[PATCH] JFS: Write journal sync points more often

This patch adds jfs_syncpt, which calls lmLogSync to write sync points
to the journal both in jfs_sync_fs and when sync barrier processing
completes.

lmLogSync accomplishes two things:  1) it pushes logged-but-dirty
metadata pages to disk, and 2) it writes a sync record to the journal
so that jfs_fsck doesn't need to replay more transactions than is
necessary.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/jfs/jfs_logmgr.c

@@ -927,9 +927,8 @@ static void lmPostGC(struct lbuf * bp)
  *	calculate new value of i_nextsync which determines when
  *	this code is called again.
  *
- *	this is called only from lmLog().
- *
- * PARAMETER:	ip	- pointer to logs inode.
+ * PARAMETERS:	log	- log structure
+ * 		nosyncwait - 1 if called asynchronously
  *
  * RETURN:	0
  *			
@@ -1051,6 +1050,18 @@ static int lmLogSync(struct jfs_log * log, int nosyncwait)
 	return lsn;
 }
 
+/*
+ * NAME:	jfs_syncpt
+ *
+ * FUNCTION:	write log SYNCPT record for specified log
+ *
+ * PARAMETERS:	log	- log structure
+ */
+void jfs_syncpt(struct jfs_log *log)
+{	LOG_LOCK(log);
+	lmLogSync(log, 1);
+	LOG_UNLOCK(log);
+}
 
 /*
  * NAME:	lmLogOpen()

fs/jfs/jfs_logmgr.h

@@ -508,5 +508,6 @@ extern int lmLogShutdown(struct jfs_log * log);
 extern int lmLogInit(struct jfs_log * log);
 extern int lmLogFormat(struct jfs_log *log, s64 logAddress, int logSize);
 extern void jfs_flush_journal(struct jfs_log * log, int wait);
+extern void jfs_syncpt(struct jfs_log *log);
 
 #endif				/* _H_JFS_LOGMGR */

fs/jfs/jfs_txnmgr.c

@@ -567,25 +567,29 @@ void txEnd(tid_t tid)
 		 * synchronize with logsync barrier
 		 */
 		if (test_bit(log_SYNCBARRIER, &log->flag)) {
-			/* forward log syncpt */
-			/* lmSync(log); */
-
 			jfs_info("log barrier off: 0x%x", log->lsn);
 
 			/* enable new transactions start */
 			clear_bit(log_SYNCBARRIER, &log->flag);
 
 			/* wakeup all waitors for logsync barrier */
 			TXN_WAKEUP(&log->syncwait);
+
+			TXN_UNLOCK();
+
+			/* forward log syncpt */
+			jfs_syncpt(log);
+
+			goto wakeup;
 		}
 	}
 
+	TXN_UNLOCK();
+wakeup:
 	/*
 	 * wakeup all waitors for a free tblock
 	 */
 	TXN_WAKEUP(&TxAnchor.freewait);
-
-	TXN_UNLOCK();
 }
 
 

fs/jfs/super.c

@@ -558,8 +558,10 @@ static int jfs_sync_fs(struct super_block *sb, int wait)
 	struct jfs_log *log = JFS_SBI(sb)->log;
 
 	/* log == NULL indicates read-only mount */
-	if (log)
+	if (log) {
 		jfs_flush_journal(log, wait);
+		jfs_syncpt(log);
+	}
 
 	return 0;
 }