log record
323 	 */
324       writeRecord:
325 	lsn = lmWriteRecord(log, tblk, lrd, tlck);
326 
327 	/*
328 	 * forward log syncpt if log reached next syncpt trigger
329 	 */
330 	logdiff(diffp, lsn, log);
331 	if (diffp >= log->nextsync)
332 		lsn = lmLogSync(log, 0);
333 
334 	/* update end-of-log lsn */
335 	log->lsn = lsn;
336 
337 	LOG_UNLOCK(log);
338 
339 	/* return end-of-log address */
340 	return lsn;
341 }
342 
343 /*
344  * NAME:	lmWriteRecord()
345  *
346  * FUNCTION:	move the log record to current log page
347  *
348  * PARAMETER:	cd	- commit descriptor
349  *
350  * RETURN:	end-of-log address
351  *
352  * serialization: LOG_LOCK() held on entry/exit
353  */
354 static int
355 lmWriteRecord(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
356 	      struct tlock * tlck)
357 {
358 	int lsn = 0;		/* end-of-log address */
359 	struct lbuf *bp;	/* dst log page buffer */
360 	struct logpage *lp;	/* dst log page */
361 	caddr_t dst;		/* destination address in log page */
362 	int dstoffset;		/* end-of-log offset in log page */
363 	int freespace;		/* free space in log page */
364 	caddr_t p;		/* src meta-data page */
365 	caddr_t src;
366 	int srclen;
367 	int nbytes;		/* number of bytes to move */
368 	int i;
369 	int len;
370 	struct linelock *linelock;
371 	struct lv *lv;
372 	struct lvd *lvd;
373 	int l2linesize;
374 
375 	len = 0;
376 
377 	/* retrieve destination log page to write */
378 	bp = (struct lbuf *) log->bp;
379 	lp = (struct logpage *) bp->l_ldata;
380 	dstoffset = log->eor;
381 
382 	/* any log data to write ? */
383 	if (tlck == NULL)
384 		goto moveLrd;
385 
386 	/*
387 	 *	move log record data
388 	 */
389 	/* retrieve source meta-data page to log */
390 	if (tlck->flag & tlckPAGELOCK) {
391 		p = (caddr_t) (tlck->mp->data);
392 		linelock = (struct linelock *) & tlck->lock;
393 	}
394 	/* retrieve source in-memory inode to log */
395 	else if (tlck->flag & tlckINODELOCK) {
396 		if (tlck->type & tlckDTREE)
397 			p = (caddr_t) &JFS_IP(tlck->ip)->i_dtroot;
398 		else
399 			p = (caddr_t) &JFS_IP(tlck->ip)->i_xtroot;
400 		linelock = (struct linelock *) & tlck->lock;
401 	}
402 #ifdef	_JFS_WIP
403 	else if (tlck->flag & tlckINLINELOCK) {
404 
405 		inlinelock = (struct inlinelock *) & tlck;
406 		p = (caddr_t) & inlinelock->pxd;
407 		linelock = (struct linelock *) & tlck;
408 	}
409 #endif				/* _JFS_WIP */
410 	else {
411 		jfs_err("lmWriteRecord: UFO tlck:0x%p", tlck);
412 		return 0;	/* Probably should trap */
413 	}
414 	l2linesize = linelock->l2linesize;
415 
416       moveData:
417 	ASSERT(linelock->index <= linelock->maxcnt);
418 
419 	lv = linelock->lv;
420 	for (i = 0; i < linelock->index; i++, lv++) {
421 		if (lv->length == 0)
422 			continue;
423 
424 		/* is page full ? */
425 		if (dstoffset >= LOGPSIZE - LOGPTLRSIZE) {
426 			/* page become full: move on to next page */
427 			lmNextPage(log);
428 
429 			bp = log->bp;
430 			lp = (struct logpage *) bp->l_ldata;
431 			dstoffset = LOGPHDRSIZE;
432 		}
433 
434 		/*
435 		 * move log vector data
436 		 */
437 		src = (u8 *) p + (lv->offset << l2linesize);
438 		srclen = lv->length << l2linesize;
439 		len += srclen;
440 		while (srclen > 0) {
441 			freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
442 			nbytes = min(freespace, srclen);
443 			dst = (caddr_t) lp + dstoffset;
444 			memcpy(dst, src, nbytes);
445 			dstoffset += nbytes;
446 
447 			/* is page not full ? */
448 			if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
449 				break;
450 
451 			/* page become full: move on to next page */
452 			lmNextPage(log);
453 
454 			bp = (struct lbuf *) log->bp;
455 			lp = (struct logpage *) bp->l_ldata;
456 			dstoffset = LOGPHDRSIZE;
457 
458 			srclen -= nbytes;
459 			src += nbytes;
460 		}
461 
462 		/*
463 		 * move log vector descriptor
464 		 */
465 		len += 4;
466 		lvd = (struct lvd *) ((caddr_t) lp + dstoffset);
467 		lvd->offset = cpu_to_le16(lv->offset);
468 		lvd->length = cpu_to_le16(lv->length);
469 		dstoffset += 4;
470 		jfs_info("lmWriteRecord: lv offset:%d length:%d",
471 			 lv->offset, lv->length);
472 	}
473 
474 	if ((i = linelock->next)) {
475 		linelock = (struct linelock *) lid_to_tlock(i);
476 		goto moveData;
477 	}
478 
479 	/*
480 	 *	move log record descriptor
481 	 */
482       moveLrd:
483 	lrd->length = cpu_to_le16(len);
484 
485 	src = (caddr_t) lrd;
486 	srclen = LOGRDSIZE;
487 
488 	while (srclen > 0) {
489 		freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
490 		nbytes = min(freespace, srclen);
491 		dst = (caddr_t) lp + dstoffset;
492 		memcpy(dst, src, nbytes);
493 
494 		dstoffset += nbytes;
495 		srclen -= nbytes;
496 
497 		/* are there more to move than freespace of page ? */
498 		if (srclen)
499 			goto pageFull;
500 
501 		/*
502 		 * end of log record descriptor
503 		 */
504 
505 		/* update last log record eor */
506 		log->eor = dstoffset;
507 		bp->l_eor = dstoffset;
508 		lsn = (log->page << L2LOGPSIZE) + dstoffset;
509 
510 		if (lrd->type & cpu_to_le16(LOG_COMMIT)) {
511 			tblk->clsn = lsn;
512 			jfs_info("wr: tclsn:0x%x, beor:0x%x", tblk->clsn,
513 				 bp->l_eor);
514 
515 			INCREMENT(lmStat.commit);	/* # of commit */
516 
517 			/*
518 			 * enqueue tblock for group commit:
519 			 *
520 			 * enqueue tblock of non-trivial/synchronous COMMIT
521 			 * at tail of group commit queue
522 			 * (trivial/asynchronous COMMITs are ignored by
523 			 * group commit.)
524 			 */
525 			LOGGC_LOCK(log);
526 
527 			/* init tblock gc state */
528 			tblk->flag = tblkGC_QUEUE;
529 			tblk->bp = log->bp;
530 			tblk->pn = log->page;
531 			tblk->eor = log->eor;
532 
533 			/* enqueue transaction to commit queue */
534 			list_add_tail(&tblk->cqueue, &log->cqueue);
535 
536 			LOGGC_UNLOCK(log);
537 		}
538 
539 		jfs_info("lmWriteRecord: lrd:0x%04x bp:0x%p pn:%d eor:0x%x",
540 			le16_to_cpu(lrd->type), log->bp, log->page, dstoffset);
541 
542 		/* page not full ? */
543 		if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
544 			return lsn;
545 
546 	      pageFull:
547 		/* page become full: move on to next page */
548 		lmNextPage(log);
549 
550 		bp = (struct lbuf *) log->bp;
551 		lp = (struct logpage *) bp->l_ldata;
552 		dstoffset = LOGPHDRSIZE;
553 		src += nbytes;
554 	}
555 
556 	return lsn;
557 }
558 
559 
560 /*
561  * NAME:	lmNextPage()
562  *
563  * FUNCTION:	write current page and allocate next page.
564  *
565  * PARAMETER:	log
566  *
567  * RETURN:	0
568  *
569  * serialization: LOG_LOCK() held on entry/exit
570  */
571 static int lmNextPage(struct jfs_log * log)
572 {
573 	struct logpage *lp;
574 	int lspn;		/* log sequence page number */
575 	int pn;			/* current page number */
576 	struct lbuf *bp;
577 	struct lbuf *nextbp;
578 	struct tblock *tblk;
579 
580 	/* get current log page number and log sequence page number */
581 	pn = log->page;
582 	bp = log->bp;
583 	lp = (struct logpage *) bp->l_ldata;
584 	lspn = le32_to_cpu(lp->h.page);
585 
586 	LOGGC_LOCK(log);
587 
588 	/*
589 	 *	write or queue the full page at the tail of write queue
590 	 */
591 	/* get the tail tblk on commit queue */
592 	if (list_empty(&log->cqueue))
593 		tblk = NULL;
594 	else
595 		tblk = list_entry(log->cqueue.prev, struct tblock, cqueue);
596 
597 	/* every tblk who has COMMIT record on the current page,
598 	 * and has not been committed, must be on commit queue
599 	 * since tblk is queued at commit queueu at the time
600 	 * of writing its COMMIT record on the page before
601 	 * page becomes full (even though the tblk thread
602 	 * who wrote COMMIT record may have been suspended
603 	 * currently);
604 	 */
605 
606 	/* is page bound with outstanding tail tblk ? */
607 	if (tblk && tblk->pn == pn) {
608 		/* mark tblk for end-of-page */
609 		tblk->flag |= tblkGC_EOP;
610 
611 		if (log->cflag & logGC_PAGEOUT) {
612 			/* if page is not already on write queue,
613 			 * just enqueue (no lbmWRITE to prevent redrive)
614 			 * buffer to wqueue to ensure correct serial order
615 			 * of the pages since log pages will be added
616 			 * continuously
617 			 */
618 			if (bp->l_wqnext == NULL)
619 				lbmWrite(log, bp, 0, 0);
620 		} else {
621 			/*
622 			 * No current GC leader, initiate group commit
623 			 */
624 			log->cflag |= logGC_PAGEOUT;
625 			lmGCwrite(log, 0);
626 		}
627 	}
628 	/* page is not bound with outstanding tblk:
629 	 * init write or mark it to be redriven (lbmWRITE)
630 	 */
631 	else {
632 		/* finalize the page */
633 		bp->l_ceor = bp->l_eor;
634 		lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
635 		lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE, 0);
636 	}
637 	LOGGC_UNLOCK(log);
638 
639 	/*
640 	 *	allocate/initialize next page
641 	 */
642 	/* if log wraps, the first data page of log is 2
643 	 * (0 never used, 1 is superblock).
