jfs_logmgr.c

linux 内核源代码

	nextbp = lbmAllocate(log, log->page);
	nextbp->l_eor = log->eor;
	log->bp = nextbp;

	/* initialize next log page */
	lp = (struct logpage *) nextbp->l_ldata;
	lp->h.page = lp->t.page = cpu_to_le32(lspn + 1);
	lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);

	return 0;
}


/*
 * NAME:	lmGroupCommit()
 *
 * FUNCTION:	group commit
 *	initiate pageout of the pages with COMMIT in the order of
 *	page number - redrive pageout of the page at the head of
 *	pageout queue until full page has been written.
 *
 * RETURN:
 *
 * NOTE:
 *	LOGGC_LOCK serializes log group commit queue, and
 *	transaction blocks on the commit queue.
 *	N.B. LOG_LOCK is NOT held during lmGroupCommit().
 */
int lmGroupCommit(struct jfs_log * log, struct tblock * tblk)
{
	int rc = 0;

	LOGGC_LOCK(log);

	/* group committed already ? */
	if (tblk->flag & tblkGC_COMMITTED) {
		if (tblk->flag & tblkGC_ERROR)
			rc = -EIO;

		LOGGC_UNLOCK(log);
		return rc;
	}
	jfs_info("lmGroup Commit: tblk = 0x%p, gcrtc = %d", tblk, log->gcrtc);

	if (tblk->xflag & COMMIT_LAZY)
		tblk->flag |= tblkGC_LAZY;

	if ((!(log->cflag & logGC_PAGEOUT)) && (!list_empty(&log->cqueue)) &&
	    (!(tblk->xflag & COMMIT_LAZY) || test_bit(log_FLUSH, &log->flag)
	     || jfs_tlocks_low)) {
		/*
		 * No pageout in progress
		 *
		 * start group commit as its group leader.
		 */
		log->cflag |= logGC_PAGEOUT;

		lmGCwrite(log, 0);
	}

	if (tblk->xflag & COMMIT_LAZY) {
		/*
		 * Lazy transactions can leave now
		 */
		LOGGC_UNLOCK(log);
		return 0;
	}

	/* lmGCwrite gives up LOGGC_LOCK, check again */

	if (tblk->flag & tblkGC_COMMITTED) {
		if (tblk->flag & tblkGC_ERROR)
			rc = -EIO;

		LOGGC_UNLOCK(log);
		return rc;
	}

	/* upcount transaction waiting for completion
	 */
	log->gcrtc++;
	tblk->flag |= tblkGC_READY;

	__SLEEP_COND(tblk->gcwait, (tblk->flag & tblkGC_COMMITTED),
		     LOGGC_LOCK(log), LOGGC_UNLOCK(log));

	/* removed from commit queue */
	if (tblk->flag & tblkGC_ERROR)
		rc = -EIO;

	LOGGC_UNLOCK(log);
	return rc;
}

/*
 * NAME:	lmGCwrite()
 *
 * FUNCTION:	group commit write
 *	initiate write of log page, building a group of all transactions
 *	with commit records on that page.
 *
 * RETURN:	None
 *
 * NOTE:
 *	LOGGC_LOCK must be held by caller.
 *	N.B. LOG_LOCK is NOT held during lmGroupCommit().
 */
static void lmGCwrite(struct jfs_log * log, int cant_write)
{
	struct lbuf *bp;
	struct logpage *lp;
	int gcpn;		/* group commit page number */
	struct tblock *tblk;
	struct tblock *xtblk = NULL;

	/*
	 * build the commit group of a log page
	 *
	 * scan commit queue and make a commit group of all
	 * transactions with COMMIT records on the same log page.
	 */
	/* get the head tblk on the commit queue */
	gcpn = list_entry(log->cqueue.next, struct tblock, cqueue)->pn;

	list_for_each_entry(tblk, &log->cqueue, cqueue) {
		if (tblk->pn != gcpn)
			break;

		xtblk = tblk;

