From: Theodore Ts'o Subject: [FOR-STABLE 09/20] jbd2: abort instead of waiting for nonexistent transaction Date: Sun, 16 Nov 2008 11:05:29 -0500 Message-ID: <1226851540-8032-10-git-send-email-tytso@mit.edu> References: <1226851540-8032-1-git-send-email-tytso@mit.edu> <1226851540-8032-2-git-send-email-tytso@mit.edu> <1226851540-8032-3-git-send-email-tytso@mit.edu> <1226851540-8032-4-git-send-email-tytso@mit.edu> <1226851540-8032-5-git-send-email-tytso@mit.edu> <1226851540-8032-6-git-send-email-tytso@mit.edu> <1226851540-8032-7-git-send-email-tytso@mit.edu> <1226851540-8032-8-git-send-email-tytso@mit.edu> <1226851540-8032-9-git-send-email-tytso@mit.edu> Cc: Ext4 Developers List , Duane Griffin , Sami Liedes , Andrew Morton , "Theodore Ts'o" To: stable@kernel.org Return-path: Received: from www.church-of-our-saviour.ORG ([69.25.196.31]:44697 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753362AbYKPQgE (ORCPT ); Sun, 16 Nov 2008 11:36:04 -0500 In-Reply-To: <1226851540-8032-9-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Duane Griffin The __jbd2_log_wait_for_space function sits in a loop checkpointing transactions until there is sufficient space free in the journal. However, if there are no transactions to be processed (e.g. because the free space calculation is wrong due to a corrupted filesystem) it will never progress. Check for space being required when no transactions are outstanding and abort the journal instead of endlessly looping. This patch fixes the bug reported by Sami Liedes at: http://bugzilla.kernel.org/show_bug.cgi?id=10976 Signed-off-by: Duane Griffin Cc: Sami Liedes Cc: Signed-off-by: Andrew Morton Signed-off-by: "Theodore Ts'o" (cherry picked from commit 23f8b79eae8a74e42a006ffa7c456e295c7e1c0d) --- fs/jbd2/checkpoint.c | 19 +++++++++++++++++-- 1 files changed, 17 insertions(+), 2 deletions(-) diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index 91389c8..af4651b 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -126,14 +126,29 @@ void __jbd2_log_wait_for_space(journal_t *journal) /* * Test again, another process may have checkpointed while we - * were waiting for the checkpoint lock + * were waiting for the checkpoint lock. If there are no + * outstanding transactions there is nothing to checkpoint and + * we can't make progress. Abort the journal in this case. */ spin_lock(&journal->j_state_lock); + spin_lock(&journal->j_list_lock); nblocks = jbd_space_needed(journal); if (__jbd2_log_space_left(journal) < nblocks) { + int chkpt = journal->j_checkpoint_transactions != NULL; + + spin_unlock(&journal->j_list_lock); spin_unlock(&journal->j_state_lock); - jbd2_log_do_checkpoint(journal); + if (chkpt) { + jbd2_log_do_checkpoint(journal); + } else { + printk(KERN_ERR "%s: no transactions\n", + __func__); + jbd2_journal_abort(journal, 0); + } + spin_lock(&journal->j_state_lock); + } else { + spin_unlock(&journal->j_list_lock); } mutex_unlock(&journal->j_checkpoint_mutex); } -- 1.6.0.4.8.g36f27.dirty