644 	 */
645 	log->page = (pn == log->size - 1) ? 2 : pn + 1;
646 	log->eor = LOGPHDRSIZE;	/* ? valid page empty/full at logRedo() */
647 
648 	/* allocate/initialize next log page buffer */
649 	nextbp = lbmAllocate(log, log->page);
650 	nextbp->l_eor = log->eor;
651 	log->bp = nextbp;
652 
653 	/* initialize next log page */
654 	lp = (struct logpage *) nextbp->l_ldata;
655 	lp->h.page = lp->t.page = cpu_to_le32(lspn + 1);
656 	lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
657 
658 	return 0;
659 }
660 
661 
662 /*
663  * NAME:	lmGroupCommit()
664  *
665  * FUNCTION:	group commit
666  *	initiate pageout of the pages with COMMIT in the order of
667  *	page number - redrive pageout of the page at the head of
668  *	pageout queue until full page has been written.
669  *
670  * RETURN:
671  *
672  * NOTE:
673  *	LOGGC_LOCK serializes log group commit queue, and
674  *	transaction blocks on the commit queue.
675  *	N.B. LOG_LOCK is NOT held during lmGroupCommit().
676  */
677 int lmGroupCommit(struct jfs_log * log, struct tblock * tblk)
678 {
679 	int rc = 0;
680 
681 	LOGGC_LOCK(log);
682 
683 	/* group committed already ? */
684 	if (tblk->flag & tblkGC_COMMITTED) {
685 		if (tblk->flag & tblkGC_ERROR)
686 			rc = -EIO;
687 
688 		LOGGC_UNLOCK(log);
689 		return rc;
690 	}
691 	jfs_info("lmGroup Commit: tblk = 0x%p, gcrtc = %d", tblk, log->gcrtc);
692 
693 	if (tblk->xflag & COMMIT_LAZY)
694 		tblk->flag |= tblkGC_LAZY;
695 
696 	if ((!(log->cflag & logGC_PAGEOUT)) && (!list_empty(&log->cqueue)) &&
697 	    (!(tblk->xflag & COMMIT_LAZY) || test_bit(log_FLUSH, &log->flag)
698 	     || jfs_tlocks_low)) {
699 		/*
700 		 * No pageout in progress
701 		 *
702 		 * start group commit as its group leader.
703 		 */
704 		log->cflag |= logGC_PAGEOUT;
705 
706 		lmGCwrite(log, 0);
707 	}
708 
709 	if (tblk->xflag & COMMIT_LAZY) {
710 		/*
711 		 * Lazy transactions can leave now
712 		 */
713 		LOGGC_UNLOCK(log);
714 		return 0;
715 	}
716 
717 	/* lmGCwrite gives up LOGGC_LOCK, check again */
718 
719 	if (tblk->flag & tblkGC_COMMITTED) {
720 		if (tblk->flag & tblkGC_ERROR)
721 			rc = -EIO;
722 
723 		LOGGC_UNLOCK(log);
724 		return rc;
725 	}
726 
727 	/* upcount transaction waiting for completion
728 	 */
729 	log->gcrtc++;
730 	tblk->flag |= tblkGC_READY;
731 
732 	__SLEEP_COND(tblk->gcwait, (tblk->flag & tblkGC_COMMITTED),
733 		     LOGGC_LOCK(log), LOGGC_UNLOCK(log));
734 
735 	/* removed from commit queue */
736 	if (tblk->flag & tblkGC_ERROR)
737 		rc = -EIO;
738 
739 	LOGGC_UNLOCK(log);
740 	return rc;
741 }
742 
743 /*
744  * NAME:	lmGCwrite()
745  *
746  * FUNCTION:	group commit write
747  *	initiate write of log page, building a group of all transactions
748  *	with commit records on that page.
749  *
750  * RETURN:	None
751  *
752  * NOTE:
753  *	LOGGC_LOCK must be held by caller.
754  *	N.B. LOG_LOCK is NOT held during lmGroupCommit().
755  */
756 static void lmGCwrite(struct jfs_log * log, int cant_write)
757 {
758 	struct lbuf *bp;
759 	struct logpage *lp;
760 	int gcpn;		/* group commit page number */
761 	struct tblock *tblk;
762 	struct tblock *xtblk = NULL;
763 
764 	/*
765 	 * build the commit group of a log page
766 	 *
767 	 * scan commit queue and make a commit group of all
768 	 * transactions with COMMIT records on the same log page.
769 	 */
770 	/* get the head tblk on the commit queue */
771 	gcpn = list_entry(log->cqueue.next, struct tblock, cqueue)->pn;
772 
773 	list_for_each_entry(tblk, &log->cqueue, cqueue) {
774 		if (tblk->pn != gcpn)
775 			break;
776 
777 		xtblk = tblk;
778 
779 		/* state transition: (QUEUE, READY) -> COMMIT */
780 		tblk->flag |= tblkGC_COMMIT;
781 	}
782 	tblk = xtblk;		/* last tblk of the page */
783 
784 	/*
785 	 * pageout to commit transactions on the log page.
786 	 */
787 	bp = (struct lbuf *) tblk->bp;
788 	lp = (struct logpage *) bp->l_ldata;
789 	/* is page already full ? */
790 	if (tblk->flag & tblkGC_EOP) {
791 		/* mark page to free at end of group commit of the page */
792 		tblk->flag &= ~tblkGC_EOP;
793 		tblk->flag |= tblkGC_FREE;
794 		bp->l_ceor = bp->l_eor;
795 		lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
796 		lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmGC,
797 			 cant_write);
798 		INCREMENT(lmStat.full_page);
799 	}
800 	/* page is not yet full */
801 	else {
802 		bp->l_ceor = tblk->eor;	/* ? bp->l_ceor = bp->l_eor; */
803 		lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
804 		lbmWrite(log, bp, lbmWRITE | lbmGC, cant_write);
805 		INCREMENT(lmStat.partial_page);
806 	}
807 }
808 
809 /*
810  * NAME:	lmPostGC()
811  *
812  * FUNCTION:	group commit post-processing
813  *	Processes transactions after their commit records have been written
814  *	to disk, redriving log I/O if necessary.
815  *
816  * RETURN:	None
817  *
818  * NOTE:
819  *	This routine is called a interrupt time by lbmIODone
820  */
821 static void lmPostGC(struct lbuf * bp)
822 {
823 	unsigned long flags;
824 	struct jfs_log *log = bp->l_log;
825 	struct logpage *lp;
826 	struct tblock *tblk, *temp;
827 
828 	//LOGGC_LOCK(log);
829 	spin_lock_irqsave(&log->gclock, flags);
830 	/*
831 	 * current pageout of group commit completed.
832 	 *
833 	 * remove/wakeup transactions from commit queue who were
834 	 * group committed with the current log page
835 	 */
836 	list_for_each_entry_safe(tblk, temp, &log->cqueue, cqueue) {
837 		if (!(tblk->flag & tblkGC_COMMIT))
838 			break;
839 		/* if transaction was marked GC_COMMIT then
840 		 * it has been shipped in the current pageout
841 		 * and made it to disk - it is committed.
842 		 */
843 
844 		if (bp->l_flag & lbmERROR)
845 			tblk->flag |= tblkGC_ERROR;
846 
847 		/* remove it from the commit queue */
848 		list_del(&tblk->cqueue);
849 		tblk->flag &= ~tblkGC_QUEUE;
850 
851 		if (tblk == log->flush_tblk) {
852 			/* we can stop flushing the log now */
853 			clear_bit(log_FLUSH, &log->flag);
854 			log->flush_tblk = NULL;
855 		}
856 
857 		jfs_info("lmPostGC: tblk = 0x%p, flag = 0x%x", tblk,
858 			 tblk->flag);
859 
860 		if (!(tblk->xflag & COMMIT_FORCE))
861 			/*
862 			 * Hand tblk over to lazy commit thread
863 			 */
864 			txLazyUnlock(tblk);
865 		else {
866 			/* state transition: COMMIT -> COMMITTED */
867 			tblk->flag |= tblkGC_COMMITTED;
868 
869 			if (tblk->flag & tblkGC_READY)
870 				log->gcrtc--;
871 
872 			LOGGC_WAKEUP(tblk);
873 		}
874 
875 		/* was page full before pageout ?
876 		 * (and this is the last tblk bound with the page)
877 		 */
878 		if (tblk->flag & tblkGC_FREE)
879 			lbmFree(bp);
880 		/* did page become full after pageout ?
881 		 * (and this is the last tblk bound with the page)
882 		 */
883 		else if (tblk->flag & tblkGC_EOP) {
884 			/* finalize the page */
885 			lp = (struct logpage *) bp->l_ldata;
886 			bp->l_ceor = bp->l_eor;
887 			lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
888 			jfs_info("lmPostGC: calling lbmWrite");
889 			lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE,
890 				 1);
891 		}
892 
893 	}
894 
895 	/* are there any transactions who have entered lnGroupCommit()
896 	 * (whose COMMITs are after that of the last log page written.
