>From d433e0479c9cde46b29b30a5c5996c1dbe57005f Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 10 Jan 2012 13:12:55 -0500 Subject: [PATCH] jbd: clear b_modified before moving the jh to a different transaction journal_forget() and journal_invalidatepage() functions move buffer to BJ_Forget list of a running transaction so that the buffer gets cleaned up when the transaction is committed. This usually happens when underlying block is freed but journal_invalidatepage() can also move the buffer when page cache of the corresponding inode (may be a block device) gets flushed. When the buffer had b_modfied set from the previous transaction and we happen to modify it again in the current transaction, we won't properly account for the modified buffer by subtracting the number of reserved credits of the running transaction because do_get_write_access() won't clear b_modified (buffer already is on running transaction so do_get_write_access() things it has nothing to do). This then results in assertion failure in commit code because the transaction has more buffers than reserved credits (t_nr_buffers > t_outstanding_credits). We fix the issue by clearing b_modified before moving buffer to a BJ_Forget list of another transaction because logically, it's not changed for that transaction anymore. CC: stable@kernel.org Signed-off-by: Josef Bacik Signed-off-by: Jan Kara --- fs/jbd/transaction.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c index febc10d..fb48e44 100644 --- a/fs/jbd/transaction.c +++ b/fs/jbd/transaction.c @@ -1788,6 +1788,7 @@ static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) */ clear_buffer_dirty(bh); __journal_file_buffer(jh, transaction, BJ_Forget); + jh->b_modified = 0; may_free = 0; } else { JBUFFER_TRACE(jh, "on running transaction"); @@ -1956,8 +1957,10 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) * clear dirty bits when it is done with the buffer. */ set_buffer_freed(bh); - if (journal->j_running_transaction && buffer_jbddirty(bh)) + if (journal->j_running_transaction && buffer_jbddirty(bh)) { + jh->b_modified = 0; jh->b_next_transaction = journal->j_running_transaction; + } journal_put_journal_head(jh); spin_unlock(&journal->j_list_lock); jbd_unlock_bh_state(bh); -- 1.7.1