		/* state transition: (QUEUE, READY) -> COMMIT */
		tblk->flag |= tblkGC_COMMIT;
	}
	tblk = xtblk;		/* last tblk of the page */

	/*
	 * pageout to commit transactions on the log page.
	 */
	bp = (struct lbuf *) tblk->bp;
	lp = (struct logpage *) bp->l_ldata;
	/* is page already full ? */
	if (tblk->flag & tblkGC_EOP) {
		/* mark page to free at end of group commit of the page */
		tblk->flag &= ~tblkGC_EOP;
		tblk->flag |= tblkGC_FREE;
		bp->l_ceor = bp->l_eor;
		lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
		lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmGC,
			 cant_write);
		INCREMENT(lmStat.full_page);
	}
	/* page is not yet full */
	else {
		bp->l_ceor = tblk->eor;	/* ? bp->l_ceor = bp->l_eor; */
		lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
		lbmWrite(log, bp, lbmWRITE | lbmGC, cant_write);
		INCREMENT(lmStat.partial_page);
	}
}

/*
 * NAME:	lmPostGC()
 *
 * FUNCTION:	group commit post-processing
 *	Processes transactions after their commit records have been written
 *	to disk, redriving log I/O if necessary.
 *
 * RETURN:	None
 *
 * NOTE:
 *	This routine is called a interrupt time by lbmIODone
 */
static void lmPostGC(struct lbuf * bp)
{
	unsigned long flags;
	struct jfs_log *log = bp->l_log;
	struct logpage *lp;
	struct tblock *tblk, *temp;

	//LOGGC_LOCK(log);
	spin_lock_irqsave(&log->gclock, flags);
	/*
	 * current pageout of group commit completed.
	 *
	 * remove/wakeup transactions from commit queue who were
	 * group committed with the current log page
	 */
	list_for_each_entry_safe(tblk, temp, &log->cqueue, cqueue) {
		if (!(tblk->flag & tblkGC_COMMIT))
			break;
		/* if transaction was marked GC_COMMIT then
		 * it has been shipped in the current pageout
		 * and made it to disk - it is committed.
		 */

		if (bp->l_flag & lbmERROR)
			tblk->flag |= tblkGC_ERROR;

		/* remove it from the commit queue */
		list_del(&tblk->cqueue);
		tblk->flag &= ~tblkGC_QUEUE;

		if (tblk == log->flush_tblk) {
			/* we can stop flushing the log now */
			clear_bit(log_FLUSH, &log->flag);
			log->flush_tblk = NULL;
		}

		jfs_info("lmPostGC: tblk = 0x%p, flag = 0x%x", tblk,
			 tblk->flag);

		if (!(tblk->xflag & COMMIT_FORCE))
			/*
			 * Hand tblk over to lazy commit thread
			 */
			txLazyUnlock(tblk);
		else {
			/* state transition: COMMIT -> COMMITTED */
			tblk->flag |= tblkGC_COMMITTED;

			if (tblk->flag & tblkGC_READY)
				log->gcrtc--;

			LOGGC_WAKEUP(tblk);
		}

		/* was page full before pageout ?
		 * (and this is the last tblk bound with the page)
		 */
		if (tblk->flag & tblkGC_FREE)
			lbmFree(bp);
		/* did page become full after pageout ?
		 * (and this is the last tblk bound with the page)
		 */
		else if (tblk->flag & tblkGC_EOP) {
			/* finalize the page */
			lp = (struct logpage *) bp->l_ldata;
			bp->l_ceor = bp->l_eor;
			lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
			jfs_info("lmPostGC: calling lbmWrite");
			lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE,
				 1);
		}