897 	 * They are waiting for new group commit (above at (SLEEP 1))
898 	 * or lazy transactions are on a full (queued) log page,
899 	 * select the latest ready transaction as new group leader and
900 	 * wake her up to lead her group.
901 	 */
902 	if ((!list_empty(&log->cqueue)) &&
903 	    ((log->gcrtc > 0) || (tblk->bp->l_wqnext != NULL) ||
904 	     test_bit(log_FLUSH, &log->flag) || jfs_tlocks_low))
905 		/*
906 		 * Call lmGCwrite with new group leader
907 		 */
908 		lmGCwrite(log, 1);
909 
910 	/* no transaction are ready yet (transactions are only just
911 	 * queued (GC_QUEUE) and not entered for group commit yet).
912 	 * the first transaction entering group commit
913 	 * will elect herself as new group leader.
914 	 */
915 	else
916 		log->cflag &= ~logGC_PAGEOUT;
917 
918 	//LOGGC_UNLOCK(log);
919 	spin_unlock_irqrestore(&log->gclock, flags);
920 	return;
921 }
922 
923 /*
924  * NAME:	lmLogSync()
925  *
926  * FUNCTION:	write log SYNCPT record for specified log
927  *	if new sync address is available
928  *	(normally the case if sync() is executed by back-ground
929  *	process).
930  *	calculate new value of i_nextsync which determines when
931  *	this code is called again.
932  *
933  * PARAMETERS:	log	- log structure
934  *		hard_sync - 1 to force all metadata to be written
935  *
936  * RETURN:	0
937  *
938  * serialization: LOG_LOCK() held on entry/exit
939  */
940 static int lmLogSync(struct jfs_log * log, int hard_sync)
941 {
942 	int logsize;
943 	int written;		/* written since last syncpt */
944 	int free;		/* free space left available */
945 	int delta;		/* additional delta to write normally */
946 	int more;		/* additional write granted */
947 	struct lrd lrd;
948 	int lsn;
949 	struct logsyncblk *lp;
950 	unsigned long flags;
951 
952 	/* push dirty metapages out to disk */
953 	if (hard_sync)
954 		write_special_inodes(log, filemap_fdatawrite);
955 	else
956 		write_special_inodes(log, filemap_flush);
957 
958 	/*
959 	 *	forward syncpt
960 	 */
961 	/* if last sync is same as last syncpt,
962 	 * invoke sync point forward processing to update sync.
963 	 */
964 
965 	if (log->sync == log->syncpt) {
966 		LOGSYNC_LOCK(log, flags);
967 		if (list_empty(&log->synclist))
968 			log->sync = log->lsn;
969 		else {
970 			lp = list_entry(log->synclist.next,
971 					struct logsyncblk, synclist);
972 			log->sync = lp->lsn;
973 		}
974 		LOGSYNC_UNLOCK(log, flags);
975 
976 	}
977 
978 	/* if sync is different from last syncpt,
979 	 * write a SYNCPT record with syncpt = sync.
980 	 * reset syncpt = sync
981 	 */
982 	if (log->sync != log->syncpt) {
983 		lrd.logtid = 0;
984 		lrd.backchain = 0;
985 		lrd.type = cpu_to_le16(LOG_SYNCPT);
986 		lrd.length = 0;
987 		lrd.log.syncpt.sync = cpu_to_le32(log->sync);
988 		lsn = lmWriteRecord(log, NULL, &lrd, NULL);
989 
990 		log->syncpt = log->sync;
991 	} else
992 		lsn = log->lsn;
993 
994 	/*
995 	 *	setup next syncpt trigger (SWAG)
996 	 */
997 	logsize = log->logsize;
998 
999 	logdiff(written, lsn, log);
1000 	free = logsize - written;
1001 	delta = LOGSYNC_DELTA(logsize);
1002 	more = min(free / 2, delta);
1003 	if (more < 2 * LOGPSIZE) {
1004 		jfs_warn("\n ... Log Wrap ... Log Wrap ... Log Wrap ...\n");
1005 		/*
1006 		 *	log wrapping
1007 		 *
1008 		 * option 1 - panic ? No.!
1009 		 * option 2 - shutdown file systems
1010 		 *	      associated with log ?
1011 		 * option 3 - extend log ?
1012 		 */
1013 		/*
1014 		 * option 4 - second chance
1015 		 *
1016 		 * mark log wrapped, and continue.
1017 		 * when all active transactions are completed,
1018 		 * mark log vaild for recovery.
1019 		 * if crashed during invalid state, log state
1020 		 * implies invald 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 	lmLogSync(log, hard_sync);
1062 	LOG_UNLOCK(log);
1063 }
1064 
1065 /*
1066  * NAME:	lmLogOpen()
1067  *
1068  * FUNCTION:	open the log on first open;
1069  *	insert filesystem in the active list of the log.
1070  *
1071  * PARAMETER:	ipmnt	- file system mount inode
1072  *		iplog	- log inode (out)
1073  *
1074  * RETURN:
1075  *
1076  * serialization:
1077  */
1078 int lmLogOpen(struct super_block *sb)
1079 {
1080 	int rc;
1081 	struct block_device *bdev;
1082 	struct jfs_log *log;
1083 	struct jfs_sb_info *sbi = JFS_SBI(sb);
1084 
1085 	if (sbi->flag & JFS_NOINTEGRITY)
1086 		return open_dummy_log(sb);
1087 
1088 	if (sbi->mntflag & JFS_INLINELOG)
1089 		return open_inline_log(sb);
1090 
1091 	mutex_lock(&jfs_log_mutex);
1092 	list_for_each_entry(log, &jfs_external_logs, journal_list) {
1093 		if (log->bdev->bd_dev == sbi->logdev) {
1094 			if (memcmp(log->uuid, sbi->loguuid,
1095 				   sizeof(log->uuid))) {
1096 				jfs_warn("wrong uuid on JFS journal\n");
1097 				mutex_unlock(&jfs_log_mutex);
1098 				return -EINVAL;
1099 			}
1100 			/*
1101 			 * add file system to log active file system list
1102 			 */
1103 			if ((rc = lmLogFileSystem(log, sbi, 1))) {
1104 				mutex_unlock(&jfs_log_mutex);
1105 				return rc;
1106 			}
1107 			goto journal_found;
1108 		}
1109 	}
1110 
1111 	if (!(log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL))) {
1112 		mutex_unlock(&jfs_log_mutex);
1113 		return -ENOMEM;
1114 	}
1115 	INIT_LIST_HEAD(&log->sb_list);
1116 	init_waitqueue_head(&log->syncwait);
1117 
1118 	/*
1119 	 *	external log as separate logical volume
1120 	 *
1121 	 * file systems to log may have n-to-1 relationship;
1122 	 */
1123 
1124 	bdev = open_by_devnum(sbi->logdev, FMODE_READ|FMODE_WRITE);
1125 	if (IS_ERR(bdev)) {
1126 		rc = -PTR_ERR(bdev);
1127 		goto free;
1128 	}
1129 
1130 	if ((rc = bd_claim(bdev, log))) {
1131 		goto close;
1132 	}
1133 
1134 	log->bdev = bdev;
1135 	memcpy(log->uuid, sbi->loguuid, sizeof(log->uuid));
1136 
1137 	/*
1138 	 * initialize log:
1139 	 */
1140 	if ((rc = lmLogInit(log)))
1141 		goto unclaim;
1142 
1143 	list_add(&log->journal_list, &jfs_external_logs);
1144 
1145 	/*
1146 	 * add file system to log active file system list
1147 	 */
1148 	if ((rc = lmLogFileSystem(log, sbi, 1)))
1149 		goto shutdown;
1150 
1151 journal_found:
1152 	LOG_LOCK(log);
1153 	list_add(&sbi->log_list, &log->sb_list);
1154 	sbi->log = log;
1155 	LOG_UNLOCK(log);
1156 
1157 	mutex_unlock(&jfs_log_mutex);
1158 	return 0;
1159 
1160 	/*
1161 	 *	unwind on error
1162 	 */
1163       shutdown:		/* unwind lbmLogInit() */
1164 	list_del(&log->journal_list);
1165 	lbmLogShutdown(log);
1166 
1167       unclaim:
1168 	bd_release(bdev);
1169 
1170       close:		/* close external log device */
1171 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1172 
1173       free:		/* free log descriptor */
1174 	mutex_unlock(&jfs_log_mutex);
1175 	kfree(log);
1176 
1177 	jfs_warn("lmLogOpen: exit(%d)", rc);
1178 	return rc;
1179 }
1180 
1181 static int open_inline_log(struct super_block *sb)
1182 {
1183 	struct jfs_log *log;
1184 	int rc;
1185 
1186 	if (!(log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL)))
1187 		return -ENOMEM;
1188 	INIT_LIST_HEAD(&log->sb_list);
1189 	init_waitqueue_head(&log->syncwait);
1190 
1191 	set_bit(log_INLINELOG, &log->flag);
1192 	log->bdev = sb->s_bdev;
1193 	log->base = addressPXD(&JFS_SBI(sb)->logpxd);
1194 	log->size = lengthPXD(&JFS_SBI(sb)->logpxd) >>
1195 	    (L2LOGPSIZE - sb->s_blocksize_bits);
1196 	log->l2bsize = sb->s_blocksize_bits;
1197 	ASSERT(L2LOGPSIZE >= sb->s_blocksize_bits);
1198 
1199 	/*
1200 	 * initialize log.
