From e219cca082f52e7dfea41f3be264b7b5eb204227 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 6 Nov 2008 22:37:59 -0500 Subject: jbd: don't give up looking for space so easily in __log_wait_for_space Commit be07c4ed 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 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 the bug reported by Meelis Roos at: http://bugzilla.kernel.org/show_bug.cgi?id=11937 Signed-off-by: "Theodore Ts'o" Cc: Duane Griffin Cc: Toshiyuki Okajima --- fs/jbd/checkpoint.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c index 1bd8d4a..61f32f3 100644 --- a/fs/jbd/checkpoint.c +++ b/fs/jbd/checkpoint.c @@ -115,7 +115,7 @@ static int __try_to_free_cp_buf(struct journal_head *jh) */ void __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); @@ -128,25 +128,42 @@ void __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 (__log_space_left(journal) < nblocks) { + space_left = __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) { log_do_checkpoint(journal); + } else if (cleanup_journal_tail(journal) == 0) { + /* We were able to recover space; yay! */ + ; + } else if (tid) { + 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\n", __func__); + WARN_ON(1); journal_abort(journal, 0); } - spin_lock(&journal->j_state_lock); } else { spin_unlock(&journal->j_list_lock); -- cgit v1.1