	}

	/* are there any transactions who have entered lnGroupCommit()
	 * (whose COMMITs are after that of the last log page written.
	 * They are waiting for new group commit (above at (SLEEP 1))
	 * or lazy transactions are on a full (queued) log page,
	 * select the latest ready transaction as new group leader and
	 * wake her up to lead her group.
	 */
	if ((!list_empty(&log->cqueue)) &&
	    ((log->gcrtc > 0) || (tblk->bp->l_wqnext != NULL) ||
	     test_bit(log_FLUSH, &log->flag) || jfs_tlocks_low))
		/*
		 * Call lmGCwrite with new group leader
		 */
		lmGCwrite(log, 1);

	/* no transaction are ready yet (transactions are only just
	 * queued (GC_QUEUE) and not entered for group commit yet).
	 * the first transaction entering group commit
	 * will elect herself as new group leader.
	 */
	else
		log->cflag &= ~logGC_PAGEOUT;

	//LOGGC_UNLOCK(log);
	spin_unlock_irqrestore(&log->gclock, flags);
	return;
}

/*
 * NAME:	lmLogSync()
 *
 * FUNCTION:	write log SYNCPT record for specified log
 *	if new sync address is available
 *	(normally the case if sync() is executed by back-ground
 *	process).
 *	calculate new value of i_nextsync which determines when
 *	this code is called again.
 *
 * PARAMETERS:	log	- log structure
 *		hard_sync - 1 to force all metadata to be written
 *
 * RETURN:	0
 *
 * serialization: LOG_LOCK() held on entry/exit
 */
static int lmLogSync(struct jfs_log * log, int hard_sync)
{
	int logsize;
	int written;		/* written since last syncpt */
	int free;		/* free space left available */
	int delta;		/* additional delta to write normally */
	int more;		/* additional write granted */
	struct lrd lrd;
	int lsn;
	struct logsyncblk *lp;
	struct jfs_sb_info *sbi;
	unsigned long flags;

	/* push dirty metapages out to disk */
	if (hard_sync)
		list_for_each_entry(sbi, &log->sb_list, log_list) {
			filemap_fdatawrite(sbi->ipbmap->i_mapping);
			filemap_fdatawrite(sbi->ipimap->i_mapping);
			filemap_fdatawrite(sbi->direct_inode->i_mapping);
		}
	else
		list_for_each_entry(sbi, &log->sb_list, log_list) {
			filemap_flush(sbi->ipbmap->i_mapping);
			filemap_flush(sbi->ipimap->i_mapping);
			filemap_flush(sbi->direct_inode->i_mapping);
		}

	/*
	 *	forward syncpt
	 */
	/* if last sync is same as last syncpt,
	 * invoke sync point forward processing to update sync.
	 */

	if (log->sync == log->syncpt) {
		LOGSYNC_LOCK(log, flags);
		if (list_empty(&log->synclist))
			log->sync = log->lsn;
		else {
			lp = list_entry(log->synclist.next,
					struct logsyncblk, synclist);
			log->sync = lp->lsn;
		}
		LOGSYNC_UNLOCK(log, flags);

	}

	/* if sync is different from last syncpt,
	 * write a SYNCPT record with syncpt = sync.
	 * reset syncpt = sync
	 */
	if (log->sync != log->syncpt) {
		lrd.logtid = 0;
		lrd.backchain = 0;
		lrd.type = cpu_to_le16(LOG_SYNCPT);
		lrd.length = 0;
		lrd.log.syncpt.sync = cpu_to_le32(log->sync);
		lsn = lmWriteRecord(log, NULL, &lrd, NULL);

		log->syncpt = log->sync;
	} else
		lsn = log->lsn;

	/*
	 *	setup next syncpt trigger (SWAG)
	 */
	logsize = log->logsize;

	logdiff(written, lsn, log);
	free = logsize - written;
	delta = LOGSYNC_DELTA(logsize);
	more = min(free / 2, delta);
	if (more < 2 * LOGPSIZE) {
		jfs_warn("\n ... Log Wrap ... Log Wrap ... Log Wrap ...\n");
		/*
		 *	log wrapping
		 *
		 * option 1 - panic ? No.!
		 * option 2 - shutdown file systems
		 *	      associated with log ?
		 * option 3 - extend log ?
		 */
		/*
		 * option 4 - second chance
		 *
		 * mark log wrapped, and continue.
		 * when all active transactions are completed,
		 * mark log vaild for recovery.
		 * if crashed during invalid state, log state
		 * implies invald log, forcing fsck().
		 */
		/* mark log state log wrap in log superblock */
		/* log->state = LOGWRAP; */