1201 	 */
1202 	if ((rc = lmLogInit(log))) {
1203 		kfree(log);
1204 		jfs_warn("lmLogOpen: exit(%d)", rc);
1205 		return rc;
1206 	}
1207 
1208 	list_add(&JFS_SBI(sb)->log_list, &log->sb_list);
1209 	JFS_SBI(sb)->log = log;
1210 
1211 	return rc;
1212 }
1213 
1214 static int open_dummy_log(struct super_block *sb)
1215 {
1216 	int rc;
1217 
1218 	mutex_lock(&jfs_log_mutex);
1219 	if (!dummy_log) {
1220 		dummy_log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL);
1221 		if (!dummy_log) {
1222 			mutex_unlock(&jfs_log_mutex);
1223 			return -ENOMEM;
1224 		}
1225 		INIT_LIST_HEAD(&dummy_log->sb_list);
1226 		init_waitqueue_head(&dummy_log->syncwait);
1227 		dummy_log->no_integrity = 1;
1228 		/* Make up some stuff */
1229 		dummy_log->base = 0;
1230 		dummy_log->size = 1024;
1231 		rc = lmLogInit(dummy_log);
1232 		if (rc) {
1233 			kfree(dummy_log);
1234 			dummy_log = NULL;
1235 			mutex_unlock(&jfs_log_mutex);
1236 			return rc;
1237 		}
1238 	}
1239 
1240 	LOG_LOCK(dummy_log);
1241 	list_add(&JFS_SBI(sb)->log_list, &dummy_log->sb_list);
1242 	JFS_SBI(sb)->log = dummy_log;
1243 	LOG_UNLOCK(dummy_log);
1244 	mutex_unlock(&jfs_log_mutex);
1245 
1246 	return 0;
1247 }
1248 
1249 /*
1250  * NAME:	lmLogInit()
1251  *
1252  * FUNCTION:	log initialization at first log open.
1253  *
1254  *	logredo() (or logformat()) should have been run previously.
1255  *	initialize the log from log superblock.
1256  *	set the log state in the superblock to LOGMOUNT and
1257  *	write SYNCPT log record.
1258  *
1259  * PARAMETER:	log	- log structure
1260  *
1261  * RETURN:	0	- if ok
1262  *		-EINVAL	- bad log magic number or superblock dirty
1263  *		error returned from logwait()
1264  *
1265  * serialization: single first open thread
1266  */
1267 int lmLogInit(struct jfs_log * log)
1268 {
1269 	int rc = 0;
1270 	struct lrd lrd;
1271 	struct logsuper *logsuper;
1272 	struct lbuf *bpsuper;
1273 	struct lbuf *bp;
1274 	struct logpage *lp;
1275 	int lsn = 0;
1276 
1277 	jfs_info("lmLogInit: log:0x%p", log);
1278 
1279 	/* initialize the group commit serialization lock */
1280 	LOGGC_LOCK_INIT(log);
1281 
1282 	/* allocate/initialize the log write serialization lock */
1283 	LOG_LOCK_INIT(log);
1284 
1285 	LOGSYNC_LOCK_INIT(log);
1286 
1287 	INIT_LIST_HEAD(&log->synclist);
1288 
1289 	INIT_LIST_HEAD(&log->cqueue);
1290 	log->flush_tblk = NULL;
1291 
1292 	log->count = 0;
1293 
1294 	/*
1295 	 * initialize log i/o
1296 	 */
1297 	if ((rc = lbmLogInit(log)))
1298 		return rc;
1299 
1300 	if (!test_bit(log_INLINELOG, &log->flag))
1301 		log->l2bsize = L2LOGPSIZE;
1302 
1303 	/* check for disabled journaling to disk */
1304 	if (log->no_integrity) {
1305 		/*
1306 		 * Journal pages will still be filled.  When the time comes
1307 		 * to actually do the I/O, the write is not done, and the
1308 		 * endio routine is called directly.
1309 		 */
1310 		bp = lbmAllocate(log , 0);
1311 		log->bp = bp;
1312 		bp->l_pn = bp->l_eor = 0;
1313 	} else {
1314 		/*
1315 		 * validate log superblock
1316 		 */
1317 		if ((rc = lbmRead(log, 1, &bpsuper)))
1318 			goto errout10;
1319 
1320 		logsuper = (struct logsuper *) bpsuper->l_ldata;
1321 
1322 		if (logsuper->magic != cpu_to_le32(LOGMAGIC)) {
1323 			jfs_warn("*** Log Format Error ! ***");
1324 			rc = -EINVAL;
1325 			goto errout20;
1326 		}
1327 
1328 		/* logredo() should have been run successfully. */
1329 		if (logsuper->state != cpu_to_le32(LOGREDONE)) {
1330 			jfs_warn("*** Log Is Dirty ! ***");
1331 			rc = -EINVAL;
1332 			goto errout20;
1333 		}
1334 
1335 		/* initialize log from log superblock */
1336 		if (test_bit(log_INLINELOG,&log->flag)) {
1337 			if (log->size != le32_to_cpu(logsuper->size)) {
1338 				rc = -EINVAL;
1339 				goto errout20;
1340 			}
1341 			jfs_info("lmLogInit: inline log:0x%p base:0x%Lx "
1342 				 "size:0x%x", log,
1343 				 (unsigned long long) log->base, log->size);
1344 		} else {
1345 			if (memcmp(logsuper->uuid, log->uuid, 16)) {
1346 				jfs_warn("wrong uuid on JFS log device");
1347 				goto errout20;
1348 			}
1349 			log->size = le32_to_cpu(logsuper->size);
1350 			log->l2bsize = le32_to_cpu(logsuper->l2bsize);
1351 			jfs_info("lmLogInit: external log:0x%p base:0x%Lx "
1352 				 "size:0x%x", log,
1353 				 (unsigned long long) log->base, log->size);
1354 		}
1355 
1356 		log->page = le32_to_cpu(logsuper->end) / LOGPSIZE;
1357 		log->eor = le32_to_cpu(logsuper->end) - (LOGPSIZE * log->page);
1358 
1359 		/*
1360 		 * initialize for log append write mode
1361 		 */
1362 		/* establish current/end-of-log page/buffer */
1363 		if ((rc = lbmRead(log, log->page, &bp)))
1364 			goto errout20;
1365 
1366 		lp = (struct logpage *) bp->l_ldata;
1367 
1368 		jfs_info("lmLogInit: lsn:0x%x page:%d eor:%d:%d",
1369 			 le32_to_cpu(logsuper->end), log->page, log->eor,
1370 			 le16_to_cpu(lp->h.eor));
1371 
1372 		log->bp = bp;
1373 		bp->l_pn = log->page;
1374 		bp->l_eor = log->eor;
1375 
1376 		/* if current page is full, move on to next page */
1377 		if (log->eor >= LOGPSIZE - LOGPTLRSIZE)
1378 			lmNextPage(log);
1379 
1380 		/*
1381 		 * initialize log syncpoint
1382 		 */
1383 		/*
1384 		 * write the first SYNCPT record with syncpoint = 0
1385 		 * (i.e., log redo up to HERE !);
1386 		 * remove current page from lbm write queue at end of pageout
1387 		 * (to write log superblock update), but do not release to
1388 		 * freelist;
1389 		 */
1390 		lrd.logtid = 0;
1391 		lrd.backchain = 0;
1392 		lrd.type = cpu_to_le16(LOG_SYNCPT);
1393 		lrd.length = 0;
1394 		lrd.log.syncpt.sync = 0;
1395 		lsn = lmWriteRecord(log, NULL, &lrd, NULL);
1396 		bp = log->bp;
1397 		bp->l_ceor = bp->l_eor;
1398 		lp = (struct logpage *) bp->l_ldata;
1399 		lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
1400 		lbmWrite(log, bp, lbmWRITE | lbmSYNC, 0);
1401 		if ((rc = lbmIOWait(bp, 0)))
1402 			goto errout30;
1403 
1404 		/*
1405 		 * update/write superblock
1406 		 */
1407 		logsuper->state = cpu_to_le32(LOGMOUNT);
1408 		log->serial = le32_to_cpu(logsuper->serial) + 1;
1409 		logsuper->serial = cpu_to_le32(log->serial);
1410 		lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1411 		if ((rc = lbmIOWait(bpsuper, lbmFREE)))
1412 			goto errout30;
1413 	}
1414 
1415 	/* initialize logsync parameters */
1416 	log->logsize = (log->size - 2) << L2LOGPSIZE;
1417 	log->lsn = lsn;
1418 	log->syncpt = lsn;
1419 	log->sync = log->syncpt;
1420 	log->nextsync = LOGSYNC_DELTA(log->logsize);
1421 
1422 	jfs_info("lmLogInit: lsn:0x%x syncpt:0x%x sync:0x%x",
1423 		 log->lsn, log->syncpt, log->sync);
1424 
1425 	/*
1426 	 * initialize for lazy/group commit
1427 	 */
1428 	log->clsn = lsn;
1429 
1430 	return 0;
1431 
1432 	/*
1433 	 *	unwind on error
1434 	 */
1435       errout30:		/* release log page */
1436 	log->wqueue = NULL;
1437 	bp->l_wqnext = NULL;
1438 	lbmFree(bp);
1439 
1440       errout20:		/* release log superblock */
1441 	lbmFree(bpsuper);
1442 
1443       errout10:		/* unwind lbmLogInit() */
1444 	lbmLogShutdown(log);
1445 
1446 	jfs_warn("lmLogInit: exit(%d)", rc);
1447 	return rc;
1448 }
1449 
1450 
1451 /*
1452  * NAME:	lmLogClose()
1453  *
1454  * FUNCTION:	remove file system <ipmnt> from active list of log <iplog>
1455  *		and close it on last close.
