hi!
I think current journal_release_buffer() which is used by ext3 allocator
in -mm tree has a bug. look, it won't decrement credits if concurrent
thread already put buffer on metadata list. but this may ext3_try_to_allocate()
may overflow handle's credist.
so, jbd will hit J_ASSERT_JH(jh, handle->h_buffer_credits > 0) somewhere
void journal_release_buffer (handle_t *handle, struct buffer_head *bh)
{
.....
if (jh->b_jlist == BJ_Reserved && jh->b_transaction == transaction &&
!buffer_jdirty(jh2bh(jh))) {
JBUFFER_TRACE(jh, "unused: refiling it");
handle->h_buffer_credits++;
__journal_refile_buffer(jh);
}
....
}
here is the patch against 2.5.69-mm6:
diff -puNr linux-2.5.69-mm6/fs/jbd/transaction.c edited/fs/jbd/transaction.c
--- linux-2.5.69-mm6/fs/jbd/transaction.c Fri May 16 18:03:20 2003
+++ b_commited_data-race/fs/jbd/transaction.c Fri May 23 11:10:21 2003
@@ -1146,10 +1146,10 @@ void journal_release_buffer (handle_t *h
if (jh->b_jlist == BJ_Reserved && jh->b_transaction == transaction &&
!buffer_jdirty(jh2bh(jh))) {
JBUFFER_TRACE(jh, "unused: refiling it");
- handle->h_buffer_credits++;
__journal_refile_buffer(jh);
}
spin_unlock(&journal_datalist_lock);
+ handle->h_buffer_credits++;
JBUFFER_TRACE(jh, "exit");
unlock_journal(journal);
-
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This archive was generated by hypermail 2b29 : Fri May 23 2003 - 22:00:53 EST