		/* reset sync point computation */
		log->syncpt = log->sync = lsn;
		log->nextsync = delta;
	} else
		/* next syncpt trigger = written + more */
		log->nextsync = written + more;

	/* if number of bytes written from last sync point is more
	 * than 1/4 of the log size, stop new transactions from
	 * starting until all current transactions are completed
	 * by setting syncbarrier flag.
	 */
	if (!test_bit(log_SYNCBARRIER, &log->flag) &&
	    (written > LOGSYNC_BARRIER(logsize)) && log->active) {
		set_bit(log_SYNCBARRIER, &log->flag);
		jfs_info("log barrier on: lsn=0x%x syncpt=0x%x", lsn,
			 log->syncpt);
		/*
		 * We may have to initiate group commit
		 */
		jfs_flush_journal(log, 0);
	}

	return lsn;
}

/*
 * NAME:	jfs_syncpt
 *
 * FUNCTION:	write log SYNCPT record for specified log
 *
 * PARAMETERS:	log	  - log structure
 *		hard_sync - set to 1 to force metadata to be written
 */
void jfs_syncpt(struct jfs_log *log, int hard_sync)
{	LOG_LOCK(log);
	lmLogSync(log, hard_sync);
	LOG_UNLOCK(log);
}

/*
 * NAME:	lmLogOpen()
 *
 * FUNCTION:	open the log on first open;
 *	insert filesystem in the active list of the log.
 *
 * PARAMETER:	ipmnt	- file system mount inode
 *		iplog	- log inode (out)
 *
 * RETURN:
 *
 * serialization:
 */
int lmLogOpen(struct super_block *sb)
{
	int rc;
	struct block_device *bdev;
	struct jfs_log *log;
	struct jfs_sb_info *sbi = JFS_SBI(sb);

	if (sbi->flag & JFS_NOINTEGRITY)
		return open_dummy_log(sb);

	if (sbi->mntflag & JFS_INLINELOG)
		return open_inline_log(sb);

	mutex_lock(&jfs_log_mutex);
	list_for_each_entry(log, &jfs_external_logs, journal_list) {
		if (log->bdev->bd_dev == sbi->logdev) {
			if (memcmp(log->uuid, sbi->loguuid,
				   sizeof(log->uuid))) {
				jfs_warn("wrong uuid on JFS journal\n");
				mutex_unlock(&jfs_log_mutex);
				return -EINVAL;
			}
			/*
			 * add file system to log active file system list
			 */
			if ((rc = lmLogFileSystem(log, sbi, 1))) {
				mutex_unlock(&jfs_log_mutex);
				return rc;
			}
			goto journal_found;
		}
	}

	if (!(log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL))) {
		mutex_unlock(&jfs_log_mutex);
		return -ENOMEM;
	}
	INIT_LIST_HEAD(&log->sb_list);
	init_waitqueue_head(&log->syncwait);

	/*
	 *	external log as separate logical volume
	 *
	 * file systems to log may have n-to-1 relationship;
	 */

	bdev = open_by_devnum(sbi->logdev, FMODE_READ|FMODE_WRITE);
	if (IS_ERR(bdev)) {
		rc = -PTR_ERR(bdev);
		goto free;
	}

	if ((rc = bd_claim(bdev, log))) {
		goto close;
	}

	log->bdev = bdev;
	memcpy(log->uuid, sbi->loguuid, sizeof(log->uuid));

	/*
	 * initialize log:
	 */
	if ((rc = lmLogInit(log)))
		goto unclaim;

	list_add(&log->journal_list, &jfs_external_logs);