1456  *
1457  * PARAMETER:	sb	- superblock
1458  *
1459  * RETURN:	errors from subroutines
1460  *
1461  * serialization:
1462  */
1463 int lmLogClose(struct super_block *sb)
1464 {
1465 	struct jfs_sb_info *sbi = JFS_SBI(sb);
1466 	struct jfs_log *log = sbi->log;
1467 	struct block_device *bdev;
1468 	int rc = 0;
1469 
1470 	jfs_info("lmLogClose: log:0x%p", log);
1471 
1472 	mutex_lock(&jfs_log_mutex);
1473 	LOG_LOCK(log);
1474 	list_del(&sbi->log_list);
1475 	LOG_UNLOCK(log);
1476 	sbi->log = NULL;
1477 
1478 	/*
1479 	 * We need to make sure all of the "written" metapages
1480 	 * actually make it to disk
1481 	 */
1482 	sync_blockdev(sb->s_bdev);
1483 
1484 	if (test_bit(log_INLINELOG, &log->flag)) {
1485 		/*
1486 		 *	in-line log in host file system
1487 		 */
1488 		rc = lmLogShutdown(log);
1489 		kfree(log);
1490 		goto out;
1491 	}
1492 
1493 	if (!log->no_integrity)
1494 		lmLogFileSystem(log, sbi, 0);
1495 
1496 	if (!list_empty(&log->sb_list))
1497 		goto out;
1498 
1499 	/*
1500 	 * TODO: ensure that the dummy_log is in a state to allow
1501 	 * lbmLogShutdown to deallocate all the buffers and call
1502 	 * kfree against dummy_log.  For now, leave dummy_log & its
1503 	 * buffers in memory, and resuse if another no-integrity mount
1504 	 * is requested.
1505 	 */
1506 	if (log->no_integrity)
1507 		goto out;
1508 
1509 	/*
1510 	 *	external log as separate logical volume
1511 	 */
1512 	list_del(&log->journal_list);
1513 	bdev = log->bdev;
1514 	rc = lmLogShutdown(log);
1515 
1516 	bd_release(bdev);
1517 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
1518 
1519 	kfree(log);
1520 
1521       out:
1522 	mutex_unlock(&jfs_log_mutex);
1523 	jfs_info("lmLogClose: exit(%d)", rc);
1524 	return rc;
1525 }
1526 
1527 
1528 /*
1529  * NAME:	jfs_flush_journal()
1530  *
1531  * FUNCTION:	initiate write of any outstanding transactions to the journal
1532  *		and optionally wait until they are all written to disk
1533  *
1534  *		wait == 0  flush until latest txn is committed, don't wait
1535  *		wait == 1  flush until latest txn is committed, wait
1536  *		wait > 1   flush until all txn's are complete, wait
1537  */
1538 void jfs_flush_journal(struct jfs_log *log, int wait)
1539 {
1540 	int i;
1541 	struct tblock *target = NULL;
1542 
1543 	/* jfs_write_inode may call us during read-only mount */
1544 	if (!log)
1545 		return;
1546 
1547 	jfs_info("jfs_flush_journal: log:0x%p wait=%d", log, wait);
1548 
1549 	LOGGC_LOCK(log);
1550 
1551 	if (!list_empty(&log->cqueue)) {
1552 		/*
1553 		 * This ensures that we will keep writing to the journal as long
1554 		 * as there are unwritten commit records
1555 		 */
1556 		target = list_entry(log->cqueue.prev, struct tblock, cqueue);
1557 
1558 		if (test_bit(log_FLUSH, &log->flag)) {
1559 			/*
1560 			 * We're already flushing.
1561 			 * if flush_tblk is NULL, we are flushing everything,
1562 			 * so leave it that way.  Otherwise, update it to the
1563 			 * latest transaction
1564 			 */
1565 			if (log->flush_tblk)
1566 				log->flush_tblk = target;
1567 		} else {
1568 			/* Only flush until latest transaction is committed */
1569 			log->flush_tblk = target;
1570 			set_bit(log_FLUSH, &log->flag);
1571 
1572 			/*
1573 			 * Initiate I/O on outstanding transactions
1574 			 */
1575 			if (!(log->cflag & logGC_PAGEOUT)) {
1576 				log->cflag |= logGC_PAGEOUT;
1577 				lmGCwrite(log, 0);
1578 			}
1579 		}
1580 	}
1581 	if ((wait > 1) || test_bit(log_SYNCBARRIER, &log->flag)) {
1582 		/* Flush until all activity complete */
1583 		set_bit(log_FLUSH, &log->flag);
1584 		log->flush_tblk = NULL;
1585 	}
1586 
1587 	if (wait && target && !(target->flag & tblkGC_COMMITTED)) {
1588 		DECLARE_WAITQUEUE(__wait, current);
1589 
1590 		add_wait_queue(&target->gcwait, &__wait);
1591 		set_current_state(TASK_UNINTERRUPTIBLE);
1592 		LOGGC_UNLOCK(log);
1593 		schedule();
1594 		__set_current_state(TASK_RUNNING);
1595 		LOGGC_LOCK(log);
1596 		remove_wait_queue(&target->gcwait, &__wait);
1597 	}
1598 	LOGGC_UNLOCK(log);
1599 
1600 	if (wait < 2)
1601 		return;
1602 
1603 	write_special_inodes(log, filemap_fdatawrite);
1604 
1605 	/*
1606 	 * If there was recent activity, we may need to wait
1607 	 * for the lazycommit thread to catch up
1608 	 */
1609 	if ((!list_empty(&log->cqueue)) || !list_empty(&log->synclist)) {
1610 		for (i = 0; i < 200; i++) {	/* Too much? */
1611 			msleep(250);
1612 			write_special_inodes(log, filemap_fdatawrite);
1613 			if (list_empty(&log->cqueue) &&
1614 			    list_empty(&log->synclist))
1615 				break;
1616 		}
1617 	}
1618 	assert(list_empty(&log->cqueue));
1619 
1620 #ifdef CONFIG_JFS_DEBUG
1621 	if (!list_empty(&log->synclist)) {
1622 		struct logsyncblk *lp;
1623 
1624 		printk(KERN_ERR "jfs_flush_journal: synclist not empty\n");
1625 		list_for_each_entry(lp, &log->synclist, synclist) {
1626 			if (lp->xflag & COMMIT_PAGE) {
1627 				struct metapage *mp = (struct metapage *)lp;
1628 				print_hex_dump(KERN_ERR, "metapage: ",
1629 					       DUMP_PREFIX_ADDRESS, 16, 4,
1630 					       mp, sizeof(struct metapage), 0);
1631 				print_hex_dump(KERN_ERR, "page: ",
1632 					       DUMP_PREFIX_ADDRESS, 16,
1633 					       sizeof(long), mp->page,
1634 					       sizeof(struct page), 0);
1635 			} else
1636 				print_hex_dump(KERN_ERR, "tblock:",
1637 					       DUMP_PREFIX_ADDRESS, 16, 4,
1638 					       lp, sizeof(struct tblock), 0);
1639 		}
1640 	}
1641 #else
1642 	WARN_ON(!list_empty(&log->synclist));
1643 #endif
1644 	clear_bit(log_FLUSH, &log->flag);
1645 }
1646 
1647 /*
1648  * NAME:	lmLogShutdown()
1649  *
1650  * FUNCTION:	log shutdown at last LogClose().
1651  *
1652  *		write log syncpt record.
1653  *		update super block to set redone flag to 0.
1654  *
1655  * PARAMETER:	log	- log inode
1656  *
1657  * RETURN:	0	- success
1658  *
1659  * serialization: single last close thread
1660  */
1661 int lmLogShutdown(struct jfs_log * log)
1662 {
1663 	int rc;
1664 	struct lrd lrd;
1665 	int lsn;
1666 	struct logsuper *logsuper;
1667 	struct lbuf *bpsuper;
1668 	struct lbuf *bp;
1669 	struct logpage *lp;
1670 
1671 	jfs_info("lmLogShutdown: log:0x%p", log);
1672 
1673 	jfs_flush_journal(log, 2);
1674 
1675 	/*
1676 	 * write the last SYNCPT record with syncpoint = 0
1677 	 * (i.e., log redo up to HERE !)
1678 	 */
1679 	lrd.logtid = 0;
1680 	lrd.backchain = 0;
1681 	lrd.type = cpu_to_le16(LOG_SYNCPT);
1682 	lrd.length = 0;
1683 	lrd.log.syncpt.sync = 0;
1684 
1685 	lsn = lmWriteRecord(log, NULL, &lrd, NULL);
1686 	bp = log->bp;
1687 	lp = (struct logpage *) bp->l_ldata;
1688 	lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
1689 	lbmWrite(log, log->bp, lbmWRITE | lbmRELEASE | lbmSYNC, 0);
1690 	lbmIOWait(log->bp, lbmFREE);
1691 	log->bp = NULL;
1692 
1693 	/*
1694 	 * synchronous update log superblock
1695 	 * mark log state as shutdown cleanly
1696 	 * (i.e., Log does not need to be replayed).
1697 	 */
1698 	if ((rc = lbmRead(log, 1, &bpsuper)))
1699 		goto out;
1700 
1701 	logsuper = (struct logsuper *) bpsuper->l_ldata;
1702 	logsuper->state = cpu_to_le32(LOGREDONE);
1703 	logsuper->end = cpu_to_le32(lsn);
1704 	lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1705 	rc = lbmIOWait(bpsuper, lbmFREE);
1706 
1707 	jfs_info("lmLogShutdown: lsn:0x%x page:%d eor:%d",
1708 		 lsn, log->page, log->eor);
1709 
1710       out:
1711 	/*
1712 	 * shutdown per log i/o
1713 	 */
1714 	lbmLogShutdown(log);
1715 
1716 	if (rc) {
1717 		jfs_warn("lmLogShutdown: exit(%d)", rc);
1718 	}
1719 	return rc;
1720 }
1721 
1722 
1723 /*
1724  * NAME:	lmLogFileSystem()
1725  *
1726  * FUNCTION:	insert (<activate> = true)/remove (<activate> = false)
1727  *	file system into/from log active file system list.
