From 772506f830c387b8468c67553df0b595e293d5ce Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Axel=20D=C3=B6rfler?= <axeld@pinc-software.de>
Date: Sat, 15 Mar 2008 16:35:10 +0000
Subject: [PATCH] Divided the _ReplayRunArray() method into two passes: first,
 the integrity of the blocks in the log entry will be checked, and only if
 this passed, all log entries are written back together; if the whole run
 array contained bad data, it's no longer written to disk at all if it's
 detectable.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24402 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 .../kernel/file_systems/bfs/Journal.cpp       | 40 +++++++++++++++----
 1 file changed, 33 insertions(+), 7 deletions(-)

diff --git a/src/add-ons/kernel/file_systems/bfs/Journal.cpp b/src/add-ons/kernel/file_systems/bfs/Journal.cpp
index 18eaeeea44..25dc47e078 100644
--- a/src/add-ons/kernel/file_systems/bfs/Journal.cpp
+++ b/src/add-ons/kernel/file_systems/bfs/Journal.cpp
@@ -367,6 +367,10 @@ Journal::InitCheck()
 }
 
 
+/*!	\brief Does a very basic consistency check of the run array.
+	It will check the maximum run count as well as if all of the runs fall
+	within a the volume.
+*/
 status_t
 Journal::_CheckRunArray(const run_array *array)
 {
@@ -402,27 +406,28 @@ Journal::_ReplayRunArray(int32 *_start)
 	PRINT(("ReplayRunArray(start = %ld)\n", *_start));
 
 	off_t logOffset = fVolume->ToBlock(fVolume->Log());
-	off_t blockNumber = *_start % fLogSize;
-	int32 blockSize = fVolume->BlockSize();
-	int32 count = 1;
+	off_t firstBlockNumber = *_start % fLogSize;
 
 	CachedBlock cachedArray(fVolume);
 
 	const run_array *array = (const run_array *)cachedArray.SetTo(logOffset
-		+ blockNumber);
+		+ firstBlockNumber);
 	if (array == NULL)
 		return B_IO_ERROR;
 
 	if (_CheckRunArray(array) < B_OK)
 		return B_BAD_DATA;
 
-	blockNumber = (blockNumber + 1) % fLogSize;
+	// First pass: check integrity of the blocks in the run array
 
 	CachedBlock cached(fVolume);
+
+	firstBlockNumber = (firstBlockNumber + 1) % fLogSize;
+	off_t blockNumber = firstBlockNumber;
+	int32 blockSize = fVolume->BlockSize();
+
 	for (int32 index = 0; index < array->CountRuns(); index++) {
 		const block_run &run = array->RunAt(index);
-		INFORM(("replay block run %u:%u:%u in log at %Ld!\n",
-			(int)run.AllocationGroup(), run.Start(), run.Length(), blockNumber));
 
 		off_t offset = fVolume->ToOffset(run);
 		for (int32 i = 0; i < run.Length(); i++) {
@@ -441,6 +446,27 @@ Journal::_ReplayRunArray(int32 *_start)
 				}
 			}
 
+			blockNumber = (blockNumber + 1) % fLogSize;
+			offset += blockSize;
+		}
+	}
+
+	// Second pass: write back its blocks
+
+	blockNumber = firstBlockNumber;
+	int32 count = 1;
+
+	for (int32 index = 0; index < array->CountRuns(); index++) {
+		const block_run &run = array->RunAt(index);
+		INFORM(("replay block run %u:%u:%u in log at %Ld!\n",
+			(int)run.AllocationGroup(), run.Start(), run.Length(), blockNumber));
+
+		off_t offset = fVolume->ToOffset(run);
+		for (int32 i = 0; i < run.Length(); i++) {
+			const uint8 *data = cached.SetTo(logOffset + blockNumber);
+			if (data == NULL)
+				RETURN_ERROR(B_IO_ERROR);
+
 			ssize_t written = write_pos(fVolume->Device(), offset, data,
 				blockSize);
 			if (written != blockSize)