From 923e3aaf6f7474dac6ccc017302a6b20136f5d3f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Axel=20D=C3=B6rfler?= <axeld@pinc-software.de>
Date: Sat, 21 Jan 2006 13:35:08 +0000
Subject: [PATCH] Fixed two crucial bugs: * When aborting the first
 sub-transaction, BFS didn't recognize this   correctly, and aborted it via
 cache_abort_transaction() instead of   cache_abort_sub_transaction() - that
 not only reversed the whole   transaction, but also let subsequent
 cache_start_sub_transaction()   fail (as there was no transaction to continue
 anymore). Reported   in a reproducible way by Jerome Duval. * Haiku didn't
 want to replay logs anymore - the off-by-one fix I did   in r14428 was not
 complete, it only let Be's BFS replay our logs,   but our's rejected them
 afterwards.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16018 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/add-ons/kernel/file_systems/bfs/Journal.cpp | 10 ++++++++--
 src/add-ons/kernel/file_systems/bfs/Journal.h   |  3 ++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/add-ons/kernel/file_systems/bfs/Journal.cpp b/src/add-ons/kernel/file_systems/bfs/Journal.cpp
index 4a434c6e18..f7dc26c6a7 100644
--- a/src/add-ons/kernel/file_systems/bfs/Journal.cpp
+++ b/src/add-ons/kernel/file_systems/bfs/Journal.cpp
@@ -300,7 +300,8 @@ Journal::Journal(Volume *volume)
 	fLogSize(volume->Log().length),
 	fMaxTransactionSize(fLogSize / 4 - 5),
 	fUsed(0),
-	fUnwrittenTransactions(0)
+	fUnwrittenTransactions(0),
+	fHasSubtransaction(false)
 {
 	if (fMaxTransactionSize > fLogSize / 2)
 		fMaxTransactionSize = fLogSize / 2 - 5;
@@ -330,10 +331,13 @@ Journal::InitCheck()
 status_t
 Journal::_CheckRunArray(const run_array *array)
 {
-	int32 maxRuns = run_array::MaxRuns(fVolume->BlockSize());
+	int32 maxRuns = run_array::MaxRuns(fVolume->BlockSize()) - 1;
+		// the -1 works around an off-by-one bug in Be's BFS implementation,
+		// same as in run_array::MaxRuns()
 	if (array->MaxRuns() != maxRuns
 		|| array->CountRuns() > maxRuns
 		|| array->CountRuns() <= 0) {
+		dprintf("run count: %ld, array max: %ld, max runs: %ld\n", array->CountRuns(), array->MaxRuns(), maxRuns);
 		FATAL(("Log entry has broken header!\n"));
 		return B_ERROR;
 	}
@@ -507,6 +511,7 @@ Journal::_WriteTransactionToLog()
 	//	changed blocks back to disk immediately
 
 	fUnwrittenTransactions = 0;
+	fHasSubtransaction = false;
 
 	int32 blockShift = fVolume->BlockShift();
 	off_t logOffset = fVolume->ToBlock(fVolume->Log()) << blockShift;
@@ -721,6 +726,7 @@ Journal::Lock(Transaction *owner)
 	if (fUnwrittenTransactions > 0) {
 		// start a sub transaction
 		cache_start_sub_transaction(fVolume->BlockCache(), fTransactionID);
+		fHasSubtransaction = true;
 	} else
 		fTransactionID = cache_start_transaction(fVolume->BlockCache());
 
diff --git a/src/add-ons/kernel/file_systems/bfs/Journal.h b/src/add-ons/kernel/file_systems/bfs/Journal.h
index aa6690a2fa..8191a0db8c 100644
--- a/src/add-ons/kernel/file_systems/bfs/Journal.h
+++ b/src/add-ons/kernel/file_systems/bfs/Journal.h
@@ -60,7 +60,7 @@ class Journal {
 		inline uint32 FreeLogBlocks() const;
 
 	private:
-		bool _HasSubTransaction() { return fUnwrittenTransactions > 1; }
+		bool _HasSubTransaction() { return fHasSubtransaction; }
 		uint32 _TransactionSize() const;
 		status_t _WriteTransactionToLog();
 		status_t _CheckRunArray(const run_array *array);
@@ -77,6 +77,7 @@ class Journal {
 		LogEntryList	fEntries;
 		bigtime_t		fTimestamp;
 		int32			fTransactionID;
+		bool			fHasSubtransaction;
 };