1728  *
1729  * PARAMETE:	log	- pointer to logs inode.
1730  *		fsdev	- kdev_t of filesystem.
1731  *		serial	- pointer to returned log serial number
1732  *		activate - insert/remove device from active list.
1733  *
1734  * RETURN:	0	- success
1735  *		errors returned by vms_iowait().
1736  */
1737 static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
1738 			   int activate)
1739 {
1740 	int rc = 0;
1741 	int i;
1742 	struct logsuper *logsuper;
1743 	struct lbuf *bpsuper;
1744 	char *uuid = sbi->uuid;
1745 
1746 	/*
1747 	 * insert/remove file system device to log active file system list.
1748 	 */
1749 	if ((rc = lbmRead(log, 1, &bpsuper)))
1750 		return rc;
1751 
1752 	logsuper = (struct logsuper *) bpsuper->l_ldata;
1753 	if (activate) {
1754 		for (i = 0; i < MAX_ACTIVE; i++)
1755 			if (!memcmp(logsuper->active[i].uuid, NULL_UUID, 16)) {
1756 				memcpy(logsuper->active[i].uuid, uuid, 16);
1757 				sbi->aggregate = i;
1758 				break;
1759 			}
1760 		if (i == MAX_ACTIVE) {
1761 			jfs_warn("Too many file systems sharing journal!");
1762 			lbmFree(bpsuper);
1763 			return -EMFILE;	/* Is there a better rc? */
1764 		}
1765 	} else {
1766 		for (i = 0; i < MAX_ACTIVE; i++)
1767 			if (!memcmp(logsuper->active[i].uuid, uuid, 16)) {
1768 				memcpy(logsuper->active[i].uuid, NULL_UUID, 16);
1769 				break;
1770 			}
1771 		if (i == MAX_ACTIVE) {
1772 			jfs_warn("Somebody stomped on the journal!");
1773 			lbmFree(bpsuper);
1774 			return -EIO;
1775 		}
1776 
1777 	}
1778 
1779 	/*
1780 	 * synchronous write log superblock:
1781 	 *
1782 	 * write sidestream bypassing write queue:
1783 	 * at file system mount, log super block is updated for
1784 	 * activation of the file system before any log record
1785 	 * (MOUNT record) of the file system, and at file system
1786 	 * unmount, all meta data for the file system has been
1787 	 * flushed before log super block is updated for deactivation
1788 	 * of the file system.
1789 	 */
1790 	lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1791 	rc = lbmIOWait(bpsuper, lbmFREE);
1792 
1793 	return rc;
1794 }
1795 
1796 /*
1797  *		log buffer manager (lbm)
1798  *		------------------------
1799  *
1800  * special purpose buffer manager supporting log i/o requirements.
1801  *
1802  * per log write queue:
1803  * log pageout occurs in serial order by fifo write queue and
1804  * restricting to a single i/o in pregress at any one time.
1805  * a circular singly-linked list
1806  * (log->wrqueue points to the tail, and buffers are linked via
1807  * bp->wrqueue field), and
1808  * maintains log page in pageout ot waiting for pageout in serial pageout.
1809  */
1810 
1811 /*
1812  *	lbmLogInit()
1813  *
1814  * initialize per log I/O setup at lmLogInit()
1815  */
1816 static int lbmLogInit(struct jfs_log * log)
1817 {				/* log inode */
1818 	int i;
1819 	struct lbuf *lbuf;
1820 
1821 	jfs_info("lbmLogInit: log:0x%p", log);
1822 
1823 	/* initialize current buffer cursor */
1824 	log->bp = NULL;
1825 
1826 	/* initialize log device write queue */
1827 	log->wqueue = NULL;
1828 
1829 	/*
1830 	 * Each log has its own buffer pages allocated to it.  These are
1831 	 * not managed by the page cache.  This ensures that a transaction
1832 	 * writing to the log does not block trying to allocate a page from
1833 	 * the page cache (for the log).  This would be bad, since page
1834 	 * allocation waits on the kswapd thread that may be committing inodes
1835 	 * which would cause log activity.  Was that clear?  I'm trying to
1836 	 * avoid deadlock here.
1837 	 */
1838 	init_waitqueue_head(&log->free_wait);
1839 
1840 	log->lbuf_free = NULL;
1841 
1842 	for (i = 0; i < LOGPAGES;) {
1843 		char *buffer;
1844 		uint offset;
1845 		struct page *page;
1846 
1847 		buffer = (char *) get_zeroed_page(GFP_KERNEL);
1848 		if (buffer == NULL)
1849 			goto error;
1850 		page = virt_to_page(buffer);
1851 		for (offset = 0; offset < PAGE_SIZE; offset += LOGPSIZE) {
1852 			lbuf = kmalloc(sizeof(struct lbuf), GFP_KERNEL);
1853 			if (lbuf == NULL) {
1854 				if (offset == 0)
1855 					free_page((unsigned long) buffer);
1856 				goto error;
1857 			}
1858 			if (offset) /* we already have one reference */
1859 				get_page(page);
1860 			lbuf->l_offset = offset;
1861 			lbuf->l_ldata = buffer + offset;
1862 			lbuf->l_page = page;
1863 			lbuf->l_log = log;
1864 			init_waitqueue_head(&lbuf->l_ioevent);
1865 
1866 			lbuf->l_freelist = log->lbuf_free;
1867 			log->lbuf_free = lbuf;
1868 			i++;
1869 		}
1870 	}
1871 
1872 	return (0);
1873 
1874       error:
1875 	lbmLogShutdown(log);
1876 	return -ENOMEM;
1877 }
1878 
1879 
1880 /*
1881  *	lbmLogShutdown()
1882  *
1883  * finalize per log I/O setup at lmLogShutdown()
1884  */
1885 static void lbmLogShutdown(struct jfs_log * log)
1886 {
1887 	struct lbuf *lbuf;
1888 
1889 	jfs_info("lbmLogShutdown: log:0x%p", log);
1890 
1891 	lbuf = log->lbuf_free;
1892 	while (lbuf) {
1893 		struct lbuf *next = lbuf->l_freelist;
1894 		__free_page(lbuf->l_page);
1895 		kfree(lbuf);
1896 		lbuf = next;
1897 	}
1898 }
1899 
1900 
1901 /*
1902  *	lbmAllocate()
1903  *
1904  * allocate an empty log buffer
1905  */
1906 static struct lbuf *lbmAllocate(struct jfs_log * log, int pn)
1907 {
1908 	struct lbuf *bp;
1909 	unsigned long flags;
1910 
1911 	/*
1912 	 * recycle from log buffer freelist if any
1913 	 */
1914 	LCACHE_LOCK(flags);
1915 	LCACHE_SLEEP_COND(log->free_wait, (bp = log->lbuf_free), flags);
1916 	log->lbuf_free = bp->l_freelist;
1917 	LCACHE_UNLOCK(flags);
1918 
1919 	bp->l_flag = 0;
1920 
1921 	bp->l_wqnext = NULL;
1922 	bp->l_freelist = NULL;
1923 
1924 	bp->l_pn = pn;
1925 	bp->l_blkno = log->base + (pn << (L2LOGPSIZE - log->l2bsize));
1926 	bp->l_ceor = 0;
1927 
1928 	return bp;
1929 }
1930 
1931 
1932 /*
1933  *	lbmFree()
1934  *
1935  * release a log buffer to freelist
1936  */
1937 static void lbmFree(struct lbuf * bp)
1938 {
1939 	unsigned long flags;
1940 
1941 	LCACHE_LOCK(flags);
1942 
1943 	lbmfree(bp);
1944 
1945 	LCACHE_UNLOCK(flags);
1946 }
1947 
1948 static void lbmfree(struct lbuf * bp)
1949 {
1950 	struct jfs_log *log = bp->l_log;
1951 
1952 	assert(bp->l_wqnext == NULL);
1953 
1954 	/*
1955 	 * return the buffer to head of freelist
1956 	 */
1957 	bp->l_freelist = log->lbuf_free;
1958 	log->lbuf_free = bp;
1959 
1960 	wake_up(&log->free_wait);
1961 	return;
1962 }
1963 
1964 
1965 /*
1966  * NAME:	lbmRedrive
1967  *
1968  * FUNCTION:	add a log buffer to the log redrive list
1969  *
1970  * PARAMETER:
1971  *	bp	- log buffer
1972  *
1973  * NOTES:
1974  *	Takes log_redrive_lock.
1975  */
1976 static inline void lbmRedrive(struct lbuf *bp)
1977 {
1978 	unsigned long flags;
1979 
1980 	spin_lock_irqsave(&log_redrive_lock, flags);
1981 	bp->l_redrive_next = log_redrive_list;
1982 	log_redrive_list = bp;
1983 	spin_unlock_irqrestore(&log_redrive_lock, flags);
1984 
1985 	wake_up_process(jfsIOthread);
1986 }
1987 
1988 
1989 /*
1990  *	lbmRead()
1991  */
1992 static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
1993 {
1994 	struct bio *bio;
1995 	struct lbuf *bp;
1996 
1997 	/*
1998 	 * allocate a log buffer
1999 	 */
2000 	*bpp = bp = lbmAllocate(log, pn);
2001 	jfs_info("lbmRead: bp:0x%p pn:0x%x", bp, pn);
2002 
2003 	bp->l_flag |= lbmREAD;
2004 
2005 	bio = bio_alloc(GFP_NOFS, 1);
2006 
2007 	bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
2008 	bio->bi_bdev = log->bdev;
2009 	bio->bi_io_vec[0].bv_page = bp->l_page;
2010 	bio->bi_io_vec[0].bv_len = LOGPSIZE;
2011 	bio->bi_io_vec[0].bv_offset = bp->l_offset;
2012 
2013 	bio->bi_vcnt = 1;
2014 	bio->bi_idx = 0;
2015 	bio->bi_size = LOGPSIZE;
2016 
2017 	bio->bi_end_io = lbmIODone;
2018 	bio->bi_private = bp;
2019 	submit_bio(READ_SYNC, bio);
2020 
2021 	wait_event(bp->l_ioevent, (bp->l_flag != lbmREAD));
2022 
2023 	return 0;
2024 }
2025 
2026 
2027 /*
2028  *	lbmWrite()
2029  *
2030  * buffer at head of pageout queue stays after completion of
2031  * partial-page pageout and redriven by explicit initiation of
2032  * pageout by caller until full-page pageout is completed and
2033  * released.
