Aren/haiku
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fixed the new issue in #8910 from r44585.

Browse Source 
* The ASSERT() I introduced in r44585 was incorrect: when the sub transaction
  used block_cache_get_empty() to get the block, there is no original_data for
  a reason.
* Added a test case that reproduces this situation.
* The block must be moved to the unused list in this situation, though, or else
  it might contain invalid data. Since the block can only be allocated in the
  current transaction, this should not be a problem, though, AFAICT.
This commit is contained in:
Axel Dörfler 2012-09-04 00:54:25 +02:00
parent e85dfa6bad
commit 098967cee1
2 changed files with 45 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/system/kernel/cache/block_cache.cpp vendored
View File

@ -3046,9 +3046,11 @@ cache_abort_sub_transaction(void* _cache, int32 id)
// The parent transaction didn't change the block, but the sub
// transaction did - we need to revert to the original data.
// The block is no longer part of the transaction
ASSERT(block->original_data != NULL);
memcpy(block->current_data, block->original_data,
cache->block_size);
if (block->original_data != NULL) {
// The block might not have original data if was empty
memcpy(block->current_data, block->original_data,
cache->block_size);
}
if (last != NULL)
last->transaction_next = next;

41
src/tests/system/kernel/cache/block_cache_test.cpp vendored
View File

@ -1,5 +1,5 @@
/*
* Copyright 2008, Axel Dörfler, axeld@pinc-software.de.
* Copyright 2008-2012, Axel Dörfler, axeld@pinc-software.de.
* Distributed under the terms of the MIT License.
*/
@ -400,6 +400,45 @@ test_abort_sub_transaction()
cache_end_transaction(gCache, id, NULL, NULL);
cache_sync_transaction(gCache, id);
start_test("Abort sub with empty block");
id = cache_start_transaction(gCache);
gBlocks[1].present = true;
gBlocks[1].read = true;
block = block_cache_get_writable(gCache, 1, id);
or_block(block, BLOCK_CHANGED_IN_PREVIOUS);
gBlocks[1].original = gBlocks[1].current;
gBlocks[1].current |= BLOCK_CHANGED_IN_PREVIOUS;
block_cache_put(gCache, 1);
gBlocks[1].is_dirty = true;
TEST_BLOCKS(1, 1);
cache_start_sub_transaction(gCache, id);
gBlocks[0].present = true;
block = block_cache_get_empty(gCache, 0, id);
or_block(block, BLOCK_CHANGED_IN_SUB);
gBlocks[0].current = BLOCK_CHANGED_IN_SUB;
block_cache_put(gCache, 0);
cache_abort_sub_transaction(gCache, id);
gBlocks[0].write = false;
gBlocks[0].is_dirty = false;
gBlocks[0].parent = 0;
gBlocks[0].original = 0;
TEST_BLOCKS(0, 1);
gBlocks[1].write = true;
gBlocks[1].is_dirty = false;
cache_end_transaction(gCache, id, NULL, NULL);
cache_sync_transaction(gCache, id);
}