	/*
	 * add file system to log active file system list
	 */
	if ((rc = lmLogFileSystem(log, sbi, 1)))
		goto shutdown;

journal_found:
	LOG_LOCK(log);
	list_add(&sbi->log_list, &log->sb_list);
	sbi->log = log;
	LOG_UNLOCK(log);

	mutex_unlock(&jfs_log_mutex);
	return 0;

	/*
	 *	unwind on error
	 */
      shutdown:		/* unwind lbmLogInit() */
	list_del(&log->journal_list);
	lbmLogShutdown(log);

      unclaim:
	bd_release(bdev);

      close:		/* close external log device */
	blkdev_put(bdev);

      free:		/* free log descriptor */
	mutex_unlock(&jfs_log_mutex);
	kfree(log);

	jfs_warn("lmLogOpen: exit(%d)", rc);
	return rc;
}

static int open_inline_log(struct super_block *sb)
{
	struct jfs_log *log;
	int rc;

	if (!(log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL)))
		return -ENOMEM;
	INIT_LIST_HEAD(&log->sb_list);
	init_waitqueue_head(&log->syncwait);

	set_bit(log_INLINELOG, &log->flag);
	log->bdev = sb->s_bdev;
	log->base = addressPXD(&JFS_SBI(sb)->logpxd);
	log->size = lengthPXD(&JFS_SBI(sb)->logpxd) >>
	    (L2LOGPSIZE - sb->s_blocksize_bits);
	log->l2bsize = sb->s_blocksize_bits;
	ASSERT(L2LOGPSIZE >= sb->s_blocksize_bits);

	/*
	 * initialize log.
	 */
	if ((rc = lmLogInit(log))) {
		kfree(log);
		jfs_warn("lmLogOpen: exit(%d)", rc);
		return rc;
	}

	list_add(&JFS_SBI(sb)->log_list, &log->sb_list);
	JFS_SBI(sb)->log = log;

	return rc;
}

static int open_dummy_log(struct super_block *sb)
{
	int rc;

	mutex_lock(&jfs_log_mutex);
	if (!dummy_log) {
		dummy_log = kzalloc(sizeof(struct jfs_log), GFP_KERNEL);
		if (!dummy_log) {
			mutex_unlock(&jfs_log_mutex);
			return -ENOMEM;
		}
		INIT_LIST_HEAD(&dummy_log->sb_list);
		init_waitqueue_head(&dummy_log->syncwait);
		dummy_log->no_integrity = 1;
		/* Make up some stuff */
		dummy_log->base = 0;
		dummy_log->size = 1024;
		rc = lmLogInit(dummy_log);
		if (rc) {
			kfree(dummy_log);
			dummy_log = NULL;
			mutex_unlock(&jfs_log_mutex);
			return rc;
		}
	}

	LOG_LOCK(dummy_log);
	list_add(&JFS_SBI(sb)->log_list, &dummy_log->sb_list);
	JFS_SBI(sb)->log = dummy_log;
	LOG_UNLOCK(dummy_log);
	mutex_unlock(&jfs_log_mutex);

	return 0;
}

/*
 * NAME:	lmLogInit()
 *
 * FUNCTION:	log initialization at first log open.
 *
 *	logredo() (or logformat()) should have been run previously.
 *	initialize the log from log superblock.
 *	set the log state in the superblock to LOGMOUNT and
 *	write SYNCPT log record.
 *
 * PARAMETER:	log	- log structure
 *
 * RETURN:	0	- if ok
 *		-EINVAL	- bad log magic number or superblock dirty
 *		error returned from logwait()
 *
 * serialization: single first open thread
 */
int lmLogInit(struct jfs_log * log)
{
	int rc = 0;
	struct lrd lrd;
	struct logsuper *logsuper;
	struct lbuf *bpsuper;
	struct lbuf *bp;
	struct logpage *lp;
	int lsn = 0;