2034  *
2035  * device driver i/o done redrives pageout of new buffer at
2036  * head of pageout queue when current buffer at head of pageout
2037  * queue is released at the completion of its full-page pageout.
2038  *
2039  * LOGGC_LOCK() serializes lbmWrite() by lmNextPage() and lmGroupCommit().
2040  * LCACHE_LOCK() serializes xflag between lbmWrite() and lbmIODone()
2041  */
2042 static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag,
2043 		     int cant_block)
2044 {
2045 	struct lbuf *tail;
2046 	unsigned long flags;
2047 
2048 	jfs_info("lbmWrite: bp:0x%p flag:0x%x pn:0x%x", bp, flag, bp->l_pn);
2049 
2050 	/* map the logical block address to physical block address */
2051 	bp->l_blkno =
2052 	    log->base + (bp->l_pn << (L2LOGPSIZE - log->l2bsize));
2053 
2054 	LCACHE_LOCK(flags);		/* disable+lock */
2055 
2056 	/*
2057 	 * initialize buffer for device driver
2058 	 */
2059 	bp->l_flag = flag;
2060 
2061 	/*
2062 	 *	insert bp at tail of write queue associated with log
2063 	 *
2064 	 * (request is either for bp already/currently at head of queue
2065 	 * or new bp to be inserted at tail)
2066 	 */
2067 	tail = log->wqueue;
2068 
2069 	/* is buffer not already on write queue ? */
2070 	if (bp->l_wqnext == NULL) {
2071 		/* insert at tail of wqueue */
2072 		if (tail == NULL) {
2073 			log->wqueue = bp;
2074 			bp->l_wqnext = bp;
2075 		} else {
2076 			log->wqueue = bp;
2077 			bp->l_wqnext = tail->l_wqnext;
2078 			tail->l_wqnext = bp;
2079 		}
2080 
2081 		tail = bp;
2082 	}
2083 
2084 	/* is buffer at head of wqueue and for write ? */
2085 	if ((bp != tail->l_wqnext) || !(flag & lbmWRITE)) {
2086 		LCACHE_UNLOCK(flags);	/* unlock+enable */
2087 		return;
2088 	}
2089 
2090 	LCACHE_UNLOCK(flags);	/* unlock+enable */
2091 
2092 	if (cant_block)
2093 		lbmRedrive(bp);
2094 	else if (flag & lbmSYNC)
2095 		lbmStartIO(bp);
2096 	else {
2097 		LOGGC_UNLOCK(log);
2098 		lbmStartIO(bp);
2099 		LOGGC_LOCK(log);
2100 	}
2101 }
2102 
2103 
2104 /*
2105  *	lbmDirectWrite()
2106  *
2107  * initiate pageout bypassing write queue for sidestream
2108  * (e.g., log superblock) write;
2109  */
2110 static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag)
2111 {
2112 	jfs_info("lbmDirectWrite: bp:0x%p flag:0x%x pn:0x%x",
2113 		 bp, flag, bp->l_pn);
2114 
2115 	/*
2116 	 * initialize buffer for device driver
2117 	 */
2118 	bp->l_flag = flag | lbmDIRECT;
2119 
2120 	/* map the logical block address to physical block address */
2121 	bp->l_blkno =
2122 	    log->base + (bp->l_pn << (L2LOGPSIZE - log->l2bsize));
2123 
2124 	/*
2125 	 *	initiate pageout of the page
2126 	 */
2127 	lbmStartIO(bp);
2128 }
2129 
2130 
2131 /*
2132  * NAME:	lbmStartIO()
2133  *
2134  * FUNCTION:	Interface to DD strategy routine
2135  *
2136  * RETURN:	none
2137  *
2138  * serialization: LCACHE_LOCK() is NOT held during log i/o;
2139  */
2140 static void lbmStartIO(struct lbuf * bp)
2141 {
2142 	struct bio *bio;
2143 	struct jfs_log *log = bp->l_log;
2144 
2145 	jfs_info("lbmStartIO\n");
2146 
2147 	bio = bio_alloc(GFP_NOFS, 1);
2148 	bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
2149 	bio->bi_bdev = log->bdev;
2150 	bio->bi_io_vec[0].bv_page = bp->l_page;
2151 	bio->bi_io_vec[0].bv_len = LOGPSIZE;
2152 	bio->bi_io_vec[0].bv_offset = bp->l_offset;
2153 
2154 	bio->bi_vcnt = 1;
2155 	bio->bi_idx = 0;
2156 	bio->bi_size = LOGPSIZE;
2157 
2158 	bio->bi_end_io = lbmIODone;
2159 	bio->bi_private = bp;
2160 
2161 	/* check if journaling to disk has been disabled */
2162 	if (log->no_integrity) {
2163 		bio->bi_size = 0;
2164 		lbmIODone(bio, 0);
2165 	} else {
2166 		submit_bio(WRITE_SYNC, bio);
2167 		INCREMENT(lmStat.submitted);
2168 	}
2169 }
2170 
2171 
2172 /*
2173  *	lbmIOWait()
2174  */
2175 static int lbmIOWait(struct lbuf * bp, int flag)
2176 {
2177 	unsigned long flags;
2178 	int rc = 0;
2179 
2180 	jfs_info("lbmIOWait1: bp:0x%p flag:0x%x:0x%x", bp, bp->l_flag, flag);
2181 
2182 	LCACHE_LOCK(flags);		/* disable+lock */
2183 
2184 	LCACHE_SLEEP_COND(bp->l_ioevent, (bp->l_flag & lbmDONE), flags);
2185 
2186 	rc = (bp->l_flag & lbmERROR) ? -EIO : 0;
2187 
2188 	if (flag & lbmFREE)
2189 		lbmfree(bp);
2190 
2191 	LCACHE_UNLOCK(flags);	/* unlock+enable */
2192 
2193 	jfs_info("lbmIOWait2: bp:0x%p flag:0x%x:0x%x", bp, bp->l_flag, flag);
2194 	return rc;
2195 }
2196 
2197 /*
2198  *	lbmIODone()
2199  *
2200  * executed at INTIODONE level
2201  */
2202 static void lbmIODone(struct bio *bio, int error)
2203 {
2204 	struct lbuf *bp = bio->bi_private;
2205 	struct lbuf *nextbp, *tail;
2206 	struct jfs_log *log;
2207 	unsigned long flags;
2208 
2209 	/*
2210 	 * get back jfs buffer bound to the i/o buffer
2211 	 */
2212 	jfs_info("lbmIODone: bp:0x%p flag:0x%x", bp, bp->l_flag);
2213 
2214 	LCACHE_LOCK(flags);		/* disable+lock */
2215 
2216 	bp->l_flag |= lbmDONE;
2217 
2218 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
2219 		bp->l_flag |= lbmERROR;
2220 
2221 		jfs_err("lbmIODone: I/O error in JFS log");
2222 	}
2223 
2224 	bio_put(bio);
2225 
2226 	/*
2227 	 *	pagein completion
2228 	 */
2229 	if (bp->l_flag & lbmREAD) {
2230 		bp->l_flag &= ~lbmREAD;
2231 
2232 		LCACHE_UNLOCK(flags);	/* unlock+enable */
2233 
2234 		/* wakeup I/O initiator */
2235 		LCACHE_WAKEUP(&bp->l_ioevent);
2236 
2237 		return;
2238 	}
2239 
2240 	/*
2241 	 *	pageout completion
2242 	 *
2243 	 * the bp at the head of write queue has completed pageout.
2244 	 *
2245 	 * if single-commit/full-page pageout, remove the current buffer
2246 	 * from head of pageout queue, and redrive pageout with
2247 	 * the new buffer at head of pageout queue;
2248 	 * otherwise, the partial-page pageout buffer stays at
2249 	 * the head of pageout queue to be redriven for pageout
2250 	 * by lmGroupCommit() until full-page pageout is completed.
2251 	 */
2252 	bp->l_flag &= ~lbmWRITE;
2253 	INCREMENT(lmStat.pagedone);
2254 
2255 	/* update committed lsn */
2256 	log = bp->l_log;
2257 	log->clsn = (bp->l_pn << L2LOGPSIZE) + bp->l_ceor;
2258 
2259 	if (bp->l_flag & lbmDIRECT) {
2260 		LCACHE_WAKEUP(&bp->l_ioevent);
2261 		LCACHE_UNLOCK(flags);
2262 		return;
2263 	}
2264 
2265 	tail = log->wqueue;
2266 
2267 	/* single element queue */
2268 	if (bp == tail) {
2269 		/* remove head buffer of full-page pageout
2270 		 * from log device write queue
2271 		 */
2272 		if (bp->l_flag & lbmRELEASE) {
2273 			log->wqueue = NULL;
2274 			bp->l_wqnext = NULL;
2275 		}
2276 	}
2277 	/* multi element queue */
2278 	else {
2279 		/* remove head buffer of full-page pageout
2280 		 * from log device write queue
2281 		 */
2282 		if (bp->l_flag & lbmRELEASE) {
2283 			nextbp = tail->l_wqnext = bp->l_wqnext;
2284 			bp->l_wqnext = NULL;
2285 
2286 			/*
2287 			 * redrive pageout of next page at head of write queue:
2288 			 * redrive next page without any bound tblk
2289 			 * (i.e., page w/o any COMMIT records), or
2290 			 * first page of new group commit which has been
2291 			 * queued after current page (subsequent pageout
2292 			 * is performed synchronously, except page without
2293 			 * any COMMITs) by lmGroupCommit() as indicated
2294 			 * by lbmWRITE flag;
2295 			 */
2296 			if (nextbp->l_flag & lbmWRITE) {
2297 				/*
2298 				 * We can't do the I/O at interrupt time.
