From 8c3f25d8950c3e9fe6c9849f88679b3f2a071550 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 6 Nov 2008 22:38:07 -0500 Subject: [PATCH] jbd2: don't give up looking for space so easily in __jbd2_log_wait_for_space MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Commit 23f8b79e introducd a regression because it assumed that if there were no transactions ready to be checkpointed, that no progress could be made on making space available in the journal, and so the journal should be aborted. This assumption is false; it could be the case that simply calling jbd2_cleanup_journal_tail() will recover the necessary space, or, for small journals, the currently committing transaction could be responsible for chewing up the required space in the log, so we need to wait for the currently committing transaction to finish before trying to force a checkpoint operation. This patch fixes a bug reported by Mihai Harpau at: https://bugzilla.redhat.com/show_bug.cgi?id=469582 This patch fixes a bug reported by François Valenduc at: http://bugzilla.kernel.org/show_bug.cgi?id=11840 Signed-off-by: "Theodore Ts'o" Cc: Duane Griffin Cc: Toshiyuki Okajima --- fs/jbd2/checkpoint.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index 9203c3332f1..9497718fe92 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -116,7 +116,7 @@ static int __try_to_free_cp_buf(struct journal_head *jh) */ void __jbd2_log_wait_for_space(journal_t *journal) { - int nblocks; + int nblocks, space_left; assert_spin_locked(&journal->j_state_lock); nblocks = jbd_space_needed(journal); @@ -129,25 +129,43 @@ void __jbd2_log_wait_for_space(journal_t *journal) /* * Test again, another process may have checkpointed while we * 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. + * transactions ready to be checkpointed, try to recover + * journal space by calling cleanup_journal_tail(), and if + * that doesn't work, by waiting for the currently committing + * transaction to complete. If there is absolutely no way + * to make progress, this is either a BUG or corrupted + * filesystem, so abort the journal and leave a stack + * trace for forensic evidence. */ spin_lock(&journal->j_state_lock); spin_lock(&journal->j_list_lock); nblocks = jbd_space_needed(journal); - if (__jbd2_log_space_left(journal) < nblocks) { + space_left = __jbd2_log_space_left(journal); + if (space_left < nblocks) { int chkpt = journal->j_checkpoint_transactions != NULL; + tid_t tid = 0; + if (journal->j_committing_transaction) + tid = journal->j_committing_transaction->t_tid; spin_unlock(&journal->j_list_lock); spin_unlock(&journal->j_state_lock); if (chkpt) { jbd2_log_do_checkpoint(journal); + } else if (jbd2_cleanup_journal_tail(journal) == 0) { + /* We were able to recover space; yay! */ + ; + } else if (tid) { + jbd2_log_wait_commit(journal, tid); } else { - printk(KERN_ERR "%s: no transactions\n", - __func__); + printk(KERN_ERR "%s: needed %d blocks and " + "only had %d space available\n", + __func__, nblocks, space_left); + printk(KERN_ERR "%s: no way to get more " + "journal space in %s\n", __func__, + journal->j_devname); + WARN_ON(1); jbd2_journal_abort(journal, 0); } - spin_lock(&journal->j_state_lock); } else { spin_unlock(&journal->j_list_lock); -- 2.41.1