2299 				 * The jfsIO thread can do it
2300 				 */
2301 				lbmRedrive(nextbp);
2302 			}
2303 		}
2304 	}
2305 
2306 	/*
2307 	 *	synchronous pageout:
2308 	 *
2309 	 * buffer has not necessarily been removed from write queue
2310 	 * (e.g., synchronous write of partial-page with COMMIT):
2311 	 * leave buffer for i/o initiator to dispose
2312 	 */
2313 	if (bp->l_flag & lbmSYNC) {
2314 		LCACHE_UNLOCK(flags);	/* unlock+enable */
2315 
2316 		/* wakeup I/O initiator */
2317 		LCACHE_WAKEUP(&bp->l_ioevent);
2318 	}
2319 
2320 	/*
2321 	 *	Group Commit pageout:
2322 	 */
2323 	else if (bp->l_flag & lbmGC) {
2324 		LCACHE_UNLOCK(flags);
2325 		lmPostGC(bp);
2326 	}
2327 
2328 	/*
2329 	 *	asynchronous pageout:
2330 	 *
2331 	 * buffer must have been removed from write queue:
2332 	 * insert buffer at head of freelist where it can be recycled
2333 	 */
2334 	else {
2335 		assert(bp->l_flag & lbmRELEASE);
2336 		assert(bp->l_flag & lbmFREE);
2337 		lbmfree(bp);
2338 
2339 		LCACHE_UNLOCK(flags);	/* unlock+enable */
2340 	}
2341 }
2342 
2343 int jfsIOWait(void *arg)
2344 {
2345 	struct lbuf *bp;
2346 
2347 	do {
2348 		spin_lock_irq(&log_redrive_lock);
2349 		while ((bp = log_redrive_list)) {
2350 			log_redrive_list = bp->l_redrive_next;
2351 			bp->l_redrive_next = NULL;
2352 			spin_unlock_irq(&log_redrive_lock);
2353 			lbmStartIO(bp);
2354 			spin_lock_irq(&log_redrive_lock);
2355 		}
2356 
2357 		if (freezing(current)) {
2358 			spin_unlock_irq(&log_redrive_lock);
2359 			refrigerator();
2360 		} else {
2361 			set_current_state(TASK_INTERRUPTIBLE);
2362 			spin_unlock_irq(&log_redrive_lock);
2363 			schedule();
2364 			__set_current_state(TASK_RUNNING);
2365 		}
2366 	} while (!kthread_should_stop());
2367 
2368 	jfs_info("jfsIOWait being killed!");
2369 	return 0;
2370 }
2371 
2372 /*
2373  * NAME:	lmLogFormat()/jfs_logform()
2374  *
2375  * FUNCTION:	format file system log
2376  *
2377  * PARAMETERS:
2378  *	log	- volume log
2379  *	logAddress - start address of log space in FS block
2380  *	logSize	- length of log space in FS block;
2381  *
2382  * RETURN:	0	- success
2383  *		-EIO	- i/o error
2384  *
2385  * XXX: We're synchronously writing one page at a time.  This needs to
2386  *	be improved by writing multiple pages at once.
2387  */
2388 int lmLogFormat(struct jfs_log *log, s64 logAddress, int logSize)
2389 {
2390 	int rc = -EIO;
2391 	struct jfs_sb_info *sbi;
2392 	struct logsuper *logsuper;
2393 	struct logpage *lp;
2394 	int lspn;		/* log sequence page number */
2395 	struct lrd *lrd_ptr;
2396 	int npages = 0;
2397 	struct lbuf *bp;
2398 
2399 	jfs_info("lmLogFormat: logAddress:%Ld logSize:%d",
2400 		 (long long)logAddress, logSize);
2401 
2402 	sbi = list_entry(log->sb_list.next, struct jfs_sb_info, log_list);
2403 
2404 	/* allocate a log buffer */
2405 	bp = lbmAllocate(log, 1);
2406 
2407 	npages = logSize >> sbi->l2nbperpage;
2408 
2409 	/*
2410 	 *	log space:
2411 	 *
2412 	 * page 0 - reserved;
2413 	 * page 1 - log superblock;
2414 	 * page 2 - log data page: A SYNC log record is written
2415 	 *	    into this page at logform time;
2416 	 * pages 3-N - log data page: set to empty log data pages;
2417 	 */
2418 	/*
2419 	 *	init log superblock: log page 1
2420 	 */
2421 	logsuper = (struct logsuper *) bp->l_ldata;
2422 
2423 	logsuper->magic = cpu_to_le32(LOGMAGIC);
2424 	logsuper->version = cpu_to_le32(LOGVERSION);
2425 	logsuper->state = cpu_to_le32(LOGREDONE);
2426 	logsuper->flag = cpu_to_le32(sbi->mntflag);	/* ? */
2427 	logsuper->size = cpu_to_le32(npages);
2428 	logsuper->bsize = cpu_to_le32(sbi->bsize);
2429 	logsuper->l2bsize = cpu_to_le32(sbi->l2bsize);
2430 	logsuper->end = cpu_to_le32(2 * LOGPSIZE + LOGPHDRSIZE + LOGRDSIZE);
2431 
2432 	bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2433 	bp->l_blkno = logAddress + sbi->nbperpage;
2434 	lbmStartIO(bp);
2435 	if ((rc = lbmIOWait(bp, 0)))
2436 		goto exit;
2437 
2438 	/*
2439 	 *	init pages 2 to npages-1 as log data pages:
2440 	 *
2441 	 * log page sequence number (lpsn) initialization:
2442 	 *
2443 	 * pn:   0     1     2     3                 n-1
2444 	 *       +-----+-----+=====+=====+===.....===+=====+
2445 	 * lspn:             N-1   0     1           N-2
2446 	 *                   <--- N page circular file ---->
2447 	 *
2448 	 * the N (= npages-2) data pages of the log is maintained as
2449 	 * a circular file for the log records;
2450 	 * lpsn grows by 1 monotonically as each log page is written
2451 	 * to the circular file of the log;
2452 	 * and setLogpage() will not reset the page number even if
2453 	 * the eor is equal to LOGPHDRSIZE. In order for binary search
2454 	 * still work in find log end process, we have to simulate the
2455 	 * log wrap situation at the log format time.
2456 	 * The 1st log page written will have the highest lpsn. Then
2457 	 * the succeeding log pages will have ascending order of
2458 	 * the lspn starting from 0, ... (N-2)
2459 	 */
2460 	lp = (struct logpage *) bp->l_ldata;
2461 	/*
2462 	 * initialize 1st log page to be written: lpsn = N - 1,
2463 	 * write a SYNCPT log record is written to this page
2464 	 */
2465 	lp->h.page = lp->t.page = cpu_to_le32(npages - 3);
2466 	lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE + LOGRDSIZE);
2467 
2468 	lrd_ptr = (struct lrd *) &lp->data;
2469 	lrd_ptr->logtid = 0;
2470 	lrd_ptr->backchain = 0;
2471 	lrd_ptr->type = cpu_to_le16(LOG_SYNCPT);
2472 	lrd_ptr->length = 0;
2473 	lrd_ptr->log.syncpt.sync = 0;
2474 
2475 	bp->l_blkno += sbi->nbperpage;
2476 	bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2477 	lbmStartIO(bp);
2478 	if ((rc = lbmIOWait(bp, 0)))
2479 		goto exit;
2480 
2481 	/*
2482 	 *	initialize succeeding log pages: lpsn = 0, 1, ..., (N-2)
2483 	 */
2484 	for (lspn = 0; lspn < npages - 3; lspn++) {
2485 		lp->h.page = lp->t.page = cpu_to_le32(lspn);
2486 		lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
2487 
2488 		bp->l_blkno += sbi->nbperpage;
2489 		bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2490 		lbmStartIO(bp);
2491 		if ((rc = lbmIOWait(bp, 0)))
2492 			goto exit;
2493 	}
2494 
2495 	rc = 0;
2496 exit:
2497 	/*
2498 	 *	finalize log
2499 	 */
2500 	/* release the buffer */
2501 	lbmFree(bp);
2502 
2503 	return rc;
2504 }
2505 
2506 #ifdef CONFIG_JFS_STATISTICS
2507 static int jfs_lmstats_proc_show(struct seq_file *m, void *v)
2508 {
2509 	seq_printf(m,
2510 		       "JFS Logmgr stats\n"
2511 		       "================\n"
2512 		       "commits = %d\n"
2513 		       "writes submitted = %d\n"
2514 		       "writes completed = %d\n"
2515 		       "full pages submitted = %d\n"
2516 		       "partial pages submitted = %d\n",
2517 		       lmStat.commit,
2518 		       lmStat.submitted,
2519 		       lmStat.pagedone,
2520 		       lmStat.full_page,
2521 		       lmStat.partial_page);
2522 	return 0;
2523 }
2524 
2525 static int jfs_lmstats_proc_open(struct inode *inode, struct file *file)
2526 {
2527 	return single_open(file, jfs_lmstats_proc_show, NULL);
2528 }
2529 
2530 const struct file_operations jfs_lmstats_proc_fops = {
2531 	.owner		= THIS_MODULE,
2532 	.open		= jfs_lmstats_proc_open,
2533 	.read		= seq_read,
2534 	.llseek		= seq_lseek,
2535 	.release	= single_release,
2536 };
2537 #endif /* CONFIG_JFS_STATISTICS */
2538